add Remove0xPrefix() (#29)

crypto/key.go

@@ -15,6 +15,8 @@ import (
 	"github.com/ethereum/go-ethereum/crypto/secp256k1"
 	"github.com/iotexproject/iotex-address/address"
 	"github.com/pkg/errors"
+
+	"github.com/iotexproject/go-pkgs/util"
 )
 
 // const
@@ -71,21 +73,9 @@ func GenerateKeySm2() (PrivateKey, error) {
 	return newP256sm2PrvKey()
 }
 
-func has0xPrefix(s string) bool {
-	if len(s) > 1 {
-		if s[0] == '0' && (s[1] == 'x' || s[1] == 'X') {
-			return true
-		}
-	}
-	return false
-}
-
 // HexStringToPublicKey decodes a string to PublicKey
 func HexStringToPublicKey(pubKey string) (PublicKey, error) {
-	if has0xPrefix(pubKey) {
-		pubKey = pubKey[2:]
-	}
-	b, err := hex.DecodeString(pubKey)
+	b, err := hex.DecodeString(util.Remove0xPrefix(pubKey))
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to decode public key %s", pubKey)
 	}
@@ -94,10 +84,7 @@ func HexStringToPublicKey(pubKey string) (PublicKey, error) {
 
 // HexStringToPrivateKey decodes a string to PrivateKey
 func HexStringToPrivateKey(prvKey string) (PrivateKey, error) {
-	if has0xPrefix(prvKey) {
-		prvKey = prvKey[2:]
-	}
-	b, err := hex.DecodeString(prvKey)
+	b, err := hex.DecodeString(util.Remove0xPrefix(prvKey))
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to decode public key %s", prvKey)
 	}

hash/hash.go

@@ -10,6 +10,8 @@ import (
 	"encoding/hex"
 
 	"github.com/ethereum/go-ethereum/crypto"
+
+	"github.com/iotexproject/go-pkgs/util"
 )
 
 var (
@@ -66,7 +68,7 @@ func BytesToHash160(b []byte) Hash160 {
 
 // HexStringToHash256 decodes the hex string, then copy byte slice into hash
 func HexStringToHash256(s string) (Hash256, error) {
-	b, err := hex.DecodeString(s)
+	b, err := hex.DecodeString(util.Remove0xPrefix(s))
 	if err != nil {
 		return ZeroHash256, err
 	}
@@ -75,7 +77,7 @@ func HexStringToHash256(s string) (Hash256, error) {
 
 // HexStringToHash160 decodes the hex string, then copy byte slice into hash
 func HexStringToHash160(s string) (Hash160, error) {
-	b, err := hex.DecodeString(s)
+	b, err := hex.DecodeString(util.Remove0xPrefix(s))
 	if err != nil {
 		return ZeroHash160, err
 	}

hash/hash_test.go

@@ -19,8 +19,8 @@ func TestHash(t *testing.T) {
 		msg  string
 		hash string
 	}{
-		{"", "c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"},
-		{"abc", "4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45"},
+		{"", "0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"},
+		{"abc", "0X4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45"},
 	}
 
 	for _, test := range tests {

util/util.go

@@ -0,0 +1,10 @@
+package util
+
+func Remove0xPrefix(s string) string {
+	if len(s) > 1 {
+		if s[0] == '0' && (s[1] == 'x' || s[1] == 'X') {
+			return s[2:]
+		}
+	}
+	return s
+}