recaptchalib.php
260 lines
| 1 | <?php |
| 2 | /* |
| 3 | * This is a PHP library that handles calling reCAPTCHA. |
| 4 | * - Documentation and latest version |
| 5 | * http://recaptcha.net/plugins/php/ |
| 6 | * - Get a reCAPTCHA API Key |
| 7 | * https://www.google.com/recaptcha/admin/create |
| 8 | * - Discussion group |
| 9 | * http://groups.google.com/group/recaptcha |
| 10 | * |
| 11 | * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net |
| 12 | * AUTHORS: |
| 13 | * Mike Crawford |
| 14 | * Ben Maurer |
| 15 | * |
| 16 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 17 | * of this software and associated documentation files (the "Software"), to deal |
| 18 | * in the Software without restriction, including without limitation the rights |
| 19 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 20 | * copies of the Software, and to permit persons to whom the Software is |
| 21 | * furnished to do so, subject to the following conditions: |
| 22 | * |
| 23 | * The above copyright notice and this permission notice shall be included in |
| 24 | * all copies or substantial portions of the Software. |
| 25 | * |
| 26 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 27 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 28 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 29 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 30 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 31 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 32 | * THE SOFTWARE. |
| 33 | */ |
| 34 | |
| 35 | /** |
| 36 | * Encodes the given data into a query string format |
| 37 | * @param $data - array of string elements to be encoded |
| 38 | * @return string - encoded request |
| 39 | */ |
| 40 | function gglcptch_recaptcha_qsencode ($data) { |
| 41 | $req = ""; |
| 42 | foreach ( $data as $key => $value ) |
| 43 | $req .= $key . '=' . urlencode( stripslashes($value) ) . '&'; |
| 44 | |
| 45 | // Cut the last '&' |
| 46 | $req=substr($req,0,strlen($req)-1); |
| 47 | return $req; |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Submits an HTTP POST to a reCAPTCHA server |
| 52 | * @param string $host |
| 53 | * @param string $path |
| 54 | * @param array $data |
| 55 | * @param int port |
| 56 | * @return array response |
| 57 | */ |
| 58 | function gglcptch_recaptcha_http_post($host, $path, $data, $port = 80) { |
| 59 | |
| 60 | $req = gglcptch_recaptcha_qsencode ($data); |
| 61 | |
| 62 | $http_request = "POST $path HTTP/1.0\r\n"; |
| 63 | $http_request .= "Host: $host\r\n"; |
| 64 | $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n"; |
| 65 | $http_request .= "Content-Length: " . strlen($req) . "\r\n"; |
| 66 | $http_request .= "User-Agent: reCAPTCHA/PHP\r\n"; |
| 67 | $http_request .= "\r\n"; |
| 68 | $http_request .= $req; |
| 69 | |
| 70 | $response = ''; |
| 71 | if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) { |
| 72 | die ('Could not open socket'); |
| 73 | } |
| 74 | |
| 75 | fwrite($fs, $http_request); |
| 76 | |
| 77 | while ( !feof($fs) ) |
| 78 | $response .= fgets($fs, 1160); // One TCP-IP packet |
| 79 | fclose($fs); |
| 80 | $response = explode("\r\n\r\n", $response, 2); |
| 81 | |
| 82 | return $response; |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Gets the challenge HTML (javascript and non-javascript version). |
| 87 | * This is called from the browser, and the resulting reCAPTCHA HTML widget |
| 88 | * is embedded within the HTML form it was called from. |
| 89 | * @param string $pubkey A public key for reCAPTCHA |
| 90 | * @param string $error The error given by reCAPTCHA (optional, default is null) |
| 91 | * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false) |
| 92 | * @return string - The HTML to be embedded in the user's form. |
| 93 | */ |
| 94 | function gglcptch_recaptcha_get_html ($pubkey, $error = null, $use_ssl = false) |
| 95 | { |
| 96 | if ($pubkey == null || $pubkey == '') { |
| 97 | die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>"); |
| 98 | } |
| 99 | |
| 100 | if ($use_ssl) { |
| 101 | $server = "https://www.google.com/recaptcha/api"; |
| 102 | } else { |
| 103 | $server = "http://www.google.com/recaptcha/api"; |
| 104 | } |
| 105 | |
| 106 | $errorpart = ""; |
| 107 | if ($error) { |
| 108 | $errorpart = "&error=" . $error; |
| 109 | } |
| 110 | return '<script type="text/javascript" src="'. $server . '/challenge?&k=' . $pubkey . $errorpart . '"></script> |
| 111 | |
| 112 | <noscript> |
| 113 | <iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="320" frameborder="0"></iframe><br/> |
| 114 | <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea> |
| 115 | <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/> |
| 116 | </noscript>'; |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * A gglcptch_ReCaptchaResponse is returned from gglcptch_recaptcha_check_answer() |
| 121 | */ |
| 122 | class gglcptch_ReCaptchaResponse { |
| 123 | var $is_valid; |
| 124 | var $error; |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Calls an HTTP POST function to verify if the user's guess was correct |
| 129 | * @param string $privkey |
| 130 | * @param string $remoteip |
| 131 | * @param string $challenge |
