diff options
Diffstat (limited to 'lib/smarty3/sysplugins/smarty_security.php')
| -rw-r--r-- | lib/smarty3/sysplugins/smarty_security.php | 730 |
1 files changed, 730 insertions, 0 deletions
diff --git a/lib/smarty3/sysplugins/smarty_security.php b/lib/smarty3/sysplugins/smarty_security.php new file mode 100644 index 0000000..f2f98f4 --- /dev/null +++ b/lib/smarty3/sysplugins/smarty_security.php @@ -0,0 +1,730 @@ +<?php +/** + * Smarty plugin + * + * @package Smarty + * @subpackage Security + * @author Uwe Tews + */ + +/* + * FIXME: Smarty_Security API + * - getter and setter instead of public properties would allow cultivating an internal cache properly + * - current implementation of isTrustedResourceDir() assumes that Smarty::$template_dir and Smarty::$config_dir are immutable + * the cache is killed every time either of the variables change. That means that two distinct Smarty objects with differing + * $template_dir or $config_dir should NOT share the same Smarty_Security instance, + * as this would lead to (severe) performance penalty! how should this be handled? + */ + +/** + * This class does contain the security settings + */ +class Smarty_Security +{ + /** + * This determines how Smarty handles "<?php ... ?>" tags in templates. + * possible values: + * <ul> + * <li>Smarty::PHP_PASSTHRU -> echo PHP tags as they are</li> + * <li>Smarty::PHP_QUOTE -> escape tags as entities</li> + * <li>Smarty::PHP_REMOVE -> remove php tags</li> + * <li>Smarty::PHP_ALLOW -> execute php tags</li> + * </ul> + * + * @var integer + */ + public $php_handling = Smarty::PHP_PASSTHRU; + + /** + * This is the list of template directories that are considered secure. + * $template_dir is in this list implicitly. + * + * @var array + */ + public $secure_dir = array(); + + /** + * This is an array of directories where trusted php scripts reside. + * {@link $security} is disabled during their inclusion/execution. + * + * @var array + */ + public $trusted_dir = array(); + + /** + * List of regular expressions (PCRE) that include trusted URIs + * + * @var array + */ + public $trusted_uri = array(); + + /** + * List of trusted constants names + * + * @var array + */ + public $trusted_constants = array(); + + /** + * This is an array of trusted static classes. + * If empty access to all static classes is allowed. + * If set to 'none' none is allowed. + * + * @var array + */ + public $static_classes = array(); + + /** + * This is an nested array of trusted classes and static methods. + * If empty access to all static classes and methods is allowed. + * Format: + * array ( + * 'class_1' => array('method_1', 'method_2'), // allowed methods listed + * 'class_2' => array(), // all methods of class allowed + * ) + * If set to null none is allowed. + * + * @var array + */ + public $trusted_static_methods = array(); + + /** + * This is an array of trusted static properties. + * If empty access to all static classes and properties is allowed. + * Format: + * array ( + * 'class_1' => array('prop_1', 'prop_2'), // allowed properties listed + * 'class_2' => array(), // all properties of class allowed + * ) + * If set to null none is allowed. + * + * @var array + */ + public $trusted_static_properties = array(); + + /** + * This is an array of trusted PHP functions. + * If empty all functions are allowed. + * To disable all PHP functions set $php_functions = null. + * + * @var array + */ + public $php_functions = array('isset', 'empty', 'count', 'sizeof', 'in_array', 'is_array', 'time',); + + /** + * This is an array of trusted PHP modifiers. + * If empty all modifiers are allowed. + * To disable all modifier set $php_modifiers = null. + * + * @var array + */ + public $php_modifiers = array('escape', 'count', 'nl2br',); + + /** + * This is an array of allowed tags. + * If empty no restriction by allowed_tags. + * + * @var array + */ + public $allowed_tags = array(); + + /** + * This is an array of disabled tags. + * If empty no restriction by disabled_tags. + * + * @var array + */ + public $disabled_tags = array(); + + /** + * This is an array of