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