Bug 1573145: Create ContentSecurityUtils.h/cpp and move AssertAboutPageHasCSP into it. r=jkt

Differential Revision: https://phabricator.services.mozilla.com/D41537

--HG--
extra : moz-landing-system : lando

dom/base/Document.cpp

@@ -137,6 +137,7 @@
 #include "nsAboutProtocolUtils.h"
 #include "nsCanvasFrame.h"
 #include "nsContentCID.h"
+#include "nsContentSecurityUtils.h"
 #include "nsError.h"
 #include "nsPresContext.h"
 #include "nsThreadUtils.h"
@@ -7147,80 +7148,6 @@ void Document::DispatchContentLoadedEvents() {
   UnblockOnload(true);
 }
 
-#if defined(DEBUG) && !defined(ANDROID)
-// We want to get to a point where all about: pages ship with a CSP. This
-// assertion ensures that we can not deploy new about: pages without a CSP.
-// Initially we will whitelist legacy about: pages which not yet have a CSP
-// attached, but ultimately that whitelist should disappear.
-// Please note that any about: page should not use inline JS or inline CSS,
-// and instead should load JS and CSS from an external file (*.js, *.css)
-// which allows us to apply a strong CSP omitting 'unsafe-inline'. Ideally,
-// the CSP allows precisely the resources that need to be loaded; but it
-// should at least be as strong as:
-// <meta http-equiv="Content-Security-Policy" content="default-src chrome:"/>
-static void AssertAboutPageHasCSP(Document* aDocument) {
-  // Check if we are loading an about: URI at all
-  nsCOMPtr<nsIURI> documentURI = aDocument->GetDocumentURI();
-  if (!documentURI->SchemeIs("about") ||
-      Preferences::GetBool("csp.skip_about_page_has_csp_assert")) {
-    return;
-  }
-
-  // Potentially init the legacy whitelist of about URIs without a CSP.
-  static StaticAutoPtr<nsTArray<nsCString>> sLegacyAboutPagesWithNoCSP;
-  if (!sLegacyAboutPagesWithNoCSP ||
-      Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
-    sLegacyAboutPagesWithNoCSP = new nsTArray<nsCString>();
-    nsAutoCString legacyAboutPages;
-    Preferences::GetCString("csp.about_uris_without_csp", legacyAboutPages);
-    for (const nsACString& hostString : legacyAboutPages.Split(',')) {
-      // please note that for the actual whitelist we only store the path of
-      // about: URI. Let's reassemble the full about URI here so we don't
-      // have to remove query arguments later.
-      nsCString aboutURI;
-      aboutURI.AppendLiteral("about:");
-      aboutURI.Append(hostString);
-      sLegacyAboutPagesWithNoCSP->AppendElement(aboutURI);
-    }
-    ClearOnShutdown(&sLegacyAboutPagesWithNoCSP);
-  }
-
-  // Check if the about URI is whitelisted
-  nsAutoCString aboutSpec;
-  documentURI->GetSpec(aboutSpec);
-  ToLowerCase(aboutSpec);
-  for (auto& legacyPageEntry : *sLegacyAboutPagesWithNoCSP) {
-    // please note that we perform a substring match here on purpose,
-    // so we don't have to deal and parse out all the query arguments
-    // the various about pages rely on.
-    if (aboutSpec.Find(legacyPageEntry) == 0) {
-      return;
-    }
-  }
-
-  nsCOMPtr<nsIContentSecurityPolicy> csp = aDocument->GetCsp();
-  bool foundDefaultSrc = false;
-  if (csp) {
-    uint32_t policyCount = 0;
-    csp->GetPolicyCount(&policyCount);
-    nsAutoString parsedPolicyStr;
-    for (uint32_t i = 0; i < policyCount; ++i) {
-      csp->GetPolicyString(i, parsedPolicyStr);
-      if (parsedPolicyStr.Find("default-src") >= 0) {
-        foundDefaultSrc = true;
-        break;
-      }
-    }
-  }
-  if (Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
-    NS_ASSERTION(foundDefaultSrc, "about: page must have a CSP");
-    return;
-  }
-  MOZ_ASSERT(foundDefaultSrc,
-             "about: page must contain a CSP including default-src");
-}
-#endif
-
 void Document::EndLoad() {
   bool turnOnEditing =
       mParser && (HasFlag(NODE_IS_EDITABLE) || mContentEditableCount > 0);
@@ -7228,7 +7155,7 @@ void Document::EndLoad() {
 #if defined(DEBUG) && !defined(ANDROID)
   // only assert if nothing stopped the load on purpose
   if (!mParserAborted) {
-    AssertAboutPageHasCSP(this);
+    nsContentSecurityUtils::AssertAboutPageHasCSP(this);
   }
 #endif
 

dom/security/moz.build

@@ -15,6 +15,7 @@ EXPORTS.mozilla.dom += [
     'CSPEvalChecker.h',
     'FramingChecker.h',
     'nsContentSecurityManager.h',
+    'nsContentSecurityUtils.h',
     'nsCSPContext.h',
     'nsCSPService.h',
     'nsCSPUtils.h',
@@ -28,6 +29,7 @@ EXPORTS.mozilla.dom += [
 
