/*
 *  Copyright 2014-2023 The GmSSL Project. All Rights Reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the License); you may
 *  not use this file except in compliance with the License.
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 */
package org.gmssl;


import java.math.BigInteger;

/**
 * @author yongfeili
 * @email  290836576@qq.com
 * @date 2023/09/07
 * @description Hex uitl
 */
public class HexUtil {

    /**
     * convert byte array to hex string
     * @param btArr
     * @return String
     */
    public static String byteToHex(byte[] btArr) {
        BigInteger bigInteger = new BigInteger(1, btArr);
        return bigInteger.toString(16);
    }

    /**
     * convert hex string to byte array
     * @param hexString
     * @return byte[]
     */
    public static byte[] hexToByte(String hexString) {
        byte[] byteArray = new BigInteger(hexString, 16)
                .toByteArray();
        if (byteArray[0] == 0) {
            byte[] output = new byte[byteArray.length - 1];
            System.arraycopy(
                    byteArray, 1, output,
                    0, output.length);
            return output;
        }
        return byteArray;
    }
}