Introduce ECDSA

This just adds tests; hooking this up with paramiko comes in the next
commit.
This commit is contained in:
Ethan Glasser-Camp 2013-03-24 17:13:50 -04:00
parent 0392e3df8f
commit 632129c427
7 changed files with 261 additions and 3 deletions

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@ -69,6 +69,7 @@ from ssh_exception import SSHException, PasswordRequiredException, \
from server import ServerInterface, SubsystemHandler, InteractiveQuery
from rsakey import RSAKey
from dsskey import DSSKey
from ecdsakey import ECDSAKey
from sftp import SFTPError, BaseSFTP
from sftp_client import SFTP, SFTPClient
from sftp_server import SFTPServer

181
paramiko/ecdsakey.py Normal file
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@ -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)

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@ -1,2 +1,3 @@
pycrypto
tox
ecdsa

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@ -40,7 +40,9 @@ import sys
try:
from setuptools import setup
kw = {
'install_requires': 'pycrypto >= 2.1, != 2.4',
'install_requires': ['pycrypto >= 2.1, != 2.4',
'ecdsa',
],
}
except ImportError:
from distutils.core import setup

5
tests/test_ecdsa.key Normal file
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@ -0,0 +1,5 @@
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIKB6ty3yVyKEnfF/zprx0qwC76MsMlHY4HXCnqho2eKioAoGCCqGSM49
AwEHoUQDQgAElI9mbdlaS+T9nHxY/59lFnn80EEecZDBHq4gLpccY8Mge5ZTMiMD
ADRvOqQ5R98Sxst765CAqXmRtz8vwoD96g==
-----END EC PRIVATE KEY-----

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@ -0,0 +1,8 @@
-----BEGIN EC PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,EEB56BC745EDB2DE04FC3FE1F8DA387E
wdt7QTCa6ahTJLaEPH7NhHyBcxhzrzf93d4UwQOuAhkM6//jKD4lF9fErHBW0f3B
ExberCU3UxfEF3xX2thXiLw47JgeOCeQUlqRFx92p36k6YmfNGX6W8CsZ3d+XodF
Z+pb6m285CiSX+W95NenFMexXFsIpntiCvTifTKJ8os=
-----END EC PRIVATE KEY-----

