def testEncode1(self):
der = DerObjectId('1.2.840.113549.1.1.1')
self.assertEquals(der.encode(), b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
#
der = DerObjectId()
der.value = '1.2.840.113549.1.1.1'
self.assertEquals(der.encode(), b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
def _import_pkcs8(encoded, passphrase):
from Cryptodome.IO import PKCS8
# From RFC5915, Section 1:
#
# Distributing an EC private key with PKCS#8 [RFC5208] involves including:
# a) id-ecPublicKey, id-ecDH, or id-ecMQV (from [RFC5480]) with the
# namedCurve as the parameters in the privateKeyAlgorithm field; and
# b) ECPrivateKey in the PrivateKey field, which is an OCTET STRING.
algo_oid, private_key, params = PKCS8.unwrap(encoded, passphrase)
# We accept id-ecPublicKey, id-ecDH, id-ecMQV without making any
# distiction for now.
unrestricted_oid = "1.2.840.10045.2.1"
ecdh_oid = "1.3.132.1.12"
ecmqv_oid = "1.3.132.1.13"
if algo_oid not in (unrestricted_oid, ecdh_oid, ecmqv_oid):
raise UnsupportedEccFeature("Unsupported ECC purpose (OID: %s)" %
algo_oid)
curve_oid = DerObjectId().decode(params).value
return _import_private_der(private_key, passphrase, curve_oid)
def testEncode1(self):
der = DerObjectId('1.2.840.113549.1.1.1')
self.assertEquals(der.encode(), b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
#
der = DerObjectId()
der.value = '1.2.840.113549.1.1.1'
self.assertEquals(der.encode(), b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
def _export_subjectPublicKeyInfo(self):
# Uncompressed form
order_bytes = _curve.order.size_in_bytes()
public_key = (bchr(4) + self.pointQ.x.to_bytes(order_bytes) +
self.pointQ.y.to_bytes(order_bytes))
unrestricted_oid = "1.2.840.10045.2.1"
return _create_subject_public_key_info(unrestricted_oid, public_key,
DerObjectId(_curve.oid))
def _import_private_der(encoded, passphrase, curve_oid=None):
# See RFC5915 https://tools.ietf.org/html/rfc5915
#
# ECPrivateKey ::= SEQUENCE {
# version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
# privateKey OCTET STRING,
# parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
# publicKey [1] BIT STRING OPTIONAL
# }
private_key = DerSequence().decode(encoded, nr_elements=(3, 4))
if private_key[0] != 1:
raise ValueError("Incorrect ECC private key version")
try:
parameters = DerObjectId(explicit=0).decode(private_key[2]).value
if curve_oid is not None and parameters != curve_oid:
raise ValueError("Curve mismatch")
curve_oid = parameters
except ValueError:
pass
if curve_oid is None:
raise ValueError("No curve found")
for curve_name, curve in _curves.items():
if curve.oid == curve_oid:
break
else:
raise UnsupportedEccFeature("Unsupported ECC curve (OID: %s)" %
curve_oid)
scalar_bytes = DerOctetString().decode(private_key[1]).payload
modulus_bytes = curve.p.size_in_bytes()
if len(scalar_bytes) != modulus_bytes:
raise ValueError("Private key is too small")
d = Integer.from_bytes(scalar_bytes)
# Decode public key (if any)
if len(private_key) == 4:
public_key_enc = DerBitString(explicit=1).decode(private_key[3]).value
public_key = _import_public_der(public_key_enc, curve_oid=curve_oid)
point_x = public_key.pointQ.x
point_y = public_key.pointQ.y
else:
point_x = point_y = None
return construct(curve=curve_name, d=d, point_x=point_x, point_y=point_y)
def testDecode1(self):
# Empty sequence
der = DerObjectId()
der.decode(b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
self.assertEquals(der.value, '1.2.840.113549.1.1.1')
def testInit1(self):
der = DerObjectId("1.1")
self.assertEquals(der.encode(), b('\x06\x01)'))
def testDecode2(self):
# Verify that decode returns the object
der = DerObjectId()
self.assertEquals(der,
der.decode(b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01')))
def testDecode1(self):
# Empty sequence
der = DerObjectId()
der.decode(b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01'))
self.assertEquals(der.value, '1.2.840.113549.1.1.1')
def testInit1(self):
der = DerObjectId("1.1")
self.assertEquals(der.encode(), b('\x06\x01)'))
def _export_subjectPublicKeyInfo(self, compress):
public_key = self._export_SEC1(compress)
unrestricted_oid = "1.2.840.10045.2.1"
return _create_subject_public_key_info(unrestricted_oid, public_key,
DerObjectId(self._curve.oid))
def _EMSA_PKCS1_V1_5_ENCODE(msg_hash, emLen, with_hash_parameters=True):
"""
Implement the ``EMSA-PKCS1-V1_5-ENCODE`` function, as defined
in PKCS#1 v2.1 (RFC3447, 9.2).
``_EMSA-PKCS1-V1_5-ENCODE`` actually accepts the message ``M`` as input,
and hash it internally. Here, we expect that the message has already
been hashed instead.
:Parameters:
msg_hash : hash object
The hash object that holds the digest of the message being signed.
emLen : int
The length the final encoding must have, in bytes.
with_hash_parameters : bool
If True (default), include NULL parameters for the hash
algorithm in the ``digestAlgorithm`` SEQUENCE.
:attention: the early standard (RFC2313) stated that ``DigestInfo``
had to be BER-encoded. This means that old signatures
might have length tags in indefinite form, which
is not supported in DER. Such encoding cannot be
reproduced by this function.
:Return: An ``emLen`` byte long string that encodes the hash.
"""
# First, build the ASN.1 DER object DigestInfo:
#
# DigestInfo ::= SEQUENCE {
# digestAlgorithm AlgorithmIdentifier,
# digest OCTET STRING
# }
#
# where digestAlgorithm identifies the hash function and shall be an
# algorithm ID with an OID in the set PKCS1-v1-5DigestAlgorithms.
#
# PKCS1-v1-5DigestAlgorithms ALGORITHM-IDENTIFIER ::= {
# { OID id-md2 PARAMETERS NULL }|
# { OID id-md5 PARAMETERS NULL }|
# { OID id-sha1 PARAMETERS NULL }|
# { OID id-sha256 PARAMETERS NULL }|
# { OID id-sha384 PARAMETERS NULL }|
# { OID id-sha512 PARAMETERS NULL }
# }
#
# Appendix B.1 also says that for SHA-1/-2 algorithms, the parameters
# should be omitted. They may be present, but when they are, they shall
# have NULL value.
digestAlgo = DerSequence([DerObjectId(msg_hash.oid).encode()])
if with_hash_parameters:
digestAlgo.append(DerNull().encode())
digest = DerOctetString(msg_hash.digest())
digestInfo = DerSequence([digestAlgo.encode(), digest.encode()]).encode()
# We need at least 11 bytes for the remaining data: 3 fixed bytes and
# at least 8 bytes of padding).
if emLen < len(digestInfo) + 11:
raise TypeError(
"Selected hash algorith has a too long digest (%d bytes)." %
len(digest))
PS = b'\xFF' * (emLen - len(digestInfo) - 3)
return b'\x00\x01' + PS + b'\x00' + digestInfo
def unwrap(p8_private_key, passphrase=None):
"""Unwrap a private key from a PKCS#8 blob (clear or encrypted).
Args:
p8_private_key (byte string):
The private key wrapped into a PKCS#8 blob, DER encoded.
passphrase (byte string or string):
The passphrase to use to decrypt the blob (if it is encrypted).
Return:
A tuple containing
#. the algorithm identifier of the wrapped key (OID, dotted string)
#. the private key (byte string, DER encoded)
#. the associated parameters (byte string, DER encoded) or ``None``
Raises:
ValueError : if decoding fails
"""
if passphrase:
passphrase = tobytes(passphrase)
found = False
try:
p8_private_key = PBES1.decrypt(p8_private_key, passphrase)
found = True
except PbesError as e:
error_str = "PBES1[%s]" % str(e)
except ValueError:
error_str = "PBES1[Invalid]"
if not found:
try:
p8_private_key = PBES2.decrypt(p8_private_key, passphrase)
found = True
except PbesError as e:
error_str += ",PBES2[%s]" % str(e)
except ValueError:
error_str += ",PBES2[Invalid]"
if not found:
raise ValueError("Error decoding PKCS#8 (%s)" % error_str)
pk_info = DerSequence().decode(p8_private_key, nr_elements=(2, 3, 4))
if len(pk_info) == 2 and not passphrase:
raise ValueError("Not a valid clear PKCS#8 structure "
"(maybe it is encrypted?)")
#
# PrivateKeyInfo ::= SEQUENCE {
# version Version,
# privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
# privateKey PrivateKey,
# attributes [0] IMPLICIT Attributes OPTIONAL
# }
# Version ::= INTEGER
if pk_info[0] != 0:
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
# PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
#
# EncryptedPrivateKeyInfo ::= SEQUENCE {
# encryptionAlgorithm EncryptionAlgorithmIdentifier,
# encryptedData EncryptedData
# }
# EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
# AlgorithmIdentifier ::= SEQUENCE {
# algorithm OBJECT IDENTIFIER,
# parameters ANY DEFINED BY algorithm OPTIONAL
# }
algo = DerSequence().decode(pk_info[1], nr_elements=(1, 2))
algo_oid = DerObjectId().decode(algo[0]).value
if len(algo) == 1:
algo_params = None
else:
try:
DerNull().decode(algo[1])
algo_params = None
except:
algo_params = algo[1]
# EncryptedData ::= OCTET STRING
private_key = DerOctetString().decode(pk_info[2]).payload
return (algo_oid, private_key, algo_params)
def testDecode3(self):
der = DerObjectId()
der.decode(b('\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x00\x01'))
self.assertEquals(der.value, '1.2.840.113549.1.0.1')
def decrypt(data, passphrase):
"""Decrypt a piece of data using a passphrase and *PBES2*.
The algorithm to use is automatically detected.
:Parameters:
data : byte string
The piece of data to decrypt.
passphrase : byte string
The passphrase to use for decrypting the data.
:Returns:
The decrypted data, as a binary string.
"""
enc_private_key_info = DerSequence().decode(data, nr_elements=2)
enc_algo = DerSequence().decode(enc_private_key_info[0])
encrypted_data = DerOctetString().decode(
enc_private_key_info[1]).payload
pbe_oid = DerObjectId().decode(enc_algo[0]).value
if pbe_oid != "1.2.840.113549.1.5.13":
raise PbesError("Not a PBES2 object")
pbes2_params = DerSequence().decode(enc_algo[1], nr_elements=2)
### Key Derivation Function selection
kdf_info = DerSequence().decode(pbes2_params[0], nr_elements=2)
kdf_oid = DerObjectId().decode(kdf_info[0]).value
# We only support PBKDF2 or scrypt
if kdf_oid == "1.2.840.113549.1.5.12":
pbkdf2_params = DerSequence().decode(kdf_info[1],
nr_elements=(2, 3, 4))
salt = DerOctetString().decode(pbkdf2_params[0]).payload
iteration_count = pbkdf2_params[1]
if len(pbkdf2_params) > 2:
kdf_key_length = pbkdf2_params[2]
else:
kdf_key_length = None
if len(pbkdf2_params) > 3:
raise PbesError("Unsupported PRF for PBKDF2")
elif kdf_oid == "1.3.6.1.4.1.11591.4.11":
scrypt_params = DerSequence().decode(kdf_info[1],
nr_elements=(4, 5))
salt = DerOctetString().decode(scrypt_params[0]).payload
iteration_count, scrypt_r, scrypt_p = [
scrypt_params[x] for x in (1, 2, 3)
]
if len(scrypt_params) > 4:
kdf_key_length = scrypt_params[4]
else:
kdf_key_length = None
else:
raise PbesError("Unsupported PBES2 KDF")
### Cipher selection
enc_info = DerSequence().decode(pbes2_params[1])
enc_oid = DerObjectId().decode(enc_info[0]).value
if enc_oid == "1.2.840.113549.3.7":
# DES_EDE3_CBC
ciphermod = DES3
key_size = 24
elif enc_oid == "2.16.840.1.101.3.4.1.2":
# AES128_CBC
ciphermod = AES
key_size = 16
elif enc_oid == "2.16.840.1.101.3.4.1.22":
# AES192_CBC
ciphermod = AES
key_size = 24
elif enc_oid == "2.16.840.1.101.3.4.1.42":
# AES256_CBC
ciphermod = AES
key_size = 32
else:
raise PbesError("Unsupported PBES2 cipher")
if kdf_key_length and kdf_key_length != key_size:
raise PbesError("Mismatch between PBES2 KDF parameters"
" and selected cipher")
IV = DerOctetString().decode(enc_info[1]).payload
# Create cipher
if kdf_oid == "1.2.840.113549.1.5.12": # PBKDF2
key = PBKDF2(passphrase, salt, key_size, iteration_count)
else:
key = scrypt(passphrase, salt, key_size, iteration_count, scrypt_r,
scrypt_p)
cipher = ciphermod.new(key, ciphermod.MODE_CBC, IV)
# Decrypt data
pt = cipher.decrypt(encrypted_data)
return unpad(pt, cipher.block_size)