allowed modifier plugins. + * If empty no restriction by allowed_modifiers. + * + * @var array + */ + public $allowed_modifiers = array(); + + /** + * This is an array of disabled modifier plugins. + * If empty no restriction by disabled_modifiers. + * + * @var array + */ + public $disabled_modifiers = array(); + + /** + * This is an array of disabled special $smarty variables. + * + * @var array + */ + public $disabled_special_smarty_vars = array(); + + /** + * This is an array of trusted streams. + * If empty all streams are allowed. + * To disable all streams set $streams = null. + * + * @var array + */ + public $streams = array('file'); + + /** + * + flag if constants can be accessed from template + * + * @var boolean + */ + public $allow_constants = true; + + /** + * + flag if super globals can be accessed from template + * + * @var boolean + */ + public $allow_super_globals = true; + + /** + * max template nesting level + * + * @var int + */ + public $max_template_nesting = 0; + + /** + * current template nesting level + * + * @var int + */ + private $_current_template_nesting = 0; + + /** + * Cache for $resource_dir lookup + * + * @var array + */ + protected $_resource_dir = array(); + + /** + * Cache for $template_dir lookup + * + * @var array + */ + protected $_template_dir = array(); + + /** + * Cache for $config_dir lookup + * + * @var array + */ + protected $_config_dir = array(); + + /** + * Cache for $secure_dir lookup + * + * @var array + */ + protected $_secure_dir = array(); + + /** + * Cache for $php_resource_dir lookup + * + * @var array + */ + protected $_php_resource_dir = null; + + /** + * Cache for $trusted_dir lookup + * + * @var array + */ + protected $_trusted_dir = null; + + /** + * Cache for include path status + * + * @var bool + */ + protected $_include_path_status = false; + + /** + * Cache for $_include_array lookup + * + * @var array + */ + protected $_include_dir = array(); + + /** + * @param Smarty $smarty + */ + public function __construct($smarty) + { + $this->smarty = $smarty; + $this->smarty->_cache[ 'template_dir_new' ] = true; + $this->smarty->_cache[ 'config_dir_new' ] = true; + } + + /** + * Check if PHP function is trusted. + * + * @param string $function_name + * @param object $compiler compiler object + * + * @return boolean true if function is trusted + * @throws SmartyCompilerException if php function is not trusted + */ + public function isTrustedPhpFunction($function_name, $compiler) + { + if (isset($this->php_functions) && + (empty($this->php_functions) || in_array($function_name, $this->php_functions)) + ) { + return true; + } + + $compiler->trigger_template_error("PHP function '{$function_name}' not allowed by security setting"); + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if static class is trusted. + * + * @param string $class_name + * @param object $compiler compiler object + * + * @return boolean true if class is trusted + * @throws SmartyCompilerException if static class is not trusted + */ + public function isTrustedStaticClass($class_name, $compiler) + { + if (isset($this->static_classes) && + (empty($this->static_classes) || in_array($class_name, $this->static_classes)) + ) { + return true; + } + + $compiler->trigger_template_error("access to static class '{$class_name}' not allowed by security setting"); + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if static class method/property is trusted. + * + * @param string $class_name + * @param string $params + * @param object $compiler compiler object + * + * @return boolean true if class method is trusted + * @throws SmartyCompilerException if static class method is not trusted + */ + public function isTrustedStaticClassAccess($class_name, $params, $compiler) + { + if (!isset($params[ 2 ])) { + // fall back + return $this->isTrustedStaticClass($class_name, $compiler); + } + if ($params[ 2 ] == 'method') { + $allowed = $this->trusted_static_methods; + $name = substr($params[ 0 ], 0, strpos($params[ 0 ], '(')); + } else { + $allowed = $this->trusted_static_properties; + // strip '$' + $name = substr($params[ 0 ], 1); + } + if (isset($allowed)) { + if (empty($allowed)) { + // fall back + return $this->isTrustedStaticClass($class_name, $compiler); + } + if (isset($allowed[ $class_name ]) && + (empty($allowed[ $class_name ]) || in_array($name, $allowed[ $class_name ])) + ) { + return true; + } + } + $compiler->trigger_template_error("access to static class '{$class_name}' {$params[2]} '{$name}' not allowed by security setting"); + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if PHP modifier is trusted. + * + * @param string $modifier_name + * @param object $compiler compiler object + * + * @return boolean true if modifier is trusted + * @throws SmartyCompilerException if modifier is not trusted + */ + public function isTrustedPhpModifier($modifier_name, $compiler) + { + if (isset($this->php_modifiers) && + (empty($this->php_modifiers) || in_array($modifier_name, $this->php_modifiers)) + ) { + return true; + } + + $compiler->trigger_template_error("modifier '{$modifier_name}' not allowed by security setting"); + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if tag is trusted. + * + * @param string $tag_name + * @param object $compiler compiler object + * + * @return boolean true if tag is trusted + * @throws SmartyCompilerException if modifier is not trusted + */ + public function isTrustedTag($tag_name, $compiler) + { + // check for internal always required tags + if (in_array($tag_name, + array('assign', 'call', 'private_filter', 'private_block_plugin', 'private_function_plugin', + 'private_object_block_function', 'private_object_function', 'private_registered_function', + 'private_registered_block', 'private_special_variable', 'private_print_expression', + 'private_modifier'))) { + return true; + } + // check security settings + if (empty($this->allowed_tags)) { + if (empty($this->disabled_tags) || !in_array($tag_name, $this->disabled_tags)) { + return true; + } else { + $compiler->trigger_template_error("tag '{$tag_name}' disabled by security setting", null, true); + } + } elseif (in_array($tag_name, $this->allowed_tags) && !in_array($tag_name, $this->disabled_tags)) { + return true; + } else { + $compiler->trigger_template_error("tag '{$tag_name}' not allowed by security setting", null, true); + } + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if special $smarty variable is trusted. + * + * @param string $var_name + * @param object $compiler compiler object + * + * @return boolean true if tag is trusted + * @throws SmartyCompilerException if modifier is not trusted + */ + public function isTrustedSpecialSmartyVar($var_name, $compiler) + { + if (!in_array($var_name, $this->disabled_special_smarty_vars)) { + return true; + } else { + $compiler->trigger_template_error("special variable '\$smarty.{$var_name}' not allowed by security setting", + null, true); + } + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if modifier plugin is trusted. + * + * @param string $modifier_name + * @param object $compiler compiler object + * + * @return boolean true if tag is trusted + * @throws SmartyCompilerException if modifier is not trusted + */ + public function isTrustedModifier($modifier_name, $compiler) + { + // check for internal always allowed modifier + if (in_array($modifier_name, array('default'))) { + return true; + } + // check security settings + if (empty($this->allowed_modifiers)) { + if (empty($this->disabled_modifiers) || !in_array($modifier_name, $this->disabled_modifiers)) { + return true; + } else { + $compiler->trigger_template_error("modifier '{$modifier_name}' disabled by security setting", null, + true); + } + } elseif (in_array($modifier_name, $this->allowed_modifiers) && + !in_array($modifier_name, $this->disabled_modifiers) + ) { + return true; + } else { + $compiler->trigger_template_error("modifier '{$modifier_name}' not allowed by security setting", null, + true); + } + + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * Check if constants are enabled or trusted + * + * @param string $const constant name + * @param object $compiler compiler object + * + * @return bool + */ + public function isTrustedConstant($const, $compiler) + { + if (in_array($const, array('true', 'false', 'null'))) { + return true; + } + if (!empty($this->trusted_constants)) { + if (!in_array($const, $this->trusted_constants)) { + $compiler->trigger_template_error("Security: access to constant '{$const}' not permitted"); + return false; + } + return true; + } + if ($this->allow_constants) { + return true; + } + $compiler->trigger_template_error("Security: access to constants not permitted"); + return false; + } + + /** + * Check if stream is trusted. + * + * @param string $stream_name + * + * @return boolean true if stream is trusted + * @throws SmartyException if stream is not trusted + */ + public function isTrustedStream($stream_name) + { + if (isset($this->streams) && (empty($this->streams) || in_array($stream_name, $this->streams))) { + return true; + } + + throw new SmartyException("stream '{$stream_name}' not allowed by security setting"); + } + + /** + * Check if directory of file resource is trusted. + * + * @param string $filepath + * @param null|bool $isConfig + * + * @return bool true if directory is trusted + * @throws \SmartyException if directory is not trusted + */ + public function isTrustedResourceDir($filepath, $isConfig = null) + { + if ($this->_include_path_status !== $this->smarty->use_include_path) { + foreach ($this->_include_dir as $directory) { + unset($this->_resource_dir[ $directory ]); + } + if ($this->smarty->use_include_path) { + $this->_include_dir = array(); + $_dirs = $this->smarty->ext->_getIncludePath->getIncludePathDirs($this->smarty); + foreach ($_dirs as $directory) { + $this->_include_dir[] = $directory; + $this->_resource_dir[ $directory ] = true; + } + } + $this->_include_path_status = $this->smarty->use_include_path; + } + if ($isConfig !== true && + (!isset($this->smarty->_cache[ 'template_dir_new' ]) || $this->smarty->_cache[ 'template_dir_new' ]) + ) { + $_dir = $this->smarty->getTemplateDir(); + if ($this->_template_dir !== $_dir) { + foreach ($this->_template_dir as $directory) { + unset($this->_resource_dir[ $directory ]); + } + foreach ($_dir as $directory) { + $this->_resource_dir[ $directory ] = true; + } + $this->_template_dir = $_dir; + } + $this->smarty->_cache[ 'template_dir_new' ] = false; + } + if ($isConfig !== false && + (!isset($this->smarty->_cache[ 'config_dir_new' ]) || $this->smarty->_cache[ 'config_dir_new' ]) + ) { + $_dir = $this->smarty->getConfigDir(); + if ($this->_config_dir !== $_dir) { + foreach ($this->_config_dir as $directory) { + unset($this->_resource_dir[ $directory ]); + } + foreach ($_dir as $directory) { + $this->_resource_dir[ $directory ] = true; + } + $this->_config_dir = $_dir; + } + $this->smarty->_cache[ 'config_dir_new' ] = false; + } + if ($this->_secure_dir !== (array) $this->secure_dir) { + foreach ($this->_secure_dir as $directory) { + unset($this->_resource_dir[ $directory ]); + } + foreach ((array) $this->secure_dir as $directory) { + $directory = $this->smarty->_realpath($directory . DS, true); + $this->_resource_dir[ $directory ] = true; + } + $this->_secure_dir = (array) $this->secure_dir; + } + $this->_resource_dir = $this->_checkDir($filepath, $this->_resource_dir); + return true; + } + + /** + * Check if URI (e.g. {fetch} or {html_image}) is trusted + * To simplify things, isTrustedUri() resolves all input to "{$PROTOCOL}://{$HOSTNAME}". + * So "http://username:password@hello.world.example.org:8080/some-path?some=query-string" + * is reduced to "http://hello.world.example.org" prior to applying the patters from {@link $trusted_uri}. + * + * @param string $uri + * + * @return boolean true if URI is trusted + * @throws SmartyException if URI is not trusted + * @uses $trusted_uri for list of patterns to match against $uri + */ + public function isTrustedUri($uri) + { + $_uri = parse_url($uri); + if (!empty($_uri[ 'scheme' ]) && !empty($_uri[ 'host' ])) { + $_uri = $_uri[ 'scheme' ] . '://' . $_uri[ 'host' ]; + foreach ($this->trusted_uri as $pattern) { + if (preg_match($pattern, $_uri)) { + return true; + } + } + } + + throw new SmartyException("URI '{$uri}' not allowed by security setting"); + } + + /** + * Check if directory of file resource is trusted. + * + * @param string $filepath + * + * @return boolean true if directory is trusted + * @throws SmartyException if PHP directory is not trusted + */ + public function isTrustedPHPDir($filepath) + { + if (empty($this->trusted_dir)) { + throw new SmartyException("directory '{$filepath}' not allowed by security setting (no trusted_dir specified)"); + } + + // check if index is outdated + if (!