Total Complexity | 80 |
Total Lines | 569 |
Duplicated Lines | 0 % |
Changes | 0 |
Complex classes like Security often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Security, and based on these observations, apply Extract Interface, too.
1 | <?php |
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40 | class Security |
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41 | { |
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42 | public static $clean = []; |
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43 | |||
44 | /** |
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45 | * Checks if the absolute path (directory) given is really under the |
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46 | * checker path (directory). |
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47 | * |
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48 | * @param string $abs_path Absolute path to be checked (with trailing slash) |
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49 | * @param string $checker_path Checker path under which the path |
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50 | * should be (absolute path, with trailing slash, get it from api_get_path(SYS_COURSE_PATH)) |
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51 | * |
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52 | * @return bool True if the path is under the checker, false otherwise |
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53 | */ |
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54 | public static function check_abs_path(string $abs_path, string $checker_path): bool |
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84 | } |
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85 | |||
86 | public static function cleanPath(string $absPath): string |
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87 | { |
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88 | $absPath = str_replace(['//', '../'], ['/', ''], $absPath); |
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89 | |||
90 | return str_replace("\\", '/', realpath($absPath)); |
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91 | } |
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92 | |||
93 | /** |
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94 | * Checks if the relative path (directory) given is really under the |
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95 | * checker path (directory). |
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96 | * |
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97 | * @param string $rel_path Relative path to be checked (relative to the current directory) (with trailing slash) |
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98 | * @param string $checker_path Checker path under which the path |
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99 | * should be (absolute path, with trailing slash, get it from api_get_path(SYS_COURSE_PATH)) |
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100 | * |
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101 | * @return bool True if the path is under the checker, false otherwise |
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102 | */ |
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103 | public static function check_rel_path(string $rel_path, string $checker_path): bool |
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104 | { |
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105 | // The checker path must be set. |
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106 | if (empty($checker_path)) { |
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107 | return false; |
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108 | } |
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109 | $current_path = getcwd(); // No trailing slash. |
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110 | if ('/' != substr($rel_path, -1, 1)) { |
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111 | $rel_path = '/'.$rel_path; |
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112 | } |
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113 | $abs_path = $current_path.$rel_path; |
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114 | $true_path = str_replace("\\", '/', realpath($abs_path)); |
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115 | $found = strpos($true_path.'/', $checker_path); |
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116 | if (0 === $found) { |
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117 | return true; |
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118 | } |
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119 | |||
120 | return false; |
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121 | } |
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122 | |||
123 | /** |
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124 | * Filters dangerous filenames (*.php[.]?* and .htaccess) and returns it in |
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125 | * a non-executable form (for PHP and htaccess, this is still vulnerable to |
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126 | * other languages' files extensions). |
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127 | * |
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128 | * @param string $filename Unfiltered filename |
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129 | */ |
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130 | public static function filter_filename(string $filename): string |
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131 | { |
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132 | return disable_dangerous_file($filename); |
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133 | } |
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134 | |||
135 | public static function getTokenFromSession(string $prefix = ''): string |
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136 | { |
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137 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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138 | |||
139 | return Session::read($secTokenVariable); |
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140 | } |
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141 | |||
142 | /** |
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143 | * This function checks that the token generated in get_token() has been kept (prevents |
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144 | * Cross-Site Request Forgeries attacks). |
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145 | * |
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146 | * @param string $requestType The array in which to get the token ('get' or 'post') |
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147 | * @param ?FormValidator $form |
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148 | * |
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149 | * @return bool True if it's the right token, false otherwise |
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150 | */ |
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151 | public static function check_token(string $requestType = 'post', FormValidator $form = null, string $prefix = ''): bool |
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152 | { |
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153 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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154 | $sessionToken = Session::read($secTokenVariable); |
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155 | switch ($requestType) { |
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156 | case 'request': |
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157 | if (!empty($sessionToken) && isset($_REQUEST[$secTokenVariable]) && $sessionToken === $_REQUEST[$secTokenVariable]) { |
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158 | return true; |
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159 | } |
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160 | |||
161 | return false; |
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162 | case 'get': |
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163 | if (!empty($sessionToken) && isset($_GET[$secTokenVariable]) && $sessionToken === $_GET[$secTokenVariable]) { |
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164 | return true; |
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165 | } |
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166 | |||
167 | return false; |
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168 | case 'post': |
