1 | <?php |
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2 | /* |
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3 | * This is a PHP library that handles calling reCAPTCHA. |
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4 | * - Documentation and latest version |
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5 | * http://recaptcha.net/plugins/php/ |
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6 | * - Get a reCAPTCHA API Key |
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7 | * https://www.google.com/recaptcha/admin/create |
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8 | * - Discussion group |
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9 | * http://groups.google.com/group/recaptcha |
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10 | * |
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11 | * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net |
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12 | * AUTHORS: |
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13 | * Mike Crawford |
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14 | * Ben Maurer |
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15 | * |
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16 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
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17 | * of this software and associated documentation files (the "Software"), to deal |
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18 | * in the Software without restriction, including without limitation the rights |
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19 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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20 | * copies of the Software, and to permit persons to whom the Software is |
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21 | * furnished to do so, subject to the following conditions: |
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22 | * |
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23 | * The above copyright notice and this permission notice shall be included in |
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24 | * all copies or substantial portions of the Software. |
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25 | * |
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26 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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27 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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28 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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29 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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30 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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31 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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32 | * THE SOFTWARE. |
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33 | */ |
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34 | |
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35 | /** |
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36 | * The reCAPTCHA server URL's |
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37 | */ |
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38 | define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api"); |
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39 | define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api"); |
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40 | define("RECAPTCHA_VERIFY_SERVER", "www.google.com"); |
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41 | |
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42 | /** |
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43 | * Encodes the given data into a query string format |
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44 | * @param $data - array of string elements to be encoded |
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45 | * @return string - encoded request |
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46 | */ |
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47 | function _recaptcha_qsencode ($data) { |
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48 | $req = ""; |
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49 | foreach ( $data as $key => $value ) |
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50 | $req .= $key . '=' . urlencode( stripslashes($value) ) . '&'; |
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51 | |
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52 | // Cut the last '&' |
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53 | $req=substr($req,0,strlen($req)-1); |
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54 | return $req; |
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55 | } |
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56 | |
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57 | |
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58 | |
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59 | /** |
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60 | * Submits an HTTP POST to a reCAPTCHA server |
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61 | * @param string $host |
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62 | * @param string $path |
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63 | * @param array $data |
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64 | * @param int port |
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65 | * @return array response |
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66 | */ |
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67 | function _recaptcha_http_post($host, $path, $data, $port = 80) { |
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68 | |
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69 | $req = _recaptcha_qsencode ($data); |
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70 | |
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71 | $http_request = "POST $path HTTP/1.0\r\n"; |
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72 | $http_request .= "Host: $host\r\n"; |
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73 | $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n"; |
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74 | $http_request .= "Content-Length: " . strlen($req) . "\r\n"; |
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75 | $http_request .= "User-Agent: reCAPTCHA/PHP\r\n"; |
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76 | $http_request .= "\r\n"; |
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77 | $http_request .= $req; |
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78 | |
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79 | $response = ''; |
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80 | if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) { |
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81 | die ('Could not open socket'); |
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82 | } |
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83 | |
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84 | fwrite($fs, $http_request); |
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85 | |
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86 | while ( !feof($fs) ) |
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87 | $response .= fgets($fs, 1160); // One TCP-IP packet |
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88 | fclose($fs); |
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89 | $response = explode("\r\n\r\n", $response, 2); |
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90 | |
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91 | return $response; |
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92 | } |
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93 | |
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94 | |
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95 | |
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96 | /** |
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97 | * Gets the challenge HTML (javascript and non-javascript version). |
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98 | * This is called from the browser, and the resulting reCAPTCHA HTML widget |
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99 | * is embedded within the HTML form it was called from. |
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100 | * @param string $pubkey A public key for reCAPTCHA |
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101 | * @param string $error The error given by reCAPTCHA (optional, default is null) |
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102 | * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false) |
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103 | |
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104 | * @return string - The HTML to be embedded in the user's form. |
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105 | */ |
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106 | function recaptcha_get_html ($pubkey, $error = null, $use_ssl = false) |
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107 | { |
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108 | if ($pubkey == null || $pubkey == '') { |
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109 | die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>"); |
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110 | } |
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111 | |
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112 | if ($use_ssl) { |
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113 | $server = RECAPTCHA_API_SECURE_SERVER; |
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114 | } else { |
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115 | $server = RECAPTCHA_API_SERVER; |
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116 | } |
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117 | |
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118 | $errorpart = ""; |
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119 | if ($error) { |
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120 | $errorpart = "&error=" . $error; |
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121 | } |
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122 | return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script> |
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123 | |
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124 | <noscript> |
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125 | <iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/> |
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126 | <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea> |
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127 | <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/> |
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128 | </noscript>'; |
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129 | } |
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130 | |
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131 | |
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132 | |
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133 | |
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134 | /** |
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135 | * A ReCaptchaResponse is returned from recaptcha_check_answer() |
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136 | */ |
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137 | class ReCaptchaResponse { |
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138 | var $is_valid; |
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139 | var $error; |
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140 | } |
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141 | |
