# coding: utf-8
# PyGOST -- Pure Python GOST cryptographic functions library
-# Copyright (C) 2015-2018 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2015-2023 Sergey Matveev <stargrave@stargrave.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
+# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
def ukm_unmarshal(ukm):
"""Unmarshal UKM value
- :type ukm: bytes
+ :type ukm: little-endian bytes
:rtype: long
"""
return bytes2long(ukm[::-1])
-def kek(curve, prv, pub, ukm, mode):
+def kek(curve, prv, pub, ukm):
+ if not curve.contains(pub):
+ raise ValueError("pub is not on the curve")
key = curve.exp(prv, pub[0], pub[1])
- key = curve.exp(ukm, key[0], key[1])
- return pub_marshal(key, mode)
+ key = curve.exp(curve.cofactor * ukm, key[0], key[1])
+ return pub_marshal(key)
def kek_34102001(curve, prv, pub, ukm):
- """ Key agreement (34.10-2001, 34.11-94)
+ """Key agreement (34.10-2001, 34.11-94)
:param GOST3410Curve curve: curve to use
:param long prv: private key
hash output.
"""
return GOST341194(
- kek(curve, prv, pub, ukm, mode=2001),
- "GostR3411_94_CryptoProParamSet",
+ kek(curve, prv, pub, ukm),
+ sbox="id-GostR3411-94-CryptoProParamSet",
).digest()
-def kek_34102012256(curve, prv, pub, ukm=1, mode=2012):
- """ Key agreement (34.10-2012, 34.11-2012 256 bit)
+def kek_34102012256(curve, prv, pub, ukm=1):
+ """Key agreement (34.10-2012, 34.11-2012 256 bit)
:param GOST3410Curve curve: curve to use
:param long prv: private key
Shared Key Encryption Key computation is based on
:rfc:`7836` VKO GOST R 34.10-2012.
"""
- return GOST34112012256(kek(curve, prv, pub, ukm, mode=mode)).digest()
+ return GOST34112012256(kek(curve, prv, pub, ukm)).digest()
def kek_34102012512(curve, prv, pub, ukm=1):
- """ Key agreement (34.10-2012, 34.11-2012 512 bit)
+ """Key agreement (34.10-2012, 34.11-2012 512 bit)
:param GOST3410Curve curve: curve to use
:param long prv: private key
Shared Key Encryption Key computation is based on
:rfc:`7836` VKO GOST R 34.10-2012.
"""
- return GOST34112012512(kek(curve, prv, pub, ukm, mode=2012)).digest()
+ return GOST34112012512(kek(curve, prv, pub, ukm)).digest()