Merge pull request #148 from easyops-cn/cryptobyte

chore: use golang.org/x/crypto/cryptobyte

sm2/sm2.go

@@ -27,13 +27,17 @@ import (
 	"io"
 	"math/big"
 
+	"golang.org/x/crypto/cryptobyte"
+	cbasn1 "golang.org/x/crypto/cryptobyte/asn1"
+
 	"github.com/tjfoc/gmsm/sm3"
 )
 
 var (
 	default_uid = []byte{0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38}
-	C1C3C2=0
-	C1C2C3=1
+
+	C1C3C2 = 0
+	C1C2C3 = 1
 )
 
 type PublicKey struct {
@@ -46,9 +50,6 @@ type PrivateKey struct {
 	D *big.Int
 }
 
-type sm2Signature struct {
-	R, S *big.Int
-}
 type sm2Cipher struct {
 	XCoordinate *big.Int
 	YCoordinate *big.Int
@@ -71,16 +72,28 @@ func (priv *PrivateKey) Sign(random io.Reader, msg []byte, signer crypto.SignerO
 	if err != nil {
 		return nil, err
 	}
-	return asn1.Marshal(sm2Signature{r, s})
-}
-
-func (pub *PublicKey) Verify(msg []byte, sign []byte) bool {
-	var sm2Sign sm2Signature
-	_, err := asn1.Unmarshal(sign, &sm2Sign)
-	if err != nil {
+	var b cryptobyte.Builder
+	b.AddASN1(cbasn1.SEQUENCE, func(b *cryptobyte.Builder) {
+		b.AddASN1BigInt(r)
+		b.AddASN1BigInt(s)
+	})
+	return b.Bytes()
+}
+
+func (pub *PublicKey) Verify(msg []byte, sig []byte) bool {
+	var (
+		r, s  = &big.Int{}, &big.Int{}
+		inner cryptobyte.String
+	)
+	input := cryptobyte.String(sig)
+	if !input.ReadASN1(&inner, cbasn1.SEQUENCE) ||
+		!input.Empty() ||
+		!inner.ReadASN1Integer(r) ||
+		!inner.ReadASN1Integer(s) ||
+		!inner.Empty() {
 		return false
 	}
-	return Sm2Verify(pub, msg, default_uid, sm2Sign.R, sm2Sign.S)
+	return Sm2Verify(pub, msg, default_uid, r, s)
 }
 
 func (pub *PublicKey) Sm3Digest(msg, uid []byte) ([]byte, error) {
@@ -244,7 +257,7 @@ func Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool {
  *  hash
  *  CipherText
  */
-func Encrypt(pub *PublicKey, data []byte, random io.Reader,mode int) ([]byte, error) {
+func Encrypt(pub *PublicKey, data []byte, random io.Reader, mode int) ([]byte, error) {
 	length := len(data)
 	for {
 		c := []byte{}
@@ -287,42 +300,40 @@ func Encrypt(pub *PublicKey, data []byte, random io.Reader,mode int) ([]byte, er
 		for i := 0; i < length; i++ {
 			c[96+i] ^= data[i]
 		}
-		switch mode{
-	
+		switch mode {
+
 		case C1C3C2:
 			return append([]byte{0x04}, c...), nil
 		case C1C2C3:
 			c1 := make([]byte, 64)
-			c2 := make([]byte, len(c) - 96)
+			c2 := make([]byte, len(c)-96)
 			c3 := make([]byte, 32)
-			copy(c1, c[:64])//x1,y1
-			copy(c3, c[64:96])//hash
-			copy(c2, c[96:])//密文
+			copy(c1, c[:64])   //x1,y1
+			copy(c3, c[64:96]) //hash
+			copy(c2, c[96:])   //密文
 			ciphertext := []byte{}
 			ciphertext = append(ciphertext, c1...)
 			ciphertext = append(ciphertext, c2...)
 			ciphertext = append(ciphertext, c3...)
 			return append([]byte{0x04}, ciphertext...), nil
-    	default:
+		default:
 			return append([]byte{0x04}, c...), nil
+		}
 	}
 }
-}
-
 
-
-func Decrypt(priv *PrivateKey, data []byte,mode int) ([]byte, error) {
+func Decrypt(priv *PrivateKey, data []byte, mode int) ([]byte, error) {
 	switch mode {
 	case C1C3C2:
 		data = data[1:]
-	case  C1C2C3:
+	case C1C2C3:
 		data = data[1:]
 		c1 := make([]byte, 64)
-		c2 := make([]byte, len(data) - 96)
+		c2 := make([]byte, len(data)-96)
 		c3 := make([]byte, 32)
-		copy(c1, data[:64])//x1,y1
-		copy(c2, data[64:len(data) - 32])//密文
-		copy(c3, data[len(data) - 32:])//hash
+		copy(c1, data[:64])             //x1,y1
+		copy(c2, data[64:len(data)-32]) //密文
+		copy(c3, data[len(data)-32:])   //hash
 		c := []byte{}
 		c = append(c, c1...)
 		c = append(c, c3...)
@@ -362,8 +373,6 @@ func Decrypt(priv *PrivateKey, data []byte,mode int) ([]byte, error) {
 	return c, nil
 }
 
-
-
 // keyExchange 为SM2密钥交换算法的第二部和第三步复用部分，协商的双方均调用此函数计算共同的字节串
 // klen: 密钥长度
 // ida, idb: 协商双方的标识，ida为密钥协商算法发起方标识，idb为响应方标识
@@ -479,7 +488,7 @@ func zeroByteSlice() []byte {
 sm2加密，返回asn.1编码格式的密文内容
 */
 func EncryptAsn1(pub *PublicKey, data []byte, rand io.Reader) ([]byte, error) {
-	cipher, err := Encrypt(pub, data, rand,C1C3C2)
+	cipher, err := Encrypt(pub, data, rand, C1C3C2)
 	if err != nil {
 		return nil, err
 	}
@@ -494,7 +503,7 @@ func DecryptAsn1(pub *PrivateKey, data []byte) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	return Decrypt(pub, cipher,C1C3C2)
+	return Decrypt(pub, cipher, C1C3C2)
 }
 
 /*
@@ -670,5 +679,5 @@ func getLastBit(a *big.Int) uint {
 
 // crypto.Decrypter
 func (priv *PrivateKey) Decrypt(_ io.Reader, msg []byte, _ crypto.DecrypterOpts) (plaintext []byte, err error) {
-	return Decrypt(priv, msg,C1C3C2)
+	return Decrypt(priv, msg, C1C3C2)
 }

sm2/utils.go

@@ -20,7 +20,7 @@ func Decompress(a []byte) *PublicKey {
 
 	y2 := sm2P256ToBig(&xx3)
 	y := new(big.Int).ModSqrt(y2, sm2P256.P)
-	if getLastBit(y)!= uint(a[0]) {
+	if getLastBit(y) != uint(a[0]) {
 		y.Sub(sm2P256.P, y)
 	}
 	return &PublicKey{
@@ -41,7 +41,9 @@ func Compress(a *PublicKey) []byte {
 	return buf
 }
 
-
+type sm2Signature struct {
+	R, S *big.Int
+}
 
 func SignDigitToSignData(r, s *big.Int) ([]byte, error) {
 	return asn1.Marshal(sm2Signature{r, s})
@@ -56,4 +58,3 @@ func SignDataToSignDigit(sign []byte) (*big.Int, *big.Int, error) {
 	}
 	return sm2Sign.R, sm2Sign.S, nil
 }
-