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1 <?php |
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2 /** |
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3 * Smarty plugin |
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4 * |
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5 * @package Smarty |
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6 * @subpackage Security |
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7 * @author Uwe Tews |
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8 */ |
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9 |
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10 /* |
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11 * FIXME: Smarty_Security API |
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12 * - getter and setter instead of public properties would allow cultivating an internal cache properly |
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13 * - current implementation of isTrustedResourceDir() assumes that Smarty::$template_dir and Smarty::$config_dir are immutable |
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14 * the cache is killed every time either of the variables change. That means that two distinct Smarty objects with differing |
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15 * $template_dir or $config_dir should NOT share the same Smarty_Security instance, |
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16 * as this would lead to (severe) performance penalty! how should this be handled? |
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17 */ |
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18 |
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19 /** |
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20 * This class does contain the security settings |
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21 */ |
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22 class Smarty_Security { |
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23 |
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24 /** |
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25 * This determines how Smarty handles "<?php ... ?>" tags in templates. |
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26 * possible values: |
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27 * <ul> |
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28 * <li>Smarty::PHP_PASSTHRU -> echo PHP tags as they are</li> |
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29 * <li>Smarty::PHP_QUOTE -> escape tags as entities</li> |
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30 * <li>Smarty::PHP_REMOVE -> remove php tags</li> |
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31 * <li>Smarty::PHP_ALLOW -> execute php tags</li> |
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32 * </ul> |
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33 * |
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34 * @var integer |
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35 */ |
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36 public $php_handling = Smarty::PHP_PASSTHRU; |
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37 /** |
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38 * This is the list of template directories that are considered secure. |
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39 * $template_dir is in this list implicitly. |
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40 * |
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41 * @var array |
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42 */ |
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43 public $secure_dir = array(); |
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44 /** |
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45 * This is an array of directories where trusted php scripts reside. |
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46 * {@link $security} is disabled during their inclusion/execution. |
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47 * |
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48 * @var array |
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49 */ |
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50 public $trusted_dir = array(); |
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51 /** |
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52 * List of regular expressions (PCRE) that include trusted URIs |
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53 * |
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54 * @var array |
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55 */ |
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56 public $trusted_uri = array(); |
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57 /** |
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58 * This is an array of trusted static classes. |
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59 * |
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60 * If empty access to all static classes is allowed. |
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61 * If set to 'none' none is allowed. |
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62 * @var array |
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63 */ |
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64 public $static_classes = array(); |
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65 /** |
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66 * This is an array of trusted PHP functions. |
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67 * |
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68 * If empty all functions are allowed. |
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69 * To disable all PHP functions set $php_functions = null. |
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70 * @var array |
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71 */ |
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72 public $php_functions = array( |
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73 'isset', 'empty', |
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74 'count', 'sizeof', |
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75 'in_array', 'is_array', |
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76 'time', |
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77 'nl2br', |
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78 ); |
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79 /** |
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80 * This is an array of trusted PHP modifers. |
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81 * |
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82 * If empty all modifiers are allowed. |
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83 * To disable all modifier set $modifiers = null. |
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84 * @var array |
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85 */ |
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86 public $php_modifiers = array( |
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87 'escape', |
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88 'count' |
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89 ); |
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90 /** |
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91 * This is an array of allowed tags. |
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92 * |
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93 * If empty no restriction by allowed_tags. |
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94 * @var array |
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95 */ |
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96 public $allowed_tags = array(); |
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97 /** |
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98 * This is an array of disabled tags. |
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99 * |
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100 * If empty no restriction by disabled_tags. |
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101 * @var array |
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102 */ |
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103 public $disabled_tags = array(); |
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104 /** |
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105 * This is an array of allowed modifier plugins. |
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106 * |
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107 * If empty no restriction by allowed_modifiers. |
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108 * @var array |
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109 */ |
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110 public $allowed_modifiers = array(); |
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111 /** |
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112 * This is an array of disabled modifier plugins. |
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113 * |
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114 * If empty no restriction by disabled_modifiers. |
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115 * @var array |
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116 */ |
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117 public $disabled_modifiers = array(); |
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118 /** |
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119 * This is an array of trusted streams. |
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120 * |
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121 * If empty all streams are allowed. |