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@ -23,14 +23,17 @@ Some unit tests for public/private key objects.
from binascii import hexlify, unhexlify
import StringIO
import unittest
from paramiko import RSAKey, DSSKey, Message, util
from paramiko import RSAKey, DSSKey, ECDSAKey, Message, util
from paramiko.common import rng
# from openssh's ssh-keygen
PUB_RSA = 'ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEA049W6geFpmsljTwfvI1UmKWWJPNFI74+vNKTk4dmzkQY2yAMs6FhlvhlI8ysU4oj71ZsRYMecHbBbxdN79+JRFVYTKaLqjwGENeTd+yv4q+V2PvZv3fLnzApI3l7EJCqhWwJUHJ1jAkZzqDx0tyOL4uoZpww3nmE0kb3y21tH4c='
PUB_DSS = 'ssh-dss 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'
PUB_ECDSA = 'ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBJSPZm3ZWkvk/Zx8WP+fZRZ5/NBBHnGQwR6uIC6XHGPDIHuWUzIjAwA0bzqkOUffEsbLe+uQgKl5kbc/L8KA/eo='
FINGER_RSA = '1024 60:73:38:44:cb:51:86:65:7f:de:da:a2:2b:5a:57:d5'
FINGER_DSS = '1024 44:78:f0:b9:a2:3c:c5:18:20:09:ff:75:5b:c1:d2:6c'
FINGER_ECDSA = '256 25:19:eb:55:e6:a1:47:ff:4f:38:d2:75:6f:a5:d5:60'
SIGNED_RSA = '20:d7:8a:31:21:cb:f7:92:12:f2:a4:89:37:f5:78:af:e6:16:b6:25:b9:97:3d:a2:cd:5f:ca:20:21:73:4c:ad:34:73:8f:20:77:28:e2:94:15:08:d8:91:40:7a:85:83:bf:18:37:95:dc:54:1a:9b:88:29:6c:73:ca:38:b4:04:f1:56:b9:f2:42:9d:52:1b:29:29:b4:4f:fd:c9:2d:af:47:d2:40:76:30:f3:63:45:0c:d9:1d:43:86:0f:1c:70:e2:93:12:34:f3:ac:c5:0a:2f:14:50:66:59:f1:88:ee:c1:4a:e9:d1:9c:4e:46:f0:0e:47:6f:38:74:f1:44:a8'
RSA_PRIVATE_OUT = """\
@ -66,6 +69,13 @@ QPSch9pT9XHqn+1rZ4bK+QGA
-----END DSA PRIVATE KEY-----
"""
ECDSA_PRIVATE_OUT = """\
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIKB6ty3yVyKEnfF/zprx0qwC76MsMlHY4HXCnqho2eKioAoGCCqGSM49
AwEHoUQDQgAElI9mbdlaS+T9nHxY/59lFnn80EEecZDBHq4gLpccY8Mge5ZTMiMD
ADRvOqQ5R98Sxst765CAqXmRtz8vwoD96g==
-----END EC PRIVATE KEY-----
"""
class KeyTest (unittest.TestCase):
@ -188,3 +198,53 @@ class KeyTest (unittest.TestCase):
msg = key.sign_ssh_data(rng, 'jerri blank')
msg.rewind()
self.assert_(key.verify_ssh_sig('jerri blank', msg))
def test_10_load_ecdsa(self):
key = ECDSAKey.from_private_key_file('tests/test_ecdsa.key')
self.assertEquals('ecdsa-sha2-nistp256', key.get_name())
exp_ecdsa = FINGER_ECDSA.split()[1].replace(':', '')
my_ecdsa = hexlify(key.get_fingerprint())
self.assertEquals(exp_ecdsa, my_ecdsa)
self.assertEquals(PUB_ECDSA.split()[1], key.get_base64())
self.assertEquals(256, key.get_bits())
s = StringIO.StringIO()
key.write_private_key(s)
self.assertEquals(ECDSA_PRIVATE_OUT, s.getvalue())
s.seek(0)
key2 = ECDSAKey.from_private_key(s)
self.assertEquals(key, key2)
def test_11_load_ecdsa_password(self):
key = ECDSAKey.from_private_key_file('tests/test_ecdsa_password.key', 'television')
self.assertEquals('ecdsa-sha2-nistp256', key.get_name())
exp_ecdsa = FINGER_ECDSA.split()[1].replace(':', '')
my_ecdsa = hexlify(key.get_fingerprint())
self.assertEquals(exp_ecdsa, my_ecdsa)
self.assertEquals(PUB_ECDSA.split()[1], key.get_base64())
self.assertEquals(256, key.get_bits())
def test_12_compare_ecdsa(self):
# verify that the private & public keys compare equal
key = ECDSAKey.from_private_key_file('tests/test_ecdsa.key')
self.assertEquals(key, key)
pub = ECDSAKey(data=str(key))
self.assert_(key.can_sign())
self.assert_(not pub.can_sign())
self.assertEquals(key, pub)
def test_13_sign_ecdsa(self):
# verify that the rsa private key can sign and verify
key = ECDSAKey.from_private_key_file('tests/test_ecdsa.key')
msg = key.sign_ssh_data(rng, 'ice weasels')
self.assert_(type(msg) is Message)
msg.rewind()
self.assertEquals('ecdsa-sha2-nistp256', msg.get_string())
# ECDSA signatures, like DSS signatures, tend to be different
# each time, so we can't compare against a "known correct"
# signature.
# Even the length of the signature can change.
msg.rewind()
pub = ECDSAKey(data=str(key))
self.assert_(pub.verify_ssh_sig('ice weasels', msg))