def testEncode6(self):
# Two positive integers
der = DerSequence()
der.append(0x180)
der.append(0xFF)
self.assertEquals(der.encode(),
b('0\x08\x02\x02\x01\x80\x02\x02\x00\xff'))
self.failUnless(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
# Two mixed integers
der = DerSequence()
der.append(2)
der.append(-2)
self.assertEquals(der.encode(), b('0\x06\x02\x01\x02\x02\x01\xFE'))
self.assertEquals(der.hasInts(), 1)
self.assertEquals(der.hasInts(False), 2)
self.failIf(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
#
der.append(0x01)
der[1:] = [9, 8]
self.assertEquals(len(der), 3)
self.assertEqual(der[1:], [9, 8])
self.assertEqual(der[1:-1], [9])
self.assertEquals(der.encode(),
b('0\x09\x02\x01\x02\x02\x01\x09\x02\x01\x08'))
def testEncode2(self):
# Indexing
der = DerSequence()
der.append(0)
der[0] = 1
self.assertEquals(len(der),1)
self.assertEquals(der[0],1)
self.assertEquals(der[-1],1)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x01'))
#
der[:] = [1]
self.assertEquals(len(der),1)
self.assertEquals(der[0],1)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x01'))
def testEncode1(self):
# Empty sequence
der = DerSequence()
self.assertEquals(der.encode(), b('0\x00'))
self.failIf(der.hasOnlyInts())
# One single-byte integer (zero)
der.append(0)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x00'))
self.assertEquals(der.hasInts(),1)
self.assertEquals(der.hasInts(False),1)
self.failUnless(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
# Invariant
self.assertEquals(der.encode(), b('0\x03\x02\x01\x00'))
def testEncode1(self):
# Empty sequence
der = DerSequence()
self.assertEquals(der.encode(), b('0\x00'))
self.failIf(der.hasOnlyInts())
# One single-byte integer (zero)
der.append(0)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x00'))
self.assertEquals(der.hasInts(), 1)
self.assertEquals(der.hasInts(False), 1)
self.failUnless(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
# Invariant
self.assertEquals(der.encode(), b('0\x03\x02\x01\x00'))
def testEncode2(self):
# Indexing
der = DerSequence()
der.append(0)
der[0] = 1
self.assertEquals(len(der), 1)
self.assertEquals(der[0], 1)
self.assertEquals(der[-1], 1)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x01'))
#
der[:] = [1]
self.assertEquals(len(der), 1)
self.assertEquals(der[0], 1)
self.assertEquals(der.encode(), b('0\x03\x02\x01\x01'))
def testEncode8(self):
# One integer and another type (yet to encode)
der = DerSequence()
der.append(0x180L)
der.append(DerSequence([5]))
self.assertEquals(der.encode(), b('0\x09\x02\x02\x01\x800\x03\x02\x01\x05'))
self.failIf(der.hasOnlyInts())
def testEncode4(self):
# One very long integer
der = DerSequence()
der.append(2**2048)
self.assertEquals(
der.encode(),
b('0\x82\x01\x05') +
b('\x02\x82\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') +
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00'))
def testEncode8(self):
# One integer and another type (yet to encode)
der = DerSequence()
der.append(0x180)
der.append(DerSequence([5]))
self.assertEquals(der.encode(), b('0\x09\x02\x02\x01\x800\x03\x02\x01\x05'))
self.failIf(der.hasOnlyInts())
def testEncode7(self):
# One integer and another type (already encoded)
der = DerSequence()
der.append(0x180)
der.append(b('0\x03\x02\x01\x05'))
self.assertEquals(der.encode(), b('0\x09\x02\x02\x01\x800\x03\x02\x01\x05'))
self.failIf(der.hasOnlyInts())
def testEncode7(self):
