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"""M2Crypto wrapper for OpenSSL RSA API.
Copyright (c) 1999-2004 Ng Pheng Siong. All rights reserved."""
import sys
import util, BIO, Err, m2
class RSAError(Exception): pass
m2.rsa_init(RSAError)
no_padding = m2.no_padding
pkcs1_padding = m2.pkcs1_padding
sslv23_padding = m2.sslv23_padding
pkcs1_oaep_padding = m2.pkcs1_oaep_padding
class RSA:
"""
RSA Key Pair.
"""
m2_rsa_free = m2.rsa_free
def __init__(self, rsa, _pyfree=0):
assert m2.rsa_type_check(rsa), "'rsa' type error"
self.rsa = rsa
self._pyfree = _pyfree
def __del__(self):
if getattr(self, '_pyfree', 0):
self.m2_rsa_free(self.rsa)
def __len__(self):
return m2.rsa_size(self.rsa) << 3
def __getattr__(self, name):
if name == 'e':
return m2.rsa_get_e(self.rsa)
elif name == 'n':
return m2.rsa_get_n(self.rsa)
else:
raise AttributeError
def pub(self):
assert self.check_key(), 'key is not initialised'
return m2.rsa_get_e(self.rsa), m2.rsa_get_n(self.rsa)
def public_encrypt(self, data, padding):
assert self.check_key(), 'key is not initialised'
return m2.rsa_public_encrypt(self.rsa, data, padding)
def public_decrypt(self, data, padding):
assert self.check_key(), 'key is not initialised'
return m2.rsa_public_decrypt(self.rsa, data, padding)
def private_encrypt(self, data, padding):
assert self.check_key(), 'key is not initialised'
return m2.rsa_private_encrypt(self.rsa, data, padding)
def private_decrypt(self, data, padding):
assert self.check_key(), 'key is not initialised'
return m2.rsa_private_decrypt(self.rsa, data, padding)
def save_key_bio(self, bio, cipher='aes_128_cbc', callback=util.passphrase_callback):
"""
Save the key pair to an M2Crypto.BIO.BIO object in PEM format.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object to save key to.
@type cipher: string
@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.
@type callback: Python callable
@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)
def save_key(self, file, cipher='aes_128_cbc', callback=util.passphrase_callback):
"""
Save the key pair to a file in PEM format.
@type file: string
@param file: Name of file to save key to.
@type cipher: string
@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.
@type callback: Python callable
@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.
"""
bio = BIO.openfile(file, 'wb')
return self.save_key_bio(bio, cipher, callback)
save_pem = save_key
def as_pem(self, cipher='aes_128_cbc', callback=util.passphrase_callback):
"""
Returns the key(pair) as a string in PEM format.
"""
bio = BIO.MemoryBuffer()
self.save_key_bio(bio, cipher, callback)
return bio.read()
def save_key_der_bio(self, bio):
"""
Save the key pair to an M2Crypto.BIO.BIO object in DER format.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object to save key to.
"""
return m2.rsa_write_key_der(self.rsa, bio._ptr())
def save_key_der(self, file):
"""
Save the key pair to a file in DER format.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object to save key to.
"""
bio = BIO.openfile(file, 'wb')
return self.save_key_der_bio(bio)
def save_pub_key_bio(self, bio):
"""
Save the public key to an M2Crypto.BIO.BIO object in PEM format.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object to save key to.
"""
return m2.rsa_write_pub_key(self.rsa, bio._ptr())
def save_pub_key(self, file):
"""
Save the public key to a file in PEM format.
@type file: string
@param file: Name of file to save key to.
"""
bio = BIO.openfile(file, 'wb')
return m2.rsa_write_pub_key(self.rsa, bio._ptr())
def check_key(self):
return m2.rsa_check_key(self.rsa)
def sign(self, digest, algo='sha1'):
"""
Signs a digest with the private key
@type digest: str
@param digest: A digest created by using the digest method
@type algo: str
@param algo: The method that created the digest.
