from __future__ import absolute_import
"""M2Crypto wrapper for OpenSSL RSA API.
Copyright (c) 1999-2004 Ng Pheng Siong. All rights reserved."""
import sys
from M2Crypto import BIO, Err, m2, util
from typing import Any, AnyStr, Callable, IO, Optional, Tuple # noqa
[docs]
class RSAError(Exception):
pass
m2.rsa_init(RSAError)
no_padding = m2.no_padding
pkcs1_padding = m2.pkcs1_padding
if hasattr(m2, 'sslv23_padding'):
sslv23_padding = m2.sslv23_padding
pkcs1_oaep_padding = m2.pkcs1_oaep_padding
[docs]
class RSA(object):
"""
RSA Key Pair.
"""
m2_rsa_free = m2.rsa_free
def __init__(self, rsa, _pyfree=0):
# type: (bytes, int) -> None
"""
:param rsa: binary representation of OpenSSL RSA type
"""
assert m2.rsa_type_check(rsa), "'rsa' type error"
self.rsa = rsa
self._pyfree = _pyfree
def __del__(self):
# type: () -> None
if getattr(self, '_pyfree', 0):
self.m2_rsa_free(self.rsa)
def __len__(self):
# type: () -> int
return int(m2.rsa_size(self.rsa) << 3)
def __getattr__(self, name):
# type: (str) -> bytes
if name == 'e':
return m2.rsa_get_e(self.rsa)
elif name == 'n':
return m2.rsa_get_n(self.rsa)
else:
raise AttributeError
[docs]
def pub(self):
# type: () -> Tuple[bytes, bytes]
assert self.check_key(), 'key is not initialised'
return m2.rsa_get_e(self.rsa), m2.rsa_get_n(self.rsa)
[docs]
def public_encrypt(self, data, padding):
# type: (bytes, int) -> bytes
assert self.check_key(), 'key is not initialised'
return m2.rsa_public_encrypt(self.rsa, data, padding)
[docs]
def public_decrypt(self, data, padding):
# type: (bytes, int) -> bytes
assert self.check_key(), 'key is not initialised'
return m2.rsa_public_decrypt(self.rsa, data, padding)
[docs]
def private_encrypt(self, data, padding):
# type: (bytes, int) -> bytes
assert self.check_key(), 'key is not initialised'
return m2.rsa_private_encrypt(self.rsa, data, padding)
[docs]
def private_decrypt(self, data, padding):
# type: (bytes, int) -> bytes
assert self.check_key(), 'key is not initialised'
return m2.rsa_private_decrypt(self.rsa, data, padding)
[docs]
def save_key_bio(self, bio, cipher='aes_128_cbc',
callback=util.passphrase_callback):
# type: (BIO.BIO, Optional[str], Callable) -> int
"""
Save the key pair to an M2Crypto.BIO.BIO object in PEM format.
:param bio: M2Crypto.BIO.BIO object to save key to.
:param cipher: Symmetric cipher to protect the key. The default
cipher is 'aes_128_cbc'. If cipher is None, then
the key is saved in the clear.
:param callback: A Python callable object that is invoked
to acquire a passphrase with which to protect
the key. The default is
util.passphrase_callback.
"""
if cipher is None:
return m2.rsa_write_key_no_cipher(self.rsa, bio._ptr(), callback)
else:
ciph = getattr(m2, cipher, None)
if ciph is None:
raise RSAError('not such cipher %s' % cipher)
else:
ciph = ciph()
return m2.rsa_write_key(self.rsa, bio._ptr(), ciph, callback)
[docs]
def save_key(self, file, cipher='aes_128_cbc',
callback=util.passphrase_callback):
# type: (AnyStr, Optional[str], Callable) -> int
"""
Save the key pair to a file in PEM format.
:param file: Name of file to save key to.
:param cipher: Symmetric cipher to protect the key. The default
cipher is 'aes_128_cbc'. If cipher is None, then
the key is saved in the clear.
:param callback: A Python callable object that is invoked
to acquire a passphrase with which to protect
the key. The default is
util.passphrase_callback.
"""
with BIO.openfile(file, 'wb') as bio:
return self.save_key_bio(bio, cipher, callback)
save_pem = save_key
[docs]
def as_pem(self, cipher='aes_128_cbc', callback=util.passphrase_callback):
# type: (Optional[str], Callable) -> bytes
"""
Returns the key(pair) as a string in PEM format.
"""
bio = BIO.MemoryBuffer()
self.save_key_bio(bio, cipher, callback)
return bio.read()
[docs]
def save_key_der_bio(self, bio):
# type: (BIO.BIO) -> int
"""
Save the key pair to an M2Crypto.BIO.BIO object in DER format.
