fix(crypto/secp256k1): UnmarshalText (#4419)

Author: RodrigoVillar

utils/crypto/secp256k1/secp256k1.go

@@ -262,11 +262,19 @@ func (k *PrivateKey) UnmarshalJSON(b []byte) error {
 	}
 
 	strNoQuotes := str[1:lastIndex]
-	if !strings.HasPrefix(strNoQuotes, PrivateKeyPrefix) {
+	return k.unmarshalText(strNoQuotes)
+}
+
+func (k *PrivateKey) UnmarshalText(text []byte) error {
+	return k.unmarshalText(string(text))
+}
+
+func (k *PrivateKey) unmarshalText(text string) error {
+	if !strings.HasPrefix(text, PrivateKeyPrefix) {
 		return errMissingKeyPrefix
 	}
 
-	strNoPrefix := strNoQuotes[len(PrivateKeyPrefix):]
+	strNoPrefix := text[len(PrivateKeyPrefix):]
 	keyBytes, err := cb58.Decode(strNoPrefix)
 	if err != nil {
 		return err
@@ -282,10 +290,6 @@ func (k *PrivateKey) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
-func (k *PrivateKey) UnmarshalText(text []byte) error {
-	return k.UnmarshalJSON(text)
-}
-
 // raw sig has format [v || r || s] whereas the sig has format [r || s || v]
 func rawSigToSig(sig []byte) ([]byte, error) {
 	if len(sig) != SignatureLen {

utils/crypto/secp256k1/secp256k1_test.go

@@ -173,6 +173,20 @@ func TestPrivateKeySECP256K1RUnmarshalJSONError(t *testing.T) {
 	}
 }
 
+func TestPrivateKeySECP256K1RUnmarshalText(t *testing.T) {
+	require := require.New(t)
+
+	key, err := NewPrivateKey()
+	require.NoError(err)
+
+	keyText, err := key.MarshalText()
+	require.NoError(err)
+
+	key2 := PrivateKey{}
+	require.NoError(key2.UnmarshalText(keyText))
+	require.Equal(key.PublicKey(), key2.PublicKey())
+}
+
 func TestSigning(t *testing.T) {
 	tests := []struct {
 		msg []byte