AESCrypt decryption between iOS and PHP

Question

I am having a heck of a time figuring out how to decrypt a string encrypted with the NSData+AESCrypt.m (Explained here)

I have been looking at a handful of other threads, but I only need the iDevice to send a string to a PHP file encrypted, and then it gets decrypted inside PHP (where it gets stored into a database).

This code :

NSString *encryptedString = [@"Hello" AES256EncryptWithKey:@"a16byteslongkey!"];
NSLog(@"The strign encrypted : %@",encryptedString);

Returns the string encrypted : 7opqbb7sEVNoXplyQv/X8g==

And here is my PHP code for decryption:

function decrypt_data($data, $key) {
    return mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key,$data,MCRYPT_MODE_ECB);
}

function unpadPKCS7($data, $blockSize) {
    $length = strlen ( $data );
    if ($length > 0) {
        $first = substr ( $data, - 1 );

        if (ord ( $first ) <= $blockSize) {
            for($i = $length - 2; $i > 0; $i --)
                if (ord ( $data [$i] != $first ))
                    break;

            return substr ( $data, 0, $i );
        }
    }
    return $data;
}

function decrypt_string($string) {
    $string = unpadPKCS7($string,128);
    $string = decrypt_data($string,"a16byteslongkey!");
    return $string;
}
die('
Basic :'.decrypt_string('7opqbb7sEVNoXplyQv/X8g=='));

UPDATE:

Been doing some MD5 decryption and experimenting a lot, but still far from achieving usable results. This is what I got so far:

Original string : Hello
AES256Encrypt result : 7opqbb7sEVNoXplyQv/X8
base64_decode Decrypted: îŠjm¾ìSh^™rBÿ×
mcrypt_rijndael_128 : Õ¯Öå«Ž(ás2’'u)
mcrypt_rijndael_128 & hex2bin : UÃ)Ä±+úy´e

Sadly, no matter how I bend and twist this, I just get jibberish. Can anyone see what I'm doing wrong?

AESCrypt decryption between iOS and PHP

4 Answers