# One integer and another type (already encoded)
der = DerSequence()
der.append(0x180)
der.append(b('0\x03\x02\x01\x05'))
self.assertEqual(der.encode(),
b('0\x09\x02\x02\x01\x800\x03\x02\x01\x05'))
self.assertFalse(der.hasOnlyInts())
def _create_subject_public_key_info(algo_oid, secret_key, params=None):
if params is None:
params = DerNull()
spki = DerSequence([
DerSequence([DerObjectId(algo_oid), params]),
DerBitString(secret_key)
])
return spki.encode()
def _create_subject_public_key_info(algo_oid, secret_key, params=None):
if params is None:
params = DerNull()
spki = DerSequence([
DerSequence([
DerObjectId(algo_oid),
params]),
DerBitString(secret_key)
])
return spki.encode()
def testEncode6(self):
# Two positive integers
der = DerSequence()
der.append(0x180L)
der.append(0xFFL)
self.assertEquals(der.encode(), b('0\x08\x02\x02\x01\x80\x02\x02\x00\xff'))
self.failUnless(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
# Two mixed integers
der = DerSequence()
der.append(2)
der.append(-2)
self.assertEquals(der.encode(), b('0\x06\x02\x01\x02\x02\x01\xFE'))
self.assertEquals(der.hasInts(), 1)
self.assertEquals(der.hasInts(False), 2)
self.failIf(der.hasOnlyInts())
self.failUnless(der.hasOnlyInts(False))
#
der.append(0x01)
der[1:] = [9,8]
self.assertEquals(len(der),3)
self.assertEqual(der[1:],[9,8])
self.assertEqual(der[1:-1],[9])
self.assertEquals(der.encode(), b('0\x09\x02\x01\x02\x02\x01\x09\x02\x01\x08'))
def testEncode4(self):
# One very long integer
der = DerSequence()
der.append(2L**2048)
self.assertEquals(der.encode(), b('0\x82\x01\x05')+
b('\x02\x82\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')+
b('\x00\x00\x00\x00\x00\x00\x00\x00\x00'))
def encrypt(data, passphrase, protection, prot_params=None, randfunc=None):
"""Encrypt a piece of data using a passphrase and *PBES2*.
:Parameters:
data : byte string
The piece of data to encrypt.
passphrase : byte string
The passphrase to use for encrypting the data.
protection : string
The identifier of the encryption algorithm to use.
The default value is '``PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC``'.
prot_params : dictionary
Parameters of the protection algorithm.
+------------------+-----------------------------------------------+
| Key | Description |
+==================+===============================================+
| iteration_count | The KDF algorithm is repeated several times to|
| | slow down brute force attacks on passwords |
| | (called *N* or CPU/memory cost in scrypt). |
| | |
| | The default value for PBKDF2 is 1 000. |
| | The default value for scrypt is 16 384. |
+------------------+-----------------------------------------------+
| salt_size | Salt is used to thwart dictionary and rainbow |
| | attacks on passwords. The default value is 8 |
| | bytes. |
+------------------+-----------------------------------------------+
| block_size | *(scrypt only)* Memory-cost (r). The default |
| | value is 8. |
+------------------+-----------------------------------------------+
| parallelization | *(scrypt only)* CPU-cost (p). The default |
| | value is 1. |
+------------------+-----------------------------------------------+
randfunc : callable
Random number generation function; it should accept
a single integer N and return a string of random data,
N bytes long. If not specified, a new RNG will be
instantiated from ``Cryptodome.Random``.
:Returns:
The encrypted data, as a binary string.
