1 | <?php |
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2 | /** |
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3 | * The Strangecode Codebase - a general application development framework for PHP |
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4 | * For details visit the project site: <http://trac.strangecode.com/codebase/> |
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5 | * Copyright 2001-2012 Strangecode, LLC |
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6 | * |
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7 | * This file is part of The Strangecode Codebase. |
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8 | * |
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9 | * The Strangecode Codebase is free software: you can redistribute it and/or |
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10 | * modify it under the terms of the GNU General Public License as published by the |
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11 | * Free Software Foundation, either version 3 of the License, or (at your option) |
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12 | * any later version. |
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13 | * |
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14 | * The Strangecode Codebase is distributed in the hope that it will be useful, but |
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15 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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16 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more |
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17 | * details. |
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18 | * |
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19 | * You should have received a copy of the GNU General Public License along with |
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20 | * The Strangecode Codebase. If not, see <http://www.gnu.org/licenses/>. |
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21 | */ |
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22 | |
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23 | /** |
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24 | * Captcha.inc.php |
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25 | * |
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26 | * ASCII captcha system. |
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27 | * |
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28 | * @author Quinn Comendant <quinn@strangecode.com> |
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29 | * @version 1.0 |
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30 | ------------------------------------------------------------------------------------- |
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31 | // Example. |
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32 | |
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33 | // Instantiate new Captcha. This automatically generates a new 4-digit captcha number. |
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34 | $captcha = new Captcha(); |
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35 | |
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36 | <!-- HTML form for captcha --> |
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37 | <label for="sc-captcha"><?php echo _("Reverse Turing Test") ?></label> |
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38 | <p class="sc-help"><?php echo _("Please type the following number to prove you are a human. This is a measure to prevent spam robots from submitting this form.") ?></p> |
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39 | <pre style="font-size: 0.5em;"><?php $captcha->printAsciiNumber() ?></pre> |
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40 | <?php $captcha->printForm() ?> |
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41 | |
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42 | // Finally, test if the captcha was submitted correctly. |
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43 | if (!$captcha->valid()) { |
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44 | // Go back, show error. |
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45 | } |
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46 | |
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47 | // Or if you're using the FormValidator class. |
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48 | if (!$captcha->valid()) { |
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49 | $fv->addError('sc-captcha', _("The Captcha you entered is invalid. Please try again.")); |
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50 | } |
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51 | |
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52 | ------------------------------------------------------------------------------------- |
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53 | */ |
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54 | class Captcha { |
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55 | |
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56 | var $secret_key = 'some random seed text for the md5'; |
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57 | var $random_number; |
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58 | var $ascii_numbers = array( |
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59 | array( |
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60 | ' ##### ', |
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61 | ' ## ## ', |
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62 | '## ## ', |
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63 | '## ## ', |
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64 | '## ## ', |
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65 | ' ## ## ', |
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66 | ' ##### ', |
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67 | ), array( |
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68 | ' ## ', |
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69 | ' #### ', |
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70 | ' ## ', |
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71 | ' ## ', |
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72 | ' ## ', |
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73 | ' ## ', |
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74 | ' ###### ', |
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75 | ), array( |
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76 | ' ####### ', |
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77 | '## ## ', |
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78 | ' ## ', |
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79 | ' ####### ', |
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80 | '## ', |
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81 | '## ', |
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82 | '######### ', |
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83 | ), array( |
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84 | ' ####### ', |
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85 | '## ## ', |
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86 | ' ## ', |
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87 | ' ####### ', |
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88 | ' ## ', |
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89 | '## ## ', |
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90 | ' ####### ', |
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91 | ), array( |
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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 | ' ## ', |
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98 | ' ## ', |
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99 | ), array( |
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100 | '######## ', |
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101 | '## ', |
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102 | '## ', |
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103 | '####### ', |
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104 | ' ## ', |
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105 | '## ## ', |
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106 | ' ###### ', |
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107 | ), array( |
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108 | ' ####### ', |
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109 | '## ## ', |
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110 | '## ', |
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111 | '######## ', |
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112 | '## ## ', |
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113 | '## ## ', |
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114 | ' ####### ', |
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115 | ), array( |
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116 | '######## ', |
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117 | '## ## ', |
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118 | ' ## ', |
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119 | ' ## ', |
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120 | ' ## ', |
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121 | ' ## ', |
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122 | ' ## ', |
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123 | ), array( |
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124 | ' ####### ', |
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125 | '## ## ', |
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126 | '## ## ', |
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127 | ' ####### ', |
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128 | '## ## ', |
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129 | '## ## ', |
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130 | ' ####### ', |
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131 | ), array( |
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132 | ' ####### ', |
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133 | '## ## ', |
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134 | '## ## ', |
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135 | ' ######## ', |
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136 | ' ## ', |
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137 | '## ## ', |
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138 | ' ####### ', |
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139 | ) |
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140 | ); |
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141 | |
