1 // GoGOST -- Pure Go GOST cryptographic functions library
2 // Copyright (C) 2015-2023 Sergey Matveev <stargrave@stargrave.org>
4 // This program is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, version 3 of the License.
8 // This program is distributed in the hope that it will be useful,
9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 // GNU General Public License for more details.
13 // You should have received a copy of the GNU General Public License
14 // along with this program. If not, see <http://www.gnu.org/licenses/>.
22 "go.cypherpunks.ru/gogost/v5/gost34112012256"
23 "go.cypherpunks.ru/gogost/v5/gost34112012512"
26 // RFC 7836 VKO GOST R 34.10-2012 256-bit key agreement function.
27 // UKM is user keying material, also called VKO-factor.
28 func (prv *PrivateKey) KEK2012256(pub *PublicKey, ukm *big.Int) ([]byte, error) {
29 key, err := prv.KEK(pub, ukm)
31 return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK2012256: %w", err)
33 h := gost34112012256.New()
34 if _, err = h.Write(key); err != nil {
35 return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK2012256: %w", err)
37 return h.Sum(key[:0]), nil
40 // RFC 7836 VKO GOST R 34.10-2012 512-bit key agreement function.
41 // UKM is user keying material, also called VKO-factor.
42 func (prv *PrivateKey) KEK2012512(pub *PublicKey, ukm *big.Int) ([]byte, error) {
43 key, err := prv.KEK(pub, ukm)
45 return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK2012256: %w", err)
47 h := gost34112012512.New()
48 if _, err = h.Write(key); err != nil {
49 return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK2012256: %w", err)
51 return h.Sum(key[:0]), nil