Implementing this Java password encryption algorithm in PHP

Question

Hey,

I'm trying to implement a password encryption algorithm used in Funambol mobile sync server in PHP but I'm having hard time as I come from a non-Java background. The code itself seems simple:

encryptionKey   = "Omnia Gallia in tres partes divida est";
byte[] newValue = new byte[24];
System.arraycopy(encryptionKey, 0, newValue, 0, 24);
encryptionKey   = newValue;

KeySpec keySpec             = new DESedeKeySpec(encryptionKey);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESEde");
Cipher cipher               = Cipher.getInstance("DESEde");    
SecretKey key               = keyFactory.generateSecret(keySpec);

cipher.init(Cipher.ENCRYPT_MODE, key);

cipherBytes = cipher.doFinal(plainBytes);

I'm not necessarily looking for a complete solution, rather pointers on what I can use on PHP's side. Can mcrypt handle this and to what extent? What else do I need? Is this even doable in PHP?

To the curious: I'm building an interface to the Funambol server and I'd like to be able to add users from the interface itself using PHP.

Answer 1

This may be what you want:

$td = mcrypt_module_open('tripledes', '', 'ecb', '');
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
$nKeySize = mcrypt_enc_get_key_size($td);

$key = substr(sha1($encryptionKey), 0, $nKeySize);
mcrypt_generic_init($td, $key, $iv);
$nDataSize = strlen($plainBytes);
$sDataSize = substr(dechex(ceil(log($nDataSize,16))), -1) . dechex($nDataSize);

$cipherBytes = mcrypt_generic($td, $sDataSize . $plainBytes);

mcrypt_generic_deinit($td);
mcrypt_module_close($td);

Notice I encrypt $sDataSize with the data because of the way 3DES encypts/decrypts blocks of data.

Answer 2

Finally got it solved, posting here in case someone ever needs to encrypt or decrypt passwords for Funambol using PHP:

class Funambol_auth {

    private static $key = "Omnia Gallia in tres par";

    public static function encrypt($data) {
        $size = mcrypt_get_block_size('des', 'ecb');
        $data = self::pkcs5_pad($data, $size);
        $mcrypt_module = mcrypt_module_open(MCRYPT_TRIPLEDES, '', 'ecb', '');
        $mcrypt_iv     = mcrypt_create_iv(mcrypt_enc_get_iv_size($mcrypt_module), MCRYPT_RAND);
        $key_size      = mcrypt_enc_get_key_size($mcrypt_module);

        mcrypt_generic_init($mcrypt_module,self::$key,$mcrypt_iv);
        $encrypted = base64_encode(mcrypt_generic($mcrypt_module, $data));
        mcrypt_module_close($mcrypt_module);

        return $encrypted;
    }

    public static function decrypt($data) {
        $mcrypt_module = mcrypt_module_open(MCRYPT_TRIPLEDES, '', 'ecb', '');
        $mcrypt_iv     = mcrypt_create_iv(mcrypt_enc_get_iv_size($mcrypt_module), MCRYPT_RAND);
        $decrypted     = mcrypt_decrypt(MCRYPT_TRIPLEDES, self::$key, base64_decode($data), 'ecb', $mcrypt_iv);
        mcrypt_module_close($mcrypt_module);

        return self::pkcs5_unpad($decrypted);
    }

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

    private static function pkcs5_unpad($text) {
        $pad = ord($text{strlen($text)-1});
        if ($pad > strlen($text)) return false;
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
        return substr($text, 0, -1 * $pad);
    }
}