/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

// Original author: ekr@rtfm.com

#ifndef srtpflow_h__

#define srtpflow_h__

#include "mozilla/RefPtr.h"

#include "nsISupportsImpl.h"

#include "srtp.h"

namespace mozilla {

#define SRTP_ICM_MASTER_KEY_LENGTH 16

#define SRTP_ICM_MASTER_SALT_LENGTH 14

#define SRTP_ICM_MAX_MASTER_LEGNTH (SRTP_ICM_MASTER_KEY_LENGTH + SRTP_ICM_MASTER_SALT_LENGTH)

#define SRTP_GCM_MASTER_KEY_LENGTH 32

#define SRTP_GCM_MASTER_SALT_LENGTH 12

#define SRTP_GCM_MAX_MASTER_LEGNTH (SRTP_GCM_MASTER_KEY_LENGTH + SRTP_GCM_MASTER_SALT_LENGTH)

#define SRTP_MIN_KEY_LENGTH SRTP_ICM_MAX_MASTER_LEGNTH 

#define SRTP_MAX_KEY_LENGTH SRTP_GCM_MAX_MASTER_LEGNTH 

// SRTCP requires an auth tag *plus* a 4-byte index-plus-'E'-bit value (see

// RFC 3711)

#define SRTP_MAX_EXPANSION (SRTP_MAX_TRAILER_LEN+4)

class SrtpFlow {

  ~SrtpFlow();

 public:

  static unsigned int KeySize(int cipher_suite);

  static unsigned int SaltSize(int cipher_suite);

  static RefPtr<SrtpFlow> Create(int cipher_suite,

                                          bool inbound,

                                          const void *key,

                                          size_t key_len);

  nsresult ProtectRtp(void *in, int in_len,

                      int max_len, int *out_len);

  nsresult UnprotectRtp(void *in, int in_len,

                        int max_len, int *out_len);

  nsresult ProtectRtcp(void *in, int in_len,

                       int max_len, int *out_len);

  nsresult UnprotectRtcp(void *in, int in_len,

                         int max_len, int *out_len);

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SrtpFlow)

  static void srtp_event_handler(srtp_event_data_t *data);

 private:

  SrtpFlow() : session_(nullptr) {}

  nsresult CheckInputs(bool protect, void *in, int in_len,

                       int max_len, int *out_len);

  static nsresult Init();

  static bool initialized;  // Was libsrtp initialized? Only happens once.

  srtp_t session_;

};

}  // End of namespace

#endif