media/mtransport/SrtpFlow.h
author Lina Cambridge <lina@yakshaving.ninja>
Tue, 02 Apr 2019 18:49:21 +0000
changeset 467645 db20a3f4324ec9fc29bb21bda77672e7e7640529
parent 448966 6f3709b3878117466168c40affa7bca0b60cf75b
child 472073 e1993a1f09ac53cd1a04fdf6a87f8cad8e44f73e
permissions -rw-r--r--
Bug 1539104 - Add a way to detect supported storage connection operations. r=mak In retrospect, overloading `Connection::connectionReady` to mean "is ready _and_ supports this operation" wasn't a good idea. This commit reverts that change (cfd44c936a9b), and adds two new methods: * `Connection::operationSupported`, to check if a connection supports sync or async operations. This method is public. * `Connection::ensureOperationSupported`, that asserts or returns an error if the connection doesn't support an operation. This is private. `operationSupported` is used by callers like `Service::minimizeMemory` to detect if the connection supports sync operations, since both sync and async connections implement `mozIStorageConnection` now. Finally, some callers used `!mDBConn` to check if the connection was ready, while others used `connectionReady()`. This commit changes them to use the latter. Differential Revision: https://phabricator.services.mozilla.com/D24974

/* 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_LENGTH \
  (SRTP_ICM_MASTER_KEY_LENGTH + SRTP_ICM_MASTER_SALT_LENGTH)

#define SRTP_GCM_MASTER_KEY_MIN_LENGTH 16
#define SRTP_GCM_MASTER_KEY_MAX_LENGTH 32
#define SRTP_GCM_MASTER_SALT_LENGTH 12

#define SRTP_GCM_MIN_MASTER_LENGTH \
  (SRTP_GCM_MASTER_KEY_MIN_LENGTH + SRTP_GCM_MASTER_SALT_LENGTH)
#define SRTP_GCM_MAX_MASTER_LENGTH \
  (SRTP_GCM_MASTER_KEY_MAX_LENGTH + SRTP_GCM_MASTER_SALT_LENGTH)

#define SRTP_MIN_KEY_LENGTH SRTP_GCM_MIN_MASTER_LENGTH
#define SRTP_MAX_KEY_LENGTH SRTP_GCM_MAX_MASTER_LENGTH

// 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_;
};

}  // namespace mozilla
#endif