def pbkdf2(password, salt=None, i=10000, keylen=64):
"""Key derivation function using SHA256"""
if salt is None:
salt = OpenSSL.rand(8)
p_password = OpenSSL.malloc(password, len(password))
p_salt = OpenSSL.malloc(salt, len(salt))
output = OpenSSL.malloc(0, keylen)
OpenSSL.PKCS5_PBKDF2_HMAC(p_password, len(password), p_salt, len(p_salt),
i, OpenSSL.EVP_sha256(), keylen, output)
return salt, output.raw
def raw_encrypt(
data,
pubkey_x,
pubkey_y,
curve='sect283r1',
ephemcurve=None,
ciphername='aes-256-cbc',
): # pylint: disable=too-many-arguments
"""ECHD encryption, keys supplied in binary data format"""
if ephemcurve is None:
ephemcurve = curve
ephem = ECC(curve=ephemcurve)
key = sha512(ephem.raw_get_ecdh_key(pubkey_x, pubkey_y)).digest()
key_e, key_m = key[:32], key[32:]
pubkey = ephem.get_pubkey()
iv = OpenSSL.rand(OpenSSL.get_cipher(ciphername).get_blocksize())
ctx = Cipher(key_e, iv, 1, ciphername)
ciphertext = iv + pubkey + ctx.ciphering(data)
mac = hmac_sha256(key_m, ciphertext)
return ciphertext + mac
def randomBytes(n):
"""Method randomBytes."""
try:
return os.urandom(n)
except NotImplementedError:
return OpenSSL.rand(n)
def gen_IV(ciphername):
"""Generate random initialization vector"""
cipher = OpenSSL.get_cipher(ciphername)
return OpenSSL.rand(cipher.get_blocksize())
