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 

    21 #include "tsrtpstreaminstatenormal.h"

    22 #include "msrtpstreamincontext.h"

    23 #include "msrtpcryptohandlercontext.h"

    24 #include "msrtpcryptohandlercontextrtp.h"

    25 #include "msrtpcryptohandlercontextrtcp.h"

    26 #include "srtputils.h"

    27 

    28 // ----------------------------------------------------------------------------

    29 // TSRTPStreamInStateNormal::TSRTPStreamInStateNormal

    30 // ----------------------------------------------------------------------------

    31 //

    32 TSRTPStreamInStateNormal::TSRTPStreamInStateNormal(

    33     MSRTPStreamInContext& aStreamContext,

    34     MSRTPCryptoHandlerContextRTP& aCryptoHandlerRTPContext,

    35     MSRTPCryptoHandlerContextRTCP& aCryptoHandlerRTCPContext)

    36     : TSRTPStreamInStateBase(aStreamContext,

    37                             aCryptoHandlerRTPContext, 

    38                             aCryptoHandlerRTCPContext)

    39     {

    40     }

    41 

    42 // ----------------------------------------------------------------------------

    43 // TSRTPStreamInStateNormal::DoUnprotectSrtpL

    44 // ----------------------------------------------------------------------------

    45 //		

    46 HBufC8* TSRTPStreamInStateNormal::DoUnprotectSrtpL(const TDesC8& aPacket)

    47     {

    48 	SRTP_DEBUG_DETAIL( "TSRTPStreamInStateNormal::DoUnprotectSrtpL ENTRY" );

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

    50           

    51     // first initialize current encrypted RTP packet..

    52     iCryptoHandlerRTPContext.InitializeEncryptedPacketL(aPacket);    

    53            

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

    55     // count the packet index i

    56     iCryptoHandlerRTPContext.CountReceiverPacketIndexL();

    57      

    58     // check MKI if it is used

    59     iCryptoHandlerRTPContext.CheckMasterKeyIdentifierL();

    60      

    61     // derive session keys..

    62     if (iCryptoHandlerRTPContext.MasterKeysUpdated())

    63         {

    64         iCryptoHandlerRTPContext.DeriveSessionKeysL();        

    65         }

    66 

    67     // do the replay protection 

    68     iCryptoHandlerRTPContext.ReplayProtectionL();

    69 

    70     // do the authentication (integrity check)

    71     iCryptoHandlerRTPContext.AuthenticateL();

    72                

    73      // decrypt..

    74     HBufC8* decryptedPacket = iCryptoHandlerRTPContext.DecryptL();

    75      

    76     // Step 7, conditional update s_l and ROC values..

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

    78     iCryptoHandlerRTPContext.Update_s_l_and_RocL();

    79     iCryptoHandlerRTPContext.AddReplayIndex();

    80     ///Should check the next Packet Index and decide if need to be re-key

    81     

    82     SRTP_DEBUG_TINT_VALUE( "the decrypted packet Length is", decryptedPacket->Length());

    83     SRTP_DEBUG_DETAIL( "TSRTPStreamInStateNormal::DoUnprotectSrtpL EXIT" );

    84 	

    85     return decryptedPacket;    

    86     

    87     }

    88 

    89 // ----------------------------------------------------------------------------

    90 // TSRTPStreamInStateNormal::DoUnprotectSrtcpL

    91 // ----------------------------------------------------------------------------

    92 //		

    93 HBufC8* TSRTPStreamInStateNormal::DoUnprotectSrtcpL(const TDesC8& aPacket)

    94     {

    95     

    96     // first initialize current encrypted RTP packet..

    97     iCryptoHandlerRTCPContext.InitializeEncryptedPacketL(aPacket);    

    98            

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

   100     // count the packet index i

   101     iCryptoHandlerRTCPContext.ReceiverPacketIndexL();

   102      

   103     // check MKI if it is used

   104     iCryptoHandlerRTCPContext.CheckMasterKeyIdentifierL();

   105      

   106     // derive session keys..

   107     if (iCryptoHandlerRTCPContext.MasterKeysUpdated())

   108         {

   109         iCryptoHandlerRTCPContext.DeriveSessionKeysL();        

   110         }

   111 

   112     // do the replay protection 

   113     iCryptoHandlerRTCPContext.ReplayProtectionL();

   114 

   115     // do the authentication (integrity check)

   116     iCryptoHandlerRTCPContext.AuthenticateL();

   117                

   118      // decrypt..

   119     HBufC8* decryptedPacket = iCryptoHandlerRTCPContext.DecryptL();

   120     iCryptoHandlerRTCPContext.AddReplayIndex();  

   121     ///Should check the next Packet Index and decide if need to be re-key

   122     //Set updateKey needed and then lateron compared the key if the key is the same then ignore packet

   123     //implemented later

   124     // return decrypted RTCP packet

   125     return decryptedPacket;    

   126     

   127     }