/*

 * 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__