diff options
Diffstat (limited to 'paramiko')
| -rw-r--r-- | paramiko/__init__.py | 146 | ||||
| -rw-r--r-- | paramiko/agent.py | 138 | ||||
| -rw-r--r-- | paramiko/auth_handler.py | 410 | ||||
| -rw-r--r-- | paramiko/ber.py | 128 | ||||
| -rw-r--r-- | paramiko/channel.py | 1174 | ||||
| -rw-r--r-- | paramiko/common.py | 136 | ||||
| -rw-r--r-- | paramiko/compress.py | 39 | ||||
| -rw-r--r-- | paramiko/dsskey.py | 176 | ||||
| -rw-r--r-- | paramiko/file.py | 440 | ||||
| -rw-r--r-- | paramiko/kex_gex.py | 202 | ||||
| -rw-r--r-- | paramiko/kex_group1.py | 136 | ||||
| -rw-r--r-- | paramiko/logging22.py | 66 | ||||
| -rw-r--r-- | paramiko/message.py | 301 | ||||
| -rw-r--r-- | paramiko/packet.py | 442 | ||||
| -rw-r--r-- | paramiko/pipe.py | 105 | ||||
| -rw-r--r-- | paramiko/pkey.py | 339 | ||||
| -rw-r--r-- | paramiko/primes.py | 148 | ||||
| -rw-r--r-- | paramiko/rsakey.py | 165 | ||||
| -rw-r--r-- | paramiko/server.py | 527 | ||||
| -rw-r--r-- | paramiko/sftp.py | 168 | ||||
| -rw-r--r-- | paramiko/sftp_attr.py | 208 | ||||
| -rw-r--r-- | paramiko/sftp_client.py | 618 | ||||
| -rw-r--r-- | paramiko/sftp_file.py | 307 | ||||
| -rw-r--r-- | paramiko/sftp_handle.py | 188 | ||||
| -rw-r--r-- | paramiko/sftp_server.py | 420 | ||||
| -rw-r--r-- | paramiko/sftp_si.py | 303 | ||||
| -rw-r--r-- | paramiko/ssh_exception.py | 69 | ||||
| -rw-r--r-- | paramiko/transport.py | 1824 | ||||
| -rw-r--r-- | paramiko/util.py | 357 |
29 files changed, 9680 insertions, 0 deletions
diff --git a/paramiko/__init__.py b/paramiko/__init__.py new file mode 100644 index 0000000..0a312cb --- /dev/null +++ b/paramiko/__init__.py @@ -0,0 +1,146 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +I{Paramiko} (a combination of the esperanto words for "paranoid" and "friend") +is a module for python 2.3 or greater that implements the SSH2 protocol for +secure (encrypted and authenticated) connections to remote machines. Unlike +SSL (aka TLS), the SSH2 protocol does not require heirarchical certificates +signed by a powerful central authority. You may know SSH2 as the protocol that +replaced C{telnet} and C{rsh} for secure access to remote shells, but the +protocol also includes the ability to open arbitrary channels to remote +services across an encrypted tunnel. (This is how C{sftp} works, for example.) + +To use this package, pass a socket (or socket-like object) to a L{Transport}, +and use L{start_server <Transport.start_server>} or +L{start_client <Transport.start_client>} to negoatite +with the remote host as either a server or client. As a client, you are +responsible for authenticating using a password or private key, and checking +the server's host key. I{(Key signature and verification is done by paramiko, +but you will need to provide private keys and check that the content of a +public key matches what you expected to see.)} As a server, you are +responsible for deciding which users, passwords, and keys to allow, and what +kind of channels to allow. + +Once you have finished, either side may request flow-controlled L{Channel}s to +the other side, which are python objects that act like sockets, but send and +receive data over the encrypted session. + +Paramiko is written entirely in python (no C or platform-dependent code) and is +released under the GNU Lesser General Public License (LGPL). + +Website: U{http://www.lag.net/paramiko/} + +@version: 1.5.2 (rhydon) +@author: Robey Pointer +@contact: robey@lag.net +@license: GNU Lesser General Public License (LGPL) +""" + +import sys + +if sys.version_info < (2, 2): + raise RuntimeError('You need python 2.2 for this module.') + + +__author__ = "Robey Pointer <robey@lag.net>" +__date__ = "04 Dec 2005" +__version__ = "1.5.2 (rhydon)" +__version_info__ = (1, 5, 2) +__license__ = "GNU Lesser General Public License (LGPL)" + + +import transport, auth_handler, channel, rsakey, dsskey, message +import ssh_exception, file, packet, agent, server, util +import sftp_client, sftp_attr, sftp_handle, sftp_server, sftp_si + +from transport import randpool, SecurityOptions, Transport +from auth_handler import AuthHandler +from channel import Channel, ChannelFile +from ssh_exception import SSHException, PasswordRequiredException, BadAuthenticationType +from server import ServerInterface, SubsystemHandler, InteractiveQuery +from rsakey import RSAKey +from dsskey import DSSKey +from sftp import SFTPError, BaseSFTP +from sftp_client import SFTP, SFTPClient +from sftp_server import SFTPServer +from sftp_attr import SFTPAttributes +from sftp_handle import SFTPHandle +from sftp_si import SFTPServerInterface +from sftp_file import SFTPFile +from message import Message +from packet import Packetizer +from file import BufferedFile +from agent import Agent, AgentKey +from pkey import PKey + +# fix module names for epydoc +for x in [Transport, SecurityOptions, Channel, SFTPServer, SSHException, \ + PasswordRequiredException, BadAuthenticationType, ChannelFile, \ + SubsystemHandler, AuthHandler, RSAKey, DSSKey, SFTPError, \ + SFTP, SFTPClient, SFTPServer, Message, Packetizer, SFTPAttributes, \ + SFTPHandle, SFTPServerInterface, BufferedFile, Agent, AgentKey, \ + PKey, BaseSFTP, SFTPFile, ServerInterface]: + x.__module__ = 'paramiko' + +from common import AUTH_SUCCESSFUL, AUTH_PARTIALLY_SUCCESSFUL, AUTH_FAILED, \ + OPEN_SUCCEEDED, OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED, OPEN_FAILED_CONNECT_FAILED, \ + OPEN_FAILED_UNKNOWN_CHANNEL_TYPE, OPEN_FAILED_RESOURCE_SHORTAGE + +from sftp import SFTP_OK, SFTP_EOF, SFTP_NO_SUCH_FILE, SFTP_PERMISSION_DENIED, SFTP_FAILURE, \ + SFTP_BAD_MESSAGE, SFTP_NO_CONNECTION, SFTP_CONNECTION_LOST, SFTP_OP_UNSUPPORTED + +__all__ = [ 'Transport', + 'SecurityOptions', + 'SubsystemHandler', + 'Channel', + 'RSAKey', + 'DSSKey', + 'Agent', + 'Message', + 'SSHException', + 'PasswordRequiredException', + 'BadAuthenticationType', + 'SFTP', + 'SFTPFile', + 'SFTPHandle', + 'SFTPClient', + 'SFTPServer', + 'SFTPError', + 'SFTPAttributes', + 'SFTPServerInterface' + 'ServerInterface', + 'BufferedFile', + 'Agent', + 'AgentKey', + 'rsakey', + 'dsskey', + 'pkey', + 'message', + 'transport', + 'sftp', + 'sftp_client', + 'sftp_server', + 'sftp_attr', + 'sftp_file', + 'sftp_si', + 'sftp_handle', + 'server', + 'file', + 'agent', + 'util' ] diff --git a/paramiko/agent.py b/paramiko/agent.py new file mode 100644 index 0000000..3555512 --- /dev/null +++ b/paramiko/agent.py @@ -0,0 +1,138 @@ +# Copyright (C) 2003-2005 John Rochester <john@jrochester.org> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +SSH Agent interface for Unix clients. +""" + +import os +import socket +import struct +import sys + +from paramiko.ssh_exception import SSHException +from paramiko.message import Message +from paramiko.pkey import PKey + + +SSH2_AGENTC_REQUEST_IDENTITIES, SSH2_AGENT_IDENTITIES_ANSWER, \ + SSH2_AGENTC_SIGN_REQUEST, SSH2_AGENT_SIGN_RESPONSE = range(11, 15) + + +class Agent: + """ + Client interface for using private keys from an SSH agent running on the + local machine. If an SSH agent is running, this class can be used to + connect to it and retreive L{PKey} objects which can be used when + attempting to authenticate to remote SSH servers. + + Because the SSH agent protocol uses environment variables and unix-domain + sockets, this probably doesn't work on Windows. It does work on most + posix platforms though (Linux and MacOS X, for example). + """ + + def __init__(self): + """ + Open a session with the local machine's SSH agent, if one is running. + If no agent is running, initialization will succeed, but L{get_keys} + will return an empty tuple. + + @raise SSHException: if an SSH agent is found, but speaks an + incompatible protocol + """ + if ('SSH_AUTH_SOCK' in os.environ) and (sys.platform != 'win32'): + conn = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) + conn.connect(os.environ['SSH_AUTH_SOCK']) + self.conn = conn + type, result = self._send_message(chr(SSH2_AGENTC_REQUEST_IDENTITIES)) + if type != SSH2_AGENT_IDENTITIES_ANSWER: + raise SSHException('could not get keys from ssh-agent') + keys = [] + for i in range(result.get_int()): + keys.append(AgentKey(self, result.get_string())) + result.get_string() + self.keys = tuple(keys) + else: + self.keys = () + + def close(self): + """ + Close the SSH agent connection. + """ + self.conn.close() + self.conn = None + self.keys = () + + def get_keys(self): + """ + Return the list of keys available through the SSH agent, if any. If + no SSH agent was running (or it couldn't be contacted), an empty list + will be returned. + + @return: a list of keys available on the SSH agent + @rtype: tuple of L{AgentKey} + """ + return self.keys + + def _send_message(self, msg): + msg = str(msg) + self.conn.send(struct.pack('>I', len(msg)) + msg) + l = self._read_all(4) + msg = Message(self._read_all(struct.unpack('>I', l)[0])) + return ord(msg.get_byte()), msg + + def _read_all(self, wanted): + result = self.conn.recv(wanted) + while len(result) < wanted: + if len(result) == 0: + raise SSHException('lost ssh-agent') + extra = self.conn.recv(wanted - len(result)) + if len(extra) == 0: + raise SSHException('lost ssh-agent') + result += extra + return result + + +class AgentKey(PKey): + """ + Private key held in a local SSH agent. This type of key can be used for + authenticating to a remote server (signing). Most other key operations + work as expected. + """ + + def __init__(self, agent, blob): + self.agent = agent + self.blob = blob + self.name = Message(blob).get_string() + + def __str__(self): + return self.blob + + def get_name(self): + return self.name + + def sign_ssh_data(self, randpool, data): + msg = Message() + msg.add_byte(chr(SSH2_AGENTC_SIGN_REQUEST)) + msg.add_string(self.blob) + msg.add_string(data) + msg.add_int(0) + type, result = self.agent._send_message(msg) + if type != SSH2_AGENT_SIGN_RESPONSE: + raise SSHException('key cannot be used for signing') + return result.get_string() diff --git a/paramiko/auth_handler.py b/paramiko/auth_handler.py new file mode 100644 index 0000000..59aa376 --- /dev/null +++ b/paramiko/auth_handler.py @@ -0,0 +1,410 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{AuthHandler} +""" + +import threading + +# this helps freezing utils +import encodings.utf_8 + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ssh_exception import SSHException, BadAuthenticationType, PartialAuthentication +from paramiko.server import InteractiveQuery + + +class AuthHandler (object): + """ + Internal class to handle the mechanics of authentication. + """ + + def __init__(self, transport): + self.transport = transport + self.username = None + self.authenticated = False + self.auth_event = None + self.auth_method = '' + self.password = None + self.private_key = None + # for server mode: + self.auth_username = None + self.auth_fail_count = 0 + + def is_authenticated(self): + return self.authenticated + + def get_username(self): + if self.transport.server_mode: + return self.auth_username + else: + return self.username + + def auth_none(self, username, event): + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'none' + self.username = username + self._request_auth() + finally: + self.transport.lock.release() + + def auth_publickey(self, username, key, event): + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'publickey' + self.username = username + self.private_key = key + self._request_auth() + finally: + self.transport.lock.release() + + def auth_password(self, username, password, event): + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'password' + self.username = username + self.password = password + self._request_auth() + finally: + self.transport.lock.release() + + def auth_interactive(self, username, handler, event, submethods=''): + """ + response_list = handler(title, instructions, prompt_list) + """ + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'keyboard-interactive' + self.username = username + self.interactive_handler = handler + self.submethods = submethods + self._request_auth() + finally: + self.transport.lock.release() + + def abort(self): + if self.auth_event is not None: + self.auth_event.set() + + + ### internals... + + + def _request_auth(self): + m = Message() + m.add_byte(chr(MSG_SERVICE_REQUEST)) + m.add_string('ssh-userauth') + self.transport._send_message(m) + + def _disconnect_service_not_available(self): + m = Message() + m.add_byte(chr(MSG_DISCONNECT)) + m.add_int(DISCONNECT_SERVICE_NOT_AVAILABLE) + m.add_string('Service not available') + m.add_string('en') + self.transport._send_message(m) + self.transport.close() + + def _disconnect_no_more_auth(self): + m = Message() + m.add_byte(chr(MSG_DISCONNECT)) + m.add_int(DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE) + m.add_string('No more auth methods available') + m.add_string('en') + self.transport._send_message(m) + self.transport.close() + + def _get_session_blob(self, key, service, username): + m = Message() + m.add_string(self.transport.session_id) + m.add_byte(chr(MSG_USERAUTH_REQUEST)) + m.add_string(username) + m.add_string(service) + m.add_string('publickey') + m.add_boolean(1) + m.add_string(key.get_name()) + m.add_string(str(key)) + return str(m) + + def wait_for_response(self, event): + while True: + event.wait(0.1) + if not self.transport.is_active(): + e = self.transport.get_exception() + if e is None: + e = SSHException('Authentication failed.') + raise e + if event.isSet(): + break + if not self.is_authenticated(): + e = self.transport.get_exception() + if e is None: + e = SSHException('Authentication failed.') + # this is horrible. python Exception isn't yet descended from + # object, so type(e) won't work. :( + if issubclass(e.__class__, PartialAuthentication): + return e.allowed_types + raise e + return [] + + def _parse_service_request(self, m): + service = m.get_string() + if self.transport.server_mode and (service == 'ssh-userauth'): + # accepted + m = Message() + m.add_byte(chr(MSG_SERVICE_ACCEPT)) + m.add_string(service) + self.transport._send_message(m) + return + # dunno this one + self._disconnect_service_not_available() + + def _parse_service_accept(self, m): + service = m.get_string() + if service == 'ssh-userauth': + self.transport._log(DEBUG, 'userauth is OK') + m = Message() + m.add_byte(chr(MSG_USERAUTH_REQUEST)) + m.add_string(self.username) + m.add_string('ssh-connection') + m.add_string(self.auth_method) + if self.auth_method == 'password': + m.add_boolean(False) + m.add_string(self.password.encode('UTF-8')) + elif self.auth_method == 'publickey': + m.add_boolean(True) + m.add_string(self.private_key.get_name()) + m.add_string(str(self.private_key)) + blob = self._get_session_blob(self.private_key, 'ssh-connection', self.username) + sig = self.private_key.sign_ssh_data(self.transport.randpool, blob) + m.add_string(str(sig)) + elif self.auth_method == 'keyboard-interactive': + m.add_string('') + m.add_string(self.submethods) + elif self.auth_method == 'none': + pass + else: + raise SSHException('Unknown auth method "%s"' % self.auth_method) + self.transport._send_message(m) + else: + self.transport._log(DEBUG, 'Service request "%s" accepted (?)' % service) + + def _send_auth_result(self, username, method, result): + # okay, send result + m = Message() + if result == AUTH_SUCCESSFUL: + self.transport._log(INFO, 'Auth granted (%s).' % method) + m.add_byte(chr(MSG_USERAUTH_SUCCESS)) + self.authenticated = True + else: + self.transport._log(INFO, 'Auth rejected (%s).' % method) + m.add_byte(chr(MSG_USERAUTH_FAILURE)) + m.add_string(self.transport.server_object.get_allowed_auths(username)) + if result == AUTH_PARTIALLY_SUCCESSFUL: + m.add_boolean(1) + else: + m.add_boolean(0) + self.auth_fail_count += 1 + self.transport._send_message(m) + if self.auth_fail_count >= 10: + self._disconnect_no_more_auth() + if result == AUTH_SUCCESSFUL: + self.transport._auth_trigger() + + def _interactive_query(self, q): + # make interactive query instead of response + m = Message() + m.add_byte(chr(MSG_USERAUTH_INFO_REQUEST)) + m.add_string(q.name) + m.add_string(q.instructions) + m.add_string('') + m.add_int(len(q.prompts)) + for p in q.prompts: + m.add_string(p[0]) + m.add_boolean(p[1]) + self.transport._send_message(m) + + def _parse_userauth_request(self, m): + if not self.transport.server_mode: + # er, uh... what? + m = Message() + m.add_byte(chr(MSG_USERAUTH_FAILURE)) + m.add_string('none') + m.add_boolean(0) + self.transport._send_message(m) + return + if self.authenticated: + # ignore + return + username = m.get_string() + service = m.get_string() + method = m.get_string() + self.transport._log(DEBUG, 'Auth request (type=%s) service=%s, username=%s' % (method, service, username)) + if service != 'ssh-connection': + self._disconnect_service_not_available() + return + if (self.auth_username is not None) and (self.auth_username != username): + self.transport._log(WARNING, 'Auth rejected because the client attempted to change username in mid-flight') + self._disconnect_no_more_auth() + return + self.auth_username = username + + if method == 'none': + result = self.transport.server_object.check_auth_none(username) + elif method == 'password': + changereq = m.get_boolean() + password = m.get_string().decode('UTF-8', 'replace') + if changereq: + # always treated as failure, since we don't support changing passwords, but collect + # the list of valid auth types from the callback anyway + self.transport._log(DEBUG, 'Auth request to change passwords (rejected)') + newpassword = m.get_string().decode('UTF-8', 'replace') + result = AUTH_FAILED + else: + result = self.transport.server_object.check_auth_password(username, password) + elif method == 'publickey': + sig_attached = m.get_boolean() + keytype = m.get_string() + keyblob = m.get_string() + try: + key = self.transport._key_info[keytype](Message(keyblob)) + except SSHException, e: + self.transport._log(INFO, 'Auth rejected: public key: %s' % str(e)) + key = None + except: + self.transport._log(INFO, 'Auth rejected: unsupported or mangled public key') + key = None + if key is None: + self._disconnect_no_more_auth() + return + # first check if this key is okay... if not, we can skip the verify + result = self.transport.server_object.check_auth_publickey(username, key) + if result != AUTH_FAILED: + # key is okay, verify it + if not sig_attached: + # client wants to know if this key is acceptable, before it + # signs anything... send special "ok" message + m = Message() + m.add_byte(chr(MSG_USERAUTH_PK_OK)) + m.add_string(keytype) + m.add_string(keyblob) + self.transport._send_message(m) + return + sig = Message(m.get_string()) + blob = self._get_session_blob(key, service, username) + if not key.verify_ssh_sig(blob, sig): + self.transport._log(INFO, 'Auth rejected: invalid signature') + result = AUTH_FAILED + elif method == 'keyboard-interactive': + lang = m.get_string() + submethods = m.get_string() + result = self.transport.server_object.check_auth_interactive(username, submethods) + if isinstance(result, InteractiveQuery): + # make interactive query instead of response + self._interactive_query(result) + return + else: + result = self.transport.server_object.check_auth_none(username) + # okay, send result + self._send_auth_result(username, method, result) + + def _parse_userauth_success(self, m): + self.transport._log(INFO, 'Authentication successful!') + self.authenticated = True + self.transport._auth_trigger() + if self.auth_event != None: + self.auth_event.set() + + def _parse_userauth_failure(self, m): + authlist = m.get_list() + partial = m.get_boolean() + if partial: + self.transport._log(INFO, 'Authentication continues...') + self.transport._log(DEBUG, 'Methods: ' + str(authlist)) + self.transport.saved_exception = PartialAuthentication(authlist) + elif self.auth_method not in authlist: + self.transport._log(INFO, 'Authentication type not permitted.') + self.transport._log(DEBUG, 'Allowed methods: ' + str(authlist)) + self.transport.saved_exception = BadAuthenticationType('Bad authentication type', authlist) + else: + self.transport._log(INFO, 'Authentication failed.') + self.authenticated = False + self.username = None + if self.auth_event != None: + self.auth_event.set() + + def _parse_userauth_banner(self, m): + banner = m.get_string() + lang = m.get_string() + self.transport._log(INFO, 'Auth banner: ' + banner) + # who cares. + + def _parse_userauth_info_request(self, m): + if self.auth_method != 'keyboard-interactive': + raise SSHException('Illegal info request from server') + title = m.get_string() + instructions = m.get_string() + m.get_string() # lang + prompts = m.get_int() + prompt_list = [] + for i in range(prompts): + prompt_list.append((m.get_string(), m.get_boolean())) + response_list = self.interactive_handler(title, instructions, prompt_list) + + m = Message() + m.add_byte(chr(MSG_USERAUTH_INFO_RESPONSE)) + m.add_int(len(response_list)) + for r in response_list: + m.add_string(r) + self.transport._send_message(m) + + def _parse_userauth_info_response(self, m): + if not self.transport.server_mode: + raise SSHException('Illegal info response from server') + n = m.get_int() + responses = [] + for i in range(n): + responses.append(m.get_string()) + result = self.transport.server_object.check_auth_interactive_response(responses) + if isinstance(type(result), InteractiveQuery): + # make interactive query instead of response + self._interactive_query(result) + return + self._send_auth_result(self.auth_username, 'keyboard-interactive', result) + + + _handler_table = { + MSG_SERVICE_REQUEST: _parse_service_request, + MSG_SERVICE_ACCEPT: _parse_service_accept, + MSG_USERAUTH_REQUEST: _parse_userauth_request, + MSG_USERAUTH_SUCCESS: _parse_userauth_success, + MSG_USERAUTH_FAILURE: _parse_userauth_failure, + MSG_USERAUTH_BANNER: _parse_userauth_banner, + MSG_USERAUTH_INFO_REQUEST: _parse_userauth_info_request, + MSG_USERAUTH_INFO_RESPONSE: _parse_userauth_info_response, + } + + diff --git a/paramiko/ber.py b/paramiko/ber.py new file mode 100644 index 0000000..6a7823d --- /dev/null +++ b/paramiko/ber.py @@ -0,0 +1,128 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +import struct +import util + + +class BERException (Exception): + pass + + +class BER(object): + """ + Robey's tiny little attempt at a BER decoder. + """ + + def __init__(self, content=''): + self.content = content + self.idx = 0 + + def __str__(self): + return self.content + + def __repr__(self): + return 'BER(\'' + repr(self.content) + '\')' + + def decode(self): + return self.decode_next() + + def decode_next(self): + if self.idx >= len(self.content): + return None + ident = ord(self.content[self.idx]) + self.idx += 1 + if (ident & 31) == 31: + # identifier > 30 + ident = 0 + while self.idx < len(self.content): + t = ord(self.content[self.idx]) + self.idx += 1 + ident = (ident << 7) | (t & 0x7f) + if not (t & 0x80): + break + if self.idx >= len(self.content): + return None + # now fetch length + size = ord(self.content[self.idx]) + self.idx += 1 + if size & 0x80: + # more complimicated... + # FIXME: theoretically should handle indefinite-length (0x80) + t = size & 0x7f + if self.idx + t > len(self.content): + return None + size = util.inflate_long(self.content[self.idx : self.idx + t], True) + self.idx += t + if self.idx + size > len(self.content): + # can't fit + return None + data = self.content[self.idx : self.idx + size] + self.idx += size + # now switch on id + if ident == 0x30: + # sequence + return self.decode_sequence(data) + elif ident == 2: + # int + return util.inflate_long(data) + else: + # 1: boolean (00 false, otherwise true) + raise BERException('Unknown ber encoding type %d (robey is lazy)' % ident) + + def decode_sequence(data): + out = [] + b = BER(data) + while True: + x = b.decode_next() + if x is None: + return out + out.append(x) + decode_sequence = staticmethod(decode_sequence) + + def encode_tlv(self, ident, val): + # no need to support ident > 31 here + self.content += chr(ident) + if len(val) > 0x7f: + lenstr = util.deflate_long(len(val)) + self.content += chr(0x80 + len(lenstr)) + lenstr + else: + self.content += chr(len(val)) + self.content += val + + def encode(self, x): + if type(x) is bool: + if x: + self.encode_tlv(1, '\xff') + else: + self.encode_tlv(1, '\x00') + elif (type(x) is int) or (type(x) is long): + self.encode_tlv(2, util.deflate_long(x)) + elif type(x) is str: + self.encode_tlv(4, x) + elif (type(x) is list) or (type(x) is tuple): + self.encode_tlv(0x30, self.encode_sequence(x)) + else: + raise BERException('Unknown type for encoding: %s' % repr(type(x))) + + def encode_sequence(data): + b = BER() + for item in data: + b.encode(item) + return str(b) + encode_sequence = staticmethod(encode_sequence) diff --git a/paramiko/channel.py b/paramiko/channel.py new file mode 100644 index 0000000..8a00233 --- /dev/null +++ b/paramiko/channel.py @@ -0,0 +1,1174 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Abstraction for an SSH2 channel. +""" + +import sys +import time +import threading +import socket +import os + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ssh_exception import SSHException +from paramiko.file import BufferedFile +from paramiko import pipe + + +class Channel (object): + """ + A secure tunnel across an SSH L{Transport}. A Channel is meant to behave + like a socket, and has an API that should be indistinguishable from the + python socket API. + + Because SSH2 has a windowing kind of flow control, if you stop reading data + from a Channel and its buffer fills up, the server will be unable to send + you any more data until you read some of it. (This won't affect other + channels on the same transport -- all channels on a single transport are + flow-controlled independently.) Similarly, if the server isn't reading + data you send, calls to L{send} may block, unless you set a timeout. This + is exactly like a normal network socket, so it shouldn't be too surprising. + """ + + # lower bound on the max packet size we'll accept from the remote host + MIN_PACKET_SIZE = 1024 + + def __init__(self, chanid): + """ + Create a new channel. The channel is not associated with any + particular session or L{Transport} until the Transport attaches it. + Normally you would only call this method from the constructor of a + subclass of L{Channel}. + + @param chanid: the ID of this channel, as passed by an existing + L{Transport}. + @type chanid: int + """ + self.chanid = chanid + self.remote_chanid = 0 + self.transport = None + self.active = False + self.eof_received = 0 + self.eof_sent = 0 + self.in_buffer = '' + self.in_stderr_buffer = '' + self.timeout = None + self.closed = False + self.ultra_debug = False + self.lock = threading.Lock() + self.in_buffer_cv = threading.Condition(self.lock) + self.in_stderr_buffer_cv = threading.Condition(self.lock) + self.out_buffer_cv = threading.Condition(self.lock) + self.in_window_size = 0 + self.out_window_size = 0 + self.in_max_packet_size = 0 + self.out_max_packet_size = 0 + self.in_window_threshold = 0 + self.in_window_sofar = 0 + self.status_event = threading.Event() + self.name = str(chanid) + self.logger = util.get_logger('paramiko.chan.' + str(chanid)) + self.pipe = None + self.event = threading.Event() + self.combine_stderr = False + self.exit_status = -1 + + def __del__(self): + self.close() + + def __repr__(self): + """ + Return a string representation of this object, for debugging. + + @rtype: str + """ + out = '<paramiko.Channel %d' % self.chanid + if self.closed: + out += ' (closed)' + elif self.active: + if self.eof_received: + out += ' (EOF received)' + if self.eof_sent: + out += ' (EOF sent)' + out += ' (open) window=%d' % (self.out_window_size) + if len(self.in_buffer) > 0: + out += ' in-buffer=%d' % (len(self.in_buffer),) + out += ' -> ' + repr(self.transport) + out += '>' + return out + + def get_pty(self, term='vt100', width=80, height=24): + """ + Request a pseudo-terminal from the server. This is usually used right + after creating a client channel, to ask the server to provide some + basic terminal semantics for a shell invoked with L{invoke_shell}. + It isn't necessary (or desirable) to call this method if you're going + to exectue a single command with L{exec_command}. + + @param term: the terminal type to emulate (for example, C{'vt100'}). + @type term: str + @param width: width (in characters) of the terminal screen + @type width: int + @param height: height (in characters) of the terminal screen + @type height: int + @return: C{True} if the operation succeeded; C{False} if not. + @rtype: bool + """ + if self.closed or self.eof_received or self.eof_sent or not self.active: + raise SSHException('Channel is not open') + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('pty-req') + m.add_boolean(True) + m.add_string(term) + m.add_int(width) + m.add_int(height) + # pixel height, width (usually useless) + m.add_int(0).add_int(0) + m.add_string('') + self.event.clear() + self.transport._send_user_message(m) + while True: + self.event.wait(0.1) + if self.closed: + return False + if self.event.isSet(): + return True + + def invoke_shell(self): + """ + Request an interactive shell session on this channel. If the server + allows it, the channel will then be directly connected to the stdin, + stdout, and stderr of the shell. + + Normally you would call L{get_pty} before this, in which case the + shell will operate through the pty, and the channel will be connected + to the stdin and stdout of the pty. + + When the shell exits, the channel will be closed and can't be reused. + You must open a new channel if you wish to open another shell. + + @return: C{True} if the operation succeeded; C{False} if not. + @rtype: bool + """ + if self.closed or self.eof_received or self.eof_sent or not self.active: + raise SSHException('Channel is not open') + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('shell') + m.add_boolean(1) + self.event.clear() + self.transport._send_user_message(m) + while True: + self.event.wait(0.1) + if self.closed: + return False + if self.event.isSet(): + return True + + def exec_command(self, command): + """ + Execute a command on the server. If the server allows it, the channel + will then be directly connected to the stdin, stdout, and stderr of + the command being executed. + + When the command finishes executing, the channel will be closed and + can't be reused. You must open a new channel if you wish to execute + another command. + + @param command: a shell command to execute. + @type command: str + @return: C{True} if the operation succeeded; C{False} if not. + @rtype: bool + """ + if self.closed or self.eof_received or self.eof_sent or not self.active: + raise SSHException('Channel is not open') + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('exec') + m.add_boolean(1) + m.add_string(command) + self.event.clear() + self.transport._send_user_message(m) + while True: + self.event.wait(0.1) + if self.closed: + return False + if self.event.isSet(): + return True + + def invoke_subsystem(self, subsystem): + """ + Request a subsystem on the server (for example, C{sftp}). If the + server allows it, the channel will then be directly connected to the + requested subsystem. + + When the subsystem finishes, the channel will be closed and can't be + reused. + + @param subsystem: name of the subsystem being requested. + @type subsystem: str + @return: C{True} if the operation succeeded; C{False} if not. + @rtype: bool + """ + if self.closed or self.eof_received or self.eof_sent or not self.active: + raise SSHException('Channel is not open') + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('subsystem') + m.add_boolean(1) + m.add_string(subsystem) + self.event.clear() + self.transport._send_user_message(m) + while True: + self.event.wait(0.1) + if self.closed: + return False + if self.event.isSet(): + return True + + def resize_pty(self, width=80, height=24): + """ + Resize the pseudo-terminal. This can be used to change the width and + height of the terminal emulation created in a previous L{get_pty} call. + + @param width: new width (in characters) of the terminal screen + @type width: int + @param height: new height (in characters) of the terminal screen + @type height: int + @return: C{True} if the operation succeeded; C{False} if not. + @rtype: bool + """ + if self.closed or self.eof_received or self.eof_sent or not self.active: + raise SSHException('Channel is not open') + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('window-change') + m.add_boolean(1) + m.add_int(width) + m.add_int(height) + m.add_int(0).add_int(0) + self.event.clear() + self.transport._send_user_message(m) + while True: + self.event.wait(0.1) + if self.closed: + return False + if self.event.isSet(): + return True + + def recv_exit_status(self): + """ + Return the exit status from the process on the server. This is + mostly useful for retrieving the reults of an L{exec_command}. + If the command hasn't finished yet, this method will wait until + it does, or until the channel is closed. If no exit status is + provided by the server, -1 is returned. + + @return: the exit code of the process on the server. + @rtype: int + + @since: 1.2 + """ + while True: + if self.closed or self.status_event.isSet(): + return self.exit_status + self.status_event.wait(0.1) + + def send_exit_status(self, status): + """ + Send the exit status of an executed command to the client. (This + really only makes sense in server mode.) Many clients expect to + get some sort of status code back from an executed command after + it completes. + + @param status: the exit code of the process + @type status: int + + @since: 1.2 + """ + # in many cases, the channel will not still be open here. + # that's fine. + m = Message() + m.add_byte(chr(MSG_CHANNEL_REQUEST)) + m.add_int(self.remote_chanid) + m.add_string('exit-status') + m.add_boolean(0) + m.add_int(status) + self.transport._send_user_message(m) + + def get_transport(self): + """ + Return the L{Transport} associated with this channel. + + @return: the L{Transport} that was used to create this channel. + @rtype: L{Transport} + """ + return self.transport + + def set_name(self, name): + """ + Set a name for this channel. Currently it's only used to set the name + of the log level used for debugging. The name can be fetched with the + L{get_name} method. + + @param name: new channel name. + @type name: str + """ + self.name = name + self.logger = util.get_logger(self.transport.get_log_channel() + '.' + self.name) + + def get_name(self): + """ + Get the name of this channel that was previously set by L{set_name}. + + @return: the name of this channel. + @rtype: str + """ + return self.name + + def get_id(self): + """ + Return the ID # for this channel. The channel ID is unique across + a L{Transport} and usually a small number. It's also the number + passed to L{ServerInterface.check_channel_request} when determining + whether to accept a channel request in server mode. + + @return: the ID of this channel. + @rtype: int + + @since: ivysaur + """ + return self.chanid + + def set_combine_stderr(self, combine): + """ + Set whether stderr should be combined into stdout on this channel. + The default is C{False}, but in some cases it may be convenient to + have both streams combined. + + If this is C{False}, and L{exec_command} is called (or C{invoke_shell} + with no pty), output to stderr will not show up through the L{recv} + and L{recv_ready} calls. You will have to use L{recv_stderr} and + L{recv_stderr_ready} to get stderr output. + + If this is C{True}, data will never show up via L{recv_stderr} or + L{recv_stderr_ready}. + + @param combine: C{True} if stderr output should be combined into + stdout on this channel. + @type combine: bool + @return: previous setting. + @rtype: bool + + @since: 1.1 + """ + data = '' + self.lock.acquire() + try: + old = self.combine_stderr + self.combine_stderr = combine + if combine and not old: + # copy old stderr buffer into primary buffer + data = self.in_stderr_buffer + self.in_stderr_buffer = '' + finally: + self.lock.release() + if len(data) > 0: + self._feed(data) + return old + + + ### socket API + + + def settimeout(self, timeout): + """ + Set a timeout on blocking read/write operations. The C{timeout} + argument can be a nonnegative float expressing seconds, or C{None}. If + a float is given, subsequent channel read/write operations will raise + a timeout exception if the timeout period value has elapsed before the + operation has completed. Setting a timeout of C{None} disables + timeouts on socket operations. + + C{chan.settimeout(0.0)} is equivalent to C{chan.setblocking(0)}; + C{chan.settimeout(None)} is equivalent to C{chan.setblocking(1)}. + + @param timeout: seconds to wait for a pending read/write operation + before raising C{socket.timeout}, or C{None} for no timeout. + @type timeout: float + """ + self.timeout = timeout + + def gettimeout(self): + """ + Returns the timeout in seconds (as a float) associated with socket + operations, or C{None} if no timeout is set. This reflects the last + call to L{setblocking} or L{settimeout}. + + @return: timeout in seconds, or C{None}. + @rtype: float + """ + return self.timeout + + def setblocking(self, blocking): + """ + Set blocking or non-blocking mode of the channel: if C{blocking} is 0, + the channel is set to non-blocking mode; otherwise it's set to blocking + mode. Initially all channels are in blocking mode. + + In non-blocking mode, if a L{recv} call doesn't find any data, or if a + L{send} call can't immediately dispose of the data, an error exception + is raised. In blocking mode, the calls block until they can proceed. + + C{chan.setblocking(0)} is equivalent to C{chan.settimeout(0)}; + C{chan.setblocking(1)} is equivalent to C{chan.settimeout(None)}. + + @param blocking: 0 to set non-blocking mode; non-0 to set blocking + mode. + @type blocking: int + """ + if blocking: + self.settimeout(None) + else: + self.settimeout(0.0) + + def close(self): + """ + Close the channel. All future read/write operations on the channel + will fail. The remote end will receive no more data (after queued data + is flushed). Channels are automatically closed when their L{Transport} + is closed or when they are garbage collected. + """ + self.lock.acquire() + try: + if not self.active or self.closed: + return + msgs = self._close_internal() + + # only close the pipe when the user explicitly closes the channel. + # otherwise they will get unpleasant surprises. + if self.pipe is not None: + self.pipe.close() + self.pipe = None + finally: + self.lock.release() + for m in msgs: + if m is not None: + self.transport._send_user_message(m) + + def recv_ready(self): + """ + Returns true if data is buffered and ready to be read from this + channel. A C{False} result does not mean that the channel has closed; + it means you may need to wait before more data arrives. + + @return: C{True} if a L{recv} call on this channel would immediately + return at least one byte; C{False} otherwise. + @rtype: boolean + """ + self.lock.acquire() + try: + if len(self.in_buffer) == 0: + return False + return True + finally: + self.lock.release() + + def recv(self, nbytes): + """ + Receive data from the channel. The return value is a string + representing the data received. The maximum amount of data to be + received at once is specified by C{nbytes}. If a string of length zero + is returned, the channel stream has closed. + + @param nbytes: maximum number of bytes to read. + @type nbytes: int + @return: data. + @rtype: str + + @raise socket.timeout: if no data is ready before the timeout set by + L{settimeout}. + """ + out = '' + self.lock.acquire() + try: + if len(self.in_buffer) == 0: + if self.closed or self.eof_received: + return out + # should we block? + if self.timeout == 0.0: + raise socket.timeout() + # loop here in case we get woken up but a different thread has grabbed everything in the buffer + timeout = self.timeout + while (len(self.in_buffer) == 0) and not self.closed and not self.eof_received: + then = time.time() + self.in_buffer_cv.wait(timeout) + if timeout != None: + timeout -= time.time() - then + if timeout <= 0.0: + raise socket.timeout() + # something in the buffer and we have the lock + if len(self.in_buffer) <= nbytes: + out = self.in_buffer + self.in_buffer = '' + if self.pipe is not None: + # clear the pipe, since no more data is buffered + self.pipe.clear() + else: + out = self.in_buffer[:nbytes] + self.in_buffer = self.in_buffer[nbytes:] + ack = self._check_add_window(len(out)) + finally: + self.lock.release() + + # no need to hold the channel lock when sending this + if ack > 0: + m = Message() + m.add_byte(chr(MSG_CHANNEL_WINDOW_ADJUST)) + m.add_int(self.remote_chanid) + m.add_int(ack) + self.transport._send_user_message(m) + + return out + + def recv_stderr_ready(self): + """ + Returns true if data is buffered and ready to be read from this + channel's stderr stream. Only channels using L{exec_command} or + L{invoke_shell} without a pty will ever have data on the stderr + stream. + + @return: C{True} if a L{recv_stderr} call on this channel would + immediately return at least one byte; C{False} otherwise. + @rtype: boolean + + @since: 1.1 + """ + self.lock.acquire() + try: + if len(self.in_stderr_buffer) == 0: + return False + return True + finally: + self.lock.release() + + def recv_stderr(self, nbytes): + """ + Receive data from the channel's stderr stream. Only channels using + L{exec_command} or L{invoke_shell} without a pty will ever have data + on the stderr stream. The return value is a string representing the + data received. The maximum amount of data to be received at once is + specified by C{nbytes}. If a string of length zero is returned, the + channel stream has closed. + + @param nbytes: maximum number of bytes to read. + @type nbytes: int + @return: data. + @rtype: str + + @raise socket.timeout: if no data is ready before the timeout set by + L{settimeout}. + + @since: 1.1 + """ + out = '' + self.lock.acquire() + try: + if len(self.in_stderr_buffer) == 0: + if self.closed or self.eof_received: + return out + # should we block? + if self.timeout == 0.0: + raise socket.timeout() + # loop here in case we get woken up but a different thread has grabbed everything in the buffer + timeout = self.timeout + while (len(self.in_stderr_buffer) == 0) and not self.closed and not self.eof_received: + then = time.time() + self.in_stderr_buffer_cv.wait(timeout) + if timeout != None: + timeout -= time.time() - then + if timeout <= 0.0: + raise socket.timeout() + # something in the buffer and we have the lock + if len(self.in_stderr_buffer) <= nbytes: + out = self.in_stderr_buffer + self.in_stderr_buffer = '' + else: + out = self.in_stderr_buffer[:nbytes] + self.in_stderr_buffer = self.in_stderr_buffer[nbytes:] + self._check_add_window(len(out)) + finally: + self.lock.release() + return out + + def send(self, s): + """ + Send data to the channel. Returns the number of bytes sent, or 0 if + the channel stream is closed. Applications are responsible for + checking that all data has been sent: if only some of the data was + transmitted, the application needs to attempt delivery of the remaining + data. + + @param s: data to send. + @type s: str + @return: number of bytes actually sent. + @rtype: int + + @raise socket.timeout: if no data could be sent before the timeout set + by L{settimeout}. + """ + size = len(s) + self.lock.acquire() + try: + size = self._wait_for_send_window(size) + if size == 0: + # eof or similar + return 0 + m = Message() + m.add_byte(chr(MSG_CHANNEL_DATA)) + m.add_int(self.remote_chanid) + m.add_string(s[:size]) + self.transport._send_user_message(m) + finally: + self.lock.release() + return size + + def send_stderr(self, s): + """ + Send data to the channel on the "stderr" stream. This is normally + only used by servers to send output from shell commands -- clients + won't use this. Returns the number of bytes sent, or 0 if the channel + stream is closed. Applications are responsible for checking that all + data has been sent: if only some of the data was transmitted, the + application needs to attempt delivery of the remaining data. + + @param s: data to send. + @type s: str + @return: number of bytes actually sent. + @rtype: int + + @raise socket.timeout: if no data could be sent before the timeout set + by L{settimeout}. + + @since: 1.1 + """ + size = len(s) + self.lock.acquire() + try: + size = self._wait_for_send_window(size) + if size == 0: + # eof or similar + return 0 + m = Message() + m.add_byte(chr(MSG_CHANNEL_EXTENDED_DATA)) + m.add_int(self.remote_chanid) + m.add_int(1) + m.add_string(s[:size]) + self.transport._send_user_message(m) + finally: + self.lock.release() + return size + + def sendall(self, s): + """ + Send data to the channel, without allowing partial results. Unlike + L{send}, this method continues to send data from the given string until + either all data has been sent or an error occurs. Nothing is returned. + + @param s: data to send. + @type s: str + + @raise socket.timeout: if sending stalled for longer than the timeout + set by L{settimeout}. + @raise socket.error: if an error occured before the entire string was + sent. + + @note: If the channel is closed while only part of the data hase been + sent, there is no way to determine how much data (if any) was sent. + This is irritating, but identically follows python's API. + """ + while s: + if self.closed: + # this doesn't seem useful, but it is the documented behavior of Socket + raise socket.error('Socket is closed') + sent = self.send(s) + s = s[sent:] + return None + + def sendall_stderr(self, s): + """ + Send data to the channel's "stderr" stream, without allowing partial + results. Unlike L{send_stderr}, this method continues to send data + from the given string until all data has been sent or an error occurs. + Nothing is returned. + + @param s: data to send to the client as "stderr" output. + @type s: str + + @raise socket.timeout: if sending stalled for longer than the timeout + set by L{settimeout}. + @raise socket.error: if an error occured before the entire string was + sent. + + @since: 1.1 + """ + while s: + if self.closed: + raise socket.error('Socket is closed') + sent = self.send_stderr(s) + s = s[sent:] + return None + + def makefile(self, *params): + """ + Return a file-like object associated with this channel. The optional + C{mode} and C{bufsize} arguments are interpreted the same way as by + the built-in C{file()} function in python. + + @return: object which can be used for python file I/O. + @rtype: L{ChannelFile} + """ + return ChannelFile(*([self] + list(params))) + + def makefile_stderr(self, *params): + """ + Return a file-like object associated with this channel's stderr + stream. Only channels using L{exec_command} or L{invoke_shell} + without a pty will ever have data on the stderr stream. + + The optional C{mode} and C{bufsize} arguments are interpreted the + same way as by the built-in C{file()} function in python. For a + client, it only makes sense to open this file for reading. For a + server, it only makes sense to open this file for writing. + + @return: object which can be used for python file I/O. + @rtype: L{ChannelFile} + + @since: 1.1 + """ + return ChannelStderrFile(*([self] + list(params))) + + def fileno(self): + """ + Returns an OS-level file descriptor which can be used for polling, but + but I{not} for reading or writing). This is primaily to allow python's + C{select} module to work. + + The first time C{fileno} is called on a channel, a pipe is created to + simulate real OS-level file descriptor (FD) behavior. Because of this, + two OS-level FDs are created, which will use up FDs faster than normal. + You won't notice this effect unless you open hundreds or thousands of + channels simultaneously, but it's still notable. + + @return: an OS-level file descriptor + @rtype: int + + @warning: This method causes channel reads to be slightly less + efficient. + """ + self.lock.acquire() + try: + if self.pipe is not None: + return self.pipe.fileno() + # create the pipe and feed in any existing data + self.pipe = pipe.make_pipe() + if len(self.in_buffer) > 0: + self.pipe.set() + return self.pipe.fileno() + finally: + self.lock.release() + + def shutdown(self, how): + """ + Shut down one or both halves of the connection. If C{how} is 0, + further receives are disallowed. If C{how} is 1, further sends + are disallowed. If C{how} is 2, further sends and receives are + disallowed. This closes the stream in one or both directions. + + @param how: 0 (stop receiving), 1 (stop sending), or 2 (stop + receiving and sending). + @type how: int + """ + if (how == 0) or (how == 2): + # feign "read" shutdown + self.eof_received = 1 + if (how == 1) or (how == 2): + self.lock.acquire() + try: + m = self._send_eof() + finally: + self.lock.release() + if m is not None: + self.transport._send_user_message(m) + + def shutdown_read(self): + """ + Shutdown the receiving side of this socket, closing the stream in + the incoming direction. After this call, future reads on this + channel will fail instantly. This is a convenience method, equivalent + to C{shutdown(0)}, for people who don't make it a habit to + memorize unix constants from the 1970s. + + @since: 1.2 + """ + self.shutdown(0) + + def shutdown_write(self): + """ + Shutdown the sending side of this socket, closing the stream in + the outgoing direction. After this call, future writes on this + channel will fail instantly. This is a convenience method, equivalent + to C{shutdown(1)}, for people who don't make it a habit to + memorize unix constants from the 1970s. + + @since: 1.2 + """ + self.shutdown(1) + + + ### calls from Transport + + + def _set_transport(self, transport): + self.transport = transport + self.logger = util.get_logger(self.transport.get_log_channel() + '.' + self.name) + + def _set_window(self, window_size, max_packet_size): + self.in_window_size = window_size + self.in_max_packet_size = max_packet_size + # threshold of bytes we receive before we bother to send a window update + self.in_window_threshold = window_size // 10 + self.in_window_sofar = 0 + self._log(DEBUG, 'Max packet in: %d bytes' % max_packet_size) + + def _set_remote_channel(self, chanid, window_size, max_packet_size): + self.remote_chanid = chanid + self.out_window_size = window_size + self.out_max_packet_size = max(max_packet_size, self.MIN_PACKET_SIZE) + self.active = 1 + self._log(DEBUG, 'Max packet out: %d bytes' % max_packet_size) + + def _request_success(self, m): + self._log(DEBUG, 'Sesch channel %d request ok' % self.chanid) + self.event.set() + return + + def _request_failed(self, m): + self.lock.acquire() + try: + msgs = self._close_internal() + finally: + self.lock.release() + for m in msgs: + if m is not None: + self.transport._send_user_message(m) + + def _feed(self, m): + if type(m) is str: + # passed from _feed_extended + s = m + else: + s = m.get_string() + self.lock.acquire() + try: + if self.ultra_debug: + self._log(DEBUG, 'fed %d bytes' % len(s)) + if self.pipe is not None: + self.pipe.set() + self.in_buffer += s + self.in_buffer_cv.notifyAll() + finally: + self.lock.release() + + def _feed_extended(self, m): + code = m.get_int() + s = m.get_string() + if code != 1: + self._log(ERROR, 'unknown extended_data type %d; discarding' % code) + return + if self.combine_stderr: + return self._feed(s) + self.lock.acquire() + try: + if self.ultra_debug: + self._log(DEBUG, 'fed %d stderr bytes' % len(s)) + self.in_stderr_buffer += s + self.in_stderr_buffer_cv.notifyAll() + finally: + self.lock.release() + + def _window_adjust(self, m): + nbytes = m.get_int() + self.lock.acquire() + try: + if self.ultra_debug: + self._log(DEBUG, 'window up %d' % nbytes) + self.out_window_size += nbytes + self.out_buffer_cv.notifyAll() + finally: + self.lock.release() + + def _handle_request(self, m): + key = m.get_string() + want_reply = m.get_boolean() + server = self.transport.server_object + ok = False + if key == 'exit-status': + self.exit_status = m.get_int() + self.status_event.set() + ok = True + elif key == 'xon-xoff': + # ignore + ok = True + elif key == 'pty-req': + term = m.get_string() + width = m.get_int() + height = m.get_int() + pixelwidth = m.get_int() + pixelheight = m.get_int() + modes = m.get_string() + if server is None: + ok = False + else: + ok = server.check_channel_pty_request(self, term, width, height, pixelwidth, + pixelheight, modes) + elif key == 'shell': + if server is None: + ok = False + else: + ok = server.check_channel_shell_request(self) + elif key == 'exec': + cmd = m.get_string() + if server is None: + ok = False + else: + ok = server.check_channel_exec_request(self, cmd) + elif key == 'subsystem': + name = m.get_string() + if server is None: + ok = False + else: + ok = server.check_channel_subsystem_request(self, name) + elif key == 'window-change': + width = m.get_int() + height = m.get_int() + pixelwidth = m.get_int() + pixelheight = m.get_int() + if server is None: + ok = False + else: + ok = server.check_channel_window_change_request(self, width, height, pixelwidth, + pixelheight) + else: + self._log(DEBUG, 'Unhandled channel request "%s"' % key) + ok = False + if want_reply: + m = Message() + if ok: + m.add_byte(chr(MSG_CHANNEL_SUCCESS)) + else: + m.add_byte(chr(MSG_CHANNEL_FAILURE)) + m.add_int(self.remote_chanid) + self.transport._send_user_message(m) + + def _handle_eof(self, m): + self.lock.acquire() + try: + if not self.eof_received: + self.eof_received = True + self.in_buffer_cv.notifyAll() + self.in_stderr_buffer_cv.notifyAll() + if self.pipe is not None: + self.pipe.set_forever() + finally: + self.lock.release() + self._log(DEBUG, 'EOF received') + + def _handle_close(self, m): + self.lock.acquire() + try: + msgs = self._close_internal() + self.transport._unlink_channel(self.chanid) + finally: + self.lock.release() + for m in msgs: + if m is not None: + self.transport._send_user_message(m) + + + ### internals... + + + def _log(self, level, msg): + self.logger.log(level, msg) + + def _set_closed(self): + # you are holding the lock. + self.closed = True + self.in_buffer_cv.notifyAll() + self.in_stderr_buffer_cv.notifyAll() + self.out_buffer_cv.notifyAll() + if self.pipe is not None: + self.pipe.set_forever() + + def _send_eof(self): + # you are holding the lock. + if self.eof_sent: + return None + m = Message() + m.add_byte(chr(MSG_CHANNEL_EOF)) + m.add_int(self.remote_chanid) + self.eof_sent = True + self._log(DEBUG, 'EOF sent') + return m + + def _close_internal(self): + # you are holding the lock. + if not self.active or self.closed: + return None, None + m1 = self._send_eof() + m2 = Message() + m2.add_byte(chr(MSG_CHANNEL_CLOSE)) + m2.add_int(self.remote_chanid) + self._set_closed() + # can't unlink from the Transport yet -- the remote side may still + # try to send meta-data (exit-status, etc) + return m1, m2 + + def _unlink(self): + # server connection could die before we become active: still signal the close! + if self.closed: + return + self.lock.acquire() + try: + self._set_closed() + self.transport._unlink_channel(self.chanid) + finally: + self.lock.release() + + def _check_add_window(self, n): + # already holding the lock! + if self.closed or self.eof_received or not self.active: + return 0 + if self.ultra_debug: + self._log(DEBUG, 'addwindow %d' % n) + self.in_window_sofar += n + if self.in_window_sofar <= self.in_window_threshold: + return 0 + if self.ultra_debug: + self._log(DEBUG, 'addwindow send %d' % self.in_window_sofar) + out = self.in_window_sofar + self.in_window_sofar = 0 + return out + + def _wait_for_send_window(self, size): + """ + (You are already holding the lock.) + Wait for the send window to open up, and allocate up to C{size} bytes + for transmission. If no space opens up before the timeout, a timeout + exception is raised. Returns the number of bytes available to send + (may be less than requested). + """ + # you are already holding the lock + if self.closed or self.eof_sent: + return 0 + if self.out_window_size == 0: + # should we block? + if self.timeout == 0.0: + raise socket.timeout() + # loop here in case we get woken up but a different thread has filled the buffer + timeout = self.timeout + while self.out_window_size == 0: + if self.closed or self.eof_sent: + return 0 + then = time.time() + self.out_buffer_cv.wait(timeout) + if timeout != None: + timeout -= time.time() - then + if timeout <= 0.0: + raise socket.timeout() + # we have some window to squeeze into + if self.closed or self.eof_sent: + return 0 + if self.out_window_size < size: + size = self.out_window_size + if self.out_max_packet_size - 64 < size: + size = self.out_max_packet_size - 64 + self.out_window_size -= size + if self.ultra_debug: + self._log(DEBUG, 'window down to %d' % self.out_window_size) + return size + + +class ChannelFile (BufferedFile): + """ + A file-like wrapper around L{Channel}. A ChannelFile is created by calling + L{Channel.makefile}. + + @bug: To correctly emulate the file object created from a socket's + C{makefile} method, a L{Channel} and its C{ChannelFile} should be able + to be closed or garbage-collected independently. Currently, closing + the C{ChannelFile} does nothing but flush the buffer. + """ + + def __init__(self, channel, mode = 'r', bufsize = -1): + self.channel = channel + BufferedFile.__init__(self) + self._set_mode(mode, bufsize) + + def __repr__(self): + """ + Returns a string representation of this object, for debugging. + + @rtype: str + """ + return '<paramiko.ChannelFile from ' + repr(self.channel) + '>' + + def _read(self, size): + return self.channel.recv(size) + + def _write(self, data): + self.channel.sendall(data) + return len(data) + + seek = BufferedFile.seek + + +class ChannelStderrFile (ChannelFile): + def __init__(self, channel, mode = 'r', bufsize = -1): + ChannelFile.__init__(self, channel, mode, bufsize) + + def _read(self, size): + return self.channel.recv_stderr(size) + + def _write(self, data): + self.channel.sendall_stderr(data) + return len(data) + + +# vim: set shiftwidth=4 expandtab : diff --git a/paramiko/common.py b/paramiko/common.py new file mode 100644 index 0000000..c5999e6 --- /dev/null +++ b/paramiko/common.py @@ -0,0 +1,136 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Common constants and global variables. +""" + +MSG_DISCONNECT, MSG_IGNORE, MSG_UNIMPLEMENTED, MSG_DEBUG, MSG_SERVICE_REQUEST, \ + MSG_SERVICE_ACCEPT = range(1, 7) +MSG_KEXINIT, MSG_NEWKEYS = range(20, 22) +MSG_USERAUTH_REQUEST, MSG_USERAUTH_FAILURE, MSG_USERAUTH_SUCCESS, \ + MSG_USERAUTH_BANNER = range(50, 54) +MSG_USERAUTH_PK_OK = 60 +MSG_USERAUTH_INFO_REQUEST, MSG_USERAUTH_INFO_RESPONSE = range(60, 62) +MSG_GLOBAL_REQUEST, MSG_REQUEST_SUCCESS, MSG_REQUEST_FAILURE = range(80, 83) +MSG_CHANNEL_OPEN, MSG_CHANNEL_OPEN_SUCCESS, MSG_CHANNEL_OPEN_FAILURE, \ + MSG_CHANNEL_WINDOW_ADJUST, MSG_CHANNEL_DATA, MSG_CHANNEL_EXTENDED_DATA, \ + MSG_CHANNEL_EOF, MSG_CHANNEL_CLOSE, MSG_CHANNEL_REQUEST, \ + MSG_CHANNEL_SUCCESS, MSG_CHANNEL_FAILURE = range(90, 101) + + +# for debugging: +MSG_NAMES = { + MSG_DISCONNECT: 'disconnect', + MSG_IGNORE: 'ignore', + MSG_UNIMPLEMENTED: 'unimplemented', + MSG_DEBUG: 'debug', + MSG_SERVICE_REQUEST: 'service-request', + MSG_SERVICE_ACCEPT: 'service-accept', + MSG_KEXINIT: 'kexinit', + MSG_NEWKEYS: 'newkeys', + 30: 'kex30', + 31: 'kex31', + 32: 'kex32', + 33: 'kex33', + 34: 'kex34', + MSG_USERAUTH_REQUEST: 'userauth-request', + MSG_USERAUTH_FAILURE: 'userauth-failure', + MSG_USERAUTH_SUCCESS: 'userauth-success', + MSG_USERAUTH_BANNER: 'userauth--banner', + MSG_USERAUTH_PK_OK: 'userauth-60(pk-ok/info-request)', + MSG_USERAUTH_INFO_RESPONSE: 'userauth-info-response', + MSG_GLOBAL_REQUEST: 'global-request', + MSG_REQUEST_SUCCESS: 'request-success', + MSG_REQUEST_FAILURE: 'request-failure', + MSG_CHANNEL_OPEN: 'channel-open', + MSG_CHANNEL_OPEN_SUCCESS: 'channel-open-success', + MSG_CHANNEL_OPEN_FAILURE: 'channel-open-failure', + MSG_CHANNEL_WINDOW_ADJUST: 'channel-window-adjust', + MSG_CHANNEL_DATA: 'channel-data', + MSG_CHANNEL_EXTENDED_DATA: 'channel-extended-data', + MSG_CHANNEL_EOF: 'channel-eof', + MSG_CHANNEL_CLOSE: 'channel-close', + MSG_CHANNEL_REQUEST: 'channel-request', + MSG_CHANNEL_SUCCESS: 'channel-success', + MSG_CHANNEL_FAILURE: 'channel-failure' + } + + +# authentication request return codes: +AUTH_SUCCESSFUL, AUTH_PARTIALLY_SUCCESSFUL, AUTH_FAILED = range(3) + + +# channel request failed reasons: +(OPEN_SUCCEEDED, + OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED, + OPEN_FAILED_CONNECT_FAILED, + OPEN_FAILED_UNKNOWN_CHANNEL_TYPE, + OPEN_FAILED_RESOURCE_SHORTAGE) = range(0, 5) + + +CONNECTION_FAILED_CODE = { + 1: 'Administratively prohibited', + 2: 'Connect failed', + 3: 'Unknown channel type', + 4: 'Resource shortage' +} + + +DISCONNECT_SERVICE_NOT_AVAILABLE, DISCONNECT_AUTH_CANCELLED_BY_USER, \ + DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE = 7, 13, 14 + + +from Crypto.Util.randpool import PersistentRandomPool, RandomPool + +# keep a crypto-strong PRNG nearby +try: + randpool = PersistentRandomPool(os.path.join(os.path.expanduser('~'), '/.randpool')) +except: + # the above will likely fail on Windows - fall back to non-persistent random pool + randpool = RandomPool() + +try: + randpool.randomize() +except: + # earlier versions of pyCrypto (pre-2.0) don't have randomize() + pass + +import sys +if sys.version_info < (2, 3): + try: + import logging + except: + import logging22 as logging + import select + PY22 = True + + import socket + if not hasattr(socket, 'timeout'): + class timeout(socket.error): pass + socket.timeout = timeout + del timeout +else: + import logging + PY22 = False + +DEBUG = logging.DEBUG +INFO = logging.INFO +WARNING = logging.WARNING +ERROR = logging.ERROR +CRITICAL = logging.CRITICAL diff --git a/paramiko/compress.py b/paramiko/compress.py new file mode 100644 index 0000000..bdf4b42 --- /dev/null +++ b/paramiko/compress.py @@ -0,0 +1,39 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Compression implementations for a Transport. +""" + +import zlib + + +class ZlibCompressor (object): + def __init__(self): + self.z = zlib.compressobj(9) + + def __call__(self, data): + return self.z.compress(data) + self.z.flush(zlib.Z_FULL_FLUSH) + + +class ZlibDecompressor (object): + def __init__(self): + self.z = zlib.decompressobj() + + def __call__(self, data): + return self.z.decompress(data) diff --git a/paramiko/dsskey.py b/paramiko/dsskey.py new file mode 100644 index 0000000..2b31372 --- /dev/null +++ b/paramiko/dsskey.py @@ -0,0 +1,176 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{DSSKey} +""" + +from Crypto.PublicKey import DSA +from Crypto.Hash import SHA + +from paramiko.common import * +from paramiko import util +from paramiko.ssh_exception import SSHException +from paramiko.message import Message +from paramiko.ber import BER, BERException +from paramiko.pkey import PKey + + +class DSSKey (PKey): + """ + Representation of a DSS key which can be used to sign an verify SSH2 + data. + """ + + def __init__(self, msg=None, data=None, filename=None, password=None, vals=None): + if filename is not None: + self._from_private_key_file(filename, password) + return + if (msg is None) and (data is not None): + msg = Message(data) + if vals is not None: + self.p, self.q, self.g, self.y = vals + else: + if msg is None: + raise SSHException('Key object may not be empty') + if msg.get_string() != 'ssh-dss': + raise SSHException('Invalid key') + self.p = msg.get_mpint() + self.q = msg.get_mpint() + self.g = msg.get_mpint() + self.y = msg.get_mpint() + self.size = util.bit_length(self.p) + + def __str__(self): + m = Message() + m.add_string('ssh-dss') + m.add_mpint(self.p) + m.add_mpint(self.q) + m.add_mpint(self.g) + m.add_mpint(self.y) + return str(m) + + def __hash__(self): + h = hash(self.get_name()) + h = h * 37 + hash(self.p) + h = h * 37 + hash(self.q) + h = h * 37 + hash(self.g) + h = h * 37 + hash(self.y) + # h might be a long by now... + return hash(h) + + def get_name(self): + return 'ssh-dss' + + def get_bits(self): + return self.size + + def can_sign(self): + return hasattr(self, 'x') + + def sign_ssh_data(self, rpool, data): + digest = SHA.new(data).digest() + dss = DSA.construct((long(self.y), long(self.g), long(self.p), long(self.q), long(self.x))) + # generate a suitable k + qsize = len(util.deflate_long(self.q, 0)) + while True: + k = util.inflate_long(rpool.get_bytes(qsize), 1) + if (k > 2) and (k < self.q): + break + r, s = dss.sign(util.inflate_long(digest, 1), k) + m = Message() + m.add_string('ssh-dss') + # apparently, in rare cases, r or s may be shorter than 20 bytes! + rstr = util.deflate_long(r, 0) + sstr = util.deflate_long(s, 0) + if len(rstr) < 20: + rstr = '\x00' * (20 - len(rstr)) + rstr + if len(sstr) < 20: + sstr = '\x00' * (20 - len(sstr)) + sstr + m.add_string(rstr + sstr) + return m + + def verify_ssh_sig(self, data, msg): + if len(str(msg)) == 40: + # spies.com bug: signature has no header + sig = str(msg) + else: + kind = msg.get_string() + if kind != 'ssh-dss': + return 0 + sig = msg.get_string() + + # pull out (r, s) which are NOT encoded as mpints + sigR = util.inflate_long(sig[:20], 1) + sigS = util.inflate_long(sig[20:], 1) + sigM = util.inflate_long(SHA.new(data).digest(), 1) + + dss = DSA.construct((long(self.y), long(self.g), long(self.p), long(self.q))) + return dss.verify(sigM, (sigR, sigS)) + + def write_private_key_file(self, filename, password=None): + keylist = [ 0, self.p, self.q, self.g, self.y, self.x ] + try: + b = BER() + b.encode(keylist) + except BERException: + raise SSHException('Unable to create ber encoding of key') + self._write_private_key_file('DSA', filename, str(b), password) + + def generate(bits=1024, progress_func=None): + """ + Generate a new private DSS key. This factory function can be used to + generate a new host key or authentication key. + + @param bits: number of bits the generated key should be. + @type bits: int + @param progress_func: an optional function to call at key points in + key generation (used by C{pyCrypto.PublicKey}). + @type progress_func: function + @return: new private key + @rtype: L{DSSKey} + + @since: fearow + """ + randpool.stir() + dsa = DSA.generate(bits, randpool.get_bytes, progress_func) + key = DSSKey(vals=(dsa.p, dsa.q, dsa.g, dsa.y)) + key.x = dsa.x + return key + generate = staticmethod(generate) + + + ### internals... + + + def _from_private_key_file(self, filename, password): + # private key file contains: + # DSAPrivateKey = { version = 0, p, q, g, y, x } + data = self._read_private_key_file('DSA', filename, password) + try: + keylist = BER(data).decode() + except BERException, x: + raise SSHException('Unable to parse key file: ' + str(x)) + if (type(keylist) is not list) or (len(keylist) < 6) or (keylist[0] != 0): + raise SSHException('not a valid DSA private key file (bad ber encoding)') + self.p = keylist[1] + self.q = keylist[2] + self.g = keylist[3] + self.y = keylist[4] + self.x = keylist[5] + self.size = util.bit_length(self.p) diff --git a/paramiko/file.py b/paramiko/file.py new file mode 100644 index 0000000..c29e7c4 --- /dev/null +++ b/paramiko/file.py @@ -0,0 +1,440 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +BufferedFile. +""" + +from cStringIO import StringIO + + +_FLAG_READ = 0x1 +_FLAG_WRITE = 0x2 +_FLAG_APPEND = 0x4 +_FLAG_BINARY = 0x10 +_FLAG_BUFFERED = 0x20 +_FLAG_LINE_BUFFERED = 0x40 +_FLAG_UNIVERSAL_NEWLINE = 0x80 + + +class BufferedFile (object): + """ + Reusable base class to implement python-style file buffering around a + simpler stream. + """ + + _DEFAULT_BUFSIZE = 8192 + + SEEK_SET = 0 + SEEK_CUR = 1 + SEEK_END = 2 + + def __init__(self): + self._flags = 0 + self._bufsize = self._DEFAULT_BUFSIZE + self._wbuffer = StringIO() + self._rbuffer = '' + self._at_trailing_cr = False + self._closed = False + # pos - position within the file, according to the user + # realpos - position according the OS + # (these may be different because we buffer for line reading) + self._pos = self._realpos = 0 + + def __del__(self): + self.close() + + def __iter__(self): + """ + Returns an iterator that can be used to iterate over the lines in this + file. This iterator happens to return the file itself, since a file is + its own iterator. + + @raise ValueError: if the file is closed. + + @return: an interator. + @rtype: iterator + """ + if self._closed: + raise ValueError('I/O operation on closed file') + return self + + def close(self): + """ + Close the file. Future read and write operations will fail. + """ + self.flush() + self._closed = True + + def flush(self): + """ + Write out any data in the write buffer. This may do nothing if write + buffering is not turned on. + """ + self._write_all(self._wbuffer.getvalue()) + self._wbuffer = StringIO() + return + + def next(self): + """ + Returns the next line from the input, or raises L{StopIteration} when + EOF is hit. Unlike python file objects, it's okay to mix calls to + C{next} and L{readline}. + + @raise StopIteration: when the end of the file is reached. + + @return: a line read from the file. + @rtype: str + """ + line = self.readline() + if not line: + raise StopIteration + return line + + def read(self, size=None): + """ + Read at most C{size} bytes from the file (less if we hit the end of the + file first). If the C{size} argument is negative or omitted, read all + the remaining data in the file. + + @param size: maximum number of bytes to read. + @type size: int + @return: data read from the file, or an empty string if EOF was + encountered immediately. + @rtype: str + """ + if self._closed: + raise IOError('File is closed') + if not (self._flags & _FLAG_READ): + raise IOError('File not open for reading') + if (size is None) or (size < 0): + # go for broke + result = self._rbuffer + self._rbuffer = '' + self._pos += len(result) + while True: + try: + new_data = self._read(self._DEFAULT_BUFSIZE) + except EOFError: + new_data = None + if (new_data is None) or (len(new_data) == 0): + break + result += new_data + self._realpos += len(new_data) + self._pos += len(new_data) + return result + if size <= len(self._rbuffer): + result = self._rbuffer[:size] + self._rbuffer = self._rbuffer[size:] + self._pos += len(result) + return result + while len(self._rbuffer) < size: + try: + new_data = self._read(max(self._bufsize, size - len(self._rbuffer))) + except EOFError: + new_data = None + if (new_data is None) or (len(new_data) == 0): + break + self._rbuffer += new_data + self._realpos += len(new_data) + result = self._rbuffer[:size] + self._rbuffer = self._rbuffer[size:] + self._pos += len(result) + return result + + def readline(self, size=None): + """ + Read one entire line from the file. A trailing newline character is + kept in the string (but may be absent when a file ends with an + incomplete line). If the size argument is present and non-negative, it + is a maximum byte count (including the trailing newline) and an + incomplete line may be returned. An empty string is returned only when + EOF is encountered immediately. + + @note: Unlike stdio's C{fgets()}, the returned string contains null + characters (C{'\\0'}) if they occurred in the input. + + @param size: maximum length of returned string. + @type size: int + @return: next line of the file, or an empty string if the end of the + file has been reached. + @rtype: str + """ + # it's almost silly how complex this function is. + if self._closed: + raise IOError('File is closed') + if not (self._flags & _FLAG_READ): + raise IOError('File not open for reading') + line = self._rbuffer + while True: + if self._at_trailing_cr and (self._flags & _FLAG_UNIVERSAL_NEWLINE) and (len(line) > 0): + # edge case: the newline may be '\r\n' and we may have read + # only the first '\r' last time. + if line[0] == '\n': + line = line[1:] + self._record_newline('\r\n') + else: + self._record_newline('\r') + self._at_trailing_cr = False + # check size before looking for a linefeed, in case we already have + # enough. + if (size is not None) and (size >= 0): + if len(line) >= size: + # truncate line and return + self._rbuffer = line[size:] + line = line[:size] + self._pos += len(line) + return line + n = size - len(line) + else: + n = self._DEFAULT_BUFSIZE + if ('\n' in line) or ((self._flags & _FLAG_UNIVERSAL_NEWLINE) and ('\r' in line)): + break + try: + new_data = self._read(n) + except EOFError: + new_data = None + if (new_data is None) or (len(new_data) == 0): + self._rbuffer = '' + self._pos += len(line) + return line + line += new_data + self._realpos += len(new_data) + # find the newline + pos = line.find('\n') + if self._flags & _FLAG_UNIVERSAL_NEWLINE: + rpos = line.find('\r') + if (rpos >= 0) and ((rpos < pos) or (pos < 0)): + pos = rpos + xpos = pos + 1 + if (line[pos] == '\r') and (xpos < len(line)) and (line[xpos] == '\n'): + xpos += 1 + self._rbuffer = line[xpos:] + lf = line[pos:xpos] + line = line[:pos] + '\n' + if (len(self._rbuffer) == 0) and (lf == '\r'): + # we could read the line up to a '\r' and there could still be a + # '\n' following that we read next time. note that and eat it. + self._at_trailing_cr = True + else: + self._record_newline(lf) + self._pos += len(line) + return line + + def readlines(self, sizehint=None): + """ + Read all remaining lines using L{readline} and return them as a list. + If the optional C{sizehint} argument is present, instead of reading up + to EOF, whole lines totalling approximately sizehint bytes (possibly + after rounding up to an internal buffer size) are read. + + @param sizehint: desired maximum number of bytes to read. + @type sizehint: int + @return: list of lines read from the file. + @rtype: list + """ + lines = [] + bytes = 0 + while 1: + line = self.readline() + if len(line) == 0: + break + lines.append(line) + bytes += len(line) + if (sizehint is not None) and (bytes >= sizehint): + break + return lines + + def seek(self, offset, whence=0): + """ + Set the file's current position, like stdio's C{fseek}. Not all file + objects support seeking. + + @note: If a file is opened in append mode (C{'a'} or C{'a+'}), any seek + operations will be undone at the next write (as the file position + will move back to the end of the file). + + @param offset: position to move to within the file, relative to + C{whence}. + @type offset: int + @param whence: type of movement: 0 = absolute; 1 = relative to the + current position; 2 = relative to the end of the file. + @type whence: int + + @raise IOError: if the file doesn't support random access. + """ + raise IOError('File does not support seeking.') + + def tell(self): + """ + Return the file's current position. This may not be accurate or + useful if the underlying file doesn't support random access, or was + opened in append mode. + + @return: file position (in bytes). + @rtype: int + """ + return self._pos + + def write(self, data): + """ + Write data to the file. If write buffering is on (C{bufsize} was + specified and non-zero), some or all of the data may not actually be + written yet. (Use L{flush} or L{close} to force buffered data to be + written out.) + + @param data: data to write. + @type data: str + """ + if self._closed: + raise IOError('File is closed') + if not (self._flags & _FLAG_WRITE): + raise IOError('File not open for writing') + if not (self._flags & _FLAG_BUFFERED): + self._write_all(data) + return + self._wbuffer.write(data) + if self._flags & _FLAG_LINE_BUFFERED: + # only scan the new data for linefeed, to avoid wasting time. + last_newline_pos = data.rfind('\n') + if last_newline_pos >= 0: + wbuf = self._wbuffer.getvalue() + last_newline_pos += len(wbuf) - len(data) + self._write_all(wbuf[:last_newline_pos + 1]) + self._wbuffer = StringIO() + self._wbuffer.write(wbuf[last_newline_pos + 1:]) + return + # even if we're line buffering, if the buffer has grown past the + # buffer size, force a flush. + if self._wbuffer.tell() >= self._bufsize: + self.flush() + return + + def writelines(self, sequence): + """ + Write a sequence of strings to the file. The sequence can be any + iterable object producing strings, typically a list of strings. (The + name is intended to match L{readlines}; C{writelines} does not add line + separators.) + + @param sequence: an iterable sequence of strings. + @type sequence: sequence + """ + for line in sequence: + self.write(line) + return + + def xreadlines(self): + """ + Identical to C{iter(f)}. This is a deprecated file interface that + predates python iterator support. + + @return: an iterator. + @rtype: iterator + """ + return self + + + ### overrides... + + + def _read(self, size): + """ + I{(subclass override)} + Read data from the stream. Return C{None} or raise C{EOFError} to + indicate EOF. + """ + raise EOFError() + + def _write(self, data): + """ + I{(subclass override)} + Write data into the stream. + """ + raise IOError('write not implemented') + + def _get_size(self): + """ + I{(subclass override)} + Return the size of the file. This is called from within L{_set_mode} + if the file is opened in append mode, so the file position can be + tracked and L{seek} and L{tell} will work correctly. If the file is + a stream that can't be randomly accessed, you don't need to override + this method, + """ + return 0 + + + ### internals... + + + def _set_mode(self, mode='r', bufsize=-1): + """ + Subclasses call this method to initialize the BufferedFile. + """ + if bufsize == 1: + # apparently, line buffering only affects writes. reads are only + # buffered if you call readline (directly or indirectly: iterating + # over a file will indirectly call readline). + self._flags |= _FLAG_BUFFERED | _FLAG_LINE_BUFFERED + elif bufsize > 1: + self._bufsize = bufsize + self._flags |= _FLAG_BUFFERED + if ('r' in mode) or ('+' in mode): + self._flags |= _FLAG_READ + if ('w' in mode) or ('+' in mode): + self._flags |= _FLAG_WRITE + if ('a' in mode): + self._flags |= _FLAG_WRITE | _FLAG_APPEND + self._size = self._get_size() + self._pos = self._realpos = self._size + if ('b' in mode): + self._flags |= _FLAG_BINARY + if ('U' in mode): + self._flags |= _FLAG_UNIVERSAL_NEWLINE + # built-in file objects have this attribute to store which kinds of + # line terminations they've seen: + # <http://www.python.org/doc/current/lib/built-in-funcs.html> + self.newlines = None + + def _write_all(self, data): + # the underlying stream may be something that does partial writes (like + # a socket). + while len(data) > 0: + count = self._write(data) + data = data[count:] + if self._flags & _FLAG_APPEND: + self._size += count + self._pos = self._realpos = self._size + else: + self._pos += count + self._realpos += count + return None + + def _record_newline(self, newline): + # silliness about tracking what kinds of newlines we've seen. + # i don't understand why it can be None, a string, or a tuple, instead + # of just always being a tuple, but we'll emulate that behavior anyway. + if not (self._flags & _FLAG_UNIVERSAL_NEWLINE): + return + if self.newlines is None: + self.newlines = newline + elif (type(self.newlines) is str) and (self.newlines != newline): + self.newlines = (self.newlines, newline) + elif newline not in self.newlines: + self.newlines += (newline,) diff --git a/paramiko/kex_gex.py b/paramiko/kex_gex.py new file mode 100644 index 0000000..994d76c --- /dev/null +++ b/paramiko/kex_gex.py @@ -0,0 +1,202 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Variant on L{KexGroup1 <paramiko.kex_group1.KexGroup1>} where the prime "p" and +generator "g" are provided by the server. A bit more work is required on the +client side, and a B{lot} more on the server side. +""" + +from Crypto.Hash import SHA +from Crypto.Util import number + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ssh_exception import SSHException + + +_MSG_KEXDH_GEX_GROUP, _MSG_KEXDH_GEX_INIT, _MSG_KEXDH_GEX_REPLY, _MSG_KEXDH_GEX_REQUEST = range(31, 35) + + +class KexGex (object): + + name = 'diffie-hellman-group-exchange-sha1' + min_bits = 1024 + max_bits = 8192 + preferred_bits = 2048 + + def __init__(self, transport): + self.transport = transport + + def start_kex(self): + if self.transport.server_mode: + self.transport._expect_packet(_MSG_KEXDH_GEX_REQUEST) + return + # request a bit range: we accept (min_bits) to (max_bits), but prefer + # (preferred_bits). according to the spec, we shouldn't pull the + # minimum up above 1024. + m = Message() + m.add_byte(chr(_MSG_KEXDH_GEX_REQUEST)) + m.add_int(self.min_bits) + m.add_int(self.preferred_bits) + m.add_int(self.max_bits) + self.transport._send_message(m) + self.transport._expect_packet(_MSG_KEXDH_GEX_GROUP) + + def parse_next(self, ptype, m): + if ptype == _MSG_KEXDH_GEX_REQUEST: + return self._parse_kexdh_gex_request(m) + elif ptype == _MSG_KEXDH_GEX_GROUP: + return self._parse_kexdh_gex_group(m) + elif ptype == _MSG_KEXDH_GEX_INIT: + return self._parse_kexdh_gex_init(m) + elif ptype == _MSG_KEXDH_GEX_REPLY: + return self._parse_kexdh_gex_reply(m) + raise SSHException('KexGex asked to handle packet type %d' % ptype) + + + ### internals... + + + def _generate_x(self): + # generate an "x" (1 < x < (p-1)/2). + q = (self.p - 1) // 2 + qnorm = util.deflate_long(q, 0) + qhbyte = ord(qnorm[0]) + bytes = len(qnorm) + qmask = 0xff + while not (qhbyte & 0x80): + qhbyte <<= 1 + qmask >>= 1 + while True: + self.transport.randpool.stir() + x_bytes = self.transport.randpool.get_bytes(bytes) + x_bytes = chr(ord(x_bytes[0]) & qmask) + x_bytes[1:] + x = util.inflate_long(x_bytes, 1) + if (x > 1) and (x < q): + break + self.x = x + + def _parse_kexdh_gex_request(self, m): + minbits = m.get_int() + preferredbits = m.get_int() + maxbits = m.get_int() + # smoosh the user's preferred size into our own limits + if preferredbits > self.max_bits: + preferredbits = self.max_bits + if preferredbits < self.min_bits: + preferredbits = self.min_bits + # fix min/max if they're inconsistent. technically, we could just pout + # and hang up, but there's no harm in giving them the benefit of the + # doubt and just picking a bitsize for them. + if minbits > preferredbits: + minbits = preferredbits + if maxbits < preferredbits: + maxbits = preferredbits + # now save a copy + self.min_bits = minbits + self.preferred_bits = preferredbits + self.max_bits = maxbits + # generate prime + pack = self.transport._get_modulus_pack() + if pack is None: + raise SSHException('Can\'t do server-side gex with no modulus pack') + self.transport._log(DEBUG, 'Picking p (%d <= %d <= %d bits)' % (minbits, preferredbits, maxbits)) + self.g, self.p = pack.get_modulus(minbits, preferredbits, maxbits) + m = Message() + m.add_byte(chr(_MSG_KEXDH_GEX_GROUP)) + m.add_mpint(self.p) + m.add_mpint(self.g) + self.transport._send_message(m) + self.transport._expect_packet(_MSG_KEXDH_GEX_INIT) + + def _parse_kexdh_gex_group(self, m): + self.p = m.get_mpint() + self.g = m.get_mpint() + # reject if p's bit length < 1024 or > 8192 + bitlen = util.bit_length(self.p) + if (bitlen < 1024) or (bitlen > 8192): + raise SSHException('Server-generated gex p (don\'t ask) is out of range (%d bits)' % bitlen) + self.transport._log(DEBUG, 'Got server p (%d bits)' % bitlen) + self._generate_x() + # now compute e = g^x mod p + self.e = pow(self.g, self.x, self.p) + m = Message() + m.add_byte(chr(_MSG_KEXDH_GEX_INIT)) + m.add_mpint(self.e) + self.transport._send_message(m) + self.transport._expect_packet(_MSG_KEXDH_GEX_REPLY) + + def _parse_kexdh_gex_init(self, m): + self.e = m.get_mpint() + if (self.e < 1) or (self.e > self.p - 1): + raise SSHException('Client kex "e" is out of range') + self._generate_x() + self.f = pow(self.g, self.x, self.p) + K = pow(self.e, self.x, self.p) + key = str(self.transport.get_server_key()) + # okay, build up the hash H of (V_C || V_S || I_C || I_S || K_S || min || n || max || p || g || e || f || K) + hm = Message() + hm.add(self.transport.remote_version, self.transport.local_version, + self.transport.remote_kex_init, self.transport.local_kex_init, + key) + hm.add_int(self.min_bits) + hm.add_int(self.preferred_bits) + hm.add_int(self.max_bits) + hm.add_mpint(self.p) + hm.add_mpint(self.g) + hm.add_mpint(self.e) + hm.add_mpint(self.f) + hm.add_mpint(K) + H = SHA.new(str(hm)).digest() + self.transport._set_K_H(K, H) + # sign it + sig = self.transport.get_server_key().sign_ssh_data(self.transport.randpool, H) + # send reply + m = Message() + m.add_byte(chr(_MSG_KEXDH_GEX_REPLY)) + m.add_string(key) + m.add_mpint(self.f) + m.add_string(str(sig)) + self.transport._send_message(m) + self.transport._activate_outbound() + + def _parse_kexdh_gex_reply(self, m): + host_key = m.get_string() + self.f = m.get_mpint() + sig = m.get_string() + if (self.f < 1) or (self.f > self.p - 1): + raise SSHException('Server kex "f" is out of range') + K = pow(self.f, self.x, self.p) + # okay, build up the hash H of (V_C || V_S || I_C || I_S || K_S || min || n || max || p || g || e || f || K) + hm = Message() + hm.add(self.transport.local_version, self.transport.remote_version, + self.transport.local_kex_init, self.transport.remote_kex_init, + host_key) + hm.add_int(self.min_bits) + hm.add_int(self.preferred_bits) + hm.add_int(self.max_bits) + hm.add_mpint(self.p) + hm.add_mpint(self.g) + hm.add_mpint(self.e) + hm.add_mpint(self.f) + hm.add_mpint(K) + self.transport._set_K_H(K, SHA.new(str(hm)).digest()) + self.transport._verify_key(host_key, sig) + self.transport._activate_outbound() diff --git a/paramiko/kex_group1.py b/paramiko/kex_group1.py new file mode 100644 index 0000000..a13cf3a --- /dev/null +++ b/paramiko/kex_group1.py @@ -0,0 +1,136 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Standard SSH key exchange ("kex" if you wanna sound cool). Diffie-Hellman of +1024 bit key halves, using a known "p" prime and "g" generator. +""" + +from Crypto.Hash import SHA + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ssh_exception import SSHException + + +_MSG_KEXDH_INIT, _MSG_KEXDH_REPLY = range(30, 32) + +# draft-ietf-secsh-transport-09.txt, page 17 +P = 0xFFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFFL +G = 2 + + +class KexGroup1(object): + + name = 'diffie-hellman-group1-sha1' + + def __init__(self, transport): + self.transport = transport + self.x = 0L + self.e = 0L + self.f = 0L + + def start_kex(self): + self._generate_x() + if self.transport.server_mode: + # compute f = g^x mod p, but don't send it yet + self.f = pow(G, self.x, P) + self.transport._expect_packet(_MSG_KEXDH_INIT) + return + # compute e = g^x mod p (where g=2), and send it + self.e = pow(G, self.x, P) + m = Message() + m.add_byte(chr(_MSG_KEXDH_INIT)) + m.add_mpint(self.e) + self.transport._send_message(m) + self.transport._expect_packet(_MSG_KEXDH_REPLY) + + def parse_next(self, ptype, m): + if self.transport.server_mode and (ptype == _MSG_KEXDH_INIT): + return self._parse_kexdh_init(m) + elif not self.transport.server_mode and (ptype == _MSG_KEXDH_REPLY): + return self._parse_kexdh_reply(m) + raise SSHException('KexGroup1 asked to handle packet type %d' % ptype) + + + ### internals... + + + def _generate_x(self): + # generate an "x" (1 < x < q), where q is (p-1)/2. + # p is a 128-byte (1024-bit) number, where the first 64 bits are 1. + # therefore q can be approximated as a 2^1023. we drop the subset of + # potential x where the first 63 bits are 1, because some of those will be + # larger than q (but this is a tiny tiny subset of potential x). + while 1: + self.transport.randpool.stir() + x_bytes = self.transport.randpool.get_bytes(128) + x_bytes = chr(ord(x_bytes[0]) & 0x7f) + x_bytes[1:] + if (x_bytes[:8] != '\x7F\xFF\xFF\xFF\xFF\xFF\xFF\xFF') and \ + (x_bytes[:8] != '\x00\x00\x00\x00\x00\x00\x00\x00'): + break + self.x = util.inflate_long(x_bytes) + + def _parse_kexdh_reply(self, m): + # client mode + host_key = m.get_string() + self.f = m.get_mpint() + if (self.f < 1) or (self.f > P - 1): + raise SSHException('Server kex "f" is out of range') + sig = m.get_string() + K = pow(self.f, self.x, P) + # okay, build up the hash H of (V_C || V_S || I_C || I_S || K_S || e || f || K) + hm = Message() + hm.add(self.transport.local_version, self.transport.remote_version, + self.transport.local_kex_init, self.transport.remote_kex_init) + hm.add_string(host_key) + hm.add_mpint(self.e) + hm.add_mpint(self.f) + hm.add_mpint(K) + self.transport._set_K_H(K, SHA.new(str(hm)).digest()) + self.transport._verify_key(host_key, sig) + self.transport._activate_outbound() + + def _parse_kexdh_init(self, m): + # server mode + self.e = m.get_mpint() + if (self.e < 1) or (self.e > P - 1): + raise SSHException('Client kex "e" is out of range') + K = pow(self.e, self.x, P) + key = str(self.transport.get_server_key()) + # okay, build up the hash H of (V_C || V_S || I_C || I_S || K_S || e || f || K) + hm = Message() + hm.add(self.transport.remote_version, self.transport.local_version, + self.transport.remote_kex_init, self.transport.local_kex_init) + hm.add_string(key) + hm.add_mpint(self.e) + hm.add_mpint(self.f) + hm.add_mpint(K) + H = SHA.new(str(hm)).digest() + self.transport._set_K_H(K, H) + # sign it + sig = self.transport.get_server_key().sign_ssh_data(self.transport.randpool, H) + # send reply + m = Message() + m.add_byte(chr(_MSG_KEXDH_REPLY)) + m.add_string(key) + m.add_mpint(self.f) + m.add_string(str(sig)) + self.transport._send_message(m) + self.transport._activate_outbound() diff --git a/paramiko/logging22.py b/paramiko/logging22.py new file mode 100644 index 0000000..ac11a73 --- /dev/null +++ b/paramiko/logging22.py @@ -0,0 +1,66 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Stub out logging on python < 2.3. +""" + + +DEBUG = 10 +INFO = 20 +WARNING = 30 +ERROR = 40 +CRITICAL = 50 + + +def getLogger(name): + return _logger + + +class logger (object): + def __init__(self): + self.handlers = [ ] + self.level = ERROR + + def setLevel(self, level): + self.level = level + + def addHandler(self, h): + self.handlers.append(h) + + def addFilter(self, filter): + pass + + def log(self, level, text): + if level >= self.level: + for h in self.handlers: + h.f.write(text + '\n') + h.f.flush() + +class StreamHandler (object): + def __init__(self, f): + self.f = f + + def setFormatter(self, f): + pass + +class Formatter (object): + def __init__(self, x, y): + pass + +_logger = logger() diff --git a/paramiko/message.py b/paramiko/message.py new file mode 100644 index 0000000..1d75a01 --- /dev/null +++ b/paramiko/message.py @@ -0,0 +1,301 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Implementation of an SSH2 "message". +""" + +import struct +import cStringIO + +from paramiko import util + + +class Message (object): + """ + An SSH2 I{Message} is a stream of bytes that encodes some combination of + strings, integers, bools, and infinite-precision integers (known in python + as I{long}s). This class builds or breaks down such a byte stream. + + Normally you don't need to deal with anything this low-level, but it's + exposed for people implementing custom extensions, or features that + paramiko doesn't support yet. + """ + + def __init__(self, content=None): + """ + Create a new SSH2 Message. + + @param content: the byte stream to use as the Message content (passed + in only when decomposing a Message). + @type content: string + """ + if content != None: + self.packet = cStringIO.StringIO(content) + else: + self.packet = cStringIO.StringIO() + + def __str__(self): + """ + Return the byte stream content of this Message, as a string. + + @return: the contents of this Message. + @rtype: string + """ + return self.packet.getvalue() + + def __repr__(self): + """ + Returns a string representation of this object, for debugging. + + @rtype: string + """ + return 'paramiko.Message(' + repr(self.packet.getvalue()) + ')' + + def rewind(self): + """ + Rewind the message to the beginning as if no items had been parsed + out of it yet. + """ + self.packet.seek(0) + + def get_remainder(self): + """ + Return the bytes of this Message that haven't already been parsed and + returned. + + @return: a string of the bytes not parsed yet. + @rtype: string + """ + position = self.packet.tell() + remainder = self.packet.read() + self.packet.seek(position) + return remainder + + def get_so_far(self): + """ + Returns the bytes of this Message that have been parsed and returned. + The string passed into a Message's constructor can be regenerated by + concatenating C{get_so_far} and L{get_remainder}. + + @return: a string of the bytes parsed so far. + @rtype: string + """ + position = self.packet.tell() + self.rewind() + return self.packet.read(position) + + def get_bytes(self, n): + """ + Return the next C{n} bytes of the Message, without decomposing into + an int, string, etc. Just the raw bytes are returned. + + @return: a string of the next C{n} bytes of the Message, or a string + of C{n} zero bytes, if there aren't C{n} bytes remaining. + @rtype: string + """ + b = self.packet.read(n) + if len(b) < n: + return '\x00'*n + return b + + def get_byte(self): + """ + Return the next byte of the Message, without decomposing it. This + is equivalent to L{get_bytes(1)<get_bytes>}. + + @return: the next byte of the Message, or C{'\000'} if there aren't + any bytes remaining. + @rtype: string + """ + return self.get_bytes(1) + + def get_boolean(self): + """ + Fetch a boolean from the stream. + + @return: C{True} or C{False} (from the Message). + @rtype: bool + """ + b = self.get_bytes(1) + return b != '\x00' + + def get_int(self): + """ + Fetch an int from the stream. + + @return: a 32-bit unsigned integer. + @rtype: int + """ + return struct.unpack('>I', self.get_bytes(4))[0] + + def get_int64(self): + """ + Fetch a 64-bit int from the stream. + + @return: a 64-bit unsigned integer. + @rtype: long + """ + return struct.unpack('>Q', self.get_bytes(8))[0] + + def get_mpint(self): + """ + Fetch a long int (mpint) from the stream. + + @return: an arbitrary-length integer. + @rtype: long + """ + return util.inflate_long(self.get_string()) + + def get_string(self): + """ + Fetch a string from the stream. This could be a byte string and may + contain unprintable characters. (It's not unheard of for a string to + contain another byte-stream Message.) + + @return: a string. + @rtype: string + """ + return self.get_bytes(self.get_int()) + + def get_list(self): + """ + Fetch a list of strings from the stream. These are trivially encoded + as comma-separated values in a string. + + @return: a list of strings. + @rtype: list of strings + """ + return self.get_string().split(',') + + def add_bytes(self, b): + """ + Write bytes to the stream, without any formatting. + + @param b: bytes to add + @type b: str + """ + self.packet.write(b) + return self + + def add_byte(self, b): + """ + Write a single byte to the stream, without any formatting. + + @param b: byte to add + @type b: str + """ + self.packet.write(b) + return self + + def add_boolean(self, b): + """ + Add a boolean value to the stream. + + @param b: boolean value to add + @type b: bool + """ + if b: + self.add_byte('\x01') + else: + self.add_byte('\x00') + return self + + def add_int(self, n): + """ + Add an integer to the stream. + + @param n: integer to add + @type n: int + """ + self.packet.write(struct.pack('>I', n)) + return self + + def add_int64(self, n): + """ + Add a 64-bit int to the stream. + + @param n: long int to add + @type n: long + """ + self.packet.write(struct.pack('>Q', n)) + return self + + def add_mpint(self, z): + """ + Add a long int to the stream, encoded as an infinite-precision + integer. This method only works on positive numbers. + + @param z: long int to add + @type z: long + """ + self.add_string(util.deflate_long(z)) + return self + + def add_string(self, s): + """ + Add a string to the stream. + + @param s: string to add + @type s: str + """ + self.add_int(len(s)) + self.packet.write(s) + return self + + def add_list(self, l): + """ + Add a list of strings to the stream. They are encoded identically to + a single string of values separated by commas. (Yes, really, that's + how SSH2 does it.) + + @param l: list of strings to add + @type l: list(str) + """ + self.add_string(','.join(l)) + return self + + def _add(self, i): + if type(i) is str: + return self.add_string(i) + elif type(i) is int: + return self.add_int(i) + elif type(i) is long: + if i > 0xffffffffL: + return self.add_mpint(i) + else: + return self.add_int(i) + elif type(i) is bool: + return self.add_boolean(i) + elif type(i) is list: + return self.add_list(i) + else: + raise exception('Unknown type') + + def add(self, *seq): + """ + Add a sequence of items to the stream. The values are encoded based + on their type: str, int, bool, list, or long. + + @param seq: the sequence of items + @type seq: sequence + + @bug: longs are encoded non-deterministically. Don't use this method. + """ + for item in seq: + self._add(item) diff --git a/paramiko/packet.py b/paramiko/packet.py new file mode 100644 index 0000000..277d68e --- /dev/null +++ b/paramiko/packet.py @@ -0,0 +1,442 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Packetizer. +""" + +import select +import socket +import struct +import threading +import time +from Crypto.Hash import HMAC + +from paramiko.common import * +from paramiko import util +from paramiko.ssh_exception import SSHException +from paramiko.message import Message + + +class NeedRekeyException (Exception): + pass + + +class Packetizer (object): + """ + Implementation of the base SSH packet protocol. + """ + + # READ the secsh RFC's before raising these values. if anything, + # they should probably be lower. + REKEY_PACKETS = pow(2, 30) + REKEY_BYTES = pow(2, 30) + + def __init__(self, socket): + self.__socket = socket + self.__logger = None + self.__closed = False + self.__dump_packets = False + self.__need_rekey = False + self.__init_count = 0 + + # used for noticing when to re-key: + self.__sent_bytes = 0 + self.__sent_packets = 0 + self.__received_bytes = 0 + self.__received_packets = 0 + self.__received_packets_overflow = 0 + + # current inbound/outbound ciphering: + self.__block_size_out = 8 + self.__block_size_in = 8 + self.__mac_size_out = 0 + self.__mac_size_in = 0 + self.__block_engine_out = None + self.__block_engine_in = None + self.__mac_engine_out = None + self.__mac_engine_in = None + self.__mac_key_out = '' + self.__mac_key_in = '' + self.__compress_engine_out = None + self.__compress_engine_in = None + self.__sequence_number_out = 0L + self.__sequence_number_in = 0L + + # lock around outbound writes (packet computation) + self.__write_lock = threading.RLock() + + # keepalives: + self.__keepalive_interval = 0 + self.__keepalive_last = time.time() + self.__keepalive_callback = None + + def __del__(self): + # this is not guaranteed to be called, but we should try. + try: + self.__socket.close() + except: + pass + + def set_log(self, log): + """ + Set the python log object to use for logging. + """ + self.__logger = log + + def set_outbound_cipher(self, block_engine, block_size, mac_engine, mac_size, mac_key): + """ + Switch outbound data cipher. + """ + self.__block_engine_out = block_engine + self.__block_size_out = block_size + self.__mac_engine_out = mac_engine + self.__mac_size_out = mac_size + self.__mac_key_out = mac_key + self.__sent_bytes = 0 + self.__sent_packets = 0 + # wait until the reset happens in both directions before clearing rekey flag + self.__init_count |= 1 + if self.__init_count == 3: + self.__init_count = 0 + self.__need_rekey = False + + def set_inbound_cipher(self, block_engine, block_size, mac_engine, mac_size, mac_key): + """ + Switch inbound data cipher. + """ + self.__block_engine_in = block_engine + self.__block_size_in = block_size + self.__mac_engine_in = mac_engine + self.__mac_size_in = mac_size + self.__mac_key_in = mac_key + self.__received_bytes = 0 + self.__received_packets = 0 + self.__received_packets_overflow = 0 + # wait until the reset happens in both directions before clearing rekey flag + self.__init_count |= 2 + if self.__init_count == 3: + self.__init_count = 0 + self.__need_rekey = False + + def set_outbound_compressor(self, compressor): + self.__compress_engine_out = compressor + + def set_inbound_compressor(self, compressor): + self.__compress_engine_in = compressor + + def close(self): + self.__closed = True + + def set_hexdump(self, hexdump): + self.__dump_packets = hexdump + + def get_hexdump(self): + return self.__dump_packets + + def get_mac_size_in(self): + return self.__mac_size_in + + def get_mac_size_out(self): + return self.__mac_size_out + + def need_rekey(self): + """ + Returns C{True} if a new set of keys needs to be negotiated. This + will be triggered during a packet read or write, so it should be + checked after every read or write, or at least after every few. + + @return: C{True} if a new set of keys needs to be negotiated + """ + return self.__need_rekey + + def set_keepalive(self, interval, callback): + """ + Turn on/off the callback keepalive. If C{interval} seconds pass with + no data read from or written to the socket, the callback will be + executed and the timer will be reset. + """ + self.__keepalive_interval = interval + self.__keepalive_callback = callback + self.__keepalive_last = time.time() + + def read_all(self, n, check_rekey=False): + """ + Read as close to N bytes as possible, blocking as long as necessary. + + @param n: number of bytes to read + @type n: int + @return: the data read + @rtype: str + @raise EOFError: if the socket was closed before all the bytes could + be read + """ + if PY22: + return self._py22_read_all(n) + out = '' + while n > 0: + try: + x = self.__socket.recv(n) + if len(x) == 0: + raise EOFError() + out += x + n -= len(x) + except socket.timeout: + if self.__closed: + raise EOFError() + if check_rekey and (len(out) == 0) and self.__need_rekey: + raise NeedRekeyException() + self._check_keepalive() + return out + + def write_all(self, out): + self.__keepalive_last = time.time() + while len(out) > 0: + try: + n = self.__socket.send(out) + except socket.timeout: + n = 0 + if self.__closed: + n = -1 + except Exception: + # could be: (32, 'Broken pipe') + n = -1 + if n < 0: + raise EOFError() + if n == len(out): + return + out = out[n:] + return + + def readline(self, timeout): + """ + Read a line from the socket. This is done in a fairly inefficient + way, but is only used for initial banner negotiation so it's not worth + optimising. + """ + buf = '' + while not '\n' in buf: + buf += self._read_timeout(timeout) + buf = buf[:-1] + if (len(buf) > 0) and (buf[-1] == '\r'): + buf = buf[:-1] + return buf + + def send_message(self, data): + """ + Write a block of data using the current cipher, as an SSH block. + """ + # encrypt this sucka + randpool.stir() + data = str(data) + cmd = ord(data[0]) + if cmd in MSG_NAMES: + cmd_name = MSG_NAMES[cmd] + else: + cmd_name = '$%x' % cmd + self._log(DEBUG, 'Write packet <%s>, length %d' % (cmd_name, len(data))) + if self.__compress_engine_out is not None: + data = self.__compress_engine_out(data) + packet = self._build_packet(data) + if self.__dump_packets: + self._log(DEBUG, util.format_binary(packet, 'OUT: ')) + self.__write_lock.acquire() + try: + if self.__block_engine_out != None: + out = self.__block_engine_out.encrypt(packet) + else: + out = packet + # + mac + if self.__block_engine_out != None: + payload = struct.pack('>I', self.__sequence_number_out) + packet + out += HMAC.HMAC(self.__mac_key_out, payload, self.__mac_engine_out).digest()[:self.__mac_size_out] + self.__sequence_number_out = (self.__sequence_number_out + 1) & 0xffffffffL + self.write_all(out) + + self.__sent_bytes += len(out) + self.__sent_packets += 1 + if ((self.__sent_packets >= self.REKEY_PACKETS) or (self.__sent_bytes >= self.REKEY_BYTES)) \ + and not self.__need_rekey: + # only ask once for rekeying + self._log(DEBUG, 'Rekeying (hit %d packets, %d bytes sent)' % + (self.__sent_packets, self.__sent_bytes)) + self.__received_packets_overflow = 0 + self._trigger_rekey() + finally: + self.__write_lock.release() + + def read_message(self): + """ + Only one thread should ever be in this function (no other locking is + done). + + @raise SSHException: if the packet is mangled + @raise NeedRekeyException: if the transport should rekey + """ + header = self.read_all(self.__block_size_in, check_rekey=True) + if self.__block_engine_in != None: + header = self.__block_engine_in.decrypt(header) + if self.__dump_packets: + self._log(DEBUG, util.format_binary(header, 'IN: ')); + packet_size = struct.unpack('>I', header[:4])[0] + # leftover contains decrypted bytes from the first block (after the length field) + leftover = header[4:] + if (packet_size - len(leftover)) % self.__block_size_in != 0: + raise SSHException('Invalid packet blocking') + buf = self.read_all(packet_size + self.__mac_size_in - len(leftover)) + packet = buf[:packet_size - len(leftover)] + post_packet = buf[packet_size - len(leftover):] + if self.__block_engine_in != None: + packet = self.__block_engine_in.decrypt(packet) + if self.__dump_packets: + self._log(DEBUG, util.format_binary(packet, 'IN: ')); + packet = leftover + packet + + if self.__mac_size_in > 0: + mac = post_packet[:self.__mac_size_in] + mac_payload = struct.pack('>II', self.__sequence_number_in, packet_size) + packet + my_mac = HMAC.HMAC(self.__mac_key_in, mac_payload, self.__mac_engine_in).digest()[:self.__mac_size_in] + if my_mac != mac: + raise SSHException('Mismatched MAC') + padding = ord(packet[0]) + payload = packet[1:packet_size - padding] + randpool.add_event(packet[packet_size - padding]) + if self.__dump_packets: + self._log(DEBUG, 'Got payload (%d bytes, %d padding)' % (packet_size, padding)) + + if self.__compress_engine_in is not None: + payload = self.__compress_engine_in(payload) + + msg = Message(payload[1:]) + msg.seqno = self.__sequence_number_in + self.__sequence_number_in = (self.__sequence_number_in + 1) & 0xffffffffL + + # check for rekey + self.__received_bytes += packet_size + self.__mac_size_in + 4 + self.__received_packets += 1 + if self.__need_rekey: + # we've asked to rekey -- give them 20 packets to comply before + # dropping the connection + self.__received_packets_overflow += 1 + if self.__received_packets_overflow >= 20: + raise SSHException('Remote transport is ignoring rekey requests') + elif (self.__received_packets >= self.REKEY_PACKETS) or \ + (self.__received_bytes >= self.REKEY_BYTES): + # only ask once for rekeying + self._log(DEBUG, 'Rekeying (hit %d packets, %d bytes received)' % + (self.__received_packets, self.__received_bytes)) + self.__received_packets_overflow = 0 + self._trigger_rekey() + + cmd = ord(payload[0]) + if cmd in MSG_NAMES: + cmd_name = MSG_NAMES[cmd] + else: + cmd_name = '$%x' % cmd + self._log(DEBUG, 'Read packet <%s>, length %d' % (cmd_name, len(payload))) + return cmd, msg + + + ########## protected + + + def _log(self, level, msg): + if self.__logger is None: + return + if issubclass(type(msg), list): + for m in msg: + self.__logger.log(level, m) + else: + self.__logger.log(level, msg) + + def _check_keepalive(self): + if (not self.__keepalive_interval) or (not self.__block_engine_out) or \ + self.__need_rekey: + # wait till we're encrypting, and not in the middle of rekeying + return + now = time.time() + if now > self.__keepalive_last + self.__keepalive_interval: + self.__keepalive_callback() + self.__keepalive_last = now + + def _py22_read_all(self, n): + out = '' + while n > 0: + r, w, e = select.select([self.__socket], [], [], 0.1) + if self.__socket not in r: + if self.__closed: + raise EOFError() + self._check_keepalive() + else: + x = self.__socket.recv(n) + if len(x) == 0: + raise EOFError() + out += x + n -= len(x) + return out + + def _py22_read_timeout(self, timeout): + start = time.time() + while True: + r, w, e = select.select([self.__socket], [], [], 0.1) + if self.__socket in r: + x = self.__socket.recv(1) + if len(x) == 0: + raise EOFError() + return x + if self.__closed: + raise EOFError() + now = time.time() + if now - start >= timeout: + raise socket.timeout() + + def _read_timeout(self, timeout): + if PY22: + return self._py22_read_timeout(n) + start = time.time() + while True: + try: + x = self.