CaptchaGen - Captcha Generator
We wrote this Captcha Generator script as we could not find a solid Captcha script written in perl which we could easily incorporate into our various sites that already have perl scripts that need some sort of anti spam mechanism. We accept that the requirement of ImageMagick and the relevant perl modules will put some off but in our opinion this makes for a better, more secure, Captcha image.
A Captcha (Completely Automated Public Turing Test to Tell Computers and Humans Apart) is aimed to stop bots from accessing areas of a web site that are meant for humans only, an example could be a spambot that posts spam as a comment to a blog entry.
With our CaptchaGen (Captcha Generator) script you can add this function to any area of your site with very little work if you have some perl experience. The actual script that does the work is more like a module in that your own scripts just 'require' it apart from setting half a dozen variables at the begining of the script. Take a look at Captcha Generator Methods for an brief idea of how the script can be used.
There are a number of Captcha's that exist but have been decoded for various reasons, and although we can't guarentee that Captcha Images generated by our CaptchaGen will not be, we have tried to make it as hard as we can by adding enough variables to produce a wide range of images and decide how hard the captcha image will be to decode, you can see some Captcha examples generated by the CaptchaGen script.
We have also included the facility to playback an audio file, for this to work you must have Flite installed on your server.
CaptchaGen features
see some Captcha examples generated by CaptchaGen.
- Uses existing ImageMagick patterns to overlay the image
- Uses system fonts as detected by ImageMagick.
- If 'flite' is installed on the server also offers audio
- Time limits the Captcha so if users take to long they have to try another (you set the time period)
- Captcha Code is stored on server and NOT in the web page
- Number of characters varies between 4 and 8 characters per image
- You can set the characters to use
- Either single color or gradient backgrounds
- Single color text or multicolor
- Single font or random font used for characters
- Add 'noise' to images
- Uses Ajax to reload image if user clicks on 'Refresh Image'
Requirements:
- *nix web server - this has been tested on Redhat and should work on any *nix server.
- perl 5.8
- CGI perl modules
- Digest::SHA1 perl modules
- Image::Magick perl module and ImageMagick (Min version 6, we know it works for ImageMagick version 6.2.x)
- Basic understanding of perl scripts (to incorporate CaptchaGen into your existing scripts)
Purchasing
Payment is made via Paypal, click on the 'Buy Now' button for the currency you wish to pay in and you will be taken to the Paypal website to make your payment. As soon as your payment has been completed your script will be emailed to you at the email address you used to pay with.
You are purchasing a single usage license with this script, multiple licenses are required if you intend to run on multiple sites. Make sure your server meets the above requirements before purchasing as refunds can not be given once the script has been emailed