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122 * To disable all streams set $streams = null. |
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123 * @var array |
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124 */ |
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125 public $streams = array('file'); |
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126 /** |
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127 * + flag if constants can be accessed from template |
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128 * @var boolean |
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129 */ |
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130 public $allow_constants = true; |
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131 /** |
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132 * + flag if super globals can be accessed from template |
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133 * @var boolean |
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134 */ |
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135 public $allow_super_globals = true; |
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136 |
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137 /** |
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138 * Cache for $resource_dir lookups |
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139 * @var array |
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140 */ |
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141 protected $_resource_dir = null; |
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142 /** |
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143 * Cache for $template_dir lookups |
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144 * @var array |
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145 */ |
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146 protected $_template_dir = null; |
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147 /** |
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148 * Cache for $config_dir lookups |
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149 * @var array |
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150 */ |
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151 protected $_config_dir = null; |
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152 /** |
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153 * Cache for $secure_dir lookups |
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154 * @var array |
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155 */ |
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156 protected $_secure_dir = null; |
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157 /** |
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158 * Cache for $php_resource_dir lookups |
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159 * @var array |
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160 */ |
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161 protected $_php_resource_dir = null; |
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162 /** |
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163 * Cache for $trusted_dir lookups |
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164 * @var array |
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165 */ |
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166 protected $_trusted_dir = null; |
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167 |
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168 |
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169 /** |
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170 * @param Smarty $smarty |
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171 */ |
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172 public function __construct($smarty) |
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173 { |
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174 $this->smarty = $smarty; |
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175 } |
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176 |
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177 /** |
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178 * Check if PHP function is trusted. |
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179 * |
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180 * @param string $function_name |
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181 * @param object $compiler compiler object |
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182 * @return boolean true if function is trusted |
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183 * @throws SmartyCompilerException if php function is not trusted |
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184 */ |
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185 public function isTrustedPhpFunction($function_name, $compiler) |
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186 { |
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187 if (isset($this->php_functions) && (empty($this->php_functions) || in_array($function_name, $this->php_functions))) { |
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188 return true; |
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189 } |
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190 |
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191 $compiler->trigger_template_error("PHP function '{$function_name}' not allowed by security setting"); |
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192 return false; // should not, but who knows what happens to the compiler in the future? |
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193 } |
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194 |
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195 /** |
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196 * Check if static class is trusted. |
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197 * |
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198 * @param string $class_name |
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199 * @param object $compiler compiler object |
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200 * @return boolean true if class is trusted |
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201 * @throws SmartyCompilerException if static class is not trusted |
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202 */ |
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203 public function isTrustedStaticClass($class_name, $compiler) |
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204 { |
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205 if (isset($this->static_classes) && (empty($this->static_classes) || in_array($class_name, $this->static_classes))) { |
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206 return true; |
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207 } |
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208 |
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209 $compiler->trigger_template_error("access to static class '{$class_name}' not allowed by security setting"); |
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210 return false; // should not, but who knows what happens to the compiler in the future? |
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211 } |
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212 |
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213 /** |
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214 * Check if PHP modifier is trusted. |
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215 * |
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216 * @param string $modifier_name |
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217 * @param object $compiler compiler object |
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218 * @return boolean true if modifier is trusted |
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219 * @throws SmartyCompilerException if modifier is not trusted |
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220 */ |
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221 public function isTrustedPhpModifier($modifier_name, $compiler) |
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222 { |
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223 if (isset($this->php_modifiers) && (empty($this->php_modifiers) || in_array($modifier_name, $this->php_modifiers))) { |
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224 return true; |
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225 } |
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226 |
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227 $compiler->trigger_template_error("modifier '{$modifier_name}' not allowed by security setting"); |
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228 return false; // should not, but who knows what happens to the compiler in the future? |
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229 } |
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230 |
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231 /** |
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232 * Check if tag is trusted. |
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233 * |
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234 * @param string $tag_name |
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235 * @param object $compiler compiler object |
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236 * @return boolean true if tag is trusted |
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237 * @throws SmartyCompilerException if modifier is not trusted |
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238 */ |
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239 public function isTrustedTag($tag_name, $compiler) |
