Creating an MD5 String using Java

MD5 is a simple cryptographic hashing algorithm widely used for various application. In this tutorial im trying to generate MD5 value from a string and then compare it to mysql’s MD5 query result.

This is my java code to generate MD5, im using java’s MessageDigest.

package com.edw.util;

import java.security.MessageDigest;
import org.junit.Test;

/**
 *
 * @author edw
 */
public class MD5Test {

    public MD5Test() {
    }

    public String hexStringFromBytes(byte[] b) {
        char[] hexChars = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        String hex = "";
        int msb;
        int lsb = 0;
        int i;

        for (i = 0; i < b.length; i++) {
            msb = ((int) b[i] & 0x000000FF) / 16;
            lsb = ((int) b[i] & 0x000000FF) % 16;
            hex = hex + hexChars[msb] + hexChars[lsb];
        }
        return hex;
    }

    @Test
    public void testMD5() throws Exception {
        MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
		
		// get md5 for word "PASSWORD"
        digest.update("PASSWORD".getBytes());
        byte[] passwordBytes = digest.digest();

		// result = 319f4d26e3c536b5dd871bb2c52e3178
        System.out.println(hexStringFromBytes(passwordBytes));		
    }
}

compared to mysql’s md5 function

you can see that MD5 strings generated by java and mysql are both the same.
(H)