/*

* Copyright (c) 2006-2009 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	__RC2_H__

#define	__RC2_H__

/**

@file 

@internalComponent

@released

*/

#include <e32base.h>

#include <e32cmn.h>

#include "keys.h"

#include "symmetriccipherimpl.h"

/**

Plug-in class for RC2 block cipher

*/

namespace SoftwareCrypto

	{

	using namespace CryptoSpi;

	NONSHARABLE_CLASS(CRc2Impl) : public CSymmetricBlockCipherImpl

		{

	public:

		/**

		Creates an instance of an RC2 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

		@param aEffectiveKeyLenBits The effective key length in bits

		@return A pointer to a CRc2Impl instance

		*/

		static CRc2Impl* NewL(const CKey& aKey, 

			TUid aCryptoMode, TUid aOperationMode, TUid aPadding, TInt aEffectiveKeyLenBits);

		/**

		Creates an instance of an RC2 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

		@param aEffectiveKeyLenBits The effective key length in bits

		@return A pointer to a CRc2Impl instance

		*/

		static CRc2Impl* NewLC(const CKey& aKey, 

			TUid aCryptoMode, TUid aOperationMode, TUid aPadding, TInt aEffectiveKeyLenBits);

		// From CSymmetricCipherImpl

		TBool IsValidKeyLength(TInt aKeyBytes) const;

		TUid ImplementationUid() const;

		TInt GetKeyStrength() const;

		const CExtendedCharacteristics* GetExtendedCharacteristicsL();

		static CExtendedCharacteristics* CreateExtendedCharacteristicsL();

		/// Destructor

		~CRc2Impl();

		/** SSL Effective Key Length Compatibility - for compatibility with SSL */

		static const TUint KDefaultEffectiveKeyLenBits = 1024;

	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

		*/

		CRc2Impl(TUid aOperationMode, TUid aCryptoMode, TUid aPaddingMode);

		///	second phase of construction	

		void ConstructL(const CKey& aKey, TInt aEffectiveKeyLenBits);

		/**

		Expands the key (iKey) to iEffectiveKeyLenBits and stores the result in iK

		*/

		void SetKeySchedule();

		// From CSymmetricBlockCipherImpl

		void TransformEncrypt(TUint8* aBuffer, TUint aNumBlocks);

		void TransformDecrypt(TUint8* aBuffer, TUint aNumBlocks);		

	private:		

		static const TUint8 KRc2BlockBytes = 8;

		static const TInt KRc2MaxKeySizeBytes = 128;	

		static const TInt KRc2ExpandedKeyLen = 64;

		/**

	 	 The expanded key buffer.

		 Each iK[i] is a 16-bit word.

	 	 */

		TUint16 iK[KRc2ExpandedKeyLen];	//	128 bytes		

		/** The effective key length in bits */

		TInt iEffectiveKeyLenBits;	

		};

	}

#endif //__RC2_H__