1 files changed, 68 insertions, 0 deletions
diff --git a/lib/htmlpurifier/library/HTMLPurifier/URISchemeRegistry.php b/lib/htmlpurifier/library/HTMLPurifier/URISchemeRegistry.php
new file mode 100644
index 000000000..576bf7b6d
--- /dev/null
+++ b/lib/htmlpurifier/library/HTMLPurifier/URISchemeRegistry.php
@@ -0,0 +1,68 @@
+<?php
+
+/**
+ * Registry for retrieving specific URI scheme validator objects.
+ */
+class HTMLPurifier_URISchemeRegistry
+{
+
+    /**
+     * Retrieve sole instance of the registry.
+     * @param $prototype Optional prototype to overload sole instance with,
+     *                   or bool true to reset to default registry.
+     * @note Pass a registry object $prototype with a compatible interface and
+     *       the function will copy it and return it all further times.
+     */
+    public static function instance($prototype = null) {
+        static $instance = null;
+        if ($prototype !== null) {
+            $instance = $prototype;
+        } elseif ($instance === null || $prototype == true) {
+            $instance = new HTMLPurifier_URISchemeRegistry();
+        }
+        return $instance;
+    }
+
+    /**
+     * Cache of retrieved schemes.
+     */
+    protected $schemes = array();
+
+    /**
+     * Retrieves a scheme validator object
+     * @param $scheme String scheme name like http or mailto
+     * @param $config HTMLPurifier_Config object
+     * @param $config HTMLPurifier_Context object
+     */
+    public function getScheme($scheme, $config, $context) {
+        if (!$config) $config = HTMLPurifier_Config::createDefault();
+
+        // important, otherwise attacker could include arbitrary file
+        $allowed_schemes = $config->get('URI.AllowedSchemes');
+        if (!$config->get('URI.OverrideAllowedSchemes') &&
+            !isset($allowed_schemes[$scheme])
+        ) {
+            return;
+        }
+
+        if (isset($this->schemes[$scheme])) return $this->schemes[$scheme];
+        if (!isset($allowed_schemes[$scheme])) return;
+
+        $class = 'HTMLPurifier_URIScheme_' . $scheme;
+        if (!class_exists($class)) return;
+        $this->schemes[$scheme] = new $class();
+        return $this->schemes[$scheme];
+    }
+
+    /**
+     * Registers a custom scheme to the cache, bypassing reflection.
+     * @param $scheme Scheme name
+     * @param $scheme_obj HTMLPurifier_URIScheme object
+     */
+    public function register($scheme, $scheme_obj) {
+        $this->schemes[$scheme] = $scheme_obj;
+    }
+
+}
+
+// vim: et sw=4 sts=4