ccRTP
CryptoContextCtrl.h
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1 /*
2  Copyright (C) 2004-2006 the Minisip Team
3  Copyright (C) 2011 Werner Dittmann for the SRTCP support
4 
5  This library is free software; you can redistribute it and/or
6  modify it under the terms of the GNU Lesser General Public
7  License as published by the Free Software Foundation; either
8  version 2.1 of the License, or (at your option) any later version.
9 
10  This library is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Lesser General Public License for more details.
14 
15  You should have received a copy of the GNU Lesser General Public License
16  along with GNU ccRTP. If not, see <http://www.gnu.org/licenses/>.
17 */
18 
19 
20 
21 #ifndef CRYPTOCONTEXTCTRL_H
22 #define CRYPTOCONTEXTCTRL_H
23 
24 #include <commoncpp/config.h>
25 
26 #define REPLAY_WINDOW_SIZE 64
27 
28 #ifdef SRTP_SUPPORT
29 #include <ccrtp/crypto/SrtpSymCrypto.h>
30 #endif
31 
32 NAMESPACE_COMMONCPP
33 
61  class __EXPORT CryptoContextCtrl {
62  public:
72  CryptoContextCtrl( uint32 ssrc );
73 
139  CryptoContextCtrl( uint32 ssrc,
140  const int32 ealg,
141  const int32 aalg,
142  uint8* masterKey,
143  int32 masterKeyLength,
144  uint8* masterSalt,
145  int32 masterSaltLength,
146  int32 ekeyl,
147  int32 akeyl,
148  int32 skeyl,
149  int32 tagLength );
156 
173  void srtcpEncrypt( uint8* rtp, size_t len, uint64 index, uint32 ssrc );
174 
191  void srtcpAuthenticate(uint8* rtp, size_t len, uint32 roc, uint8* tag );
192 
205 
221  bool checkReplay(uint32 newSeqNumber);
222 
232  void update( uint32 newSeqNumber );
233 
239  inline int32
240  getTagLength() const
241  {return tagLength;}
242 
243 
249  inline int32
250  getMkiLength() const
251  {return mkiLength;}
252 
258  inline uint32
259  getSsrc() const
260  {return ssrcCtx;}
261 
284 
285  private:
286 
287  uint32 ssrcCtx;
288  bool using_mki;
289  uint32 mkiLength;
290  uint8* mki;
291 
292  uint32 s_l;
293 
294  /* bitmask for replay check */
295  uint64 replay_window;
296 
297  uint8* master_key;
298  uint32 master_key_length;
299  uint8* master_salt;
300  uint32 master_salt_length;
301 
302  /* Session Encryption, Authentication keys, Salt */
303  int32 n_e;
304  uint8* k_e;
305  int32 n_a;
306  uint8* k_a;
307  int32 n_s;
308  uint8* k_s;
309 
310  int32 ealg;
311  int32 aalg;
312  int32 ekeyl;
313  int32 akeyl;
314  int32 skeyl;
315  int32 tagLength;
316 
317  void* macCtx;
318 
319 #ifdef SRTP_SUPPORT
320  SrtpSymCrypto* cipher;
321  SrtpSymCrypto* f8Cipher;
322 #else
323  void* cipher;
324  void* f8Cipher;
325 #endif
326 
327  };
328 
329 END_NAMESPACE
330 
331 #endif
332 
The implementation for a SRTCP cryptographic context.
Definition: CryptoContextCtrl.h:61
CryptoContextCtrl(uint32 ssrc)
Constructor for empty SRTP cryptographic context.
bool checkReplay(uint32 newSeqNumber)
Check for packet replay.
void deriveSrtcpKeys()
Perform key derivation according to SRTP specification.
int32 getTagLength() const
Get the length of the SRTP authentication tag in bytes.
Definition: CryptoContextCtrl.h:240
uint32 getSsrc() const
Get the SSRC of this SRTP Cryptograhic context.
Definition: CryptoContextCtrl.h:259
int32 getMkiLength() const
Get the length of the MKI in bytes.
Definition: CryptoContextCtrl.h:250
~CryptoContextCtrl()
Destructor.
void update(uint32 newSeqNumber)
Update the SRTP packet index.
CryptoContextCtrl(uint32 ssrc, const int32 ealg, const int32 aalg, uint8 *masterKey, int32 masterKeyLength, uint8 *masterSalt, int32 masterSaltLength, int32 ekeyl, int32 akeyl, int32 skeyl, int32 tagLength)
Constructor for an active SRTP cryptographic context.
void srtcpAuthenticate(uint8 *rtp, size_t len, uint32 roc, uint8 *tag)
Compute the authentication tag.
CryptoContextCtrl * newCryptoContextForSSRC(uint32 ssrc)
Derive a new Crypto Context for use with a new SSRC.
void srtcpEncrypt(uint8 *rtp, size_t len, uint64 index, uint32 ssrc)
Perform SRTP encryption.