About

This module provides a way to create and validate captchas in Wendy handlers. It uses GD::SecurityImage for picture creation. Only visual captchas are supported yet.

Package contents

Example using Wendy::Modules::Captcha

After you install a module on your host, example will be installed at address http://www.yourexamplehost.com/mod/captcha/test/. On that page you should be able to see and test generated captchas yourself.

Module API

Simplest example on how to create captcha:

use Wendy::Modules::Captcha;
...

my $cap = Wendy::Modules::Captcha -> new();
...


&add_replace( 'PUBLIC' => $cap -> get_public(),
	      'CAP_IMG_SRC' => $cap -> captcha_uri() );

Validating captcha:

use Wendy::Modules::Captcha;
...

my $cgi = $WOBJ -> { "CGI" }; # About $WOBJ
my $public = $cgi -> param( "public" );
my $user_guess = $cgi -> param( "user_guess" );

if( &check_captcha( $public,
                    $user_guess ) )
{
# Correct
} else
{
# Wrong!
}

Following methods are provided by this module:

• new

  Create mew Wendy::Modules::Captcha object. Example:

  my $captcha = Wendy::Modules::Captcha -> new( scramble => 0, width => 200, height => 60, font => '/usr/local/fonts/times.ttf' );

  Arguments:

  • Any GD::SecurityImage -> new(); arguments.

  Defaults:

  • scramble - 1
  • width - 300
  • height - 80
  • lines - 10
  • font - arial.ttf supplied with module

• set_text

  Sets captcha text. If called with empty arguments, text chosen randomly, length is default GD::SecurityImage length (rndmax). Be sure that text length will fit in captcha width. Example:

  $captcha -> set_text( 'Hello' );

  Arguments:

  • Text to set on captcha.

• get_public

  Get public captcha key. This key goes to html page form, along with captcha image. It contains password, and hash of ( $password . $captcha_text ). Thats all we need to check user (or robot :) guess. Example:

  my $public = $captcha -> get_public();

• get_pass

  Returns captcha password. Example:

  my $pass = $captcha -> get_pass();

• get_text

  Returns captcha text. Example:

  my $text = $captcha -> get_text();

• my_create

  Actually creates captcha, like GD::SecurityImage's create. Called automatically. Example:

  $captcha -> my_create();

• write_png_to_file

  Writes captcha image to png file. Will be called automatically with correct path and random file name, when you request captcha image URL. Example:

  $captcha -> write_png_to_file( '/tmp/test.png' ); # or: use Wendy::Config 'CONF_VARPATH'; ... my $rstr = md5_hex( rand() ); my $dst_file = File::Spec -> catfile( CONF_VARPATH, 'hosts', $WOBJ -> { 'HOST' } -> { 'host' }, 'htdocs', 'mod', 'captcha', 'var', $rstr . ".png" ); $captcha -> write_png_to_file( $dst_file );

  Arguments:

  • Path to file, to which we should write PNG captcha data.

• captcha_uri

  Rerurns captcha image to embed into your form into <img src="... Automatically calls set_text, my_create, write_png_to_file, etc, if needed. Returns ready and existing captcha URL. Example:

  my $img_url = $captcha -> captcha_uri();

• check_captcha

  Validates user input. Example:

  if( &check_captcha( $public, $user_guess ) ) { # Correct } else { # Wrong! }

  Arguments:

  • $public - captcha public string (see get_public method)
  • $user_guess - what user (or robot :) entered as our captcha guess

That's all about this module.