/usr/lib/python2.7/dist-packages/cryptography/hazmat/backends/openssl/dh.py is in python-cryptography 2.1.4-1ubuntu1.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 | # This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
from cryptography import utils
from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import dh
def _dh_params_dup(dh_cdata, backend):
lib = backend._lib
ffi = backend._ffi
param_cdata = lib.DHparams_dup(dh_cdata)
backend.openssl_assert(param_cdata != ffi.NULL)
param_cdata = ffi.gc(param_cdata, lib.DH_free)
if lib.OPENSSL_VERSION_NUMBER < 0x10002000 or lib.CRYPTOGRAPHY_IS_LIBRESSL:
# In OpenSSL versions < 1.0.2 or libressl DHparams_dup don't copy q
q = ffi.new("BIGNUM **")
lib.DH_get0_pqg(dh_cdata, ffi.NULL, q, ffi.NULL)
q_dup = lib.BN_dup(q[0])
res = lib.DH_set0_pqg(param_cdata, ffi.NULL, q_dup, ffi.NULL)
backend.openssl_assert(res == 1)
return param_cdata
def _dh_cdata_to_parameters(dh_cdata, backend):
param_cdata = _dh_params_dup(dh_cdata, backend)
return _DHParameters(backend, param_cdata)
@utils.register_interface(dh.DHParametersWithSerialization)
class _DHParameters(object):
def __init__(self, backend, dh_cdata):
self._backend = backend
self._dh_cdata = dh_cdata
def parameter_numbers(self):
p = self._backend._ffi.new("BIGNUM **")
g = self._backend._ffi.new("BIGNUM **")
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata, p, q, g)
self._backend.openssl_assert(p[0] != self._backend._ffi.NULL)
self._backend.openssl_assert(g[0] != self._backend._ffi.NULL)
if q[0] == self._backend._ffi.NULL:
q_val = None
else:
q_val = self._backend._bn_to_int(q[0])
return dh.DHParameterNumbers(
p=self._backend._bn_to_int(p[0]),
g=self._backend._bn_to_int(g[0]),
q=q_val
)
def generate_private_key(self):
return self._backend.generate_dh_private_key(self)
def parameter_bytes(self, encoding, format):
if format is not serialization.ParameterFormat.PKCS3:
raise ValueError(
"Only PKCS3 serialization is supported"
)
if not self._backend._lib.Cryptography_HAS_EVP_PKEY_DHX:
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata,
self._backend._ffi.NULL,
q,
self._backend._ffi.NULL)
if q[0] != self._backend._ffi.NULL:
raise UnsupportedAlgorithm(
"DH X9.42 serialization is not supported",
_Reasons.UNSUPPORTED_SERIALIZATION)
return self._backend._parameter_bytes(
encoding,
format,
self._dh_cdata
)
def _handle_dh_compute_key_error(errors, backend):
lib = backend._lib
backend.openssl_assert(
errors[0]._lib_reason_match(
lib.ERR_LIB_DH, lib.DH_R_INVALID_PUBKEY
)
)
raise ValueError("Public key value is invalid for this exchange.")
def _get_dh_num_bits(backend, dh_cdata):
p = backend._ffi.new("BIGNUM **")
backend._lib.DH_get0_pqg(dh_cdata, p,
backend._ffi.NULL,
backend._ffi.NULL)
backend.openssl_assert(p[0] != backend._ffi.NULL)
return backend._lib.BN_num_bits(p[0])
@utils.register_interface(dh.DHPrivateKeyWithSerialization)
class _DHPrivateKey(object):
def __init__(self, backend, dh_cdata, evp_pkey):
self._backend = backend
self._dh_cdata = dh_cdata
self._evp_pkey = evp_pkey
self._key_size_bytes = self._backend._lib.DH_size(dh_cdata)
@property
def key_size(self):
return _get_dh_num_bits(self._backend, self._dh_cdata)
def private_numbers(self):
p = self._backend._ffi.new("BIGNUM **")
g = self._backend._ffi.new("BIGNUM **")
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata, p, q, g)
self._backend.openssl_assert(p[0] != self._backend._ffi.NULL)
self._backend.openssl_assert(g[0] != self._backend._ffi.NULL)
if q[0] == self._backend._ffi.NULL:
q_val = None
else:
q_val = self._backend._bn_to_int(q[0])
pub_key = self._backend._ffi.new("BIGNUM **")
priv_key = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_key(self._dh_cdata, pub_key, priv_key)
self._backend.openssl_assert(pub_key[0] != self._backend._ffi.NULL)
self._backend.openssl_assert(priv_key[0] != self._backend._ffi.NULL)
return dh.DHPrivateNumbers(
public_numbers=dh.DHPublicNumbers(
parameter_numbers=dh.DHParameterNumbers(
