/*

 * Copyright (c) 2006-2010 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: 

 *

 */

 #ifndef	__3DESIMPL_H__

 #define	__3DESIMPL_H__

 /**

 @file 

 @internalComponent

 @released

 */

 #include <e32base.h>

 #include <e32cmn.h>

 #include <cryptospi/keys.h>

 #include "desimpl.h"

 /**

 Plug-in class for 3DES block cipher

 */

 namespace SoftwareCrypto

 	{

 	NONSHARABLE_CLASS(C3DesImpl) : public CDesImpl

 		{

 	public:

 		/**

 		Creates an instance of a 3DES (Data Encryption Standard) symmetric cipher plug-in.

 		@param aKey The key

 		@param aCryptoMode Whether to encrypt or decrypt

 		@param aOperationMode The block cipher mode ECB, CBC, CTR etc

 		@param aPadding The padding scheme to use None, SSLv3, PKCS#7

 		@return A pointer to a C3DesImpl instance

 		*/

 		static C3DesImpl* NewL(const CryptoSpi::CKey& aKey, 

 			TUid aCryptoMode, TUid aOperationMode, TUid aPadding);

 		/**

 		Creates an instance of a 3DES (Data Encryption Standard) symmetric cipher plug-in.

 		A pointer to the plug-in instance is placed on the cleanup stack.

 		@param aKey The key

 		@param aCryptoMode Whether to encrypt or decrypt

 		@param aOperationMode The block cipher mode ECB, CBC, CTR etc

 		@param aPadding The padding scheme to use None, SSLv3, PKCS#7

 		@return A pointer to a C3DesImpl instance

 		*/

 		static C3DesImpl* NewLC(const CryptoSpi::CKey& aKey, 

 			TUid aCryptoMode, TUid aOperationMode, TUid aPadding);

 		// From CSymmetricCipherImpl

 		TBool IsValidKeyLength(TInt aKeyBytes) const;

 		TInt GetKeyStrength() const;

 		TUid ImplementationUid() const;

 		/// 3Destructor

 		~C3DesImpl();

 	private:

 		/**

 		Constructor

 		@param aOperationMode The mode of operation e.g. CBC

 		@param aCryptoMode Whether to encrypt or decrypt

 		@param aPaddingMode The padding mode to use. None, SSL, PKCS#7

 		*/

 		C3DesImpl(TUid aOperationMode, TUid aCryptoMode, TUid aPaddingMode);

 		///	second phase of construction	

 		void ConstructL(const CryptoSpi::CKey& aKey);						

 		/**

 		Creates the key schedules iK1, iK2, iK3 from CBlockTransformationImpl::iKey.

 		This should be called from ConstructL and Reset

 		*/

 		void SetKeySchedule();

 		// From CSymmetricBlockCipherImpl

 		void TransformEncrypt(TUint8* aBuffer, TUint aNumBlocks);

 		void TransformDecrypt(TUint8* aBuffer, TUint aNumBlocks);

 	private:

 		/// Size of the key schedule in words

 		static const TUint KKeyScheduleSize = 32;

 		/// the key schedules

 		TUint32 iK1[KKeyScheduleSize];

 		TUint32 iK2[KKeyScheduleSize];

 		TUint32 iK3[KKeyScheduleSize];

 		static const TUint8 K3DesBlockBytes = 8;

 		static const TUint8 K3DesKeyBytes = 24;

 		};

 	}

 #endif // __3DESIMPL_H__