10-29-2003, 02:23 PM
Im getting ready to put up a new section on my site but i want to prevent automated logins. I want to creat something that most of you have seen where it shows you some letters or numberes that i guess were automaticall generated to prevent automated logings and ask you to put in those same numbers or letters.
Can any of you WPW experts please tell me how I can do this (in detail...im not that good at this) or where i can go to find what im looking for.
10-29-2003, 02:47 PM
You would need some type of server side programming language and a graphics application.
PHP and GD can get this done. Here is a link on a tutorial on how to create images on the fly. http://www.phpbuilder.com/columns/rasmus19990124.php3
10-30-2003, 12:10 PM
I developed something like this one using PHP and GD. I was asked to develop something simple for a guestbook, and I based it on the IP address of the user (the logic probably being that any person wanting to genuinely use your servers, would not be using multiple proxies to login).
I took the IP address of the user. I took a random number (which was inserted as a hidden field).
I performed any sort of calculation on the two numbers, then took the MD5. I then took a preset number of the digits from the MD5 result, such as $result.$result.....
I took 8, then wrote this out as an image (robots cannot interpret images - incase they try, use a background such as a hashed background).
The same calculation is used in the authentication script, and just makes sure they match.
There are probably "off the shelf" scripts you can download for this, and include them in your projects.