-# This implementation is based on Python 3.5.2 source code.
-# PyGOST does not register itself in hashlib anyway, so use
-# pbkdf2_hmac directly.
-def pbkdf2_hmac(password, salt, iterations, dklen):
- inner = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
- outer = GOST341194(sbox="GostR3411_94_CryptoProParamSet")
- password = password + b'\x00' * (inner.block_size - len(password))
- inner.update(strxor(password, len(password) * b"\x36"))
- outer.update(strxor(password, len(password) * b"\x5C"))
-
- def prf(msg):
- icpy = inner.copy()
- ocpy = outer.copy()
- icpy.update(msg)
- ocpy.update(icpy.digest())
- return ocpy.digest()
-
- dkey = b''
- loop = 1
- while len(dkey) < dklen:
- prev = prf(salt + long2bytes(loop, 4))
- rkey = bytes2long(prev)
- for _ in xrange(iterations - 1):
- prev = prf(prev)
- rkey ^= bytes2long(prev)
- loop += 1
- dkey += long2bytes(rkey, inner.digest_size)
- return dkey[:dklen]
-
-