gecko-dev/dom/security/FramingChecker.cpp
sakshaat d781937a67 Bug 1517483 - Get rid of nsIScriptSecurityManager::IsSystemPrincipal r=bzbarsky
Replaced instances of callers in both C++ and JS files to query the state from the principal directly.

Differential Revision: https://phabricator.services.mozilla.com/D22532

--HG--
extra : moz-landing-system : lando
2019-03-24 20:36:25 +00:00

347 lines
11 KiB
C++

/* -*- 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 "nsCSPUtils.h"
#include "nsDocShell.h"
#include "nsIChannel.h"
#include "nsIConsoleService.h"
#include "nsIContentSecurityPolicy.h"
#include "nsIScriptError.h"
#include "nsNetUtil.h"
#include "nsQueryObject.h"
#include "mozilla/dom/nsCSPUtils.h"
#include "mozilla/dom/LoadURIOptionsBinding.h"
#include "mozilla/NullPrincipal.h"
using namespace mozilla;
/* static */
bool FramingChecker::CheckOneFrameOptionsPolicy(nsIHttpChannel* aHttpChannel,
const nsAString& aPolicy,
nsIDocShell* aDocShell) {
static const char allowFrom[] = "allow-from";
const uint32_t allowFromLen = ArrayLength(allowFrom) - 1;
bool isAllowFrom =
StringHead(aPolicy, allowFromLen).LowerCaseEqualsLiteral(allowFrom);
// return early if header does not have one of the values with meaning
if (!aPolicy.LowerCaseEqualsLiteral("deny") &&
!aPolicy.LowerCaseEqualsLiteral("sameorigin") && !isAllowFrom) {
return true;
}
nsCOMPtr<nsIURI> uri;
aHttpChannel->GetURI(getter_AddRefs(uri));
// XXXkhuey when does this happen? Is returning true safe here?
if (!aDocShell) {
return true;
}
// We need to check the location of this window and the location of the top
// window, if we're not the top. X-F-O: SAMEORIGIN requires that the
// document must be same-origin with top window. X-F-O: DENY requires that
// the document must never be framed.
nsCOMPtr<nsPIDOMWindowOuter> thisWindow = aDocShell->GetWindow();
// If we don't have DOMWindow there is no risk of clickjacking
if (!thisWindow) {
return true;
}
// GetScriptableTop, not GetTop, because we want this to respect
// <iframe mozbrowser> boundaries.
nsCOMPtr<nsPIDOMWindowOuter> topWindow = thisWindow->GetScriptableTop();
// if the document is in the top window, it's not in a frame.
if (thisWindow == topWindow) {
return true;
}
// Find the top docshell in our parent chain that doesn't have the system
// principal and use it for the principal comparison. Finding the top
// content-type docshell doesn't work because some chrome documents are
// loaded in content docshells (see bug 593387).
nsCOMPtr<nsIDocShellTreeItem> thisDocShellItem(aDocShell);
nsCOMPtr<nsIDocShellTreeItem> parentDocShellItem;
nsCOMPtr<nsIDocShellTreeItem> curDocShellItem = thisDocShellItem;
nsCOMPtr<Document> topDoc;
nsresult rv;
nsCOMPtr<nsIScriptSecurityManager> ssm =
do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
if (!ssm) {
MOZ_CRASH();
}
// 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<nsIURI> topUri;
// Traverse up the parent chain and stop when we see a docshell whose
// parent has a system principal, or a docshell corresponding to
// <iframe mozbrowser>.
while (NS_SUCCEEDED(
curDocShellItem->GetParent(getter_AddRefs(parentDocShellItem))) &&
parentDocShellItem) {
nsCOMPtr<nsIDocShell> curDocShell = do_QueryInterface(curDocShellItem);
if (curDocShell && curDocShell->GetIsMozBrowser()) {
break;
}
topDoc = parentDocShellItem->GetDocument();
if (topDoc) {
if (topDoc->NodePrincipal()->IsSystemPrincipal()) {
// Found a system-principled doc: last docshell was top.
break;
}
if (checkSameOrigin) {
topDoc->NodePrincipal()->GetURI(getter_AddRefs(topUri));
bool isPrivateWin =
topDoc->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId >
0;
rv = ssm->CheckSameOriginURI(uri, topUri, true, isPrivateWin);
// one of the ancestors is not same origin as this document
if (NS_FAILED(rv)) {
ReportXFOViolation(curDocShellItem, uri, eSAMEORIGIN);
return false;
}
}
} else {
return false;
}
curDocShellItem = parentDocShellItem;
}
// If this document has the top non-SystemPrincipal docshell it is not being
// framed or it is being framed by a chrome document, which we allow.
if (curDocShellItem == thisDocShellItem) {
return true;
}
// 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")) {
ReportXFOViolation(curDocShellItem, uri, eDENY);
return false;
}
topDoc = curDocShellItem->GetDocument();
topDoc->NodePrincipal()->GetURI(getter_AddRefs(topUri));
// If the X-Frame-Options value is "allow-from [uri]", then the top
// frame in the parent chain must be from that origin
if (isAllowFrom) {
if (aPolicy.Length() == allowFromLen ||
(aPolicy[allowFromLen] != ' ' && aPolicy[allowFromLen] != '\t')) {
ReportXFOViolation(curDocShellItem, uri, eALLOWFROM);
return false;
}
rv = NS_NewURI(getter_AddRefs(uri), Substring(aPolicy, allowFromLen));
