/*

* 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 AES CM 128 bit key derivation

*

*/

#ifndef __SRTP_KEYDERIVATION_AESCM128_H__

#define __SRTP_KEYDERIVATION_AESCM128_H__

#include "msrtpkeyderivation.h"

//FORWARD declarations

class CSrtpAESCTRCrypto;

class CSRTPKeyDerivation_AESCM128 : public CBase, public MSRTPKeyDerivation

    {

    public:

        /**

        * Constructor.

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

        */

	    static CSRTPKeyDerivation_AESCM128* NewL();

        /**

        * Constructor.

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

        */

	    static CSRTPKeyDerivation_AESCM128* NewLC();

        /**

        * Destructor.

        */

	    ~CSRTPKeyDerivation_AESCM128();

        /**

        * This function is called by SRTP for key derivation operation (PRF_n)

        * with the default algorithm AESCM-128

        * Produces keystream based on input key and IV value.

        * PRF_n function is used to derive session key from desired master key.

        * @param aBitLength  bit length of the key.

        * @param aKey  Input key.

        * @param aIV  Integer Value (IV).

	    * Returns HBufC8* keystream 

        */

        HBufC8* PRF_128BitL(TUint aBitLength, 

                         const TDesC8& aKey, 

                         const TDesC8& aIV);

    private:         // Data        

	    CSrtpAESCTRCrypto* iEncryptor;	    

    private:         // methods

        /**

        * Default constructor.

        */

        CSRTPKeyDerivation_AESCM128();  

        void ConstructL();  

    };

#endif // __SRTP_KEYDERIVATION_AESCM128_H__