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captcha

Posted: Mon Oct 24, 2011 2:48 am
by darrel82
Hi,

I have been abandoned by my developer, the site is almost complete but one problem is I'm getting huge amounts of spam through the form below.
Could someone please help me in adding a captcha to the below form, very limited php knowledge by the way.

Thanks.

Code: Select all

<h2>Register</h2>
<?php 
	$attributes = array('action' => 'user/register');
	echo form_open($attributes); 
?>
<p>Desired userdame:</p>
<?php
	$data = array(
				  'name'        => 'username',
				  'id'          => 'username',
				  'maxlength'   => '100',
				  'size'        => '30',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	echo form_input($data);
?>
<p>Password:</p>
<?php
	$data = array(
				  'name'        => 'password',
				  'type'		=> 'password',
				  'id'          => 'password',
				  'maxlength'   => '100',
				  'size'        => '50',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	
	echo form_input($data);


?>
<p>Email address:</p>
<?php
	$data = array(
				  'name'        => 'email',
				  'id'          => 'email',
				  'maxlength'   => '100',
				  'size'        => '50',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	echo form_input($data);
?><?php

	
 $data = array(
				  'value'       => 'Register',
				);
 echo form_submit($data);

?>
<?php echo form_close(); ?>

Re: captcha

Posted: Mon Oct 24, 2011 6:11 am
by Celauran
Why not reCAPTCHA?

Re: captcha

Posted: Mon Oct 24, 2011 9:20 am
by egg82
beat me to it! reCAPTCHA is a great way to go. I was skeptical to try it, but it really is dead useful and versatile

by the way: Desired userdame
should be Desired username

Re: captcha

Posted: Mon Oct 24, 2011 9:11 pm
by darrel82
It looks great thanks for the advice on using recaptcha. I have set it up and all keys are correct, but the form submits regardless of the words typed into the captcha. any idea why?

Code: Select all

<h2>Register</h2>
 <html>
    <body><?php 
	$attributes = array('action' => 'user/register');
	echo form_open($attributes); 
?><form method="post" action="verify.php">
<p>Desired username:</p>
<?php
	$data = array(
				  'name'        => 'username',
				  'id'          => 'username',
				  'maxlength'   => '100',
				  'size'        => '30',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	echo form_input($data);
?>
<p>Password:</p>
<?php
	$data = array(
				  'name'        => 'password',
				  'type'		=> 'password',
				  'id'          => 'password',
				  'maxlength'   => '100',
				  'size'        => '50',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	
	echo form_input($data);


?>
<p>Email address:</p>
<?php
	$data = array(
				  'name'        => 'email',
				  'id'          => 'email',
				  'maxlength'   => '100',
				  'size'        => '50',
				  'style'       => 'width:50%;margin-left:20px;',
				);
	echo form_input($data);
?>
 <?php require_once('recaptchalib.php');
  $publickey = "mypublickey"; // you got this from the signup page
  echo recaptcha_get_html($publickey);


	
 $data = array(
				  'value'       => 'Register',
				);
 echo form_submit($data); 

?>
<?php echo form_close(); ?></form>


</html>
    </body>

Re: captcha

Posted: Mon Oct 24, 2011 10:29 pm
by egg82
This will check for a valid submission:

Code: Select all

require("include/recaptchalib.php");
$resp = recaptcha_check_answer("myprivatekey", $_SERVER["REMOTE_ADDR"], $recaptcha_challenge_field, $recaptcha_response_field);
if($resp->is_valid == false){
echo('<form action="./" method="post" id="redir">');
echo('<form action="./" method="post" id="redir">');
	echo("Captcha invalid");
	exit();
	//or whatever code you like...
}
a guide to installation here: http://inko9nito.wordpress.com/2007/12/ ... -with-php/

$publickey = "mypublickey" needs to contain your public key. Unless you edited it before you posted...

Re: captcha

Posted: Mon Oct 24, 2011 11:32 pm
by darrel82
Thanks for the reply, yea I edited the key before posting.

The trouble I'm having with that guide and I think the installation overall is that those instructions require a "process.php file (or whatever file you are using to process the form)."

