充电桩互联互通 hmac-md5加密算法

HmacMd5Signature

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.Arrays;
public class HmacMd5Signature {
    private static final byte IPAD = 0x36;
    private static final byte OPAD = 0x5C;

    public static String hmacMd5(String data, String sigSecret) throws Exception {
        byte[] keyBytes = sigSecret.getBytes(StandardCharsets.UTF_8);
        byte[] dataBytes = data.getBytes(StandardCharsets.UTF_8);

        byte[] paddedKey = Arrays.copyOf(keyBytes, 64);
        byte[] xorIpad = new byte[64];
        byte[] xorOpad = new byte[64];

        for (int i = 0; i < 64; i++) {
            xorIpad[i] = (byte) (paddedKey[i] ^ IPAD);
            xorOpad[i] = (byte) (paddedKey[i] ^ OPAD);
        }

        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(xorIpad);
        md.update(dataBytes);
        byte[] hashIpad = md.digest();

        byte[] finalData = new byte[64 + hashIpad.length];
        System.arraycopy(xorOpad, 0, finalData, 0, 64);
        System.arraycopy(hashIpad, 0, finalData, 64, hashIpad.length);

        md.reset();
        md.update(finalData);
        byte[] hmacMd5 = md.digest();

        StringBuilder result = new StringBuilder();
        for (byte b : hmacMd5) {
            result.append(String.format("%02x", b));
        }

        return result.toString().toUpperCase();
    }