+++ /dev/null
-// GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2019 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
-// the Free Software Foundation, version 3 of the License.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-package gost3410
-
-import (
- "crypto"
- "errors"
- "io"
- "math/big"
-)
-
-type PrivateKey struct {
- C *Curve
- Mode Mode
- Key *big.Int
-}
-
-func NewPrivateKey(curve *Curve, mode Mode, raw []byte) (*PrivateKey, error) {
- if len(raw) != int(mode) {
- return nil, errors.New("Invalid private key length")
- }
- key := make([]byte, int(mode))
- for i := 0; i < len(key); i++ {
- key[i] = raw[len(raw)-i-1]
- }
- k := bytes2big(key)
- if k.Cmp(zero) == 0 {
- return nil, errors.New("Zero private key")
- }
- return &PrivateKey{curve, mode, k}, nil
-}
-
-func GenPrivateKey(curve *Curve, mode Mode, rand io.Reader) (*PrivateKey, error) {
- raw := make([]byte, int(mode))
- if _, err := io.ReadFull(rand, raw); err != nil {
- return nil, err
- }
- return NewPrivateKey(curve, mode, raw)
-}
-
-func (prv *PrivateKey) Raw() []byte {
- raw := pad(prv.Key.Bytes(), int(prv.Mode))
- reverse(raw)
- return raw
-}
-
-func (prv *PrivateKey) PublicKey() (*PublicKey, error) {
- x, y, err := prv.C.Exp(prv.Key, prv.C.X, prv.C.Y)
- if err != nil {
- return nil, err
- }
- return &PublicKey{prv.C, prv.Mode, x, y}, nil
-}
-
-func (prv *PrivateKey) SignDigest(digest []byte, rand io.Reader) ([]byte, error) {
- e := bytes2big(digest)
- e.Mod(e, prv.C.Q)
- if e.Cmp(zero) == 0 {
- e = big.NewInt(1)
- }
- kRaw := make([]byte, int(prv.Mode))
- var err error
- var k *big.Int
- var r *big.Int
- d := big.NewInt(0)
- s := big.NewInt(0)
-Retry:
- if _, err = io.ReadFull(rand, kRaw); err != nil {
- return nil, err
- }
- k = bytes2big(kRaw)
- k.Mod(k, prv.C.Q)
- if k.Cmp(zero) == 0 {
- goto Retry
- }
- r, _, err = prv.C.Exp(k, prv.C.X, prv.C.Y)
- if err != nil {
- return nil, err
- }
- r.Mod(r, prv.C.Q)
- if r.Cmp(zero) == 0 {
- goto Retry
- }
- d.Mul(prv.Key, r)
- k.Mul(k, e)
- s.Add(d, k)
- s.Mod(s, prv.C.Q)
- if s.Cmp(zero) == 0 {
- goto Retry
- }
- return append(
- pad(s.Bytes(), int(prv.Mode)),
- pad(r.Bytes(), int(prv.Mode))...,
- ), nil
-}
-
-func (prv *PrivateKey) Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
- return prv.SignDigest(digest, rand)
-}
-
-func (prv *PrivateKey) Public() crypto.PublicKey {
- pub, err := prv.PublicKey()
- if err != nil {
- panic(err)
- }
- return pub
-}