forked from LIMXTEC/BitCore
-
Notifications
You must be signed in to change notification settings - Fork 0
/
key.py
232 lines (180 loc) · 8.29 KB
/
key.py
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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
# Copyright (c) 2011 Sam Rushing
"""ECC secp256k1 OpenSSL wrapper.
WARNING: This module does not mlock() secrets; your private keys may end up on
disk in swap! Use with caution!
This file is modified from python-bitcorelib.
"""
import ctypes
import ctypes.util
import hashlib
import sys
ssl = ctypes.cdll.LoadLibrary(ctypes.util.find_library ('ssl') or 'libeay32')
ssl.BN_new.restype = ctypes.c_void_p
ssl.BN_new.argtypes = []
ssl.BN_bin2bn.restype = ctypes.c_void_p
ssl.BN_bin2bn.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.c_void_p]
ssl.BN_CTX_free.restype = None
ssl.BN_CTX_free.argtypes = [ctypes.c_void_p]
ssl.BN_CTX_new.restype = ctypes.c_void_p
ssl.BN_CTX_new.argtypes = []
ssl.ECDH_compute_key.restype = ctypes.c_int
ssl.ECDH_compute_key.argtypes = [ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p]
ssl.ECDSA_sign.restype = ctypes.c_int
ssl.ECDSA_sign.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
ssl.ECDSA_verify.restype = ctypes.c_int
ssl.ECDSA_verify.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p]
ssl.EC_KEY_free.restype = None
ssl.EC_KEY_free.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
ssl.EC_KEY_new_by_curve_name.argtypes = [ctypes.c_int]
ssl.EC_KEY_get0_group.restype = ctypes.c_void_p
ssl.EC_KEY_get0_group.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_get0_public_key.restype = ctypes.c_void_p
ssl.EC_KEY_get0_public_key.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_set_private_key.restype = ctypes.c_int
ssl.EC_KEY_set_private_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.EC_KEY_set_conv_form.restype = None
ssl.EC_KEY_set_conv_form.argtypes = [ctypes.c_void_p, ctypes.c_int]
ssl.EC_KEY_set_public_key.restype = ctypes.c_int
ssl.EC_KEY_set_public_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.i2o_ECPublicKey.restype = ctypes.c_void_p
ssl.i2o_ECPublicKey.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.EC_POINT_new.restype = ctypes.c_void_p
ssl.EC_POINT_new.argtypes = [ctypes.c_void_p]
ssl.EC_POINT_free.restype = None
ssl.EC_POINT_free.argtypes = [ctypes.c_void_p]
ssl.EC_POINT_mul.restype = ctypes.c_int
ssl.EC_POINT_mul.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
# this specifies the curve used with ECDSA.
NID_secp256k1 = 714 # from openssl/obj_mac.h
SECP256K1_ORDER = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141
SECP256K1_ORDER_HALF = SECP256K1_ORDER // 2
# Thx to Sam Devlin for the ctypes magic 64-bit fix.
def _check_result(val, func, args):
if val == 0:
raise ValueError
else:
return ctypes.c_void_p (val)
ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
ssl.EC_KEY_new_by_curve_name.errcheck = _check_result
class CECKey(object):
"""Wrapper around OpenSSL's EC_KEY"""
POINT_CONVERSION_COMPRESSED = 2
POINT_CONVERSION_UNCOMPRESSED = 4
def __init__(self):
self.k = ssl.EC_KEY_new_by_curve_name(NID_secp256k1)
def __del__(self):
if ssl:
ssl.EC_KEY_free(self.k)
self.k = None
def set_secretbytes(self, secret):
priv_key = ssl.BN_bin2bn(secret, 32, ssl.BN_new())
group = ssl.EC_KEY_get0_group(self.k)
pub_key = ssl.EC_POINT_new(group)
ctx = ssl.BN_CTX_new()
if not ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx):
raise ValueError("Could not derive public key from the supplied secret.")
ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx)
ssl.EC_KEY_set_private_key(self.k, priv_key)
ssl.EC_KEY_set_public_key(self.k, pub_key)
ssl.EC_POINT_free(pub_key)
ssl.BN_CTX_free(ctx)
return self.k
def set_privkey(self, key):
self.mb = ctypes.create_string_buffer(key)
return ssl.d2i_ECPrivateKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
def set_pubkey(self, key):
self.mb = ctypes.create_string_buffer(key)
return ssl.o2i_ECPublicKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
def get_privkey(self):
size = ssl.i2d_ECPrivateKey(self.k, 0)
mb_pri = ctypes.create_string_buffer(size)
ssl.i2d_ECPrivateKey(self.k, ctypes.byref(ctypes.pointer(mb_pri)))
return mb_pri.raw
def get_pubkey(self):
size = ssl.i2o_ECPublicKey(self.k, 0)
mb = ctypes.create_string_buffer(size)
ssl.i2o_ECPublicKey(self.k, ctypes.byref(ctypes.pointer(mb)))
return mb.raw
def get_raw_ecdh_key(self, other_pubkey):
ecdh_keybuffer = ctypes.create_string_buffer(32)
r = ssl.ECDH_compute_key(ctypes.pointer(ecdh_keybuffer), 32,
ssl.EC_KEY_get0_public_key(other_pubkey.k),
self.k, 0)
if r != 32:
raise Exception('CKey.get_ecdh_key(): ECDH_compute_key() failed')
return ecdh_keybuffer.raw
def get_ecdh_key(self, other_pubkey, kdf=lambda k: hashlib.sha256(k).digest()):
# FIXME: be warned it's not clear what the kdf should be as a default
r = self.get_raw_ecdh_key(other_pubkey)
return kdf(r)
def sign(self, hash, low_s = True):
# FIXME: need unit tests for below cases
if not isinstance(hash, bytes):
raise TypeError('Hash must be bytes instance; got %r' % hash.__class__)
if len(hash) != 32:
raise ValueError('Hash must be exactly 32 bytes long')
sig_size0 = ctypes.c_uint32()
sig_size0.value = ssl.ECDSA_size(self.k)
mb_sig = ctypes.create_string_buffer(sig_size0.value)
result = ssl.ECDSA_sign(0, hash, len(hash), mb_sig, ctypes.byref(sig_size0), self.k)
assert 1 == result
assert mb_sig.raw[0] == 0x30
assert mb_sig.raw[1] == sig_size0.value - 2
total_size = mb_sig.raw[1]
assert mb_sig.raw[2] == 2
r_size = mb_sig.raw[3]
assert mb_sig.raw[4 + r_size] == 2
s_size = mb_sig.raw[5 + r_size]
s_value = int.from_bytes(mb_sig.raw[6+r_size:6+r_size+s_size], byteorder='big')
if (not low_s) or s_value <= SECP256K1_ORDER_HALF:
return mb_sig.raw[:sig_size0.value]
else:
low_s_value = SECP256K1_ORDER - s_value
low_s_bytes = (low_s_value).to_bytes(33, byteorder='big')
while len(low_s_bytes) > 1 and low_s_bytes[0] == 0 and low_s_bytes[1] < 0x80:
low_s_bytes = low_s_bytes[1:]
new_s_size = len(low_s_bytes)
new_total_size_byte = (total_size + new_s_size - s_size).to_bytes(1,byteorder='big')
new_s_size_byte = (new_s_size).to_bytes(1,byteorder='big')
return b'\x30' + new_total_size_byte + mb_sig.raw[2:5+r_size] + new_s_size_byte + low_s_bytes
def verify(self, hash, sig):
"""Verify a DER signature"""
return ssl.ECDSA_verify(0, hash, len(hash), sig, len(sig), self.k) == 1
def set_compressed(self, compressed):
if compressed:
form = self.POINT_CONVERSION_COMPRESSED
else:
form = self.POINT_CONVERSION_UNCOMPRESSED
ssl.EC_KEY_set_conv_form(self.k, form)
class CPubKey(bytes):
"""An encapsulated public key
Attributes:
is_valid - Corresponds to CPubKey.IsValid()
is_fullyvalid - Corresponds to CPubKey.IsFullyValid()
is_compressed - Corresponds to CPubKey.IsCompressed()
"""
def __new__(cls, buf, _cec_key=None):
self = super(CPubKey, cls).__new__(cls, buf)
if _cec_key is None:
_cec_key = CECKey()
self._cec_key = _cec_key
self.is_fullyvalid = _cec_key.set_pubkey(self) != 0
return self
@property
def is_valid(self):
return len(self) > 0
@property
def is_compressed(self):
return len(self) == 33
def verify(self, hash, sig):
return self._cec_key.verify(hash, sig)
def __str__(self):
return repr(self)
def __repr__(self):
# Always have represent as b'<secret>' so test cases don't have to
# change for py2/3
if sys.version > '3':
return '%s(%s)' % (self.__class__.__name__, super(CPubKey, self).__repr__())
else:
return '%s(b%s)' % (self.__class__.__name__, super(CPubKey, self).__repr__())