Implement GetServerBackedStateKeys API in SessionManagerClient.

This call is used to request the current server-backed state keys from
session_manager.

BUG=chromium:358213
TEST=None

Review URL: https://codereview.chromium.org/240373003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@268360 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 96 insertions, 0 deletions

diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.cc b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
index 70acbd0..922dc29 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.cc
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
@@ -181,6 +181,9 @@ void DeviceSettingsTestHelper::SetFlagsForUser(
     const std::string& account_id,
     const std::vector<std::string>& flags) {}
 
+void DeviceSettingsTestHelper::GetServerBackedStateKeys(
+    const StateKeysCallback& callback) {}
+
 DeviceSettingsTestHelper::PolicyState::PolicyState()
     : store_result_(true) {}
 
diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.h b/chrome/browser/chromeos/settings/device_settings_test_helper.h
index cb299d8..af683d0 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.h
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.h
@@ -119,6 +119,8 @@ class DeviceSettingsTestHelper : public SessionManagerClient {
   virtual void SetFlagsForUser(
       const std::string& account_id,
       const std::vector<std::string>& flags) OVERRIDE;
+  virtual void GetServerBackedStateKeys(
+      const StateKeysCallback& callback) OVERRIDE;
 
  private:
   struct PolicyState {
diff --git a/chromeos/dbus/fake_session_manager_client.cc b/chromeos/dbus/fake_session_manager_client.cc
index ade94f52..e2f9404 100644
--- a/chromeos/dbus/fake_session_manager_client.cc
+++ b/chromeos/dbus/fake_session_manager_client.cc
@@ -135,6 +135,12 @@ void FakeSessionManagerClient::SetFlagsForUser(
     const std::vector<std::string>& flags) {
 }
 
+void FakeSessionManagerClient::GetServerBackedStateKeys(
+    const StateKeysCallback& callback) {
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(callback, server_backed_state_keys_));
+}
+
 const std::string& FakeSessionManagerClient::device_policy() const {
   return device_policy_;
 }
diff --git a/chromeos/dbus/fake_session_manager_client.h b/chromeos/dbus/fake_session_manager_client.h
index 1be814a..1a6c782 100644
--- a/chromeos/dbus/fake_session_manager_client.h
+++ b/chromeos/dbus/fake_session_manager_client.h
@@ -7,6 +7,7 @@
 
 #include <map>
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ -60,6 +61,8 @@ class FakeSessionManagerClient : public SessionManagerClient {
       const StorePolicyCallback& callback) OVERRIDE;
   virtual void SetFlagsForUser(const std::string& username,
                                const std::vector<std::string>& flags) OVERRIDE;
+  virtual void GetServerBackedStateKeys(const StateKeysCallback& callback)
+      OVERRIDE;
 
   const std::string& device_policy() const;
   void set_device_policy(const std::string& policy_blob);
@@ -76,6 +79,13 @@ class FakeSessionManagerClient : public SessionManagerClient {
   // Notify observers about a property change completion.
   void OnPropertyChangeComplete(bool success);
 
+  // Configures the list of state keys used to satisfy
+  // GetServerBackedStateKeys() requests.
+  void set_server_backed_state_keys(
+      const std::vector<std::string>& state_keys) {
+    server_backed_state_keys_ = state_keys;
+  }
+
   int start_device_wipe_call_count() const {
     return start_device_wipe_call_count_;
   }
@@ -96,6 +106,7 @@ class FakeSessionManagerClient : public SessionManagerClient {
   std::map<std::string, std::string> device_local_account_policy_;
   ObserverList<Observer> observers_;
   SessionManagerClient::ActiveSessionsMap user_sessions_;
+  std::vector<std::string> server_backed_state_keys_;
 
   int start_device_wipe_call_count_;
   int notify_lock_screen_shown_call_count_;
diff --git a/chromeos/dbus/mock_session_manager_client.h b/chromeos/dbus/mock_session_manager_client.h
index 7d679b8..6847ee0 100644
--- a/chromeos/dbus/mock_session_manager_client.h
+++ b/chromeos/dbus/mock_session_manager_client.h
@@ -54,6 +54,7 @@ class MockSessionManagerClient : public SessionManagerClient {
   MOCK_METHOD2(SetFlagsForUser,
                void(const std::string&,
                     const std::vector<std::string>&));
+  MOCK_METHOD1(GetServerBackedStateKeys, void(const StateKeysCallback&));
 };
 