| 132 | * @param string $response |
| 133 | * @param array $extra_params an array of extra variables to post to the server |
| 134 | * @return gglcptch_ReCaptchaResponse |
| 135 | */ |
| 136 | function gglcptch_recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array()) |
| 137 | { |
| 138 | if ($privkey == null || $privkey == '') { |
| 139 | die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>"); |
| 140 | } |
| 141 | |
| 142 | if ($remoteip == null || $remoteip == '') { |
| 143 | die ("For security reasons, you must pass the remote ip to reCAPTCHA"); |
| 144 | } |
| 145 | |
| 146 | |
| 147 | |
| 148 | //discard spam submissions |
| 149 | if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) { |
| 150 | $recaptcha_response = new gglcptch_ReCaptchaResponse(); |
| 151 | $recaptcha_response->is_valid = false; |
| 152 | $recaptcha_response->error = 'incorrect-captcha-sol'; |
| 153 | return $recaptcha_response; |
| 154 | } |
| 155 | |
| 156 | $response = gglcptch_recaptcha_http_post ("www.google.com", "/recaptcha/api/verify", |
| 157 | array ( |
| 158 | 'privatekey' => $privkey, |
| 159 | 'remoteip' => $remoteip, |
| 160 | 'challenge' => $challenge, |
| 161 | 'response' => $response |
| 162 | ) + $extra_params |
| 163 | ); |
| 164 | |
| 165 | $answers = explode ("\n", $response [1]); |
| 166 | $recaptcha_response = new gglcptch_ReCaptchaResponse(); |
| 167 | |
| 168 | if (trim ($answers [0]) == 'true') { |
| 169 | $recaptcha_response->is_valid = true; |
| 170 | } |
| 171 | else { |
| 172 | $recaptcha_response->is_valid = false; |
| 173 | $recaptcha_response->error = $answers [1]; |
| 174 | } |
| 175 | return $recaptcha_response; |
| 176 | |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * gets a URL where the user can sign up for reCAPTCHA. If your application |
| 181 | * has a configuration page where you enter a key, you should provide a link |
| 182 | * using this function. |
| 183 | * @param string $domain The domain where the page is hosted |
| 184 | * @param string $appname The name of your application |
| 185 | */ |
| 186 | function gglcptch_recaptcha_get_signup_url ($domain = null, $appname = null) { |
| 187 | return "https://www.google.com/recaptcha/admin/create?" . gglcptch_recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname)); |
| 188 | } |
| 189 | |
| 190 | function gglcptch_recaptcha_aes_pad($val) { |
| 191 | $block_size = 16; |
| 192 | $numpad = $block_size - (strlen ($val) % $block_size); |
| 193 | return str_pad($val, strlen ($val) + $numpad, chr($numpad)); |
| 194 | } |
| 195 | |
| 196 | /* Mailhide related code */ |
| 197 | |
| 198 | function gglcptch_recaptcha_aes_encrypt($val,$ky) { |
| 199 | if (! function_exists ("mcrypt_encrypt")) { |
| 200 | die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed."); |
| 201 | } |
| 202 | $mode=MCRYPT_MODE_CBC; |
| 203 | $enc=MCRYPT_RIJNDAEL_128; |
| 204 | $val=gglcptch_recaptcha_aes_pad($val); |
| 205 | return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"); |
| 206 | } |
| 207 | |
| 208 | |
| 209 | function gglcptch_recaptcha_mailhide_urlbase64 ($x) { |
| 210 | return strtr(base64_encode ($x), '+/', '-_'); |
| 211 | } |
| 212 | |
| 213 | /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */ |
| 214 | function gglcptch_recaptcha_mailhide_url($pubkey, $privkey, $email) { |
| 215 | if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) { |
| 216 | die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " . |
| 217 | "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>"); |
| 218 | } |
| 219 | |
| 220 | |
| 221 | $ky = pack('H*', $privkey); |
| 222 | $cryptmail = gglcptch_recaptcha_aes_encrypt ($email, $ky); |
| 223 | |
| 224 | return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . gglcptch_recaptcha_mailhide_urlbase64 ($cryptmail); |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * gets the parts of the email to expose to the user. |
| 229 | * eg, given johndoe@example,com return ["john", "example.com"]. |
| 230 | * the email is then displayed as john...@example.com |
| 231 | */ |
| 232 | function gglcptch_recaptcha_mailhide_email_parts ($email) { |
| 233 | $arr = preg_split("/@/", $email ); |
| 234 | |
| 235 | if (strlen ($arr[0]) <= 4) { |
| 236 | $arr[0] = substr ($arr[0], 0, 1); |
| 237 | } else if (strlen ($arr[0]) <= 6) { |
| 238 | $arr[0] = substr ($arr[0], 0, 3); |
| 239 | } else { |
| 240 | $arr[0] = substr ($arr[0], 0, 4); |
| 241 | } |
| 242 | return $arr; |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * Gets html to display an email address given a public an private key. |
| 247 | * to get a key, go to: |
| 248 | * |
| 249 | * http://www.google.com/recaptcha/mailhide/apikey |
| 250 | */ |
| 251 | function gglcptch_recaptcha_mailhide_html($pubkey, $privkey, $email) { |
| 252 | $emailparts = gglcptch_recaptcha_mailhide_email_parts ($email); |
| 253 | $url = gglcptch_recaptcha_mailhide_url ($pubkey, $privkey, $email); |
| 254 | |
| 255 | return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) . |
| 256 | "' onclick=\"window.open('" . htmlentities ($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]); |
| 257 | |
| 258 | } |
| 259 | |
| 260 | ?> |