From bcfbb8338c63718cd92c49b0c659333f9d6f0f46 Mon Sep 17 00:00:00 2001
From: "Edward Z. Yang" <ezyang@mit.edu>
Date: Sun, 10 Apr 2011 13:09:24 +0100
Subject: [PATCH] URI.Munge munges https to http URIs.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
---
 NEWS                                       |  2 ++
 library/HTMLPurifier/URIFilter/Munge.php   | 11 +++++++++--
 library/HTMLPurifier/URIScheme.php         |  6 ++++++
 library/HTMLPurifier/URIScheme/https.php   |  1 +
 tests/HTMLPurifier/URIFilter/MungeTest.php | 17 +++++++++++++++++
 5 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index a90f38b6..7d1e8a94 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 ==========================
 
 4.3.1, unknown release date
+# URI.Munge now munges URIs inside the same host that go from https
+  to http.  Reported by Neike Taika-Tessaro.
 - Color keywords are now case insensitive.  Thanks Yzmir Ramirez
   <yramirez-htmlpurifier@adicio.com> for reporting.
 
diff --git a/library/HTMLPurifier/URIFilter/Munge.php b/library/HTMLPurifier/URIFilter/Munge.php
index efa10a64..40d059b2 100644
--- a/library/HTMLPurifier/URIFilter/Munge.php
+++ b/library/HTMLPurifier/URIFilter/Munge.php
@@ -23,9 +23,16 @@ class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
         if (is_null($uri->host) || empty($scheme_obj->browsable)) {
             return true;
         }
+        $uri_definition = $config->getDefinition('URI');
         // don't redirect if target host is our host
-        if ($uri->host === $config->getDefinition('URI')->host) {
-            return true;
+        if ($uri->host === $uri_definition->host) {
+            // but do redirect if we're currently on a secure scheme,
+            // and the target scheme is insecure
+            $current_scheme_obj = HTMLPurifier_URISchemeRegistry::instance()->getScheme($uri_definition->defaultScheme, $config, $context);
+            if ($scheme_obj->secure || !$current_scheme_obj->secure) {
+                return true;
+            }
+            // target scheme was not secure, but we were secure
         }
 
         $this->makeReplace($uri, $config, $context);
diff --git a/library/HTMLPurifier/URIScheme.php b/library/HTMLPurifier/URIScheme.php
index 25eb8410..7be95814 100644
--- a/library/HTMLPurifier/URIScheme.php
+++ b/library/HTMLPurifier/URIScheme.php
@@ -20,6 +20,12 @@ abstract class HTMLPurifier_URIScheme
     public $browsable = false;
 
     /**
+     * Whether or not data transmitted over this scheme is encrypted.
+     * https is secure, http is not.
+     */
+    public $secure = false;
+
+    /**
      * Whether or not the URI always uses <hier_part>, resolves edge cases
      * with making relative URIs absolute
      */
diff --git a/library/HTMLPurifier/URIScheme/https.php b/library/HTMLPurifier/URIScheme/https.php
index 29e38091..159c2874 100644
--- a/library/HTMLPurifier/URIScheme/https.php
+++ b/library/HTMLPurifier/URIScheme/https.php
@@ -6,6 +6,7 @@
 class HTMLPurifier_URIScheme_https extends HTMLPurifier_URIScheme_http {
 
     public $default_port = 443;
+    public $secure = true;
 
 }
 
diff --git a/tests/HTMLPurifier/URIFilter/MungeTest.php b/tests/HTMLPurifier/URIFilter/MungeTest.php
index 09624b07..1acf11ea 100644
--- a/tests/HTMLPurifier/URIFilter/MungeTest.php
+++ b/tests/HTMLPurifier/URIFilter/MungeTest.php
@@ -117,6 +117,23 @@ class HTMLPurifier_URIFilter_MungeTest extends HTMLPurifier_URIFilterHarness
         $this->assertFiltering('http://example.com/foobar');
     }
 
+    function testMungeIgnoreSameDomainInsecureToSecure() {
+        $this->setMunge('http://example.com/%s');
+        $this->assertFiltering('https://example.com/foobar');
+    }
+
+    function testMungeIgnoreSameDomainSecureToSecure() {
+        $this->config->set('URI.Base', 'https://example.com');
+        $this->setMunge('http://example.com/%s');
+        $this->assertFiltering('https://example.com/foobar');
+    }
+
+    function testMungeSameDomainSecureToInsecure() {
+        $this->config->set('URI.Base', 'https://example.com');
+        $this->setMunge('/%s');
+        $this->assertFiltering('http://example.com/foobar', '/http%3A%2F%2Fexample.com%2Ffoobar');
+    }
+
     function testMungeIgnoresSourceHost() {
         $this->config->set('URI.Host', 'foo.example.com');
         $this->setMunge('http://example.com/%s');
-- 
2.11.4.GIT