 }  // namespace chromeos
diff --git a/chromeos/dbus/session_manager_client.cc b/chromeos/dbus/session_manager_client.cc
index 44d1e0c..c5693a8 100644
--- a/chromeos/dbus/session_manager_client.cc
+++ b/chromeos/dbus/session_manager_client.cc
@@ -10,12 +10,14 @@
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/path_service.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/task_runner_util.h"
 #include "base/threading/worker_pool.h"
 #include "chromeos/chromeos_paths.h"
 #include "chromeos/dbus/blocking_method_caller.h"
 #include "chromeos/dbus/cryptohome_client.h"
+#include "crypto/sha2.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_path.h"
@@ -269,6 +271,20 @@ class SessionManagerClientImpl : public SessionManagerClient {
         dbus::ObjectProxy::EmptyResponseCallback());
   }
 
+  virtual void GetServerBackedStateKeys(const StateKeysCallback& callback)
+      OVERRIDE {
+    dbus::MethodCall method_call(
+        login_manager::kSessionManagerInterface,
+        login_manager::kSessionManagerGetServerBackedStateKeys);
+
+    session_manager_proxy_->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&SessionManagerClientImpl::OnGetServerBackedStateKeys,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   callback));
+  }
+
  protected:
   virtual void Init(dbus::Bus* bus) OVERRIDE {
     session_manager_proxy_ = bus->GetObjectProxy(
@@ -515,6 +531,39 @@ class SessionManagerClientImpl : public SessionManagerClient {
     LOG_IF(ERROR, !success) << "Failed to connect to " << signal_name;
   }
 
+  // Called when kSessionManagerGetServerBackedStateKeys method is complete.
+  void OnGetServerBackedStateKeys(const StateKeysCallback& callback,
+                                  dbus::Response* response) {
+    std::vector<std::string> state_keys;
+    if (!response) {
+      LOG(ERROR) << "Failed to call "
+                 << login_manager::kSessionManagerStartSession;
+    } else {
+      dbus::MessageReader reader(response);
+      dbus::MessageReader array_reader(NULL);
+
+      if (!reader.PopArray(&array_reader)) {
+        LOG(ERROR) << "Bad response: " << response->ToString();
+      } else {
+        while (array_reader.HasMoreData()) {
+          const uint8* data = NULL;
+          size_t size = 0;
+          if (!array_reader.PopArrayOfBytes(&data, &size)) {
+            LOG(ERROR) << "Bad response: " << response->ToString();
+            state_keys.clear();
+            break;
+          }
+          state_keys.push_back(
+              std::string(reinterpret_cast<const char*>(data), size));
+        }
+      }
+    }
+
+    if (!callback.is_null())
+      callback.Run(state_keys);
+  }
+
+
   dbus::ObjectProxy* session_manager_proxy_;
   scoped_ptr<BlockingMethodCaller> blocking_method_caller_;
   ObserverList<Observer> observers_;
@@ -681,6 +730,17 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
   virtual void SetFlagsForUser(const std::string& username,
                                const std::vector<std::string>& flags) OVERRIDE {
   }
+
+  virtual void GetServerBackedStateKeys(const StateKeysCallback& callback)
+      OVERRIDE {
+    std::vector<std::string> state_keys;
+    for (int i = 0; i < 5; ++i)
+      state_keys.push_back(crypto::SHA256HashString(base::IntToString(i)));
+
+    if (!callback.is_null())
+      callback.Run(state_keys);
+  }
+
  private:
   StubDelegate* delegate_;  // Weak pointer; may be NULL.
   ObserverList<Observer> observers_;
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index 2a5792d..a9ae670 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -7,6 +7,7 @@
 
 #include <map>
 #include <string>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/observer_list.h"
@@ -172,6 +173,18 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void SetFlagsForUser(const std::string& username,
                                const std::vector<std::string>& flags) = 0;
 
+  typedef base::Callback<void(const std::vector<std::string>& state_keys)>
+      StateKeysCallback;
+
+  // Get the currently valid server-backed state keys for the device.
+  // Server-backed state keys are opaque, device-unique, time-dependent,
+  // client-determined identifiers that are used for keying state in the cloud
+  // for the device to retrieve after a device factory reset.
+  //
+  // The state keys are returned asynchronously via |callback|. The callback
+  // will be invoked with an empty state key vector in case of errors.
+  virtual void GetServerBackedStateKeys(const StateKeysCallback& callback) = 0;
+
   // Creates the instance.
   static SessionManagerClient* Create(DBusClientImplementationType type);