/*

* Copyright (c) 2004 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:    Provides class for authentication with HMAC-SHA1 algorithm.

*

*/

#include "srtpauthentication_rcc.h" 

#include "srtpaesctrcrypto.h"

#include "hash.h"

#include "srtpdef.h"

#include "srtputils.h"

#define DES_AS_8_BIT(str) (TPtrC8((TText8*)((str).Ptr()), (str).Size()))

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

// CSrtpAuthentication_RCC::NewL

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

//

CSrtpAuthentication_RCC* CSrtpAuthentication_RCC::NewL()

    {

    CSrtpAuthentication_RCC* self = CSrtpAuthentication_RCC::NewLC();

    CleanupStack::Pop(self);

    return self;    

    }

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

// CSrtpAuthentication_RCC::NewLC

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

//

CSrtpAuthentication_RCC* CSrtpAuthentication_RCC::NewLC()

    {

    CSrtpAuthentication_RCC* self = new( ELeave ) CSrtpAuthentication_RCC();

    CleanupStack::PushL( self );

    self->ConstructL();

    return self;

    }

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

// SrtpAuthentication_RCC::AuthenticateL

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

//

HBufC8* CSrtpAuthentication_RCC::AuthenticateL(TUint aBitLength,

                                                    const TDesC8& aKey, 

                                                    const TDesC8& aAuthPortion,

                                                    const TDesC8& aRoc)

    {        

    SRTP_DEBUG_DETAIL( "CSrtpAuthentication_RCC::AuthenticateL Entry" );

    TBuf8<20> buf;    

    if (aBitLength != KSRTPAuthTagLength80 )

        {

        SRTP_DEBUG_TUINT_VALUE ("aBitLength is not valid and the length is",aBitLength );

        User::Leave(KErrArgument);

        }

    // reserve size for 160 bit tag which seems to be the default        

	HBufC8* result = HBufC8::NewL(20);  

	TPtr8 ptrOutputBuff = result->Des();	

    CleanupStack::PushL(result);

    if ( !iHmac || !iKey || (*iKey != aKey) )

        {

        CreateHmacL(aKey);

        }

    CleanupStack::Pop(result);

    SRTP_DEBUG_TINT_VALUE( "HMAC INPUT and INPUT Length is ", aAuthPortion.Length());

    SRTP_DEBUG_TINT_VALUE( "HMAC INPUT and INPUT Size is ", aAuthPortion.Size());     

    SRTP_DEBUG_PACKET( DES_AS_8_BIT(aAuthPortion) );    

    if(aRoc.Length())

    	{

  		iHmac->Update(DES_AS_8_BIT(aAuthPortion));

    	buf.Copy(iHmac->Final(DES_AS_8_BIT(aRoc))); 	

    	}

    else

    	{

    	buf.Copy(iHmac->Final(DES_AS_8_BIT(aAuthPortion)));

    	}

    *result = buf;    

    ptrOutputBuff.SetLength(aBitLength/8);

   	SRTP_DEBUG_DETAIL( "HMAC caculated Authentication tag" );

   	SRTP_DEBUG_PACKET( *result );    

    SRTP_DEBUG_DETAIL( "CSrtpAuthentication_RCC::AuthenticateL Exit" );

    return result;            

    }

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

// CSrtpAuthentication_RCC::ConstructL

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

//

void CSrtpAuthentication_RCC::ConstructL()

    {    

    }

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

// CSrtpAuthentication_RCC::~CSrtpAuthentication_RCC

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

//

CSrtpAuthentication_RCC::~CSrtpAuthentication_RCC()

    {    

    delete iHmac;

    delete iKey;

    }

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

// CSrtpAuthentication_RCC::CSrtpAuthentication_RCC

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

//

CSrtpAuthentication_RCC::CSrtpAuthentication_RCC()

    {    

    }

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

// CSrtpAuthentication_RCC::CreateHmacL

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

//

void CSrtpAuthentication_RCC::CreateHmacL(const TDesC8& aKey)

    {

    delete iHmac;

    iHmac = 0;

    delete iKey;

    iKey = 0;

    iKey = aKey.AllocL();

    CSHA1* sha1 = CSHA1::NewL(); 

    CleanupStack::PushL(sha1);

    iHmac = CHMAC::NewL(*iKey, sha1);        

    CleanupStack::Pop(sha1);

    }