p=self._backend._bn_to_int(p[0]),
g=self._backend._bn_to_int(g[0]),
q=q_val
),
y=self._backend._bn_to_int(pub_key[0])
),
x=self._backend._bn_to_int(priv_key[0])
)
def exchange(self, peer_public_key):
buf = self._backend._ffi.new("unsigned char[]", self._key_size_bytes)
pub_key = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_key(peer_public_key._dh_cdata, pub_key,
self._backend._ffi.NULL)
self._backend.openssl_assert(pub_key[0] != self._backend._ffi.NULL)
res = self._backend._lib.DH_compute_key(
buf,
pub_key[0],
self._dh_cdata
)
if res == -1:
errors = self._backend._consume_errors()
return _handle_dh_compute_key_error(errors, self._backend)
else:
self._backend.openssl_assert(res >= 1)
key = self._backend._ffi.buffer(buf)[:res]
pad = self._key_size_bytes - len(key)
if pad > 0:
key = (b"\x00" * pad) + key
return key
def public_key(self):
dh_cdata = _dh_params_dup(self._dh_cdata, self._backend)
pub_key = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_key(self._dh_cdata,
pub_key, self._backend._ffi.NULL)
self._backend.openssl_assert(pub_key[0] != self._backend._ffi.NULL)
pub_key_dup = self._backend._lib.BN_dup(pub_key[0])
self._backend.openssl_assert(pub_key_dup != self._backend._ffi.NULL)
res = self._backend._lib.DH_set0_key(dh_cdata,
pub_key_dup,
self._backend._ffi.NULL)
self._backend.openssl_assert(res == 1)
evp_pkey = self._backend._dh_cdata_to_evp_pkey(dh_cdata)
return _DHPublicKey(self._backend, dh_cdata, evp_pkey)
def parameters(self):
return _dh_cdata_to_parameters(self._dh_cdata, self._backend)
def private_bytes(self, encoding, format, encryption_algorithm):
if format is not serialization.PrivateFormat.PKCS8:
raise ValueError(
"DH private keys support only PKCS8 serialization"
)
if not self._backend._lib.Cryptography_HAS_EVP_PKEY_DHX:
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata,
self._backend._ffi.NULL,
q,
self._backend._ffi.NULL)
if q[0] != self._backend._ffi.NULL:
raise UnsupportedAlgorithm(
"DH X9.42 serialization is not supported",
_Reasons.UNSUPPORTED_SERIALIZATION)
return self._backend._private_key_bytes(
encoding,
format,
encryption_algorithm,
self._evp_pkey,
self._dh_cdata
)
@utils.register_interface(dh.DHPublicKeyWithSerialization)
class _DHPublicKey(object):
def __init__(self, backend, dh_cdata, evp_pkey):
self._backend = backend
self._dh_cdata = dh_cdata
self._evp_pkey = evp_pkey
self._key_size_bits = _get_dh_num_bits(self._backend, self._dh_cdata)
@property
def key_size(self):
return self._key_size_bits
def public_numbers(self):
p = self._backend._ffi.new("BIGNUM **")
g = self._backend._ffi.new("BIGNUM **")
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata, p, q, g)
self._backend.openssl_assert(p[0] != self._backend._ffi.NULL)
self._backend.openssl_assert(g[0] != self._backend._ffi.NULL)
if q[0] == self._backend._ffi.NULL:
q_val = None
else:
q_val = self._backend._bn_to_int(q[0])
pub_key = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_key(self._dh_cdata,
pub_key, self._backend._ffi.NULL)
self._backend.openssl_assert(pub_key[0] != self._backend._ffi.NULL)
return dh.DHPublicNumbers(
parameter_numbers=dh.DHParameterNumbers(
p=self._backend._bn_to_int(p[0]),
g=self._backend._bn_to_int(g[0]),
q=q_val
),
y=self._backend._bn_to_int(pub_key[0])
)
def parameters(self):
return _dh_cdata_to_parameters(self._dh_cdata, self._backend)
def public_bytes(self, encoding, format):
if format is not serialization.PublicFormat.SubjectPublicKeyInfo:
raise ValueError(
"DH public keys support only "
"SubjectPublicKeyInfo serialization"
)
if not self._backend._lib.Cryptography_HAS_EVP_PKEY_DHX:
q = self._backend._ffi.new("BIGNUM **")
self._backend._lib.DH_get0_pqg(self._dh_cdata,
self._backend._ffi.NULL,
q,
self._backend._ffi.NULL)
if q[0] != self._backend._ffi.NULL:
raise UnsupportedAlgorithm(
"DH X9.42 serialization is not supported",
_Reasons.UNSUPPORTED_SERIALIZATION)
return self._backend._public_key_bytes(
encoding,
format,
self,
self._evp_pkey,
None
)
|