The file which includes the form is register.php and the file location is /user/register.php. So it looks to me as if the file is processing itself without calling on another file to process

Code: Select all

$attributes = array('action' => 'user/register');
	echo form_open($attributes);
So the below code I have included in the verify.php file

Code: Select all

require("include/recaptchalib.php");
$resp = recaptcha_check_answer("myprivatekey", $_SERVER["REMOTE_ADDR"], $recaptcha_challenge_field, $recaptcha_response_field);
if($resp->is_valid == false){
echo('<form action="./" method="post" id="redir">');
echo('<form action="./" method="post" id="redir">');
        echo("Captcha invalid");
        exit();
But on the register.php file, if I place <form method="post" action="verify.php"> before "$attributes = array('action' => 'user/register');
echo form_open($attributes);" then the form just reloads blank but if I place it after, the form acts normally and registers without the need for verification.

Hope that makes sense :?

Re: captcha

Posted: Tue Oct 25, 2011 10:28 am
by egg82
here's what's on my server:

recaptchalib.php

Code: Select all

<?php
/*
 * This is a PHP library that handles calling reCAPTCHA.
 *    - Documentation and latest version
 *          http://recaptcha.net/plugins/php/
 *    - Get a reCAPTCHA API Key
 *          https://www.google.com/recaptcha/admin/create
 *    - Discussion group
 *          http://groups.google.com/group/recaptcha
 *
 * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
 * AUTHORS:
 *   Mike Crawford
 *   Ben Maurer
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * The reCAPTCHA server URL's
 */
define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api");
define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api");
define("RECAPTCHA_VERIFY_SERVER", "www.google.com");

/**
 * Encodes the given data into a query string format
 * @param $data - array of string elements to be encoded
 * @return string - encoded request
 */
function _recaptcha_qsencode ($data) {
        $req = "";
        foreach ( $data as $key => $value )
                $req .= $key . '=' . urlencode( stripslashes($value) ) . '&';

        // Cut the last '&'
        $req=substr($req,0,strlen($req)-1);
        return $req;
}



/**
 * Submits an HTTP POST to a reCAPTCHA server
 * @param string $host
 * @param string $path
 * @param array $data
 * @param int port
 * @return array response
 */
function _recaptcha_http_post($host, $path, $data, $port = 80) {

        $req = _recaptcha_qsencode ($data);

        $http_request  = "POST $path HTTP/1.0\r\n";
        $http_request .= "Host: $host\r\n";
        $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
        $http_request .= "Content-Length: " . strlen($req) . "\r\n";
        $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
        $http_request .= "\r\n";
        $http_request .= $req;

        $response = '';
        if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
                die ('Could not open socket');
        }

        fwrite($fs, $http_request);

        while ( !feof($fs) )
                $response .= fgets($fs, 1160); // One TCP-IP packet
        fclose($fs);
        $response = explode("\r\n\r\n", $response, 2);

        return $response;
}



/**
 * Gets the challenge HTML (javascript and non-javascript version).
 * This is called from the browser, and the resulting reCAPTCHA HTML widget
 * is embedded within the HTML form it was called from.
 * @param string $pubkey A public key for reCAPTCHA
 * @param string $error The error given by reCAPTCHA (optional, default is null)
 * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)

 * @return string - The HTML to be embedded in the user's form.
 */
function recaptcha_get_html ($pubkey, $error = null, $use_ssl = false)
{
	if ($pubkey == null || $pubkey == '') {
		die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
	}
	
	if ($use_ssl) {
                $server = RECAPTCHA_API_SECURE_SERVER;
        } else {
                $server = RECAPTCHA_API_SERVER;
        }

        $errorpart = "";
        if ($error) {
           $errorpart = "&error=" . $error;
        }
        return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>

	<noscript>
  		<iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
  		<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
  		<input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
	</noscript>';
}




/**
 * A ReCaptchaResponse is returned from recaptcha_check_answer()
 */
class ReCaptchaResponse {
        var $is_valid;
        var $error;
}


