aboutsummaryrefslogtreecommitdiff
path: root/paramiko/agent.py
diff options
context:
space:
mode:
authorJeremy T. Bouse <jbouse@debian.org>2009-11-27 16:20:09 -0500
committerJeremy T. Bouse <jbouse@debian.org>2009-11-27 16:20:09 -0500
commit176c6caf4ea7918e1698438634b237fab8456471 (patch)
tree6e2a8e5be1af2a6ec324fdbf99589aa099f1ec2a /paramiko/agent.py
downloadpython-paramiko-176c6caf4ea7918e1698438634b237fab8456471.tar
python-paramiko-176c6caf4ea7918e1698438634b237fab8456471.tar.gz
Imported Upstream version 1.5.2upstream/1.5.2
Diffstat (limited to 'paramiko/agent.py')
-rw-r--r--paramiko/agent.py138
1 files changed, 138 insertions, 0 deletions
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()