/*

* 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.

*

*/

#ifndef __SRTP_AUTHENTICATION_HMAC_SHA1_H__

#define __SRTP_AUTHENTICATION_HMAC_SHA1_H__

#include "msrtpauthentication.h"

class CHMAC;

class CSRTPAuthentication_HMAC_SHA1 : public CBase, public MSRTPAuthentication

    {

    public:

        /**

        * Constructor.

        * @leave KErrNone if success, system-wide error code otherwise

        */

	    static CSRTPAuthentication_HMAC_SHA1* NewL();

        /**

        * Constructor.

        * @leave KErrNone if success, system-wide error code otherwise

        */

	    static CSRTPAuthentication_HMAC_SHA1* NewLC();

        /**

        * Destructor.

        */

	    ~CSRTPAuthentication_HMAC_SHA1();

        /**

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

        * with the default algorith, 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

        * @param aKey  authentication key (n_a)

        * @param aAuthPortion data to be integrity protected 

	    * Returns HBufC8* authentication tag (n_tag truncated) 

        */

        HBufC8* AuthenticateL(TUint aBitLength,

                            const TDesC8& aKey, 

                            const TDesC8& aAuthPortion,

                            const TDesC8& aRoc);

    private:         // methods

        /**

        * Default constructor.

        */

        CSRTPAuthentication_HMAC_SHA1();  

        void ConstructL();  

        void CreateHmacL(const TDesC8& aKey);

    private: // data

        HBufC8* iKey;

        CHMAC* iHmac;

    };

#endif // __SRTP_AUTHENTICATION_HMAC_SHA1_H__