Legal values are '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)
def verify(self, data, signature, algo='sha1'):
"""
Verifies the signature with the public key
@type data: str
@param data: Data that has been signed
@type signature: str
@param signature: The signature signed with the private key
@type algo: str
@param algo: The method use to create digest from the data
before it was signed. Legal values are 'sha1','sha224',
'sha256', 'ripemd160', and 'md5'.
@returns True or False, depending on whether the signature was
verified.
"""
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)
class RSA_pub(RSA):
"""
Object interface to an RSA public key.
"""
def __setattr__(self, name, value):
if name in ['e', 'n']:
raise RSAError, \
'use factory function new_pub_key() to set (e, n)'
else:
self.__dict__[name] = value
def private_encrypt(self, *argv):
raise RSAError, 'RSA_pub object has no private key'
def private_decrypt(self, *argv):
raise RSAError, 'RSA_pub object has no private key'
save_key = RSA.save_pub_key
save_key_bio = RSA.save_pub_key_bio
#save_key_der = RSA.save_pub_key_der
#save_key_der_bio = RSA.save_pub_key_der_bio
def check_key(self):
return m2.rsa_check_pub_key(self.rsa)
def rsa_error():
raise RSAError, m2.err_reason_error_string(m2.err_get_error())
def keygen_callback(p, n, out=sys.stdout):
"""
Default callback for gen_key().
"""
ch = ['.','+','*','\n']
out.write(ch[p])
out.flush()
def gen_key(bits, e, callback=keygen_callback):
"""
Generate an RSA key pair.
@type bits: int
@param bits: Key length, in bits.
@type e: int
@param e: The RSA public exponent.
@type callback: Python callable
@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.
@rtype: M2Crypto.RSA.RSA
@return: M2Crypto.RSA.RSA object.
"""
return RSA(m2.rsa_generate_key(bits, e, callback), 1)
def load_key(file, callback=util.passphrase_callback):
"""
Load an RSA key pair from file.
@type file: string
@param file: Name of file containing RSA public key in PEM format.
@type callback: Python callable
@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.
@rtype: M2Crypto.RSA.RSA
@return: M2Crypto.RSA.RSA object.
"""
bio = BIO.openfile(file)
return load_key_bio(bio, callback)
def load_key_bio(bio, callback=util.passphrase_callback):
"""
Load an RSA key pair from an M2Crypto.BIO.BIO object.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object containing RSA key pair in PEM
format.
@type callback: Python callable
@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.
@rtype: M2Crypto.RSA.RSA
@return: M2Crypto.RSA.RSA object.
"""
rsa = m2.rsa_read_key(bio._ptr(), callback)
if rsa is None:
rsa_error()
return RSA(rsa, 1)
def load_key_string(string, callback=util.passphrase_callback):
"""
Load an RSA key pair from a string.
@type string: string
@param string: String containing RSA key pair in PEM format.
@type callback: Python callable
@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.
@rtype: M2Crypto.RSA.RSA
@return: M2Crypto.RSA.RSA object.
"""
bio = BIO.MemoryBuffer(string)
return load_key_bio(bio, callback)
def load_pub_key(file):
"""
Load an RSA public key from file.
@type file: string
@param file: Name of file containing RSA public key in PEM format.
@rtype: M2Crypto.RSA.RSA_pub
@return: M2Crypto.RSA.RSA_pub object.
"""
bio = BIO.openfile(file)
return load_pub_key_bio(bio)
def load_pub_key_bio(bio):
"""
Load an RSA public key from an M2Crypto.BIO.BIO object.
@type bio: M2Crypto.BIO.BIO
@param bio: M2Crypto.BIO.BIO object containing RSA public key in PEM
format.
@rtype: M2Crypto.RSA.RSA_pub
@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)
def new_pub_key((e, n)):
"""
Instantiate an RSA_pub object from an (e, n) tuple.
@type e: string
@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.
@type n: string
@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.
@rtype: M2Crypto.RSA.RSA_pub
@return: M2Crypto.RSA.RSA_pub object.
"""
rsa = m2.rsa_new()
m2.rsa_set_e(rsa, e)
m2.rsa_set_n(rsa, n)
return RSA_pub(rsa, 1)
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