"""
if prot_params is None:
prot_params = {}
if randfunc is None:
randfunc = Random.new().read
if protection == 'PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC':
key_size = 24
module = DES3
cipher_mode = DES3.MODE_CBC
enc_oid = _OID_DES_EDE3_CBC
elif protection in ('PBKDF2WithHMAC-SHA1AndAES128-CBC',
'scryptAndAES128-CBC'):
key_size = 16
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = _OID_AES128_CBC
elif protection in ('PBKDF2WithHMAC-SHA1AndAES192-CBC',
'scryptAndAES192-CBC'):
key_size = 24
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = _OID_AES192_CBC
elif protection in ('PBKDF2WithHMAC-SHA1AndAES256-CBC',
'scryptAndAES256-CBC'):
key_size = 32
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = _OID_AES256_CBC
else:
raise ValueError("Unknown PBES2 mode")
# Get random data
iv = randfunc(module.block_size)
salt = randfunc(prot_params.get("salt_size", 8))
# Derive key from password
if protection.startswith('PBKDF2'):
count = prot_params.get("iteration_count", 1000)
key = PBKDF2(passphrase, salt, key_size, count)
kdf_info = DerSequence([
DerObjectId(_OID_PBKDF2), # PBKDF2
DerSequence([DerOctetString(salt),
DerInteger(count)])
])
else:
# It must be scrypt
count = prot_params.get("iteration_count", 16384)
scrypt_r = prot_params.get('block_size', 8)
scrypt_p = prot_params.get('parallelization', 1)
key = scrypt(passphrase, salt, key_size, count, scrypt_r, scrypt_p)
kdf_info = DerSequence([
DerObjectId(_OID_SCRYPT), # scrypt
DerSequence([
DerOctetString(salt),
DerInteger(count),
DerInteger(scrypt_r),
DerInteger(scrypt_p)
])
])
# Create cipher and use it
cipher = module.new(key, cipher_mode, iv)
encrypted_data = cipher.encrypt(pad(data, cipher.block_size))
enc_info = DerSequence([DerObjectId(enc_oid), DerOctetString(iv)])
# Result
enc_private_key_info = DerSequence([
# encryptionAlgorithm
DerSequence([
DerObjectId(_OID_PBES2),
DerSequence([kdf_info, enc_info]),
]),
DerOctetString(encrypted_data)
])
return enc_private_key_info.encode()
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 = bchr(0xFF) * (emLen - len(digestInfo) - 3)
return b("\x00\x01") + PS + bchr(0x00) + digestInfo
def wrap(private_key,
key_oid,
passphrase=None,
protection=None,
prot_params=None,
key_params=None,
randfunc=None):
"""Wrap a private key into a PKCS#8 blob (clear or encrypted).
Args:
private_key (byte string):
The private key encoded in binary form. The actual encoding is
algorithm specific. In most cases, it is DER.
key_oid (string):
The object identifier (OID) of the private key to wrap.
It is a dotted string, like ``1.2.840.113549.1.1.1`` (for RSA keys).
passphrase (bytes string or string):
The secret passphrase from which the wrapping key is derived.
Set it only if encryption is required.
protection (string):
The identifier of the algorithm to use for securely wrapping the key.
The default value is ``PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC``.
prot_params (dictionary):
Parameters for the protection algorithm.
+------------------+-----------------------------------------------+
| Key | Description |
+==================+===============================================+
| iteration_count | The KDF algorithm is repeated several times to|
| | slow down brute force attacks on passwords |
| | (called *N* or CPU/memory cost in scrypt). |
| | The default value for PBKDF2 is 1000. |
| | The default value for scrypt is 16384. |
+------------------+-----------------------------------------------+
| salt_size | Salt is used to thwart dictionary and rainbow |
| | attacks on passwords. The default value is 8 |
| | bytes. |
+------------------+-----------------------------------------------+
| block_size | *(scrypt only)* Memory-cost (r). The default |
| | value is 8. |
+------------------+-----------------------------------------------+
| parallelization | *(scrypt only)* CPU-cost (p). The default |
| | value is 1. |
+------------------+-----------------------------------------------+
key_params (DER object):
The algorithm parameters associated to the private key.
It is required for algorithms like DSA, but not for others like RSA.
randfunc (callable):
Random number generation function; it should accept a single integer
N and return a string of random data, N bytes long.
If not specified, a new RNG will be instantiated
from :mod:`Cryptodome.Random`.
Return:
The PKCS#8-wrapped private key (possibly encrypted), as a byte string.
"""
if key_params is None:
key_params = DerNull()
#
# PrivateKeyInfo ::= SEQUENCE {
# version Version,
# privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
# privateKey PrivateKey,
# attributes [0] IMPLICIT Attributes OPTIONAL
# }
#
pk_info = DerSequence([
0,
DerSequence([DerObjectId(key_oid), key_params]),
DerOctetString(private_key)
])
pk_info_der = pk_info.encode()
if passphrase is None:
return pk_info_der
if not passphrase:
raise ValueError("Empty passphrase")
# Encryption with PBES2
passphrase = tobytes(passphrase)
if protection is None:
protection = 'PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC'
return PBES2.encrypt(pk_info_der, passphrase, protection, prot_params,
randfunc)
def encrypt(data, passphrase, protection, prot_params=None, randfunc=None):
"""Encrypt a piece of data using a passphrase and *PBES2*.
