X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=pygost%2Fgost3410_vko.py;h=1c886080a2b86691a19b5452a29785194f7aae6b;hb=9af4461c6af50f9cf83030867e7054d1f6311b32;hp=046df9e1212cfaafe6712cbb7b80f2cd2e1f16d2;hpb=a2b4808f6628225be99874bd5f6a0f80a514db82;p=pygost.git

diff --git a/pygost/gost3410_vko.py b/pygost/gost3410_vko.py
index 046df9e..1c88608 100644
--- a/pygost/gost3410_vko.py
+++ b/pygost/gost3410_vko.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 # PyGOST -- Pure Python GOST cryptographic functions library
-# Copyright (C) 2015-2020 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2015-2021 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
@@ -26,20 +26,22 @@ from pygost.utils import bytes2long
 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
@@ -54,13 +56,13 @@ def kek_34102001(curve, prv, pub, ukm):
     hash output.
     """
     return GOST341194(
-        kek(curve, prv, pub, ukm, mode=2001),
-        "id-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
@@ -73,11 +75,11 @@ def kek_34102012256(curve, prv, pub, ukm=1, mode=2012):
     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
@@ -90,4 +92,4 @@ def kek_34102012512(curve, prv, pub, ukm=1):
     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()