/*+
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* Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).+
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* All rights reserved.+
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* This component and the accompanying materials are made available+
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* under the terms of the License "Eclipse Public License v1.0"+
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* which accompanies this distribution, and is available+
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* at the URL "http://www.eclipse.org/legal/epl-v10.html".+
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*+
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* Initial Contributors:+
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* Nokia Corporation - initial contribution.+
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*+
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* Contributors:+
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*+
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* Description: +
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* ** IMPORTANT ** PublishedPartner API's in this file are published to 3rd party developers via the +
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* Symbian website. Changes to these API's should be treated as PublishedAll API changes and the Security TA should be consulted.+
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* DES encryptor and decryptor implementation+
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*+
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*/+
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+
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+
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+
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/**+
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 @file +
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 @internalAll+
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*/+
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 +
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#ifndef __DATAENCRYPTIONSTANDARD_H__+
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#define __DATAENCRYPTIONSTANDARD_H__+
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+
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#include "blocktransformation.h"+
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#include <securityerr.h>+
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+
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/** The size of the key schedule array (in 32-bit words).+
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* +
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* @publishedPartner+
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* @released +
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*/+
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const TUint KDESScheduleSizeInWords = 32;+
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+
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/**+
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* Abstract base class for DES, implementing features common between DES encryption and+
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* decryption. From CBlockTransformation+
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* +
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* @publishedPartner+
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* @released +
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*/+
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class CDES : public CBlockTransformation+
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{+
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public:	+
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	virtual void Transform(TDes8& aBlock);+
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	virtual TInt BlockSize() const;+
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	virtual TInt KeySize() const;+
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	virtual void Reset();+
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	/**+
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	 * Indicates whether a supplied key is weak. If the key is one of the weak keys+
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	 * defined by the crypto library (e.g. {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01})+
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	 * ETrue is returned.+
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	 * +
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	 * @param aKey	    		The Key to be checked. The key length must be+
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	 							KDESKeySize = 8 bytes.+
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	 * @return					Whether the key is weak (ETrue or EFalse)+
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	 *						+
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	 */+
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	IMPORT_C static TBool IsWeakKey(const TDesC8& aKey);+
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	virtual ~CDES();+
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protected:+
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	/** @internalAll */+
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	CDES();+
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	/** @internalAll */+
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	void DoTransform(TUint32& l, TUint32& r, const TUint32* aKey);+
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	virtual void SetKey(const TDesC8& aKey, TUint32* aKeyBuffer);+
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	virtual void ConstructL(const TDesC8& aKey, TBool aCheckWeakKey);+
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protected:+
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	/** +
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	 * Key schedule array +
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	 *+
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	 * Also used as the first key in triple-DES+
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	 */+
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	TUint32 iK1[KDESScheduleSizeInWords];	//	= 32+
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	/** +
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	 * The initial key. +
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	 *+
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	 * The key length must be KDESKeySize = 8 bytes.+
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	 */+
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	HBufC8* iKey;+
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};+
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+
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/**+
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* Concrete class for DES encryption.+
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* +
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* @publishedPartner+
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* @released +
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*/+
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class CDESEncryptor : public CDES+
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{+
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public:+
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	/**+
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	* Creates an instance of this class.+
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	* +
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	* @param aKey			The key to be used for encryption. The key length must be+
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	*						KDESKeySize = 8 bytes.+
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	* @param aCheckWeakKey	Boolean determining whether to check the key against+
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	*						a set of known weak key values. Defaults to ETrue. +
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	* @return				A pointer to the new CDESEncryptor object.+
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	*+
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	* @leave KErrWeakKey			If the key is a weak one, the function leaves having+
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	*								previously cleaned up any previously allocated memory.+
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	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the+
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	*								cipher strength restrictions of the crypto library.+
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	* 								See TCrypto::IsSymmetricWeakEnoughL()+
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	*/+
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	IMPORT_C static CDESEncryptor* NewL(const TDesC8& aKey, TBool aCheckWeakKey = ETrue);+
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+
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	/**+
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	* Creates an instance of this class and leaves it on the cleanup stack.+
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	*+
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	* @param aKey			The key to be used for encryption. The key length must be+
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	*						KDESKeySize = 8 bytes.+
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	* @param aCheckWeakKey	Boolean determining whether to check the resultant key against+
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	*						a set of known weak key values. Defaults to ETrue. +
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	* @return				A pointer to the new CDESEncryptor object.+
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	*+
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	* @leave KErrWeakKey			If the key is a weak one, the function leaves having+
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	*								previously cleaned up any previously allocated memory.+
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	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the+
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	*								cipher strength restrictions of the crypto library.+
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	*								See TCrypto::IsSymmetricWeakEnoughL()+
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	*/+
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	IMPORT_C static CDESEncryptor* NewLC(const TDesC8& aKey, TBool aCheckWeakKey = ETrue);+
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private:+
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	CDESEncryptor(void);+
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};+
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+
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/**+
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* Concrete class for DES decryption.+
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*+
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* @publishedPartner+
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* @released +
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*/+
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class CDESDecryptor : public CDES+
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{+
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public:+
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	/**+
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	* Creates an instance of this class.+
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	*+
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	* @param aKey			The key to be used for decryption. The key length must be+
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	*						KDESKeySize = 8 bytes.+
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	* @param aCheckWeakKey	Boolean determining whether to check the resultant key against+
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	*						a set of known weak key values. Defaults to ETrue.+
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	* @return				A pointer to the new CDESDecryptor object.+
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	*+
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	* @leave KErrWeakKey			If the key is a weak one, the function leaves having+
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	*								previously cleaned up any previously allocated memory.+
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	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the+
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	*								cipher strength restrictions of the crypto library.+
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	*								See TCrypto::IsSymmetricWeakEnoughL()+
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	*/+
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	IMPORT_C static CDESDecryptor* NewL(const TDesC8& aKey, TBool aCheckWeakKey = ETrue);+
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+
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	/**+
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	* Creates an instance of this class and leaves it on the cleanup stack.+
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	* +
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	* @param aKey			The key to be used for decryption. The key length must be+
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	*						KDESKeySize = 8 bytes.+
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	* @param aCheckWeakKey	Boolean determining whether to check the resultant key against+
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	*						a set of known weak key values. Defaults to ETrue.+
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	* @return				A pointer to the new CDESDecryptor object.+
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	*+
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	* @leave KErrWeakKey			If the key is a weak one, the function leaves having+
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	*								previously cleaned up any previously allocated memory.+
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	* @leave KErrKeyNotWeakEnough	If the key size is larger than that allowed by the+
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	*								cipher strength restrictions of the crypto library.+
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	*								See TCrypto::IsSymmetricWeakEnoughL()+
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	*/+
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	IMPORT_C static CDESDecryptor* NewLC(const TDesC8& aKey, TBool aCheckWeakKey = ETrue);+
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protected:	//	From CDES+
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	virtual void SetKey(const TDesC8& aKey, TUint32* aKeyBuffer);+
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private:+
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	CDESDecryptor(void);+
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};+
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+
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#endif	//	__DATAENCRYPTIONSTANDARD_H__+
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