__socket.recv(1) + if len(x) == 0: + raise EOFError() + return x + except socket.timeout: + pass + if self.__closed: + raise EOFError() + now = time.time() + if now - start >= timeout: + raise socket.timeout() + + def _build_packet(self, payload): + # pad up at least 4 bytes, to nearest block-size (usually 8) + bsize = self.__block_size_out + padding = 3 + bsize - ((len(payload) + 8) % bsize) + packet = struct.pack('>IB', len(payload) + padding + 1, padding) + packet += payload + if self.__block_engine_out is not None: + packet += randpool.get_bytes(padding) + else: + # cute trick i caught openssh doing: if we're not encrypting, + # don't waste random bytes for the padding + packet += (chr(0) * padding) + return packet + + def _trigger_rekey(self): + # outside code should check for this flag + self.__need_rekey = True diff --git a/paramiko/pipe.py b/paramiko/pipe.py new file mode 100644 index 0000000..cc28f43 --- /dev/null +++ b/paramiko/pipe.py @@ -0,0 +1,105 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Abstraction of a one-way pipe where the read end can be used in select(). +Normally this is trivial, but Windows makes it nearly impossible. +""" + +import sys +import os +import socket + + +def make_pipe (): + if sys.platform[:3] != 'win': + return PosixPipe() + return WindowsPipe() + + +class PosixPipe (object): + def __init__ (self): + self._rfd, self._wfd = os.pipe() + self._set = False + self._forever = False + + def close (self): + os.close(self._rfd) + os.close(self._wfd) + + def fileno (self): + return self._rfd + + def clear (self): + if not self._set or self._forever: + return + os.read(self._rfd, 1) + self._set = False + + def set (self): + if self._set: + return + self._set = True + os.write(self._wfd, '*') + + def set_forever (self): + self._forever = True + self.set() + + +class WindowsPipe (object): + """ + On Windows, only an OS-level "WinSock" may be used in select(), but reads + and writes must be to the actual socket object. + """ + def __init__ (self): + serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + serv.bind(('127.0.0.1', 0)) + serv.listen(1) + + # need to save sockets in _rsock/_wsock so they don't get closed + self._rsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + self._rsock.connect(('127.0.0.1', serv.getsockname()[1])) + + self._wsock, addr = serv.accept() + serv.close() + self._set = False + self._forever = False + + def close (self): + self._rsock.close() + self._wsock.close() + + def fileno (self): + return self._rsock.fileno() + + def clear (self): + if not self._set or self._forever: + return + self._rsock.recv(1) + self._set = False + + def set (self): + if self._set: + return + self._set = True + self._wsock.send('*') + + def set_forever (self): + self._forever = True + self.set() diff --git a/paramiko/pkey.py b/paramiko/pkey.py new file mode 100644 index 0000000..75db8e5 --- /dev/null +++ b/paramiko/pkey.py @@ -0,0 +1,339 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Common API for all public keys. +""" + +import base64 +import os + +from Crypto.Hash import MD5 +from Crypto.Cipher import DES3 + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ssh_exception import SSHException, PasswordRequiredException + + +class PKey (object): + """ + Base class for public keys. + """ + + # known encryption types for private key files: + _CIPHER_TABLE = { + 'DES-EDE3-CBC': { 'cipher': DES3, 'keysize': 24, 'blocksize': 8, 'mode': DES3.MODE_CBC } + } + + + def __init__(self, msg=None, data=None): + """ + Create a new instance of this public key type. If C{msg} is given, + the key's public part(s) will be filled in from the message. If + C{data} is given, the key's public part(s) will be filled in from + the string. + + @param msg: an optional SSH L{Message} containing a public key of this + type. + @type msg: L{Message} + @param data: an optional string containing a public key of this type + @type data: str + + @raise SSHException: if a key cannot be created from the C{data} or + C{msg} given, or no key was passed in. + """ + pass + + def __str__(self): + """ + Return a string of an SSH L{Message} made up of the public part(s) of + this key. This string is suitable for passing to L{__init__} to + re-create the key object later. + + @return: string representation of an SSH key message. + @rtype: str + """ + return '' + + def __cmp__(self, other): + """ + Compare this key to another. Returns 0 if this key is equivalent to + the given key, or non-0 if they are different. Only the public parts + of the key are compared, so a public key will compare equal to its + corresponding private key. + + @param other: key to compare to. + @type other: L{PKey} + @return: 0 if the two keys are equivalent, non-0 otherwise. + @rtype: int + """ + hs = hash(self) + ho = hash(other) + if hs != ho: + return cmp(hs, ho) + return cmp(str(self), str(other)) + + def get_name(self): + """ + Return the name of this private key implementation. + + @return: name of this private key type, in SSH terminology (for + example, C{"ssh-rsa"}). + @rtype: str + """ + return '' + + def get_bits(self): + """ + Return the number of significant bits in this key. This is useful + for judging the relative security of a key. + + @return: bits in the key. + @rtype: int + """ + return 0 + + def can_sign(self): + """ + Return C{True} if this key has the private part necessary for signing + data. + + @return: C{True} if this is a private key. + @rtype: bool + """ + return False + + def get_fingerprint(self): + """ + Return an MD5 fingerprint of the public part of this key. Nothing + secret is revealed. + + @return: a 16-byte string (binary) of the MD5 fingerprint, in SSH + format. + @rtype: str + """ + return MD5.new(str(self)).digest() + + def get_base64(self): + """ + Return a base64 string containing the public part of this key. Nothing + secret is revealed. This format is compatible with that used to store + public key files or recognized host keys. + + @return: a base64 string containing the public part of the key. + @rtype: str + + @since: fearow + """ + return base64.encodestring(str(self)).replace('\n', '') + + def sign_ssh_data(self, randpool, data): + """ + Sign a blob of data with this private key, and return a L{Message} + representing an SSH signature message. + + @param randpool: a secure random number generator. + @type randpool: L{Crypto.Util.randpool.RandomPool} + @param data: the data to sign. + @type data: str + @return: an SSH signature message. + @rtype: L{Message} + """ + return '' + + def verify_ssh_sig(self, data, msg): + """ + Given a blob of data, and an SSH message representing a signature of + that data, verify that it was signed with this key. + + @param data: the data that was signed. + @type data: str + @param msg: an SSH signature message + @type msg: L{Message} + @return: C{True} if the signature verifies correctly; C{False} + otherwise. + @rtype: boolean + """ + return False + + def from_private_key_file(cl, filename, password=None): + """ + Create a key object by reading a private key file. If the private + key is encrypted and C{password} is not C{None}, the given password + will be used to decrypt the key (otherwise L{PasswordRequiredException} + is thrown). Through the magic of python, this factory method will + exist in all subclasses of PKey (such as L{RSAKey} or L{DSSKey}), but + is useless on the abstract PKey class. + + @param filename: name of the file to read. + @type filename: str + @param password: an optional password to use to decrypt the key file, + if it's encrypted + @type password: str + @return: a new key object based on the given private key. + @rtype: L{PKey} + + @raise IOError: if there was an error reading the file. + @raise PasswordRequiredException: if the private key file is + encrypted, and C{password} is C{None}. + @raise SSHException: if the key file is invalid. + + @since: fearow + """ + key = cl(filename=filename, password=password) + return key + from_private_key_file = classmethod(from_private_key_file) + + def write_private_key_file(self, filename, password=None): + """ + Write private key contents into a file. If the password is not + C{None}, the key is encrypted before writing. + + @param filename: name of the file to write. + @type filename: str + @param password: an optional password to use to encrypt the key file. + @type password: str + + @raise IOError: if there was an error writing the file. + @raise SSHException: if the key is invalid. + + @since: fearow + """ + raise exception('Not implemented in PKey') + + def _read_private_key_file(self, tag, filename, password=None): + """ + Read an SSH2-format private key file, looking for a string of the type + C{"BEGIN xxx PRIVATE KEY"} for some C{xxx}, base64-decode the text we + find, and return it as a string. If the private key is encrypted and + C{password} is not C{None}, the given password will be used to decrypt + the key (otherwise L{PasswordRequiredException} is thrown). + + @param tag: C{"RSA"} or C{"DSA"}, the tag used to mark the data block. + @type tag: str + @param filename: name of the file to read. + @type filename: str + @param password: an optional password to use to decrypt the key file, + if it's encrypted. + @type password: str + @return: data blob that makes up the private key. + @rtype: str + + @raise IOError: if there was an error reading the file. + @raise PasswordRequiredException: if the private key file is + encrypted, and C{password} is C{None}. + @raise SSHException: if the key file is invalid. + """ + f = open(filename, 'r') + lines = f.readlines() + f.close() + start = 0 + while (start < len(lines)) and (lines[start].strip() != '-----BEGIN ' + tag + ' PRIVATE KEY-----'): + start += 1 + if start >= len(lines): + raise SSHException('not a valid ' + tag + ' private key file') + # parse any headers first + headers = {} + start += 1 + while start < len(lines): + l = lines[start].split(': ') + if len(l) == 1: + break + headers[l[0].lower()] = l[1].strip() + start += 1 + # find end + end = start + while (lines[end].strip() != '-----END ' + tag + ' PRIVATE KEY-----') and (end < len(lines)): + end += 1 + # if we trudged to the end of the file, just try to cope. + try: + data = base64.decodestring(''.join(lines[start:end])) + except binascii.Error, e: + raise SSHException('base64 decoding error: ' + str(e)) + if not headers.has_key('proc-type'): + # unencryped: done + return data + # encrypted keyfile: will need a password + if headers['proc-type'] != '4,ENCRYPTED': + raise SSHException('Unknown private key structure "%s"' % headers['proc-type']) + try: + encryption_type, saltstr = headers['dek-info'].split(',') + except: + raise SSHException('Can\'t parse DEK-info in private key file') + if not self._CIPHER_TABLE.has_key(encryption_type): + raise SSHException('Unknown private key cipher "%s"' % encryption_type) + # if no password was passed in, raise an exception pointing out that we need one + if password is None: + raise PasswordRequiredException('Private key file is encrypted') + cipher = self._CIPHER_TABLE[encryption_type]['cipher'] + keysize = self._CIPHER_TABLE[encryption_type]['keysize'] + mode = self._CIPHER_TABLE[encryption_type]['mode'] + salt = util.unhexify(saltstr) + key = util.generate_key_bytes(MD5, salt, password, keysize) + return cipher.new(key, mode, salt).decrypt(data) + + def _write_private_key_file(self, tag, filename, data, password=None): + """ + Write an SSH2-format private key file in a form that can be read by + paramiko or openssh. If no password is given, the key is written in + a trivially-encoded format (base64) which is completely insecure. If + a password is given, DES-EDE3-CBC is used. + + @param tag: C{"RSA"} or C{"DSA"}, the tag used to mark the data block. + @type tag: str + @param filename: name of the file to write. + @type filename: str + @param data: data blob that makes up the private key. + @type data: str + @param password: an optional password to use to encrypt the file. + @type password: str + + @raise IOError: if there was an error writing the file. + """ + f = open(filename, 'w', 0600) + # grrr... the mode doesn't always take hold + os.chmod(filename, 0600) + f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag) + if password is not None: + # since we only support one cipher here, use it + cipher_name = self._CIPHER_TABLE.keys()[0] + cipher = self._CIPHER_TABLE[cipher_name]['cipher'] + keysize = self._CIPHER_TABLE[cipher_name]['keysize'] + blocksize = self._CIPHER_TABLE[cipher_name]['blocksize'] + mode = self._CIPHER_TABLE[cipher_name]['mode'] + salt = randpool.get_bytes(8) + key = util.generate_key_bytes(MD5, salt, password, keysize) + if len(data) % blocksize != 0: + n = blocksize - len(data) % blocksize + #data += randpool.get_bytes(n) + # that would make more sense ^, but it confuses openssh. + data += '\0' * n + data = cipher.new(key, mode, salt).encrypt(data) + f.write('Proc-Type: 4,ENCRYPTED\n') + f.write('DEK-Info: %s,%s\n' % (cipher_name, util.hexify(salt))) + f.write('\n') + s = base64.encodestring(data) + # re-wrap to 64-char lines + s = ''.join(s.split('\n')) + s = '\n'.join([s[i : i+64] for i in range(0, len(s), 64)]) + f.write(s) + f.write('\n') + f.write('-----END %s PRIVATE KEY-----\n' % tag) + f.close() diff --git a/paramiko/primes.py b/paramiko/primes.py new file mode 100644 index 0000000..3677394 --- /dev/null +++ b/paramiko/primes.py @@ -0,0 +1,148 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Utility functions for dealing with primes. +""" + +from Crypto.Util import number + +from paramiko import util + + +def _generate_prime(bits, randpool): + "primtive attempt at prime generation" + hbyte_mask = pow(2, bits % 8) - 1 + while True: + # loop catches the case where we increment n into a higher bit-range + x = randpool.get_bytes((bits+7) // 8) + if hbyte_mask > 0: + x = chr(ord(x[0]) & hbyte_mask) + x[1:] + n = util.inflate_long(x, 1) + n |= 1 + n |= (1 << (bits - 1)) + while not number.isPrime(n): + n += 2 + if util.bit_length(n) == bits: + return n + +def _roll_random(rpool, n): + "returns a random # from 0 to N-1" + bits = util.bit_length(n-1) + bytes = (bits + 7) // 8 + hbyte_mask = pow(2, bits % 8) - 1 + + # so here's the plan: + # we fetch as many random bits as we'd need to fit N-1, and if the + # generated number is >= N, we try again. in the worst case (N-1 is a + # power of 2), we have slightly better than 50% odds of getting one that + # fits, so i can't guarantee that this loop will ever finish, but the odds + # of it looping forever should be infinitesimal. + while True: + x = rpool.get_bytes(bytes) + if hbyte_mask > 0: + x = chr(ord(x[0]) & hbyte_mask) + x[1:] + num = util.inflate_long(x, 1) + if num < n: + return num + + +class ModulusPack (object): + """ + convenience object for holding the contents of the /etc/ssh/moduli file, + on systems that have such a file. + """ + + def __init__(self, rpool): + # pack is a hash of: bits -> [ (generator, modulus) ... ] + self.pack = {} + self.discarded = [] + self.randpool = rpool + + def _parse_modulus(self, line): + timestamp, type, tests, tries, size, generator, modulus = line.split() + type = int(type) + tests = int(tests) + tries = int(tries) + size = int(size) + generator = int(generator) + modulus = long(modulus, 16) + + # weed out primes that aren't at least: + # type 2 (meets basic structural requirements) + # test 4 (more than just a small-prime sieve) + # tries < 100 if test & 4 (at least 100 tries of miller-rabin) + if (type < 2) or (tests < 4) or ((tests & 4) and (tests < 8) and (tries < 100)): + self.discarded.append((modulus, 'does not meet basic requirements')) + return + if generator == 0: + generator = 2 + + # there's a bug in the ssh "moduli" file (yeah, i know: shock! dismay! + # call cnn!) where it understates the bit lengths of these primes by 1. + # this is okay. + bl = util.bit_length(modulus) + if (bl != size) and (bl != size + 1): + self.discarded.append((modulus, 'incorrectly reported bit length %d' % size)) + return + if not self.pack.has_key(bl): + self.pack[bl] = [] + self.pack[bl].append((generator, modulus)) + + def read_file(self, filename): + """ + @raise IOError: passed from any file operations that fail. + """ + self.pack = {} + f = open(filename, 'r') + for line in f: + line = line.strip() + if (len(line) == 0) or (line[0] == '#'): + continue + try: + self._parse_modulus(line) + except: + continue + f.close() + + def get_modulus(self, min, prefer, max): + bitsizes = self.pack.keys() + bitsizes.sort() + if len(bitsizes) == 0: + raise SSHException('no moduli available') + good = -1 + # find nearest bitsize >= preferred + for b in bitsizes: + if (b >= prefer) and (b < max) and ((b < good) or (good == -1)): + good = b + # if that failed, find greatest bitsize >= min + if good == -1: + for b in bitsizes: + if (b >= min) and (b < max) and (b > good): + good = b + if good == -1: + # their entire (min, max) range has no intersection with our range. + # if their range is below ours, pick the smallest. otherwise pick + # the largest. it'll be out of their range requirement either way, + # but we'll be sending them the closest one we have. + good = bitsizes[0] + if min > good: + good = bitsizes[-1] + # now pick a random modulus of this bitsize + n = _roll_random(self.randpool, len(self.pack[good])) + return self.pack[good][n] diff --git a/paramiko/rsakey.py b/paramiko/rsakey.py new file mode 100644 index 0000000..780ea1b --- /dev/null +++ b/paramiko/rsakey.py @@ -0,0 +1,165 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{RSAKey} +""" + +from Crypto.PublicKey import RSA +from Crypto.Hash import SHA, MD5 +from Crypto.Cipher import DES3 + +from paramiko.common import * +from paramiko import util +from paramiko.message import Message +from paramiko.ber import BER, BERException +from paramiko.pkey import PKey +from paramiko.ssh_exception import SSHException + + +class RSAKey (PKey): + """ + Representation of an RSA key which can be used to sign and verify SSH2 + data. + """ + + def __init__(self, msg=None, data=None, filename=None, password=None, vals=None): + if filename is not None: + self._from_private_key_file(filename, password) + return + if (msg is None) and (data is not None): + msg = Message(data) + if vals is not None: + self.e, self.n = vals + else: + if msg is None: + raise SSHException('Key object may not be empty') + if msg.get_string() != 'ssh-rsa': + raise SSHException('Invalid key') + self.e = msg.get_mpint() + self.n = msg.get_mpint() + self.size = util.bit_length(self.n) + + def __str__(self): + m = Message() + m.add_string('ssh-rsa') + m.add_mpint(self.e) + m.add_mpint(self.n) + return str(m) + + def __hash__(self): + h = hash(self.get_name()) + h = h * 37 + hash(self.e) + h = h * 37 + hash(self.n) + return hash(h) + + def get_name(self): + return 'ssh-rsa' + + def get_bits(self): + return self.size + + def can_sign(self): + return hasattr(self, 'd') + + def sign_ssh_data(self, rpool, data): + digest = SHA.new(data).digest() + rsa = RSA.construct((long(self.n), long(self.e), long(self.d))) + sig = util.deflate_long(rsa.sign(self._pkcs1imify(digest), '')[0], 0) + m = Message() + m.add_string('ssh-rsa') + m.add_string(sig) + return m + + def verify_ssh_sig(self, data, msg): + if msg.get_string() != 'ssh-rsa': + return False + sig = util.inflate_long(msg.get_string(), True) + # verify the signature by SHA'ing the data and encrypting it using the + # public key. some wackiness ensues where we "pkcs1imify" the 20-byte + # hash into a string as long as the RSA key. + hash = util.inflate_long(self._pkcs1imify(SHA.new(data).digest()), True) + rsa = RSA.construct((long(self.n), long(self.e))) + return rsa.verify(hash, (sig,)) + + def write_private_key_file(self, filename, password=None): + keylist = [ 0, self.n, self.e, self.d, self.p, self.q, + self.d % (self.p - 1), self.d % (self.q - 1), + util.mod_inverse(self.q, self.p) ] + try: + b = BER() + b.encode(keylist) + except BERException: + raise SSHException('Unable to create ber encoding of key') + self._write_private_key_file('RSA', filename, str(b), password) + + def generate(bits, progress_func=None): + """ + Generate a new private RSA key. This factory function can be used to + generate a new host key or authentication key. + + @param bits: number of bits the generated key should be. + @type bits: int + @param progress_func: an optional function to call at key points in + key generation (used by C{pyCrypto.PublicKey}). + @type progress_func: function + @return: new private key + @rtype: L{RSAKey} + + @since: fearow + """ + randpool.stir() + rsa = RSA.generate(bits, randpool.get_bytes, progress_func) + key = RSAKey(vals=(rsa.e, rsa.n)) + key.d = rsa.d + key.p = rsa.p + key.q = rsa.q + return key + generate = staticmethod(generate) + + + ### internals... + + + def _pkcs1imify(self, data): + """ + turn a 20-byte SHA1 hash into a blob of data as large as the key's N, + using PKCS1's \"emsa-pkcs1-v1_5\" encoding. totally bizarre. + """ + SHA1_DIGESTINFO = '\x30\x21\x30\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14' + size = len(util.deflate_long(self.n, 0)) + filler = '\xff' * (size - len(SHA1_DIGESTINFO) - len(data) - 3) + return '\x00\x01' + filler + '\x00' + SHA1_DIGESTINFO + data + + def _from_private_key_file(self, filename, password): + # private key file contains: + # RSAPrivateKey = { version = 0, n, e, d, p, q, d mod p-1, d mod q-1, q**-1 mod p } + data = self._read_private_key_file('RSA', filename, password) + try: + keylist = BER(data).decode() + except BERException: + raise SSHException('Unable to parse key file') + if (type(keylist) is not list) or (len(keylist) < 4) or (keylist[0] != 0): + raise SSHException('Not a valid RSA private key file (bad ber encoding)') + self.n = keylist[1] + self.e = keylist[2] + self.d = keylist[3] + # not really needed + self.p = keylist[4] + self.q = keylist[5] + self.size = util.bit_length(self.n) diff --git a/paramiko/server.py b/paramiko/server.py new file mode 100644 index 0000000..a0e3988 --- /dev/null +++ b/paramiko/server.py @@ -0,0 +1,527 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{ServerInterface} is an interface to override for server support. +""" + +import threading +from paramiko.common import * +from paramiko import util + + +class InteractiveQuery (object): + """ + A query (set of prompts) for a user during interactive authentication. + """ + + def __init__(self, name='', instructions='', *prompts): + """ + Create a new interactive query to send to the client. The name and + instructions are optional, but are generally displayed to the end + user. A list of prompts may be included, or they may be added via + the L{add_prompt} method. + + @param name: name of this query + @type name: str + @param instructions: user instructions (usually short) about this query + @type instructions: str + """ + self.name = name + self.instructions = instructions + self.prompts = [] + for x in prompts: + if (type(x) is str) or (type(x) is unicode): + self.add_prompt(x) + else: + self.add_prompt(x[0], x[1]) + + def add_prompt(self, prompt, echo=True): + """ + Add a prompt to this query. The prompt should be a (reasonably short) + string. Multiple prompts can be added to the same query. + + @param prompt: the user prompt + @type prompt: str + @param echo: C{True} (default) if the user's response should be echoed; + C{False} if not (for a password or similar) + @type echo: bool + """ + self.prompts.append((prompt, echo)) + + +class ServerInterface (object): + """ + This class defines an interface for controlling the behavior of paramiko + in server mode. + + Methods on this class are called from paramiko's primary thread, so you + shouldn't do too much work in them. (Certainly nothing that blocks or + sleeps.) + """ + + def check_channel_request(self, kind, chanid): + """ + Determine if a channel request of a given type will be granted, and + return C{OPEN_SUCCEEDED} or an error code. This method is + called in server mode when the client requests a channel, after + authentication is complete. + + If you allow channel requests (and an ssh server that didn't would be + useless), you should also override some of the channel request methods + below, which are used to determine which services will be allowed on + a given channel: + - L{check_channel_pty_request} + - L{check_channel_shell_request} + - L{check_channel_subsystem_request} + - L{check_channel_window_change_request} + + The C{chanid} parameter is a small number that uniquely identifies the + channel within a L{Transport}. A L{Channel} object is not created + unless this method returns C{OPEN_SUCCEEDED} -- once a + L{Channel} object is created, you can call L{Channel.get_id} to + retrieve the channel ID. + + The return value should either be C{OPEN_SUCCEEDED} (or + C{0}) to allow the channel request, or one of the following error + codes to reject it: + - C{OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED} + - C{OPEN_FAILED_CONNECT_FAILED} + - C{OPEN_FAILED_UNKNOWN_CHANNEL_TYPE} + - C{OPEN_FAILED_RESOURCE_SHORTAGE} + + The default implementation always returns + C{OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED}. + + @param kind: the kind of channel the client would like to open + (usually C{"session"}). + @type kind: str + @param chanid: ID of the channel + @type chanid: int + @return: a success or failure code (listed above) + @rtype: int + """ + return OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED + + def get_allowed_auths(self, username): + """ + Return a list of authentication methods supported by the server. + This list is sent to clients attempting to authenticate, to inform them + of authentication methods that might be successful. + + The "list" is actually a string of comma-separated names of types of + authentication. Possible values are C{"password"}, C{"publickey"}, + and C{"none"}. + + The default implementation always returns C{"password"}. + + @param username: the username requesting authentication. + @type username: str + @return: a comma-separated list of authentication types + @rtype: str + """ + return 'password' + + def check_auth_none(self, username): + """ + Determine if a client may open channels with no (further) + authentication. + + Return L{AUTH_FAILED} if the client must authenticate, or + L{AUTH_SUCCESSFUL} if it's okay for the client to not + authenticate. + + The default implementation always returns L{AUTH_FAILED}. + + @param username: the username of the client. + @type username: str + @return: L{AUTH_FAILED} if the authentication fails; + L{AUTH_SUCCESSFUL} if it succeeds. + @rtype: int + """ + return AUTH_FAILED + + def check_auth_password(self, username, password): + """ + Determine if a given username and password supplied by the client is + acceptable for use in authentication. + + Return L{AUTH_FAILED} if the password is not accepted, + L{AUTH_SUCCESSFUL} if the password is accepted and completes + the authentication, or L{AUTH_PARTIALLY_SUCCESSFUL} if your + authentication is stateful, and this key is accepted for + authentication, but more authentication is required. (In this latter + case, L{get_allowed_auths} will be called to report to the client what + options it has for continuing the authentication.) + + The default implementation always returns L{AUTH_FAILED}. + + @param username: the username of the authenticating client. + @type username: str + @param password: the password given by the client. + @type password: str + @return: L{AUTH_FAILED} if the authentication fails; + L{AUTH_SUCCESSFUL} if it succeeds; + L{AUTH_PARTIALLY_SUCCESSFUL} if the password auth is + successful, but authentication must continue. + @rtype: int + """ + return AUTH_FAILED + + def check_auth_publickey(self, username, key): + """ + Determine if a given key supplied by the client is acceptable for use + in authentication. You should override this method in server mode to + check the username and key and decide if you would accept a signature + made using this key. + + Return L{AUTH_FAILED} if the key is not accepted, + L{AUTH_SUCCESSFUL} if the key is accepted and completes the + authentication, or L{AUTH_PARTIALLY_SUCCESSFUL} if your + authentication is stateful, and this password is accepted for + authentication, but more authentication is required. (In this latter + case, L{get_allowed_auths} will be called to report to the client what + options it has for continuing the authentication.) + + Note that you don't have to actually verify any key signtature here. + If you're willing to accept the key, paramiko will do the work of + verifying the client's signature. + + The default implementation always returns L{AUTH_FAILED}. + + @param username: the username of the authenticating client + @type username: str + @param key: the key object provided by the client + @type key: L{PKey <pkey.PKey>} + @return: L{AUTH_FAILED} if the client can't authenticate + with this key; L{AUTH_SUCCESSFUL} if it can; + L{AUTH_PARTIALLY_SUCCESSFUL} if it can authenticate with + this key but must continue with authentication + @rtype: int + """ + return AUTH_FAILED + + def check_auth_interactive(self, username, submethods): + """ + Begin an interactive authentication challenge, if supported. You + should override this method in server mode if you want to support the + C{"keyboard-interactive"} auth type, which requires you to send a + series of questions for the client to answer. + + Return L{AUTH_FAILED} if this auth method isn't supported. Otherwise, + you should return an L{InteractiveQuery} object containing the prompts + and instructions for the user. The response will be sent via a call + to L{check_auth_interactive_response}. + + The default implementation always returns L{AUTH_FAILED}. + + @param username: the username of the authenticating client + @type username: str + @param submethods: a comma-separated list of methods preferred by the + client (usually empty) + @type submethods: str + @return: L{AUTH_FAILED} if this auth method isn't supported; otherwise + an object containing queries for the user + @rtype: int or L{InteractiveQuery} + """ + return AUTH_FAILED + + def check_auth_interactive_response(self, responses): + """ + Continue or finish an interactive authentication challenge, if + supported. You should override this method in server mode if you want + to support the C{"keyboard-interactive"} auth type. + + Return L{AUTH_FAILED} if the responses are not accepted, + L{AUTH_SUCCESSFUL} if the responses are accepted and complete + the authentication, or L{AUTH_PARTIALLY_SUCCESSFUL} if your + authentication is stateful, and this set of responses is accepted for + authentication, but more authentication is required. (In this latter + case, L{get_allowed_auths} will be called to report to the client what + options it has for continuing the authentication.) + + If you wish to continue interactive authentication with more questions, + you may return an L{InteractiveQuery} object, which should cause the + client to respond with more answers, calling this method again. This + cycle can continue indefinitely. + + The default implementation always returns L{AUTH_FAILED}. + + @param responses: list of responses from the client + @type responses: list(str) + @return: L{AUTH_FAILED} if the authentication fails; + L{AUTH_SUCCESSFUL} if it succeeds; + L{AUTH_PARTIALLY_SUCCESSFUL} if the interactive auth is + successful, but authentication must continue; otherwise an object + containing queries for the user + @rtype: int or L{InteractiveQuery} + """ + return AUTH_FAILED + + def check_global_request(self, kind, msg): + """ + Handle a global request of the given C{kind}. This method is called + in server mode and client mode, whenever the remote host makes a global + request. If there are any arguments to the request, they will be in + C{msg}. + + There aren't any useful global requests defined, aside from port + forwarding, so usually this type of request is an extension to the + protocol. + + If the request was successful and you would like to return contextual + data to the remote host, return a tuple. Items in the tuple will be + sent back with the successful result. (Note that the items in the + tuple can only be strings, ints, longs, or bools.) + + The default implementation always returns C{False}, indicating that it + does not support any global requests. + + @param kind: the kind of global request being made. + @type kind: str + @param msg: any extra arguments to the request. + @type msg: L{Message} + @return: C{True} or a tuple of data if the request was granted; + C{False} otherwise. + @rtype: bool + """ + return False + + + ### Channel requests + + + def check_channel_pty_request(self, channel, term, width, height, pixelwidth, pixelheight, + modes): + """ + Determine if a pseudo-terminal of the given dimensions (usually + requested for shell access) can be provided on the given channel. + + The default implementation always returns C{False}. + + @param channel: the L{Channel} the pty request arrived on. + @type channel: L{Channel} + @param term: type of terminal requested (for example, C{"vt100"}). + @type term: str + @param width: width of screen in characters. + @type width: int + @param height: height of screen in characters. + @type height: int + @param pixelwidth: width of screen in pixels, if known (may be C{0} if + unknown). + @type pixelwidth: int + @param pixelheight: height of screen in pixels, if known (may be C{0} + if unknown). + @type pixelheight: int + @return: C{True} if the psuedo-terminal has been allocated; C{False} + otherwise. + @rtype: bool + """ + return False + + def check_channel_shell_request(self, channel): + """ + Determine if a shell will be provided to the client on the given + channel. If this method returns C{True}, the channel should be + connected to the stdin/stdout of a shell (or something that acts like + a shell). + + The default implementation always returns C{False}. + + @param channel: the L{Channel} the request arrived on. + @type channel: L{Channel} + @return: C{True} if this channel is now hooked up to a shell; C{False} + if a shell can't or won't be provided. + @rtype: bool + """ + return False + + def check_channel_exec_request(self, channel, command): + """ + Determine if a shell command will be executed for the client. If this + method returns C{True}, the channel should be connected to the stdin, + stdout, and stderr of the shell command. + + The default implementation always returns C{False}. + + @param channel: the L{Channel} the request arrived on. + @type channel: L{Channel} + @param command: the command to execute. + @type command: str + @return: C{True} if this channel is now hooked up to the stdin, + stdout, and stderr of the executing command; C{False} if the + command will not be executed. + @rtype: bool + + @since: 1.1 + """ + return False + + def check_channel_subsystem_request(self, channel, name): + """ + Determine if a requested subsystem will be provided to the client on + the given channel. If this method returns C{True}, all future I/O + through this channel will be assumed to be connected to the requested + subsystem. An example of a subsystem is C{sftp}. + + The default implementation checks for a subsystem handler assigned via + L{Transport.set_subsystem_handler}. + If one has been set, the handler is invoked and this method returns + C{True}. Otherwise it returns C{False}. + + @note: Because the default implementation uses the L{Transport} to + identify valid subsystems, you probably won't need to override this + method. + + @param channel: the L{Channel} the pty request arrived on. + @type channel: L{Channel} + @param name: name of the requested subsystem. + @type name: str + @return: C{True} if this channel is now hooked up to the requested + subsystem; C{False} if that subsystem can't or won't be provided. + @rtype: bool + """ + handler_class, larg, kwarg = channel.get_transport()._get_subsystem_handler(name) + if handler_class is None: + return False + handler = handler_class(channel, name, self, *larg, **kwarg) + handler.start() + return True + + def check_channel_window_change_request(self, channel, width, height, pixelwidth, pixelheight): + """ + Determine if the pseudo-terminal on the given channel can be resized. + This only makes sense if a pty was previously allocated on it. + + The default implementation always returns C{False}. + + @param channel: the L{Channel} the pty request arrived on. + @type channel: L{Channel} + @param width: width of screen in characters. + @type width: int + @param height: height of screen in characters. + @type height: int + @param pixelwidth: width of screen in pixels, if known (may be C{0} if + unknown). + @type pixelwidth: int + @param pixelheight: height of screen in pixels, if known (may be C{0} + if unknown). + @type pixelheight: int + @return: C{True} if the terminal was resized; C{False} if not. + @rtype: bool + """ + return False + + +class SubsystemHandler (threading.Thread): + """ + Handler for a subsytem in server mode. If you create a subclass of this + class and pass it to + L{Transport.set_subsystem_handler}, + an object of this + class will be created for each request for this subsystem. Each new object + will be executed within its own new thread by calling L{start_subsystem}. + When that method completes, the channel is closed. + + For example, if you made a subclass C{MP3Handler} and registered it as the + handler for subsystem C{"mp3"}, then whenever a client has successfully + authenticated and requests subsytem C{"mp3"}, an object of class + C{MP3Handler} will be created, and L{start_subsystem} will be called on + it from a new thread. + + @since: ivysaur + """ + def __init__(self, channel, name, server): + """ + Create a new handler for a channel. This is used by L{ServerInterface} + to start up a new handler when a channel requests this subsystem. You + don't need to override this method, but if you do, be sure to pass the + C{channel} and C{name} parameters through to the original C{__init__} + method here. + + @param channel: the channel associated with this subsystem request. + @type channel: L{Channel} + @param name: name of the requested subsystem. + @type name: str + @param server: the server object for the session that started this + subsystem + @type server: L{ServerInterface} + """ + threading.Thread.