library/smarty/libs/sysplugins/smarty_security.php
changeset 0 4869aea77e21
new file mode 100644
--- /dev/null
+++ b/library/smarty/libs/sysplugins/smarty_security.php
@@ -0,0 +1,628 @@
+<?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 = null;
+    /**
+     * Cache for $template_dir lookup
+     *
+     * @var array
+     */
+    protected $_template_dir = null;
+    /**
+     * Cache for $config_dir lookup
+     *
+     * @var array
+     */
+    protected $_config_dir = null;
+    /**
+     * Cache for $secure_dir lookup
+     *
+     * @var array
+     */
+    protected $_secure_dir = null;
+    /**
+     * Cache for $php_resource_dir lookup
+     *
+     * @var array
+     */
+    protected $_php_resource_dir = null;
+    /**
+     * Cache for $trusted_dir lookup
+     *
+     * @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 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", $compiler->lex->taglineno);
+            }
+        } elseif (in_array($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", $compiler->lex->taglineno);
+        }
+
+        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", $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", $compiler->lex->taglineno);
+            }
+        } elseif (in_array($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", $compiler->lex->taglineno);
+        }
+
+        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 contant 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 $filepath
+     *
+     * @return boolean         true if directory is trusted
+     * @throws SmartyException if directory is not trusted
+     */
+    public function isTrustedResourceDir($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 lookup
+                $this->_resource_dir = array_merge($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 lookup
+                $this->_php_resource_dir = array_merge($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");
+    }
+
+    /**
+     * 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
+     *
+     * @param $template
+     */
+    public function exitTemplate($template) {
+        if ($this->max_template_nesting > 0) {
+            $this->_current_template_nesting--;
+        }
+    }
+}