/*

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

* All rights reserved.

* This component and the accompanying materials are made available

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

* which accompanies this distribution, and is available

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

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:    implementation

*

*/

#include "tsrtpstreaminstateuninit.h"

#include "msrtpstreamincontext.h"

#include "msrtpcryptohandlercontext.h"

#include "msrtpcryptohandlercontextrtp.h"

#include "msrtpcryptohandlercontextrtcp.h"

#include "srtputils.h"

// ----------------------------------------------------------------------------

// TSRTPStreamInStateUninit::TSRTPStreamInStateUninit

// ----------------------------------------------------------------------------

//

TSRTPStreamInStateUninit::TSRTPStreamInStateUninit(

    MSRTPStreamInContext& aStreamContext,

    MSRTPCryptoHandlerContextRTP& aCryptoHandlerRTPContext,

    MSRTPCryptoHandlerContextRTCP& aCryptoHandlerRTCPContext)

    : TSRTPStreamInStateBase(aStreamContext,

                            aCryptoHandlerRTPContext, 

                            aCryptoHandlerRTCPContext)

    {

    }

// ----------------------------------------------------------------------------

// TSRTPStreamInStateUninit::DoUnprotectSrtpL

// ----------------------------------------------------------------------------

//		

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

    {    

    SRTP_DEBUG_DETAIL( "TSRTPStreamInStateUninit::DoUnprotectSrtpL entry" );

    // first initialize current encrypted RTP packet..

    iCryptoHandlerRTPContext.InitializeEncryptedPacketL(aPacket);    

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

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

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

    iCryptoHandlerRTPContext.SetReceiver_s_l();

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

    // count the packet index i

    iCryptoHandlerRTPContext.CountReceiverPacketIndexL();

    // check MKI if it is used

    iCryptoHandlerRTPContext.CheckMasterKeyIdentifierL();

    SRTP_DEBUG_DETAIL( "DeriveSessionKeysL" );

    // derive session keys..

    iCryptoHandlerRTPContext.DeriveSessionKeysL();

    // do the replay protection 

    iCryptoHandlerRTPContext.ReplayProtectionL();	

	SRTP_DEBUG_DETAIL("DeriveSessionKeysL" );

    // do the authentication (integrity check)

    iCryptoHandlerRTPContext.AuthenticateL();

   	SRTP_DEBUG_DETAIL("Authenticated");

     // decrypt..

    HBufC8* decryptedPacket = iCryptoHandlerRTPContext.DecryptL();

   	SRTP_DEBUG_DETAIL( "StreamInStateUninit,Decrypted" );

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

    // (in RFC 3711, section 3.3):         

    iCryptoHandlerRTPContext.Update_s_l_and_RocL();

    iCryptoHandlerRTPContext.AddReplayIndex(); 

    // first RTP packet successfully decrypted..

    // session keys derived etc..

    // we can go to normal state

    iStreamContext.ChangeRTPState(MSRTPStreamInContext::ESRTPStreamInNormal);

    SRTP_DEBUG_DETAIL( "StreamInStateUninit, UnprotectRTP Out" );

    // return decrypted RTP packet

    SRTP_DEBUG_DETAIL( "TSRTPStreamInStateUninit::DoUnprotectSrtpL exit" );

    return decryptedPacket;    

    }

// ----------------------------------------------------------------------------

// TSRTPStreamInStateUninit::DoUnprotectSrtcpL

// ----------------------------------------------------------------------------

//		

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

    {

     // first initialize current encrypted RTP packet..

    iCryptoHandlerRTCPContext.InitializeEncryptedPacketL(aPacket);    

    //(in RFC 3711, section 3.4):

    // count the packet index i

    iCryptoHandlerRTCPContext.ReceiverPacketIndexL();

    // check MKI if it is used

    iCryptoHandlerRTCPContext.CheckMasterKeyIdentifierL();

    // derive session keys..

    iCryptoHandlerRTCPContext.DeriveSessionKeysL();

    // do the replay protection 

    iCryptoHandlerRTCPContext.ReplayProtectionL();

    // do the authentication (integrity check)

    iCryptoHandlerRTCPContext.AuthenticateL();

     // decrypt..

    HBufC8* decryptedPacket = iCryptoHandlerRTCPContext.DecryptL();

   	iCryptoHandlerRTCPContext.AddReplayIndex(); 

    // first RTP packet successfully decrypted..

    // session keys derived etc..

    // we can go to normal state

    iStreamContext.ChangeRTCPState(MSRTPStreamInContext::ESRTPStreamInNormal);

    // return decrypted RTP packet

    return decryptedPacket;    

    }