$this->_trusted_dir || $this->_trusted_dir !== $this->trusted_dir) { + $this->_php_resource_dir = array(); + + $this->_trusted_dir = $this->trusted_dir; + foreach ((array) $this->trusted_dir as $directory) { + $directory = $this->smarty->_realpath($directory . DS, true); + $this->_php_resource_dir[ $directory ] = true; + } + } + + $this->_php_resource_dir = + $this->_checkDir($this->smarty->_realpath($filepath, true), $this->_php_resource_dir); + return true; + } + + /** + * Check if file is inside a valid directory + * + * @param string $filepath + * @param array $dirs valid directories + * + * @return array + * @throws \SmartyException + */ + private function _checkDir($filepath, $dirs) + { + $directory = dirname($filepath) . DS; + $_directory = array(); + while (true) { + // remember the directory to add it to _resource_dir in case we're successful + $_directory[ $directory ] = true; + // test if the directory is trusted + if (isset($dirs[ $directory ])) { + // merge sub directories of current $directory into _resource_dir to speed up subsequent lookup + $dirs = array_merge($dirs, $_directory); + + return $dirs; + } + // abort if we've reached root + if (!preg_match('#[\\\/][^\\\/]+[\\\/]$#', $directory)) { + break; + } + // bubble up one level + $directory = preg_replace('#[\\\/][^\\\/]+[\\\/]$#', DS, $directory); + } + + // give up + throw new SmartyException("directory '{$filepath}' not allowed by security setting"); + } + + /** + * Loads security class and enables security + * + * @param \Smarty $smarty + * @param string|Smarty_Security $security_class if a string is used, it must be class-name + * + * @return \Smarty current Smarty instance for chaining + * @throws \SmartyException when an invalid class name is provided + */ + public static function enableSecurity(Smarty $smarty, $security_class) + { + if ($security_class instanceof Smarty_Security) { + $smarty->security_policy = $security_class; + return; + } elseif (is_object($security_class)) { + throw new SmartyException("Class '" . get_class($security_class) . "' must extend Smarty_Security."); + } + if ($security_class == null) { + $security_class = $smarty->security_class; + } + if (!class_exists($security_class)) { + throw new SmartyException("Security class '$security_class' is not defined"); + } elseif ($security_class !== 'Smarty_Security' && !is_subclass_of($security_class, 'Smarty_Security')) { + throw new SmartyException("Class '$security_class' must extend Smarty_Security."); + } else { + $smarty->security_policy = new $security_class($smarty); + } + return; + } + /** + * Start template processing + * + * @param $template + * + * @throws SmartyException + */ + public function startTemplate($template) + { + if ($this->max_template_nesting > 0 && $this->_current_template_nesting ++ >= $this->max_template_nesting) { + throw new SmartyException("maximum template nesting level of '{$this->max_template_nesting}' exceeded when calling '{$template->template_resource}'"); + } + } + + /** + * Exit template processing + * + */ + public function endTemplate() + { + if ($this->max_template_nesting > 0) { + $this->_current_template_nesting --; + } + } + + /** + * Register callback functions call at start/end of template rendering + * + * @param \Smarty_Internal_Template $template + */ + public function registerCallBacks(Smarty_Internal_Template $template) + { + $template->startRenderCallbacks[] = array($this, 'startTemplate'); + $template->endRenderCallbacks[] = array($this, 'endTemplate'); + } +} |