:param bio: M2Crypto.BIO.BIO object to save key to.
"""
return m2.rsa_write_key_der(self.rsa, bio._ptr())
[docs]
def save_key_der(self, file):
# type: (AnyStr) -> int
"""
Save the key pair to a file in DER format.
:param file: Filename to save key to
"""
with BIO.openfile(file, 'wb') as bio:
return self.save_key_der_bio(bio)
[docs]
def save_pub_key_bio(self, bio):
# type: (BIO.BIO) -> int
"""
Save the public key to an M2Crypto.BIO.BIO object in PEM format.
:param bio: M2Crypto.BIO.BIO object to save key to.
"""
return m2.rsa_write_pub_key(self.rsa, bio._ptr())
[docs]
def save_pub_key(self, file):
# type: (AnyStr) -> int
"""
Save the public key to a file in PEM format.
:param file: Name of file to save key to.
"""
with BIO.openfile(file, 'wb') as bio:
return m2.rsa_write_pub_key(self.rsa, bio._ptr())
[docs]
def check_key(self):
# type: () -> int
"""
Validate RSA keys.
It checks that p and q are in fact prime, and that n = p*q.
:return: returns 1 if rsa is a valid RSA key, and 0 otherwise.
-1 is returned if an error occurs while checking the key.
If the key is invalid or an error occurred, the reason
code can be obtained using ERR_get_error(3).
"""
return m2.rsa_check_key(self.rsa)
[docs]
def sign_rsassa_pss(self, digest, algo='sha1', salt_length=20):
# type: (bytes, str, int) -> bytes
"""
Signs a digest with the private key using RSASSA-PSS
:param digest: A digest created by using the digest method
:param salt_length: The length of the salt to use
:param algo: The hash algorithm to use
Legal values like 'sha1','sha224', 'sha256',
'ripemd160', and 'md5'.
:return: a string which is the signature
"""
hash = getattr(m2, algo, None)
if hash is None:
raise RSAError('not such hash algorithm %s' % algo)
signature = m2.rsa_padding_add_pkcs1_pss(self.rsa, digest, hash(), salt_length)
return self.private_encrypt(signature, m2.no_padding)
[docs]
def verify_rsassa_pss(self, data, signature, algo='sha1', salt_length=20):
# type: (bytes, bytes, str, int) -> int
"""
Verifies the signature RSASSA-PSS
:param data: Data that has been signed
:param signature: The signature signed with RSASSA-PSS
:param salt_length: The length of the salt that was used
:param algo: The hash algorithm to use
Legal values are for example 'sha1','sha224',
'sha256', 'ripemd160', and 'md5'.
:return: 1 or 0, depending on whether the signature was
verified or not.
"""
hash = getattr(m2, algo, None)
if hash is None:
raise RSAError('not such hash algorithm %s' % algo)
plain_signature = self.public_decrypt(signature, m2.no_padding)
return m2.rsa_verify_pkcs1_pss(self.rsa, data, plain_signature, hash(), salt_length)
[docs]
def sign(self, digest, algo='sha1'):
# type: (bytes, str) -> bytes
"""
Signs a digest with the private key
:param digest: A digest created by using the digest method
:param algo: The method that created the digest.
Legal values like 'sha1','sha224', 'sha256',
'ripemd160', and 'md5'.
:return: a string which is the signature
"""
digest_type = getattr(m2, 'NID_' + algo, None)
if digest_type is None:
raise ValueError('unknown algorithm', algo)
return m2.rsa_sign(self.rsa, digest, digest_type)
[docs]
def verify(self, data, signature, algo='sha1'):
# type: (bytes, bytes, str) -> int
"""
Verifies the signature with the public key
:param data: Data that has been signed
:param signature: The signature signed with the private key
:param algo: The method use to create digest from the data
before it was signed. Legal values like
'sha1','sha224', 'sha256', 'ripemd160', and 'md5'.
:return: 1 or 0, depending on whether the signature was
verified or not.
"""
digest_type = getattr(m2, 'NID_' + algo, None)
if digest_type is None:
raise ValueError('unknown algorithm', algo)
return m2.rsa_verify(self.rsa, data, signature, digest_type)
[docs]
class RSA_pub(RSA):
"""
Object interface to an RSA public key.
