/*

* 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: 

* ARC4 shim classes definition

*

*/

/**

 @file

 @internalComponent

 @released

*/

#ifndef ARC4SHIM_H

#define ARC4SHIM_H

#include <arc4.h>

namespace CryptoSpi

	{

	class CCryptoParams;

	class CSymmetricCipher;

	class CKey;

	}

NONSHARABLE_CLASS(CArc4Shim) : public CARC4

{

public:

	/**

	Creates a CArc4Shim object which has the same interface as CARC4 

	but delegates all work to a Crypto SPI plug-in.

	@param aKey					The key to use. aKey must be less 

								than or equal to KRC4MaxKeySizeBytes.  

	@param aDiscardBytes		The number of bytes to drop from the 

								beginning of the key stream.

	@return						A pointer to a CArc4Shim instance

	@leave KErrKeyNotWeakEnough	If the key size is larger than that 

								allowed by the cipher strength 

								restrictions of the crypto library.

								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	static CArc4Shim* NewL(const TDesC8& aKey, TUint aDiscardBytes);

	/**

	Creates a CArc4Shim object which has the same interface as CARC4,

	and leave it on the cleanup stack. but delegates all work to a 

	Crypto SPI plug-in.

	@param aKey					The key to use. aKey must be less 

								than or equal to KRC4MaxKeySizeBytes.  

	@param aDiscardBytes		The number of bytes to drop from the 

								beginning of the key stream.

	@return						A pointer to a CArc4Shim instance

	@leave KErrKeyNotWeakEnough	If the key size is larger than that 

								allowed by the cipher strength 

								restrictions of the crypto library.

								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	static CArc4Shim* NewLC(const TDesC8& aKey, TUint aDiscardBytes);

	/**

	Destructor

	*/

	~CArc4Shim();

	// From CSymmetricCipher class

	void Reset();

	TInt BlockSize() const;

	TInt KeySize() const;		

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

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

	TInt MaxOutputLength(TInt aInputLength) const;

	TInt MaxFinalOutputLength(TInt aInputLength) const;

private:

	/** 

	Constructor

	*/

	CArc4Shim();

	/**

	Second Phase Constructor

	*/

	void ConstructL(const TDesC8& aKey, TUint aDiscardBytes);

private:

	/// SPI delegate

	CryptoSpi::CSymmetricCipher* iSymmetricCipherImpl;

	/// SPI requires all key to passed as key-objects

	CryptoSpi::CKey* iKey;

	CryptoSpi::CCryptoParams* iAlgorithmParams;

};

#endif // ARC4SHIM_H