1 // GoGOST -- Pure Go GOST cryptographic functions library
2 // Copyright (C) 2015-2019 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, either version 3 of the License, or
7 // (at your option) any later version.
9 // This program is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with this program. If not, see <http://www.gnu.org/licenses/>.
19 func (mgm *MGM) mul(xBuf, yBuf []byte) []byte {
24 for mgm.y.BitLen() != 0 {
25 if mgm.y.Bit(0) == 1 {
26 mgm.z.Xor(mgm.z, mgm.x)
28 if mgm.x.Bit(mgm.maxBit) == 1 {
29 mgm.x.SetBit(mgm.x, mgm.maxBit, 0)
31 mgm.x.Xor(mgm.x, mgm.r)
37 zBytes := mgm.z.Bytes()
38 rem := len(xBuf) - len(zBytes)
39 for i = 0; i < rem; i++ {
42 copy(mgm.mulBuf[rem:], zBytes)