Escape story fields and clean story HTML with HTML Purifier.

Add HTML Purifier 4.19.1. Stories are purified when they are saved and
when they are shown.

lib/htmlpurifier-4.19.1/library/HTMLPurifier.kses.php

@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * @file
+ * Emulation layer for code that used kses(), substituting in HTML Purifier.
+ */
+
+require_once dirname(__FILE__) . '/HTMLPurifier.auto.php';
+
+function kses($string, $allowed_html, $allowed_protocols = null)
+{
+    $config = HTMLPurifier_Config::createDefault();
+    $allowed_elements = array();
+    $allowed_attributes = array();
+    foreach ($allowed_html as $element => $attributes) {
+        $allowed_elements[$element] = true;
+        foreach ($attributes as $attribute => $x) {
+            $allowed_attributes["$element.$attribute"] = true;
+        }
+    }
+    $config->set('HTML.AllowedElements', $allowed_elements);
+    $config->set('HTML.AllowedAttributes', $allowed_attributes);
+    if ($allowed_protocols !== null) {
+        $config->set('URI.AllowedSchemes', $allowed_protocols);
+    }
+    $purifier = new HTMLPurifier($config);
+    return $purifier->purify($string);
+}
+
+// vim: et sw=4 sts=4