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240 { |
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241 // check for internal always required tags |
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242 if (in_array($tag_name, array('assign', 'call', 'private_filter', 'private_block_plugin', 'private_function_plugin', 'private_object_block_function', |
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243 'private_object_function', 'private_registered_function', 'private_registered_block', 'private_special_variable', 'private_print_expression', 'private_modifier'))) { |
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244 return true; |
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245 } |
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246 // check security settings |
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247 if (empty($this->allowed_tags)) { |
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248 if (empty($this->disabled_tags) || !in_array($tag_name, $this->disabled_tags)) { |
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249 return true; |
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250 } else { |
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251 $compiler->trigger_template_error("tag '{$tag_name}' disabled by security setting", $compiler->lex->taglineno); |
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252 } |
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253 } else if (in_array($tag_name, $this->allowed_tags) && !in_array($tag_name, $this->disabled_tags)) { |
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254 return true; |
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255 } else { |
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256 $compiler->trigger_template_error("tag '{$tag_name}' not allowed by security setting", $compiler->lex->taglineno); |
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257 } |
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258 return false; // should not, but who knows what happens to the compiler in the future? |
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259 } |
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260 |
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261 /** |
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262 * Check if modifier plugin is trusted. |
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263 * |
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264 * @param string $modifier_name |
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265 * @param object $compiler compiler object |
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266 * @return boolean true if tag is trusted |
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267 * @throws SmartyCompilerException if modifier is not trusted |
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268 */ |
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269 public function isTrustedModifier($modifier_name, $compiler) |
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270 { |
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271 // check for internal always allowed modifier |
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272 if (in_array($modifier_name, array('default'))) { |
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273 return true; |
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274 } |
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275 // check security settings |
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276 if (empty($this->allowed_modifiers)) { |
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277 if (empty($this->disabled_modifiers) || !in_array($modifier_name, $this->disabled_modifiers)) { |
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278 return true; |
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279 } else { |
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280 $compiler->trigger_template_error("modifier '{$modifier_name}' disabled by security setting", $compiler->lex->taglineno); |
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281 } |
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282 } else if (in_array($modifier_name, $this->allowed_modifiers) && !in_array($modifier_name, $this->disabled_modifiers)) { |
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283 return true; |
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284 } else { |
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285 $compiler->trigger_template_error("modifier '{$modifier_name}' not allowed by security setting", $compiler->lex->taglineno); |
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286 } |
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287 return false; // should not, but who knows what happens to the compiler in the future? |
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288 } |
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289 |
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290 /** |
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291 * Check if stream is trusted. |
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292 * |
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293 * @param string $stream_name |
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294 * @return boolean true if stream is trusted |
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295 * @throws SmartyException if stream is not trusted |
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296 */ |
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297 public function isTrustedStream($stream_name) |
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298 { |
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299 if (isset($this->streams) && (empty($this->streams) || in_array($stream_name, $this->streams))) { |
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300 return true; |
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301 } |
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302 |
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303 throw new SmartyException("stream '{$stream_name}' not allowed by security setting"); |
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304 } |
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305 |
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306 /** |
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307 * Check if directory of file resource is trusted. |
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308 * |
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309 * @param string $filepath |
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310 * @return boolean true if directory is trusted |
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311 * @throws SmartyException if directory is not trusted |
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312 */ |
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313 public function isTrustedResourceDir($filepath) |
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314 { |
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315 $_template = false; |
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316 $_config = false; |
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317 $_secure = false; |
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318 |
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319 $_template_dir = $this->smarty->getTemplateDir(); |
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320 $_config_dir = $this->smarty->getConfigDir(); |
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321 |
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322 // check if index is outdated |
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323 if ((!$this->_template_dir || $this->_template_dir !== $_template_dir) |
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324 || (!$this->_config_dir || $this->_config_dir !== $_config_dir) |
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325 || (!empty($this->secure_dir) && (!$this->_secure_dir || $this->_secure_dir !== $this->secure_dir)) |
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326 ) { |
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327 $this->_resource_dir = array(); |
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328 $_template = true; |
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329 $_config = true; |
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330 $_secure = !empty($this->secure_dir); |
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331 } |
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332 |
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333 // rebuild template dir index |
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334 if ($_template) { |
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335 $this->_template_dir = $_template_dir; |
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336 foreach ($_template_dir as $directory) { |
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337 $directory = realpath($directory); |
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338 $this->_resource_dir[$directory] = true; |
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339 } |
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340 } |
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341 |
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342 // rebuild config dir index |
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343 if ($_config) { |
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344 $this->_config_dir = $_config_dir; |
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345 foreach ($_config_dir as $directory) { |
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346 $directory = realpath($directory); |
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347 $this->_resource_dir[$directory] = true; |
