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-rw-r--r--dom/security/FramingChecker.cpp231
1 files changed, 231 insertions, 0 deletions
diff --git a/dom/security/FramingChecker.cpp b/dom/security/FramingChecker.cpp
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+++ b/dom/security/FramingChecker.cpp
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+/* -*- 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/. */
+
+#include "FramingChecker.h"
+#include "nsCharSeparatedTokenizer.h"
+#include "nsContentUtils.h"
+#include "nsCSPUtils.h"
+#include "nsDocShell.h"
+#include "nsHttpChannel.h"
+#include "nsContentSecurityUtils.h"
+#include "nsGlobalWindowOuter.h"
+#include "nsIChannel.h"
+#include "nsIConsoleReportCollector.h"
+#include "nsIContentSecurityPolicy.h"
+#include "nsIScriptError.h"
+#include "nsNetUtil.h"
+#include "nsQueryObject.h"
+#include "nsTArray.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/dom/nsCSPUtils.h"
+#include "mozilla/dom/LoadURIOptionsBinding.h"
+#include "mozilla/dom/WindowGlobalParent.h"
+#include "mozilla/NullPrincipal.h"
+#include "mozilla/net/HttpBaseChannel.h"
+
+#include "nsIObserverService.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+/* static */
+void FramingChecker::ReportError(const char* aMessageTag,
+ nsIHttpChannel* aChannel, nsIURI* aURI,
+ const nsAString& aPolicy) {
+ MOZ_ASSERT(aChannel);
+ MOZ_ASSERT(aURI);
+
+ nsCOMPtr<net::HttpBaseChannel> httpChannel = do_QueryInterface(aChannel);
+ if (!httpChannel) {
+ return;
+ }
+
+ // Get the URL spec
+ nsAutoCString spec;
+ nsresult rv = aURI->GetAsciiSpec(spec);
+ if (NS_FAILED(rv)) {
+ return;
+ }
+
+ nsTArray<nsString> params;
+ params.AppendElement(aPolicy);
+ params.AppendElement(NS_ConvertUTF8toUTF16(spec));
+
+ httpChannel->AddConsoleReport(nsIScriptError::errorFlag, "X-Frame-Options"_ns,
+ nsContentUtils::eSECURITY_PROPERTIES, spec, 0,
+ 0, nsDependentCString(aMessageTag), params);
+}
+
+/* static */
+bool FramingChecker::CheckOneFrameOptionsPolicy(nsIHttpChannel* aHttpChannel,
+ const nsAString& aPolicy) {
+ nsCOMPtr<nsIURI> uri;
+ aHttpChannel->GetURI(getter_AddRefs(uri));
+
+ // return early if header does not have one of the values with meaning
+ if (!aPolicy.LowerCaseEqualsLiteral("deny") &&
+ !aPolicy.LowerCaseEqualsLiteral("sameorigin")) {
+ ReportError("XFrameOptionsInvalid", aHttpChannel, uri, aPolicy);
+ return true;
+ }
+
+ // If the X-Frame-Options value is SAMEORIGIN, then the top frame in the
+ // parent chain must be from the same origin as this document.
+ bool checkSameOrigin = aPolicy.LowerCaseEqualsLiteral("sameorigin");
+
+ nsCOMPtr<nsILoadInfo> loadInfo = aHttpChannel->LoadInfo();
+ RefPtr<mozilla::dom::BrowsingContext> ctx;
+ loadInfo->GetBrowsingContext(getter_AddRefs(ctx));
+
+ while (ctx) {
+ nsCOMPtr<nsIPrincipal> principal;
+ // Generally CheckOneFrameOptionsPolicy is consulted from within the
+ // DocumentLoadListener in the parent process. For loads of type object
+ // and embed it's called from the Document in the content process.
+ // After Bug 1646899 we should be able to remove that branching code for
+ // querying the principal.
+ if (XRE_IsParentProcess()) {
+ WindowGlobalParent* window = ctx->Canonical()->GetCurrentWindowGlobal();
+ if (window) {
+ // Using the URI of the Principal and not the document because e.g.
+ // window.open inherits the principal and hence the URI of the
+ // opening context needed for same origin checks.
+ principal = window->DocumentPrincipal();
+ }
+ } else if (nsPIDOMWindowOuter* windowOuter = ctx->GetDOMWindow()) {
+ principal = nsGlobalWindowOuter::Cast(windowOuter)->GetPrincipal();
+ }
+
+ if (principal && principal->IsSystemPrincipal()) {
+ return true;
+ }
+
+ if (checkSameOrigin) {
+ bool isSameOrigin = principal && principal->IsSameOrigin(uri);
+ // one of the ancestors is not same origin as this document
+ if (!isSameOrigin) {
+ ReportError("XFrameOptionsDeny", aHttpChannel, uri, aPolicy);
+ return false;
+ }
+ }
+ ctx = ctx->GetParent();
+ }
+
+ // If the value of the header is DENY, and the previous condition is
+ // not met (current docshell is not the top docshell), prohibit the
+ // load.
