diff options
Diffstat (limited to 'include/smarty/libs/sysplugins/smarty_security.php')
| -rw-r--r-- | include/smarty/libs/sysplugins/smarty_security.php | 459 |
1 files changed, 459 insertions, 0 deletions
diff --git a/include/smarty/libs/sysplugins/smarty_security.php b/include/smarty/libs/sysplugins/smarty_security.php new file mode 100644 index 000000000..f8b31d963 --- /dev/null +++ b/include/smarty/libs/sysplugins/smarty_security.php @@ -0,0 +1,459 @@ +<?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(); + /** + * 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 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', + 'nl2br', + ); + /** + * This is an array of trusted PHP modifers. + * + * If empty all modifiers are allowed. + * To disable all modifier set $modifiers = null. + * @var array + */ + public $php_modifiers = array( + 'escape', + 'count' + ); + /** + * 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 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; + + /** + * Cache for $resource_dir lookups + * @var array + */ + protected $_resource_dir = null; + /** + * Cache for $template_dir lookups + * @var array + */ + protected $_template_dir = null; + /** + * Cache for $config_dir lookups + * @var array + */ + protected $_config_dir = null; + /** + * Cache for $secure_dir lookups + * @var array + */ + protected $_secure_dir = null; + /** + * Cache for $php_resource_dir lookups + * @var array + */ + protected $_php_resource_dir = null; + /** + * Cache for $trusted_dir lookups + * @var array + */ + protected $_trusted_dir = null; + + + /** + * @param Smarty $smarty + */ + public function __construct($smarty) + { + $this->smarty = $smarty; + } + + /** + * 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 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", $compiler->lex->taglineno); + } + } else if (in_array($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", $compiler->lex->taglineno); + } + 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", $compiler->lex->taglineno); + } + } else if (in_array($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", $compiler->lex->taglineno); + } + return false; // should not, but who knows what happens to the compiler in the future? + } + + /** + * 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 $filepath + * @return boolean true if directory is trusted + * @throws SmartyException if directory is not trusted + */ + public function isTrustedResourceDir($filepath) + { + $_template = false; + $_config = false; + $_secure = false; + + $_template_dir = $this->smarty->getTemplateDir(); + $_config_dir = $this->smarty->getConfigDir(); + + // check if index is outdated + if ((!$this->_template_dir || $this->_template_dir !== $_template_dir) + || (!$this->_config_dir || $this->_config_dir !== $_config_dir) + || (!empty($this->secure_dir) && (!$this->_secure_dir || $this->_secure_dir !== $this->secure_dir)) + ) { + $this->_resource_dir = array(); + $_template = true; + $_config = true; + $_secure = !empty($this->secure_dir); + } + + // rebuild template dir index + if ($_template) { + $this->_template_dir = $_template_dir; + foreach ($_template_dir as $directory) { + $directory = realpath($directory); + $this->_resource_dir[$directory] = true; + } + } + + // rebuild config dir index + if ($_config) { + $this->_config_dir = $_config_dir; + foreach ($_config_dir as $directory) { + $directory = realpath($directory); + $this->_resource_dir[$directory] = true; + } + } + + // rebuild secure dir index + if ($_secure) { + $this->_secure_dir = $this->secure_dir; + foreach ((array) $this->secure_dir as $directory) { + $directory = realpath($directory); + $this->_resource_dir[$directory] = true; + } + } + + $_filepath = realpath($filepath); + $directory = dirname($_filepath); + $_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($this->_resource_dir[$directory])) { + // merge sub directories of current $directory into _resource_dir to speed up subsequent lookups + $this->_resource_dir = array_merge($this->_resource_dir, $_directory); + return true; + } + // abort if we've reached root + if (($pos = strrpos($directory, DS)) === false || !isset($directory[1])) { + break; + } + // bubble up one level + $directory = substr($directory, 0, $pos); + } + + // give up + throw new SmartyException("directory '{$_filepath}' not allowed by security setting"); + } + + /** + * 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) { + $directory = realpath($directory); + $this->_php_resource_dir[$directory] = true; + } + } + + $_filepath = realpath($filepath); + $directory = dirname($_filepath); + $_directory = array(); + while (true) { + // remember the directory to add it to _resource_dir in case we're successful + $_directory[] = $directory; + // test if the directory is trusted + if (isset($this->_php_resource_dir[$directory])) { + // merge sub directories of current $directory into _resource_dir to speed up subsequent lookups + $this->_php_resource_dir = array_merge($this->_php_resource_dir, $_directory); + return true; + } + // abort if we've reached root + if (($pos = strrpos($directory, DS)) === false || !isset($directory[2])) { + break; + } + // bubble up one level + $directory = substr($directory, 0, $pos); + } + + throw new SmartyException("directory '{$_filepath}' not allowed by security setting"); + } + +} + +?>
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