PHP - Couple Of *basic* Questions.

Ok, so I'm trying to develop/remake a web based browser game that I used to play back in 2006.

I've got a fair amount set up, considering I knew nothing about php/mysql about a week ago.
However, I've made a registration process, login system, and the game pages (member only).
However, I was talking to some people the other day, and I'm using MD5 to encrypt the passwords. The suggestion given to me was to use SHA2 with Salt. The problem that I'm facing is that no matter what I try, I can't seem to get the system working.. I've followed the advice originally recieved: no success. I've followed a tutorial online: no success. SO, I was wondering if someone from here could help me.

My database has the extra 'salt' field setup..
and here's my uneddited working MD5 code:

Code: [Select]
<?php
   //Start session
   session_start();
   
   //Include database connection details
   require_once('config.php');
   
   //Array to store validation errors
   $errmsg_arr = array();
   
   //Validation error flag
   $errflag = false;
   
   //Connect to mysql server
   $link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
   if(!$link) {
      die('Failed to connect to server: ' . mysql_error());
   }
   
   //Select database
   $db = mysql_select_db(DB_DATABASE);
   if(!$db) {
      die("Unable to select database");
   }
   
   //Function to sanitize values received from the form. Prevents SQL injection
   function clean($str) {
      $str = @trim($str);
      if(get_magic_quotes_gpc()) {
         $str = stripslashes($str);
      }
      return mysql_real_escape_string($str);
   }
   
   //Sanitize the POST values
   $email = clean($_POST['email']);
   $login = clean($_POST['login']);
   $password = clean($_POST['password']);
   $cpassword = clean($_POST['cpassword']);
   $empire_name = clean($_POST['empire_name']);
   $race = clean($_POST['race']);
   $referrer = clean($_POST['referrer']);
   
   
   
   //Input Validations
   if($email == '') {
      $errmsg_arr[] = 'Email missing';
      $errflag = true;
   }
   if($login == '') {
      $errmsg_arr[] = 'Username missing';
      $errflag = true;
   }
   if($password == '') {
      $errmsg_arr[] = 'Password missing';
      $errflag = true;
   }
   if($cpassword == '') {
      $errmsg_arr[] = 'Confirm password missing';
      $errflag = true;
   }
   if( strcmp($password, $cpassword) != 0 ) {
      $errmsg_arr[] = 'Passwords do not match';
      $errflag = true;
   }
   if($empire_name == '') {
      $errmsg_arr[] = 'Empire Name missing';
      $errflag = true;
   }
   if($race == '') {
      $errmsg_arr[] = 'Race not selected';
      $errflag = true;
   }
   if(strlen($login) > 20) {
      $errmsg_arr[] = 'Username exceeds allowed charachter limit';
      $errflag = true;
   }
   if(strlen($empire_name) > 20) {
      $errmsg_arr[] = 'Empire Name exceeds allowed charachter limit';
      $errflag = true;
   }
   
     


   
   //Check for duplicate login ID
   if($login != '') {
      $qry = "SELECT * FROM members WHERE login='$login'";
      $result = mysql_query($qry); }
      if($result) {
         if(mysql_num_rows($result) > 0) {
            $errmsg_arr[] = 'Username already in use';
            $errflag = true;
         }
         @mysql_free_result($result);
      }
      else {
         die("Query failed");
      }
      
         //Check for duplicate Empire Name
   if($empire_name != '') {
      $qry = "SELECT * FROM members WHERE empire_name='$empire_name'";
      $result = mysql_query($qry); }
      if($result) {
         if(mysql_num_rows($result) > 0) {
            $errmsg_arr[] = 'Empire Name already in use';
            $errflag = true;
         }
         @mysql_free_result($result);
      }
      else {
         die("Query failed");
      }
   
   
   //If there are input validations, redirect back to the registration form
   if($errflag) {
      $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
      session_write_close();
      header("location:register-form.php");
      exit();
   }

   //Create INSERT query
$qry = "INSERT INTO members(email, login, passwd, empire_name, race, referrer) VALUES('$email','$login','".md5($_POST['password'])."','$empire_name','$race','$referrer')";
   $result = @mysql_query($qry);
   
   //Check whether the query was successful or not
   if($result) {
      header("location: register-success.php");
      exit();
   }else {
      die("Query failed");
   }
?>

My second question is:
I've got a set of permissions in my members database.. These are guest, player, mod and admin.
I'm currently running my updates page by calling the updates from the database... How would i go about adding a link to the first page you come to (after logging in) that can only be seen by members who are in the admin permission?
Because I'd like to make an admincp with a page to submit a form to the database that updates the updates page.. However, I'd rather the link to it only showed up for me and was invisible to other members..

Again, I'm only asking because I cant seem to find any information online at any tutorials or worksheets that I've come across.. And believe me, I've been searching quite a bit.. :/

Any help would be very much appreciated..
Cheers,
/zythion/