Description:
------------
mcrypt_decrypt / encrypt changed between 5.4 and 5.6

in 5.6, and contrary to the doc, the second parameter $key needs to be of sizes 16, 24 or 32 supported, the key should be padded with "\0" to match correct sizes.



Test script:
---------------
        $decryptText = mcrypt_decrypt(
            MCRYPT_RIJNDAEL_256,
            '1234567890ABCDEFGHIJKLM',
            $cryptText,
            MCRYPT_MODE_CBC,
            'aworkingvector'
        );


Expected result:
----------------
Dont throw this error 

mcrypt_encrypt(): Key of size 22 not supported by this algorithm. Only keys of sizes 16, 24 or 32 supported

Or fix the documentation