if (NS_FAILED(rv)) {
return false;
}
bool isPrivateWin =
topDoc->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId > 0;
rv = ssm->CheckSameOriginURI(uri, topUri, true, isPrivateWin);
if (NS_FAILED(rv)) {
ReportXFOViolation(curDocShellItem, uri, eALLOWFROM);
return false;
}
}
return true;
}
// Ignore x-frame-options if CSP with frame-ancestors exists
static bool ShouldIgnoreFrameOptions(nsIChannel* aChannel,
nsIPrincipal* aPrincipal) {
NS_ENSURE_TRUE(aChannel, false);
NS_ENSURE_TRUE(aPrincipal, false);
nsCOMPtr<nsIContentSecurityPolicy> csp;
aPrincipal->GetCsp(getter_AddRefs(csp));
if (!csp) {
// if there is no CSP, then there is nothing to do here
return false;
}
bool enforcesFrameAncestors = false;
csp->GetEnforcesFrameAncestors(&enforcesFrameAncestors);
if (!enforcesFrameAncestors) {
// if CSP does not contain frame-ancestors, then there
// is nothing to do here.
return false;
}
// log warning to console that xfo is ignored because of CSP
nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
uint64_t innerWindowID = loadInfo->GetInnerWindowID();
bool privateWindow = !!loadInfo->GetOriginAttributes().mPrivateBrowsingId;
const char16_t* params[] = {u"x-frame-options", u"frame-ancestors"};
CSP_LogLocalizedStr("IgnoringSrcBecauseOfDirective", params,
ArrayLength(params),
EmptyString(), // no sourcefile
EmptyString(), // no scriptsample
0, // no linenumber
0, // no columnnumber
nsIScriptError::warningFlag,
NS_LITERAL_CSTRING("IgnoringSrcBecauseOfDirective"),
innerWindowID, privateWindow);
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,
nsIDocShell* aDocShell,
nsIPrincipal* aPrincipal) {
if (!aChannel || !aDocShell) {
return true;
}
if (ShouldIgnoreFrameOptions(aChannel, aPrincipal)) {
return true;
}
nsresult rv;
nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel);
if (!httpChannel) {
// check if it is hiding in a multipart channel
rv = nsDocShell::Cast(aDocShell)->GetHttpChannel(
aChannel, getter_AddRefs(httpChannel));
if (NS_FAILED(rv)) {
return false;
}
}
if (!httpChannel) {
return true;
}
nsAutoCString xfoHeaderCValue;
Unused << httpChannel->GetResponseHeader(
NS_LITERAL_CSTRING("X-Frame-Options"), xfoHeaderCValue);
NS_ConvertUTF8toUTF16 xfoHeaderValue(xfoHeaderCValue);
// if no header value, there's nothing to do.
if (xfoHeaderValue.IsEmpty()) {
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, aDocShell)) {
// cancel the load and display about:blank
httpChannel->Cancel(NS_BINDING_ABORTED);
if (aDocShell) {
nsCOMPtr<nsIWebNavigation> webNav(do_QueryObject(aDocShell));
if (webNav) {
nsCOMPtr<nsILoadInfo> loadInfo = httpChannel->LoadInfo();
RefPtr<NullPrincipal> principal =
NullPrincipal::CreateWithInheritedAttributes(
loadInfo->TriggeringPrincipal());
LoadURIOptions loadURIOptions;
loadURIOptions.mTriggeringPrincipal = principal;
webNav->LoadURI(NS_LITERAL_STRING("about:blank"), loadURIOptions);
}
}
return false;
}
}
return true;
}
/* static */
void FramingChecker::ReportXFOViolation(nsIDocShellTreeItem* aTopDocShellItem,
nsIURI* aThisURI, XFOHeader aHeader) {
MOZ_ASSERT(aTopDocShellItem, "Need a top docshell");
nsCOMPtr<nsPIDOMWindowOuter> topOuterWindow = aTopDocShellItem->GetWindow();
if (!topOuterWindow) {
return;
}
nsPIDOMWindowInner* topInnerWindow = topOuterWindow->GetCurrentInnerWindow();
if (!topInnerWindow) {
return;
}
nsCOMPtr<nsIURI> topURI;
nsCOMPtr<Document> document = aTopDocShellItem->GetDocument();
nsresult rv = document->NodePrincipal()->GetURI(getter_AddRefs(topURI));
if (NS_FAILED(rv)) {
return;
}
if (!topURI) {
return;
}
nsCString topURIString;
nsCString thisURIString;
rv = topURI->GetSpec(topURIString);
if (NS_FAILED(rv)) {
return;
}
rv = aThisURI->GetSpec(thisURIString);
if (NS_FAILED(rv)) {
return;
}
nsCOMPtr<nsIConsoleService> consoleService =
do_GetService(NS_CONSOLESERVICE_CONTRACTID);
nsCOMPtr<nsIScriptError> errorObject =
do_CreateInstance(NS_SCRIPTERROR_CONTRACTID);
if (!consoleService || !errorObject) {
return;
}
nsString msg = NS_LITERAL_STRING("Load denied by X-Frame-Options: ");
msg.Append(NS_ConvertUTF8toUTF16(thisURIString));
switch (aHeader) {
case eDENY:
msg.AppendLiteral(" does not permit framing.");
break;
case eSAMEORIGIN:
msg.AppendLiteral(" does not permit cross-origin framing.");
break;
case eALLOWFROM:
msg.AppendLiteral(" does not permit framing by ");
msg.Append(NS_ConvertUTF8toUTF16(topURIString));
msg.Append('.');
break;
}
// It is ok to use InitWithSanitizedSource, because the source string is
// empty.
rv = errorObject->InitWithSanitizedSource(
msg, EmptyString(), EmptyString(), 0, 0, nsIScriptError::errorFlag,
"X-Frame-Options", topInnerWindow->WindowID());
if (NS_FAILED(rv)) {
return;
}
consoleService->LogMessage(errorObject);
}