status-im/status-go

package types

import "encoding/hex"

// 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')
}

// isHexCharacter returns bool of c being a valid hexadecimal.
func isHexCharacter(c byte) bool {
    return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
}

// isHex validates whether each byte is valid hexadecimal string.
func isHex(str string) bool {
    if len(str)%2 != 0 {
        return false
    }
    for _, c := range []byte(str) {
        if !isHexCharacter(c) {
            return false
        }
    }
    return true
}

// Bytes2Hex returns the hexadecimal encoding of d.
func Bytes2Hex(d []byte) string {
    return hex.EncodeToString(d)
}

// Hex2Bytes returns the bytes represented by the hexadecimal string str.
func Hex2Bytes(str string) []byte {
    if has0xPrefix(str) {
        str = str[2:]
    }

    h, _ := hex.DecodeString(str)
    return h
}

// ToHex returns the hex string representation of bytes with 0x prefix.
func ToHex(bytes []byte) string {
    return "0x" + Bytes2Hex(bytes)
}