/*

* Copyright (c) 2002-2009 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: 

* ** IMPORTANT ** PublishedPartner API's in this file are published to 3rd party developers via the 

* Symbian website. Changes to these API's should be treated as PublishedAll API changes and the Security TA should be consulted.

* CBC mode encryptor and decryptor implementation

*

*/

/**

 @file 

 @publishedPartner

 @released 

*/

#ifndef __CBCMODE_H__

#define __CBCMODE_H__

#include "mode.h"

/**

* Concrete subclass of CBlockChainingMode implementing CBC mode block chaining

* for encryption.

*

*/

class CModeCBCEncryptor : public CBlockChainingMode

{

public:

	/**

	* Creates an object of this class for CBC mode encryption.

	*

	* @param aBT	An appropriate CBlockTransformation derived encryptor.

	* @param aIV	Initialization vector, the length of this descriptor must be

	*				the same as the underlying cipher's block size.

	* @return		A pointer to the new CModeCBCEncryptor object

	*/

	IMPORT_C static CModeCBCEncryptor* NewL(CBlockTransformation* aBT, 

		const TDesC8& aIV);

	/**

	* Creates an object of this class for CBC mode encryption.

	*

	* The returned pointer is put onto the cleanup stack.

	*

	* @param aBT	An appropriate CBlockTransformation derived encryptor.

	* @param aIV	Initialization vector, the length of this descriptor must be

	*				the same as the underlying cipher's block size.

	* @return		A pointer to the new CModeCBCEncryptor object

	*/

	IMPORT_C static CModeCBCEncryptor* NewLC(CBlockTransformation* aBT, 

		const TDesC8& aIV);

	virtual void Transform(TDes8& aBlock);	

protected:

	/**

	 * @internalAll

	 */

	CModeCBCEncryptor();

private:

	const CModeCBCEncryptor& operator=(const CModeCBCEncryptor&);

};

/**

* Concrete subclass of CBlockChainingMode implementing CBC mode block chaining

* for decryption.

*

*/

class CModeCBCDecryptor : public CBlockChainingMode

{

public:

	/**

	* Creates an object of this class for CBC mode decryption.

	* 

	* @param aBT	An appropriate CBlockTransformation derived decryptor.

	* @param aIV	Initialization vector, the length of this descriptor must be

	*				the same as the underlying cipher's block size.

	* @return		A pointer to the CModeCBCDecryptor new object.

	*/

	IMPORT_C static CModeCBCDecryptor* NewL(CBlockTransformation* aBT, 

		const TDesC8& aIV);

	/**

	* Creates an object of this class for CBC mode decryption.

	*

	* The returned pointer is put onto the cleanup stack.

	* 

	* @param aBT	An appropriate CBlockTransformation derived decryptor.

	* @param aIV	Initialization vector, the length of this descriptor must be

	*				the same as the underlying cipher's block size.

	* @return		A pointer to the CModeCBCDecryptor new object.

	*/

	IMPORT_C static CModeCBCDecryptor* NewLC(CBlockTransformation* aBT, 

		const TDesC8& aIV);

	virtual ~CModeCBCDecryptor(void);

public:

	virtual void Transform(TDes8& aBlock);	

protected:

	/** @internalAll */

	CModeCBCDecryptor();

	/** @internalAll */

	void ConstructL(CBlockTransformation* aBT, const TDesC8& aIV);

private:

	HBufC8* iIVBakBuf;

	TPtr8 iIVBak;

private:

	const CModeCBCDecryptor& operator=(const CModeCBCDecryptor&);

};

#endif	//	__CBCMODE_H__