Miscellaneous Hacks - reCAPTCHA!vB

THIS MODIFICATION SHOULD NOT BE USED WITH VBULLETIN 3.7+ AS IT IS A DEFAULT FEATURE.

Keywords: reCAPTCHA, CAPTCHA, spam, register

Description:
This modification will replaced the default vBulletin registration CAPTCHA with the newer, more advanced reCAPTCHA.

What is CAPTCHA/reCAPTCHA?:
A CAPTCHA is a program that can tell whether its user is a human or a computer. You've probably seen them ? colorful images with distorted text at the bottom of Web registration forms. CAPTCHAs are used by many websites to prevent abuse from "bots," or automated programs usually written to generate spam. No computer program can read distorted text as well as humans can, so bots cannot navigate sites protected by CAPTCHAs.

About 60 million CAPTCHAs are solved by humans around the world every day. In each case, roughly ten seconds of human time are being spent. Individually, that's not a lot of time, but in aggregate these little puzzles consume more than 150,000 hours of work each day. What if we could make positive use of this human effort? reCAPTCHA does exactly that by channeling the effort spent solving CAPTCHAs online into "reading" books.

To archive human knowledge and to make information more accessible to the world, multiple projects are currently digitizing physical books that were written before the computer age. The book pages are being photographically scanned, and then, to make them searchable, transformed into text using "Optical Character Recognition" (OCR). The transformation into text is useful because scanning a book produces images, which are difficult to store on small devices, expensive to download, and cannot be searched. The problem is that OCR is not perfect.



reCAPTCHA improves the process of digitizing books by sending words that cannot be read by computers to the Web in the form of CAPTCHAs for humans to decipher. More specifically, each word that cannot be read correctly by OCR is placed on an image and used as a CAPTCHA. This is possible because most OCR programs alert you when a word cannot be read correctly.

But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. The user is then asked to read both words. If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct.

Currently, we are helping to digitize books from the Internet Archive.

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Installation:

1. Download and unzip the recaptcha101.zip archive.
2. Upload the functions_recaptcha.php to your /includes/ directory.
3. Import the product-recaptcha.xml via the Product Manager.
4. Obtain a FREE public and private reCAPTCHA key here.
5. Make any desired configuration changes via AdminCP > vBulletin Options > reCAPTCHA Options
6. Make a backup of your register.php file, located in your forum root.
7. Perform ONE (1) of the following methods:
   • Method A:
     • Download the register-patch.zip archive, extract, then upload the register.patch file to your forum root, then apply the patch:
       
       *Note: Please note that this method requires a basic understanding of UNIX shell commands and requires shell access to your host. If you do not have either of these or you are unsure how to use GNU patch, I highly suggest performing Method B instead)
       
       

       # patch -b register.php < register.patch

       This will perform the file edits automatically. Once finished, you may delete the register.patch file.
   • Method B:
     Perform the following simple file edits:
     • IN register.php:
       1. FIND:
          
          PHP Code:

          eval('$imagereg = "' . fetch_template('imagereg') . '";'); 

          REPLACE WITH:
          
          PHP Code:

          $imagereg = recaptcha_get_html($vbulletin->options['recaptcha_publickey'], $error); 

       2. FIND AND REMOVE:
          
          PHP Code:

                          'imagestamp'          => TYPE_STR,
                'imagehash'           => TYPE_STR, 

       3. FIND:
          
          PHP Code:

                  // Check Reg Image
        if ($vbulletin->options['regimagecheck'] AND $vbulletin->options['regimagetype'])
        {
                require_once(DIR . '/includes/functions_regimage.php');
                if (!verify_regimage_hash($vbulletin->GPC['imagehash'], $vbulletin->GPC['imagestamp']))
                {
                        $userdata->error('register_imagecheck');
                }
        } 

          REPLACE WITH:
          
          PHP Code:

                  // Check Reg Image
        if ($vbulletin->options['regimagecheck'] AND $vbulletin->options['regimagetype'])
        {
                $resp = recaptcha_check_answer ($vbulletin->options['recaptcha_privatekey'],
                                                $_SERVER["REMOTE_ADDR"],
                                                $_POST["recaptcha_challenge_field"],
                                                $_POST["recaptcha_response_field"]);

                if (!$resp->is_valid)
                {
                        $userdata->error('register_imagecheck');
                }
        } 


NOTE: YOU MAY ALSO REPLACE THE CAPTCHA DISPLAYED TO GUESTS WHEN USING THE "CONTACT US" FORM BY FOLLOWING THE INSTRUCTIONS HERE.

