Remove excess gost3410.Mode

[gogost.git] / gost3410 / vko2001.go

diff --git a/gost3410/vko2001.go b/gost3410/vko2001.go
index c950280bf7f6de78a5e4ee71e4aab7898488ca22..8559ed2a9c2dc807302a22d0b02fedea1c8b68be 100644 (file)
--- a/gost3410/vko2001.go
+++ b/gost3410/vko2001.go
@@ -1,5 +1,5 @@
 // GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2019 Sergey Matveev <stargrave@stargrave.org>
+// Copyright (C) 2015-2020 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
@@ -26,14 +26,16 @@ import (
 // RFC 4357 VKO GOST R 34.10-2001 key agreement function.
 // UKM is user keying material, also called VKO-factor.
 func (prv *PrivateKey) KEK2001(pub *PublicKey, ukm *big.Int) ([]byte, error) {
-       if prv.Mode != Mode2001 {
-               return nil, errors.New("gogost/gost3410: KEK2001 can not be used in Mode2012")
+       if prv.C.PointSize() != 32 {
+               return nil, errors.New("gogost/gost3410: KEK2001 is only for 256-bit curves")
        }
        key, err := prv.KEK(pub, ukm)
        if err != nil {
                return nil, err
        }
        h := gost341194.New(&gost28147.SboxIdGostR341194CryptoProParamSet)
-       h.Write(key)
+       if _, err = h.Write(key); err != nil {
+               return nil, err
+       }
        return h.Sum(key[:0]), nil
 }