Support or masked 34.10 keys

[pygost.git] / pygost / gost3410_vko.py

diff --git a/pygost/gost3410_vko.py b/pygost/gost3410_vko.py
index 1c886080a2b86691a19b5452a29785194f7aae6b..3f169dc106df8fba40d46cc5fb198e9dc4e23152 100644 (file)
--- 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) 2015-2021 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
@@ -32,11 +32,13 @@ def ukm_unmarshal(ukm):
     return bytes2long(ukm[::-1])
 
 
-def kek(curve, prv, pub, ukm):
+def kek(curve, prv, pub, ukm, mask=None):
     if not curve.contains(pub):
         raise ValueError("pub is not on the curve")
     key = curve.exp(prv, pub[0], pub[1])
     key = curve.exp(curve.cofactor * ukm, key[0], key[1])
+    if mask is not None:
+        key = curve.exp(mask, key[0], key[1])
     return pub_marshal(key)