1 files changed, 74 insertions, 17 deletions

diff --git a/library/HTMLPurifier/URIFilter/Munge.php b/library/HTMLPurifier/URIFilter/Munge.php
index efa10a645..6e03315a1 100644
--- a/library/HTMLPurifier/URIFilter/Munge.php
+++ b/library/HTMLPurifier/URIFilter/Munge.php
@@ -2,31 +2,79 @@
 
 class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
 {
+    /**
+     * @type string
+     */
     public $name = 'Munge';
+
+    /**
+     * @type bool
+     */
     public $post = true;
-    private $target, $parser, $doEmbed, $secretKey;
 
+    /**
+     * @type string
+     */
+    private $target;
+
+    /**
+     * @type HTMLPurifier_URIParser
+     */
+    private $parser;
+
+    /**
+     * @type bool
+     */
+    private $doEmbed;
+
+    /**
+     * @type string
+     */
+    private $secretKey;
+
+    /**
+     * @type array
+     */
     protected $replace = array();
 
-    public function prepare($config) {
-        $this->target    = $config->get('URI.' . $this->name);
-        $this->parser    = new HTMLPurifier_URIParser();
-        $this->doEmbed   = $config->get('URI.MungeResources');
+    /**
+     * @param HTMLPurifier_Config $config
+     * @return bool
+     */
+    public function prepare($config)
+    {
+        $this->target = $config->get('URI.' . $this->name);
+        $this->parser = new HTMLPurifier_URIParser();
+        $this->doEmbed = $config->get('URI.MungeResources');
         $this->secretKey = $config->get('URI.MungeSecretKey');
+        if ($this->secretKey && !function_exists('hash_hmac')) {
+            throw new Exception("Cannot use %URI.MungeSecretKey without hash_hmac support.");
+        }
         return true;
     }
-    public function filter(&$uri, $config, $context) {
-        if ($context->get('EmbeddedURI', true) && !$this->doEmbed) return true;
 
-        $scheme_obj = $uri->getSchemeObj($config, $context);
-        if (!$scheme_obj) return true; // ignore unknown schemes, maybe another postfilter did it
-        if (is_null($uri->host) || empty($scheme_obj->browsable)) {
+    /**
+     * @param HTMLPurifier_URI $uri
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool
+     */
+    public function filter(&$uri, $config, $context)
+    {
+        if ($context->get('EmbeddedURI', true) && !$this->doEmbed) {
             return true;
         }
-        // don't redirect if target host is our host
-        if ($uri->host === $config->getDefinition('URI')->host) {
+
+        $scheme_obj = $uri->getSchemeObj($config, $context);
+        if (!$scheme_obj) {
             return true;
-        }
+        } // ignore unknown schemes, maybe another postfilter did it
+        if (!$scheme_obj->browsable) {
+            return true;
+        } // ignore non-browseable schemes, since we can't munge those in a reasonable way
+        if ($uri->isBenign($config, $context)) {
+            return true;
+        } // don't redirect if a benign URL
 
         $this->makeReplace($uri, $config, $context);
         $this->replace = array_map('rawurlencode', $this->replace);
@@ -35,12 +83,20 @@ class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
         $new_uri = $this->parser->parse($new_uri);
         // don't redirect if the target host is the same as the
         // starting host
-        if ($uri->host === $new_uri->host) return true;
+        if ($uri->host === $new_uri->host) {
+            return true;
+        }
         $uri = $new_uri; // overwrite
         return true;
     }
 
-    protected function makeReplace($uri, $config, $context) {
+    /**
+     * @param HTMLPurifier_URI $uri
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     */
+    protected function makeReplace($uri, $config, $context)
+    {
         $string = $uri->toString();
         // always available
         $this->replace['%s'] = $string;
@@ -50,9 +106,10 @@ class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
         $this->replace['%m'] = $context->get('CurrentAttr', true);
         $this->replace['%p'] = $context->get('CurrentCSSProperty', true);
         // not always available
-        if ($this->secretKey) $this->replace['%t'] = sha1($this->secretKey . ':' . $string);
+        if ($this->secretKey) {
+            $this->replace['%t'] = hash_hmac("sha256", $string, $this->secretKey);
+        }
     }
-
 }
 
 // vim: et sw=4 sts=4