view logintets/login.html @ 5:e91d6f908222 boosterpack

[svn r7] finished!
author robert
date Tue, 08 Sep 2009 06:55:23 -0400
parents 477258d09353
children
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1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
2 "http://www.w3.org/TR/html4/loose.dtd">
3 <html>
4 <head>
5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
6 <title>AJAX Login System Demo</title>
7 <script src="md5.js" type="text/javascript">
8 // javascript md5 encoder originated from <http://pajhome.org.uk/crypt/md5/>
9 // used under license as outlined at <http://pajhome.org.uk/site/legal.html>
10 // Copyright (c) 1998 - 2002, Paul Johnston & Contributors
11 // All rights reserved.
12 </script>
13 <script src="xml_http_request.js" type="text/javascript">
14 // xml http request script modified slightly from that found at
15 // <http://www.webpasties.com/xmlHttpRequest/index.html>, which is
16 // Copyright 2005 Bill Bercik.
17 </script>
18 <script src="login_controller.js" type="text/javascript"></script>
19 <script src="login_presentation.js" type="text/javascript"></script>
20 <link rel="stylesheet" href="login.css" type="text/css" />
21 </head>
23 <body>
25 <h1>AJAX Login System Demo</h1>
26 <strong>Creating a secure login system using XMLHttpRequest</strong>
28 <p>This is an example of a login system that does not require page refreshes, but is still very secure. Valid
29 usernames and passwords for this demo are user1/pass1 and user2/pass2. Try these, and also incorrect passwords
30 to see the results.</p>
32 <p>Please note that this is not a functional form, your input will not go anywhere. It is solely for demonstrating
33 an XMLHttpRequest login system in javascript.</p>
35 <h2>Advantages</h2>
36 <ul>
37 <li>User does not need to refresh the page to login.</li>
38 <li>User is notified <em>instantly</em> on incorrect username/password combination.</li>
39 <li>Overall user experience is more seamless.</li>
40 <li>Password is not sent in plain text <em>ever</em> (more secure than traditional system).</li>
41 <li>Javascript convenience with server-side security (uses PHP/MySQL).</li>
42 <li>Uses one-time use random seed to hash the password before sending (making interceptions useless).</li>
43 </ul>
45 <h2>Disadvantages</h2>
46 <ul>
47 <li>System is more prone to brute force attacks.
48 <ul><li>Can be minimized by adding a delay after a certain number of attempts per username or per client.</li></ul></li>
49 <li>User may expect a login button.
50 <ul><li>One could still be added without reloading the page.</li></ul></li>
51 <li>Older versions of Safari cannot disable a password field.</li>
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>
53 </ul>
55 <h2>Demonstration</h2>
57 <div id="post_comment">
58 <form action="post" onSubmit="return false">
59 <div id="login" class="login">
60 <label for="username">Username: </label>
61 <input type="text" name="username" id="username" size=20>
62 <label for="password">Password: </label>
63 <input type="password" name="password" id="password" size=20>
64 <p id="message">Enter your username and password to log in.</p>
65 </div>
66 <label for="comments">Comments:</label>
67 <textarea rows="6" cols="80" id="comments"></textarea>
68 </form>
69 </div>
71 <h2>Source</h2>
72 <ul>
73 <li><a href="login.html">login.html</a></li>
74 <li><a href="login.css">login.css</a></li>
75 <li><a href="login_controller.js">login_controller.js</a></li>
76 <li><a href="login_presentation.js">login_presentation.js</a></li>
77 <li><a href="xml_http_request.js">xml_http_request.js</a></li>
78 <li><a href="md5.js">md5.js</a></li>
79 <li><a href="login.phps">login.php</a></li>
80 </ul>
82 <h2>Questions</h2>
83 <p><strong>Can I copy your code?</strong><br>
84 Sure, although I'd recommend you rewrite it as you go so you can actually learn
85 something useful. Also, passing someone else's code as your own is just uncool.
86 </p>
87 <p><strong>Why didn't you use [insert technology here]?</strong><br>
88 Basically I haven't done web development in close to a year, so I used what I knew best
89 (PHP/MySQL) and used the Javascript that I remembered, along with a little bit of
90 refreshing my memory. Perhaps I should have used object-oriented PHP or Javascript, but
91 this works. If it is slightly confusing, I apoligise, this is only meant as a proof-of-concept.</p>
92 <hr>
93 <p>Created: 28 Jan 2005.</p>
94 <p>Last updated: 1 Dec 2005. Copyright &copy; 2005.
95 </body>
96 </html>