 EXPORTS += [
     'nsContentSecurityManager.h',
+    'nsContentSecurityUtils.h',
     'nsMixedContentBlocker.h',
     'ReferrerInfo.h',
 ]
@@ -36,6 +38,7 @@ UNIFIED_SOURCES += [
     'CSPEvalChecker.cpp',
     'FramingChecker.cpp',
     'nsContentSecurityManager.cpp',
+    'nsContentSecurityUtils.cpp',
     'nsCSPContext.cpp',
     'nsCSPParser.cpp',
     'nsCSPService.cpp',

dom/security/nsContentSecurityUtils.cpp

@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* A namespace class for static content security utilities. */
+
+#include "nsContentSecurityUtils.h"
+
+#include "nsIContentSecurityPolicy.h"
+#include "nsIURI.h"
+
+#include "mozilla/dom/Document.h"
+
+#if defined(DEBUG) && !defined(ANDROID)
+/* static */
+void nsContentSecurityUtils::AssertAboutPageHasCSP(Document* aDocument) {
+  // We want to get to a point where all about: pages ship with a CSP. This
+  // assertion ensures that we can not deploy new about: pages without a CSP.
+  // Initially we will whitelist legacy about: pages which not yet have a CSP
+  // attached, but ultimately that whitelist should disappear.
+  // Please note that any about: page should not use inline JS or inline CSS,
+  // and instead should load JS and CSS from an external file (*.js, *.css)
+  // which allows us to apply a strong CSP omitting 'unsafe-inline'. Ideally,
+  // the CSP allows precisely the resources that need to be loaded; but it
+  // should at least be as strong as:
+  // <meta http-equiv="Content-Security-Policy" content="default-src chrome:"/>
+
+  // Check if we are loading an about: URI at all
+  nsCOMPtr<nsIURI> documentURI = aDocument->GetDocumentURI();
+  if (!documentURI->SchemeIs("about") ||
+      Preferences::GetBool("csp.skip_about_page_has_csp_assert")) {
+    return;
+  }
+
+  // Potentially init the legacy whitelist of about URIs without a CSP.
+  static StaticAutoPtr<nsTArray<nsCString>> sLegacyAboutPagesWithNoCSP;
+  if (!sLegacyAboutPagesWithNoCSP ||
+      Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
+    sLegacyAboutPagesWithNoCSP = new nsTArray<nsCString>();
+    nsAutoCString legacyAboutPages;
+    Preferences::GetCString("csp.about_uris_without_csp", legacyAboutPages);
+    for (const nsACString& hostString : legacyAboutPages.Split(',')) {
+      // please note that for the actual whitelist we only store the path of
+      // about: URI. Let's reassemble the full about URI here so we don't
+      // have to remove query arguments later.
+      nsCString aboutURI;
+      aboutURI.AppendLiteral("about:");
+      aboutURI.Append(hostString);
+      sLegacyAboutPagesWithNoCSP->AppendElement(aboutURI);
+    }
+    ClearOnShutdown(&sLegacyAboutPagesWithNoCSP);
+  }
+
+  // Check if the about URI is whitelisted
+  nsAutoCString aboutSpec;
+  documentURI->GetSpec(aboutSpec);
+  ToLowerCase(aboutSpec);
+  for (auto& legacyPageEntry : *sLegacyAboutPagesWithNoCSP) {
+    // please note that we perform a substring match here on purpose,
+    // so we don't have to deal and parse out all the query arguments
+    // the various about pages rely on.
+    if (aboutSpec.Find(legacyPageEntry) == 0) {
+      return;
+    }
+  }
+
+  nsCOMPtr<nsIContentSecurityPolicy> csp = aDocument->GetCsp();
+  bool foundDefaultSrc = false;
+  if (csp) {
+    uint32_t policyCount = 0;
+    csp->GetPolicyCount(&policyCount);
+    nsAutoString parsedPolicyStr;
+    for (uint32_t i = 0; i < policyCount; ++i) {
+      csp->GetPolicyString(i, parsedPolicyStr);
+      if (parsedPolicyStr.Find("default-src") >= 0) {
+        foundDefaultSrc = true;
+        break;
+      }
+    }
+  }
+  if (Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
+    NS_ASSERTION(foundDefaultSrc, "about: page must have a CSP");
+    return;
+  }
+  MOZ_ASSERT(foundDefaultSrc,
+             "about: page must contain a CSP including default-src");
+}
+#endif

dom/security/nsContentSecurityUtils.h

@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* A namespace class for static content security utilities. */
+
+#ifndef nsContentSecurityUtils_h___
+#define nsContentSecurityUtils_h___
+
+namespace mozilla {
+namespace dom {
+class Document;
+}  // namespace dom
+}  // namespace mozilla
+
+class nsContentSecurityUtils {
+ public:
+#if defined(DEBUG) && !defined(ANDROID)
+  static void AssertAboutPageHasCSP(Document* aDocument);
+#endif
+};
+
+#endif /* nsContentSecurityUtils_h___ */