/*

* 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: 

* csymmetriccipher.h

* ** 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.

* CSymmetricCipher class implementation

*

*/

/**

 @file 

 @publishedPartner

 @released

*/

#ifndef __CSYMMETRICCIPHER_H__

#define __CSYMMETRICCIPHER_H__

#include <e32base.h>

/**

 * Top-level interface designed to collate the behaviour of all symmetric

 * ciphers under one interface.

 *

 * See the Cryptography api-guide documentation.

 *

 * @publishedPartner

 * @released

 */

class CSymmetricCipher : public CBase

	{

public:

	/**

	 * Runs the underlying transformation on aInput and appends the result to

	 * aOutput.

	 *

	 * For incremental buffering rules see the Cryptography api-guide documentation.

	 *

	 * @param aInput	The input data to be processed.

	 * @param aOutput	The resulting processed data appended to aOutput.  aOutput must

	 *					have MaxOutputLength() empty bytes remaining in its length.

	 */

	virtual void Process(const TDesC8& aInput, TDes8& aOutput) = 0;

	/**

	 * Pads aInput to be block aligned using the underlying padding system, if any,

	 * and then runs the underlying transformation on aInput, and appends the result

	 * to aOutput.  

	 *

	 * For incremental buffering rules see the Cryptography api-guide documentation.

	 *

	 * @param aInput	The input data to be processed.

	 * @param aOutput	The resulting, possibly padded, processed data appended to

	 *					aOutput.  aOutput must have MaxFinalOutputLength() empty bytes

	 *					remaining in its length.

	 */

	virtual void ProcessFinalL(const TDesC8& aInput, TDes8& aOutput) = 0;

	/**	

	 * Gets a tight upper bound on the number of bytes that would be returned by a

	 * call to Process() with aInputLength bytes of data.

	 *

	 * @param aInputLength	The length of data to be supplied to Process() in bytes.

	 * @return				The length of data which would result from a call to 

	 *						Process() with an aInputLength number of bytes.

	 */

	virtual TInt MaxOutputLength(TInt aInputLength) const = 0;

	/**	

	 * Gets as tight an upper bound as possible on the number of bytes that would

	 * be returned by a call to ProcessFinalL() with aInputLength bytes of data.

	 *

	 * @param aInputLength	The length of data to be supplied to Process() in bytes.

	 * @return				An upper bound on the length of data which would result from 

	 *						a call to ProcessFinalL() with an aInputLength number of bytes.

	 */

	virtual TInt MaxFinalOutputLength(TInt aInputLength) const = 0;

	/**

	 * Resets the cipher back to its original state. Clears all its buffers.

	 */

	virtual void Reset() = 0;

	/**

	 * Gets the block size in bytes (1 for stream ciphers).

	 *

	 * @return	Block size of underlying cipher in bytes.

	 */

	virtual TInt BlockSize() const = 0;

	/**

	 * Gets the key size in bits.

	 *	

	 * @return	Key size in bits.

	 */

	virtual TInt KeySize() const = 0;

};

#endif	//	__CSYMMETRICCIPHER_H__