components/proximity_auth/client.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_PROXIMITY_AUTH_CLIENT_H
   6 #define COMPONENTS_PROXIMITY_AUTH_CLIENT_H
   7
   8 #include <deque>
   9
  10 #include "base/macros.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/observer_list.h"
  13 #include "components/proximity_auth/connection_observer.h"
  14
  15 namespace base {
  16 class DictionaryValue;
  17 }
  18
  19 namespace proximity_auth {
  20
  21 class ClientObserver;
  22 class Connection;
  23 class SecureContext;
  24
  25 // A client handling the Easy Unlock protocol, capable of parsing events from
  26 // the remote device and sending events for the local device.
  27 class Client : public ConnectionObserver {
  28  public:
  29   // Constructs a client that sends and receives messages over the given
  30   // |connection|, using the |secure_context| to encrypt and decrypt the
  31   // messages. The |connection| must be connected. The client begins observing
  32   // messages as soon as it is constructed.
  33   Client(scoped_ptr<Connection> connection,
  34          scoped_ptr<SecureContext> secure_context);
  35   virtual ~Client();
  36
  37   // Adds or removes an observer for Client events.
  38   void AddObserver(ClientObserver* observer);
  39   void RemoveObserver(ClientObserver* observer);
  40
  41   // Returns true iff the remote device supports the v3.1 sign-in protocol.
  42   bool SupportsSignIn() const;
  43
  44   // Sends an unlock event message to the remote device.
  45   void DispatchUnlockEvent();
  46
  47   // Sends a serialized SecureMessage to the remote device to decrypt the
  48   // |challenge|. OnDecryptResponse will be called for each observer when the
  49   // decrypted response is received.
  50   // TODO(isherman): Add params for the RSA private key and crypto delegate.
  51   void RequestDecryption(const std::string& challenge);
  52
  53   // Sends a simple request to the remote device to unlock the screen.
  54   // OnUnlockResponse is called for each observer when the response is returned.
  55   void RequestUnlock();
  56
  57  protected:
  58   // Exposed for testing.
  59   Connection* connection() { return connection_.get(); }
  60   SecureContext* secure_context() { return secure_context_.get(); }
  61
  62  private:
  63   // Internal data structure to represent a pending message that either hasn't
  64   // been sent yet or is waiting for a response from the remote device.
  65   struct PendingMessage {
  66     PendingMessage();
  67     PendingMessage(const base::DictionaryValue& message);
  68     ~PendingMessage();
  69
  70     // The message, serialized as JSON.
  71     const std::string json_message;
  72
  73     // The message type. This is possible to parse from the |json_message|; it's
  74     // stored redundantly for convenience.
  75     const std::string type;
  76   };
  77
  78   // Pops the first of the |queued_messages_| and sends it to the remote device.
  79   void ProcessMessageQueue();
  80
  81   // Handles an incoming "status_update" |message|, parsing and notifying
  82   // observers of the content.
  83   void HandleRemoteStatusUpdateMessage(const base::DictionaryValue& message);
  84
  85   // Handles an incoming "decrypt_response" message, parsing and notifying
  86   // observers of the decrypted content.
  87   void HandleDecryptResponseMessage(const base::DictionaryValue& message);
  88
  89   // Handles an incoming "unlock_response" message, notifying observers of the
  90   // response.
  91   void HandleUnlockResponseMessage(const base::DictionaryValue& message);
  92
  93   // ConnectionObserver:
  94   void OnConnectionStatusChanged(Connection* connection,
  95                                  Connection::Status old_status,
  96                                  Connection::Status new_status) override;
  97   void OnMessageReceived(const Connection& connection,
  98                          const WireMessage& wire_message) override;
  99   void OnSendCompleted(const Connection& connection,
 100                        const WireMessage& wire_message,
 101                        bool success) override;
 102
 103   // The connection used to send and receive events and status updates.
 104   scoped_ptr<Connection> connection_;
 105
 106   // Used to encrypt and decrypt payloads sent and received over the
 107   // |connection_|.
 108   scoped_ptr<SecureContext> secure_context_;
 109
 110   // The registered observers of |this_| client.
 111   ObserverList<ClientObserver> observers_;
 112
 113   // Queue of messages to send to the remote device.
 114   std::deque<PendingMessage> queued_messages_;
 115
 116   // The current message being sent or waiting on the remote device for a
 117   // response. Null if there is no message currently in this state.
 118   scoped_ptr<PendingMessage> pending_message_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(Client);
 121 };
 122
 123 }  // namespace proximity_auth
 124
 125 #endif  // COMPONENTS_PROXIMITY_AUTH_CLIENT_H