util.go

// Copyright 2022 storyicon@foxmail.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package sigverify

import (
	"encoding/hex"
)

// HexDecode returns the bytes represented by the hexadecimal string s.
// s may be prefixed with "0x".
func HexDecode(s string) ([]byte, error) {
	if Has0xPrefix(s) {
		s = s[2:]
	}
	if len(s)%2 == 1 {
		s = "0" + s
	}
	return hex.DecodeString(s)
}

// Has0xPrefix validates str begins with '0x' or '0X'.
func Has0xPrefix(str string) bool {
	return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X')
}

// CopyBytes is used to copy slice
func CopyBytes(data []byte) []byte {
	ret := make([]byte, len(data))
	copy(ret, data)
	return ret
}