gecko-dev/dom/base/PostMessageEvent.cpp

185 lines
7.0 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 "PostMessageEvent.h"
#include "MessageEvent.h"
#include "mozilla/dom/BlobBinding.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/FileList.h"
#include "mozilla/dom/FileListBinding.h"
#include "mozilla/dom/MessageEventBinding.h"
#include "mozilla/dom/MessagePort.h"
#include "mozilla/dom/MessagePortBinding.h"
#include "mozilla/dom/PMessagePort.h"
#include "mozilla/dom/StructuredCloneTags.h"
#include "mozilla/dom/UnionConversions.h"
#include "mozilla/EventDispatcher.h"
#include "nsContentUtils.h"
#include "nsGlobalWindow.h"
#include "nsIPresShell.h"
#include "nsIPrincipal.h"
#include "nsIScriptError.h"
#include "nsPresContext.h"
#include "nsQueryObject.h"
namespace mozilla {
namespace dom {
PostMessageEvent::PostMessageEvent(nsGlobalWindow* aSource,
const nsAString& aCallerOrigin,
nsGlobalWindow* aTargetWindow,
nsIPrincipal* aProvidedPrincipal,
nsIDocument* aSourceDocument,
bool aTrustedCaller)
: StructuredCloneHolder(CloningSupported, TransferringSupported,
StructuredCloneScope::SameProcessSameThread),
mSource(aSource),
mCallerOrigin(aCallerOrigin),
mTargetWindow(aTargetWindow),
mProvidedPrincipal(aProvidedPrincipal),
mSourceDocument(aSourceDocument),
mTrustedCaller(aTrustedCaller)
{
}
PostMessageEvent::~PostMessageEvent()
{
}
NS_IMETHODIMP
PostMessageEvent::Run()
{
MOZ_ASSERT(mTargetWindow->IsOuterWindow(),
"should have been passed an outer window!");
MOZ_ASSERT(!mSource || mSource->IsOuterWindow(),
"should have been passed an outer window!");
// Note: We don't init this AutoJSAPI with targetWindow, because we do not
// want exceptions during message deserialization to trigger error events on
// targetWindow.
AutoJSAPI jsapi;
jsapi.Init();
JSContext* cx = jsapi.cx();
// The document is just used for the principal mismatch error message below.
// Use a stack variable so mSourceDocument is not held onto after this method
// finishes, regardless of the method outcome.
nsCOMPtr<nsIDocument> sourceDocument;
sourceDocument.swap(mSourceDocument);
// If we bailed before this point we're going to leak mMessage, but
// that's probably better than crashing.
RefPtr<nsGlobalWindow> targetWindow;
if (mTargetWindow->IsClosedOrClosing() ||
!(targetWindow = mTargetWindow->GetCurrentInnerWindowInternal()) ||
targetWindow->IsClosedOrClosing())
return NS_OK;
MOZ_ASSERT(targetWindow->IsInnerWindow(),
"we ordered an inner window!");
JSAutoCompartment ac(cx, targetWindow->GetWrapper());
// Ensure that any origin which might have been provided is the origin of this
// window's document. Note that we do this *now* instead of when postMessage
// is called because the target window might have been navigated to a
// different location between then and now. If this check happened when
// postMessage was called, it would be fairly easy for a malicious webpage to
// intercept messages intended for another site by carefully timing navigation
// of the target window so it changed location after postMessage but before
// now.
if (mProvidedPrincipal) {
// Get the target's origin either from its principal or, in the case the
// principal doesn't carry a URI (e.g. the system principal), the target's
// document.
nsIPrincipal* targetPrin = targetWindow->GetPrincipal();
if (NS_WARN_IF(!targetPrin))
return NS_OK;
// Note: This is contrary to the spec with respect to file: URLs, which
// the spec groups into a single origin, but given we intentionally
// don't do that in other places it seems better to hold the line for
// now. Long-term, we want HTML5 to address this so that we can
// be compliant while being safer.
if (!BasePrincipal::Cast(targetPrin)->EqualsIgnoringAddonId(mProvidedPrincipal)) {
nsAutoString providedOrigin, targetOrigin;
nsresult rv = nsContentUtils::GetUTFOrigin(targetPrin, targetOrigin);
NS_ENSURE_SUCCESS(rv, rv);
rv = nsContentUtils::GetUTFOrigin(mProvidedPrincipal, providedOrigin);
NS_ENSURE_SUCCESS(rv, rv);
MOZ_DIAGNOSTIC_ASSERT(providedOrigin != targetOrigin ||
(BasePrincipal::Cast(mProvidedPrincipal)->OriginAttributesRef() ==
BasePrincipal::Cast(targetPrin)->OriginAttributesRef()),
"Unexpected postMessage call to a window with mismatched "
"origin attributes");
const char16_t* params[] = { providedOrigin.get(), targetOrigin.get() };
nsContentUtils::ReportToConsole(nsIScriptError::errorFlag,
NS_LITERAL_CSTRING("DOM Window"), sourceDocument,
nsContentUtils::eDOM_PROPERTIES,
"TargetPrincipalDoesNotMatch",
params, ArrayLength(params));
return NS_OK;
}
}
ErrorResult rv;
JS::Rooted<JS::Value> messageData(cx);
nsCOMPtr<nsPIDOMWindowInner> window = targetWindow->AsInner();
Read(window, cx, &messageData, rv);
if (NS_WARN_IF(rv.Failed())) {
return rv.StealNSResult();
}
// Create the event
nsCOMPtr<mozilla::dom::EventTarget> eventTarget = do_QueryObject(targetWindow);
RefPtr<MessageEvent> event =
new MessageEvent(eventTarget, nullptr, nullptr);
Nullable<WindowProxyOrMessagePort> source;
source.SetValue().SetAsWindowProxy() = mSource ? mSource->AsOuter() : nullptr;
Sequence<OwningNonNull<MessagePort>> ports;
if (!TakeTransferredPortsAsSequence(ports)) {
return NS_ERROR_OUT_OF_MEMORY;
}
event->InitMessageEvent(nullptr, NS_LITERAL_STRING("message"),
false /*non-bubbling */, false /*cancelable */,
messageData, mCallerOrigin,
EmptyString(), source, ports);
// We can't simply call dispatchEvent on the window because doing so ends
// up flipping the trusted bit on the event, and we don't want that to
// happen because then untrusted content can call postMessage on a chrome
// window if it can get a reference to it.
nsIPresShell *shell = targetWindow->GetExtantDoc()->GetShell();
RefPtr<nsPresContext> presContext;
if (shell)
presContext = shell->GetPresContext();
event->SetTrusted(mTrustedCaller);
WidgetEvent* internalEvent = event->WidgetEventPtr();
nsEventStatus status = nsEventStatus_eIgnore;
EventDispatcher::Dispatch(window,
presContext,
internalEvent,
static_cast<dom::Event*>(event.get()),
&status);
return NS_OK;
}
} // namespace dom
} // namespace mozilla