Rewrite PHP Rijndael algorithm to Java (Android)

Question

I need to encode a string in Java and php where the result must be the same.

The following conditions are given:

1. algorithm: RIJNDAEL-128
2. key:

Answer 1

Looks like your PHP version uses AES-128, which by definition, uses 128-bit (16-byte) keys. However looks like you passed in a 25-byte key (5P443m2Q1R9A7f5r3e1z08642), which I'm not sure what PHP does when that happens.

Your Java version's getKeyBytes() method only returns the first 16 bytes of the supplied key, so it encrypts with only that.

Try truncating the key in your PHP version to 5P443m2Q1R9A7f5r and you'd get the same result. Except the end part which may be different. At that point, the issue then would be the padding. You can apply the pkcs5_pad PHP function on your plaintext so it matches your Java version.

All that said, if this was just for learning purposes, it's ok. Otherwise, for actual use it's important that you do not use ECB cipher mode.