danielebarchiesi@2: <?php
danielebarchiesi@2: /*
danielebarchiesi@2:  * This is a PHP library that handles calling reCAPTCHA.
danielebarchiesi@2:  *    - Documentation and latest version
danielebarchiesi@2:  *          http://recaptcha.net/plugins/php/
danielebarchiesi@2:  *    - Get a reCAPTCHA API Key
danielebarchiesi@2:  *          https://www.google.com/recaptcha/admin/create
danielebarchiesi@2:  *    - Discussion group
danielebarchiesi@2:  *          http://groups.google.com/group/recaptcha
danielebarchiesi@2:  *
danielebarchiesi@2:  * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
danielebarchiesi@2:  * AUTHORS:
danielebarchiesi@2:  *   Mike Crawford
danielebarchiesi@2:  *   Ben Maurer
danielebarchiesi@2:  *
danielebarchiesi@2:  * Permission is hereby granted, free of charge, to any person obtaining a copy
danielebarchiesi@2:  * of this software and associated documentation files (the "Software"), to deal
danielebarchiesi@2:  * in the Software without restriction, including without limitation the rights
danielebarchiesi@2:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
danielebarchiesi@2:  * copies of the Software, and to permit persons to whom the Software is
danielebarchiesi@2:  * furnished to do so, subject to the following conditions:
danielebarchiesi@2:  *
danielebarchiesi@2:  * The above copyright notice and this permission notice shall be included in
danielebarchiesi@2:  * all copies or substantial portions of the Software.
danielebarchiesi@2:  *
danielebarchiesi@2:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
danielebarchiesi@2:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
danielebarchiesi@2:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
danielebarchiesi@2:  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
danielebarchiesi@2:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
danielebarchiesi@2:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
danielebarchiesi@2:  * THE SOFTWARE.
danielebarchiesi@2:  */
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * The reCAPTCHA server URL's
danielebarchiesi@2:  */
danielebarchiesi@2: define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api");
danielebarchiesi@2: define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api");
danielebarchiesi@2: define("RECAPTCHA_VERIFY_SERVER", "www.google.com");
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * Encodes the given data into a query string format
danielebarchiesi@2:  * @param $data - array of string elements to be encoded
danielebarchiesi@2:  * @return string - encoded request
danielebarchiesi@2:  */
danielebarchiesi@2: function _recaptcha_qsencode ($data) {
danielebarchiesi@2:         $req = "";
danielebarchiesi@2:         foreach ( $data as $key => $value )
danielebarchiesi@2:                 $req .= $key . '=' . urlencode( stripslashes($value) ) . '&';
danielebarchiesi@2: 
danielebarchiesi@2:         // Cut the last '&'
danielebarchiesi@2:         $req=substr($req,0,strlen($req)-1);
danielebarchiesi@2:         return $req;
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * Submits an HTTP POST to a reCAPTCHA server
danielebarchiesi@2:  * @param string $host
danielebarchiesi@2:  * @param string $path
danielebarchiesi@2:  * @param array $data
danielebarchiesi@2:  * @param int port
danielebarchiesi@2:  * @return array response
danielebarchiesi@2:  */
danielebarchiesi@2: function _recaptcha_http_post($host, $path, $data, $port = 80) {
danielebarchiesi@2: 
danielebarchiesi@2:         $req = _recaptcha_qsencode ($data);
danielebarchiesi@2: 
danielebarchiesi@2:         $http_request  = "POST $path HTTP/1.0\r\n";
danielebarchiesi@2:         $http_request .= "Host: $host\r\n";
danielebarchiesi@2:         $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
danielebarchiesi@2:         $http_request .= "Content-Length: " . strlen($req) . "\r\n";
danielebarchiesi@2:         $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
danielebarchiesi@2:         $http_request .= "\r\n";
danielebarchiesi@2:         $http_request .= $req;
danielebarchiesi@2: 
danielebarchiesi@2:         $response = '';
danielebarchiesi@2:         if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
danielebarchiesi@2:                 die ('Could not open socket');
danielebarchiesi@2:         }
danielebarchiesi@2: 
danielebarchiesi@2:         fwrite($fs, $http_request);
danielebarchiesi@2: 
danielebarchiesi@2:         while ( !feof($fs) )
danielebarchiesi@2:                 $response .= fgets($fs, 1160); // One TCP-IP packet
danielebarchiesi@2:         fclose($fs);
danielebarchiesi@2:         $response = explode("\r\n\r\n", $response, 2);
danielebarchiesi@2: 
danielebarchiesi@2:         return $response;
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * Gets the challenge HTML (javascript and non-javascript version).