__init__(self, target=self._run) + self.__channel = channel + self.__transport = channel.get_transport() + self.__name = name + self.__server = server + + def get_server(self): + """ + Return the L{ServerInterface} object associated with this channel and + subsystem. + + @rtype: L{ServerInterface} + """ + return self.__server + + def _run(self): + try: + self.__transport._log(DEBUG, 'Starting handler for subsystem %s' % self.__name) + self.start_subsystem(self.__name, self.__transport, self.__channel) + except Exception, e: + self.__transport._log(ERROR, 'Exception in subsystem handler for "%s": %s' % + (self.__name, str(e))) + self.__transport._log(ERROR, util.tb_strings()) + try: + self.finish_subsystem() + except: + pass + + def start_subsystem(self, name, transport, channel): + """ + Process an ssh subsystem in server mode. This method is called on a + new object (and in a new thread) for each subsystem request. It is + assumed that all subsystem logic will take place here, and when the + subsystem is finished, this method will return. After this method + returns, the channel is closed. + + The combination of C{transport} and C{channel} are unique; this handler + corresponds to exactly one L{Channel} on one L{Transport}. + + @note: It is the responsibility of this method to exit if the + underlying L{Transport} is closed. This can be done by checking + L{Transport.is_active} or noticing an EOF + on the L{Channel}. If this method loops forever without checking + for this case, your python interpreter may refuse to exit because + this thread will still be running. + + @param name: name of the requested subsystem. + @type name: str + @param transport: the server-mode L{Transport}. + @type transport: L{Transport} + @param channel: the channel associated with this subsystem request. + @type channel: L{Channel} + """ + pass + + def finish_subsystem(self): + """ + Perform any cleanup at the end of a subsystem. The default + implementation just closes the channel. + + @since: 1.1 + """ + self.__channel.close() diff --git a/paramiko/sftp.py b/paramiko/sftp.py new file mode 100644 index 0000000..58d7103 --- /dev/null +++ b/paramiko/sftp.py @@ -0,0 +1,168 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +import socket +import struct + +from paramiko.common import * +from paramiko import util +from paramiko.channel import Channel +from paramiko.message import Message + + +CMD_INIT, CMD_VERSION, CMD_OPEN, CMD_CLOSE, CMD_READ, CMD_WRITE, CMD_LSTAT, CMD_FSTAT, \ + CMD_SETSTAT, CMD_FSETSTAT, CMD_OPENDIR, CMD_READDIR, CMD_REMOVE, CMD_MKDIR, \ + CMD_RMDIR, CMD_REALPATH, CMD_STAT, CMD_RENAME, CMD_READLINK, CMD_SYMLINK \ + = range(1, 21) +CMD_STATUS, CMD_HANDLE, CMD_DATA, CMD_NAME, CMD_ATTRS = range(101, 106) +CMD_EXTENDED, CMD_EXTENDED_REPLY = range(200, 202) + +SFTP_OK = 0 +SFTP_EOF, SFTP_NO_SUCH_FILE, SFTP_PERMISSION_DENIED, SFTP_FAILURE, SFTP_BAD_MESSAGE, \ + SFTP_NO_CONNECTION, SFTP_CONNECTION_LOST, SFTP_OP_UNSUPPORTED = range(1, 9) + +SFTP_DESC = [ 'Success', + 'End of file', + 'No such file', + 'Permission denied', + 'Failure', + 'Bad message', + 'No connection', + 'Connection lost', + 'Operation unsupported' ] + +SFTP_FLAG_READ = 0x1 +SFTP_FLAG_WRITE = 0x2 +SFTP_FLAG_APPEND = 0x4 +SFTP_FLAG_CREATE = 0x8 +SFTP_FLAG_TRUNC = 0x10 +SFTP_FLAG_EXCL = 0x20 + +_VERSION = 3 + + +# for debugging +CMD_NAMES = { + CMD_INIT: 'init', + CMD_VERSION: 'version', + CMD_OPEN: 'open', + CMD_CLOSE: 'close', + CMD_READ: 'read', + CMD_WRITE: 'write', + CMD_LSTAT: 'lstat', + CMD_FSTAT: 'fstat', + CMD_SETSTAT: 'setstat', + CMD_FSETSTAT: 'fsetstat', + CMD_OPENDIR: 'opendir', + CMD_READDIR: 'readdir', + CMD_REMOVE: 'remove', + CMD_MKDIR: 'mkdir', + CMD_RMDIR: 'rmdir', + CMD_REALPATH: 'realpath', + CMD_STAT: 'stat', + CMD_RENAME: 'rename', + CMD_READLINK: 'readlink', + CMD_SYMLINK: 'symlink', + CMD_STATUS: 'status', + CMD_HANDLE: 'handle', + CMD_DATA: 'data', + CMD_NAME: 'name', + CMD_ATTRS: 'attrs', + CMD_EXTENDED: 'extended', + CMD_EXTENDED_REPLY: 'extended_reply' + } + + +class SFTPError (Exception): + pass + + +class BaseSFTP (object): + def __init__(self): + self.logger = util.get_logger('paramiko.sftp') + self.sock = None + self.ultra_debug = False + + + ### internals... + + + def _send_version(self): + self._send_packet(CMD_INIT, struct.pack('>I', _VERSION)) + t, data = self._read_packet() + if t != CMD_VERSION: + raise SFTPError('Incompatible sftp protocol') + version = struct.unpack('>I', data[:4])[0] + # if version != _VERSION: + # raise SFTPError('Incompatible sftp protocol') + return version + + def _send_server_version(self): + # advertise that we support "check-file" + extension_pairs = [ 'check-file', 'md5,sha1' ] + msg = Message() + msg.add_int(_VERSION) + msg.add(*extension_pairs) + self._send_packet(CMD_VERSION, str(msg)) + t, data = self._read_packet() + if t != CMD_INIT: + raise SFTPError('Incompatible sftp protocol') + version = struct.unpack('>I', data[:4])[0] + return version + + def _log(self, level, msg): + if issubclass(type(msg), list): + for m in msg: + self.logger.log(level, m) + else: + self.logger.log(level, msg) + + def _write_all(self, out): + while len(out) > 0: + n = self.sock.send(out) + if n <= 0: + raise EOFError() + if n == len(out): + return + out = out[n:] + return + + def _read_all(self, n): + out = '' + while n > 0: + x = self.sock.recv(n) + if len(x) == 0: + raise EOFError() + out += x + n -= len(x) + return out + + def _send_packet(self, t, packet): + out = struct.pack('>I', len(packet) + 1) + chr(t) + packet + if self.ultra_debug: + self._log(DEBUG, util.format_binary(out, 'OUT: ')) + self._write_all(out) + + def _read_packet(self): + size = struct.unpack('>I', self._read_all(4))[0] + data = self._read_all(size) + if self.ultra_debug: + self._log(DEBUG, util.format_binary(data, 'IN: ')); + if size > 0: + return ord(data[0]), data[1:] + return 0, '' diff --git a/paramiko/sftp_attr.py b/paramiko/sftp_attr.py new file mode 100644 index 0000000..eae7c99 --- /dev/null +++ b/paramiko/sftp_attr.py @@ -0,0 +1,208 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +import stat +import time +from paramiko.common import * +from paramiko.sftp import * + + +class SFTPAttributes (object): + """ + Representation of the attributes of a file (or proxied file) for SFTP in + client or server mode. It attemps to mirror the object returned by + C{os.stat} as closely as possible, so it may have the following fields, + with the same meanings as those returned by an C{os.stat} object: + - st_size + - st_uid + - st_gid + - st_mode + - st_atime + - st_mtime + + Because SFTP allows flags to have other arbitrary named attributes, these + are stored in a dict named C{attr}. Occasionally, the filename is also + stored, in C{filename}. + """ + + FLAG_SIZE = 1 + FLAG_UIDGID = 2 + FLAG_PERMISSIONS = 4 + FLAG_AMTIME = 8 + FLAG_EXTENDED = 0x80000000L + + def __init__(self): + """ + Create a new (empty) SFTPAttributes object. All fields will be empty. + """ + self._flags = 0 + self.attr = {} + + def from_stat(cls, obj, filename=None): + """ + Create an SFTPAttributes object from an existing C{stat} object (an + object returned by C{os.stat}). + + @param obj: an object returned by C{os.stat} (or equivalent). + @type obj: object + @param filename: the filename associated with this file. + @type filename: str + @return: new L{SFTPAttributes} object with the same attribute fields. + @rtype: L{SFTPAttributes} + """ + attr = cls() + attr.st_size = obj.st_size + attr.st_uid = obj.st_uid + attr.st_gid = obj.st_gid + attr.st_mode = obj.st_mode + attr.st_atime = obj.st_atime + attr.st_mtime = obj.st_mtime + if filename is not None: + attr.filename = filename + return attr + from_stat = classmethod(from_stat) + + def __repr__(self): + return '<SFTPAttributes: %s>' % self._debug_str() + + def __str__(self): + return self._debug_str() + + + ### internals... + + + def _from_msg(cls, msg, filename=None): + attr = cls() + attr._unpack(msg) + if filename is not None: + attr.filename = filename + return attr + _from_msg = classmethod(_from_msg) + + def _unpack(self, msg): + self._flags = msg.get_int() + if self._flags & self.FLAG_SIZE: + self.st_size = msg.get_int64() + if self._flags & self.FLAG_UIDGID: + self.st_uid = msg.get_int() + self.st_gid = msg.get_int() + if self._flags & self.FLAG_PERMISSIONS: + self.st_mode = msg.get_int() + if self._flags & self.FLAG_AMTIME: + self.st_atime = msg.get_int() + self.st_mtime = msg.get_int() + if self._flags & self.FLAG_EXTENDED: + count = msg.get_int() + for i in range(count): + self.attr[msg.get_string()] = msg.get_string() + + def _pack(self, msg): + self._flags = 0 + if hasattr(self, 'st_size'): + self._flags |= self.FLAG_SIZE + if hasattr(self, 'st_uid') or hasattr(self, 'st_gid'): + self._flags |= self.FLAG_UIDGID + if hasattr(self, 'st_mode'): + self._flags |= self.FLAG_PERMISSIONS + if hasattr(self, 'st_atime') or hasattr(self, 'st_mtime'): + self._flags |= self.FLAG_AMTIME + if len(self.attr) > 0: + self._flags |= self.FLAG_EXTENDED + msg.add_int(self._flags) + if self._flags & self.FLAG_SIZE: + msg.add_int64(self.st_size) + if self._flags & self.FLAG_UIDGID: + msg.add_int(getattr(self, 'st_uid', 0)) + msg.add_int(getattr(self, 'st_gid', 0)) + if self._flags & self.FLAG_PERMISSIONS: + msg.add_int(self.st_mode) + if self._flags & self.FLAG_AMTIME: + msg.add_int(getattr(self, 'st_atime', 0)) + msg.add_int(getattr(self, 'st_mtime', 0)) + if self._flags & self.FLAG_EXTENDED: + msg.add_int(len(self.attr)) + for key, val in self.attr.iteritems(): + msg.add_string(key) + msg.add_string(val) + return + + def _debug_str(self): + out = '[ ' + if hasattr(self, 'st_size'): + out += 'size=%d ' % self.st_size + if hasattr(self, 'st_uid') or hasattr(self, 'st_gid'): + out += 'uid=%d gid=%d ' % (getattr(self, 'st_uid', 0), getattr(self, 'st_gid', 0)) + if hasattr(self, 'st_mode'): + out += 'mode=' + oct(self.st_mode) + ' ' + if hasattr(self, 'st_atime') or hasattr(self, 'st_mtime'): + out += 'atime=%d mtime=%d ' % (getattr(self, 'st_atime', 0), + getattr(self, 'st_mtime', 0)) + for k, v in self.attr.iteritems(): + out += '"%s"=%r ' % (str(k), v) + out += ']' + return out + + def _rwx(n, suid, sticky=False): + if suid: + suid = 2 + out = '-r'[n >> 2] + '-w'[(n >> 1) & 1] + if sticky: + out += '-xTt'[suid + (n & 1)] + else: + out += '-xSs'[suid + (n & 1)] + return out + _rwx = staticmethod(_rwx) + + def __str__(self): + "create a unix-style long description of the file (like ls -l)" + if hasattr(self, 'st_mode'): + kind = stat.S_IFMT(self.st_mode) + if kind == stat.S_IFIFO: + ks = 'p' + elif kind == stat.S_IFCHR: + ks = 'c' + elif kind == stat.S_IFDIR: + ks = 'd' + elif kind == stat.S_IFBLK: + ks = 'b' + elif kind == stat.S_IFREG: + ks = '-' + elif kind == stat.S_IFLNK: + ks = 'l' + elif kind == stat.S_IFSOCK: + ks = 's' + else: + ks = '?' + ks += self._rwx((self.st_mode & 0700) >> 6, self.st_mode & stat.S_ISUID) + ks += self._rwx((self.st_mode & 070) >> 3, self.st_mode & stat.S_ISGID) + ks += self._rwx(self.st_mode & 7, self.st_mode & stat.S_ISVTX, True) + else: + ks = '?---------' + uid = getattr(self, 'st_uid', -1) + gid = getattr(self, 'st_gid', -1) + size = getattr(self, 'st_size', -1) + mtime = getattr(self, 'st_mtime', 0) + # compute display date + if abs(time.time() - mtime) > 15552000: + # (15552000 = 6 months) + datestr = time.strftime('%d %b %Y', time.localtime(mtime)) + else: + datestr = time.strftime('%d %b %H:%M', time.localtime(mtime)) + filename = getattr(self, 'filename', '?') + return '%s 1 %-8d %-8d %8d %-12s %s' % (ks, uid, gid, size, datestr, filename) diff --git a/paramiko/sftp_client.py b/paramiko/sftp_client.py new file mode 100644 index 0000000..2fe89e9 --- /dev/null +++ b/paramiko/sftp_client.py @@ -0,0 +1,618 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Client-mode SFTP support. +""" + +import errno +import os +import threading +import weakref +from paramiko.sftp import * +from paramiko.sftp_attr import SFTPAttributes +from paramiko.sftp_file import SFTPFile + + +def _to_unicode(s): + "if a str is not ascii, decode its utf8 into unicode" + try: + return s.encode('ascii') + except: + return s.decode('utf-8') + + +class SFTPClient (BaseSFTP): + """ + SFTP client object. C{SFTPClient} is used to open an sftp session across + an open ssh L{Transport} and do remote file operations. + """ + + def __init__(self, sock): + """ + Create an SFTP client from an existing L{Channel}. The channel + should already have requested the C{"sftp"} subsystem. + + An alternate way to create an SFTP client context is by using + L{from_transport}. + + @param sock: an open L{Channel} using the C{"sftp"} subsystem. + @type sock: L{Channel} + """ + BaseSFTP.__init__(self) + self.sock = sock + self.ultra_debug = False + self.request_number = 1 + # lock for request_number + self._lock = threading.Lock() + self._cwd = None + # request # -> SFTPFile + self._expecting = weakref.WeakValueDictionary() + if type(sock) is Channel: + # override default logger + transport = self.sock.get_transport() + self.logger = util.get_logger(transport.get_log_channel() + '.' + + self.sock.get_name() + '.sftp') + self.ultra_debug = transport.get_hexdump() + self._send_version() + + def __del__(self): + self.close() + + def from_transport(selfclass, t): + """ + Create an SFTP client channel from an open L{Transport}. + + @param t: an open L{Transport} which is already authenticated. + @type t: L{Transport} + @return: a new L{SFTPClient} object, referring to an sftp session + (channel) across the transport. + @rtype: L{SFTPClient} + """ + chan = t.open_session() + if chan is None: + return None + if not chan.invoke_subsystem('sftp'): + raise SFTPError('Failed to invoke sftp subsystem') + return selfclass(chan) + from_transport = classmethod(from_transport) + + def close(self): + """ + Close the SFTP session and its underlying channel. + + @since: 1.4 + """ + self.sock.close() + + def listdir(self, path='.'): + """ + Return a list containing the names of the entries in the given C{path}. + The list is in arbitrary order. It does not include the special + entries C{'.'} and C{'..'} even if they are present in the folder. + This method is meant to mirror C{os.listdir} as closely as possible. + For a list of full L{SFTPAttributes} objects, see L{listdir_attr}. + + @param path: path to list (defaults to C{'.'}) + @type path: str + @return: list of filenames + @rtype: list of str + """ + return [f.filename for f in self.listdir_attr(path)] + + def listdir_attr(self, path='.'): + """ + Return a list containing L{SFTPAttributes} objects corresponding to + files in the given C{path}. The list is in arbitrary order. It does + not include the special entries C{'.'} and C{'..'} even if they are + present in the folder. + + @param path: path to list (defaults to C{'.'}) + @type path: str + @return: list of attributes + @rtype: list of L{SFTPAttributes} + + @since: 1.2 + """ + path = self._adjust_cwd(path) + t, msg = self._request(CMD_OPENDIR, path) + if t != CMD_HANDLE: + raise SFTPError('Expected handle') + handle = msg.get_string() + filelist = [] + while True: + try: + t, msg = self._request(CMD_READDIR, handle) + except EOFError, e: + # done with handle + break + if t != CMD_NAME: + raise SFTPError('Expected name response') + count = msg.get_int() + for i in range(count): + filename = _to_unicode(msg.get_string()) + longname = _to_unicode(msg.get_string()) + attr = SFTPAttributes._from_msg(msg, filename) + if (filename != '.') and (filename != '..'): + filelist.append(attr) + self._request(CMD_CLOSE, handle) + return filelist + + def file(self, filename, mode='r', bufsize=-1): + """ + Open a file on the remote server. The arguments are the same as for + python's built-in C{file} (aka C{open}). A file-like object is + returned, which closely mimics the behavior of a normal python file + object. + + The mode indicates how the file is to be opened: C{'r'} for reading, + C{'w'} for writing (truncating an existing file), C{'a'} for appending, + C{'r+'} for reading/writing, C{'w+'} for reading/writing (truncating an + existing file), C{'a+'} for reading/appending. The python C{'b'} flag + is ignored, since SSH treats all files as binary. The C{'U'} flag is + supported in a compatible way. + + Since 1.5.2, an C{'x'} flag indicates that the operation should only + succeed if the file was created and did not previously exist. This has + no direct mapping to python's file flags, but is commonly known as the + C{O_EXCL} flag in posix. + + The file will be buffered in standard python style by default, but + can be altered with the C{bufsize} parameter. C{0} turns off + buffering, C{1} uses line buffering, and any number greater than 1 + (C{>1}) uses that specific buffer size. + + @param filename: name of the file to open. + @type filename: string + @param mode: mode (python-style) to open in. + @type mode: string + @param bufsize: desired buffering (-1 = default buffer size) + @type bufsize: int + @return: a file object representing the open file. + @rtype: SFTPFile + + @raise IOError: if the file could not be opened. + """ + filename = self._adjust_cwd(filename) + imode = 0 + if ('r' in mode) or ('+' in mode): + imode |= SFTP_FLAG_READ + if ('w' in mode) or ('+' in mode) or ('a' in mode): + imode |= SFTP_FLAG_WRITE + if ('w' in mode): + imode |= SFTP_FLAG_CREATE | SFTP_FLAG_TRUNC + if ('a' in mode): + imode |= SFTP_FLAG_CREATE | SFTP_FLAG_APPEND + if ('x' in mode): + imode |= SFTP_FLAG_CREATE | SFTP_FLAG_EXCL + attrblock = SFTPAttributes() + t, msg = self._request(CMD_OPEN, filename, imode, attrblock) + if t != CMD_HANDLE: + raise SFTPError('Expected handle') + handle = msg.get_string() + return SFTPFile(self, handle, mode, bufsize) + + # python has migrated toward file() instead of open(). + # and really, that's more easily identifiable. + open = file + + def remove(self, path): + """ + Remove the file at the given path. + + @param path: path (absolute or relative) of the file to remove. + @type path: string + + @raise IOError: if the path refers to a folder (directory). Use + L{rmdir} to remove a folder. + """ + path = self._adjust_cwd(path) + self._request(CMD_REMOVE, path) + + unlink = remove + + def rename(self, oldpath, newpath): + """ + Rename a file or folder from C{oldpath} to C{newpath}. + + @param oldpath: existing name of the file or folder. + @type oldpath: string + @param newpath: new name for the file or folder. + @type newpath: string + + @raise IOError: if C{newpath} is a folder, or something else goes + wrong. + """ + oldpath = self._adjust_cwd(oldpath) + newpath = self._adjust_cwd(newpath) + self._request(CMD_RENAME, oldpath, newpath) + + def mkdir(self, path, mode=0777): + """ + Create a folder (directory) named C{path} with numeric mode C{mode}. + The default mode is 0777 (octal). On some systems, mode is ignored. + Where it is used, the current umask value is first masked out. + + @param path: name of the folder to create. + @type path: string + @param mode: permissions (posix-style) for the newly-created folder. + @type mode: int + """ + path = self._adjust_cwd(path) + attr = SFTPAttributes() + attr.st_mode = mode + self._request(CMD_MKDIR, path, attr) + + def rmdir(self, path): + """ + Remove the folder named C{path}. + + @param path: name of the folder to remove. + @type path: string + """ + path = self._adjust_cwd(path) + self._request(CMD_RMDIR, path) + + def stat(self, path): + """ + Retrieve information about a file on the remote system. The return + value is an object whose attributes correspond to the attributes of + python's C{stat} structure as returned by C{os.stat}, except that it + contains fewer fields. An SFTP server may return as much or as little + info as it wants, so the results may vary from server to server. + + Unlike a python C{stat} object, the result may not be accessed as a + tuple. This is mostly due to the author's slack factor. + + The fields supported are: C{st_mode}, C{st_size}, C{st_uid}, C{st_gid}, + C{st_atime}, and C{st_mtime}. + + @param path: the filename to stat. + @type path: string + @return: an object containing attributes about the given file. + @rtype: SFTPAttributes + """ + path = self._adjust_cwd(path) + t, msg = self._request(CMD_STAT, path) + if t != CMD_ATTRS: + raise SFTPError('Expected attributes') + return SFTPAttributes._from_msg(msg) + + def lstat(self, path): + """ + Retrieve information about a file on the remote system, without + following symbolic links (shortcuts). This otherwise behaves exactly + the same as L{stat}. + + @param path: the filename to stat. + @type path: string + @return: an object containing attributes about the given file. + @rtype: SFTPAttributes + """ + path = self._adjust_cwd(path) + t, msg = self._request(CMD_LSTAT, path) + if t != CMD_ATTRS: + raise SFTPError('Expected attributes') + return SFTPAttributes._from_msg(msg) + + def symlink(self, source, dest): + """ + Create a symbolic link (shortcut) of the C{source} path at + C{destination}. + + @param source: path of the original file. + @type source: string + @param dest: path of the newly created symlink. + @type dest: string + """ + dest = self._adjust_cwd(dest) + if type(source) is unicode: + source = source.encode('utf-8') + self._request(CMD_SYMLINK, source, dest) + + def chmod(self, path, mode): + """ + Change the mode (permissions) of a file. The permissions are + unix-style and identical to those used by python's C{os.chmod} + function. + + @param path: path of the file to change the permissions of. + @type path: string + @param mode: new permissions. + @type mode: int + """ + path = self._adjust_cwd(path) + attr = SFTPAttributes() + attr.st_mode = mode + self._request(CMD_SETSTAT, path, attr) + + def chown(self, path, uid, gid): + """ + Change the owner (C{uid}) and group (C{gid}) of a file. As with + python's C{os.chown} function, you must pass both arguments, so if you + only want to change one, use L{stat} first to retrieve the current + owner and group. + + @param path: path of the file to change the owner and group of. + @type path: string + @param uid: new owner's uid + @type uid: int + @param gid: new group id + @type gid: int + """ + path = self._adjust_cwd(path) + attr = SFTPAttributes() + attr.st_uid, attr.st_gid = uid, gid + self._request(CMD_SETSTAT, path, attr) + + def utime(self, path, times): + """ + Set the access and modified times of the file specified by C{path}. If + C{times} is C{None}, then the file's access and modified times are set + to the current time. Otherwise, C{times} must be a 2-tuple of numbers, + of the form C{(atime, mtime)}, which is used to set the access and + modified times, respectively. This bizarre API is mimicked from python + for the sake of consistency -- I apologize. + + @param path: path of the file to modify. + @type path: string + @param times: C{None} or a tuple of (access time, modified time) in + standard internet epoch time (seconds since 01 January 1970 GMT). + @type times: tuple of int + """ + path = self._adjust_cwd(path) + if times is None: + times = (time.time(), time.time()) + attr = SFTPAttributes() + attr.st_atime, attr.st_mtime = times + self._request(CMD_SETSTAT, path, attr) + + def readlink(self, path): + """ + Return the target of a symbolic link (shortcut). You can use + L{symlink} to create these. The result may be either an absolute or + relative pathname. + + @param path: path of the symbolic link file. + @type path: str + @return: target path. + @rtype: str + """ + path = self._adjust_cwd(path) + t, msg = self._request(CMD_READLINK, path) + if t != CMD_NAME: + raise SFTPError('Expected name response') + count = msg.get_int() + if count == 0: + return None + if count != 1: + raise SFTPError('Readlink returned %d results' % count) + return _to_unicode(msg.get_string()) + + def normalize(self, path): + """ + Return the normalized path (on the server) of a given path. This + can be used to quickly resolve symbolic links or determine what the + server is considering to be the "current folder" (by passing C{'.'} + as C{path}). + + @param path: path to be normalized. + @type path: str + @return: normalized form of the given path. + @rtype: str + + @raise IOError: if the path can't be resolved on the server + """ + path = self._adjust_cwd(path) + t, msg = self._request(CMD_REALPATH, path) + if t != CMD_NAME: + raise SFTPError('Expected name response') + count = msg.get_int() + if count != 1: + raise SFTPError('Realpath returned %d results' % count) + return _to_unicode(msg.get_string()) + + def chdir(self, path): + """ + Change the "current directory" of this SFTP session. Since SFTP + doesn't really have the concept of a current working directory, this + is emulated by paramiko. Once you use this method to set a working + directory, all operations on this SFTPClient object will be relative + to that path. + + @param path: new current working directory + @type path: str + + @raise IOError: if the requested path doesn't exist on the server + + @since: 1.4 + """ + self._cwd = self.normalize(path) + + def getcwd(self): + """ + Return the "current working directory" for this SFTP session, as + emulated by paramiko. If no directory has been set with L{chdir}, + this method will return C{None}. + + @return: the current working directory on the server, or C{None} + @rtype: str + + @since: 1.4 + """ + return self._cwd + + def put(self, localpath, remotepath): + """ + Copy a local file (C{localpath}) to the SFTP server as C{remotepath}. + Any exception raised by operations will be passed through. This + method is primarily provided as a convenience. + + The SFTP operations use pipelining for speed. + + @param localpath: the local file to copy + @type localpath: str + @param remotepath: the destination path on the SFTP server + @type remotepath: str + + @since: 1.4 + """ + fl = file(localpath, 'rb') + fr = self.file(remotepath, 'wb') + fr.set_pipelined(True) + size = 0 + while True: + data = fl.read(32768) + if len(data) == 0: + break + fr.write(data) + size += len(data) + fl.close() + fr.close() + s = self.stat(remotepath) + if s.st_size != size: + raise IOError('size mismatch in put! %d != %d' % (s.st_size, size)) + + def get(self, remotepath, localpath): + """ + Copy a remote file (C{remotepath}) from the SFTP server to the local + host as C{localpath}. Any exception raised by operations will be + passed through. This method is primarily provided as a convenience. + + @param remotepath: the remote file to copy + @type remotepath: str + @param localpath: the destination path on the local host + @type localpath: str + + @since: 1.4 + """ + fr = self.file(remotepath, 'rb') + fr.prefetch() + fl = file(localpath, 'wb') + size = 0 + while True: + data = fr.read(32768) + if len(data) == 0: + break + fl.write(data) + size += len(data) + fl.close() + fr.close() + s = os.stat(localpath) + if s.st_size != size: + raise IOError('size mismatch in get! %d != %d' % (s.st_size, size)) + + + ### internals... + + + def _request(self, t, *arg): + num = self._async_request(type(None), t, *arg) + return self._read_response(num) + + def _async_request(self, fileobj, t, *arg): + # this method may be called from other threads (prefetch) + self._lock.acquire() + try: + msg = Message() + msg.add_int(self.request_number) + for item in arg: + if type(item) is int: + msg.add_int(item) + elif type(item) is long: + msg.add_int64(item) + elif type(item) is str: + msg.add_string(item) + elif type(item) is SFTPAttributes: + item._pack(msg) + else: + raise Exception('unknown type for %r type %r' % (item, type(item))) + num = self.request_number + self._expecting[num] = fileobj + self._send_packet(t, str(msg)) + self.request_number += 1 + finally: + self._lock.release() + return num + + def _read_response(self, waitfor=None): + while True: + t, data = self._read_packet() + msg = Message(data) + num = msg.get_int() + if num not in self._expecting: + # might be response for a file that was closed before responses came back + self._log(DEBUG, 'Unexpected response #%d' % (num,)) + if waitfor is None: + # just doing a single check + return + continue + fileobj = self._expecting[num] + del self._expecting[num] + if num == waitfor: + # synchronous + if t == CMD_STATUS: + self._convert_status(msg) + return t, msg + if fileobj is not type(None): + fileobj._async_response(t, msg) + if waitfor is None: + # just doing a single check + return + + def _finish_responses(self, fileobj): + while fileobj in self._expecting.values(): + self._read_response() + fileobj._check_exception() + + def _convert_status(self, msg): + """ + Raises EOFError or IOError on error status; otherwise does nothing. + """ + code = msg.get_int() + text = msg.get_string() + if code == SFTP_OK: + return + elif code == SFTP_EOF: + raise EOFError(text) + elif code == SFTP_NO_SUCH_FILE: + # clever idea from john a. meinel: map the error codes to errno + raise IOError(errno.ENOENT, text) + elif code == SFTP_PERMISSION_DENIED: + raise IOError(errno.EACCES, text) + else: + raise IOError(text) + + def _adjust_cwd(self, path): + """ + Return an adjusted path if we're emulating a "current working + directory" for the server. + """ + if type(path) is unicode: + path = path.encode('utf-8') + if self._cwd is None: + return path + if (len(path) > 0) and (path[0] == '/'): + # absolute path + return path + return self._cwd + '/' + path + + +class SFTP (SFTPClient): + "an alias for L{SFTPClient} for backwards compatability" + pass diff --git a/paramiko/sftp_file.py b/paramiko/sftp_file.py new file mode 100644 index 0000000..f224f02 --- /dev/null +++ b/paramiko/sftp_file.py @@ -0,0 +1,307 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{SFTPFile} +""" + +import threading +from paramiko.common import * +from paramiko.sftp import * +from paramiko.file import BufferedFile +from paramiko.sftp_attr import SFTPAttributes + + +class SFTPFile (BufferedFile): + """ + Proxy object for a file on the remote server, in client mode SFTP. + """ + + # Some sftp servers will choke if you send read/write requests larger than + # this size. + MAX_REQUEST_SIZE = 32768 + + def __init__(self, sftp, handle, mode='r', bufsize=-1): + BufferedFile.