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Tips, tricks and modifications:

• Apply "Method A" without shell access (DOCTOR DAN)
• Restore "image verification" frame around reCAPTCHA panel (DOCTOR DAN)

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Comments:
As with all my hacks, this modification is provided free of charge. However, if you find this product useful and have money burning a hole in your pocket, feel free to make a small donation, I won't mind.. really.

Version History:

• 1.0.0 - Initial release, here's to hoping...
• 1.0.1 - Woops! Forgot to include a aesthetic template edit in the original release. All is well, simply redownload and overwrite the XML. That's it!
• 1.1.0 - Added alternate language support. Now various reCAPTCHA tags and text will be displayed in your selected language. Also added a fieldset to the automatic template edits around the display block for a more uniform look (thanks DOCTOR DAN!).

Currently Known Bugs:

• None

* Please note that this modification was developed on a forum with a userbase of 1 (myself). I've tested it for basic functionality but I cannot guarantee functionality or behavior on your forum. So, please -- make backups before installing this product!

[magnus]

Originally Posted by GameWizard

But i find it confusing how yes, it makes it easier for humans, but at the same time could potentially make it easier for bots as well, could it not? All the bot would need to do is identify that your script is being used then attempt to read the word(s) which don't even need to be typed correctly! The first 3 letters or so seem to be the only requirement, the rest can be neglected or mistyped and the script still allows the user to continue...

There are 2 words. The challenge word and the variable word. The variable word can be anything. The challenge word must be typed 100% correctly. There's no 1, 2 or 3 letter minimum. Each challenge word must be 100% accurate.

Regardless of the variable word, this system, at worst, is no less secure than the default CAPTCHA. So there's no concern in that department.

The following is pure speculation, as the exact algorithim is intentionally not divulged:

It's possible that the variable word may have a minimum character requirement as the system may be able to determine the word length while not being able to exactly decipher the actual letters. Again, this is pure speculation on my part.

[Godders]

Hi there.
I am having some trouble using this.

I have made the changes as directed and placed the private and public keys where requested.
I get the following error
"To use reCAPTCHA you must get an API key from http://recaptcha.net/api/getkey"

Am i missing something? Fantastic script btw I cant wait to use it!

[TheInsaneManiac]

I like this, but what if I want the Image Verification border to stay there

[HP10T]

I get an error while importing via the product manager...
Database error in vBulletin 3.5.4:

Invalid SQL:

### INSERT QUERY GENERATED BY fetch_query_sql() ###
INSERT INTO plugin
(`active`, `executionorder`, `title`, `hookname`, `phpcode`, `product`)
VALUES
('1', '5', 'Automatically modify register template', 'parse_templates', 'if (isset($vbulletin->templatecache[\'register\']))\r\n{\r\n $find = \' $imagereg\';\r\n \r\n $append = \" <script type=\'text/javascript\'>\r\n var RecaptchaOptions = {\r\n theme : \'\" . $GLOBALS[\'vbulletin\']->options[\'recaptcha_theme\'] . \"\',\r\n tabindex : \" . $GLOBALS[\'vbulletin\']->options[\'recaptcha_tabindex\'] . \"\r\n };\r\n </script>\";\r\n\r\n $vbulletin->templatecache[\'register\'] = str_replace($find, $append . \"\\n\" . $find, $vbulletin->templatecache[\'register\']);\r\n\r\n unset($find, $append);\r\n}', 'recaptcha');

MySQL Error : Unknown column 'executionorder' in 'field list'
Error Number : 1054
Date : Monday, February 11th 2008 @ 02:13:16 PM
Script : http://utahnissans.com/forums/admincp/plugin.php
Referrer : http://utahnissans.com/forums/adminc...?do=productadd

[magnus]

Originally Posted by HP10T

I get an error while importing via the product manager...
Database error in vBulletin 3.5.4:

