fastcaptcha

fastcaptcha is another image captcha solution. It's simple and very fast.

INSTALL:

sudo gem install fastcaptcha

REQUIREMENT:

• ruby >= 1.9.1
• ruby development libraries (debian: ruby1.9.1-dev)
• opencv >= 2.1.0 development libraries (debian: libcv-dev libhighgui-dev)

USAGE:

require 'fastcaptcha' captcha = FastCaptcha.new # defaults to redis for caching and low complexity captchas. challenge = captcha.generate puts challenge.key puts challenge.image # PNG image data

require 'fastcaptcha' require 'moneta/memcache' captcha = FastCaptcha.new(Moneta::Memcache.new, 3) # use memcached instead & level 3 complexity challenge = captcha.generate puts challenge.key puts challenge.image # PNG image data

SINATRA HELPER:

• This adds a simple sinatra helper to display and validate captcha. Uses JQuery, so tough luck if you're using another Javascript library (patches welcome). If you're not using sinatra, you should be.

Add the sinatra helper to your application:

require 'sinatra/captcha' class MyApp < Sinatra::Base # ttl of captcha before user has to respond. set :captcha_ttl, 30

# complexity 1 is simple, 4 is wicked hard (makes segmentation very difficult).
set :captcha_level, 2

# use memcached instead of redis (default).
# set :captcha_cache, Moneta::Memcache

register Sinatra::Captcha

end

Add the captcha to your form using the captcha helper:

captcha(ajax: true, id: 'captcha_div')

Validate the captcha on form submission:

if captcha_correct? do_something else do_something_else end

You can have multiple captchas in the same page within different

elements. Just make sure captcha element ids are unique.

LICENSE:

GNU GPLv3, so its free and comes with no guarantees. If it brings down your website or burns down your house, I will not be held responsible. Use it at your own risk. You can read all about GNU here: http://www.gnu.org and GNU GPLv3 here: http://www.gnu.org/licenses/gpl.txt.