/*

* Copyright (c) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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: 

* Cipher MAC plugin implementation

*

*/

/**

 @file

 @internalComponent

 @released

*/

#ifndef __CRYPTOAPI_SOFTWARECIPHERMACIMPL_H__

#define __CRYPTOAPI_SOFTWARECIPHERMACIMPL_H__

#include <cryptospi/cryptosymmetriccipherapi.h>

#include <cryptospi/keys.h>

namespace SoftwareCrypto

	{

	using namespace CryptoSpi;

	/**

	 * This is the maximum block size in bytes currently supported by CMAC implementation.

	 * 

	 * The cipher based algorithms currently supported are

	 * AES-XCBC-MAC-96 and AES-XCBC-PRF-128.

	 */  

	const TInt KMacBlockSize = 16;		

	/** 

	 * The class is created from following substance classes

	 * 1. MMac

	 * 2. CSymmetricCipher

	 * Using the methods of the above classes we will transform/mould the Cipher methods in

	 * a way as to be inline with the MMac interface methods. The MMac methods will

	 * serve as the wrapper internal to which Cipher methods will work to provide the MAC value.

	 * 

	 * The class was created to provide consistency/similarity HMAC and CMAC works.

	 * Also for future extensibility of other Cipher algorithms.

	 */		

	NONSHARABLE_CLASS(CCMacImpl) : public CBase

		{		

	public:

		/**

		 * Cipher MAC implementation instance creation methods

		 *

		 *The owneship of 'aSymmetricCipher' is imparted to instance of this class.

		 */

		static CCMacImpl* NewL(const CKey& aKey,

			        		   CSymmetricCipher* aSymmetricCipher,	

				               TInt32 aAlgorithmUid);

		static CCMacImpl* NewLC(const CKey& aKey, 

							    CSymmetricCipher* aSymmetricCipher,	

							    TInt32 aAlgorithmUid);

		/**

		 * Simulating Methods from MPlugin

		 */

		const CExtendedCharacteristics* GetExtendedCharacteristicsL();

		// We will call CSymmetricBlockCipherImpl::Reset();

		void Reset();

		/**

		 *  Simulating MAC interfaces (Software based)

		 */

	    TPtrC8 MacL(const TDesC8& aMessage);

        void UpdateL(const TDesC8& aMessage);

        TPtrC8 FinalL(const TDesC8& aMessage);

		void ReInitialiseAndSetKeyL(const CKey& aKey);    

		void SetKeyL(const CKey& aKey);

		~CCMacImpl();

		CCMacImpl* CopyL();

		CCMacImpl* ReplicateL();

	private:

	    /**

		 * Constructors

		 */

    	CCMacImpl(CryptoSpi::CSymmetricCipher* aSymmetricCipher);

		CCMacImpl(const CCMacImpl&);

		/**

		 * Initialize the 'iCipherImpl' instances.

		 */

		void ConstructL(const CKey& aKey, TInt32 aAlgorithmUid);

		void DoUpdateL(const TDesC8& aMessage);

		TPtrC8 DoFinalL();

		void PadMessage();

		void ProcessBlockL();

		void XORKeyWithData(const TDesC8& aKey, TDes8& aOutput);

		CKey* Create128bitKeyL(const CKey& aKey);		

	private:			

		TInt32 iImplementationUid; 

		CKey* iKey;

		CryptoSpi::CSymmetricCipher* iCipherImpl;

		TBuf8<KMacBlockSize> iKey1;

		TBuf8<KMacBlockSize> iKey2;

		TBuf8<KMacBlockSize> iKey3;

		TBuf8<KMacBlockSize> iMacValue;

		TUint8 iE[KMacBlockSize];

		TUint8 iData[KMacBlockSize];

		TInt iCurrentTotalLength;

		// Resets the cipher with iE(128 zero bits) the next time MacL, 

		// UpdateL or FinalL are called. This was introduced as we cannot leave from the

		// non-leaving CCMacImpl::Reset() implementation of the MPlugin::Reset() pure 

		// virtual. To prevent behavioral break.

		TInt iDelayedReset;

		};

	}

#endif // __CRYPTOAPI_SOFTWARECIPHERMACIMPL_H__