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169 | if (!empty($sessionToken) && isset($_POST[$secTokenVariable]) && $sessionToken === $_POST[$secTokenVariable]) { |
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170 | return true; |
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171 | } |
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172 | |||
173 | return false; |
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174 | case 'form': |
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175 | $token = $form->getSubmitValue('protect_token'); |
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176 | |||
177 | if (!empty($sessionToken) && !empty($token) && $sessionToken === $token) { |
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178 | return true; |
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179 | } |
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180 | |||
181 | return false; |
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182 | default: |
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183 | if (!empty($sessionToken) && isset($requestType) && $sessionToken === $requestType) { |
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184 | return true; |
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185 | } |
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186 | } |
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187 | |||
188 | return false; // Just in case, don't let anything slip. |
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189 | } |
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190 | |||
191 | /** |
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192 | * Checks the user agent of the client as recorder by get_ua() to prevent |
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193 | * most session hijacking attacks. |
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194 | * |
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195 | * @return bool True if the user agent is the same, false otherwise |
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196 | */ |
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197 | public static function check_ua(): bool |
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198 | { |
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199 | $security = Session::read('sec_ua'); |
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200 | $securitySeed = Session::read('sec_ua_seed'); |
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201 | |||
202 | if ($security === $_SERVER['HTTP_USER_AGENT'].$securitySeed) { |
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203 | return true; |
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204 | } |
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205 | |||
206 | return false; |
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207 | } |
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208 | |||
209 | /** |
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210 | * Clear the security token from the session. |
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211 | */ |
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212 | public static function clear_token(string $prefix = ''): void |
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213 | { |
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214 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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215 | |||
216 | Session::erase($secTokenVariable); |
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217 | } |
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218 | |||
219 | /** |
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220 | * This function sets a random token to be included in a form as a hidden field |
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221 | * and saves it into the user's session. Returns an HTML form element |
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222 | * This later prevents Cross-Site Request Forgeries by checking that the user is really |
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223 | * the one that sent this form in knowingly (this form hasn't been generated from |
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224 | * another website visited by the user at the same time). |
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225 | * Check the token with check_token(). |
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226 | * |
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227 | * @return string Hidden-type input ready to insert into a form |
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228 | */ |
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229 | public static function get_HTML_token(string $prefix = ''): string |
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230 | { |
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231 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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232 | $token = md5(uniqid(rand(), true)); |
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233 | $string = '<input type="hidden" name="'.$secTokenVariable.'" value="'.$token.'" />'; |
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234 | Session::write($secTokenVariable, $token); |
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235 | |||
236 | return $string; |
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237 | } |
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238 | |||
239 | /** |
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240 | * This function sets a random token to be included in a form as a hidden field |
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241 | * and saves it into the user's session. |
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242 | * This later prevents Cross-Site Request Forgeries by checking that the user is really |
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243 | * the one that sent this form in knowingly (this form hasn't been generated from |
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244 | * another website visited by the user at the same time). |
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245 | * Check the token with check_token(). |
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246 | * |
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247 | * @return string Token |
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248 | */ |
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249 | public static function get_token($prefix = ''): string |
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250 | { |
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251 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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252 | $token = md5(uniqid(rand(), true)); |
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253 | Session::write($secTokenVariable, $token); |
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254 | |||
255 | return $token; |
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256 | } |
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257 | |||
258 | public static function get_existing_token(string $prefix = ''): string |
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259 | { |
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260 | $secTokenVariable = self::generateSecTokenVariable($prefix); |
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261 | $token = Session::read($secTokenVariable); |
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262 | if (!empty($token)) { |
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263 | return $token; |
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264 | } else { |
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265 | return self::get_token($prefix); |
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266 | } |
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267 | } |
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268 | |||
269 | /** |
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270 | * Gets the user agent in the session to later check it with check_ua() to prevent |
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271 | * most cases of session hijacking. |
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272 | */ |
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273 | public static function get_ua() |
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278 | } |
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279 | |||
280 | /** |
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281 | * This function returns a variable from the clean array. If the variable doesn't exist, |
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282 | * it returns null. |
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283 | * |
