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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import absolute_import, division, print_function
import datetime
import warnings
from cryptography import utils, x509
from cryptography.exceptions import UnsupportedAlgorithm
from cryptography.hazmat.primitives import hashes
def _obj2txt(backend, obj):
# Set to 80 on the recommendation of
# https://www.openssl.org/docs/crypto/OBJ_nid2ln.html#return_values
buf_len = 80
buf = backend._ffi.new("char[]", buf_len)
res = backend._lib.OBJ_obj2txt(buf, buf_len, obj, 1)
assert res > 0
return backend._ffi.buffer(buf, res)[:].decode()
def _build_x509_name(backend, x509_name):
count = backend._lib.X509_NAME_entry_count(x509_name)
attributes = []
for x in range(count):
entry = backend._lib.X509_NAME_get_entry(x509_name, x)
obj = backend._lib.X509_NAME_ENTRY_get_object(entry)
assert obj != backend._ffi.NULL
data = backend._lib.X509_NAME_ENTRY_get_data(entry)
assert data != backend._ffi.NULL
buf = backend._ffi.new("unsigned char **")
res = backend._lib.ASN1_STRING_to_UTF8(buf, data)
assert res >= 0
assert buf[0] != backend._ffi.NULL
buf = backend._ffi.gc(
buf, lambda buf: backend._lib.OPENSSL_free(buf[0])
)
value = backend._ffi.buffer(buf[0], res)[:].decode('utf8')
oid = _obj2txt(backend, obj)
attributes.append(
x509.NameAttribute(
x509.ObjectIdentifier(oid), value
)
)
return x509.Name(attributes)
@utils.register_interface(x509.Certificate)
class _Certificate(object):
def __init__(self, backend, x509):
self._backend = backend
self._x509 = x509
def fingerprint(self, algorithm):
h = hashes.Hash(algorithm, self._backend)
bio = self._backend._create_mem_bio()
res = self._backend._lib.i2d_X509_bio(
bio, self._x509
)
assert res == 1
der = self._backend._read_mem_bio(bio)
h.update(der)
return h.finalize()
@property
def version(self):
version = self._backend._lib.X509_get_version(self._x509)
if version == 0:
return x509.Version.v1
elif version == 2:
return x509.Version.v3
else:
raise x509.InvalidVersion(
"{0} is not a valid X509 version".format(version), version
)
@property
def serial(self):
asn1_int = self._backend._lib.X509_get_serialNumber(self._x509)
assert asn1_int != self._backend._ffi.NULL
bn = self._backend._lib.ASN1_INTEGER_to_BN(
asn1_int, self._backend._ffi.NULL
)
assert bn != self._backend._ffi.NULL
bn = self._backend._ffi.gc(bn, self._backend._lib.BN_free)
return self._backend._bn_to_int(bn)
def public_key(self):
pkey = self._backend._lib.X509_get_pubkey(self._x509)
assert pkey != self._backend._ffi.NULL
pkey = self._backend._ffi.gc(pkey, self._backend._lib.EVP_PKEY_free)
return self._backend._evp_pkey_to_public_key(pkey)
@property
def not_valid_before(self):
asn1_time = self._backend._lib.X509_get_notBefore(self._x509)
return self._parse_asn1_time(asn1_time)
@property
def not_valid_after(self):
asn1_time = self._backend._lib.X509_get_notAfter(self._x509)
return self._parse_asn1_time(asn1_time)
def _parse_asn1_time(self, asn1_time):
assert asn1_time != self._backend._ffi.NULL
generalized_time = self._backend._lib.ASN1_TIME_to_generalizedtime(
asn1_time, self._backend._ffi.NULL
)
assert generalized_time != self._backend._ffi.NULL
generalized_time = self._backend._ffi.gc(
generalized_time, self._backend._lib.ASN1_GENERALIZEDTIME_free
)
time = self._backend._ffi.string(
self._backend._lib.ASN1_STRING_data(
self._backend._ffi.cast("ASN1_STRING *", generalized_time)
)
).decode("ascii")
return datetime.datetime.strptime(time, "%Y%m%d%H%M%SZ")
@property
def issuer(self):
issuer = self._backend._lib.X509_get_issuer_name(self._x509)
assert issuer != self._backend._ffi.NULL
return _build_x509_name(self._backend, issuer)
@property
def subject(self):
subject = self._backend._lib.X509_get_subject_name(self._x509)
assert subject != self._backend._ffi.NULL
return _build_x509_name(self._backend, subject)
@property
def signature_hash_algorithm(self):
oid = _obj2txt(self._backend, self._x509.sig_alg.algorithm)
try:
return x509._SIG_OIDS_TO_HASH[oid]
except KeyError:
raise UnsupportedAlgorithm(
"Signature algorithm OID:{0} not recognized".format(oid)
)
@property
def extensions(self):
extensions = []
seen_oids = set()
extcount = self._backend._lib.X509_get_ext_count(self._x509)
for i in range(0, extcount):
ext = self._backend._lib.X509_get_ext(self._x509, i)
assert ext != self._backend._ffi.NULL
crit = self._backend._lib.X509_EXTENSION_get_critical(ext)
critical = crit == 1
oid = x509.ObjectIdentifier(_obj2txt(self._backend, ext.object))
if oid in seen_oids:
raise x509.DuplicateExtension(
"Duplicate {0} extension found".format(oid), oid
)
elif oid == x509.OID_BASIC_CONSTRAINTS and critical:
# TODO: remove this obviously.
warnings.warn(
"Extension support is not fully implemented. A basic "
"constraints extension with the critical flag was seen and"
" IGNORED."
)
elif critical:
raise x509.UnsupportedExtension(
"{0} is not currently supported".format(oid), oid
)
else:
# Unsupported non-critical extension, silently skipping for now
seen_oids.add(oid)
continue
seen_oids.add(oid)
return x509.Extensions(extensions)
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