+ if (aPolicy.LowerCaseEqualsLiteral("deny")) {
+ ReportError("XFrameOptionsDeny", aHttpChannel, uri, aPolicy);
+ return false;
+ }
+
+ return true;
+}
+
+// Ignore x-frame-options if CSP with frame-ancestors exists
+static bool ShouldIgnoreFrameOptions(nsIChannel* aChannel,
+ nsIContentSecurityPolicy* aCSP) {
+ NS_ENSURE_TRUE(aChannel, false);
+ if (!aCSP) {
+ return false;
+ }
+
+ bool enforcesFrameAncestors = false;
+ aCSP->GetEnforcesFrameAncestors(&enforcesFrameAncestors);
+ if (!enforcesFrameAncestors) {
+ // if CSP does not contain frame-ancestors, then there
+ // is nothing to do here.
+ return false;
+ }
+
+ return true;
+}
+
+// Check if X-Frame-Options permits this document to be loaded as a
+// subdocument. This will iterate through and check any number of
+// X-Frame-Options policies in the request (comma-separated in a header,
+// multiple headers, etc).
+/* static */
+bool FramingChecker::CheckFrameOptions(nsIChannel* aChannel,
+ nsIContentSecurityPolicy* aCsp,
+ bool& outIsFrameCheckingSkipped) {
+ if (!aChannel) {
+ return true;
+ }
+
+ nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+ ExtContentPolicyType contentType = loadInfo->GetExternalContentPolicyType();
+
+ // xfo check only makes sense for subdocument and object loads, if this is
+ // not a load of such type, there is nothing to do here.
+ if (contentType != ExtContentPolicy::TYPE_SUBDOCUMENT &&
+ contentType != ExtContentPolicy::TYPE_OBJECT) {
+ return true;
+ }
+
+ nsCOMPtr<nsIHttpChannel> httpChannel;
+ nsresult rv = nsContentSecurityUtils::GetHttpChannelFromPotentialMultiPart(
+ aChannel, getter_AddRefs(httpChannel));
+ if (NS_WARN_IF(NS_FAILED(rv))) {
+ return true;
+ }
+
+ // xfo can only hang off an httpchannel, if this is not an httpChannel
+ // then there is nothing to do here.
+ if (!httpChannel) {
+ return true;
+ }
+
+ // ignore XFO checks on channels that will be redirected
+ uint32_t responseStatus;
+ rv = httpChannel->GetResponseStatus(&responseStatus);
+ // GetResponseStatus returning failure is expected in several situations, so
+ // do not warn if it fails.
+ if (NS_FAILED(rv)) {
+ return true;
+ }
+ if (mozilla::net::nsHttpChannel::IsRedirectStatus(responseStatus)) {
+ return true;
+ }
+
+ nsAutoCString xfoHeaderCValue;
+ Unused << httpChannel->GetResponseHeader("X-Frame-Options"_ns,
+ xfoHeaderCValue);
+ NS_ConvertUTF8toUTF16 xfoHeaderValue(xfoHeaderCValue);
+
+ // if no header value, there's nothing to do.
+ if (xfoHeaderValue.IsEmpty()) {
+ return true;
+ }
+
+ // xfo checks are ignored in case CSP frame-ancestors is present,
+ // if so, there is nothing to do here.
+ if (ShouldIgnoreFrameOptions(aChannel, aCsp)) {
+ outIsFrameCheckingSkipped = true;
+ return true;
+ }
+
+ // iterate through all the header values (usually there's only one, but can
+ // be many. If any want to deny the load, deny the load.
+ nsCharSeparatedTokenizer tokenizer(xfoHeaderValue, ',');
+ while (tokenizer.hasMoreTokens()) {
+ const nsAString& tok = tokenizer.nextToken();
+ if (!CheckOneFrameOptionsPolicy(httpChannel, tok)) {
+ // if xfo blocks the load we are notifying observers for
+ // testing purposes because there is no event to gather
+ // what an iframe load was blocked or not.
+ nsCOMPtr<nsIURI> uri;
+ httpChannel->GetURI(getter_AddRefs(uri));
+ nsCOMPtr<nsIObserverService> observerService =
+ mozilla::services::GetObserverService();
+ nsAutoString policy(tok);
+ observerService->NotifyObservers(uri, "xfo-on-violate-policy",
+ policy.get());
+ return false;
+ }
+ }
+ return true;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 19:03:59 +0000