htmlpurifier update - compatibility issue with language library autoloader

1 files changed, 199 insertions, 58 deletions

diff --git a/library/HTMLPurifier/URI.php b/library/HTMLPurifier/URI.php
index 8b50d0d18..a5e7ae298 100644
--- a/library/HTMLPurifier/URI.php
+++ b/library/HTMLPurifier/URI.php
@@ -10,17 +10,57 @@
  */
 class HTMLPurifier_URI
 {
+    /**
+     * @type string
+     */
+    public $scheme;
 
-    public $scheme, $userinfo, $host, $port, $path, $query, $fragment;
+    /**
+     * @type string
+     */
+    public $userinfo;
 
     /**
+     * @type string
+     */
+    public $host;
+
+    /**
+     * @type int
+     */
+    public $port;
+
+    /**
+     * @type string
+     */
+    public $path;
+
+    /**
+     * @type string
+     */
+    public $query;
+
+    /**
+     * @type string
+     */
+    public $fragment;
+
+    /**
+     * @param string $scheme
+     * @param string $userinfo
+     * @param string $host
+     * @param int $port
+     * @param string $path
+     * @param string $query
+     * @param string $fragment
      * @note Automatically normalizes scheme and port
      */
-    public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment) {
+    public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment)
+    {
         $this->scheme = is_null($scheme) || ctype_lower($scheme) ? $scheme : strtolower($scheme);
         $this->userinfo = $userinfo;
         $this->host = $host;
-        $this->port = is_null($port) ? $port : (int) $port;
+        $this->port = is_null($port) ? $port : (int)$port;
         $this->path = $path;
         $this->query = $query;
         $this->fragment = $fragment;
@@ -28,19 +68,22 @@ class HTMLPurifier_URI
 
     /**
      * Retrieves a scheme object corresponding to the URI's scheme/default
-     * @param $config Instance of HTMLPurifier_Config
-     * @param $context Instance of HTMLPurifier_Context
-     * @return Scheme object appropriate for validating this URI
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return HTMLPurifier_URIScheme Scheme object appropriate for validating this URI
      */
-    public function getSchemeObj($config, $context) {
+    public function getSchemeObj($config, $context)
+    {
         $registry = HTMLPurifier_URISchemeRegistry::instance();
         if ($this->scheme !== null) {
             $scheme_obj = $registry->getScheme($this->scheme, $config, $context);
-            if (!$scheme_obj) return false; // invalid scheme, clean it out
+            if (!$scheme_obj) {
+                return false;
+            } // invalid scheme, clean it out
         } else {
             // no scheme: retrieve the default one
             $def = $config->getDefinition('URI');
-            $scheme_obj = $registry->getScheme($def->defaultScheme, $config, $context);
+            $scheme_obj = $def->getDefaultScheme($config, $context);
             if (!$scheme_obj) {
                 // something funky happened to the default scheme object
                 trigger_error(
@@ -56,30 +99,39 @@ class HTMLPurifier_URI
     /**
      * Generic validation method applicable for all schemes. May modify
      * this URI in order to get it into a compliant form.
-     * @param $config Instance of HTMLPurifier_Config
-     * @param $context Instance of HTMLPurifier_Context
-     * @return True if validation/filtering succeeds, false if failure
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool True if validation/filtering succeeds, false if failure
      */
-    public function validate($config, $context) {
-
+    public function validate($config, $context)
+    {
         // ABNF definitions from RFC 3986
         $chars_sub_delims = '!$&\'()*+,;=';
         $chars_gen_delims = ':/?#[]@';
         $chars_pchar = $chars_sub_delims . ':@';
 
-        // validate scheme (MUST BE FIRST!)
-        if (!is_null($this->scheme) && is_null($this->host)) {
-            $def = $config->getDefinition('URI');
-            if ($def->defaultScheme === $this->scheme) {
-                $this->scheme = null;
-            }
-        }
-
         // validate host
         if (!is_null($this->host)) {
             $host_def = new HTMLPurifier_AttrDef_URI_Host();
             $this->host = $host_def->validate($this->host, $config, $context);
-            if ($this->host === false) $this->host = null;
+            if ($this->host === false) {
+                $this->host = null;
+            }
+        }
+
+        // validate scheme
+        // NOTE: It's not appropriate to check whether or not this
+        // scheme is in our registry, since a URIFilter may convert a
+        // URI that we don't allow into one we do.  So instead, we just
+        // check if the scheme can be dropped because there is no host
+        // and it is our default scheme.
+        if (!is_null($this->scheme) && is_null($this->host) || $this->host === '') {
+            // support for relative paths is pretty abysmal when the
+            // scheme is present, so axe it when possible
+            $def = $config->getDefinition('URI');
+            if ($def->defaultScheme === $this->scheme) {
+                $this->scheme = null;
+            }
         }
 
         // validate username
@@ -90,38 +142,55 @@ class HTMLPurifier_URI
 
         // validate port
         if (!is_null($this->port)) {
-            if ($this->port < 1 || $this->port > 65535) $this->port = null;
+            if ($this->port < 1 || $this->port > 65535) {
+                $this->port = null;
+            }
         }
 
