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Diffstat (limited to 'paramiko/ecdsakey.py')
| -rw-r--r-- | paramiko/ecdsakey.py | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/paramiko/ecdsakey.py b/paramiko/ecdsakey.py new file mode 100644 index 0000000..ac840ab --- /dev/null +++ b/paramiko/ecdsakey.py @@ -0,0 +1,181 @@ +# Copyright (C) 2003-2007 Robey Pointer <robeypointer@gmail.com> +# +# 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{ECDSAKey} +""" + +import binascii +from ecdsa import SigningKey, VerifyingKey, der, curves +from ecdsa.util import number_to_string, sigencode_string, sigencode_strings, sigdecode_strings +from Crypto.Hash import SHA256, 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 ECDSAKey (PKey): + """ + Representation of an ECDSA key which can be used to sign and verify SSH2 + data. + """ + + def __init__(self, msg=None, data=None, filename=None, password=None, vals=None, file_obj=None): + self.verifying_key = None + self.signing_key = None + if file_obj is not None: + self._from_private_key(file_obj, password) + return + 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.verifying_key, self.signing_key = vals + else: + if msg is None: + raise SSHException('Key object may not be empty') + if msg.get_string() != 'ecdsa-sha2-nistp256': + raise SSHException('Invalid key') + curvename = msg.get_string() + if curvename != 'nistp256': + raise SSHException("Can't handle curve of type %s" % curvename) + + pointinfo = msg.get_string() + if pointinfo[0] != "\x04": + raise SSHException('Point compression is being used: %s'% + binascii.hexlify(pointinfo)) + self.verifying_key = VerifyingKey.from_string(pointinfo[1:], + curve=curves.NIST256p) + self.size = 256 + + def __str__(self): + key = self.verifying_key + m = Message() + m.add_string('ecdsa-sha2-nistp256') + m.add_string('nistp256') + + point_str = "\x04" + key.to_string() + + m.add_string(point_str) + return str(m) + + def __hash__(self): + h = hash(self.get_name()) + h = h * 37 + hash(self.verifying_key.pubkey.point.x()) + h = h * 37 + hash(self.verifying_key.pubkey.point.y()) + return hash(h) + + def get_name(self): + return 'ecdsa-sha2-nistp256' + + def get_bits(self): + return self.size + + def can_sign(self): + return self.signing_key is not None + + def sign_ssh_data(self, rpool, data): + digest = SHA256.new(data).digest() + sig = self.signing_key.sign_digest(digest, entropy=rpool.read, + sigencode=self._sigencode) + m = Message() + m.add_string('ecdsa-sha2-nistp256') + m.add_string(sig) + return m + + def verify_ssh_sig(self, data, msg): + if msg.get_string() != 'ecdsa-sha2-nistp256': + return False + sig = msg.get_string() + + # verify the signature by SHA'ing the data and encrypting it + # using the public key. + hash_obj = SHA256.new(data).digest() + return self.verifying_key.verify_digest(sig, hash_obj, + sigdecode=self._sigdecode) + + def write_private_key_file(self, filename, password=None): + key = self.signing_key or self.verifying_key + self._write_private_key_file('EC', filename, key.to_der(), password) + + def write_private_key(self, file_obj, password=None): + key = self.signing_key or self.verifying_key + self._write_private_key('EC', file_obj, key.to_der(), 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} + """ + signing_key = ECDSA.generate() + key = ECDSAKey(vals=(signing_key, signing_key.get_verifying_key())) + return key + generate = staticmethod(generate) + + + ### internals... + + + def _from_private_key_file(self, filename, password): + data = self._read_private_key_file('EC', filename, password) + self._decode_key(data) + + def _from_private_key(self, file_obj, password): + data = self._read_private_key('EC', file_obj, password) + self._decode_key(data) + + ALLOWED_PADDINGS = ['\x01', '\x02\x02', '\x03\x03\x03', '\x04\x04\x04\x04', + '\x05\x05\x05\x05\x05', '\x06\x06\x06\x06\x06\x06', + '\x07\x07\x07\x07\x07\x07\x07'] + def _decode_key(self, data): + s, padding = der.remove_sequence(data) + if padding: + if padding not in self.ALLOWED_PADDINGS: + raise ValueError, "weird padding: %s" % (binascii.hexlify(empty)) + data = data[:-len(padding)] + key = SigningKey.from_der(data) + self.signing_key = key + self.verifying_key = key.get_verifying_key() + self.size = 256 + + def _sigencode(self, r, s, order): + msg = Message() + msg.add_mpint(r) + msg.add_mpint(s) + return str(msg) + + def _sigdecode(self, sig, order): + msg = Message(sig) + r = msg.get_mpint() + s = msg.get_mpint() + return (r, s) |