annotate logintets/login.html @ 10:3b52ac950753 boosterpack tip

going to try to fix this thing
author Robert McIntyre <rlm@mit.edu>
date Mon, 27 Sep 2010 17:24:06 -0400
parents 477258d09353
children
rev   line source
robert@0 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
robert@0 2 "http://www.w3.org/TR/html4/loose.dtd">
robert@0 3 <html>
robert@0 4 <head>
robert@0 5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
robert@0 6 <title>AJAX Login System Demo</title>
robert@0 7 <script src="md5.js" type="text/javascript">
robert@0 8 // javascript md5 encoder originated from <http://pajhome.org.uk/crypt/md5/>
robert@0 9 // used under license as outlined at <http://pajhome.org.uk/site/legal.html>
robert@0 10 // Copyright (c) 1998 - 2002, Paul Johnston & Contributors
robert@0 11 // All rights reserved.
robert@0 12 </script>
robert@0 13 <script src="xml_http_request.js" type="text/javascript">
robert@0 14 // xml http request script modified slightly from that found at
robert@0 15 // <http://www.webpasties.com/xmlHttpRequest/index.html>, which is
robert@0 16 // Copyright 2005 Bill Bercik.
robert@0 17 </script>
robert@0 18 <script src="login_controller.js" type="text/javascript"></script>
robert@0 19 <script src="login_presentation.js" type="text/javascript"></script>
robert@0 20 <link rel="stylesheet" href="login.css" type="text/css" />
robert@0 21 </head>
robert@0 22
robert@0 23 <body>
robert@0 24
robert@0 25 <h1>AJAX Login System Demo</h1>
robert@0 26 <strong>Creating a secure login system using XMLHttpRequest</strong>
robert@0 27
robert@0 28 <p>This is an example of a login system that does not require page refreshes, but is still very secure. Valid
robert@0 29 usernames and passwords for this demo are user1/pass1 and user2/pass2. Try these, and also incorrect passwords
robert@0 30 to see the results.</p>
robert@0 31
robert@0 32 <p>Please note that this is not a functional form, your input will not go anywhere. It is solely for demonstrating
robert@0 33 an XMLHttpRequest login system in javascript.</p>
robert@0 34
robert@0 35 <h2>Advantages</h2>
robert@0 36 <ul>
robert@0 37 <li>User does not need to refresh the page to login.</li>
robert@0 38 <li>User is notified <em>instantly</em> on incorrect username/password combination.</li>
robert@0 39 <li>Overall user experience is more seamless.</li>
robert@0 40 <li>Password is not sent in plain text <em>ever</em> (more secure than traditional system).</li>
robert@0 41 <li>Javascript convenience with server-side security (uses PHP/MySQL).</li>
robert@0 42 <li>Uses one-time use random seed to hash the password before sending (making interceptions useless).</li>
robert@0 43 </ul>
robert@0 44
robert@0 45 <h2>Disadvantages</h2>
robert@0 46 <ul>
robert@0 47 <li>System is more prone to brute force attacks.
robert@0 48 <ul><li>Can be minimized by adding a delay after a certain number of attempts per username or per client.</li></ul></li>
robert@0 49 <li>User may expect a login button.
robert@0 50 <ul><li>One could still be added without reloading the page.</li></ul></li>
robert@0 51 <li>Older versions of Safari cannot disable a password field.</li>
robert@0 52 <li><strong>This code uses the MD5 encryption algorithm, which has since been proven to be less secure than previously thought. If you use this code, I strongly recommend you switch to a more secure encryption algorithm, such as SHA-1.</strong> For sites were security is not crucial, MD5 should suffice.</li>
robert@0 53 </ul>
robert@0 54
robert@0 55 <h2>Demonstration</h2>
robert@0 56
robert@0 57 <div id="post_comment">
robert@0 58 <form action="post" onSubmit="return false">
robert@0 59 <div id="login" class="login">
robert@0 60 <label for="username">Username: </label>
robert@0 61 <input type="text" name="username" id="username" size=20>
robert@0 62 <label for="password">Password: </label>
robert@0 63 <input type="password" name="password" id="password" size=20>
robert@0 64 <p id="message">Enter your username and password to log in.</p>
robert@0 65 </div>
robert@0 66 <label for="comments">Comments:</label>
robert@0 67 <textarea rows="6" cols="80" id="comments"></textarea>
robert@0 68 </form>
robert@0 69 </div>
robert@0 70
robert@0 71 <h2>Source</h2>
robert@0 72 <ul>
robert@0 73 <li><a href="login.html">login.html</a></li>
robert@0 74 <li><a href="login.css">login.css</a></li>
robert@0 75 <li><a href="login_controller.js">login_controller.js</a></li>
robert@0 76 <li><a href="login_presentation.js">login_presentation.js</a></li>
robert@0 77 <li><a href="xml_http_request.js">xml_http_request.js</a></li>
robert@0 78 <li><a href="md5.js">md5.js</a></li>
robert@0 79 <li><a href="login.phps">login.php</a></li>
robert@0 80 </ul>
robert@0 81
robert@0 82 <h2>Questions</h2>
robert@0 83 <p><strong>Can I copy your code?</strong><br>
robert@0 84 Sure, although I'd recommend you rewrite it as you go so you can actually learn
robert@0 85 something useful. Also, passing someone else's code as your own is just uncool.
robert@0 86 </p>
robert@0 87 <p><strong>Why didn't you use [insert technology here]?</strong><br>
robert@0 88 Basically I haven't done web development in close to a year, so I used what I knew best
robert@0 89 (PHP/MySQL) and used the Javascript that I remembered, along with a little bit of
robert@0 90 refreshing my memory. Perhaps I should have used object-oriented PHP or Javascript, but
robert@0 91 this works. If it is slightly confusing, I apoligise, this is only meant as a proof-of-concept.</p>
robert@0 92 <hr>
robert@0 93 <p>Created: 28 Jan 2005.</p>
robert@0 94 <p>Last updated: 1 Dec 2005. Copyright &copy; 2005.
robert@0 95 </body>
robert@0 96 </html>