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284 | * @param string $varname Variable name |
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285 | * |
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286 | * @return mixed Variable or NULL on error |
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287 | */ |
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288 | public static function get(string $varname) |
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289 | { |
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290 | if (isset(self::$clean[$varname])) { |
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291 | return self::$clean[$varname]; |
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292 | } |
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293 | |||
294 | return null; |
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295 | } |
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296 | |||
297 | /** |
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298 | * This function tackles the XSS injections. |
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299 | * Filtering for XSS is very easily done by using the htmlentities() function. |
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300 | * This kind of filtering prevents JavaScript snippets to be understood as such. |
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301 | * |
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302 | * @param string|array $var The variable to filter for XSS, this params can be a string or an array (example : array(x,y)) |
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303 | * @param ?int $user_status The user status,constant allowed (STUDENT, COURSEMANAGER, ANONYMOUS, COURSEMANAGERLOWSECURITY) |
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304 | * |
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305 | * @return mixed Filtered string or array |
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306 | */ |
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307 | public static function remove_XSS($var, int $user_status = null, bool $filter_terms = false) |
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308 | { |
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309 | if ($filter_terms) { |
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310 | $var = self::filter_terms($var); |
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311 | } |
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312 | |||
313 | if (empty($user_status)) { |
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314 | if (api_is_anonymous()) { |
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315 | $user_status = ANONYMOUS; |
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316 | } else { |
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317 | if (api_is_allowed_to_edit()) { |
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318 | $user_status = COURSEMANAGER; |
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319 | } else { |
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320 | $user_status = STUDENT; |
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321 | } |
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322 | } |
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323 | } |
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324 | |||
325 | if (COURSEMANAGERLOWSECURITY == $user_status) { |
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326 | return $var; // No filtering. |
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327 | } |
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328 | |||
329 | static $purifier = []; |
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330 | if (!isset($purifier[$user_status])) { |
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331 | $cache_dir = api_get_path(SYS_ARCHIVE_PATH).'Serializer'; |
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332 | if (!file_exists($cache_dir)) { |
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333 | $mode = api_get_permissions_for_new_directories(); |
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334 | mkdir($cache_dir, $mode); |
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335 | } |
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336 | $config = HTMLPurifier_Config::createDefault(); |
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337 | $config->set('Cache.SerializerPath', $cache_dir); |
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338 | $config->set('Core.Encoding', api_get_system_encoding()); |
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339 | $config->set('HTML.Doctype', 'XHTML 1.0 Transitional'); |
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340 | $config->set('HTML.MaxImgLength', '2560'); |
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341 | $config->set('HTML.TidyLevel', 'light'); |
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342 | $config->set('Core.ConvertDocumentToFragment', false); |
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343 | $config->set('Core.RemoveProcessingInstructions', true); |
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344 | |||
345 | if ('true' == api_get_setting('enable_iframe_inclusion')) { |
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346 | $config->set('Filter.Custom', [new AllowIframes()]); |
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347 | } |
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348 | |||
349 | // Shows _target attribute in anchors |
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350 | $config->set('Attr.AllowedFrameTargets', ['_blank', '_top', '_self', '_parent']); |
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351 | |||
352 | if (STUDENT == $user_status) { |
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353 | global $allowed_html_student; |
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354 | $config->set('HTML.SafeEmbed', true); |
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355 | $config->set('HTML.SafeObject', true); |
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356 | $config->set('Filter.YouTube', true); |
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357 | $config->set('HTML.FlashAllowFullScreen', true); |
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358 | $config->set('HTML.Allowed', $allowed_html_student); |
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359 | } elseif (COURSEMANAGER == $user_status) { |
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360 | global $allowed_html_teacher; |
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361 | $config->set('HTML.SafeEmbed', true); |
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362 | $config->set('HTML.SafeObject', true); |
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363 | $config->set('Filter.YouTube', true); |
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364 | $config->set('HTML.FlashAllowFullScreen', true); |
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365 | $config->set('HTML.Allowed', $allowed_html_teacher); |
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366 | } else { |
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367 | global $allowed_html_anonymous; |
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368 | $config->set('HTML.Allowed', $allowed_html_anonymous); |
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369 | } |
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370 | |||
371 | // We need it for example for the flv player (ids of surrounding div-tags have to be preserved). |
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372 | $config->set('Attr.EnableID', true); |
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373 | $config->set('CSS.AllowImportant', true); |
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374 | // We need for the flv player the css definition display: none; |
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375 | $config->set('CSS.AllowTricky', true); |
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376 | $config->set('CSS.Proprietary', true); |
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377 | |||
378 | // Allow uri scheme. |
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379 | $config->set('URI.AllowedSchemes', [ |
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380 | 'http' => true, |
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381 | 'https' => true, |
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382 | 'mailto' => true, |
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383 | 'ftp' => true, |
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384 | 'nntp' => true, |
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385 | 'news' => true, |
