Third Party authentication protocol.

remoting/protocol/third_party_authenticator_base.h

+// 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.
+
+#ifndef REMOTING_PROTOCOL_THIRD_PARTY_AUTHENTICATOR_BASE_H_
+#define REMOTING_PROTOCOL_THIRD_PARTY_AUTHENTICATOR_BASE_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "googleurl/src/gurl.h"
+#include "remoting/protocol/authenticator.h"
+#include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
+
+namespace remoting {
+
+class RsaKeyPair;
+
+namespace protocol {
+
+// Implements an authentication method that relies on a third party server for

[Sergey Ulanov, 2013/03/07 21:20:41]

Update comments?

+// authentication of both client and host.
+// When third party authentication is being used, the client must request both a
+// token and a shared secret from a third-party server (which may require the
+// user to authenticate themselves). The client then sends only the token to the
+// host. The host signs the token, then contacts the third-party server to
+// exchange the token for the shared secret. Once both client and host have the
+// shared secret, they use an underlying |V2Authenticator| (SPAKE2) to negotiate
+// an authentication key, which is used to establish the connection.
+class ThirdPartyAuthenticatorBase : public Authenticator {
+ public:
+  // XML tag names for third party authentication fields.

[Sergey Ulanov, 2013/03/07 21:20:41]

Do they need to be public?

+  static const buzz::StaticQName kTokenUrlTag;
+  static const buzz::StaticQName kTokenScopeTag;
+  static const buzz::StaticQName kTokenTag;
+
+  virtual ~ThirdPartyAuthenticatorBase();
+
+  // Authenticator interface.
+  virtual State state() const OVERRIDE;
+  virtual RejectionReason rejection_reason() const OVERRIDE;
+  virtual void ProcessMessage(const buzz::XmlElement* message,
+                              const base::Closure& resume_callback) OVERRIDE;
+  virtual scoped_ptr<buzz::XmlElement> GetNextMessage() OVERRIDE;
+  virtual scoped_ptr<ChannelAuthenticator>
+      CreateChannelAuthenticator() const OVERRIDE;
+
+ protected:
+  explicit ThirdPartyAuthenticatorBase(State initial_state);
+  void ProcessUnderlyingMessage(
+      const buzz::XmlElement* message,
+      const base::Closure& resume_callback);
+  virtual void ProcessMessageInternal(
+      const buzz::XmlElement* message,
+      const base::Closure& resume_callback) = 0;
+  virtual void GetNextMessageInternal(buzz::XmlElement* message) = 0;
+
+  // Used for both host and client authenticators.
+  scoped_ptr<Authenticator> underlying_;
+  State state_;
+  RejectionReason rejection_reason_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ThirdPartyAuthenticatorBase);
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_THIRD_PARTY_AUTHENTICATOR_BASE_H_