1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
# 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{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, file_obj=None):
self.n = None
self.e = None
self.d = None
self.p = None
self.q = 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.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 self.d is not None
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_obj = util.inflate_long(self._pkcs1imify(SHA.new(data).digest()), True)
rsa = RSA.construct((long(self.n), long(self.e)))
return rsa.verify(hash_obj, (sig,))
def _encode_key(self):
if (self.p is None) or (self.q is None):
raise SSHException('Not enough key info to write private key file')
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')
return str(b)
def write_private_key_file(self, filename, password=None):
self._write_private_key_file('RSA', filename, self._encode_key(), password)
def write_private_key(self, file_obj, password=None):
self._write_private_key('RSA', file_obj, self._encode_key(), 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}
"""
rsa = RSA.generate(bits, rng.read, 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):
data = self._read_private_key_file('RSA', filename, password)
self._decode_key(data)
def _from_private_key(self, file_obj, password):
data = self._read_private_key('RSA', file_obj, password)
self._decode_key(data)
def _decode_key(self, data):
# private key file contains:
# RSAPrivateKey = { version = 0, n, e, d, p, q, d mod p-1, d mod q-1, q**-1 mod p }
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)
|