def wrap(private_key,
key_oid,
passphrase=None,
protection=None,
prot_params=None,
key_params=None,
randfunc=None):
if key_params is None:
key_params = DerNull()
pk_info = newDerSequence(0, newDerSequence(DerObjectId(key_oid),
key_params),
newDerOctetString(private_key))
pk_info_der = pk_info.encode()
if not passphrase:
return pk_info_der
else:
passphrase = tobytes(passphrase)
if protection is None:
protection = 'PBKDF2WithHMAC-SHA1AndDES-EDE3-CBC'
return PBES2.encrypt(pk_info_der, passphrase, protection, prot_params,
randfunc)
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 ``Crypto.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)
if passphrase:
passphrase = tobytes(passphrase)
found = False
try:
p8_private_key = PBES1.decrypt(p8_private_key, passphrase)
found = True
except PbesError, 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, 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?)")
#
def unwrap(p8_private_key, passphrase=None):
"""Unwrap a private key from a PKCS#8 blob (clear or encrypted).
:Parameters:
p8_private_key : byte string
The private key wrapped into a PKCS#8 blob, DER encoded.
passphrase : (byte) 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 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 ``Crypto.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 = newDerSequence(
0,
newDerSequence(
DerObjectId(key_oid),
key_params
),
newDerOctetString(private_key)
)
pk_info_der = pk_info.encode()
if not passphrase:
return pk_info_der
# 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)
if passphrase:
passphrase = tobytes(passphrase)
found = False
try:
p8_private_key = PBES1.decrypt(p8_private_key, passphrase)
found = True
except PbesError, 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, 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 = decode_der(DerSequence, p8_private_key)
if len(pk_info) == 2 and not passphrase:
raise ValueError("Not a valid clear PKCS#8 structure "
"(maybe it is encrypted?)")
if not 3 <= len(pk_info) <= 4 or pk_info[0] != 0:
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
def unwrap(p8_private_key, passphrase=None):
"""Unwrap a private key from a PKCS#8 blob (clear or encrypted).
:Parameters:
p8_private_key : byte string
The private key wrapped into a PKCS#8 blob, DER encoded.
passphrase : (byte) 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 = decode_der(DerSequence, p8_private_key)
if len(pk_info) == 2 and not passphrase:
raise ValueError("Not a valid clear PKCS#8 structure "
"(maybe it is encrypted?)")
if not 3 <= len(pk_info) <= 4 or pk_info[0] != 0:
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
#
# AlgorithmIdentifier ::= SEQUENCE {
# algorithm OBJECT IDENTIFIER,
# parameters ANY DEFINED BY algorithm OPTIONAL
# }
#
algo_id = decode_der(DerSequence, pk_info[1])
if not 1 <= len(algo_id) <= 2:
raise ValueError("Not a valid AlgorithmIdentifier SEQUENCE")
algo = decode_der(DerObjectId, algo_id[0]).value
private_key = decode_der(DerOctetString, pk_info[2]).payload
if len(algo_id) == 2 and algo_id[1] != b('\x05\x00'):
params = algo_id[1]
else:
params = None
return (algo, private_key, params)
def unwrap(p8_private_key, passphrase=None):
"""Unwrap a private key from a PKCS#8 blob (clear or encrypted).
:Parameters:
p8_private_key : byte string
The private key wrapped into a PKCS#8 blob, DER encoded.
passphrase : (byte) 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 test6(self):
ct = PBES2.encrypt(self.ref, self.passphrase,
'scryptAndAES256-CBC')
pt = PBES2.decrypt(ct, self.passphrase)
self.assertEqual(self.ref, pt)
def test3(self):
ct = PBES2.encrypt(self.ref, self.passphrase,
'PBKDF2WithHMAC-SHA1AndAES192-CBC')
pt = PBES2.decrypt(ct, self.passphrase)
self.assertEqual(self.ref, pt)
def test6(self):
ct = PBES2.encrypt(self.ref, self.passphrase,
'scryptAndAES256-CBC')
pt = PBES2.decrypt(ct, self.passphrase)
self.assertEqual(self.ref, pt)
def test3(self):
ct = PBES2.encrypt(self.ref, self.passphrase,
'PBKDF2WithHMAC-SHA1AndAES192-CBC')
pt = PBES2.decrypt(ct, self.passphrase)
self.assertEqual(self.ref, pt)
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, 5))
if len(pk_info) == 2 and not passphrase:
raise ValueError("Not a valid clear PKCS#8 structure "
"(maybe it is encrypted?)")
# RFC5208, PKCS#8, version is v1(0)
#
# PrivateKeyInfo ::= SEQUENCE {
# version Version,
# privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
# privateKey PrivateKey,
# attributes [0] IMPLICIT Attributes OPTIONAL
# }
#
# RFC5915, Asymmetric Key Package, version is v2(1)
#
# OneAsymmetricKey ::= SEQUENCE {
# version Version,
# privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
# privateKey PrivateKey,
# attributes [0] Attributes OPTIONAL,
# ...,
# [[2: publicKey [1] PublicKey OPTIONAL ]],
# ...
# }
if pk_info[0] == 0:
if len(pk_info) not in (3, 4):
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
elif pk_info[0] == 1:
if len(pk_info) not in (3, 4, 5):
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
else:
raise ValueError("Not a valid PrivateKeyInfo SEQUENCE")
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]
# PrivateKey ::= OCTET STRING
private_key = DerOctetString().decode(pk_info[2]).payload
# We ignore attributes and (for v2 only) publickey
return (algo_oid, private_key, algo_params)