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142 | |
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143 | /** |
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144 | * Calls an HTTP POST function to verify if the user's guess was correct |
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145 | * @param string $privkey |
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146 | * @param string $remoteip |
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147 | * @param string $challenge |
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148 | * @param string $response |
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149 | * @param array $extra_params an array of extra variables to post to the server |
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150 | * @return ReCaptchaResponse |
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151 | */ |
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152 | function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array()) |
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153 | { |
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154 | if ($privkey == null || $privkey == '') { |
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155 | die ("To use reCAPTCHA you must get an API key from <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>"); |
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156 | } |
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157 | |
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158 | if ($remoteip == null || $remoteip == '') { |
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159 | die ("For security reasons, you must pass the remote ip to reCAPTCHA"); |
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160 | } |
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161 | |
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162 | |
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163 | |
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164 | //discard spam submissions |
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165 | if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) { |
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166 | $recaptcha_response = new ReCaptchaResponse(); |
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167 | $recaptcha_response->is_valid = false; |
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168 | $recaptcha_response->error = 'incorrect-captcha-sol'; |
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169 | return $recaptcha_response; |
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170 | } |
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171 | |
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172 | $response = _recaptcha_http_post (RECAPTCHA_VERIFY_SERVER, "/recaptcha/api/verify", |
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173 | array ( |
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174 | 'privatekey' => $privkey, |
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175 | 'remoteip' => $remoteip, |
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176 | 'challenge' => $challenge, |
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177 | 'response' => $response |
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178 | ) + $extra_params |
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179 | ); |
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180 | |
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181 | $answers = explode ("\n", $response [1]); |
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182 | $recaptcha_response = new ReCaptchaResponse(); |
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183 | |
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184 | if (trim ($answers [0]) == 'true') { |
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185 | $recaptcha_response->is_valid = true; |
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186 | } |
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187 | else { |
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188 | $recaptcha_response->is_valid = false; |
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189 | $recaptcha_response->error = $answers [1]; |
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190 | } |
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191 | return $recaptcha_response; |
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192 | |
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193 | } |
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194 | |
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195 | /** |
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196 | * gets a URL where the user can sign up for reCAPTCHA. If your application |
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197 | * has a configuration page where you enter a key, you should provide a link |
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198 | * using this function. |
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199 | * @param string $domain The domain where the page is hosted |
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200 | * @param string $appname The name of your application |
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201 | */ |
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202 | function recaptcha_get_signup_url ($domain = null, $appname = null) { |
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203 | return "https://www.google.com/recaptcha/admin/create?" . _recaptcha_qsencode (array ('domains' => $domain, 'app' => $appname)); |
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204 | } |
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205 | |
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206 | function _recaptcha_aes_pad($val) { |
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207 | $block_size = 16; |
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208 | $numpad = $block_size - (strlen ($val) % $block_size); |
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209 | return str_pad($val, strlen ($val) + $numpad, chr($numpad)); |
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210 | } |
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211 | |
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212 | /* Mailhide related code */ |
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213 | |
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214 | function _recaptcha_aes_encrypt($val,$ky) { |
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215 | if (! function_exists ("mcrypt_encrypt")) { |
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216 | die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed."); |
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217 | } |
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218 | $mode=MCRYPT_MODE_CBC; |
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219 | $enc=MCRYPT_RIJNDAEL_128; |
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220 | $val=_recaptcha_aes_pad($val); |
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221 | return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"); |
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222 | } |
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223 | |
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224 | |
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225 | function _recaptcha_mailhide_urlbase64 ($x) { |
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226 | return strtr(base64_encode ($x), '+/', '-_'); |
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227 | } |
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228 | |
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229 | /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */ |
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230 | function recaptcha_mailhide_url($pubkey, $privkey, $email) { |
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231 | if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) { |
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232 | die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " . |
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233 | "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>"); |
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234 | } |
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235 | |
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236 | |
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237 | $ky = pack('H*', $privkey); |
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238 | $cryptmail = _recaptcha_aes_encrypt ($email, $ky); |
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239 | |
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240 | return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail); |
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241 | } |
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242 | |
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243 | /** |
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244 | * gets the parts of the email to expose to the user. |
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245 | * eg, given johndoe@example,com return ["john", "example.com"]. |
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246 | * the email is then displayed as john...@example.com |
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247 | */ |
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248 | function _recaptcha_mailhide_email_parts ($email) { |
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249 | $arr = preg_split("/@/", $email ); |
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250 | |
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251 | if (strlen ($arr[0]) <= 4) { |
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252 | $arr[0] = substr ($arr[0], 0, 1); |
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253 | } else if (strlen ($arr[0]) <= 6) { |
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254 | $arr[0] = substr ($arr[0], 0, 3); |
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255 | } else { |
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256 | $arr[0] = substr ($arr[0], 0, 4); |
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257 | } |
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258 | return $arr; |
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259 | } |
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260 | |
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261 | /** |
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262 | * Gets html to display an email address given a public an private key. |
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263 | * to get a key, go to: |
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264 | * |
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265 | * http://www.google.com/recaptcha/mailhide/apikey |
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266 | */ |
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267 | function recaptcha_mailhide_html($pubkey, $privkey, $email) { |
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268 | $emailparts = _recaptcha_mailhide_email_parts ($email); |
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269 | $url = recaptcha_mailhide_url ($pubkey, $privkey, $email); |
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270 | |
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271 | return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) . |
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272 | "' onclick=\"window.open('" . htmlentities ($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]); |
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273 | |
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274 | } |
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275 | |
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276 | |
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277 | ?> |
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