Handle pairing_client_id in the negotiating authenticators.

remoting/protocol/pairing_client_authenticator.cc

 // Copyright 2013 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 "remoting/protocol/pairing_client_authenticator.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "remoting/base/constants.h"
 #include "remoting/protocol/auth_util.h"
 #include "remoting/protocol/channel_authenticator.h"
 #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
 
 namespace remoting {
 namespace protocol {
 
 PairingClientAuthenticator::PairingClientAuthenticator(
     const ClientAuthenticationConfig& client_auth_config,
     const CreateBaseAuthenticatorCallback& create_base_authenticator_callback)
     : client_auth_config_(client_auth_config),
       create_base_authenticator_callback_(create_base_authenticator_callback),
-      weak_factory_(this) {
-  spake2_authenticator_ = create_base_authenticator_callback_.Run(
-      client_auth_config.pairing_secret, MESSAGE_READY);
-  using_paired_secret_ = true;
+      weak_factory_(this) {}
+
+PairingClientAuthenticator::~PairingClientAuthenticator() {}
+
+void PairingClientAuthenticator::Start(State initial_state,
+                                       const base::Closure& resume_callback) {
+  if (client_auth_config_.pairing_client_id.empty() ||
+      client_auth_config_.pairing_secret.empty()) {
+    error_message_ = "not-paired";

[Jamie, 2016/03/17 00:36:22]

It's not obvious why this needs to be set here (ie, nothing has gone wrong yet).
I think a comment would help.

[Sergey Ulanov, 2016/03/17 00:49:21]

Done.

+    using_paired_secret_ = false;
+    CreateSpakeAuthenticatorWithPin(initial_state, resume_callback);
+  } else {
+    StartPaired(initial_state);
+    resume_callback.Run();
+  }
 }
 
-PairingClientAuthenticator::~PairingClientAuthenticator() {}
+void PairingClientAuthenticator::StartPaired(State initial_state) {
+  DCHECK(!client_auth_config_.pairing_client_id.empty());
+  DCHECK(!client_auth_config_.pairing_secret.empty());
+
+  using_paired_secret_ = true;
+  spake2_authenticator_ = create_base_authenticator_callback_.Run(
+      client_auth_config_.pairing_secret, initial_state);
+}
 
 Authenticator::State PairingClientAuthenticator::state() const {
   if (waiting_for_pin_)
     return PROCESSING_MESSAGE;
   return PairingAuthenticatorBase::state();
 }
 
 void PairingClientAuthenticator::CreateSpakeAuthenticatorWithPin(
     State initial_state,
     const base::Closure& resume_callback) {
   DCHECK(!waiting_for_pin_);
   waiting_for_pin_ = true;
   client_auth_config_.fetch_secret_callback.Run(
       true,
       base::Bind(&PairingClientAuthenticator::OnPinFetched,
                  weak_factory_.GetWeakPtr(), initial_state, resume_callback));
 }
 
-void PairingClientAuthenticator::AddPairingElements(buzz::XmlElement* message) {
-  // If the client id and secret have not yet been sent, do so now. Note that
-  // in this case the V2Authenticator is being used optimistically to send the
-  // first message of the SPAKE exchange since we don't yet know whether or not
-  // the host will accept the client id or request that we fall back to the PIN.
-  if (!sent_client_id_) {
-    buzz::XmlElement* pairing_tag = new buzz::XmlElement(kPairingInfoTag);
-    pairing_tag->AddAttr(kClientIdAttribute,
-                         client_auth_config_.pairing_client_id);
-    message->AddElement(pairing_tag);
-    sent_client_id_ = true;
-  }
-}
-
 void PairingClientAuthenticator::OnPinFetched(
     State initial_state,
     const base::Closure& resume_callback,
     const std::string& pin) {
   DCHECK(waiting_for_pin_);
   DCHECK(!spake2_authenticator_);
   waiting_for_pin_ = false;
   spake2_authenticator_ = create_base_authenticator_callback_.Run(
       GetSharedSecretHash(client_auth_config_.host_id, pin), initial_state);
   resume_callback.Run();
 }
 
 }  // namespace protocol
 }  // namespace remoting