Implement the private API for quick unlock.

chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/extensions/quick_unlock_private/quick_unlock_private_api.h"
+
+#include "chrome/browser/chromeos/login/quick_unlock/pin_storage.h"
+#include "chrome/browser/chromeos/login/quick_unlock/pin_storage_factory.h"
+#include "chrome/browser/chromeos/profiles/profile_helper.h"
+#include "chromeos/login/auth/extended_authenticator.h"
+#include "chromeos/login/auth/user_context.h"
+#include "extensions/browser/event_router.h"
+
+namespace quick_unlock_private = extensions::api::quick_unlock_private;

[stevenjb, 2016/06/22 21:35:21]

nit: Unnecessary if you put all of this inside namespace extensions {

[jdufault, 2016/06/23 00:14:20]

Done.

+namespace SetModes = quick_unlock_private::SetModes;
+namespace GetActiveModes = quick_unlock_private::GetActiveModes;
+namespace GetAvailableModes = quick_unlock_private::GetAvailableModes;
+namespace OnActiveModesChanged = quick_unlock_private::OnActiveModesChanged;
+using QuickUnlockMode = quick_unlock_private::QuickUnlockMode;

[stevenjb, 2016/06/22 21:35:20]

nit: FWIW, I generally find using the full name more clear in the glue code to
differentiate between the API namespace and the model namespace.

[jdufault, 2016/06/23 00:14:19]

Keeping existing approach as discussed offline.

+using ModeList = std::vector<QuickUnlockMode>;

[stevenjb, 2016/06/22 21:35:21]

nit: for those of us unfamiliar with the code, UqickUnlockModeList would be more
clear, even if it is more verbose.

[jdufault, 2016/06/23 00:14:20]

Done.

+
+namespace extensions {
+
+namespace {
+
+const char kModesAndCredentialsLengthMismatch[] =
+    "|modes| and |credentials| must have the same number of elements";
+const char kMultipleModesNotSupported[] =
+    "Currently at most one quick unlock mode can be active.";

[stevenjb, 2016/06/22 21:35:21]

nit: Remove "Currently"

[jdufault, 2016/06/23 00:14:19]

Done.

+
+// Returns the active set of quick unlock modes.
+ModeList GetActiveModes(Profile* profile) {
+  ModeList modes;
+
+  chromeos::PinStorage* pin_storage =
+      chromeos::PinStorageFactory::GetForProfile(profile);
+  if (pin_storage->IsPinSet())
+    modes.push_back(quick_unlock_private::QUICK_UNLOCK_MODE_PIN);
+
+  return modes;
+}
+
+// Returns true if |a| and |b| contain the same elements. The elements do not
+// need to be in the same order.
+bool AreModesEqual(const ModeList& a, const ModeList& b) {
+  if (a.size() != b.size())
+    return false;
+
+  // This is a slow comparison algorithm, but the number of entries in |a| and
+  // |b| will always be very low (0-3 items) so it doesn't matter.
+  for (size_t i = 0; i < a.size(); ++i) {
+    if (std::find(b.begin(), b.end(), a[i]) == b.end())
+      return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+//////////// quickUnlockPrivate.getAvailableModes

[stevenjb, 2016/06/22 21:35:20]

nit: Just '// quickUnlockPrivate.getAvailableModes' should be sufficient and is
more common.

[jdufault, 2016/06/23 00:14:20]

Done.

+
+QuickUnlockPrivateGetAvailableModesFunction::
+    QuickUnlockPrivateGetAvailableModesFunction()
+    : chrome_details_(this) {}
+
+QuickUnlockPrivateGetAvailableModesFunction::
+    ~QuickUnlockPrivateGetAvailableModesFunction() {}
+
+ExtensionFunction::ResponseAction
+QuickUnlockPrivateGetAvailableModesFunction::Run() {
+  // TODO(jdufault): Check for policy and do not return PIN if policy makes it
+  // unavailable. See crbug.com/612271.
+  const ModeList modes = {quick_unlock_private::QUICK_UNLOCK_MODE_PIN};
+
+  return RespondNow(ArgumentList(GetAvailableModes::Results::Create(modes)));
+}
+
+//////////// quickUnlockPrivate.getActiveModes
+
+QuickUnlockPrivateGetActiveModesFunction::
+    QuickUnlockPrivateGetActiveModesFunction()
+    : chrome_details_(this) {}
+
+QuickUnlockPrivateGetActiveModesFunction::
+    ~QuickUnlockPrivateGetActiveModesFunction() {}
+
+ExtensionFunction::ResponseAction
+QuickUnlockPrivateGetActiveModesFunction::Run() {
+  const ModeList modes = GetActiveModes(chrome_details_.GetProfile());
+  return RespondNow(ArgumentList(GetActiveModes::Results::Create(modes)));
+}
+
+//////////// quickUnlockPrivate.setModes
+
+QuickUnlockPrivateSetModesFunction::QuickUnlockPrivateSetModesFunction()
+    : chrome_details_(this) {}
+
+QuickUnlockPrivateSetModesFunction::~QuickUnlockPrivateSetModesFunction() {}
+
+void QuickUnlockPrivateSetModesFunction::SetAuthenticatorAllocatorForTesting(
+    const QuickUnlockPrivateSetModesFunction::AuthenticatorAllocator&
+        allocator) {
+  authenticator_allocator_ = allocator;
+}
+
+void QuickUnlockPrivateSetModesFunction::SetModesChangedEventHandlerForTesting(
+    const ModesChangedEventHandler& handler) {
+  modes_changed_handler_ = handler;
+}
+
+ExtensionFunction::ResponseAction QuickUnlockPrivateSetModesFunction::Run() {
+  params_ = SetModes::Params::Create(*args_);
+  EXTENSION_FUNCTION_VALIDATE(params_.get());
+
+  if (params_->modes.size() != params_->credentials.size())
+    return RespondNow(Error(kModesAndCredentialsLengthMismatch));
+
+  if (params_->modes.size() > 1)
+    return RespondNow(Error(kMultipleModesNotSupported));
+
+  user_manager::User* user = chromeos::ProfileHelper::Get()->GetUserByProfile(
+      chrome_details_.GetProfile());
+  chromeos::UserContext user_context(user->GetAccountId());
+  user_context.SetKey(chromeos::Key(params_->account_password));
+
+  // The extension function needs to stay alive while the authenticator is
+  // running the password check. Add a ref before the authenticator starts, and
+  // remove the ref after it invokes one of the OnAuth* callbacks.
+  AddRef();