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142 | /** |
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143 | * Constructor. Initialized new random number. |
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144 | * |
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145 | * @access public |
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146 | * @author Quinn Comendant <quinn@strangecode.com> |
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147 | * @since 20 Jan 2006 13:08:22 |
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148 | */ |
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149 | function Captcha() |
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150 | { |
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151 | $app =& App::getInstance(); |
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152 | |
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153 | $this->secret_key = $app->getParam('signing_key'); |
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154 | $this->random_number = $this->_getRandomNumber(); |
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155 | } |
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156 | |
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157 | /** |
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158 | * Print ASCII number. |
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159 | * |
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160 | * @access public |
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161 | * @param mixed $num Number to convert. |
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162 | * @return string ASCII-ized number |
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163 | * @author Quinn Comendant <quinn@strangecode.com> |
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164 | * @since 07 Dec 2005 21:59:25 |
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165 | */ |
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166 | function getAsciiNumber($num=null) |
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167 | { |
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168 | $app =& App::getInstance(); |
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169 | |
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170 | if (!isset($num)) { |
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171 | $num = $this->random_number; |
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172 | } |
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173 | |
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174 | if (preg_match('/[^\d]/', $num)) { |
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175 | $app->logMsg(sprintf('Bad number: %s', $num), LOG_ERR, __FILE__, __LINE__); |
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176 | return false; |
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177 | } |
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178 | |
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179 | // Number must be an array of strings. |
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180 | $num = preg_split('//', strval($num), -1, PREG_SPLIT_NO_EMPTY); |
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181 | |
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182 | // All chars must be same height. |
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183 | $output = ''; |
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184 | $char_height = sizeof($this->ascii_numbers[0]); |
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185 | for ($i=0; $i<$char_height; $i++) { |
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186 | foreach ($num as $n) { |
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187 | $output .= $this->ascii_numbers[$n][$i]; |
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188 | } |
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189 | $output .= "\n"; |
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190 | } |
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191 | |
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192 | return $output; |
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193 | } |
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194 | |
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195 | /** |
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196 | * Prints the captcha ASCII numbers. |
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197 | * |
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198 | * @access public |
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199 | * @author Quinn Comendant <quinn@strangecode.com> |
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200 | * @since 07 Dec 2005 22:09:04 |
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201 | */ |
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202 | function printAsciiNumber() |
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203 | { |
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204 | $ascii = $this->getAsciiNumber($this->random_number); |
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205 | ?><pre id="sc-captcha"><?php echo $ascii ?></pre><?php |
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206 | } |
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207 | |
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208 | /** |
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209 | * Prints a form to enter captcha, including the required hidden hash form. |
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210 | * |
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211 | * @access public |
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212 | * @author Quinn Comendant <quinn@strangecode.com> |
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213 | * @since 07 Dec 2005 22:09:04 |
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214 | */ |
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215 | function printForm() |
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216 | { |
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217 | $hash = $this->_getMD5key($this->random_number); |
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218 | ?> |
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219 | <input name="sc-captcha-input" id="sc-captcha-input" class="sc-small" type="text" /> |
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220 | <input name="sc-captcha-hash" id="sc-captcha-hash" type="hidden" value="<?php echo $hash ?>" /> |
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221 | <?php |
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222 | } |
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223 | |
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224 | /** |
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225 | * Validate submitted number against ascii captcha. |
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226 | * Regenerate md5 hash from submitted captcha number and compare with posted hash. |
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227 | * |
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228 | * @access public |
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229 | * @return bool True if number matches hash or false if EVIL ROBOT. |
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230 | * @author Quinn Comendant <quinn@strangecode.com> |
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231 | * @since 07 Dec 2005 22:19:33 |
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232 | */ |
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233 | function valid() |
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234 | { |
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235 | $number = getFormData('sc-captcha-input'); |
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236 | $hash = getFormData('sc-captcha-hash'); |
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237 | |
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238 | if ('' == $number . $hash) { |
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239 | return false; |
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240 | } |
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241 | |
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242 | return $this->_getMD5key($number) == $hash; |
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243 | } |
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244 | |
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245 | /** |
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246 | * Generate random number 3-to-5 digits long. |
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247 | * |
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248 | * @access private |
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249 | * @return int Generated number. |
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250 | * @author Quinn Comendant <quinn@strangecode.com> |
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251 | * @since 07 Dec 2005 21:40:25 |
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252 | */ |
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253 | function _getRandomNumber() |
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254 | { |
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255 | return mb_substr(strval(rand(10000, 99999)), 0, rand(3, 5)); |
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256 | } |
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257 | |
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258 | /** |
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259 | * Generate md5 hash of number using secret key. |
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260 | * |
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261 | * @access private |
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262 | * @param string $input Input text to whack. |
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263 | * @return string md5 sum of input + seed |
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264 | * @author Quinn Comendant <quinn@strangecode.com> |
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265 | * @since 07 Dec 2005 21:53:35 |
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266 | */ |
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267 | function _getMD5key($input) |
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268 | { |
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269 | return md5($this->secret_key . $input); |
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270 | } |
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271 | |
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272 | } |
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273 | |
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274 | ?> |
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