__init__(self) + self.sftp = sftp + self.handle = handle + BufferedFile._set_mode(self, mode, bufsize) + self.pipelined = False + self._prefetching = False + self._saved_exception = None + + def __del__(self): + self.close(_async=True) + + def close(self, _async=False): + # We allow double-close without signaling an error, because real + # Python file objects do. However, we must protect against actually + # sending multiple CMD_CLOSE packets, because after we close our + # handle, the same handle may be re-allocated by the server, and we + # may end up mysteriously closing some random other file. (This is + # especially important because we unconditionally call close() from + # __del__.) + if self._closed: + return + if self.pipelined: + self.sftp._finish_responses(self) + BufferedFile.close(self) + try: + if _async: + # GC'd file handle could be called from an arbitrary thread -- don't wait for a response + self.sftp._async_request(type(None), CMD_CLOSE, self.handle) + else: + self.sftp._request(CMD_CLOSE, self.handle) + except EOFError: + # may have outlived the Transport connection + pass + except IOError: + # may have outlived the Transport connection + pass + + def _read_prefetch(self, size): + # while not closed, and haven't fetched past the current position, and haven't reached EOF... + while (self._prefetch_so_far <= self._realpos) and \ + (self._prefetch_so_far < self._prefetch_size) and not self._closed: + self.sftp._read_response() + self._check_exception() + k = self._prefetch_data.keys() + k.sort() + while (len(k) > 0) and (k[0] + len(self._prefetch_data[k[0]]) <= self._realpos): + # done with that block + del self._prefetch_data[k[0]] + k.pop(0) + if len(k) == 0: + self._prefetching = False + return '' + assert k[0] <= self._realpos + buf_offset = self._realpos - k[0] + buf_length = len(self._prefetch_data[k[0]]) - buf_offset + return self._prefetch_data[k[0]][buf_offset : buf_offset + buf_length] + + def _read(self, size): + size = min(size, self.MAX_REQUEST_SIZE) + if self._prefetching: + return self._read_prefetch(size) + t, msg = self.sftp._request(CMD_READ, self.handle, long(self._realpos), int(size)) + if t != CMD_DATA: + raise SFTPError('Expected data') + return msg.get_string() + + def _write(self, data): + # may write less than requested if it would exceed max packet size + chunk = min(len(data), self.MAX_REQUEST_SIZE) + req = self.sftp._async_request(type(None), CMD_WRITE, self.handle, long(self._realpos), + str(data[:chunk])) + if not self.pipelined or self.sftp.sock.recv_ready(): + t, msg = self.sftp._read_response(req) + if t != CMD_STATUS: + raise SFTPError('Expected status') + # convert_status already called + return chunk + + def settimeout(self, timeout): + """ + Set a timeout on read/write operations on the underlying socket or + ssh L{Channel}. + + @see: L{Channel.settimeout} + @param timeout: seconds to wait for a pending read/write operation + before raising C{socket.timeout}, or C{None} for no timeout + @type timeout: float + """ + self.sftp.sock.settimeout(timeout) + + def gettimeout(self): + """ + Returns the timeout in seconds (as a float) associated with the socket + or ssh L{Channel} used for this file. + + @see: L{Channel.gettimeout} + @rtype: float + """ + return self.sftp.sock.gettimeout() + + def setblocking(self, blocking): + """ + Set blocking or non-blocking mode on the underiying socket or ssh + L{Channel}. + + @see: L{Channel.setblocking} + @param blocking: 0 to set non-blocking mode; non-0 to set blocking + mode. + @type blocking: int + """ + self.sftp.sock.setblocking(blocking) + + def seek(self, offset, whence=0): + self.flush() + if whence == self.SEEK_SET: + self._realpos = self._pos = offset + elif whence == self.SEEK_CUR: + self._pos += offset + self._realpos = self._pos + else: + self._realpos = self._pos = self._get_size() + offset + self._rbuffer = '' + + def stat(self): + """ + Retrieve information about this file from the remote system. This is + exactly like L{SFTP.stat}, except that it operates on an already-open + file. + + @return: an object containing attributes about this file. + @rtype: SFTPAttributes + """ + t, msg = self.sftp._request(CMD_FSTAT, self.handle) + if t != CMD_ATTRS: + raise SFTPError('Expected attributes') + return SFTPAttributes._from_msg(msg) + + def check(self, hash_algorithm, offset=0, length=0, block_size=0): + """ + Ask the server for a hash of a section of this file. This can be used + to verify a successful upload or download, or for various rsync-like + operations. + + The file is hashed from C{offset}, for C{length} bytes. If C{length} + is 0, the remainder of the file is hashed. Thus, if both C{offset} + and C{length} are zero, the entire file is hashed. + + Normally, C{block_size} will be 0 (the default), and this method will + return a byte string representing the requested hash (for example, a + string of length 16 for MD5, or 20 for SHA-1). If a non-zero + C{block_size} is given, each chunk of the file (from C{offset} to + C{offset + length}) of C{block_size} bytes is computed as a separate + hash. The hash results are all concatenated and returned as a single + string. + + For example, C{check('sha1', 0, 1024, 512)} will return a string of + length 40. The first 20 bytes will be the SHA-1 of the first 512 bytes + of the file, and the last 20 bytes will be the SHA-1 of the next 512 + bytes. + + @param hash_algorithm: the name of the hash algorithm to use (normally + C{"sha1"} or C{"md5"}) + @type hash_algorithm: str + @param offset: offset into the file to begin hashing (0 means to start + from the beginning) + @type offset: int or long + @param length: number of bytes to hash (0 means continue to the end of + the file) + @type length: int or long + @param block_size: number of bytes to hash per result (must not be less + than 256; 0 means to compute only one hash of the entire segment) + @type block_size: int + @return: string of bytes representing the hash of each block, + concatenated together + @rtype: str + + @note: Many (most?) servers don't support this extension yet. + + @raise IOError: if the server doesn't support the "check-file" + extension, or possibly doesn't support the hash algorithm + requested + + @since: 1.4 + """ + t, msg = self.sftp._request(CMD_EXTENDED, 'check-file', self.handle, + hash_algorithm, long(offset), long(length), block_size) + ext = msg.get_string() + alg = msg.get_string() + data = msg.get_remainder() + return data + + def set_pipelined(self, pipelined=True): + """ + Turn on/off the pipelining of write operations to this file. When + pipelining is on, paramiko won't wait for the server response after + each write operation. Instead, they're collected as they come in. + At the first non-write operation (including L{close}), all remaining + server responses are collected. This means that if there was an error + with one of your later writes, an exception might be thrown from + within L{close} instead of L{write}. + + By default, files are I{not} pipelined. + + @param pipelined: C{True} if pipelining should be turned on for this + file; C{False} otherwise + @type pipelined: bool + + @since: 1.5 + """ + self.pipelined = pipelined + + def prefetch(self): + """ + Pre-fetch the remaining contents of this file in anticipation of + future L{read} calls. If reading the entire file, pre-fetching can + dramatically improve the download speed by avoiding roundtrip latency. + The file's contents are incrementally buffered in a background thread. + + @since: 1.5.1 + """ + size = self.stat().st_size + # queue up async reads for the rest of the file + self._prefetching = True + self._prefetch_so_far = self._realpos + self._prefetch_size = size + self._prefetch_data = {} + t = threading.Thread(target=self._prefetch) + t.setDaemon(True) + t.start() + + def _prefetch(self): + n = self._realpos + size = self._prefetch_size + while n < size: + chunk = min(self.MAX_REQUEST_SIZE, size - n) + self.sftp._async_request(self, CMD_READ, self.handle, long(n), int(chunk)) + n += chunk + + + ### internals... + + + def _get_size(self): + try: + return self.stat().st_size + except: + return 0 + + def _async_response(self, t, msg): + if t == CMD_STATUS: + # save exception and re-raise it on next file operation + try: + self.sftp._convert_status(msg) + except Exception, x: + self._saved_exception = x + return + if t != CMD_DATA: + raise SFTPError('Expected data') + data = msg.get_string() + self._prefetch_data[self._prefetch_so_far] = data + self._prefetch_so_far += len(data) + + def _check_exception(self): + "if there's a saved exception, raise & clear it" + if self._saved_exception is not None: + x = self._saved_exception + self._saved_exception = None + raise x diff --git a/paramiko/sftp_handle.py b/paramiko/sftp_handle.py new file mode 100644 index 0000000..e1d93e9 --- /dev/null +++ b/paramiko/sftp_handle.py @@ -0,0 +1,188 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Abstraction of an SFTP file handle (for server mode). +""" + +import os + +from paramiko.common import * +from paramiko.sftp import * + + +class SFTPHandle (object): + """ + Abstract object representing a handle to an open file (or folder) in an + SFTP server implementation. Each handle has a string representation used + by the client to refer to the underlying file. + + Server implementations can (and should) subclass SFTPHandle to implement + features of a file handle, like L{stat} or L{chattr}. + """ + def __init__(self): + self.__name = None + # only for handles to folders: + self.__files = { } + self.__tell = None + + def close(self): + """ + When a client closes a file, this method is called on the handle. + Normally you would use this method to close the underlying OS level + file object(s). + + The default implementation checks for attributes on C{self} named + C{readfile} and/or C{writefile}, and if either or both are present, + their C{close()} methods are called. This means that if you are + using the default implementations of L{read} and L{write}, this + method's default implementation should be fine also. + """ + readfile = getattr(self, 'readfile', None) + if readfile is not None: + readfile.close() + writefile = getattr(self, 'writefile', None) + if writefile is not None: + writefile.close() + + def read(self, offset, length): + """ + Read up to C{length} bytes from this file, starting at position + C{offset}. The offset may be a python long, since SFTP allows it + to be 64 bits. + + If the end of the file has been reached, this method may return an + empty string to signify EOF, or it may also return L{SFTP_EOF}. + + The default implementation checks for an attribute on C{self} named + C{readfile}, and if present, performs the read operation on the python + file-like object found there. (This is meant as a time saver for the + common case where you are wrapping a python file object.) + + @param offset: position in the file to start reading from. + @type offset: int or long + @param length: number of bytes to attempt to read. + @type length: int + @return: data read from the file, or an SFTP error code. + @rtype: str + """ + if not hasattr(self, 'readfile') or (self.readfile is None): + return SFTP_OP_UNSUPPORTED + try: + if self.__tell is None: + self.__tell = self.readfile.tell() + if offset != self.__tell: + self.readfile.seek(offset) + self.__tell = offset + data = self.readfile.read(length) + except IOError, e: + self.__tell = None + return SFTPServer.convert_errno(e.errno) + self.__tell += len(data) + return data + + def write(self, offset, data): + """ + Write C{data} into this file at position C{offset}. Extending the + file past its original end is expected. Unlike python's normal + C{write()} methods, this method cannot do a partial write: it must + write all of C{data} or else return an error. + + The default implementation checks for an attribute on C{self} named + C{writefile}, and if present, performs the write operation on the + python file-like object found there. The attribute is named + differently from C{readfile} to make it easy to implement read-only + (or write-only) files, but if both attributes are present, they should + refer to the same file. + + @param offset: position in the file to start reading from. + @type offset: int or long + @param data: data to write into the file. + @type data: str + @return: an SFTP error code like L{SFTP_OK}. + """ + if not hasattr(self, 'writefile') or (self.writefile is None): + return SFTP_OP_UNSUPPORTED + try: + if self.__tell is None: + self.__tell = self.writefile.tell() + if offset != self.__tell: + self.writefile.seek(offset) + self.__tell = offset + self.writefile.write(data) + self.writefile.flush() + except IOError, e: + self.__tell = None + return SFTPServer.convert_errno(e.errno) + self.__tell += len(data) + return SFTP_OK + + def stat(self): + """ + Return an L{SFTPAttributes} object referring to this open file, or an + error code. This is equivalent to L{SFTPServerInterface.stat}, except + it's called on an open file instead of a path. + + @return: an attributes object for the given file, or an SFTP error + code (like L{SFTP_PERMISSION_DENIED}). + @rtype: L{SFTPAttributes} I{or error code} + """ + return SFTP_OP_UNSUPPORTED + + def chattr(self, attr): + """ + Change the attributes of this file. The C{attr} object will contain + only those fields provided by the client in its request, so you should + check for the presence of fields before using them. + + @param attr: the attributes to change on this file. + @type attr: L{SFTPAttributes} + @return: an error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + + ### internals... + + + def _set_files(self, files): + """ + Used by the SFTP server code to cache a directory listing. (In + the SFTP protocol, listing a directory is a multi-stage process + requiring a temporary handle.) + """ + self.__files = files + + def _get_next_files(self): + """ + Used by the SFTP server code to retreive a cached directory + listing. + """ + fnlist = self.__files[:16] + self.__files = self.__files[16:] + return fnlist + + def _get_name(self): + return self.__name + + def _set_name(self, name): + self.__name = name + + +from paramiko.sftp_server import SFTPServer diff --git a/paramiko/sftp_server.py b/paramiko/sftp_server.py new file mode 100644 index 0000000..5905843 --- /dev/null +++ b/paramiko/sftp_server.py @@ -0,0 +1,420 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Server-mode SFTP support. +""" + +import os +import errno + +from Crypto.Hash import MD5, SHA +from paramiko.common import * +from paramiko.server import SubsystemHandler +from paramiko.sftp import * +from paramiko.sftp_si import * +from paramiko.sftp_attr import * + + +# known hash algorithms for the "check-file" extension +_hash_class = { + 'sha1': SHA, + 'md5': MD5, +} + + +class SFTPServer (BaseSFTP, SubsystemHandler): + """ + Server-side SFTP subsystem support. Since this is a L{SubsystemHandler}, + it can be (and is meant to be) set as the handler for C{"sftp"} requests. + Use L{Transport.set_subsystem_handler} to activate this class. + """ + + def __init__(self, channel, name, server, sftp_si=SFTPServerInterface, *largs, **kwargs): + """ + The constructor for SFTPServer is meant to be called from within the + L{Transport} as a subsystem handler. C{server} and any additional + parameters or keyword parameters are passed from the original call to + L{Transport.set_subsystem_handler}. + + @param channel: channel passed from the L{Transport}. + @type channel: L{Channel} + @param name: name of the requested subsystem. + @type name: str + @param server: the server object associated with this channel and + subsystem + @type server: L{ServerInterface} + @param sftp_si: a subclass of L{SFTPServerInterface} to use for handling + individual requests. + @type sftp_si: class + """ + BaseSFTP.__init__(self) + SubsystemHandler.__init__(self, channel, name, server) + transport = channel.get_transport() + self.logger = util.get_logger(transport.get_log_channel() + '.' + + channel.get_name() + '.sftp') + self.ultra_debug = transport.get_hexdump() + self.next_handle = 1 + # map of handle-string to SFTPHandle for files & folders: + self.file_table = { } + self.folder_table = { } + self.server = sftp_si(server, *largs, **kwargs) + + def start_subsystem(self, name, transport, channel): + self.sock = channel + self._log(DEBUG, 'Started sftp server on channel %s' % repr(channel)) + self._send_server_version() + self.server.session_started() + while True: + try: + t, data = self._read_packet() + except EOFError: + self._log(DEBUG, 'EOF -- end of session') + return + except Exception, e: + self._log(DEBUG, 'Exception on channel: ' + str(e)) + self._log(DEBUG, util.tb_strings()) + return + msg = Message(data) + request_number = msg.get_int() + self._process(t, request_number, msg) + + def finish_subsystem(self): + self.server.session_ended() + # close any file handles that were left open (so we can return them to the OS quickly) + for f in self.file_table.itervalues(): + f.close() + for f in self.folder_table.itervalues(): + f.close() + self.file_table = {} + self.folder_table = {} + + def convert_errno(e): + """ + Convert an errno value (as from an C{OSError} or C{IOError}) into a + standard SFTP result code. This is a convenience function for trapping + exceptions in server code and returning an appropriate result. + + @param e: an errno code, as from C{OSError.errno}. + @type e: int + @return: an SFTP error code like L{SFTP_NO_SUCH_FILE}. + @rtype: int + """ + if e == errno.EACCES: + # permission denied + return SFTP_PERMISSION_DENIED + elif e == errno.ENOENT: + # no such file + return SFTP_NO_SUCH_FILE + else: + return SFTP_FAILURE + convert_errno = staticmethod(convert_errno) + + def set_file_attr(filename, attr): + """ + Change a file's attributes on the local filesystem. The contents of + C{attr} are used to change the permissions, owner, group ownership, + and/or modification & access time of the file, depending on which + attributes are present in C{attr}. + + This is meant to be a handy helper function for translating SFTP file + requests into local file operations. + + @param filename: name of the file to alter (should usually be an + absolute path). + @type filename: str + @param attr: attributes to change. + @type attr: L{SFTPAttributes} + """ + if attr._flags & attr.FLAG_PERMISSIONS: + os.chmod(filename, attr.st_mode) + if attr._flags & attr.FLAG_UIDGID: + os.chown(filename, attr.st_uid, attr.st_gid) + if attr._flags & attr.FLAG_AMTIME: + os.utime(filename, (attr.st_atime, attr.st_mtime)) + set_file_attr = staticmethod(set_file_attr) + + + ### internals... + + + def _response(self, request_number, t, *arg): + msg = Message() + msg.add_int(request_number) + for item in arg: + if type(item) is int: + msg.add_int(item) + elif type(item) is long: + msg.add_int64(item) + elif type(item) is str: + msg.add_string(item) + elif type(item) is SFTPAttributes: + item._pack(msg) + else: + raise Exception('unknown type for ' + repr(item) + ' type ' + repr(type(item))) + self._send_packet(t, str(msg)) + + def _send_handle_response(self, request_number, handle, folder=False): + if not issubclass(type(handle), SFTPHandle): + # must be error code + self._send_status(request_number, handle) + return + handle._set_name('hx%d' % self.next_handle) + self.next_handle += 1 + if folder: + self.folder_table[handle._get_name()] = handle + else: + self.file_table[handle._get_name()] = handle + self._response(request_number, CMD_HANDLE, handle._get_name()) + + def _send_status(self, request_number, code, desc=None): + if desc is None: + desc = SFTP_DESC[code] + self._response(request_number, CMD_STATUS, code, desc) + + def _open_folder(self, request_number, path): + resp = self.server.list_folder(path) + if issubclass(type(resp), list): + # got an actual list of filenames in the folder + folder = SFTPHandle() + folder._set_files(resp) + self._send_handle_response(request_number, folder, True) + return + # must be an error code + self._send_status(request_number, resp) + + def _read_folder(self, request_number, folder): + flist = folder._get_next_files() + if len(flist) == 0: + self._send_status(request_number, SFTP_EOF) + return + msg = Message() + msg.add_int(request_number) + msg.add_int(len(flist)) + for attr in flist: + msg.add_string(attr.filename) + msg.add_string(str(attr)) + attr._pack(msg) + self._send_packet(CMD_NAME, str(msg)) + + def _check_file(self, request_number, msg): + # this extension actually comes from v6 protocol, but since it's an + # extension, i feel like we can reasonably support it backported. + # it's very useful for verifying uploaded files or checking for + # rsync-like differences between local and remote files. + handle = msg.get_string() + alg_list = msg.get_list() + start = msg.get_int64() + length = msg.get_int64() + block_size = msg.get_int() + if not self.file_table.has_key(handle): + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + f = self.file_table[handle] + for x in alg_list: + if x in _hash_class: + algname = x + alg = _hash_class[x] + break + else: + self._send_status(request_number, SFTP_FAILURE, 'No supported hash types found') + return + if length == 0: + st = f.stat() + if not issubclass(type(st), SFTPAttributes): + self._send_status(request_number, st, 'Unable to stat file') + return + length = st.st_size - start + if block_size == 0: + block_size = length + if block_size < 256: + self._send_status(request_number, SFTP_FAILURE, 'Block size too small') + return + + sum = '' + offset = start + while offset < start + length: + blocklen = min(block_size, start + length - offset) + # don't try to read more than about 64KB at a time + chunklen = min(blocklen, 65536) + count = 0 + hash = alg.new() + while count < blocklen: + data = f.read(offset, chunklen) + if not type(data) is str: + self._send_status(request_number, data, 'Unable to hash file') + return + hash.update(data) + count += len(data) + offset += count + sum += hash.digest() + + msg = Message() + msg.add_int(request_number) + msg.add_string('check-file') + msg.add_string(algname) + msg.add_bytes(sum) + self._send_packet(CMD_EXTENDED_REPLY, str(msg)) + + def _convert_pflags(self, pflags): + "convert SFTP-style open() flags to python's os.open() flags" + if (pflags & SFTP_FLAG_READ) and (pflags & SFTP_FLAG_WRITE): + flags = os.O_RDWR + elif pflags & SFTP_FLAG_WRITE: + flags = os.O_WRONLY + else: + flags = os.O_RDONLY + if pflags & SFTP_FLAG_APPEND: + flags |= os.O_APPEND + if pflags & SFTP_FLAG_CREATE: + flags |= os.O_CREAT + if pflags & SFTP_FLAG_TRUNC: + flags |= os.O_TRUNC + if pflags & SFTP_FLAG_EXCL: + flags |= os.O_EXCL + return flags + + def _process(self, t, request_number, msg): + self._log(DEBUG, 'Request: %s' % CMD_NAMES[t]) + if t == CMD_OPEN: + path = msg.get_string() + flags = self._convert_pflags(msg.get_int()) + attr = SFTPAttributes._from_msg(msg) + self._send_handle_response(request_number, self.server.open(path, flags, attr)) + elif t == CMD_CLOSE: + handle = msg.get_string() + if self.folder_table.has_key(handle): + del self.folder_table[handle] + self._send_status(request_number, SFTP_OK) + return + if self.file_table.has_key(handle): + self.file_table[handle].close() + del self.file_table[handle] + self._send_status(request_number, SFTP_OK) + return + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + elif t == CMD_READ: + handle = msg.get_string() + offset = msg.get_int64() + length = msg.get_int() + if not self.file_table.has_key(handle): + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + data = self.file_table[handle].read(offset, length) + if type(data) is str: + if len(data) == 0: + self._send_status(request_number, SFTP_EOF) + else: + self._response(request_number, CMD_DATA, data) + else: + self._send_status(request_number, data) + elif t == CMD_WRITE: + handle = msg.get_string() + offset = msg.get_int64() + data = msg.get_string() + if not self.file_table.has_key(handle): + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + self._send_status(request_number, self.file_table[handle].write(offset, data)) + elif t == CMD_REMOVE: + path = msg.get_string() + self._send_status(request_number, self.server.remove(path)) + elif t == CMD_RENAME: + oldpath = msg.get_string() + newpath = msg.get_string() + self._send_status(request_number, self.server.rename(oldpath, newpath)) + elif t == CMD_MKDIR: + path = msg.get_string() + attr = SFTPAttributes._from_msg(msg) + self._send_status(request_number, self.server.mkdir(path, attr)) + elif t == CMD_RMDIR: + path = msg.get_string() + self._send_status(request_number, self.server.rmdir(path)) + elif t == CMD_OPENDIR: + path = msg.get_string() + self._open_folder(request_number, path) + return + elif t == CMD_READDIR: + handle = msg.get_string() + if not self.folder_table.has_key(handle): + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + folder = self.folder_table[handle] + self._read_folder(request_number, folder) + elif t == CMD_STAT: + path = msg.get_string() + resp = self.server.stat(path) + if issubclass(type(resp), SFTPAttributes): + self._response(request_number, CMD_ATTRS, resp) + else: + self._send_status(request_number, resp) + elif t == CMD_LSTAT: + path = msg.get_string() + resp = self.server.lstat(path) + if issubclass(type(resp), SFTPAttributes): + self._response(request_number, CMD_ATTRS, resp) + else: + self._send_status(request_number, resp) + elif t == CMD_FSTAT: + handle = msg.get_string() + if not self.file_table.has_key(handle): + self._send_status(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + resp = self.file_table[handle].stat() + if issubclass(type(resp), SFTPAttributes): + self._response(request_number, CMD_ATTRS, resp) + else: + self._send_status(request_number, resp) + elif t == CMD_SETSTAT: + path = msg.get_string() + attr = SFTPAttributes._from_msg(msg) + self._send_status(request_number, self.server.chattr(path, attr)) + elif t == CMD_FSETSTAT: + handle = msg.get_string() + attr = SFTPAttributes._from_msg(msg) + if not self.file_table.has_key(handle): + self._response(request_number, SFTP_BAD_MESSAGE, 'Invalid handle') + return + self._send_status(request_number, self.file_table[handle].chattr(attr)) + elif t == CMD_READLINK: + path = msg.get_string() + resp = self.server.readlink(path) + if type(resp) is str: + self._response(request_number, CMD_NAME, 1, resp, '', SFTPAttributes()) + else: + self._send_status(request_number, resp) + elif t == CMD_SYMLINK: + # the sftp 2 draft is incorrect here! path always follows target_path + target_path = msg.get_string() + path = msg.get_string() + self._send_status(request_number, self.server.symlink(target_path, path)) + elif t == CMD_REALPATH: + path = msg.get_string() + rpath = self.server.canonicalize(path) + self._response(request_number, CMD_NAME, 1, rpath, '', SFTPAttributes()) + elif t == CMD_EXTENDED: + tag = msg.get_string() + if tag == 'check-file': + self._check_file(request_number, msg) + else: + send._send_status(request_number, SFTP_OP_UNSUPPORTED) + else: + self._send_status(request_number, SFTP_OP_UNSUPPORTED) + + +from paramiko.sftp_handle import SFTPHandle diff --git a/paramiko/sftp_si.py b/paramiko/sftp_si.py new file mode 100644 index 0000000..16005d4 --- /dev/null +++ b/paramiko/sftp_si.py @@ -0,0 +1,303 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{SFTPServerInterface} is an interface to override for SFTP server support. +""" + +import os + +from paramiko.common import * +from paramiko.sftp import * + + +class SFTPServerInterface (object): + """ + This class defines an interface for controlling the behavior of paramiko + when using the L{SFTPServer} subsystem to provide an SFTP server. + + Methods on this class are called from the SFTP session's thread, so you can + block as long as necessary without affecting other sessions (even other + SFTP sessions). However, raising an exception will usually cause the SFTP + session to abruptly end, so you will usually want to catch exceptions and + return an appropriate error code. + """ + + def __init__ (self, server, *largs, **kwargs): + """ + Create a new SFTPServerInterface object. This method does nothing by + default and is meant to be overridden by subclasses. + + @param server: the server object associated with this channel and + SFTP subsystem + @type server: L{ServerInterface} + """ + super(SFTPServerInterface, self).__init__(*largs, **kwargs) + + def session_started(self): + """ + The SFTP server session has just started. This method is meant to be + overridden to perform any necessary setup before handling callbacks + from SFTP operations. + """ + pass + + def session_ended(self): + """ + The SFTP server session has just ended, either cleanly or via an + exception. This method is meant to be overridden to perform any + necessary cleanup before this C{SFTPServerInterface} object is + destroyed. + """ + pass + + def open(self, path, flags, attr): + """ + Open a file on the server and create a handle for future operations + on that file. On success, a new object subclassed from L{SFTPHandle} + should be returned. This handle will be used for future operations + on the file (read, write, etc). On failure, an error code such as + L{SFTP_PERMISSION_DENIED} should be returned. + + C{flags} contains the requested mode for opening (read-only, + write-append, etc) as a bitset of flags from the C{os} module: + - C{os.O_RDONLY} + - C{os.O_WRONLY} + - C{os.O_RDWR} + - C{os.O_APPEND} + - C{os.O_CREAT} + - C{os.O_TRUNC} + - C{os.O_EXCL} + (One of C{os.O_RDONLY}, C{os.O_WRONLY}, or C{os.O_RDWR} will always + be set.) + + The C{attr} object contains requested attributes of the file if it + has to be created. Some or all attribute fields may be missing if + the client didn't specify them. + + @note: The SFTP protocol defines all files to be in "binary" mode. + There is no equivalent to python's "text" mode. + + @param path: the requested path (relative or absolute) of the file + to be opened. + @type path: str + @param flags: flags or'd together from the C{os} module indicating the + requested mode for opening the file. + @type flags: int + @param attr: requested attributes of the file if it is newly created. + @type attr: L{SFTPAttributes} + @return: a new L{SFTPHandle} I{or error code}. + @rtype L{SFTPHandle} + """ + return SFTP_OP_UNSUPPORTED + + def list_folder(self, path): + """ + Return a list of files within a given folder. The C{path} will use + posix notation (C{"/"} separates folder names) and may be an absolute + or relative path. + + The list of files is expected to be a list of L{SFTPAttributes} + objects, which are similar in structure to the objects returned by + C{os.stat}. In addition, each object should have its C{filename} + field filled in, since this is important to a directory listing and + not normally present in C{os.stat} results. The method + L{SFTPAttributes.from_stat} will usually do what you want. + + In case of an error, you should return one of the C{SFTP_*} error + codes, such as L{SFTP_PERMISSION_DENIED}. + + @param path: the requested path (relative or absolute) to be listed. + @type path: str + @return: a list of the files in the given folder, using + L{SFTPAttributes} objects. + @rtype: list of L{SFTPAttributes} I{or error code} + + @note: You should normalize the given C{path} first (see the + C{os.path} module) and check appropriate permissions before returning + the list of files. Be careful of malicious clients attempting to use + relative paths to escape restricted folders, if you're doing a direct + translation from the SFTP server path to your local filesystem. + """ + return SFTP_OP_UNSUPPORTED + + def stat(self, path): + """ + Return an L{SFTPAttributes} object for a path on the server, or an + error code. If your server supports symbolic links (also known as + "aliases"), you should follow them. (L{lstat} is the corresponding + call that doesn't follow symlinks/aliases.) + + @param path: the requested path (relative or absolute) to fetch + file statistics for. + @type path: str + @return: an attributes object for the given file, or an SFTP error + code (like L{SFTP_PERMISSION_DENIED}). + @rtype: L{SFTPAttributes} I{or error code} + """ + return SFTP_OP_UNSUPPORTED + + def lstat(self, path): + """ + Return an L{SFTPAttributes} object for a path on the server, or an + error code. If your server supports symbolic links (also known as + "aliases"), you should I{not} follow them -- instead, you should + return data on the symlink or alias itself. (L{stat} is the + corresponding call that follows symlinks/aliases.) + + @param path: the requested path (relative or absolute) to fetch + file statistics for. + @type path: str + @return: an attributes object for the given file, or an SFTP error + code (like L{SFTP_PERMISSION_DENIED}). + @rtype: L{SFTPAttributes} I{or error code} + """ + return SFTP_OP_UNSUPPORTED + + def remove(self, path): + """ + Delete a file, if possible. + + @param path: the requested path (relative or absolute) of the file + to delete. + @type path: str + @return: an SFTP error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + def rename(self, oldpath, newpath): + """ + Rename (or move) a file. The SFTP specification implies that this + method can be used to move an existing file into a different folder, + and since there's no other (easy) way to move files via SFTP, it's + probably a good idea to implement "move" in this method too, even for + files that cross disk partition boundaries, if at all possible. + + @note: You should return an error if a file with the same name as + C{newpath} already exists. (The rename operation should be + non-desctructive.) + + @param oldpath: the requested path (relative or absolute) of the + existing file. + @type oldpath: str + @param newpath: the requested new path of the file. + @type newpath: str + @return: an SFTP error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + def mkdir(self, path, attr): + """ + Create a new directory with the given attributes. The C{attr} + object may be considered a "hint" and ignored. + + The C{attr} object will contain only those fields provided by the + client in its request, so you should use C{hasattr} to check for + the presense of fields before using them. In some cases, the C{attr} + object may be completely empty. + + @param path: requested path (relative or absolute) of the new + folder. + @type path: str + @param attr: requested attributes of the new folder. + @type attr: L{SFTPAttributes} + @return: an SFTP error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + def rmdir(self, path): + """ + Remove a directory if it exists. The C{path} should refer to an + existing, empty folder -- otherwise this method should return an + error. + + @param path: requested path (relative or absolute) of the folder + to remove. + @type path: str + @return: an SFTP error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + def chattr(self, path, attr): + """ + Change the attributes of a file. The C{attr} object will contain + only those fields provided by the client in its request, so you + should check for the presence of fields before using them. + + @param path: requested path (relative or absolute) of the file to + change. + @type path: str + @param attr: requested attributes to change on the file. + @type attr: L{SFTPAttributes} + @return: an error code like L{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED + + def canonicalize(self, path): + """ + Return the canonical form of a path on the server. For example, + if the server's home folder is C{/home/foo}, the path + C{"../betty"} would be canonicalized to C{"/home/betty"}. Note + the obvious security issues: if you're serving files only from a + specific folder, you probably don't want this method to reveal path + names outside that folder. + + You may find the python methods in C{os.path} useful, especially + C{os.path.normpath} and C{os.path.realpath}. + + The default implementation returns C{os.path.normpath('/' + path)}. + """ + if os.path.isabs(path): + return os.path.normpath(path) + else: + return os.path.normpath('/' + path) + + def readlink(self, path): + """ + Return the target of a symbolic link (or shortcut) on the server. + If the specified path doesn't refer to a symbolic link, an error + should be returned. + + @param path: path (relative or absolute) of the symbolic link. + @type path: str + @return: the target path of the symbolic link, or an error code like + L{SFTP_NO_SUCH_FILE}. + @rtype: str I{or error code} + """ + return SFTP_OP_UNSUPPORTED + + def symlink(self, target_path, path): + """ + Create a symbolic link on the server, as new pathname C{path}, + with C{target_path} as the target of the link. + + @param target_path: path (relative or absolute) of the target for + this new symbolic link. + @type target_path: str + @param path: path (relative or absolute) of the symbolic link to + create. + @type path: str + @return: an error code like C{SFTP_OK}. + @rtype: int + """ + return SFTP_OP_UNSUPPORTED diff --git a/paramiko/ssh_exception.py b/paramiko/ssh_exception.py new file mode 100644 index 0000000..900d4a0 --- /dev/null +++ b/paramiko/ssh_exception.py @@ -0,0 +1,69 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Exceptions defined by paramiko. +""" + + +class SSHException (Exception): + """ + Exception raised by failures in SSH2 protocol negotiation or logic errors. + """ + pass + + +class PasswordRequiredException (SSHException): + """ + Exception raised when a password is needed to unlock a private key file. + """ + pass + + +class BadAuthenticationType (SSHException): + """ + Exception raised when an authentication type (like password) is used, but + the server isn't allowing that type. (It may only allow public-key, for + example.) + + @ivar allowed_types: list of allowed authentication types provided by the + server (possible values are: C{"none"}, C{"password"}, and + C{"publickey"}). + @type allowed_types: list + + @since: 1.1 + """ + allowed_types = [] + + def __init__(self, explanation, types): + SSHException.__init__(self, explanation) + self.allowed_types = types + + def __str__(self): + return SSHException.__str__(self) + ' (allowed_types=%r)' % self.allowed_types + + +class PartialAuthentication (SSHException): + """ + An internal exception thrown in the case of partial authentication. + """ + allowed_types = [] + + def __init__(self, types): + SSHException.