This is a secure php login based on using a salt to add security to hashes. Of course sha1 would be a algorithm to use here, but for simplicity I will leave it out.
How this works is like this:
When the user registers for the page, they are given a long, and randomly generated "Salt", that is unique to their username. The salt is then added to the password, then all that is hashed. If your password was ABC123, a bruteforcer will get that pretty easily if your md5 hash was discovered. Now, if your hash was ABC1239ga8932ti9hgga9831h8, it would probably take a few million years to bruteforce that hash. Many sites use this technique, but the problem is, if you "salt" (added part of the password which is then hashed) is the same for all your users, then all it takes is for the attacker to find out your salt, and then he instantly has all of your users.
Having a random salt unique to each user would make cracking a large list of usernames and passwords almost total impossible, and not worth the effort to even try. I could almost give away passwords generated by this, and because they don't know each individual salt, they would never find the plaintext password.
I hope this all makes sense. If you are unclear about something just ask
Register.php
| php: |
$rUser = strip_tags($_REQUEST['u']); // username $rPass2 = md5(substr($_REQUEST['p2'],0,50) . $rSalt); // password - add randomized salt, this salt is inlcued with other user info $rEmail = strip_tags(stripslashes($_REQUEST['e'])); // This is the important part here // This is the important part here // This is the important part here // This is the important part here $rSalt = md5(rand(1,500000)); $rPass = md5(substr($_REQUEST['p'],0,50) . $rSalt); // password - add randomized salt, this salt is inlcued with other user info // Then all this is put into a database after being sanitized and validated |
Login.php
| php: |
<?php include("sql.php"); // Your SQL connection file, basic stuff session_start(); // Array to hold errors, at the end if there are no errors, then the finalizations are executed $errors = Array(); $lUser = strip_tags($_REQUEST['u']); // username $lPass = $_REQUEST['p']; // password // Check if the username exists $result = @mysql_query("SELECT * FROM `users` WHERE `name` = '$lUser' limit 1"); if(@mysql_num_rows($result) < 1) { $errors[] = "Account does not exist."; } // Get salt, check password $uSalt = @mysql_result($result, 0, 'users.salt'); // get the "salt" field $password = md5($lPass . $uSalt); // calculate password with salt // Check in the database if there is a username corresponding to the password hash we just calculated $result = @mysql_query("SELECT * FROM `users` WHERE `name` = '$lUser' and `pass` = '$password' limit 1"); if(@mysql_num_rows($result) < 1) // no results found { $errors[] = "Invalid Username or Password."; } // All error finding is done if(count($errors) == 0) { // set sessions $_SESSION['name'] = $lUser; $_SESSION['pass'] = $password; header("Location: game/index.php"); } else { // Print errors echo "The following errors occered: <br /><br />\n"; showErrors($errors); echo "<br /><br />"; } ?> |
.
. The real advantage that your method has is that the hacker couldn't just generate a list of common passwords and their hashes to compare with the database, he would have to generate that list for each different salt which would take a lot longer.