MySQL MD5 and Java MD5 not equal

Question

The next function in MySQL

MD5( 'secret' ) generates 5ebe2294ecd0e0f08eab7690d2a6ee69

I would like to have a Java function to generate the same output. But

public static String md5( String source ) {
    try {
        MessageDigest md = MessageDigest.getInstance( "MD5" );
        byte[] bytes = md.digest( source.getBytes("UTF-8") );
        return getString( bytes );
    } catch( Exception e )  {
        e.printStackTrace();
        return null;
    }
}

private static String getString( byte[] bytes ) {
    StringBuffer sb = new StringBuffer();
    for( int i=0; i<bytes.length; i++ ) {
        byte b = bytes[ i ];
        sb.append( ( int )( 0x00FF & b ) );
        if( i+1 <bytes.length ) {
            sb.append( "-" );
        }
    }
    return sb.toString();
}

generates

94-190-34-148-236-208-224-240-142-171-118-144-210-166-238-105

Answer 1

Try encoding in base 16. Just to get you started... 94 in base 16 is 5E.

**Edit:**Try changing your getString method:

private static String getString( byte[] bytes ) 
{
  StringBuffer sb = new StringBuffer();
  for( int i=0; i<bytes.length; i++ )     
  {
     byte b = bytes[ i ];
     String hex = Integer.toHexString((int) 0x00FF & b);
     if (hex.length() == 1) 
     {
        sb.append("0");
     }
     sb.append( hex );
  }
  return sb.toString();
}

Answer 2

replace

sb.append( ( int )( 0x00FF & b ) );
if( i+1 <bytes.length ) {
    sb.append( "-" );
}

by

String hex = Integer.toHexString((int) 0x00FF & b);
if (hex.length == 1) sb.append("0");
sb.append( hex );

Answer 3

This can be shortened to a one-liner by using the utility classes from the Apache Commons Codec library (http://commons.apache.org/codec)

String md = org.apache.commons.codec.digest.DigestUtils.md5hex("whatever");

Answer 4

Those two are equal. The Java one appears to be in decimal. Convert it to hexadecimal.

Answer 5

Consider converting your decimal bytes to hexadecimal. For example 94 base 10 is 5e base 16.

Answer 6

That's because the base is different. The MySQL MD5 result is in base-16, while the Java MD5 is in base-10.

I wish I could help you further, but my math stinks. A friend of mine helped me generate a base-10 checksum from a base-16 checksum in PHP, but I've lost the script. Hope you can find your answer based on this.

Answer 7

String password = org.springframework.util.DigestUtils.md5DigestAsHex("password".getBytes())
System.out.println(password)

Answer 8

Look how I do it, the code is self explainable!

Java code:

public static void main(String a[]) throws NoSuchAlgorithmException {
    String passClear = "cleartext";
    MessageDigest md5 = MessageDigest.getInstance("MD5"); // you can change it to SHA1 if needed!
    md5.update(passClear.getBytes(), 0, passClear.length());
    System.out.printf("MD5: %s: %s ", passClear, new BigInteger(1, md5.digest()).toString(16));
}

Output:

MD5: cleartext: 5ab677ec767735cebd67407005786016

Mysql query that produces the same hash:

SELECT md5( 'cleartext' ); 

Output:

md5('cleartext')
5ab677ec767735cebd67407005786016

Answer 9

Rather than reinventing the wheel, try Apache commons codec (http://commons.apache.org/codec/) which will handle the hex encoding for you with Hex.encodeHex(byte[])

private String encodeAsMD5(String password) {
    try {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] bytes = md.digest(password.getBytes());
        return new String(Hex.encodeHex(bytes));
    } 
    catch(Exception e) {
        e.printStackTrace();
        return null;
    }
}

Answer 10

Use the utility classes from the Apache Commons Codec library: http://commons.apache.org/codec/

String password = org.apache.commons.codec.digest.DigestUtils.md5Hex("password");
System.out.println(password);