1 /*

     2 * Copyright (c) 2005 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:    implementation

    15 *

    16 */

    17 

    18 

    19 

    20 #include "tsrtpstreaminstateuninit.h"

    21 #include "msrtpstreamincontext.h"

    22 #include "msrtpcryptohandlercontext.h"

    23 #include "msrtpcryptohandlercontextrtp.h"

    24 #include "msrtpcryptohandlercontextrtcp.h"

    25 #include "srtputils.h"

    26 

    27 // ----------------------------------------------------------------------------

    28 // TSRTPStreamInStateUninit::TSRTPStreamInStateUninit

    29 // ----------------------------------------------------------------------------

    30 //

    31 TSRTPStreamInStateUninit::TSRTPStreamInStateUninit(

    32     MSRTPStreamInContext& aStreamContext,

    33     MSRTPCryptoHandlerContextRTP& aCryptoHandlerRTPContext,

    34     MSRTPCryptoHandlerContextRTCP& aCryptoHandlerRTCPContext)

    35     : TSRTPStreamInStateBase(aStreamContext,

    36                             aCryptoHandlerRTPContext, 

    37                             aCryptoHandlerRTCPContext)

    38     {

    39     }

    40 

    41 // ----------------------------------------------------------------------------

    42 // TSRTPStreamInStateUninit::DoUnprotectSrtpL

    43 // ----------------------------------------------------------------------------

    44 //		

    45 HBufC8* TSRTPStreamInStateUninit::DoUnprotectSrtpL(const TDesC8& aPacket)

    46     {    

    47     SRTP_DEBUG_DETAIL( "TSRTPStreamInStateUninit::DoUnprotectSrtpL entry" );

    48     // first initialize current encrypted RTP packet..

    49     iCryptoHandlerRTPContext.InitializeEncryptedPacketL(aPacket);    

    50    

    51     SRTP_DEBUG_TINT_VALUE("Encrypted PacketLength is", aPacket.Length() );                

    52              

    53     // for the first RTP packet, we need to set 

    54     // receiver s_l value to current sequence number, see RFC

    55     iCryptoHandlerRTPContext.SetReceiver_s_l();

    56        

    57     // Step 2 (in RFC 3711, section 3.3):

    58     // count the packet index i

    59     iCryptoHandlerRTPContext.CountReceiverPacketIndexL();

    60      

    61     // check MKI if it is used

    62     iCryptoHandlerRTPContext.CheckMasterKeyIdentifierL();

    63     SRTP_DEBUG_DETAIL( "DeriveSessionKeysL" );

    64                

    65     // derive session keys..

    66     iCryptoHandlerRTPContext.DeriveSessionKeysL();

    67 

    68     // do the replay protection 

    69     iCryptoHandlerRTPContext.ReplayProtectionL();	

    70     

    71 	SRTP_DEBUG_DETAIL("DeriveSessionKeysL" );

    72     

    73     // do the authentication (integrity check)

    74     iCryptoHandlerRTPContext.AuthenticateL();

    75    	SRTP_DEBUG_DETAIL("Authenticated");

    76                

    77      // decrypt..

    78     HBufC8* decryptedPacket = iCryptoHandlerRTPContext.DecryptL();

    79    	SRTP_DEBUG_DETAIL( "StreamInStateUninit,Decrypted" );

    80      

    81     // Step 6, conditional update s_l and ROC values..

    82     // (in RFC 3711, section 3.3):         

    83     iCryptoHandlerRTPContext.Update_s_l_and_RocL();

    84     iCryptoHandlerRTPContext.AddReplayIndex(); 

    85     // first RTP packet successfully decrypted..

    86     // session keys derived etc..

    87     // we can go to normal state

    88     iStreamContext.ChangeRTPState(MSRTPStreamInContext::ESRTPStreamInNormal);

    89     

    90     

    91     SRTP_DEBUG_DETAIL( "StreamInStateUninit, UnprotectRTP Out" );

    92     

    93     // return decrypted RTP packet

    94     SRTP_DEBUG_DETAIL( "TSRTPStreamInStateUninit::DoUnprotectSrtpL exit" );

    95     

    96     return decryptedPacket;    

    97     }

    98 

    99 // ----------------------------------------------------------------------------

   100 // TSRTPStreamInStateUninit::DoUnprotectSrtcpL

   101 // ----------------------------------------------------------------------------

   102 //		

   103 HBufC8* TSRTPStreamInStateUninit::DoUnprotectSrtcpL(const TDesC8& aPacket)

   104     {

   105      // first initialize current encrypted RTP packet..

   106     iCryptoHandlerRTCPContext.InitializeEncryptedPacketL(aPacket);    

   107     

   108     

   109     //(in RFC 3711, section 3.4):

   110     // count the packet index i

   111     iCryptoHandlerRTCPContext.ReceiverPacketIndexL();

   112      

   113     // check MKI if it is used

   114     iCryptoHandlerRTCPContext.CheckMasterKeyIdentifierL();

   115      

   116     // derive session keys..

   117     iCryptoHandlerRTCPContext.DeriveSessionKeysL();

   118 

   119     // do the replay protection 

   120     iCryptoHandlerRTCPContext.ReplayProtectionL();

   121 

   122     // do the authentication (integrity check)

   123     iCryptoHandlerRTCPContext.AuthenticateL();

   124                

   125      // decrypt..

   126     HBufC8* decryptedPacket = iCryptoHandlerRTCPContext.DecryptL();

   127      

   128    	iCryptoHandlerRTCPContext.AddReplayIndex(); 

   129     // first RTP packet successfully decrypted..

   130     // session keys derived etc..

   131     // we can go to normal state

   132     iStreamContext.ChangeRTCPState(MSRTPStreamInContext::ESRTPStreamInNormal);

   133     

   134     

   135     // return decrypted RTP packet

   136     return decryptedPacket;    

   137     }