talk/app/webrtc/dtlsidentitystore.h

/*
 * libjingle
 * Copyright 2015 Google Inc.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 */

#ifndef TALK_APP_WEBRTC_DTLSIDENTITYSTORE_H_
#define TALK_APP_WEBRTC_DTLSIDENTITYSTORE_H_

#include <queue>
#include <string>

#include "webrtc/base/messagehandler.h"
#include "webrtc/base/messagequeue.h"
#include "webrtc/base/refcount.h"
#include "webrtc/base/scoped_ptr.h"
#include "webrtc/base/scoped_ref_ptr.h"
#include "webrtc/base/sslidentity.h"
#include "webrtc/base/thread.h"

namespace webrtc {
class SSLIdentity;
class Thread;

// Used to receive callbacks of DTLS identity requests.
class DTLSIdentityRequestObserver : public rtc::RefCountInterface {
 public:
  virtual void OnFailure(int error) = 0;
  // TODO(jiayl): Unify the OnSuccess method once Chrome code is updated.
  virtual void OnSuccess(const std::string& der_cert,
                         const std::string& der_private_key) = 0;
  // |identity| is a scoped_ptr because rtc::SSLIdentity is not copyable and the
  // client has to get the ownership of the object to make use of it.
  virtual void OnSuccessWithIdentityObj(
      rtc::scoped_ptr<rtc::SSLIdentity> identity) = 0;

 protected:
  virtual ~DTLSIdentityRequestObserver() {}
};

// TODO(hbos): To replace DTLSIdentityRequestObserver.
// Used to receive callbacks of DTLS identity requests.
class DtlsIdentityRequestObserver : public rtc::RefCountInterface {
 public:
  virtual void OnFailure(int error) = 0;
  // TODO(hbos): Unify the OnSuccess method once Chrome code is updated.
  virtual void OnSuccess(const std::string& der_cert,
                         const std::string& der_private_key) = 0;
  // |identity| is a scoped_ptr because rtc::SSLIdentity is not copyable and the
  // client has to get the ownership of the object to make use of it.
  virtual void OnSuccess(rtc::scoped_ptr<rtc::SSLIdentity> identity) = 0;

 protected:
  virtual ~DtlsIdentityRequestObserver() {}
};

// TODO(hbos): To be implemented.
// This interface defines an in-memory DTLS identity store, which generates DTLS
// identities.
// APIs calls must be made on the signaling thread and the callbacks are also
// called on the signaling thread.
class DtlsIdentityStoreInterface {
 public:
  virtual ~DtlsIdentityStoreInterface() { }

  virtual void RequestIdentity(
      rtc::KeyType key_type,
      const rtc::scoped_refptr<DtlsIdentityRequestObserver>& observer) = 0;
};

// This class implements an in-memory DTLS identity store, which generates the
// DTLS identity on the worker thread.
// APIs calls must be made on the signaling thread and the callbacks are also
// called on the signaling thread.
class DtlsIdentityStore : public rtc::MessageHandler {
 public:
  static const char kIdentityName[];

  DtlsIdentityStore(rtc::Thread* signaling_thread,
                    rtc::Thread* worker_thread);
  virtual ~DtlsIdentityStore();

  // Initialize will start generating the free identity in the background.
  void Initialize();

  // The |observer| will be called when the requested identity is ready, or when
  // identity generation fails.
  void RequestIdentity(webrtc::DTLSIdentityRequestObserver* observer);

  // rtc::MessageHandler override;
  void OnMessage(rtc::Message* msg) override;

  // Returns true if there is a free identity, used for unit tests.
  bool HasFreeIdentityForTesting() const;

 private:
  sigslot::signal0<> SignalDestroyed;
  class WorkerTask;
  typedef rtc::ScopedMessageData<DtlsIdentityStore::WorkerTask>
      IdentityTaskMessageData;

  void GenerateIdentity();
  void OnIdentityGenerated(rtc::scoped_ptr<rtc::SSLIdentity> identity);
  void ReturnIdentity(rtc::scoped_ptr<rtc::SSLIdentity> identity);

  void PostGenerateIdentityResult_w(rtc::scoped_ptr<rtc::SSLIdentity> identity);

  rtc::Thread* const signaling_thread_;
  rtc::Thread* const worker_thread_;

  // These members should be accessed on the signaling thread only.
  int pending_jobs_;
  rtc::scoped_ptr<rtc::SSLIdentity> free_identity_;
  typedef std::queue<rtc::scoped_refptr<webrtc::DTLSIdentityRequestObserver>>
      ObserverList;
  ObserverList pending_observers_;
};

}  // namespace webrtc

#endif  // TALK_APP_WEBRTC_DTLSIDENTITYSTORE_H_