Invalid SQL:

### INSERT QUERY GENERATED BY fetch_query_sql() ###
INSERT INTO plugin
(`active`, `executionorder`, `title`, `hookname`, `phpcode`, `product`)
VALUES
('1', '5', 'Automatically modify register template', 'parse_templates', 'if (isset($vbulletin->templatecache[\'register\']))\r\n{\r\n $find = \' $imagereg\';\r\n \r\n $append = \" <script type=\'text/javascript\'>\r\n var RecaptchaOptions = {\r\n theme : \'\" . $GLOBALS[\'vbulletin\']->options[\'recaptcha_theme\'] . \"\',\r\n tabindex : \" . $GLOBALS[\'vbulletin\']->options[\'recaptcha_tabindex\'] . \"\r\n };\r\n </script>\";\r\n\r\n $vbulletin->templatecache[\'register\'] = str_replace($find, $append . \"\\n\" . $find, $vbulletin->templatecache[\'register\']);\r\n\r\n unset($find, $append);\r\n}', 'recaptcha');

MySQL Error : Unknown column 'executionorder' in 'field list'
Error Number : 1054
Date : Monday, February 11th 2008 @ 02:13:16 PM
Script : http://utahnissans.com/forums/admincp/plugin.php
Referrer : http://utahnissans.com/forums/adminc...?do=productadd

Well, you're trying to run a hack developed for vB3.6 on vB3.5 -- that's what happens.

If you're feeling frisky, you can edit the .xml and remove references to executionorder. This in no way guaranteed to work. It shouldn't break anything, however, you should always make backups just in case.

If you don't want to edit the file yourself, I've attached a modified .xml. Simply replace the on in the original archive with this.

[HP10T]

Thanks for the quick reply, I think I am going to upgrade to 3.6 first .

[Doctor Dan]

For those who would like to use "Method A" (the register.patch file) to modify their register.php file but do not have shell access (e.g. hosting services that only provide cPanel access), you may find this "trick" useful:

1. Upload the register.patch file to your forum's root directory.

2. Create a plain text file called runpatch.pl with the following contents:

#!/usr/bin/perl
print "content-type:text/html\n\n";
system('patch -b register.php < register.patch');

save it, and upload it to your forum's root directory.

3. Change the permissions on the runpatch.pl file that you just uploaded to 0755 so that you can execute the script.

4. In a web browser, type:

http://yourdomain/yourforum/runpatch.pl

The perl script will run, which in turn runs the patch command.

5. Delete the runpatch.pl file from your forum's root directory.

N.B.: This technique assumes that you can run perl scripts with system calls on the server where your forum resides, which is usually the case.

- Dan

[Doctor Dan]

A quick mod if you want to restore the "image verification" frame around the reCAPTCHA panel, just like how vBulletin's standard CAPTCHA panel appears:

In the template register find:

$imagereg

and replace it with:

<fieldset class="fieldset">
	<legend> $vbphrase[image_verification] </legend>
	$imagereg
</fieldset>

You can also center the reCAPTCHA panel within the frame by adding a "<center>" tag:

<fieldset class="fieldset">
	<legend> $vbphrase[image_verification] </legend>
	<center> $imagereg </center>
</fieldset>

- Dan

[magnus]

Thanks, Dan! I've linked your tips in the first post.

[Boofo]

Originally Posted by magnus

You're missing a close bracket ')' in the following block (highlighted in red):

// Check Reg Image
    if ($vbulletin->options['regimagecheck'] AND $vbulletin->options['regimagetype'])
    {
        $resp = recaptcha_check_answer ($vbulletin->options['recaptcha_privatekey'],
        $_SERVER["REMOTE_ADDR"],
        $_POST["recaptcha_challenge_field"],
        $_POST["recaptcha_response_field"]);
 
        if (!$resp->is_valid)
        {
        $userdata->error('register_imagecheck');
        }
    }

Also, why are you typing out the code changes manually? Just copy and paste them from the original post to make sure there are no typo's and to retain proper formatting.

You mean it's missing in this line, not the other one:

$resp = recaptcha_check_answer ($vbulletin->options['recaptcha_privatekey'],