anonym.to - URL redirection hack

till · July 2006

(Disclaimer: This is a rather small "hack", probably does not really qualify as an addon.)

I run a small private board, which is meant to be kept private. Here is something I came up with to hide the referer in URLs as people click a link from the board.

1)
(Using the default theme "vanilla", I copied the file "comments.php" from "/themes" to "/themes/vanilla".

2)
Then I went looking for a line where the "Body" of a comment is attached to the HTML container.
The line looks like this:

$CommentList .= '<div class="CommentBody" id="CommentBody_'.$Comment->CommentID.'">';
   $CommentList .= $Comment->Body.'
         </div>
      </li>';

3)
I changed this line to:

$CommentList .= '<div class="CommentBody" id="CommentBody_'.$Comment->CommentID.'">';
$CommentList .= preg_replace_callback(
                                "/href=\"http:\/\/(.*)\"/",
                                create_function(
                                    '$matches',
                                    '
                                    if (!is_array($matches) || (is_array($matches) && count($matches) == 0))
                                    {
                                        return \'\';
                                    }
                                    if (strstr($matches[0], \'http://anonym.to\'))
                                    {
                                        return $matches[0];
                                    }
                                    if (strstr($matches[0], $Configuration[\'BASE_URL\']))
                                    {
                                        return $matches[0];
                                    }
                                    $str = str_replace(\'href="\', \'\', $matches[0]);
                                    $str = str_replace(\'"\', \'\', $str);
                                    $str = \'href="http://anonym.to/?\' . urlencode($str) . \'"\';
                                    return $str;
                                    '
                                ),
                                ),
                                $Comment->Body
                                );
$CommentList .= '
         </div>
      </li>';

(Please note: The first line is just for reference and remains unchanged.)

This seems to be working with the latest vanilla (as of yesterday 1.0), I also have the following extensions installed: Attachment, Audioscrobbelerizer, CommentRemoval, Flickerizer, HTMLFormatter, New Applicants, Participate Threads, Quicktags and RSS2Feed.

I guess you can (ab)use this hack to do all sorts of things, like adding a frame to outgoing links, click tracking and so on.

Errata #1: Small bugfix.
Errata #2: Fixed so redirection is only applied to external links and not to attachments.

Cheers,
Till

chris · January 2009

this doesn't work for me - can someone tell me if there's something simple missing from the code (like a semi colon, or an else, etc) :D ty!

anonym.to - URL redirection hack

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