:Parameters:
data : byte string
The piece of data to encrypt.
passphrase : byte string
The passphrase to use for encrypting the data.
protection : string
The identifier of the encryption algorithm to use.
The default value is '``PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC``'.
prot_params : dictionary
Parameters of the protection algorithm.
+------------------+-----------------------------------------------+
| Key | Description |
+==================+===============================================+
| iteration_count | The KDF algorithm is repeated several times to|
| | slow down brute force attacks on passwords |
| | (called *N* or CPU/memory cost in scrypt). |
| | |
| | The default value for PBKDF2 is 1 000. |
| | The default value for scrypt is 16 384. |
+------------------+-----------------------------------------------+
| salt_size | Salt is used to thwart dictionary and rainbow |
| | attacks on passwords. The default value is 8 |
| | bytes. |
+------------------+-----------------------------------------------+
| block_size | *(scrypt only)* Memory-cost (r). The default |
| | value is 8. |
+------------------+-----------------------------------------------+
| parallelization | *(scrypt only)* CPU-cost (p). The default |
| | value is 1. |
+------------------+-----------------------------------------------+
randfunc : callable
Random number generation function; it should accept
a single integer N and return a string of random data,
N bytes long. If not specified, a new RNG will be
instantiated from ``Cryptodome.Random``.
:Returns:
The encrypted data, as a binary string.
"""
if prot_params is None:
prot_params = {}
if randfunc is None:
randfunc = Random.new().read
if protection == 'PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC':
key_size = 24
module = DES3
cipher_mode = DES3.MODE_CBC
enc_oid = "1.2.840.113549.3.7"
elif protection in ('PBKDF2WithHMAC-SHA1AndAES128-CBC',
'scryptAndAES128-CBC'):
key_size = 16
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = "2.16.840.1.101.3.4.1.2"
elif protection in ('PBKDF2WithHMAC-SHA1AndAES192-CBC',
'scryptAndAES192-CBC'):
key_size = 24
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = "2.16.840.1.101.3.4.1.22"
elif protection in ('PBKDF2WithHMAC-SHA1AndAES256-CBC',
'scryptAndAES256-CBC'):
key_size = 32
module = AES
cipher_mode = AES.MODE_CBC
enc_oid = "2.16.840.1.101.3.4.1.42"
else:
raise ValueError("Unknown PBES2 mode")
# Get random data
iv = randfunc(module.block_size)
salt = randfunc(prot_params.get("salt_size", 8))
# Derive key from password
if protection.startswith('PBKDF2'):
count = prot_params.get("iteration_count", 1000)
key = PBKDF2(passphrase, salt, key_size, count)
kdf_info = DerSequence([
DerObjectId("1.2.840.113549.1.5.12"), # PBKDF2
DerSequence([
DerOctetString(salt),
DerInteger(count)
])
])
else:
# It must be scrypt
count = prot_params.get("iteration_count", 16384)
scrypt_r = prot_params.get('block_size', 8)
scrypt_p = prot_params.get('parallelization', 1)
key = scrypt(passphrase, salt, key_size,
count, scrypt_r, scrypt_p)
kdf_info = DerSequence([
DerObjectId("1.3.6.1.4.1.11591.4.11"), # scrypt
DerSequence([
DerOctetString(salt),
DerInteger(count),
DerInteger(scrypt_r),
DerInteger(scrypt_p)
])
])
# Create cipher and use it
cipher = module.new(key, cipher_mode, iv)
encrypted_data = cipher.encrypt(pad(data, cipher.block_size))
enc_info = DerSequence([
DerObjectId(enc_oid),
DerOctetString(iv)
])
# Result
enc_private_key_info = DerSequence([
# encryptionAlgorithm
DerSequence([
DerObjectId("1.2.840.113549.1.5.13"), # PBES2
DerSequence([
kdf_info,
enc_info
]),
]),
DerOctetString(encrypted_data)
])
return enc_private_key_info.encode()
def testEncode5(self):
der = DerSequence()
der += 1
der += b('\x30\x00')
self.assertEquals(der.encode(), b('\x30\x05\x02\x01\x01\x30\x00'))
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 testEncode3(self):
# One multi-byte integer (non-zero)
der = DerSequence()
der.append(0x180)
self.assertEquals(der.encode(), b('0\x04\x02\x02\x01\x80'))
def wrap(private_key, key_oid, passphrase=None, protection=None,
prot_params=None, key_params=None, randfunc=None):
"""Wrap a private key into a PKCS#8 blob (clear or encrypted).
