<?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]); }