Forbid any later GNU GPL versions autousage

[gogost.git] / src / cypherpunks.ru / gogost / gost3410 / private.go

diff --git a/src/cypherpunks.ru/gogost/gost3410/private.go b/src/cypherpunks.ru/gogost/gost3410/private.go
index a1cba81580726cfd2df92fc8cf4518b499af050e..045c8185b94458e7ad2c9be153bd37eeb99f04ed 100644 (file)
--- a/src/cypherpunks.ru/gogost/gost3410/private.go
+++ b/src/cypherpunks.ru/gogost/gost3410/private.go
@@ -1,10 +1,9 @@
 // GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2017 Sergey Matveev <stargrave@stargrave.org>
+// 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, either version 3 of the License, or
-// (at your option) any later version.
+// 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
@@ -17,24 +16,26 @@
 package gost3410
 
 import (
+       "crypto"
        "errors"
        "io"
        "math/big"
 )
 
 type PrivateKey struct {
-       c    *Curve
-       mode Mode
-       key  *big.Int
+       C    *Curve
+       Mode Mode
+       Key  *big.Int
 }
 
 func NewPrivateKey(curve *Curve, mode Mode, raw []byte) (*PrivateKey, error) {
        if len(raw) != int(mode) {
-               errors.New("Invalid private key length")
+               return nil, errors.New("Invalid private key length")
        }
        key := make([]byte, int(mode))
-       copy(key, raw)
-       reverse(key)
+       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")
@@ -51,26 +52,26 @@ func GenPrivateKey(curve *Curve, mode Mode, rand io.Reader) (*PrivateKey, error)
 }
 
 func (prv *PrivateKey) Raw() []byte {
-       raw := pad(prv.key.Bytes(), int(prv.mode))
+       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.Bx, prv.c.By)
+       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
+       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)
+       e.Mod(e, prv.C.Q)
        if e.Cmp(zero) == 0 {
                e = big.NewInt(1)
        }
-       kRaw := make([]byte, int(prv.mode))
+       kRaw := make([]byte, int(prv.Mode))
        var err error
        var k *big.Int
        var r *big.Int
@@ -81,27 +82,39 @@ Retry:
                return nil, err
        }
        k = bytes2big(kRaw)
-       k.Mod(k, prv.c.Q)
+       k.Mod(k, prv.C.Q)
        if k.Cmp(zero) == 0 {
                goto Retry
        }
-       r, _, err = prv.c.Exp(k, prv.c.Bx, prv.c.By)
+       r, _, err = prv.C.Exp(k, prv.C.X, prv.C.Y)
        if err != nil {
                return nil, err
        }
-       r.Mod(r, prv.c.Q)
+       r.Mod(r, prv.C.Q)
        if r.Cmp(zero) == 0 {
                goto Retry
        }
-       d.Mul(prv.key, r)
+       d.Mul(prv.Key, r)
        k.Mul(k, e)
        s.Add(d, k)
-       s.Mod(s, prv.c.Q)
+       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))...,
+               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
+}