"""
def __setattr__(self, name, value):
# type: (str, bytes) -> None
if name in ['e', 'n']:
raise RSAError('use factory function new_pub_key() to set (e, n)')
else:
self.__dict__[name] = value
[docs]
def private_encrypt(self, *argv):
# type: (*Any) -> None
raise RSAError('RSA_pub object has no private key')
[docs]
def private_decrypt(self, *argv):
# type: (*Any) -> None
raise RSAError('RSA_pub object has no private key')
[docs]
def save_key(self, file, *args, **kw):
# type: (AnyStr, *Any, **Any) -> int
"""
Save public key to file.
"""
return self.save_pub_key(file)
[docs]
def save_key_bio(self, bio, *args, **kw):
# type: (BIO.BIO, *Any, **Any) -> int
"""
Save public key to BIO.
"""
return self.save_pub_key_bio(bio)
# save_key_der
# save_key_der_bio
[docs]
def check_key(self):
# type: () -> int
return m2.rsa_check_pub_key(self.rsa)
[docs]
def rsa_error():
# type: () -> None
raise RSAError(Err.get_error_message())
[docs]
def keygen_callback(p, n, out=sys.stdout):
# type: (int, Any, IO[str]) -> None
"""
Default callback for gen_key().
"""
ch = ['.', '+', '*', '\n']
out.write(ch[p])
out.flush()
[docs]
def gen_key(bits, e, callback=keygen_callback):
# type: (int, int, Callable) -> RSA
"""
Generate an RSA key pair.
:param bits: Key length, in bits.
:param e: The RSA public exponent.
:param callback: A Python callable object that is invoked
during key generation; its usual purpose is to
provide visual feedback. The default callback is
keygen_callback.
:return: M2Crypto.RSA.RSA object.
"""
return RSA(m2.rsa_generate_key(bits, e, callback), 1)
[docs]
def load_key(file, callback=util.passphrase_callback):
# type: (AnyStr, Callable) -> RSA
"""
Load an RSA key pair from file.
:param file: Name of file containing RSA public key in PEM format.
:param callback: A Python callable object that is invoked
to acquire a passphrase with which to unlock the
key. The default is util.passphrase_callback.
:return: M2Crypto.RSA.RSA object.
"""
with BIO.openfile(file) as bio:
return load_key_bio(bio, callback)
[docs]
def load_key_bio(bio, callback=util.passphrase_callback):
# type: (BIO.BIO, Callable) -> RSA
"""
Load an RSA key pair from an M2Crypto.BIO.BIO object.
:param bio: M2Crypto.BIO.BIO object containing RSA key pair in PEM
format.
:param callback: A Python callable object that is invoked
to acquire a passphrase with which to unlock the
key. The default is util.passphrase_callback.
:return: M2Crypto.RSA.RSA object.
"""
rsa = m2.rsa_read_key(bio._ptr(), callback)
if rsa is None:
rsa_error()
return RSA(rsa, 1)
[docs]
def load_key_string(string, callback=util.passphrase_callback):
# type: (AnyStr, Callable) -> RSA
"""
Load an RSA key pair from a string.
:param string: String containing RSA key pair in PEM format.
:param callback: A Python callable object that is invoked
to acquire a passphrase with which to unlock the
key. The default is util.passphrase_callback.
:return: M2Crypto.RSA.RSA object.
"""
bio = BIO.MemoryBuffer(string)
return load_key_bio(bio, callback)
[docs]
def load_pub_key(file):
# type: (AnyStr) -> RSA_pub
"""
Load an RSA public key from file.
:param file: Name of file containing RSA public key in PEM format.
:return: M2Crypto.RSA.RSA_pub object.
"""
with BIO.openfile(file) as bio:
return load_pub_key_bio(bio)
[docs]
def load_pub_key_bio(bio):
# type: (BIO.BIO) -> RSA_pub
"""
Load an RSA public key from an M2Crypto.BIO.BIO object.
:param bio: M2Crypto.BIO.BIO object containing RSA public key in PEM
format.
:return: M2Crypto.RSA.RSA_pub object.
"""
rsa = m2.rsa_read_pub_key(bio._ptr())
if rsa is None:
rsa_error()
return RSA_pub(rsa, 1)
[docs]
def new_pub_key(e_n):
# type: (Tuple[bytes, bytes]) -> RSA_pub
"""
Instantiate an RSA_pub object from an (e, n) tuple.
:param e: The RSA public exponent; it is a string in OpenSSL's MPINT
format - 4-byte big-endian bit-count followed by the
appropriate number of bits.
:param n: The RSA composite of primes; it is a string in OpenSSL's
MPINT format - 4-byte big-endian bit-count followed by the
appropriate number of bits.
:return: M2Crypto.RSA.RSA_pub object.
"""
(e, n) = e_n
rsa = m2.rsa_new()
m2.rsa_set_en(rsa, e, n)
return RSA_pub(rsa, 1)