__init__(self, 'partial authentication') + self.allowed_types = types diff --git a/paramiko/transport.py b/paramiko/transport.py new file mode 100644 index 0000000..8714a96 --- /dev/null +++ b/paramiko/transport.py @@ -0,0 +1,1824 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +L{Transport} handles the core SSH2 protocol. +""" + +import os +import socket +import string +import struct +import sys +import threading +import time +import weakref + +from paramiko import util +from paramiko.common import * +from paramiko.compress import ZlibCompressor, ZlibDecompressor +from paramiko.ssh_exception import SSHException, BadAuthenticationType +from paramiko.message import Message +from paramiko.channel import Channel +from paramiko.sftp_client import SFTPClient +from paramiko.packet import Packetizer, NeedRekeyException +from paramiko.rsakey import RSAKey +from paramiko.dsskey import DSSKey +from paramiko.kex_group1 import KexGroup1 +from paramiko.kex_gex import KexGex +from paramiko.primes import ModulusPack +from paramiko.auth_handler import AuthHandler + +# these come from PyCrypt +# http://www.amk.ca/python/writing/pycrypt/ +# i believe this on the standards track. +# PyCrypt compiled for Win32 can be downloaded from the HashTar homepage: +# http://nitace.bsd.uchicago.edu:8080/hashtar +from Crypto.Cipher import Blowfish, AES, DES3 +from Crypto.Hash import SHA, MD5, HMAC + + +# for thread cleanup +_active_threads = [] +def _join_lingering_threads(): + for thr in _active_threads: + thr.stop_thread() +import atexit +atexit.register(_join_lingering_threads) + + +class SecurityOptions (object): + """ + Simple object containing the security preferences of an ssh transport. + These are tuples of acceptable ciphers, digests, key types, and key + exchange algorithms, listed in order of preference. + + Changing the contents and/or order of these fields affects the underlying + L{Transport} (but only if you change them before starting the session). + If you try to add an algorithm that paramiko doesn't recognize, + C{ValueError} will be raised. If you try to assign something besides a + tuple to one of the fields, C{TypeError} will be raised. + + @since: ivysaur + """ + __slots__ = [ 'ciphers', 'digests', 'key_types', 'kex', 'compression', '_transport' ] + + def __init__(self, transport): + self._transport = transport + + def __repr__(self): + """ + Returns a string representation of this object, for debugging. + + @rtype: str + """ + return '<paramiko.SecurityOptions for %s>' % repr(self._transport) + + def _get_ciphers(self): + return self._transport._preferred_ciphers + + def _get_digests(self): + return self._transport._preferred_macs + + def _get_key_types(self): + return self._transport._preferred_keys + + def _get_kex(self): + return self._transport._preferred_kex + + def _get_compression(self): + return self._transport._preferred_compression + + def _set(self, name, orig, x): + if type(x) is list: + x = tuple(x) + if type(x) is not tuple: + raise TypeError('expected tuple or list') + possible = getattr(self._transport, orig).keys() + if len(filter(lambda n: n not in possible, x)) > 0: + raise ValueError('unknown cipher') + setattr(self._transport, name, x) + + def _set_ciphers(self, x): + self._set('_preferred_ciphers', '_cipher_info', x) + + def _set_digests(self, x): + self._set('_preferred_macs', '_mac_info', x) + + def _set_key_types(self, x): + self._set('_preferred_keys', '_key_info', x) + + def _set_kex(self, x): + self._set('_preferred_kex', '_kex_info', x) + + def _set_compression(self, x): + self._set('_preferred_compression', '_compression_info', x) + + ciphers = property(_get_ciphers, _set_ciphers, None, + "Symmetric encryption ciphers") + digests = property(_get_digests, _set_digests, None, + "Digest (one-way hash) algorithms") + key_types = property(_get_key_types, _set_key_types, None, + "Public-key algorithms") + kex = property(_get_kex, _set_kex, None, "Key exchange algorithms") + compression = property(_get_compression, _set_compression, None, + "Compression algorithms") + + +class Transport (threading.Thread): + """ + An SSH Transport attaches to a stream (usually a socket), negotiates an + encrypted session, authenticates, and then creates stream tunnels, called + L{Channel}s, across the session. Multiple channels can be multiplexed + across a single session (and often are, in the case of port forwardings). + """ + + _PROTO_ID = '2.0' + _CLIENT_ID = 'paramiko_1.5.2' + + _preferred_ciphers = ( 'aes128-cbc', 'blowfish-cbc', 'aes256-cbc', '3des-cbc' ) + _preferred_macs = ( 'hmac-sha1', 'hmac-md5', 'hmac-sha1-96', 'hmac-md5-96' ) + _preferred_keys = ( 'ssh-rsa', 'ssh-dss' ) + _preferred_kex = ( 'diffie-hellman-group1-sha1', 'diffie-hellman-group-exchange-sha1' ) + _preferred_compression = ( 'none', ) + + _cipher_info = { + 'blowfish-cbc': { 'class': Blowfish, 'mode': Blowfish.MODE_CBC, 'block-size': 8, 'key-size': 16 }, + 'aes128-cbc': { 'class': AES, 'mode': AES.MODE_CBC, 'block-size': 16, 'key-size': 16 }, + 'aes256-cbc': { 'class': AES, 'mode': AES.MODE_CBC, 'block-size': 16, 'key-size': 32 }, + '3des-cbc': { 'class': DES3, 'mode': DES3.MODE_CBC, 'block-size': 8, 'key-size': 24 }, + } + + _mac_info = { + 'hmac-sha1': { 'class': SHA, 'size': 20 }, + 'hmac-sha1-96': { 'class': SHA, 'size': 12 }, + 'hmac-md5': { 'class': MD5, 'size': 16 }, + 'hmac-md5-96': { 'class': MD5, 'size': 12 }, + } + + _key_info = { + 'ssh-rsa': RSAKey, + 'ssh-dss': DSSKey, + } + + _kex_info = { + 'diffie-hellman-group1-sha1': KexGroup1, + 'diffie-hellman-group-exchange-sha1': KexGex, + } + + _compression_info = { + # zlib@openssh.com is just zlib, but only turned on after a successful + # authentication. openssh servers may only offer this type because + # they've had troubles with security holes in zlib in the past. + 'zlib@openssh.com': ( ZlibCompressor, ZlibDecompressor ), + 'zlib': ( ZlibCompressor, ZlibDecompressor ), + 'none': ( None, None ), + } + + + _modulus_pack = None + + def __init__(self, sock): + """ + Create a new SSH session over an existing socket, or socket-like + object. This only creates the Transport object; it doesn't begin the + SSH session yet. Use L{connect} or L{start_client} to begin a client + session, or L{start_server} to begin a server session. + + If the object is not actually a socket, it must have the following + methods: + - C{send(str)}: Writes from 1 to C{len(str)} bytes, and + returns an int representing the number of bytes written. Returns + 0 or raises C{EOFError} if the stream has been closed. + - C{recv(int)}: Reads from 1 to C{int} bytes and returns them as a + string. Returns 0 or raises C{EOFError} if the stream has been + closed. + - C{close()}: Closes the socket. + - C{settimeout(n)}: Sets a (float) timeout on I/O operations. + + For ease of use, you may also pass in an address (as a tuple) or a host + string as the C{sock} argument. (A host string is a hostname with an + optional port (separated by C{":"}) which will be converted into a + tuple of C{(hostname, port)}.) A socket will be connected to this + address and used for communication. Exceptions from the C{socket} call + may be thrown in this case. + + @param sock: a socket or socket-like object to create the session over. + @type sock: socket + """ + if type(sock) is str: + # convert "host:port" into (host, port) + hl = sock.split(':', 1) + if len(hl) == 1: + sock = (hl[0], 22) + else: + sock = (hl[0], int(hl[1])) + if type(sock) is tuple: + # connect to the given (host, port) + hostname, port = sock + sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + sock.connect((hostname, port)) + # okay, normal socket-ish flow here... + threading.Thread.__init__(self) + self.randpool = randpool + self.sock = sock + # Python < 2.3 doesn't have the settimeout method - RogerB + try: + # we set the timeout so we can check self.active periodically to + # see if we should bail. socket.timeout exception is never + # propagated. + self.sock.settimeout(0.1) + except AttributeError: + pass + # negotiated crypto parameters + self.packetizer = Packetizer(sock) + self.local_version = 'SSH-' + self._PROTO_ID + '-' + self._CLIENT_ID + self.remote_version = '' + self.local_cipher = self.remote_cipher = '' + self.local_kex_init = self.remote_kex_init = None + self.session_id = None + # /negotiated crypto parameters + self.expected_packet = 0 + self.active = False + self.initial_kex_done = False + self.in_kex = False + self.lock = threading.Lock() # synchronization (always higher level than write_lock) + self.channels = weakref.WeakValueDictionary() # (id -> Channel) + self.channel_events = { } # (id -> Event) + self.channels_seen = { } # (id -> True) + self.channel_counter = 1 + self.window_size = 65536 + self.max_packet_size = 34816 + self.saved_exception = None + self.clear_to_send = threading.Event() + self.clear_to_send_lock = threading.Lock() + self.log_name = 'paramiko.transport' + self.logger = util.get_logger(self.log_name) + self.packetizer.set_log(self.logger) + self.auth_handler = None + self.authenticated = False + # user-defined event callbacks: + self.completion_event = None + # server mode: + self.server_mode = False + self.server_object = None + self.server_key_dict = { } + self.server_accepts = [ ] + self.server_accept_cv = threading.Condition(self.lock) + self.subsystem_table = { } + + def __del__(self): + self.close() + + def __repr__(self): + """ + Returns a string representation of this object, for debugging. + + @rtype: str + """ + out = '<paramiko.Transport at %s' % hex(long(id(self)) & 0xffffffffL) + if not self.active: + out += ' (unconnected)' + else: + if self.local_cipher != '': + out += ' (cipher %s, %d bits)' % (self.local_cipher, + self._cipher_info[self.local_cipher]['key-size'] * 8) + if self.is_authenticated(): + if len(self.channels) == 1: + out += ' (active; 1 open channel)' + else: + out += ' (active; %d open channels)' % len(self.channels) + elif self.initial_kex_done: + out += ' (connected; awaiting auth)' + else: + out += ' (connecting)' + out += '>' + return out + + def get_security_options(self): + """ + Return a L{SecurityOptions} object which can be used to tweak the + encryption algorithms this transport will permit, and the order of + preference for them. + + @return: an object that can be used to change the preferred algorithms + for encryption, digest (hash), public key, and key exchange. + @rtype: L{SecurityOptions} + + @since: ivysaur + """ + return SecurityOptions(self) + + def start_client(self, event=None): + """ + Negotiate a new SSH2 session as a client. This is the first step after + creating a new L{Transport}. A separate thread is created for protocol + negotiation. + + If an event is passed in, this method returns immediately. When + negotiation is done (successful or not), the given C{Event} will + be triggered. On failure, L{is_active} will return C{False}. + + (Since 1.4) If C{event} is C{None}, this method will not return until + negotation is done. On success, the method returns normally. + Otherwise an SSHException is raised. + + After a successful negotiation, you will usually want to authenticate, + calling L{auth_password <Transport.auth_password>} or + L{auth_publickey <Transport.auth_publickey>}. + + @note: L{connect} is a simpler method for connecting as a client. + + @note: After calling this method (or L{start_server} or L{connect}), + you should no longer directly read from or write to the original + socket object. + + @param event: an event to trigger when negotiation is complete + (optional) + @type event: threading.Event + + @raise SSHException: if negotiation fails (and no C{event} was passed + in) + """ + self.active = True + if event is not None: + # async, return immediately and let the app poll for completion + self.completion_event = event + self.start() + return + + # synchronous, wait for a result + self.completion_event = event = threading.Event() + self.start() + while True: + event.wait(0.1) + if not self.active: + e = self.get_exception() + if e is not None: + raise e + raise SSHException('Negotiation failed.') + if event.isSet(): + break + + def start_server(self, event=None, server=None): + """ + Negotiate a new SSH2 session as a server. This is the first step after + creating a new L{Transport} and setting up your server host key(s). A + separate thread is created for protocol negotiation. + + If an event is passed in, this method returns immediately. When + negotiation is done (successful or not), the given C{Event} will + be triggered. On failure, L{is_active} will return C{False}. + + (Since 1.4) If C{event} is C{None}, this method will not return until + negotation is done. On success, the method returns normally. + Otherwise an SSHException is raised. + + After a successful negotiation, the client will need to authenticate. + Override the methods + L{get_allowed_auths <ServerInterface.get_allowed_auths>}, + L{check_auth_none <ServerInterface.check_auth_none>}, + L{check_auth_password <ServerInterface.check_auth_password>}, and + L{check_auth_publickey <ServerInterface.check_auth_publickey>} in the + given C{server} object to control the authentication process. + + After a successful authentication, the client should request to open + a channel. Override + L{check_channel_request <ServerInterface.check_channel_request>} in the + given C{server} object to allow channels to be opened. + + @note: After calling this method (or L{start_client} or L{connect}), + you should no longer directly read from or write to the original + socket object. + + @param event: an event to trigger when negotiation is complete. + @type event: threading.Event + @param server: an object used to perform authentication and create + L{Channel}s. + @type server: L{server.ServerInterface} + + @raise SSHException: if negotiation fails (and no C{event} was passed + in) + """ + if server is None: + server = ServerInterface() + self.server_mode = True + self.server_object = server + self.active = True + if event is not None: + # async, return immediately and let the app poll for completion + self.completion_event = event + self.start() + return + + # synchronous, wait for a result + self.completion_event = event = threading.Event() + self.start() + while True: + event.wait(0.1) + if not self.active: + e = self.get_exception() + if e is not None: + raise e + raise SSHException('Negotiation failed.') + if event.isSet(): + break + + def add_server_key(self, key): + """ + Add a host key to the list of keys used for server mode. When behaving + as a server, the host key is used to sign certain packets during the + SSH2 negotiation, so that the client can trust that we are who we say + we are. Because this is used for signing, the key must contain private + key info, not just the public half. Only one key of each type (RSA or + DSS) is kept. + + @param key: the host key to add, usually an L{RSAKey <rsakey.RSAKey>} or + L{DSSKey <dsskey.DSSKey>}. + @type key: L{PKey <pkey.PKey>} + """ + self.server_key_dict[key.get_name()] = key + + def get_server_key(self): + """ + Return the active host key, in server mode. After negotiating with the + client, this method will return the negotiated host key. If only one + type of host key was set with L{add_server_key}, that's the only key + that will ever be returned. But in cases where you have set more than + one type of host key (for example, an RSA key and a DSS key), the key + type will be negotiated by the client, and this method will return the + key of the type agreed on. If the host key has not been negotiated + yet, C{None} is returned. In client mode, the behavior is undefined. + + @return: host key of the type negotiated by the client, or C{None}. + @rtype: L{PKey <pkey.PKey>} + """ + try: + return self.server_key_dict[self.host_key_type] + except KeyError: + return None + + def load_server_moduli(filename=None): + """ + I{(optional)} + Load a file of prime moduli for use in doing group-exchange key + negotiation in server mode. It's a rather obscure option and can be + safely ignored. + + In server mode, the remote client may request "group-exchange" key + negotiation, which asks the server to send a random prime number that + fits certain criteria. These primes are pretty difficult to compute, + so they can't be generated on demand. But many systems contain a file + of suitable primes (usually named something like C{/etc/ssh/moduli}). + If you call C{load_server_moduli} and it returns C{True}, then this + file of primes has been loaded and we will support "group-exchange" in + server mode. Otherwise server mode will just claim that it doesn't + support that method of key negotiation. + + @param filename: optional path to the moduli file, if you happen to + know that it's not in a standard location. + @type filename: str + @return: True if a moduli file was successfully loaded; False + otherwise. + @rtype: bool + + @since: doduo + + @note: This has no effect when used in client mode. + """ + Transport._modulus_pack = ModulusPack(randpool) + # places to look for the openssh "moduli" file + file_list = [ '/etc/ssh/moduli', '/usr/local/etc/moduli' ] + if filename is not None: + file_list.insert(0, filename) + for fn in file_list: + try: + Transport._modulus_pack.read_file(fn) + return True + except IOError: + pass + # none succeeded + Transport._modulus_pack = None + return False + load_server_moduli = staticmethod(load_server_moduli) + + def close(self): + """ + Close this session, and any open channels that are tied to it. + """ + self.active = False + # since this may be called from __del__, can't assume any attributes exist + try: + self.packetizer.close() + for chan in self.channels.values(): + chan._unlink() + except AttributeError: + pass + + def get_remote_server_key(self): + """ + Return the host key of the server (in client mode). + + @note: Previously this call returned a tuple of (key type, key string). + You can get the same effect by calling + L{PKey.get_name <pkey.PKey.get_name>} for the key type, and + C{str(key)} for the key string. + + @raise SSHException: if no session is currently active. + + @return: public key of the remote server. + @rtype: L{PKey <pkey.PKey>} + """ + if (not self.active) or (not self.initial_kex_done): + raise SSHException('No existing session') + return self.host_key + + def is_active(self): + """ + Return true if this session is active (open). + + @return: True if the session is still active (open); False if the + session is closed. + @rtype: bool + """ + return self.active + + def open_session(self): + """ + Request a new channel to the server, of type C{"session"}. This + is just an alias for C{open_channel('session')}. + + @return: a new L{Channel} on success, or C{None} if the request is + rejected or the session ends prematurely. + @rtype: L{Channel} + """ + return self.open_channel('session') + + def open_channel(self, kind, dest_addr=None, src_addr=None): + """ + Request a new channel to the server. L{Channel}s are socket-like + objects used for the actual transfer of data across the session. + You may only request a channel after negotiating encryption (using + L{connect} or L{start_client}) and authenticating. + + @param kind: the kind of channel requested (usually C{"session"}, + C{"forwarded-tcpip"} or C{"direct-tcpip"}). + @type kind: str + @param dest_addr: the destination address of this port forwarding, + if C{kind} is C{"forwarded-tcpip"} or C{"direct-tcpip"} (ignored + for other channel types). + @type dest_addr: (str, int) + @param src_addr: the source address of this port forwarding, if + C{kind} is C{"forwarded-tcpip"} or C{"direct-tcpip"}. + @type src_addr: (str, int) + @return: a new L{Channel} on success, or C{None} if the request is + rejected or the session ends prematurely. + @rtype: L{Channel} + """ + chan = None + if not self.active: + # don't bother trying to allocate a channel + return None + self.lock.acquire() + try: + chanid = self.channel_counter + while self.channels.has_key(chanid): + self.channel_counter = (self.channel_counter + 1) & 0xffffff + chanid = self.channel_counter + self.channel_counter = (self.channel_counter + 1) & 0xffffff + m = Message() + m.add_byte(chr(MSG_CHANNEL_OPEN)) + m.add_string(kind) + m.add_int(chanid) + m.add_int(self.window_size) + m.add_int(self.max_packet_size) + if (kind == 'forwarded-tcpip') or (kind == 'direct-tcpip'): + m.add_string(dest_addr[0]) + m.add_int(dest_addr[1]) + m.add_string(src_addr[0]) + m.add_int(src_addr[1]) + self.channels[chanid] = chan = Channel(chanid) + self.channel_events[chanid] = event = threading.Event() + self.channels_seen[chanid] = True + chan._set_transport(self) + chan._set_window(self.window_size, self.max_packet_size) + finally: + self.lock.release() + self._send_user_message(m) + while 1: + event.wait(0.1); + if not self.active: + return None + if event.isSet(): + break + try: + self.lock.acquire() + if not self.channels.has_key(chanid): + chan = None + finally: + self.lock.release() + return chan + + def open_sftp_client(self): + """ + Create an SFTP client channel from an open transport. On success, + an SFTP session will be opened with the remote host, and a new + SFTPClient object will be returned. + + @return: a new L{SFTPClient} object, referring to an sftp session + (channel) across this transport + @rtype: L{SFTPClient} + """ + return SFTPClient.from_transport(self) + + def send_ignore(self, bytes=None): + """ + Send a junk packet across the encrypted link. This is sometimes used + to add "noise" to a connection to confuse would-be attackers. It can + also be used as a keep-alive for long lived connections traversing + firewalls. + + @param bytes: the number of random bytes to send in the payload of the + ignored packet -- defaults to a random number from 10 to 41. + @type bytes: int + + @since: fearow + """ + m = Message() + m.add_byte(chr(MSG_IGNORE)) + randpool.stir() + if bytes is None: + bytes = (ord(randpool.get_bytes(1)) % 32) + 10 + m.add_bytes(randpool.get_bytes(bytes)) + self._send_user_message(m) + + def renegotiate_keys(self): + """ + Force this session to switch to new keys. Normally this is done + automatically after the session hits a certain number of packets or + bytes sent or received, but this method gives you the option of forcing + new keys whenever you want. Negotiating new keys causes a pause in + traffic both ways as the two sides swap keys and do computations. This + method returns when the session has switched to new keys, or the + session has died mid-negotiation. + + @return: True if the renegotiation was successful, and the link is + using new keys; False if the session dropped during renegotiation. + @rtype: bool + """ + self.completion_event = threading.Event() + self._send_kex_init() + while 1: + self.completion_event.wait(0.1); + if not self.active: + return False + if self.completion_event.isSet(): + break + return True + + def set_keepalive(self, interval): + """ + Turn on/off keepalive packets (default is off). If this is set, after + C{interval} seconds without sending any data over the connection, a + "keepalive" packet will be sent (and ignored by the remote host). This + can be useful to keep connections alive over a NAT, for example. + + @param interval: seconds to wait before sending a keepalive packet (or + 0 to disable keepalives). + @type interval: int + + @since: fearow + """ + self.packetizer.set_keepalive(interval, + lambda x=self: x.global_request('keepalive@lag.net', wait=False)) + + def global_request(self, kind, data=None, wait=True): + """ + Make a global request to the remote host. These are normally + extensions to the SSH2 protocol. + + @param kind: name of the request. + @type kind: str + @param data: an optional tuple containing additional data to attach + to the request. + @type data: tuple + @param wait: C{True} if this method should not return until a response + is received; C{False} otherwise. + @type wait: bool + @return: a L{Message} containing possible additional data if the + request was successful (or an empty L{Message} if C{wait} was + C{False}); C{None} if the request was denied. + @rtype: L{Message} + + @since: fearow + """ + if wait: + self.completion_event = threading.Event() + m = Message() + m.add_byte(chr(MSG_GLOBAL_REQUEST)) + m.add_string(kind) + m.add_boolean(wait) + if data is not None: + m.add(*data) + self._log(DEBUG, 'Sending global request "%s"' % kind) + self._send_user_message(m) + if not wait: + return None + while True: + self.completion_event.wait(0.1) + if not self.active: + return None + if self.completion_event.isSet(): + break + return self.global_response + + def accept(self, timeout=None): + """ + Return the next channel opened by the client over this transport, in + server mode. If no channel is opened before the given timeout, C{None} + is returned. + + @param timeout: seconds to wait for a channel, or C{None} to wait + forever + @type timeout: int + @return: a new Channel opened by the client + @rtype: L{Channel} + """ + self.lock.acquire() + try: + if len(self.server_accepts) > 0: + chan = self.server_accepts.pop(0) + else: + self.server_accept_cv.wait(timeout) + if len(self.server_accepts) > 0: + chan = self.server_accepts.pop(0) + else: + # timeout + chan = None + finally: + self.lock.release() + return chan + + def connect(self, hostkey=None, username='', password=None, pkey=None): + """ + Negotiate an SSH2 session, and optionally verify the server's host key + and authenticate using a password or private key. This is a shortcut + for L{start_client}, L{get_remote_server_key}, and + L{Transport.auth_password} or L{Transport.auth_publickey}. Use those + methods if you want more control. + + You can use this method immediately after creating a Transport to + negotiate encryption with a server. If it fails, an exception will be + thrown. On success, the method will return cleanly, and an encrypted + session exists. You may immediately call L{open_channel} or + L{open_session} to get a L{Channel} object, which is used for data + transfer. + + @note: If you fail to supply a password or private key, this method may + succeed, but a subsequent L{open_channel} or L{open_session} call may + fail because you haven't authenticated yet. + + @param hostkey: the host key expected from the server, or C{None} if + you don't want to do host key verification. + @type hostkey: L{PKey<pkey.PKey>} + @param username: the username to authenticate as. + @type username: str + @param password: a password to use for authentication, if you want to + use password authentication; otherwise C{None}. + @type password: str + @param pkey: a private key to use for authentication, if you want to + use private key authentication; otherwise C{None}. + @type pkey: L{PKey<pkey.PKey>} + + @raise SSHException: if the SSH2 negotiation fails, the host key + supplied by the server is incorrect, or authentication fails. + + @since: doduo + """ + if hostkey is not None: + self._preferred_keys = [ hostkey.get_name() ] + + self.start_client() + + # check host key if we were given one + if (hostkey is not None): + key = self.get_remote_server_key() + if (key.get_name() != hostkey.get_name()) or (str(key) != str(hostkey)): + self._log(DEBUG, 'Bad host key from server') + self._log(DEBUG, 'Expected: %s: %s' % (hostkey.get_name(), repr(str(hostkey)))) + self._log(DEBUG, 'Got : %s: %s' % (key.get_name(), repr(str(key)))) + raise SSHException('Bad host key from server') + self._log(DEBUG, 'Host key verified (%s)' % hostkey.get_name()) + + if (pkey is not None) or (password is not None): + if password is not None: + self._log(DEBUG, 'Attempting password auth...') + self.auth_password(username, password) + else: + self._log(DEBUG, 'Attempting public-key auth...') + self.auth_publickey(username, pkey) + + return + + def get_exception(self): + """ + Return any exception that happened during the last server request. + This can be used to fetch more specific error information after using + calls like L{start_client}. The exception (if any) is cleared after + this call. + + @return: an exception, or C{None} if there is no stored exception. + @rtype: Exception + + @since: 1.1 + """ + self.lock.acquire() + try: + e = self.saved_exception + self.saved_exception = None + return e + finally: + self.lock.release() + + def set_subsystem_handler(self, name, handler, *larg, **kwarg): + """ + Set the handler class for a subsystem in server mode. If a request + for this subsystem is made on an open ssh channel later, this handler + will be constructed and called -- see L{SubsystemHandler} for more + detailed documentation. + + Any extra parameters (including keyword arguments) are saved and + passed to the L{SubsystemHandler} constructor later. + + @param name: name of the subsystem. + @type name: str + @param handler: subclass of L{SubsystemHandler} that handles this + subsystem. + @type handler: class + """ + try: + self.lock.acquire() + self.subsystem_table[name] = (handler, larg, kwarg) + finally: + self.lock.release() + + def is_authenticated(self): + """ + Return true if this session is active and authenticated. + + @return: True if the session is still open and has been authenticated + successfully; False if authentication failed and/or the session is + closed. + @rtype: bool + """ + return self.active and (self.auth_handler is not None) and self.auth_handler.is_authenticated() + + def get_username(self): + """ + Return the username this connection is authenticated for. If the + session is not authenticated (or authentication failed), this method + returns C{None}. + + @return: username that was authenticated, or C{None}. + @rtype: string + + @since: fearow + """ + if not self.active or (self.auth_handler is None): + return None + return self.auth_handler.get_username() + + def auth_none(self, username): + """ + Try to authenticate to the server using no authentication at all. + This will almost always fail. It may be useful for determining the + list of authentication types supported by the server, by catching the + L{BadAuthenticationType} exception raised. + + @param username: the username to authenticate as + @type username: string + @return: list of auth types permissible for the next stage of + authentication (normally empty) + @rtype: list + + @raise BadAuthenticationType: if "none" authentication isn't allowed + by the server for this user + @raise SSHException: if the authentication failed due to a network + error + + @since: 1.5 + """ + if (not self.active) or (not self.initial_kex_done): + raise SSHException('No existing session') + my_event = threading.Event() + self.auth_handler = AuthHandler(self) + self.auth_handler.auth_none(username, my_event) + return self.auth_handler.wait_for_response(my_event) + + def auth_password(self, username, password, event=None, fallback=True): + """ + Authenticate to the server using a password. The username and password + are sent over an encrypted link. + + If an C{event} is passed in, this method will return immediately, and + the event will be triggered once authentication succeeds or fails. On + success, L{is_authenticated} will return C{True}. On failure, you may + use L{get_exception} to get more detailed error information. + + Since 1.1, if no event is passed, this method will block until the + authentication succeeds or fails. On failure, an exception is raised. + Otherwise, the method simply returns. + + Since 1.5, if no event is passed and C{fallback} is C{True} (the + default), if the server doesn't support plain password authentication + but does support so-called "keyboard-interactive" mode, an attempt + will be made to authenticate using this interactive mode. If it fails, + the normal exception will be thrown as if the attempt had never been + made. This is useful for some recent Gentoo and Debian distributions, + which turn off plain password authentication in a misguided belief + that interactive authentication is "more secure". (It's not.) + + If the server requires multi-step authentication (which is very rare), + this method will return a list of auth types permissible for the next + step. Otherwise, in the normal case, an empty list is returned. + + @param username: the username to authenticate as + @type username: string + @param password: the password to authenticate with + @type password: string + @param event: an event to trigger when the authentication attempt is + complete (whether it was successful or not) + @type event: threading.Event + @param fallback: C{True} if an attempt at an automated "interactive" + password auth should be made if the server doesn't support normal + password auth + @type fallback: bool + @return: list of auth types permissible for the next stage of + authentication (normally empty) + @rtype: list + + @raise BadAuthenticationType: if password authentication isn't + allowed by the server for this user (and no event was passed in) + @raise SSHException: if the authentication failed (and no event was + passed in) + """ + if (not self.active) or (not self.initial_kex_done): + # we should never try to send the password unless we're on a secure link + raise SSHException('No existing session') + if event is None: + my_event = threading.Event() + else: + my_event = event + self.auth_handler = AuthHandler(self) + self.auth_handler.auth_password(username, password, my_event) + if event is not None: + # caller wants to wait for event themselves + return [] + try: + return self.auth_handler.wait_for_response(my_event) + except BadAuthenticationType, x: + # if password auth isn't allowed, but keyboard-interactive *is*, try to fudge it + if not fallback or not 'keyboard-interactive' in x.allowed_types: + raise + try: + def handler(title, instructions, fields): + if len(fields) > 1: + raise SSHException('Fallback authentication failed.') + if len(fields) == 0: + # for some reason, at least on os x, a 2nd request will + # be made with zero fields requested. maybe it's just + # to try to fake out automated scripting of the exact + # type we're doing here. *shrug* :) + return [] + return [ password ] + return self.auth_interactive(username, handler) + except SSHException, ignored: + # attempt failed; just raise the original exception + raise x + + def auth_publickey(self, username, key, event=None): + """ + Authenticate to the server using a private key. The key is used to + sign data from the server, so it must include the private part. + + If an C{event} is passed in, this method will return immediately, and + the event will be triggered once authentication succeeds or fails. On + success, L{is_authenticated} will return C{True}. On failure, you may + use L{get_exception} to get more detailed error information. + + Since 1.1, if no event is passed, this method will block until the + authentication succeeds or fails. On failure, an exception is raised. + Otherwise, the method simply returns. + + If the server requires multi-step authentication (which is very rare), + this method will return a list of auth types permissible for the next + step. Otherwise, in the normal case, an empty list is returned. + + @param username: the username to authenticate as + @type username: string + @param key: the private key to authenticate with + @type key: L{PKey <pkey.PKey>} + @param event: an event to trigger when the authentication attempt is + complete (whether it was successful or not) + @type event: threading.Event + @return: list of auth types permissible for the next stage of + authentication (normally empty). + @rtype: list + + @raise BadAuthenticationType: if public-key authentication isn't + allowed by the server for this user (and no event was passed in). + @raise SSHException: if the authentication failed (and no event was + passed in). + """ + if (not self.active) or (not self.initial_kex_done): + # we should never try to authenticate unless we're on a secure link + raise SSHException('No existing session') + if event is None: + my_event = threading.Event() + else: + my_event = event + self.auth_handler = AuthHandler(self) + self.auth_handler.auth_publickey(username, key, my_event) + if event is not None: + # caller wants to wait for event themselves + return [] + return self.auth_handler.wait_for_response(my_event) + + def auth_interactive(self, username, handler, submethods=''): + """ + Authenticate to the server interactively. A handler is used to answer + arbitrary questions from the server. On many servers, this is just a + dumb wrapper around PAM. + + This method will block until the authentication succeeds or fails, + peroidically calling the handler asynchronously to get answers to + authentication questions. The handler may be called more than once + if the server continues to ask questions. + + The handler is expected to be a callable that will handle calls of the + form: C{handler(title, instructions, prompt_list)}. The C{title} is + meant to be a dialog-window title, and the C{instructions} are user + instructions (both are strings). C{prompt_list} will be a list of + prompts, each prompt being a tuple of C{(str, bool)}. The string is + the prompt and the boolean indicates whether the user text should be + echoed. + + A sample