View source for Captcha

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Author: 2005 (( Howard Yeend)), 2008 ((user:TannSan TannSan))
License: GNU General Public License


  1. (( freeCap))
  1. (( Freecap Support))
  1. source:master/wacko/lib/captcha

  1. Fixed: Big-endian captcha issues has been tried and tested on both little and big endian systems. Now auto-works on both.
  2. Fixed: Big Endian issues with captcha system. Added a test which attempts to auto-detect the systems big-endian status. Needs testing on a big-endian system.

====freeCapsettings settings====

=====How can I make the image more readable?=====
freeCap is designed to be as customisable as possible. There are several variables you can change to make the text more readable:
  1. Change the ##bg_type## to ##0##, ##1## or ##2##
  1. Reduce the chunk factor
  1. Use more readable fonts
  1. Alter the fade factor

But bear in mind that increased human readability means decreased OCR-resistance. On the other hand, a CAPTCHA is more often simply a deterrent and the actual theoretical security matters little.

=====What can you do about accessibility issues?=====
Nothing, my suggestion for accessibility is to allow people to enter their details without passing the CAPTCHA, but send non-captcha’ed submittals to a ‘pending’ queue for manual review. It’s a much much simpler solution that still leaves the site accessible.

====WackoWiki related settings====
'captcha_new_comment' => 1,
'captcha_new_page' => 1,
'captcha_edit_page' => 1,
'captcha_registration' => 1,

===How to solve your freeCap problem===

====Where are the fonts/images?====
For security, they begin with a '##.##', which means that Apache won’t allow people to view them directly. Unfortunately, Windows also sees files beginning with a dot as hidden. Make sure that you’re set up to see hidden files in windows explorer (your file browser); go to the ‘Tools’ menu, then ‘Folder Options’, click the ‘View’ tab and make sure “Show hidden files and folders” has a check mark next to it. Press OK and you should see all the fonts and images appear on your local machine – now you can upload them.

====All I get is a blank image, or I get an error about "fopen(./.ht_freecap_font1.gdf):"====
Make sure that you have uploaded the fonts (see above), and the dictionary file.

If you have, try changing freecap’s config to use a randomly generated CAPTCHA; if it works after that, make sure the permissions on ##.ht_freecap_words## are set to ##700##.

====What does ‘service no longer available’ mean?====
freeCap has built-in brute force detection; this message is shown once a user has tried more than a reasonable amount of times to enter the text. As with almost all freeCap features, this is user-definable; to disable this feature, set $max_attempts to something massive like 999999999999999.
A future version will provide a less hacky way of disabling this feature.

====any – Fatal error: Call to undefined function: imagecreate() or image_anything()====
You must have GD installed in order to use freeCap.