From 6b4d81521f0c7bef48a1e8c3e9254a81df27a9d2 Mon Sep 17 00:00:00 2001
From: wolfbeast <mcwerewolf@wolfbeast.com>
Date: Sat, 9 Mar 2019 08:15:36 +0100
Subject: Prevent loading of document subresources over FTP.

---
 .../en-US/chrome/security/security.properties      |  2 +
 dom/security/nsContentSecurityManager.cpp          | 56 ++++++++++++++++++++++
 dom/security/nsContentSecurityManager.h            |  1 +
 3 files changed, 59 insertions(+)

(limited to 'dom')

diff --git a/dom/locales/en-US/chrome/security/security.properties b/dom/locales/en-US/chrome/security/security.properties
index 8efdb0a6d..2be56fb9d 100644
--- a/dom/locales/en-US/chrome/security/security.properties
+++ b/dom/locales/en-US/chrome/security/security.properties
@@ -85,3 +85,5 @@ BlockScriptWithWrongMimeType=Script from “%1$S” was blocked because of a dis
 
 # LOCALIZATION NOTE: Do not translate "data: URI".
 BlockTopLevelDataURINavigation=Navigation to toplevel data: URI not allowed (Blocked loading of: “%1$S”)
+
+BlockSubresourceFTP=Loading FTP subresource within http(s) page not allowed (Blocked loading of: “%1$S”)
diff --git a/dom/security/nsContentSecurityManager.cpp b/dom/security/nsContentSecurityManager.cpp
index 570730312..f2cbc8fcf 100644
--- a/dom/security/nsContentSecurityManager.cpp
+++ b/dom/security/nsContentSecurityManager.cpp
@@ -92,6 +92,55 @@ nsContentSecurityManager::AllowTopLevelNavigationToDataURI(nsIChannel* aChannel)
   return false;
 }
 
+/* static */ nsresult
+nsContentSecurityManager::CheckFTPSubresourceLoad(nsIChannel* aChannel)
+{
+  // We dissallow using FTP resources as a subresource everywhere.
+  // The only valid way to use FTP resources is loading it as
+  // a top level document.
+
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
+  if (!loadInfo) {
+    return NS_OK;
+  }
+
+  nsContentPolicyType type = loadInfo->GetExternalContentPolicyType();
+  if (type == nsIContentPolicy::TYPE_DOCUMENT) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, rv); 
+  if (!uri) {
+    return NS_OK;
+  }
+
+  bool isFtpURI = (NS_SUCCEEDED(uri->SchemeIs("ftp", &isFtpURI)) && isFtpURI);
+  if (!isFtpURI) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDocument> doc;
+  if (nsINode* node = loadInfo->LoadingNode()) {
+    doc = node->OwnerDoc();
+  }
+
+  nsAutoCString spec;
+  uri->GetSpec(spec);
+  NS_ConvertUTF8toUTF16 specUTF16(NS_UnescapeURL(spec));
+  const char16_t* params[] = { specUTF16.get() };
+
+  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                  NS_LITERAL_CSTRING("FTP_URI_BLOCKED"),
+                                  doc,
+                                  nsContentUtils::eSECURITY_PROPERTIES,
+                                  "BlockSubresourceFTP",
+                                  params, ArrayLength(params));
+
+  return NS_ERROR_CONTENT_BLOCKED;
+}
+
 static nsresult
 ValidateSecurityFlags(nsILoadInfo* aLoadInfo)
 {
@@ -574,6 +623,10 @@ nsContentSecurityManager::doContentSecurityCheck(nsIChannel* aChannel,
   rv = DoContentSecurityChecks(aChannel, loadInfo);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  // Apply this after CSP checks to allow CSP reporting.
+  rv = CheckFTPSubresourceLoad(aChannel);
+  NS_ENSURE_SUCCESS(rv, rv);
+
   // now lets set the initalSecurityFlag for subsequent calls
   loadInfo->SetInitialSecurityCheckDone(true);
 
@@ -591,6 +644,9 @@ nsContentSecurityManager::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
   // Are we enforcing security using LoadInfo?
   if (loadInfo && loadInfo->GetEnforceSecurity()) {
     nsresult rv = CheckChannel(aNewChannel);
+    if (NS_SUCCEEDED(rv)) {
+      rv = CheckFTPSubresourceLoad(aNewChannel);
+    }
     if (NS_FAILED(rv)) {
       aOldChannel->Cancel(rv);
       return rv;
diff --git a/dom/security/nsContentSecurityManager.h b/dom/security/nsContentSecurityManager.h
index bab847743..750dd8803 100644
--- a/dom/security/nsContentSecurityManager.h
+++ b/dom/security/nsContentSecurityManager.h
@@ -36,6 +36,7 @@ public:
 
 private:
   static nsresult CheckChannel(nsIChannel* aChannel);
+  static nsresult CheckFTPSubresourceLoad(nsIChannel* aChannel);
 
   virtual ~nsContentSecurityManager() {}
 
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