call would thus be: + C{handler('title', 'instructions', [('Password:', False)])}. + + The handler should return a list or tuple of answers to the server's + questions. + + If the server requires multi-step authentication (which is very rare), + this method will return a list of auth types permissible for the next + step. Otherwise, in the normal case, an empty list is returned. + + @param username: the username to authenticate as + @type username: string + @param handler: a handler for responding to server questions + @type handler: callable + @param submethods: a string list of desired submethods (optional) + @type submethods: str + @return: list of auth types permissible for the next stage of + authentication (normally empty). + @rtype: list + + @raise BadAuthenticationType: if public-key authentication isn't + allowed by the server for this user + @raise SSHException: if the authentication failed + + @since: 1.5 + """ + if (not self.active) or (not self.initial_kex_done): + # we should never try to authenticate unless we're on a secure link + raise SSHException('No existing session') + my_event = threading.Event() + self.auth_handler = AuthHandler(self) + self.auth_handler.auth_interactive(username, handler, my_event, submethods) + return self.auth_handler.wait_for_response(my_event) + + def set_log_channel(self, name): + """ + Set the channel for this transport's logging. The default is + C{"paramiko.transport"} but it can be set to anything you want. + (See the C{logging} module for more info.) SSH Channels will log + to a sub-channel of the one specified. + + @param name: new channel name for logging. + @type name: str + + @since: 1.1 + """ + self.log_name = name + self.logger = util.get_logger(name) + + def get_log_channel(self): + """ + Return the channel name used for this transport's logging. + + @return: channel name. + @rtype: str + + @since: 1.2 + """ + return self.log_name + + def set_hexdump(self, hexdump): + """ + Turn on/off logging a hex dump of protocol traffic at DEBUG level in + the logs. Normally you would want this off (which is the default), + but if you are debugging something, it may be useful. + + @param hexdump: C{True} to log protocol traffix (in hex) to the log; + C{False} otherwise. + @type hexdump: bool + """ + self.packetizer.set_hexdump(hexdump) + + def get_hexdump(self): + """ + Return C{True} if the transport is currently logging hex dumps of + protocol traffic. + + @return: C{True} if hex dumps are being logged + @rtype: bool + + @since: 1.4 + """ + return self.packetizer.get_hexdump() + + def use_compression(self, compress=True): + """ + Turn on/off compression. This will only have an affect before starting + the transport (ie before calling L{connect}, etc). By default, + compression is off since it negatively affects interactive sessions + and is not fully tested. + + @param compress: C{True} to ask the remote client/server to compress + traffic; C{False} to refuse compression + @type compress: bool + + @since: 1.5.2 + """ + if compress: + self._preferred_compression = ( 'zlib@openssh.com', 'zlib', 'none' ) + else: + self._preferred_compression = ( 'none', ) + + def stop_thread(self): + self.active = False + self.packetizer.close() + + + ### internals... + + + def _log(self, level, msg): + if issubclass(type(msg), list): + for m in msg: + self.logger.log(level, m) + else: + self.logger.log(level, msg) + + def _get_modulus_pack(self): + "used by KexGex to find primes for group exchange" + return self._modulus_pack + + def _unlink_channel(self, chanid): + "used by a Channel to remove itself from the active channel list" + try: + self.lock.acquire() + if self.channels.has_key(chanid): + del self.channels[chanid] + finally: + self.lock.release() + + def _send_message(self, data): + self.packetizer.send_message(data) + + def _send_user_message(self, data): + """ + send a message, but block if we're in key negotiation. this is used + for user-initiated requests. + """ + while True: + self.clear_to_send.wait(0.1) + if not self.active: + self._log(DEBUG, 'Dropping user packet because connection is dead.') + return + self.clear_to_send_lock.acquire() + if self.clear_to_send.isSet(): + break + self.clear_to_send_lock.release() + try: + self._send_message(data) + finally: + self.clear_to_send_lock.release() + + def _set_K_H(self, k, h): + "used by a kex object to set the K (root key) and H (exchange hash)" + self.K = k + self.H = h + if self.session_id == None: + self.session_id = h + + def _expect_packet(self, type): + "used by a kex object to register the next packet type it expects to see" + self.expected_packet = type + + def _verify_key(self, host_key, sig): + key = self._key_info[self.host_key_type](Message(host_key)) + if key is None: + raise SSHException('Unknown host key type') + if not key.verify_ssh_sig(self.H, Message(sig)): + raise SSHException('Signature verification (%s) failed. Boo. Robey should debug this.' % self.host_key_type) + self.host_key = key + + def _compute_key(self, id, nbytes): + "id is 'A' - 'F' for the various keys used by ssh" + m = Message() + m.add_mpint(self.K) + m.add_bytes(self.H) + m.add_byte(id) + m.add_bytes(self.session_id) + out = sofar = SHA.new(str(m)).digest() + while len(out) < nbytes: + m = Message() + m.add_mpint(self.K) + m.add_bytes(self.H) + m.add_bytes(sofar) + hash = SHA.new(str(m)).digest() + out += hash + sofar += hash + return out[:nbytes] + + def _get_cipher(self, name, key, iv): + if not self._cipher_info.has_key(name): + raise SSHException('Unknown client cipher ' + name) + return self._cipher_info[name]['class'].new(key, self._cipher_info[name]['mode'], iv) + + def run(self): + # (use the exposed "run" method, because if we specify a thread target + # of a private method, threading.Thread will keep a reference to it + # indefinitely, creating a GC cycle and not letting Transport ever be + # GC'd. it's a bug in Thread.) + + # active=True occurs before the thread is launched, to avoid a race + _active_threads.append(self) + if self.server_mode: + self._log(DEBUG, 'starting thread (server mode): %s' % hex(long(id(self)) & 0xffffffffL)) + else: + self._log(DEBUG, 'starting thread (client mode): %s' % hex(long(id(self)) & 0xffffffffL)) + try: + self.packetizer.write_all(self.local_version + '\r\n') + self._check_banner() + self._send_kex_init() + self.expected_packet = MSG_KEXINIT + + while self.active: + if self.packetizer.need_rekey() and not self.in_kex: + self._send_kex_init() + try: + ptype, m = self.packetizer.read_message() + except NeedRekeyException: + continue + if ptype == MSG_IGNORE: + continue + elif ptype == MSG_DISCONNECT: + self._parse_disconnect(m) + self.active = False + self.packetizer.close() + break + elif ptype == MSG_DEBUG: + self._parse_debug(m) + continue + if self.expected_packet != 0: + if ptype != self.expected_packet: + raise SSHException('Expecting packet %d, got %d' % (self.expected_packet, ptype)) + self.expected_packet = 0 + if (ptype >= 30) and (ptype <= 39): + self.kex_engine.parse_next(ptype, m) + continue + + if self._handler_table.has_key(ptype): + self._handler_table[ptype](self, m) + elif self._channel_handler_table.has_key(ptype): + chanid = m.get_int() + if self.channels.has_key(chanid): + self._channel_handler_table[ptype](self.channels[chanid], m) + elif self.channels_seen.has_key(chanid): + self._log(DEBUG, 'Ignoring message for dead channel %d' % chanid) + else: + self._log(ERROR, 'Channel request for unknown channel %d' % chanid) + self.active = False + self.packetizer.close() + elif (self.auth_handler is not None) and self.auth_handler._handler_table.has_key(ptype): + self.auth_handler._handler_table[ptype](self.auth_handler, m) + else: + self._log(WARNING, 'Oops, unhandled type %d' % ptype) + msg = Message() + msg.add_byte(chr(MSG_UNIMPLEMENTED)) + msg.add_int(m.seqno) + self._send_message(msg) + except SSHException, e: + self._log(ERROR, 'Exception: ' + str(e)) + self._log(ERROR, util.tb_strings()) + self.saved_exception = e + except EOFError, e: + self._log(DEBUG, 'EOF in transport thread') + #self._log(DEBUG, util.tb_strings()) + self.saved_exception = e + except socket.error, e: + if type(e.args) is tuple: + emsg = '%s (%d)' % (e.args[1], e.args[0]) + else: + emsg = e.args + self._log(ERROR, 'Socket exception: ' + emsg) + self.saved_exception = e + except Exception, e: + self._log(ERROR, 'Unknown exception: ' + str(e)) + self._log(ERROR, util.tb_strings()) + self.saved_exception = e + _active_threads.remove(self) + for chan in self.channels.values(): + chan._unlink() + if self.active: + self.active = False + self.packetizer.close() + if self.completion_event != None: + self.completion_event.set() + if self.auth_handler is not None: + self.auth_handler.abort() + for event in self.channel_events.values(): + event.set() + self.sock.close() + + + ### protocol stages + + + def _negotiate_keys(self, m): + # throws SSHException on anything unusual + self.clear_to_send_lock.acquire() + try: + self.clear_to_send.clear() + finally: + self.clear_to_send_lock.release() + if self.local_kex_init == None: + # remote side wants to renegotiate + self._send_kex_init() + self._parse_kex_init(m) + self.kex_engine.start_kex() + + def _check_banner(self): + # this is slow, but we only have to do it once + for i in range(5): + # give them 5 seconds for the first line, then just 2 seconds each additional line + if i == 0: + timeout = 5 + else: + timeout = 2 + try: + buffer = self.packetizer.readline(timeout) + except Exception, x: + raise SSHException('Error reading SSH protocol banner' + str(x)) + if buffer[:4] == 'SSH-': + break + self._log(DEBUG, 'Banner: ' + buffer) + if buffer[:4] != 'SSH-': + raise SSHException('Indecipherable protocol version "' + buffer + '"') + # save this server version string for later + self.remote_version = buffer + # pull off any attached comment + comment = '' + i = string.find(buffer, ' ') + if i >= 0: + comment = buffer[i+1:] + buffer = buffer[:i] + # parse out version string and make sure it matches + segs = buffer.split('-', 2) + if len(segs) < 3: + raise SSHException('Invalid SSH banner') + version = segs[1] + client = segs[2] + if version != '1.99' and version != '2.0': + raise SSHException('Incompatible version (%s instead of 2.0)' % (version,)) + self._log(INFO, 'Connected (version %s, client %s)' % (version, client)) + + def _send_kex_init(self): + """ + announce to the other side that we'd like to negotiate keys, and what + kind of key negotiation we support. + """ + self.clear_to_send_lock.acquire() + try: + self.clear_to_send.clear() + finally: + self.clear_to_send_lock.release() + self.in_kex = True + if self.server_mode: + if (self._modulus_pack is None) and ('diffie-hellman-group-exchange-sha1' in self._preferred_kex): + # can't do group-exchange if we don't have a pack of potential primes + pkex = list(self.get_security_options().kex) + pkex.remove('diffie-hellman-group-exchange-sha1') + self.get_security_options().kex = pkex + available_server_keys = filter(self.server_key_dict.keys().__contains__, + self._preferred_keys) + else: + available_server_keys = self._preferred_keys + + randpool.stir() + m = Message() + m.add_byte(chr(MSG_KEXINIT)) + m.add_bytes(randpool.get_bytes(16)) + m.add_list(self._preferred_kex) + m.add_list(available_server_keys) + m.add_list(self._preferred_ciphers) + m.add_list(self._preferred_ciphers) + m.add_list(self._preferred_macs) + m.add_list(self._preferred_macs) + m.add_list(self._preferred_compression) + m.add_list(self._preferred_compression) + m.add_string('') + m.add_string('') + m.add_boolean(False) + m.add_int(0) + # save a copy for later (needed to compute a hash) + self.local_kex_init = str(m) + self._send_message(m) + + def _parse_kex_init(self, m): + cookie = m.get_bytes(16) + kex_algo_list = m.get_list() + server_key_algo_list = m.get_list() + client_encrypt_algo_list = m.get_list() + server_encrypt_algo_list = m.get_list() + client_mac_algo_list = m.get_list() + server_mac_algo_list = m.get_list() + client_compress_algo_list = m.get_list() + server_compress_algo_list = m.get_list() + client_lang_list = m.get_list() + server_lang_list = m.get_list() + kex_follows = m.get_boolean() + unused = m.get_int() + + self._log(DEBUG, 'kex algos:' + str(kex_algo_list) + ' server key:' + str(server_key_algo_list) + \ + ' client encrypt:' + str(client_encrypt_algo_list) + \ + ' server encrypt:' + str(server_encrypt_algo_list) + \ + ' client mac:' + str(client_mac_algo_list) + \ + ' server mac:' + str(server_mac_algo_list) + \ + ' client compress:' + str(client_compress_algo_list) + \ + ' server compress:' + str(server_compress_algo_list) + \ + ' client lang:' + str(client_lang_list) + \ + ' server lang:' + str(server_lang_list) + \ + ' kex follows?' + str(kex_follows)) + + # as a server, we pick the first item in the client's list that we support. + # as a client, we pick the first item in our list that the server supports. + if self.server_mode: + agreed_kex = filter(self._preferred_kex.__contains__, kex_algo_list) + else: + agreed_kex = filter(kex_algo_list.__contains__, self._preferred_kex) + if len(agreed_kex) == 0: + raise SSHException('Incompatible ssh peer (no acceptable kex algorithm)') + self.kex_engine = self._kex_info[agreed_kex[0]](self) + + if self.server_mode: + available_server_keys = filter(self.server_key_dict.keys().__contains__, + self._preferred_keys) + agreed_keys = filter(available_server_keys.__contains__, server_key_algo_list) + else: + agreed_keys = filter(server_key_algo_list.__contains__, self._preferred_keys) + if len(agreed_keys) == 0: + raise SSHException('Incompatible ssh peer (no acceptable host key)') + self.host_key_type = agreed_keys[0] + if self.server_mode and (self.get_server_key() is None): + raise SSHException('Incompatible ssh peer (can\'t match requested host key type)') + + if self.server_mode: + agreed_local_ciphers = filter(self._preferred_ciphers.__contains__, + server_encrypt_algo_list) + agreed_remote_ciphers = filter(self._preferred_ciphers.__contains__, + client_encrypt_algo_list) + else: + agreed_local_ciphers = filter(client_encrypt_algo_list.__contains__, + self._preferred_ciphers) + agreed_remote_ciphers = filter(server_encrypt_algo_list.__contains__, + self._preferred_ciphers) + if (len(agreed_local_ciphers) == 0) or (len(agreed_remote_ciphers) == 0): + raise SSHException('Incompatible ssh server (no acceptable ciphers)') + self.local_cipher = agreed_local_ciphers[0] + self.remote_cipher = agreed_remote_ciphers[0] + self._log(DEBUG, 'Ciphers agreed: local=%s, remote=%s' % (self.local_cipher, self.remote_cipher)) + + if self.server_mode: + agreed_remote_macs = filter(self._preferred_macs.__contains__, client_mac_algo_list) + agreed_local_macs = filter(self._preferred_macs.__contains__, server_mac_algo_list) + else: + agreed_local_macs = filter(client_mac_algo_list.__contains__, self._preferred_macs) + agreed_remote_macs = filter(server_mac_algo_list.__contains__, self._preferred_macs) + if (len(agreed_local_macs) == 0) or (len(agreed_remote_macs) == 0): + raise SSHException('Incompatible ssh server (no acceptable macs)') + self.local_mac = agreed_local_macs[0] + self.remote_mac = agreed_remote_macs[0] + + if self.server_mode: + agreed_remote_compression = filter(self._preferred_compression.__contains__, client_compress_algo_list) + agreed_local_compression = filter(self._preferred_compression.__contains__, server_compress_algo_list) + else: + agreed_local_compression = filter(client_compress_algo_list.__contains__, self._preferred_compression) + agreed_remote_compression = filter(server_compress_algo_list.__contains__, self._preferred_compression) + if (len(agreed_local_compression) == 0) or (len(agreed_remote_compression) == 0): + raise SSHException('Incompatible ssh server (no acceptable compression) %r %r %r' % (agreed_local_compression, agreed_remote_compression, self._preferred_compression)) + self.local_compression = agreed_local_compression[0] + self.remote_compression = agreed_remote_compression[0] + + self._log(DEBUG, 'using kex %s; server key type %s; cipher: local %s, remote %s; mac: local %s, remote %s; compression: local %s, remote %s' % + (agreed_kex[0], self.host_key_type, self.local_cipher, self.remote_cipher, self.local_mac, + self.remote_mac, self.local_compression, self.remote_compression)) + + # save for computing hash later... + # now wait! openssh has a bug (and others might too) where there are + # actually some extra bytes (one NUL byte in openssh's case) added to + # the end of the packet but not parsed. turns out we need to throw + # away those bytes because they aren't part of the hash. + self.remote_kex_init = chr(MSG_KEXINIT) + m.get_so_far() + + def _activate_inbound(self): + "switch on newly negotiated encryption parameters for inbound traffic" + block_size = self._cipher_info[self.remote_cipher]['block-size'] + if self.server_mode: + IV_in = self._compute_key('A', block_size) + key_in = self._compute_key('C', self._cipher_info[self.remote_cipher]['key-size']) + else: + IV_in = self._compute_key('B', block_size) + key_in = self._compute_key('D', self._cipher_info[self.remote_cipher]['key-size']) + engine = self._get_cipher(self.remote_cipher, key_in, IV_in) + mac_size = self._mac_info[self.remote_mac]['size'] + mac_engine = self._mac_info[self.remote_mac]['class'] + # initial mac keys are done in the hash's natural size (not the potentially truncated + # transmission size) + if self.server_mode: + mac_key = self._compute_key('E', mac_engine.digest_size) + else: + mac_key = self._compute_key('F', mac_engine.digest_size) + self.packetizer.set_inbound_cipher(engine, block_size, mac_engine, mac_size, mac_key) + compress_in = self._compression_info[self.remote_compression][1] + if (compress_in is not None) and ((self.remote_compression != 'zlib@openssh.com') or self.authenticated): + self._log(DEBUG, 'Switching on inbound compression ...') + self.packetizer.set_inbound_compressor(compress_in()) + + def _activate_outbound(self): + "switch on newly negotiated encryption parameters for outbound traffic" + m = Message() + m.add_byte(chr(MSG_NEWKEYS)) + self._send_message(m) + block_size = self._cipher_info[self.local_cipher]['block-size'] + if self.server_mode: + IV_out = self._compute_key('B', block_size) + key_out = self._compute_key('D', self._cipher_info[self.local_cipher]['key-size']) + else: + IV_out = self._compute_key('A', block_size) + key_out = self._compute_key('C', self._cipher_info[self.local_cipher]['key-size']) + engine = self._get_cipher(self.local_cipher, key_out, IV_out) + mac_size = self._mac_info[self.local_mac]['size'] + mac_engine = self._mac_info[self.local_mac]['class'] + # initial mac keys are done in the hash's natural size (not the potentially truncated + # transmission size) + if self.server_mode: + mac_key = self._compute_key('F', mac_engine.digest_size) + else: + mac_key = self._compute_key('E', mac_engine.digest_size) + self.packetizer.set_outbound_cipher(engine, block_size, mac_engine, mac_size, mac_key) + compress_out = self._compression_info[self.local_compression][0] + if (compress_out is not None) and ((self.local_compression != 'zlib@openssh.com') or self.authenticated): + self._log(DEBUG, 'Switching on outbound compression ...') + self.packetizer.set_outbound_compressor(compress_out()) + if not self.packetizer.need_rekey(): + self.in_kex = False + # we always expect to receive NEWKEYS now + self.expected_packet = MSG_NEWKEYS + + def _auth_trigger(self): + self.authenticated = True + # delayed initiation of compression + if self.local_compression == 'zlib@openssh.com': + compress_out = self._compression_info[self.local_compression][0] + self._log(DEBUG, 'Switching on outbound compression ...') + self.packetizer.set_outbound_compressor(compress_out()) + if self.remote_compression == 'zlib@openssh.com': + compress_in = self._compression_info[self.remote_compression][1] + self._log(DEBUG, 'Switching on inbound compression ...') + self.packetizer.set_inbound_compressor(compress_in()) + + def _parse_newkeys(self, m): + self._log(DEBUG, 'Switch to new keys ...') + self._activate_inbound() + # can also free a bunch of stuff here + self.local_kex_init = self.remote_kex_init = None + self.K = None + self.kex_engine = None + if self.server_mode and (self.auth_handler is None): + # create auth handler for server mode + self.auth_handler = AuthHandler(self) + if not self.initial_kex_done: + # this was the first key exchange + self.initial_kex_done = True + # send an event? + if self.completion_event != None: + self.completion_event.set() + # it's now okay to send data again (if this was a re-key) + if not self.packetizer.need_rekey(): + self.in_kex = False + self.clear_to_send_lock.acquire() + try: + self.clear_to_send.set() + finally: + self.clear_to_send_lock.release() + return + + def _parse_disconnect(self, m): + code = m.get_int() + desc = m.get_string() + self._log(INFO, 'Disconnect (code %d): %s' % (code, desc)) + + def _parse_global_request(self, m): + kind = m.get_string() + self._log(DEBUG, 'Received global request "%s"' % kind) + want_reply = m.get_boolean() + ok = self.server_object.check_global_request(kind, m) + extra = () + if type(ok) is tuple: + extra = ok + ok = True + if want_reply: + msg = Message() + if ok: + msg.add_byte(chr(MSG_REQUEST_SUCCESS)) + msg.add(*extra) + else: + msg.add_byte(chr(MSG_REQUEST_FAILURE)) + self._send_message(msg) + + def _parse_request_success(self, m): + self._log(DEBUG, 'Global request successful.') + self.global_response = m + if self.completion_event is not None: + self.completion_event.set() + + def _parse_request_failure(self, m): + self._log(DEBUG, 'Global request denied.') + self.global_response = None + if self.completion_event is not None: + self.completion_event.set() + + def _parse_channel_open_success(self, m): + chanid = m.get_int() + server_chanid = m.get_int() + server_window_size = m.get_int() + server_max_packet_size = m.get_int() + if not self.channels.has_key(chanid): + self._log(WARNING, 'Success for unrequested channel! [??]') + return + self.lock.acquire() + try: + chan = self.channels[chanid] + chan._set_remote_channel(server_chanid, server_window_size, server_max_packet_size) + self._log(INFO, 'Secsh channel %d opened.' % chanid) + if self.channel_events.has_key(chanid): + self.channel_events[chanid].set() + del self.channel_events[chanid] + finally: + self.lock.release() + return + + def _parse_channel_open_failure(self, m): + chanid = m.get_int() + reason = m.get_int() + reason_str = m.get_string() + lang = m.get_string() + if CONNECTION_FAILED_CODE.has_key(reason): + reason_text = CONNECTION_FAILED_CODE[reason] + else: + reason_text = '(unknown code)' + self._log(INFO, 'Secsh channel %d open FAILED: %s: %s' % (chanid, reason_str, reason_text)) + try: + self.lock.aquire() + if self.channels.has_key(chanid): + del self.channels[chanid] + if self.channel_events.has_key(chanid): + self.channel_events[chanid].set() + del self.channel_events[chanid] + finally: + self.lock.release() + return + + def _parse_channel_open(self, m): + kind = m.get_string() + chanid = m.get_int() + initial_window_size = m.get_int() + max_packet_size = m.get_int() + reject = False + if not self.server_mode: + self._log(DEBUG, 'Rejecting "%s" channel request from server.' % kind) + reject = True + reason = OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED + else: + self.lock.acquire() + try: + my_chanid = self.channel_counter + while self.channels.has_key(my_chanid): + self.channel_counter = (self.channel_counter + 1) & 0xffffff + my_chanid = self.channel_counter + self.channel_counter = (self.channel_counter + 1) & 0xffffff + finally: + self.lock.release() + reason = self.server_object.check_channel_request(kind, my_chanid) + if reason != OPEN_SUCCEEDED: + self._log(DEBUG, 'Rejecting "%s" channel request from client.' % kind) + reject = True + if reject: + msg = Message() + msg.add_byte(chr(MSG_CHANNEL_OPEN_FAILURE)) + msg.add_int(chanid) + msg.add_int(reason) + msg.add_string('') + msg.add_string('en') + self._send_message(msg) + return + chan = Channel(my_chanid) + try: + self.lock.acquire() + self.channels[my_chanid] = chan + self.channels_seen[my_chanid] = True + chan._set_transport(self) + chan._set_window(self.window_size, self.max_packet_size) + chan._set_remote_channel(chanid, initial_window_size, max_packet_size) + finally: + self.lock.release() + m = Message() + m.add_byte(chr(MSG_CHANNEL_OPEN_SUCCESS)) + m.add_int(chanid) + m.add_int(my_chanid) + m.add_int(self.window_size) + m.add_int(self.max_packet_size) + self._send_message(m) + self._log(INFO, 'Secsh channel %d opened.' % my_chanid) + try: + self.lock.acquire() + self.server_accepts.append(chan) + self.server_accept_cv.notify() + finally: + self.lock.release() + + def _parse_debug(self, m): + always_display = m.get_boolean() + msg = m.get_string() + lang = m.get_string() + self._log(DEBUG, 'Debug msg: ' + util.safe_string(msg)) + + def _get_subsystem_handler(self, name): + try: + self.lock.acquire() + if not self.subsystem_table.has_key(name): + return (None, [], {}) + return self.subsystem_table[name] + finally: + self.lock.release() + + _handler_table = { + MSG_NEWKEYS: _parse_newkeys, + MSG_GLOBAL_REQUEST: _parse_global_request, + MSG_REQUEST_SUCCESS: _parse_request_success, + MSG_REQUEST_FAILURE: _parse_request_failure, + MSG_CHANNEL_OPEN_SUCCESS: _parse_channel_open_success, + MSG_CHANNEL_OPEN_FAILURE: _parse_channel_open_failure, + MSG_CHANNEL_OPEN: _parse_channel_open, + MSG_KEXINIT: _negotiate_keys, + } + + _channel_handler_table = { + MSG_CHANNEL_SUCCESS: Channel._request_success, + MSG_CHANNEL_FAILURE: Channel._request_failed, + MSG_CHANNEL_DATA: Channel._feed, + MSG_CHANNEL_EXTENDED_DATA: Channel._feed_extended, + MSG_CHANNEL_WINDOW_ADJUST: Channel._window_adjust, + MSG_CHANNEL_REQUEST: Channel._handle_request, + MSG_CHANNEL_EOF: Channel._handle_eof, + MSG_CHANNEL_CLOSE: Channel._handle_close, + } diff --git a/paramiko/util.py b/paramiko/util.py new file mode 100644 index 0000000..abab825 --- /dev/null +++ b/paramiko/util.py @@ -0,0 +1,357 @@ +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# This file is part of paramiko. +# +# Paramiko is free software; you can redistribute it and/or modify it under the +# terms of the GNU Lesser General Public License as published by the Free +# Software Foundation; either version 2.1 of the License, or (at your option) +# any later version. +# +# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY +# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +# details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Useful functions used by the rest of paramiko. +""" + +from __future__ import generators + +import fnmatch +import sys +import struct +import traceback +import threading + +from paramiko.common import * + + +# Change by RogerB - python < 2.3 doesn't have enumerate so we implement it +if sys.version_info < (2,3): + class enumerate: + def __init__ (self, sequence): + self.sequence = sequence + def __iter__ (self): + count = 0 + for item in self.sequence: + yield (count, item) + count += 1 + + +def inflate_long(s, always_positive=False): + "turns a normalized byte string into a long-int (adapted from Crypto.Util.number)" + out = 0L + negative = 0 + if not always_positive and (len(s) > 0) and (ord(s[0]) >= 0x80): + negative = 1 + if len(s) % 4: + filler = '\x00' + if negative: + filler = '\xff' + s = filler * (4 - len(s) % 4) + s + for i in range(0, len(s), 4): + out = (out << 32) + struct.unpack('>I', s[i:i+4])[0] + if negative: + out -= (1L << (8 * len(s))) + return out + +def deflate_long(n, add_sign_padding=True): + "turns a long-int into a normalized byte string (adapted from Crypto.Util.number)" + # after much testing, this algorithm was deemed to be the fastest + s = '' + n = long(n) + while (n != 0) and (n != -1): + s = struct.pack('>I', n & 0xffffffffL) + s + n = n >> 32 + # strip off leading zeros, FFs + for i in enumerate(s): + if (n == 0) and (i[1] != '\000'): + break + if (n == -1) and (i[1] != '\xff'): + break + else: + # degenerate case, n was either 0 or -1 + i = (0,) + if n == 0: + s = '\000' + else: + s = '\xff' + s = s[i[0]:] + if add_sign_padding: + if (n == 0) and (ord(s[0]) >= 0x80): + s = '\x00' + s + if (n == -1) and (ord(s[0]) < 0x80): + s = '\xff' + s + return s + +def format_binary_weird(data): + out = '' + for i in enumerate(data): + out += '%02X' % ord(i[1]) + if i[0] % 2: + out += ' ' + if i[0] % 16 == 15: + out += '\n' + return out + +def format_binary(data, prefix=''): + x = 0 + out = [] + while len(data) > x + 16: + out.append(format_binary_line(data[x:x+16])) + x += 16 + if x < len(data): + out.append(format_binary_line(data[x:])) + return [prefix + x for x in out] + +def format_binary_line(data): + left = ' '.join(['%02X' % ord(c) for c in data]) + right = ''.join([('.%c..' % c)[(ord(c)+63)//95] for c in data]) + return '%-50s %s' % (left, right) + +def hexify(s): + "turn a string into a hex sequence" + return ''.join(['%02X' % ord(c) for c in s]) + +def unhexify(s): + "turn a hex sequence back into a string" + return ''.join([chr(int(s[i:i+2], 16)) for i in range(0, len(s), 2)]) + +def safe_string(s): + out = '' + for c in s: + if (ord(c) >= 32) and (ord(c) <= 127): + out += c + else: + out += '%%%02X' % ord(c) + return out + +# ''.join([['%%%02X' % ord(c), c][(ord(c) >= 32) and (ord(c) <= 127)] for c in s]) + +def bit_length(n): + norm = deflate_long(n, 0) + hbyte = ord(norm[0]) + bitlen = len(norm) * 8 + while not (hbyte & 0x80): + hbyte <<= 1 + bitlen -= 1 + return bitlen + +def tb_strings(): + return ''.join(traceback.format_exception(*sys.exc_info())).split('\n') + +def generate_key_bytes(hashclass, salt, key, nbytes): + """ + Given a password, passphrase, or other human-source key, scramble it + through a secure hash into some keyworthy bytes. This specific algorithm + is used for encrypting/decrypting private key files. + + @param hashclass: class from L{Crypto.Hash} that can be used as a secure + hashing function (like C{MD5} or C{SHA}). + @type hashclass: L{Crypto.Hash} + @param salt: data to salt the hash with. + @type salt: string + @param key: human-entered password or passphrase. + @type key: string + @param nbytes: number of bytes to generate. + @type nbytes: int + @return: key data + @rtype: string + """ + keydata = '' + digest = '' + if len(salt) > 8: + salt = salt[:8] + while nbytes > 0: + hash = hashclass.new() + if len(digest) > 0: + hash.update(digest) + hash.update(key) + hash.update(salt) + digest = hash.digest() + size = min(nbytes, len(digest)) + keydata += digest[:size] + nbytes -= size + return keydata + +def load_host_keys(filename): + """ + Read a file of known SSH host keys, in the format used by openssh, and + return a compound dict of C{hostname -> keytype ->} L{PKey <paramiko.pkey.PKey>}. + The hostname may be an IP address or DNS name. The keytype will be either + C{"ssh-rsa"} or C{"ssh-dss"}. + + This type of file unfortunately doesn't exist on Windows, but on posix, + it will usually be stored in C{os.path.expanduser("~/.ssh/known_hosts")}. + + @param filename: name of the file to read host keys from + @type filename: str + @return: dict of host keys, indexed by hostname and then keytype + @rtype: dict(hostname, dict(keytype, L{PKey <paramiko.pkey.PKey>})) + """ + import base64 + from rsakey import RSAKey + from dsskey import DSSKey + + keys = {} + f = file(filename, 'r') + for line in f: + line = line.strip() + if (len(line) == 0) or (line[0] == '#'): + continue + keylist = line.split(' ') + if len(keylist) != 3: + continue + hostlist, keytype, key = keylist + hosts = hostlist.split(',') + for host in hosts: + if not keys.has_key(host): + keys[host] = {} + if keytype == 'ssh-rsa': + keys[host][keytype] = RSAKey(data=base64.decodestring(key)) + elif keytype == 'ssh-dss': + keys[host][keytype] = DSSKey(data=base64.decodestring(key)) + f.close() + return keys + +def parse_ssh_config(file_obj): + """ + Parse a config file of the format used by OpenSSH, and return an object + that can be used to make queries to L{lookup_ssh_host_config}. The + format is described in OpenSSH's C{ssh_config} man page. This method is + provided primarily as a convenience to posix users (since the OpenSSH + format is a de-facto standard on posix) but should work fine on Windows + too. + + The return value is currently a list of dictionaries, each containing + host-specific configuration, but this is considered an implementation + detail and may be subject to change in later versions. + + @param file_obj: a file-like object to read the config file from + @type file_obj: file + @return: opaque configuration object + @rtype: object + """ + ret = [] + config = { 'host': '*' } + ret.append(config) + + for line in file_obj: + line = line.rstrip('\n').lstrip() + if (line == '') or (line[0] == '#'): + continue + if '=' in line: + key, value = line.split('=', 1) + key = key.strip().lower() + else: + # find first whitespace, and split there + i = 0 + while (i < len(line)) and not line[i].isspace(): + i += 1 + if i == len(line): + raise Exception('Unparsable line: %r' % line) + key = line[:i].lower() + value = line[i:].lstrip() + + if key == 'host': + # do we have a pre-existing host config to append to? + matches = [c for c in ret if c['host'] == value] + if len(matches) > 0: + config = matches[0] + else: + config = { 'host': value } + ret.append(config) + else: + config[key] = value + + return ret + +def lookup_ssh_host_config(hostname, config): + """ + Return a dict of config options for a given hostname. The C{config} object + must come from L{parse_ssh_config}. + + The host-matching rules of OpenSSH's C{ssh_config} man page are used, which + means that all configuration options from matching host specifications are + merged, with more specific hostmasks taking precedence. In other words, if + C{"Port"} is set under C{"Host *"} and also C{"Host *.example.com"}, and + the lookup is for C{"ssh.example.com"}, then the port entry for + C{"Host *.example.com"} will win out. + + The keys in the returned dict are all normalized to lowercase (look for + C{"port"}, not C{"Port"}. No other processing is done to the keys or + values. + + @param hostname: the hostname to lookup + @type hostname: str + @param config: the config object to search + @type config: object + """ + matches = [x for x in config if fnmatch.fnmatch(hostname, x['host'])] + # sort in order of shortest match (usually '*') to longest + matches.sort(key=lambda x: len(x['host'])) + ret = {} + for m in matches: + ret.update(m) + del ret['host'] + return ret + +def mod_inverse(x, m): + # it's crazy how small python can make this function. + u1, u2, u3 = 1, 0, m + v1, v2, v3 = 0, 1, x + + while v3 > 0: + q = u3 // v3 + u1, v1 = v1, u1 - v1 * q + u2, v2 = v2, u2 - v2 * q + u3, v3 = v3, u3 - v3 * q + if u2 < 0: + u2 += m + return u2 + +_g_thread_ids = {} +_g_thread_counter = 0 +_g_thread_lock = threading.Lock() +def get_thread_id(): + global _g_thread_ids, _g_thread_counter, _g_thread_lock + tid = id(threading.currentThread()) + try: + return _g_thread_ids[tid] + except KeyError: + _g_thread_lock.acquire() + try: + _g_thread_counter += 1 + ret = _g_thread_ids[tid] = _g_thread_counter + finally: + _g_thread_lock.release() + return ret + +def log_to_file(filename, level=DEBUG): + "send paramiko logs to a logfile, if they're not already going somewhere" + l = logging.getLogger("paramiko") + if len(l.handlers) > 0: + return + l.setLevel(level) + f = open(filename, 'w') + lh = logging.StreamHandler(f) + lh.setFormatter(logging.Formatter('%(levelname)-.3s [%(asctime)s.%(msecs)03d] thr=%(_threadid)-3d %(name)s: %(message)s', + '%Y%m%d-%H:%M:%S')) + l.addHandler(lh) + +# make only one filter object, so it doesn't get applied more than once +class PFilter (object): + def filter(self, record): + record._threadid = get_thread_id() + return True +_pfilter = PFilter() + +def get_logger(name): + l = logging.getLogger(name) + l.addFilter(_pfilter) + return l |