danielebarchiesi@2:  * This is called from the browser, and the resulting reCAPTCHA HTML widget
danielebarchiesi@2:  * is embedded within the HTML form it was called from.
danielebarchiesi@2:  * @param string $pubkey A public key for reCAPTCHA
danielebarchiesi@2:  * @param string $error The error given by reCAPTCHA (optional, default is null)
danielebarchiesi@2:  * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
danielebarchiesi@2: 
danielebarchiesi@2:  * @return string - The HTML to be embedded in the user's form.
danielebarchiesi@2:  */
danielebarchiesi@2: function recaptcha_get_html ($pubkey, $error = null, $use_ssl = false)
danielebarchiesi@2: {
danielebarchiesi@2: 	if ($pubkey == null || $pubkey == '') {
danielebarchiesi@2: 		die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
danielebarchiesi@2: 	}
danielebarchiesi@2: 	
danielebarchiesi@2: 	if ($use_ssl) {
danielebarchiesi@2:                 $server = RECAPTCHA_API_SECURE_SERVER;
danielebarchiesi@2:         } else {
danielebarchiesi@2:                 $server = RECAPTCHA_API_SERVER;
danielebarchiesi@2:         }
danielebarchiesi@2: 
danielebarchiesi@2:         $errorpart = "";
danielebarchiesi@2:         if ($error) {
danielebarchiesi@2:            $errorpart = "&amp;error=" . $error;
danielebarchiesi@2:         }
danielebarchiesi@2:         return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>
danielebarchiesi@2: 
danielebarchiesi@2: 	<noscript>
danielebarchiesi@2:   		<iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
danielebarchiesi@2:   		<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
danielebarchiesi@2:   		<input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
danielebarchiesi@2: 	</noscript>';
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * A ReCaptchaResponse is returned from recaptcha_check_answer()
danielebarchiesi@2:  */
danielebarchiesi@2: class ReCaptchaResponse {
danielebarchiesi@2:         var $is_valid;
danielebarchiesi@2:         var $error;
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:   * Calls an HTTP POST function to verify if the user's guess was correct
danielebarchiesi@2:   * @param string $privkey
danielebarchiesi@2:   * @param string $remoteip
danielebarchiesi@2:   * @param string $challenge
danielebarchiesi@2:   * @param string $response
danielebarchiesi@2:   * @param array $extra_params an array of extra variables to post to the server
danielebarchiesi@2:   * @return ReCaptchaResponse
danielebarchiesi@2:   */
danielebarchiesi@2: function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())
danielebarchiesi@2: {
danielebarchiesi@2: 	if ($privkey == null || $privkey == '') {
danielebarchiesi@2: 		die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
danielebarchiesi@2: 	}
danielebarchiesi@2: 
danielebarchiesi@2: 	if ($remoteip == null || $remoteip == '') {
danielebarchiesi@2: 		die ("For security reasons, you must pass the remote ip to reCAPTCHA");
danielebarchiesi@2: 	}
danielebarchiesi@2: 
danielebarchiesi@2: 	
danielebarchiesi@2: 	
danielebarchiesi@2:         //discard spam submissions
danielebarchiesi@2:         if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
danielebarchiesi@2:                 $recaptcha_response = new ReCaptchaResponse();
danielebarchiesi@2:                 $recaptcha_response->is_valid = false;
danielebarchiesi@2:                 $recaptcha_response->error = 'incorrect-captcha-sol';
danielebarchiesi@2:                 return $recaptcha_response;
danielebarchiesi@2:         }
danielebarchiesi@2: 
danielebarchiesi@2:         $response = _recaptcha_http_post (RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify",
danielebarchiesi@2:                                           array (
danielebarchiesi@2:                                                  'privatekey' => $privkey,
danielebarchiesi@2:                                                  'remoteip' => $remoteip,
danielebarchiesi@2:                                                  'challenge' => $challenge,
danielebarchiesi@2:                                                  'response' => $response
danielebarchiesi@2:                                                  ) + $extra_params
danielebarchiesi@2:                                           );
danielebarchiesi@2: 
danielebarchiesi@2:         $answers = explode ("\n", $response [1]);
danielebarchiesi@2:         $recaptcha_response = new ReCaptchaResponse();
danielebarchiesi@2: 
danielebarchiesi@2:         if (trim ($answers [0]) == 'true') {
danielebarchiesi@2:                 $recaptcha_response->is_valid = true;
danielebarchiesi@2:         }
danielebarchiesi@2:         else {
danielebarchiesi@2:                 $recaptcha_response->is_valid = false;
danielebarchiesi@2:                 $recaptcha_response->error = $answers [1];
danielebarchiesi@2:         }
danielebarchiesi@2:         return $recaptcha_response;
danielebarchiesi@2: 
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * gets a URL where the user can sign up for reCAPTCHA. If your application
danielebarchiesi@2:  * has a configuration page where you enter a key, you should provide a link
danielebarchiesi@2:  * using this function.
