Gossamer Forum: Products: Links 2.0: Customization: Re: [Karl] Alternativ Solution to Antibot?: Edit Log

Good find! Incorporating this security feature is not too hard; the code is below.

1. Get a copy of the files (you have to register, but it's free), extract the zip file, and
edit captcha.pl (shown below) to suit your server. I put the files in a directory named captcha inside the admin directory, so that is how the code below is written. Upload the files captcha.pl, codes.txt, and the images directory into the captcha directory. I left out the data directory, and captchtest.cgi, as it won't be used.

Code:

##### SETTINGS #####
$captcha_datafolder = "/full/path/to/cgi-bin/links/admin/captcha"; # not web accessible to store database (no trailing slash)
$captcha_database = "$captcha_datafolder/codes.txt"; # path to database file
$captcha_imagesfolder = "$captcha_datafolder/images"; # not web accessible to store png image files (no trailing slash)
$captcha_outputfolder = "/full/path/to/www/links/captcha"; # path to store output (no trailing slash)
$captcha_webfolder = "http://your_url.com/links/captcha"; # url to outputfolder (no trailing slash)

2. Edit add.cgi, sub main as shown:

Code:
  # We are processing the form.   
 if (keys %in != 0) {   
$in{'captcha'} ?  &captcha : &site_html_add_failure("You are attempting to bypass our security.") and return; 
 }

3. Add this new sub to add.cgi, above sub process_form:

Code:

 sub captcha {  
#------------------------------------------  
    require "admin/captcha/captcha.pl";  
$code = ($in{'code'});  
$crypt = ($in{'crypt'});  
    if ($code && $crypt){
    # check code  
    $result = &checkCode($code,$crypt);
    if ($result == 1){  
        &process_form;  
    }  
    elsif ($result == -1){  
        &site_html_add_failure("<b>Failed!</b> Reason: code expired. Possible cause: code was issued too long ago. Try the new code below.") and return;  
    }  
    elsif ($result == -2){  
        &site_html_add_failure("<b>Failed!</b> Reason: invalid code (not in database). Possible causes: code already used or expired. Try the new code below.") and return;  
    }  
    elsif ($result == -3){  
        &site_html_add_failure("<b>Failed!</b> Reason: invalid code (code does not match crypt). Possible cause: characters not entered correctly. Try the new code below.") and return;  
        # note - once a solution is tried it is expired, even if it failed  
    }  
    else {  
        &site_html_add_failure("You did not enter the security code.") and return;  
    }  
}
} # end sub

4. Edit site_html_templates.pl as shown:

Code:
  sub site_html_add_form {  
# --------------------------------------------------------  
# This routine determines how the add form page will look like.       
&html_print_headers;      
my $get_captcha_form = &create_captcha_form; #in db_utils.pl
my $category = shift;  
    $category ?  
        ($category = qq~$category <input type=hidden name="Category" value="$category">~) :  
        ($category = &build_select_field ("Category", "$in{'Category'}"));  

    print &load_template ('add.html', {   
                                        Category => $category,  
captcha_form => $get_captcha_form,  
                                        %globals  
                                    });  
} sub site_html_add_failure {  
# --------------------------------------------------------  
# This routine determines how the add failure page will look like.     my ($errormsg) = shift;  
my $get_captcha_form = &create_captcha_form; # in db_utils.pl
    $in{'Category'} ?   
        ($in{'Category'} = qq~<input type=hidden name="Category" value="$in{'Category'}">$in{'Category'}~) :  
        ($in{'Category'} = &build_select_field ("Category"));  

    &html_print_headers;      
    print &load_template ('add_error.html', {   
                                        error => $errormsg,  
captcha_form => $get_captcha_form,  
                                        %in,  
                                        %globals  
                                    });}

5. Add a new sub to db_utils.pl, at the end of the file just abpve the '1;'. This is where you can edit the HTML code to match your site.

Code:
sub create_captcha_form {  
#-----------------------------------------------------------  
# Create the form for add.cgi securityrequire "admin/captcha/captcha.pl";  
    $crypt = &generateCode(8);    if ($crypt){  
    $i_width = $captcha_length*$captcha_width;  
    $output = qq|<img src="$captcha_webfolder/$crypt.png" width="$i_width" height="$captcha_height" border="0"><br>  
<input type="hidden" name="crypt" value="$crypt">  
Enter the characters you see in the image:   
<input type="text" name="code" value=""><br>  
Note: the numbers zero (0) and one (1) do not appear in the image. Refresh/reload this page for a new image. If you are uncertain of a character, take your best guess.|;  
    return $output;  
}  
    else{  
        &site_html_add_failure("Code not generated (file error)! Check to be sure that the script is properly configured.") and return;  
    }  
}

6. Edit the add.html and add_error.html templates as shown. The bold part is what is actually required.

Code:
                  <td><input name="Contact Email" value="" size="40"></td></tr>     
<tr><td align="right" valign="top">Security:</td>  
                    <td><%captcha_form%></td></tr>
            <tr><td></td><td><input type="SUBMIT" value="Add Resource" name="captcha"></td></tr>

That should do it! If you have any trouble, let me know.

Leonard
aka PerlFlunkie

Products: Links 2.0: Customization: Re: [Karl] Alternativ Solution to Antibot?: Edit Log

Here is the list of edits for this post

Last edited by:

Edit Log: