Шифроване/декриптиране с помощта на mcrypt

Опитвате се да постигнете криптиране и декриптиране, като използвате следната стратегия, но завършвате предимно с произволни знаци.

class Crypt {

public static function encrypt($string, $account) {
    // create a random initialization vector to use with CBC encoding
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);

    $key = pack('H*', $account . $account);

    $output = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $string, MCRYPT_MODE_CBC, $iv);
    $output = $iv . $output;
    $output = base64_encode($output);
    $output = urlencode($output);

    return $output;
}

public static function decrypt($token, $account) {
    $ciphertext_dec = base64_decode($token);

    // retrieves the IV, iv_size should be created using mcrypt_get_iv_size()
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $iv_dec = substr($ciphertext_dec, 0, $iv_size);

    // retrieves the cipher text (everything except the $iv_size in the front)
    $ciphertext_dec = substr($ciphertext_dec, $iv_size);

    $key = pack('H*', $account . $account);

    $token = urldecode($token);

    $output = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $ciphertext_dec, MCRYPT_MODE_CBC, $iv_dec);
    $output = rtrim($output, "");
    return $output;
}

   }

Не мога да върна точните стойности, понякога дешифрира, но виждам някои ненужни стойности, но най-вече само произволни знаци.

$a = \Crypt::encrypt("MyPassword", "1974246e");
echo \Crypt::decrypt($a, "1974246e");

Редакции след дискусията

class Crypt {

public static function encrypt($data, $passphrase) {
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC); //create a random initialization vector to use with CBC encoding
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
    $key = pack('H*', $passphrase . $passphrase);
    return base64_encode($iv . mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_CBC, $iv));
}

public static function decrypt($data, $passphrase) {
    $data = base64_decode($data);
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC); //retrieves the IV, iv_size should be created using mcrypt_get_iv_size()
    $iv = substr($data, 0, $iv_size);
    $data = substr($data, $iv_size); //retrieves the cipher text (everything except the $iv_size in the front)
    $key = pack('H*', $passphrase . $passphrase);
    return rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_CBC, $iv), chr(0));
}
}

Употреба:

$pass = "MyPassword*&^*&^(*&^(";
$token = \Crypt::encrypt($pass, "1974246e8e8a479bb0233495e8a3ed12");
$answer = \Crypt::decrypt($token, "1974246e8e8a479bb0233495e8a3ed12");
echo $answer == $pass ? "yes" : "no";