/*

* 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.

* 3DES implementation

*

*/

/**

 @file 

 @publishedPartner

 @released 

*/

#ifndef __3DES_H__

#define __3DES_H__

#include <des.h>

/**

* Abstract base class for triple-DES.

*

* Implements features common to triple-DES encryption and decryption.

*

*/

class C3DES : public CDES

{

public:

	virtual void Transform(TDes8& aBlock);

	virtual void Reset();

	virtual TInt BlockSize() const;

	virtual TInt KeySize() const;

protected:

	/** @internalAll */

	C3DES();

	virtual void ConstructL(const TDesC8& aKey);

	/**

	 * Initialises the three key schedule arrays from the specified key.

	 * 

	 * @param aKey	The key to be used for encryption. The key length

	 *				must be K3DESKeySize = 24 bytes.

	 */

	virtual void DoSetKey(const TDesC8& aKey) = 0;

protected:

	/** The second key schedule array */

	TUint32 iK2[KDESScheduleSizeInWords];	//	= 32

	/** The third key schedule array */

	TUint32 iK3[KDESScheduleSizeInWords];

};

/**

* Concrete class for triple-DES encryption.

*

*/

class C3DESEncryptor : public C3DES

{

public:

	/**

	* Creates an instance of this class.

	*

	* @param aKey	The key to be used for encryption. The key length

	*				must be K3DESKeySize = 24 bytes.

	* @return		A pointer to the new C3DESEncryptor object.

	*

	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the

	*								cipher strength restrictions of the crypto library.

	*								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	IMPORT_C static C3DESEncryptor* NewL(const TDesC8& aKey);

	/**

	* Creates an instance of this class and leaves it on the cleanup stack.

	*

	* @param aKey	The key to be used for encryption. The key length

	*				must be K3DESKeySize = 24 bytes.

	* @return		A pointer to the new C3DESEncryptor object.

	*

	* @leave KErrKeyNotWeakEnough 	If the key size is larger than that allowed by the

	* 								cipher strength restrictions of the crypto library.

	* 								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	IMPORT_C static C3DESEncryptor* NewLC(const TDesC8& aKey);

protected:

	virtual void DoSetKey(const TDesC8& aKey);

};

/**

* Concrete class for triple-DES decryption.

*

*/

class C3DESDecryptor : public C3DES

{

public:

	/**

	* Creates an instance of this class.

	*

	* @param aKey	The key to be used for decryption. The key length

	*				must be K3DESKeySize = 24 bytes.

	* @return		A pointer to the new C3DESDecryptor object.

	*

	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the

	*								cipher strength restrictions of the crypto library.

	*								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	IMPORT_C static C3DESDecryptor* NewL(const TDesC8& aKey);

	/**

	* Creates an instance of this class and leaves it on the cleanup stack.

	*

	* @param aKey	The key to be used for decryption. The key length

	*				must be K3DESKeySize = 24 bytes.

	* @return		A pointer to the new C3DESDecryptor object.

	*

	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the

	*								cipher strength restrictions of the crypto library.  

	*								See TCrypto::IsSymmetricWeakEnoughL()

	*/

	IMPORT_C static C3DESDecryptor* NewLC(const TDesC8& aKey);

protected:

	virtual void DoSetKey(const TDesC8& aKey);

};

#endif	//	__3DES_H__