1 files changed, 56 insertions, 0 deletions
diff --git a/lib/htmlpurifier/library/HTMLPurifier/AttrDef/CSS/URI.php b/lib/htmlpurifier/library/HTMLPurifier/AttrDef/CSS/URI.php
new file mode 100755
index 000000000..435d7930b
--- /dev/null
+++ b/lib/htmlpurifier/library/HTMLPurifier/AttrDef/CSS/URI.php
@@ -0,0 +1,56 @@
+<?php
+
+/**
+ * Validates a URI in CSS syntax, which uses url('http://example.com')
+ * @note While theoretically speaking a URI in a CSS document could
+ *       be non-embedded, as of CSS2 there is no such usage so we're
+ *       generalizing it. This may need to be changed in the future.
+ * @warning Since HTMLPurifier_AttrDef_CSS blindly uses semicolons as
+ *          the separator, you cannot put a literal semicolon in
+ *          in the URI. Try percent encoding it, in that case.
+ */
+class HTMLPurifier_AttrDef_CSS_URI extends HTMLPurifier_AttrDef_URI
+{
+
+    public function __construct() {
+        parent::__construct(true); // always embedded
+    }
+
+    public function validate($uri_string, $config, $context) {
+        // parse the URI out of the string and then pass it onto
+        // the parent object
+
+        $uri_string = $this->parseCDATA($uri_string);
+        if (strpos($uri_string, 'url(') !== 0) return false;
+        $uri_string = substr($uri_string, 4);
+        $new_length = strlen($uri_string) - 1;
+        if ($uri_string[$new_length] != ')') return false;
+        $uri = trim(substr($uri_string, 0, $new_length));
+
+        if (!empty($uri) && ($uri[0] == "'" || $uri[0] == '"')) {
+            $quote = $uri[0];
+            $new_length = strlen($uri) - 1;
+            if ($uri[$new_length] !== $quote) return false;
+            $uri = substr($uri, 1, $new_length - 1);
+        }
+
+        $keys   = array(  '(',   ')',   ',',   ' ',   '"',   "'");
+        $values = array('\\(', '\\)', '\\,', '\\ ', '\\"', "\\'");
+        $uri = str_replace($values, $keys, $uri);
+
+        $result = parent::validate($uri, $config, $context);
+
+        if ($result === false) return false;
+
+        // escape necessary characters according to CSS spec
+        // except for the comma, none of these should appear in the
+        // URI at all
+        $result = str_replace($keys, $values, $result);
+
+        return "url($result)";
+
+    }
+
+}
+
+// vim: et sw=4 sts=4