[stevenjb, 2016/06/22 21:35:21]

Why not make this an AsyncExtensionFunction and use RunAsync instead?

[Devlin, 2016/06/22 21:47:04]

NoNoNo.  AsyncExtensionFunction uber deprecated and must die!

Async/Sync extension functions are really silly idioms that don't make much
sense, and don't allow for possibly returning synchronously/asynchronously (and
cause tons of fun lifetime issues!).  Vanilla ExtensionFunctions are much more
clear what's going on.

[stevenjb, 2016/06/22 22:02:19]

I see. Thanks for correcting me. I find the explict AddRef / Release
unfortunate, but listen to Devlin not to me :)

We should try to aggressively eliminate AsyncExtensionFunction so that we don't
continue to have bad examples in the code.

+
+  // Lazily allocate the authenticator. We do this here, instead of in the ctor,
+  // so that tests can install a fake.
+  if (authenticator_allocator_.is_null())
+    extended_authenticator_ = chromeos::ExtendedAuthenticator::Create(this);
+  else
+    extended_authenticator_ = authenticator_allocator_.Run(this);
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(&chromeos::ExtendedAuthenticator::AuthenticateToCheck,
+                 extended_authenticator_.get(), user_context, base::Closure()));
+
+  return RespondLater();
+}
+
+void QuickUnlockPrivateSetModesFunction::OnAuthFailure(
+    const chromeos::AuthFailure& error) {
+  Respond(ArgumentList(SetModes::Results::Create(false)));
+  Release();  // Balanced in Run().
+}
+
+void QuickUnlockPrivateSetModesFunction::OnAuthSuccess(
+    const chromeos::UserContext& user_context) {
+  const ModeList initial_modes = GetActiveModes(chrome_details_.GetProfile());
+  ApplyModeChange();
+  const ModeList updated_modes = GetActiveModes(chrome_details_.GetProfile());
+
+  if (!AreModesEqual(initial_modes, updated_modes))
+    FireEvent(updated_modes);
+
+  Respond(ArgumentList(SetModes::Results::Create(true)));
+  Release();  // Balanced in Run().
+}
+
+void QuickUnlockPrivateSetModesFunction::ApplyModeChange() {
+  // This function is setup so it is easy to add another quick unlock mode while
+  // following all of the invariants, which are:
+  //
+  // 1: If an unlock type is not specified, it should be deactivated.
+  // 2: If a credential for an unlock type is empty, it should not be touched.
+  // 3: Otherwise, the credential should be set to the new value.
+
+  bool update_pin = true;
+  std::string pin_credential;
+
+  // Compute needed changes.
+  for (size_t i = 0; i < params_->modes.size(); ++i) {
+    const QuickUnlockMode mode = params_->modes[i];
+    const std::string& credential = params_->credentials[i];
+
+    if (mode == quick_unlock_private::QUICK_UNLOCK_MODE_PIN) {
+      update_pin = !credential.empty();
+      pin_credential = credential;
+    }
+  }
+
+  // Apply changes.
+  if (update_pin) {
+    Profile* profile = chrome_details_.GetProfile();
+    chromeos::PinStorage* pin_storage =
+        chromeos::PinStorageFactory::GetForProfile(profile);
+
+    if (pin_credential.empty())
+      pin_storage->RemovePin();
+    else
+      pin_storage->SetPin(pin_credential);
+  }
+}
+
+// Triggers a QuickUnlockMode change event.
+void QuickUnlockPrivateSetModesFunction::FireEvent(const ModeList& modes) {
+  // Allow unit tests to override how events are raised/handled.
+  if (!modes_changed_handler_.is_null()) {
+    modes_changed_handler_.Run(modes);
+    return;
+  }
+
+  std::unique_ptr<base::ListValue> args = OnActiveModesChanged::Create(modes);
+  std::unique_ptr<Event> event(
+      new Event(events::QUICK_UNLOCK_PRIVATE_ON_ACTIVE_MODES_CHANGED,
+                OnActiveModesChanged::kEventName, std::move(args)));
+  EventRouter::Get(browser_context())->BroadcastEvent(std::move(event));
+}
+
+}  // namespace extensions