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348 } |
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349 } |
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350 |
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351 // rebuild secure dir index |
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352 if ($_secure) { |
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353 $this->_secure_dir = $this->secure_dir; |
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354 foreach ((array) $this->secure_dir as $directory) { |
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355 $directory = realpath($directory); |
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356 $this->_resource_dir[$directory] = true; |
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357 } |
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358 } |
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359 |
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360 $_filepath = realpath($filepath); |
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361 $directory = dirname($_filepath); |
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362 $_directory = array(); |
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363 while (true) { |
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364 // remember the directory to add it to _resource_dir in case we're successful |
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365 $_directory[$directory] = true; |
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366 // test if the directory is trusted |
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367 if (isset($this->_resource_dir[$directory])) { |
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368 // merge sub directories of current $directory into _resource_dir to speed up subsequent lookups |
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369 $this->_resource_dir = array_merge($this->_resource_dir, $_directory); |
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370 return true; |
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371 } |
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372 // abort if we've reached root |
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373 if (($pos = strrpos($directory, DS)) === false || !isset($directory[1])) { |
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374 break; |
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375 } |
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376 // bubble up one level |
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377 $directory = substr($directory, 0, $pos); |
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378 } |
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379 |
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380 // give up |
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381 throw new SmartyException("directory '{$_filepath}' not allowed by security setting"); |
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382 } |
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383 |
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384 /** |
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385 * Check if URI (e.g. {fetch} or {html_image}) is trusted |
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386 * |
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387 * To simplify things, isTrustedUri() resolves all input to "{$PROTOCOL}://{$HOSTNAME}". |
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388 * So "http://username:password@hello.world.example.org:8080/some-path?some=query-string" |
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389 * is reduced to "http://hello.world.example.org" prior to applying the patters from {@link $trusted_uri}. |
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390 * @param string $uri |
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391 * @return boolean true if URI is trusted |
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392 * @throws SmartyException if URI is not trusted |
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393 * @uses $trusted_uri for list of patterns to match against $uri |
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394 */ |
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395 public function isTrustedUri($uri) |
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396 { |
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397 $_uri = parse_url($uri); |
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398 if (!empty($_uri['scheme']) && !empty($_uri['host'])) { |
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399 $_uri = $_uri['scheme'] . '://' . $_uri['host']; |
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400 foreach ($this->trusted_uri as $pattern) { |
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401 if (preg_match($pattern, $_uri)) { |
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402 return true; |
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403 } |
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404 } |
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405 } |
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406 |
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407 throw new SmartyException("URI '{$uri}' not allowed by security setting"); |
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408 } |
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409 |
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410 /** |
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411 * Check if directory of file resource is trusted. |
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412 * |
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413 * @param string $filepath |
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414 * @return boolean true if directory is trusted |
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415 * @throws SmartyException if PHP directory is not trusted |
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416 */ |
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417 public function isTrustedPHPDir($filepath) |
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418 { |
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419 if (empty($this->trusted_dir)) { |
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420 throw new SmartyException("directory '{$filepath}' not allowed by security setting (no trusted_dir specified)"); |
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421 } |
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422 |
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423 // check if index is outdated |
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424 if (!$this->_trusted_dir || $this->_trusted_dir !== $this->trusted_dir) { |
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425 $this->_php_resource_dir = array(); |
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426 |
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427 $this->_trusted_dir = $this->trusted_dir; |
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428 foreach ((array) $this->trusted_dir as $directory) { |
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429 $directory = realpath($directory); |
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430 $this->_php_resource_dir[$directory] = true; |
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431 } |
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432 } |
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433 |
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434 $_filepath = realpath($filepath); |
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435 $directory = dirname($_filepath); |
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436 $_directory = array(); |
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437 while (true) { |
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438 // remember the directory to add it to _resource_dir in case we're successful |
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439 $_directory[] = $directory; |
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440 // test if the directory is trusted |
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441 if (isset($this->_php_resource_dir[$directory])) { |
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442 // merge sub directories of current $directory into _resource_dir to speed up subsequent lookups |
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443 $this->_php_resource_dir = array_merge($this->_php_resource_dir, $_directory); |
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444 return true; |
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445 } |
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446 // abort if we've reached root |
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447 if (($pos = strrpos($directory, DS)) === false || !isset($directory[2])) { |
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448 break; |
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449 } |
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450 // bubble up one level |
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451 $directory = substr($directory, 0, $pos); |
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452 } |
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453 |
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454 throw new SmartyException("directory '{$_filepath}' not allowed by security setting"); |
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455 } |
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456 |
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457 } |
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458 |
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459 ?> |