         // validate path
-        $path_parts = array();
         $segments_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/');
-        if (!is_null($this->host)) {
+        if (!is_null($this->host)) { // this catches $this->host === ''
             // path-abempty (hier and relative)
+            // http://www.example.com/my/path
+            // //www.example.com/my/path (looks odd, but works, and
+            //                            recognized by most browsers)
+            // (this set is valid or invalid on a scheme by scheme
+            // basis, so we'll deal with it later)
+            // file:///my/path
+            // ///my/path
             $this->path = $segments_encoder->encode($this->path);
-        } elseif ($this->path !== '' && $this->path[0] === '/') {
-            // path-absolute (hier and relative)
-            if (strlen($this->path) >= 2 && $this->path[1] === '/') {
-                // This shouldn't ever happen!
-                $this->path = '';
-            } else {
+        } elseif ($this->path !== '') {
+            if ($this->path[0] === '/') {
+                // path-absolute (hier and relative)
+                // http:/my/path
+                // /my/path
+                if (strlen($this->path) >= 2 && $this->path[1] === '/') {
+                    // This could happen if both the host gets stripped
+                    // out
+                    // http://my/path
+                    // //my/path
+                    $this->path = '';
+                } else {
+                    $this->path = $segments_encoder->encode($this->path);
+                }
+            } elseif (!is_null($this->scheme)) {
+                // path-rootless (hier)
+                // http:my/path
+                // Short circuit evaluation means we don't need to check nz
                 $this->path = $segments_encoder->encode($this->path);
-            }
-        } elseif (!is_null($this->scheme) && $this->path !== '') {
-            // path-rootless (hier)
-            // Short circuit evaluation means we don't need to check nz
-            $this->path = $segments_encoder->encode($this->path);
-        } elseif (is_null($this->scheme) && $this->path !== '') {
-            // path-noscheme (relative)
-            // (once again, not checking nz)
-            $segment_nc_encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . '@');
-            $c = strpos($this->path, '/');
-            if ($c !== false) {
-                $this->path =
-                    $segment_nc_encoder->encode(substr($this->path, 0, $c)) .
-                    $segments_encoder->encode(substr($this->path, $c));
             } else {
-                $this->path = $segment_nc_encoder->encode($this->path);
+                // path-noscheme (relative)
+                // my/path
+                // (once again, not checking nz)
+                $segment_nc_encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . '@');
+                $c = strpos($this->path, '/');
+                if ($c !== false) {
+                    $this->path =
+                        $segment_nc_encoder->encode(substr($this->path, 0, $c)) .
+                        $segments_encoder->encode(substr($this->path, $c));
+                } else {
+                    $this->path = $segment_nc_encoder->encode($this->path);
+                }
             }
         } else {
             // path-empty (hier and relative)
@@ -138,36 +207,108 @@ class HTMLPurifier_URI
         if (!is_null($this->fragment)) {
             $this->fragment = $qf_encoder->encode($this->fragment);
         }
-
         return true;
-
     }
 
     /**
      * Convert URI back to string
-     * @return String URI appropriate for output
+     * @return string URI appropriate for output
      */
-    public function toString() {
+    public function toString()
+    {
         // reconstruct authority
         $authority = null;
+        // there is a rendering difference between a null authority
+        // (http:foo-bar) and an empty string authority
+        // (http:///foo-bar).
         if (!is_null($this->host)) {
             $authority = '';
-            if(!is_null($this->userinfo)) $authority .= $this->userinfo . '@';
+            if (!is_null($this->userinfo)) {
+                $authority .= $this->userinfo . '@';
+            }
             $authority .= $this->host;
-            if(!is_null($this->port))     $authority .= ':' . $this->port;
+            if (!is_null($this->port)) {
+                $authority .= ':' . $this->port;
+            }
         }
 
-        // reconstruct the result
+        // Reconstruct the result
+        // One might wonder about parsing quirks from browsers after
+        // this reconstruction.  Unfortunately, parsing behavior depends
+        // on what *scheme* was employed (file:///foo is handled *very*
+        // differently than http:///foo), so unfortunately we have to
+        // defer to the schemes to do the right thing.
         $result = '';
-        if (!is_null($this->scheme))    $result .= $this->scheme . ':';
-        if (!is_null($authority))       $result .=  '//' . $authority;
+        if (!is_null($this->scheme)) {
+            $result .= $this->scheme . ':';
+        }
+        if (!is_null($authority)) {
+            $result .= '//' . $authority;
+        }
         $result .= $this->path;
-        if (!is_null($this->query))     $result .= '?' . $this->query;
-        if (!is_null($this->fragment))  $result .= '#' . $this->fragment;
+        if (!is_null($this->query)) {
+            $result .= '?' . $this->query;
+        }
+        if (!is_null($this->fragment)) {
+            $result .= '#' . $this->fragment;
+        }
 
         return $result;
     }
 
+    /**
+     * Returns true if this URL might be considered a 'local' URL given
+     * the current context.  This is true when the host is null, or
+     * when it matches the host supplied to the configuration.
+     *
+     * Note that this does not do any scheme checking, so it is mostly
+     * only appropriate for metadata that doesn't care about protocol
+     * security.  isBenign is probably what you actually want.
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool
+     */
+    public function isLocal($config, $context)
+    {
+        if ($this->host === null) {
+            return true;
+        }
+        $uri_def = $config->getDefinition('URI');
+        if ($uri_def->host === $this->host) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Returns true if this URL should be considered a 'benign' URL,
+     * that is:
+     *
+     *      - It is a local URL (isLocal), and
+     *      - It has a equal or better level of security
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool
+     */
+    public function isBenign($config, $context)
+    {
+        if (!$this->isLocal($config, $context)) {
+            return false;
+        }
+
+        $scheme_obj = $this->getSchemeObj($config, $context);
+        if (!$scheme_obj) {
+            return false;
+        } // conservative approach
+
+        $current_scheme_obj = $config->getDefinition('URI')->getDefaultScheme($config, $context);
+        if ($current_scheme_obj->secure) {
+            if (!$scheme_obj->secure) {
+                return false;
+            }
+        }
+        return true;
+    }
 }
 
 // vim: et sw=4 sts=4