Unable to exchange data encrypted with AES-256 between Java and PHP

Question

My problem is: what I encrypt in Java I can decrypt perfectly in Java, but PHP mcrypt can\'t decrypt. What I encrypt with mcrypt I can decrypt with

Answer 1

I know this is an old topic, but I will add my working solution.

You have to rewrite PHP side of the script:

function getEncrypt($sStr, $sKey) {
  return base64_encode(
    mcrypt_encrypt(
        MCRYPT_RIJNDAEL_128, 
        base64_decode($sKey),
        $sStr,
        MCRYPT_MODE_ECB
    )
  );
}

function getDecrypt($sStr, $sKey) {
  return mcrypt_decrypt(
    MCRYPT_RIJNDAEL_128, 
    base64_decode($sKey), 
    base64_decode($sStr), 
    MCRYPT_MODE_ECB
  );
}

You should base64_decode($sKey) because your key is base64 encoded.

$key = "Zvzpv8/PXbezPCZpxzQKzL/FeoPw68jIb+NONX/LIi8=";

Then, you need to create this function (credit goes to beltrachi from http://www.php.net/manual/en/function.mcrypt-decrypt.php):

function pkcs5_pad ($text, $blocksize) { 
  $pad = $blocksize - (strlen($text) % $blocksize); 
  return $text . str_repeat(chr($pad), $pad); 
}

Use this code do encode/decode:

$decrypt = getDecrypt("6XremNEs1jv/Nnf/fRlQob6oG1jkge+5Ut3PL489oIo=", $key);
echo $decrypt;
echo "\n\n";
echo getEncrypt(pkcs5_pad("My very secret text:)", 16), $key);

I hope this will be useful for someone! :)