UnityとPHPでデータを暗号化して通信をする

AES.cs

using System;
using System.IO;
using System.Security.Cryptography;

public static class AES {
	private static string KEY = "********************************"; 
	private static string IV = "********************************"; 
	
	public static string encrypt(string clearText) {
		return EncryptRJ256(KEY, IV, clearText);
	}
	
	public static string decrypt(string encryptText) {
		return DecryptRJ256(KEY, IV, encryptText);
	}
	
	public static string EncryptRJ256(string pkey, string piv, string clearText) {
		RijndaelManaged myRijndael = new RijndaelManaged();
		myRijndael.Padding = PaddingMode.Zeros;
		myRijndael.Mode = CipherMode.CBC;
		myRijndael.KeySize = 256;
		myRijndael.BlockSize = 256;
		
		byte[] key = System.Text.Encoding.UTF8.GetBytes(pkey);
		byte[] IV = System.Text.Encoding.UTF8.GetBytes(piv);
		
		ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, IV);
		MemoryStream ms = new MemoryStream();
		CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write);
		
		byte[] encryptByte = System.Text.Encoding.UTF8.GetBytes(clearText);
		
		cs.Write (encryptByte, 0, encryptByte.Length);
		cs.FlushFinalBlock();
		
		byte[] encrypted = ms.ToArray ();
		
		return Convert.ToBase64String (encrypted);
	}
	
	public static string DecryptRJ256(string pkey, string piv, string encryptedText) {
		RijndaelManaged myRijndael = new RijndaelManaged();
		myRijndael.Padding = PaddingMode.Zeros;
		myRijndael.Mode = CipherMode.CBC;
		myRijndael.KeySize = 256;
		myRijndael.BlockSize = 256;
		
		byte[] key = System.Text.Encoding.UTF8.GetBytes(pkey);
		byte[] iv = System.Text.Encoding.UTF8.GetBytes(piv);
		
		ICryptoTransform decryptor = myRijndael.CreateDecryptor(key, iv);
		byte[] encryptByte = Convert.FromBase64String(encryptedText);
		byte[] encrypted = new byte[encryptByte.Length];
		
		MemoryStream ms = new MemoryStream(encryptByte);
		CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read);
		cs.Read(encrypted, 0, encrypted.Length);
		
		return (System.Text.Encoding.UTF8.GetString(encrypted));
	}
}

decode.php

<?php
define('key', '********************************');
define('iv', '********************************');

$data = $_GET['data'];

$clearText = decryptRJ256(key, iv, $data);

header('Access-Control-Allow-Origin: *');
header('Content-Type: text/html; charset=utf-8');
echo $clearText;

function decryptRJ256($key, $iv, $decryptedText) {
    $decrypted = base64_decode($decryptedText);
    $clearText = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $decrypted, MCRYPT_MODE_CBC, $iv);
    return $clearText;
}

echo.php

<?php
define('key', '********************************');
define('iv', '********************************');

$data = $_GET['data'];

$encrypted = encryptRJ256(key, iv, $data);

header('Access-Control-Allow-Origin: *');
header('Content-Type: application/json; charset=utf-8');
echo json_encode(array('status' => 200, 'response' => $encrypted));

function encryptRJ256($key, $iv, $text) {
    $encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_CBC, $iv);
    return base64_encode($encrypted);
}