/*

* 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 an abstract class for authentication (integrity protection)

*

*/

#ifndef __MSRTP_AUTHENTICATION_H__

#define __MSRTP_AUTHENTICATION_H__

#include <e32base.h>

class MSRTPAuthentication

    {

    public:

        /**

        * This function is called by SRTP for authentication/integrity protection

        * to create authentication tag regardless of the algorithm, 

        * the default algorith is HMAC-SHA1.

        * Produces authentication tag based on input key and data M.

        * result IS truncated to n_tag leftmost bits

        * @param aBitLength  authentication tag length, 32 or 80 bits

        * @param aKey  authentication key (n_a)

        * @param aAuthPortion data to be integrity protected 

        * @param aRoc packet ROC 

	    * Returns HBufC8* authentication tag (untruncated) 

        */

        virtual HBufC8* AuthenticateL(TUint aBitLength,

                                    const TDesC8& aKey, 

                                    const TDesC8& aAuthPortion,

                                    const TDesC8& aRoc) = 0;

        virtual ~MSRTPAuthentication() { };                                

    };

#endif // __MSRTP_AUTHENTICATION_H__