danielebarchiesi@2:  * @param string $domain The domain where the page is hosted
danielebarchiesi@2:  * @param string $appname The name of your application
danielebarchiesi@2:  */
danielebarchiesi@2: function recaptcha_get_signup_url ($domain = null, $appname = null) {
danielebarchiesi@2: 	return "https://www.google.com/recaptcha/admin/create?" .  _recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname));
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: function _recaptcha_aes_pad($val) {
danielebarchiesi@2: 	$block_size = 16;
danielebarchiesi@2: 	$numpad = $block_size - (strlen ($val) % $block_size);
danielebarchiesi@2: 	return str_pad($val, strlen ($val) + $numpad, chr($numpad));
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: /* Mailhide related code */
danielebarchiesi@2: 
danielebarchiesi@2: function _recaptcha_aes_encrypt($val,$ky) {
danielebarchiesi@2: 	if (! function_exists ("mcrypt_encrypt")) {
danielebarchiesi@2: 		die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
danielebarchiesi@2: 	}
danielebarchiesi@2: 	$mode=MCRYPT_MODE_CBC;   
danielebarchiesi@2: 	$enc=MCRYPT_RIJNDAEL_128;
danielebarchiesi@2: 	$val=_recaptcha_aes_pad($val);
danielebarchiesi@2: 	return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: function _recaptcha_mailhide_urlbase64 ($x) {
danielebarchiesi@2: 	return strtr(base64_encode ($x), '+/', '-_');
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
danielebarchiesi@2: function recaptcha_mailhide_url($pubkey, $privkey, $email) {
danielebarchiesi@2: 	if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
danielebarchiesi@2: 		die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
danielebarchiesi@2: 		     "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>");
danielebarchiesi@2: 	}
danielebarchiesi@2: 	
danielebarchiesi@2: 
danielebarchiesi@2: 	$ky = pack('H*', $privkey);
danielebarchiesi@2: 	$cryptmail = _recaptcha_aes_encrypt ($email, $ky);
danielebarchiesi@2: 	
danielebarchiesi@2: 	return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail);
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * gets the parts of the email to expose to the user.
danielebarchiesi@2:  * eg, given johndoe@example,com return ["john", "example.com"].
danielebarchiesi@2:  * the email is then displayed as john...@example.com
danielebarchiesi@2:  */
danielebarchiesi@2: function _recaptcha_mailhide_email_parts ($email) {
danielebarchiesi@2: 	$arr = preg_split("/@/", $email );
danielebarchiesi@2: 
danielebarchiesi@2: 	if (strlen ($arr[0]) <= 4) {
danielebarchiesi@2: 		$arr[0] = substr ($arr[0], 0, 1);
danielebarchiesi@2: 	} else if (strlen ($arr[0]) <= 6) {
danielebarchiesi@2: 		$arr[0] = substr ($arr[0], 0, 3);
danielebarchiesi@2: 	} else {
danielebarchiesi@2: 		$arr[0] = substr ($arr[0], 0, 4);
danielebarchiesi@2: 	}
danielebarchiesi@2: 	return $arr;
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: /**
danielebarchiesi@2:  * Gets html to display an email address given a public an private key.
danielebarchiesi@2:  * to get a key, go to:
danielebarchiesi@2:  *
danielebarchiesi@2:  * http://www.google.com/recaptcha/mailhide/apikey
danielebarchiesi@2:  */
danielebarchiesi@2: function recaptcha_mailhide_html($pubkey, $privkey, $email) {
danielebarchiesi@2: 	$emailparts = _recaptcha_mailhide_email_parts ($email);
danielebarchiesi@2: 	$url = recaptcha_mailhide_url ($pubkey, $privkey, $email);
danielebarchiesi@2: 	
danielebarchiesi@2: 	return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
danielebarchiesi@2: 		"' onclick=\"window.open('" . htmlentities ($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]);
danielebarchiesi@2: 
danielebarchiesi@2: }
danielebarchiesi@2: 
danielebarchiesi@2: 
danielebarchiesi@2: ?>