gecko-dev/browser/components/shell/Windows11LimitedAccessFeatures.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

/**
 * This file exists so that LaunchModernSettingsDialogDefaultApps can be called
 * without linking to libxul.
 */
#include "Windows11LimitedAccessFeatures.h"

// MINGW32 is not supported for these features
// Fall back function defined in the #else
#ifndef __MINGW32__

#  include "nsString.h"
#  include "nsWindowsHelpers.h"

#  include "mozilla/Atomics.h"

#  include <wrl.h>
#  include <inspectable.h>
#  include <roapi.h>
#  include <windows.services.store.h>
#  include <windows.foundation.h>

using namespace Microsoft::WRL;
using namespace Microsoft::WRL::Wrappers;
using namespace ABI::Windows;
using namespace ABI::Windows::Foundation;
using namespace ABI::Windows::ApplicationModel;

struct LimitedAccessFeatureInfo {
  const WCHAR* feature;
  const WCHAR* token;
  const WCHAR* attestation;
};

/**
 * To unlock features, we need a feature identifier, a token, and an
 * attestation string. The token is generated by Microsoft and must
 * match the publisher id Microsoft thinks we have.
 *
 * To get a token, find the right microsoft email address by doing
 * a search on the web for the feature you want unlocked and reach
 * out to the right people at Microsoft.
 *
 * The token is generated from Microsoft.
 * The jumbled code in the attestation string is a publisher id and
 * must match the code in the resources / .rc file for the identity
 * looking like this:
 *
 * Identity LimitedAccessFeature {{ L"MozillaFirefox_pcsmm0jrprpb2" }}
 *
 * That is injected into our build in create_rc.py and is necessary
 * to unlock the taskbar pinning feature / APIs from an unpackaged
 * build.
 *
 */
LimitedAccessFeatureInfo releaseTabPinningInfo{
    L"com.microsoft.windows.taskbar.pin", L"kRFiWpEK5uS6PMJZKmR7MQ==",
    L"pcsmm0jrprpb2 has registered their use of "
    L"com.microsoft.windows.taskbar.pin with Microsoft and agrees to the terms "
    L"of use."};

/*
// these keys were also provided by Microsoft. They require matching changes to
create_rc.py

LimitedAccessFeatureInfo betaTabPinningInfo {
  L"com.microsoft.windows.taskbar.pin",
  L"RGEhsYgKhmPLKyzkEHnMhQ==",
  L"pcsmm0jrprpb2 has registered their use of com.microsoft.windows.taskbar.pin
with Microsoft and agrees to the terms of use."
};

LimitedAccessFeatureInfo nightlyTabPinningInfo {
  L"com.microsoft.windows.taskbar.pin",
  L"qbVzns/9kT+t15YbIwT4Jw==",
  L"pcsmm0jrprpb2 has registered their use of com.microsoft.windows.taskbar.pin
with Microsoft and agrees to the terms of use."
};
*/

static LimitedAccessFeatureInfo limitedAccessFeatureInfo[] = {
    {// Win11LimitedAccessFeatureType::Taskbar
     releaseTabPinningInfo}};

/**
 Implementation of the Win11LimitedAccessFeaturesInterface.
 */
class Win11LimitedAccessFeatures : public Win11LimitedAccessFeaturesInterface {
 public:
  using AtomicState = mozilla::Atomic<int, mozilla::SequentiallyConsistent>;

  mozilla::Result<bool, HRESULT> Unlock(
      Win11LimitedAccessFeatureType feature) override;

 private:
  AtomicState& GetState(Win11LimitedAccessFeatureType feature);
  mozilla::Result<bool, HRESULT> UnlockImplementation(
      Win11LimitedAccessFeatureType feature);

  /**
   * Store the state as an atomic so that it can be safely accessed from
   * different threads.
   */
  static AtomicState mTaskbarState;
  static AtomicState mDefaultState;

  enum State {
    Uninitialized,
    Locked,
    Unlocked,
  };
};

Win11LimitedAccessFeatures::AtomicState
    Win11LimitedAccessFeatures::mTaskbarState(
        Win11LimitedAccessFeatures::Uninitialized);
Win11LimitedAccessFeatures::AtomicState
    Win11LimitedAccessFeatures::mDefaultState(
        Win11LimitedAccessFeatures::Uninitialized);

RefPtr<Win11LimitedAccessFeaturesInterface>
CreateWin11LimitedAccessFeaturesInterface() {
  RefPtr<Win11LimitedAccessFeaturesInterface> result(
      new Win11LimitedAccessFeatures());
  return result;
}

mozilla::Result<bool, HRESULT> Win11LimitedAccessFeatures::Unlock(
    Win11LimitedAccessFeatureType feature) {
  AtomicState& atomicState = GetState(feature);

  int state = atomicState;
  if (state != Uninitialized) {
    return (state == Unlocked);
  }

  // If multiple threads read the state at the same time, and it's unitialized,
  // both threads will unlock the feature. This situation is unlikely, but even
  // if it happens, it's not a problem.

  auto result = UnlockImplementation(feature);

  int newState = Locked;
  if (!result.isErr() && result.unwrap()) {
    newState = Unlocked;
  }

  atomicState = newState;

  return result;
}

Win11LimitedAccessFeatures::AtomicState& Win11LimitedAccessFeatures::GetState(
    Win11LimitedAccessFeatureType feature) {
  switch (feature) {
    case Win11LimitedAccessFeatureType::Taskbar:
      return mTaskbarState;

    default:
      MOZ_ASSERT(false,
                 "Unhandled feature type! Add a new atomic state variable, add "
                 "that entry to the switch statement above, and add the proper "
                 "entries for the feature and the token.");
      return mDefaultState;
  }
}

mozilla::Result<bool, HRESULT> Win11LimitedAccessFeatures::UnlockImplementation(
    Win11LimitedAccessFeatureType feature) {
  ComPtr<ILimitedAccessFeaturesStatics> limitedAccessFeatures;
  ComPtr<ILimitedAccessFeatureRequestResult> limitedAccessFeaturesResult;

  HRESULT hr = RoGetActivationFactory(
      HStringReference(
          RuntimeClass_Windows_ApplicationModel_LimitedAccessFeatures)
          .Get(),
      IID_ILimitedAccessFeaturesStatics, &limitedAccessFeatures);

  if (!SUCCEEDED(hr)) {
    return mozilla::Err(hr);
  }

  const auto& lafInfo = limitedAccessFeatureInfo[static_cast<int>(feature)];

  hr = limitedAccessFeatures->TryUnlockFeature(
      HStringReference(lafInfo.feature).Get(),
      HStringReference(lafInfo.token).Get(),
      HStringReference(lafInfo.attestation).Get(),
      &limitedAccessFeaturesResult);
  if (!SUCCEEDED(hr)) {
    return mozilla::Err(hr);
  }

  LimitedAccessFeatureStatus status;
  hr = limitedAccessFeaturesResult->get_Status(&status);
  if (!SUCCEEDED(hr)) {
    return mozilla::Err(hr);
  }

  int state = Unlocked;
  if ((status != LimitedAccessFeatureStatus_Available) &&
      (status != LimitedAccessFeatureStatus_AvailableWithoutToken)) {
    state = Locked;
  }

  return (state == Unlocked);
}

#else  // MINGW32 implementation

RefPtr<Win11LimitedAccessFeaturesInterface>
CreateWin11LimitedAccessFeaturesInterface() {
  RefPtr<Win11LimitedAccessFeaturesInterface> result;
  return result;
}

#endif