How to do MD5 with foreign characters? - php

Question

So I am making my custom highscore board in mobile game, using unity engine.
I setup my mysql database, and bought highscore asset from store, it works, but only with english user name. So basically it send user's name, score to .php script.
But I want that script also can receive korean characters as user's nickname. My users will use korean characters too as nickname not only english characters.
How can I achieve this?
Here are codes.
------------------(Highscore.cs at unity side)
WWWForm rsFm = new WWWForm();
rsFm.AddField("name",name);
// at here name field, I want to receive korean characters as well.
rsFm.AddField("tables",tables);
rsFm.AddField("hash",GetHash(name));
WWW rs = new WWW(registerUserURL,rsFm);
yield return rs;
..................
string GetHash(string usedString){ //Create a Hash to send to server
MD5 md5 = MD5.Create();
byte[] bytes = Encoding.ASCII.GetBytes(usedString+secretKey);
byte[] hash = md5.ComputeHash(bytes);
StringBuilder sb = new StringBuilder();
for(int i = 0; i < hash.Length; i++){
sb.Append(hash[i].ToString("x2"));
}
return sb.ToString();
}
RegisterUser.php
<?php
include('ServerConnect.php');
$connection = Connect();//Attempt to Connect to MYSQL Server & DataBase
//Get variables from unity
$name = $_POST['name'];
$date = strtotime(date("Y-m-d"));
$tables = $_POST['tables'];
//Security Check
$hash = $_POST['hash'];
if(CheckKey($hash,$name) == 'fail'){ //Check if hash is valid
echo 'Security Failure'; exit;
}
ServerConnect.php
function CheckKey($hash,$name){ //Check weather Md5 hash matches
global $secretKey;
$checkHash = md5($name.$secretKey);
if(strcmp($checkHash,$hash) == 0){
return 'pass'; //hash matches
}else{
return 'fail'; //hash failed
}
}
When I input korean character and send, console Result says "Security Failure" at above code.

Answer 1

like a user has stated before, you are using the wrong encoding if you will be using out of ascii chars (the case for korean, japanese, etc). You should be using Encoding.UTF8.GetBytes instead of Encoding.ASCII.GetBytes, take a look at https://msdn.microsoft.com/en-us/library/system.security.cryptography.md5%28v=vs.110%29.aspx for the example function GetMd5Hash. If you run ASCII md5, a different md5 will be generated.
The "salt" is the secret key you are using. $secretKey in PHP and secretKey in C#. You should read a little about security if you dont know what salt is, because if you dont you'll think you created a secure(r) system and you havent.
Hope it helps.