/**
  * Calls an HTTP POST function to verify if the user's guess was correct
  * @param string $privkey
  * @param string $remoteip
  * @param string $challenge
  * @param string $response
  * @param array $extra_params an array of extra variables to post to the server
  * @return ReCaptchaResponse
  */
function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())
{
	if ($privkey == null || $privkey == '') {
		die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
	}

	if ($remoteip == null || $remoteip == '') {
		die ("For security reasons, you must pass the remote ip to reCAPTCHA");
	}

	
	
        //discard spam submissions
        if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
                $recaptcha_response = new ReCaptchaResponse();
                $recaptcha_response->is_valid = false;
                $recaptcha_response->error = 'incorrect-captcha-sol';
                return $recaptcha_response;
        }

        $response = _recaptcha_http_post (RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify",
                                          array (
                                                 'privatekey' => $privkey,
                                                 'remoteip' => $remoteip,
                                                 'challenge' => $challenge,
                                                 'response' => $response
                                                 ) + $extra_params
                                          );

        $answers = explode ("\n", $response [1]);
        $recaptcha_response = new ReCaptchaResponse();

        if (trim ($answers [0]) == 'true') {
                $recaptcha_response->is_valid = true;
        }
        else {
                $recaptcha_response->is_valid = false;
                $recaptcha_response->error = $answers [1];
        }
        return $recaptcha_response;

}

/**
 * gets a URL where the user can sign up for reCAPTCHA. If your application
 * has a configuration page where you enter a key, you should provide a link
 * using this function.
 * @param string $domain The domain where the page is hosted
 * @param string $appname The name of your application
 */
function recaptcha_get_signup_url ($domain = null, $appname = null) {
	return "https://www.google.com/recaptcha/admin/create?" .  _recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname));
}

function _recaptcha_aes_pad($val) {
	$block_size = 16;
	$numpad = $block_size - (strlen ($val) % $block_size);
	return str_pad($val, strlen ($val) + $numpad, chr($numpad));
}

/* Mailhide related code */

function _recaptcha_aes_encrypt($val,$ky) {
	if (! function_exists ("mcrypt_encrypt")) {
		die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
	}
	$mode=MCRYPT_MODE_CBC;   
	$enc=MCRYPT_RIJNDAEL_128;
	$val=_recaptcha_aes_pad($val);
	return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
}


function _recaptcha_mailhide_urlbase64 ($x) {
	return strtr(base64_encode ($x), '+/', '-_');
}

/* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
function recaptcha_mailhide_url($pubkey, $privkey, $email) {
	if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
		die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
		     "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>");
	}
	

	$ky = pack('H*', $privkey);
	$cryptmail = _recaptcha_aes_encrypt ($email, $ky);
	
	return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail);
}

/**
 * gets the parts of the email to expose to the user.
 * eg, given johndoe@example,com return ["john", "example.com"].
 * the email is then displayed as john...@example.com
 */
function _recaptcha_mailhide_email_parts ($email) {
	$arr = preg_split("/@/", $email );

	if (strlen ($arr[0]) <= 4) {
		$arr[0] = substr ($arr[0], 0, 1);
	} else if (strlen ($arr[0]) <= 6) {
		$arr[0] = substr ($arr[0], 0, 3);
	} else {
		$arr[0] = substr ($arr[0], 0, 4);
	}
	return $arr;
}

/**
 * Gets html to display an email address given a public an private key.
 * to get a key, go to:
 *
 * http://www.google.com/recaptcha/mailhide/apikey
 */
function recaptcha_mailhide_html($pubkey, $privkey, $email) {
	$emailparts = _recaptcha_mailhide_email_parts ($email);
	$url = recaptcha_mailhide_url ($pubkey, $privkey, $email);
	
	return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
		"' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);

}


?>
regform.php

Code: Select all

echo('<form action="register.php" method="post">');
//form here
require("recaptchalib.php");
echo recaptcha_get_html("mypublickey");
echo('<br><input type="submit" value="'.$lang_register_register.'">');
echo("</form>");
register.php

Code: Select all

require("recaptchalib.php");
$resp = recaptcha_check_answer("myprivatekey", $_SERVER["REMOTE_ADDR"], $recaptcha_challenge_field, $recaptcha_response_field);
if($resp->is_valid == false){
	echo("Invalid captcha");
	exit();
}
//continue with registration