:Parameters:
private_key : byte string
The private key encoded in binary form. The actual encoding is
algorithm specific. In most cases, it is DER.
key_oid : string
The object identifier (OID) of the private key to wrap.
It is a dotted string, like "``1.2.840.113549.1.1.1``" (for RSA keys).
passphrase : (binary) string
The secret passphrase from which the wrapping key is derived.
Set it only if encryption is required.
protection : string
The identifier of the algorithm to use for securely wrapping the key.
The default value is '``PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC``'.
prot_params : dictionary
Parameters for the protection algorithm.
+------------------+-----------------------------------------------+
| Key | Description |
+==================+===============================================+
| iteration_count | The KDF algorithm is repeated several times to|
| | slow down brute force attacks on passwords |
| | (called *N* or CPU/memory cost in scrypt). |
| | |
| | The default value for PBKDF2 is 1 000. |
| | The default value for scrypt is 16 384. |
+------------------+-----------------------------------------------+
| salt_size | Salt is used to thwart dictionary and rainbow |
| | attacks on passwords. The default value is 8 |
| | bytes. |
+------------------+-----------------------------------------------+
| block_size | *(scrypt only)* Memory-cost (r). The default |
| | value is 8. |
+------------------+-----------------------------------------------+
| parallelization | *(scrypt only)* CPU-cost (p). The default |
| | value is 1. |
+------------------+-----------------------------------------------+
key_params : DER object
The algorithm parameters associated to the private key.
It is required for algorithms like DSA, but not for others like RSA.
randfunc : callable
Random number generation function; it should accept a single integer
N and return a string of random data, N bytes long.
If not specified, a new RNG will be instantiated
from ``Cryptodome.Random``.
:Return:
The PKCS#8-wrapped private key (possibly encrypted),
as a binary string.
"""
if key_params is None:
key_params = DerNull()
#
# PrivateKeyInfo ::= SEQUENCE {
# version Version,
# privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
# privateKey PrivateKey,
# attributes [0] IMPLICIT Attributes OPTIONAL
# }
#
pk_info = DerSequence([
0,
DerSequence([
DerObjectId(key_oid),
key_params
]),
DerOctetString(private_key)
])
pk_info_der = pk_info.encode()
if passphrase is None:
return pk_info_der
if not passphrase:
raise ValueError("Empty passphrase")
# Encryption with PBES2
passphrase = tobytes(passphrase)
if protection is None:
protection = 'PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC'
return PBES2.encrypt(pk_info_der, passphrase,
protection, prot_params, randfunc)
def testInit1(self):
der = DerSequence([1, DerInteger(2), b('0\x00')])
self.assertEquals(der.encode(), b('0\x08\x02\x01\x01\x02\x01\x020\x00'))
def testInit1(self):
der = DerSequence([1, DerInteger(2), b('0\x00')])
self.assertEquals(der.encode(),
b('0\x08\x02\x01\x01\x02\x01\x020\x00'))
def testEncode3(self):
# One multi-byte integer (non-zero)
der = DerSequence()
der.append(0x180L)
self.assertEquals(der.encode(), b('0\x04\x02\x02\x01\x80'))
def testEncode5(self):
der = DerSequence()
der += 1
der += b('\x30\x00')
self.assertEquals(der.encode(), b('\x30\x05\x02\x01\x01\x30\x00'))
