# Blosxom Plugin: recaptcha
# Author(s): Lars Engel <info@berlund.de>>
# Version: 2008-04-11
# Documentation: See the bottom of this file or type: perldoc recaptcha
# Requirements: The Blosxom writeback plugin and the Perl module
#				for using recaptcha <Captcha/reCAPTCHA.pm> by Andy Armstrong.
#				And of course a recaptcha account at <recaptcha.net/>

package recaptcha;



# --- Configurable variables -----

# Your recaptcha private key
my $private_key = 'Your private key here';

# Your recaptcha public key
my $pub_key = 'Your private key here';


# ----------
# Use this to display messages from recaptcha such as submitting a invalid response 
$msg = '';


# --------------------------------

$form = 1;
my $c = 1;


use Captcha::reCAPTCHA;
use CGI;


#
# Use this method in the writeback module to validate the captcha
#
sub validate{
	
	my $q = CGI->new;
	my $challenge = $q->param( 'recaptcha_challenge_field' );
	my $response = $q->param( 'recaptcha_response_field' );

	
	# Verify submission
	    my $result = $c->check_answer(
	        $private_key, $ENV{'REMOTE_ADDR'},
	        $challenge, $response
	    );

	    if ( $result->{is_valid} ) {
	        return 0;
	    }
	    else {
	        # Error
	        $error = $result->{error};
			$msg = "Sorry, that did not work. Please try again. <br/><small>($error)</small>";
			return 1;
	    }
}



sub start { 
	$c = Captcha::reCAPTCHA->new;
	$form = $c->get_html($pub_key);
    1;
}




1;

__END__

=head1 NAME

Blosxom Plug-in: recaptcha

=head1 SYNOPSIS

Provides CAPTCHA checking for writebacks (and some related) plugins.
The plugin uses the services of ReCaptcha.
<http://recaptcha.net/>.

=head2 QUICK START

Drop this plug-in file into your plug-ins directory 
(whatever you set as C<$plugin_dir> in blosxom.cgi).
Name it so that it will be loaded by blosxom before writebacks
plugin. For example if writebacks is called F<1writebacks>, name
F<recaptcha> as F<05recaptcha>.

Modify your F<foot.writeback> or where ever your Writeback form is located that it
displays the recaptcha form C<$recaptcha::form> and the potential error message
C<$recaptcha::msg>, e.g.

$recaptcha::form
$recaptcha::msg


Modify your writeback plugin in a place before the comment is saved to a file so
that you ran the validation method F<recaptcha::validate()> before. The method returns
zero if the validation was successful or one otherwise.
For instance can you look up the following piece of code in the F<start()> method

foreach ( ('', split /\//, $path) ) {
	$p .= "/$_";
	$p =~ s!^/!!;
	-d "$writeback_dir/$p" or mkdir "$writeback_dir/$p", 0777;
	chmod (0777,"$writeback_dir/$p");
}

and modify that it looks like this:

if(recaptcha::validate()>0){
	return 1;
}
  
	foreach ( ('', split /\//, $path) ) {
		$p .= "/$_";
		$p =~ s!^/!!;
		-d "$writeback_dir/$p" or mkdir "$writeback_dir/$p", 0777;
		chmod (0777,"$writeback_dir/$p");
}

Last but not least add your private and public key from ReCaptcha to 
the recaptcha module.

=back

=head2 VARIABLES


C<$recaptcha::form> Contains the ReCaptcha form
C<$wbcaptcha::msg> Contains a message if the captcha response is invalid

C<$wbcaptcha::private_key> Your recaptcha private key
C<$wbcaptcha::pub_key> Your recaptcha public key

=end text

=back

=head1 INSTALLATION

Drop wbcaptcha into your plug-ins directory (C<$blosxom::plugin_dir>).
Name it so that it will be loaded by blosxom before writebacks
plugin. For example if writebacks is called F<1writebacks>, name
F<recaptcha> as F<05recaptcha>.

=head1 CONFIGURATION

=head2 (REQUIRED) Add your reCaptcha keys

Add your reCaptcha keys as described in QUICK START, add the recaptcha form and message
to your writeback form as described in QUICK START.

=head1 AUTHOR

Lars Engel <info@berlund.de>, http://blog.berlund.de

=head1 SEE ALSO

Blosxom Plugin Docs: http://www.raelity.org/apps/blosxom/plugin.shtml
ReCaptcha: http://recaptcha.net/
ReCaptcha Perl module: http://search.cpan.org/dist/Captcha-reCAPTCHA/lib/Captcha/reCAPTCHA.pm

=head1 BUGS

Address bug reports and comments to <info@berlund.de>.

=head1 LICENSE

GNU General Public License v2.0, <http://www.gnu.org/licenses/gpl.html>