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386 | 'data' => true, |
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387 | ]); |
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388 | |||
389 | // Allow <video> tag |
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390 | //$config->set('HTML.Doctype', 'HTML 4.01 Transitional'); |
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391 | $config->set('HTML.SafeIframe', true); |
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392 | |||
393 | // Set some HTML5 properties |
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394 | $config->set('HTML.DefinitionID', 'html5-definitions'); // unqiue id |
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395 | $config->set('HTML.DefinitionRev', 1); |
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396 | if ($def = $config->maybeGetRawHTMLDefinition()) { |
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397 | // https://html.spec.whatwg.org/dev/media.html#the-video-element |
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398 | $def->addElement( |
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399 | 'video', |
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400 | 'Block', |
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401 | 'Optional: (source, Flow) | (Flow, source) | Flow', |
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402 | 'Common', |
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403 | [ |
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404 | 'src' => 'URI', |
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405 | 'type' => 'Text', |
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406 | 'width' => 'Length', |
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407 | 'height' => 'Length', |
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408 | 'poster' => 'URI', |
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409 | 'preload' => 'Enum#auto,metadata,none', |
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410 | 'controls' => 'Bool', |
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411 | ] |
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412 | ); |
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413 | // https://html.spec.whatwg.org/dev/media.html#the-audio-element |
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414 | $def->addElement( |
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415 | 'audio', |
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416 | 'Block', |
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417 | 'Optional: (source, Flow) | (Flow, source) | Flow', |
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418 | 'Common', |
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419 | [ |
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420 | 'autoplay' => 'Bool', |
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421 | 'src' => 'URI', |
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422 | 'loop' => 'Bool', |
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423 | 'preload' => 'Enum#auto,metadata,none', |
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424 | 'controls' => 'Bool', |
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425 | 'muted' => 'Bool', |
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426 | ] |
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427 | ); |
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428 | $def->addElement( |
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429 | 'source', |
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430 | 'Block', |
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431 | 'Flow', |
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432 | 'Common', |
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433 | ['src' => 'URI', 'type' => 'Text'] |
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434 | ); |
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435 | } |
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436 | |||
437 | $purifier[$user_status] = new HTMLPurifier($config); |
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438 | } |
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439 | |||
440 | if (is_array($var)) { |
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441 | return $purifier[$user_status]->purifyArray($var); |
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442 | } else { |
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443 | return $purifier[$user_status]->purify($var); |
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444 | } |
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445 | } |
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446 | |||
447 | /** |
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448 | * Filter content. |
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449 | * |
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450 | * @param string $text to be filtered |
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451 | */ |
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452 | public static function filter_terms(string $text): string |
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453 | { |
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454 | static $bad_terms = []; |
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455 | |||
456 | if (empty($bad_terms)) { |
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457 | $list = api_get_setting('filter_terms'); |
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458 | if (!empty($list)) { |
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459 | $list = explode("\n", $list); |
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460 | $list = array_filter($list); |
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461 | if (!empty($list)) { |
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462 | foreach ($list as $term) { |
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463 | $term = str_replace(["\r\n", "\r", "\n", "\t"], '', $term); |
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464 | $html_entities_value = api_htmlentities($term, ENT_QUOTES, api_get_system_encoding()); |
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465 | $bad_terms[] = $term; |
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466 | if ($term != $html_entities_value) { |
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467 | $bad_terms[] = $html_entities_value; |
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468 | } |
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469 | } |
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470 | } |
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471 | $bad_terms = array_filter($bad_terms); |
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472 | } |
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473 | } |
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474 | |||
475 | $replace = '***'; |
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476 | if (!empty($bad_terms)) { |
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477 | // Fast way |
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478 | $new_text = str_ireplace($bad_terms, $replace, $text); |
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479 | $text = $new_text; |
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480 | } |
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481 | |||
482 | return $text; |
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483 | } |
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484 | |||
485 | /** |
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486 | * This method provides specific protection (against XSS and other kinds of attacks) |
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487 | * for static images (icons) used by the system. |
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488 | * Image paths are supposed to be given by programmers - people who know what they do, anyway, |
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489 | * this method encourages a safe practice for generating icon paths, without using heavy solutions |
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490 | * based on HTMLPurifier for example. |
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491 | * |
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492 | * @param string $image_path the input path of the image, it could be relative or absolute URL |
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493 | * |
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494 | * @return string returns sanitized image path or an empty string when the image path is not secure |
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495 | * |
