gecko-dev/dom/serviceworkers/ServiceWorkerUtils.cpp

/* -*- 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 "ServiceWorkerUtils.h"

#include "mozilla/Preferences.h"
#include "mozilla/dom/ClientInfo.h"
#include "mozilla/dom/ServiceWorkerRegistrarTypes.h"
#include "nsCOMPtr.h"
#include "nsIPrincipal.h"
#include "nsIURL.h"

namespace mozilla {
namespace dom {

bool ServiceWorkerParentInterceptEnabled() {
  static Atomic<bool> sEnabled;
  static Atomic<bool> sInitialized;
  if (!sInitialized) {
    AssertIsOnMainThread();
    sInitialized = true;
    sEnabled =
        Preferences::GetBool("dom.serviceWorkers.parent_intercept", false);
  }
  return sEnabled;
}

bool ServiceWorkerRegistrationDataIsValid(
    const ServiceWorkerRegistrationData& aData) {
  return !aData.scope().IsEmpty() && !aData.currentWorkerURL().IsEmpty() &&
         !aData.cacheName().IsEmpty();
}

namespace {

void CheckForSlashEscapedCharsInPath(nsIURI* aURI, const char* aURLDescription,
                                     ErrorResult& aRv) {
  MOZ_ASSERT(aURI);

  // A URL that can't be downcast to a standard URL is an invalid URL and should
  // be treated as such and fail with SecurityError.
  nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
  if (NS_WARN_IF(!url)) {
    // This really should not happen, since the caller checks that we
    // have an http: or https: URL!
    aRv.ThrowInvalidStateError("http: or https: URL without a concept of path");
    return;
  }

  nsAutoCString path;
  nsresult rv = url->GetFilePath(path);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    // Again, should not happen.
    aRv.ThrowInvalidStateError("http: or https: URL without a concept of path");
    return;
  }

  ToLowerCase(path);
  if (path.Find("%2f") != kNotFound || path.Find("%5c") != kNotFound) {
    nsPrintfCString err("%s contains %%2f or %%5c", aURLDescription);
    aRv.ThrowTypeError(err);
  }
}

}  // anonymous namespace

void ServiceWorkerScopeAndScriptAreValid(const ClientInfo& aClientInfo,
                                         nsIURI* aScopeURI, nsIURI* aScriptURI,
                                         ErrorResult& aRv) {
  MOZ_DIAGNOSTIC_ASSERT(aScopeURI);
  MOZ_DIAGNOSTIC_ASSERT(aScriptURI);

  auto principalOrErr = aClientInfo.GetPrincipal();
  if (NS_WARN_IF(principalOrErr.isErr())) {
    aRv.ThrowInvalidStateError("Can't make security decisions about Client");
    return;
  }

  auto hasHTTPScheme = [](nsIURI* aURI) -> bool {
    return aURI->SchemeIs("http") || aURI->SchemeIs("https");
  };
  auto hasMozExtScheme = [](nsIURI* aURI) -> bool {
    return aURI->SchemeIs("moz-extension");
  };

  nsCOMPtr<nsIPrincipal> principal = principalOrErr.unwrap();

  auto isExtension = !!BasePrincipal::Cast(principal)->AddonPolicy();
  auto hasValidURISchemes = !isExtension ? hasHTTPScheme : hasMozExtScheme;

  // https://w3c.github.io/ServiceWorker/#start-register-algorithm step 3.
  if (!hasValidURISchemes(aScriptURI)) {
    auto message = !isExtension
                       ? "Script URL's scheme is not 'http' or 'https'"_ns
                       : "Script URL's scheme is not 'moz-extension'"_ns;
    aRv.ThrowTypeError(message);
    return;
  }

  // https://w3c.github.io/ServiceWorker/#start-register-algorithm step 4.
  CheckForSlashEscapedCharsInPath(aScriptURI, "script URL", aRv);
  if (NS_WARN_IF(aRv.Failed())) {
    return;
  }

  // https://w3c.github.io/ServiceWorker/#start-register-algorithm step 8.
  if (!hasValidURISchemes(aScopeURI)) {
    auto message = !isExtension
                       ? "Scope URL's scheme is not 'http' or 'https'"_ns
                       : "Scope URL's scheme is not 'moz-extension'"_ns;
    aRv.ThrowTypeError(message);
    return;
  }

  // https://w3c.github.io/ServiceWorker/#start-register-algorithm step 9.
  CheckForSlashEscapedCharsInPath(aScopeURI, "scope URL", aRv);
  if (NS_WARN_IF(aRv.Failed())) {
    return;
  }

  // The refs should really be empty coming in here, but if someone
  // injects bad data into IPC, who knows.  So let's revalidate that.
  nsAutoCString ref;
  Unused << aScopeURI->GetRef(ref);
  if (NS_WARN_IF(!ref.IsEmpty())) {
    aRv.ThrowSecurityError("Non-empty fragment on scope URL");
    return;
  }

  Unused << aScriptURI->GetRef(ref);
  if (NS_WARN_IF(!ref.IsEmpty())) {
    aRv.ThrowSecurityError("Non-empty fragment on script URL");
    return;
  }

  // Unfortunately we don't seem to have an obvious window id here; in
  // particular ClientInfo does not have one.
  nsresult rv = principal->CheckMayLoadWithReporting(
      aScopeURI, false /* allowIfInheritsPrincipal */, 0 /* innerWindowID */);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    aRv.ThrowSecurityError("Scope URL is not same-origin with Client");
    return;
  }

  rv = principal->CheckMayLoadWithReporting(
      aScriptURI, false /* allowIfInheritsPrincipal */, 0 /* innerWindowID */);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    aRv.ThrowSecurityError("Script URL is not same-origin with Client");
    return;
  }
}

}  // namespace dom
}  // namespace mozilla