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496 | * @author Ivan Tcholakov, March 2011 |
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497 | */ |
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498 | public static function filter_img_path(string $image_path): string |
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499 | { |
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500 | static $allowed_extensions = ['png', 'gif', 'jpg', 'jpeg', 'svg', 'webp']; |
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501 | $image_path = htmlspecialchars(trim($image_path)); // No html code is allowed. |
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502 | // We allow static images only, query strings are forbidden. |
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503 | if (false !== strpos($image_path, '?')) { |
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504 | return ''; |
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505 | } |
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506 | if (false !== ($pos = strpos($image_path, ':'))) { |
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507 | // Protocol has been specified, let's check it. |
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508 | if (false !== stripos($image_path, 'javascript:')) { |
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509 | // Javascript everywhere in the path is not allowed. |
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510 | return ''; |
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511 | } |
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512 | // We allow only http: and https: protocols for now. |
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513 | //if (!preg_match('/^https?:\/\//i', $image_path)) { |
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514 | // return ''; |
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515 | //} |
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516 | if (0 !== stripos($image_path, 'http://') && 0 !== stripos($image_path, 'https://')) { |
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517 | return ''; |
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518 | } |
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519 | } |
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520 | // We allow file extensions for images only. |
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521 | //if (!preg_match('/.+\.(png|gif|jpg|jpeg)$/i', $image_path)) { |
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522 | // return ''; |
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523 | //} |
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524 | if (false !== ($pos = strrpos($image_path, '.'))) { |
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525 | if (!in_array(strtolower(substr($image_path, $pos + 1)), $allowed_extensions)) { |
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526 | return ''; |
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527 | } |
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528 | } else { |
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529 | return ''; |
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530 | } |
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531 | |||
532 | return $image_path; |
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533 | } |
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534 | |||
535 | /** |
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536 | * Get password requirements |
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537 | * It checks config value 'password_requirements' or uses the "classic" |
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538 | * Chamilo password requirements. |
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539 | */ |
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540 | public static function getPasswordRequirements(): array |
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541 | { |
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542 | // Default |
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543 | $requirements = [ |
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544 | 'min' => [ |
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545 | 'lowercase' => 0, |
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546 | 'uppercase' => 0, |
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547 | 'numeric' => 2, |
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548 | 'length' => 5, |
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549 | 'specials' => 1, |
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550 | ], |
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551 | ]; |
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552 | |||
553 | $passwordRequirements = api_get_setting('security.password_requirements', true); |
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554 | if (is_array($passwordRequirements)) { |
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555 | $requirements = $passwordRequirements; |
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556 | } |
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557 | |||
558 | return ['min' => $requirements['min']]; |
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559 | } |
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560 | |||
561 | /** |
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562 | * Gets password requirements in the platform language using get_lang |
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563 | * based in platform settings. See function 'self::getPasswordRequirements'. |
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564 | * |
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565 | * @return string |
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566 | */ |
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567 | public static function getPasswordRequirementsToString($passedConditions = []) |
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568 | { |
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569 | $output = ''; |
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570 | $setting = self::getPasswordRequirements(); |
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571 | foreach ($setting as $type => $rules) { |
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572 | foreach ($rules as $rule => $parameter) { |
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573 | if (empty($parameter)) { |
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574 | continue; |
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575 | } |
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576 | $output .= sprintf( |
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577 | get_lang( |
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578 | 'NewPasswordRequirement'.ucfirst($type).'X'.ucfirst($rule) |
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579 | ), |
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580 | $parameter |
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581 | ); |
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582 | $output .= '<br />'; |
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583 | } |
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584 | } |
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585 | |||
586 | return $output; |
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587 | } |
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588 | |||
589 | /** |
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590 | * Sanitize a string, so it can be used in the exec() command without |
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591 | * "jail-breaking" to execute other commands. |
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592 | * |
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593 | * @param string $param The string to filter |
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594 | */ |
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595 | public static function sanitizeExecParam(string $param): string |
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596 | { |
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597 | $param = preg_replace('/[`;&|]/', '', $param); |
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598 | |||
599 | return escapeshellarg($param); |
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600 | } |
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601 | |||
602 | private static function generateSecTokenVariable(string $prefix = ''): string |
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609 | } |
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610 | } |
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611 |