diff -r 675a964f4eb5 -r 35751d3474b7 crypto/weakcrypto/inc/arc4.h --- a/crypto/weakcrypto/inc/arc4.h Tue Jul 21 01:04:32 2009 +0100 +++ b/crypto/weakcrypto/inc/arc4.h Thu Sep 10 14:01:51 2009 +0300 @@ -1,125 +1,122 @@ -/* -* 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. -* RC4 implementation -* -*/ - - - - -/** - @file - @internalAll -*/ - -#ifndef __ARC4_H__ -#define __ARC4_H__ - -#include "streamcipher.h" - -/** The size of the substitution box (i.e. lookup table) in bytes. */ -const TInt KSBoxSize = 256; - -/** Maximum ARC4 key size in bytes. */ -const TInt KMaxARC4KeyBytes = 256; //2048 bits - -/** Number of bytes to discard by default from an ARC4 key stream. */ -const TUint KDefaultDiscardBytes = 768; - -/** -* Implements an RC4-compatible stream cipher that outputs a pseudorandom stream -* of bits, having been initialised with a key. -* -* @publishedPartner -* @released -*/ -class CARC4 : public CStreamCipher -{ -public: - /** - * Constructs an instance of a CARC4 object, and initialises it with a key and - * (optionally) the number of initial bytes to discard. Defaults to 256. - * - * The number of dropped bytes must be agreed with the other - * party, with which information is to be exchanged, prior to encipherment. - * - * @note Several papers have been published indicating that there are weaknesses - * in the first bytes of an ARC4 byte stream. A search for "ARC4 - * discard" should find these papers. Recommended practice is to drop the first - * KDefaultDiscardBytes bytes of the key stream. - * - * @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 the new CARC4 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 CARC4* NewL(const TDesC8& aKey, - TUint aDiscardBytes = KDefaultDiscardBytes); - - /** - * Constructs an instance of a CARC4 object, and initialises it with a key and - * (optionally) the number of initial bytes to discard. Defaults to 256. - * - * The number of dropped bytes must be agreed with the other - * party, with which information is to be exchanged, prior to encipherment. - * - * @see CARC4::NewL() - * - * @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 the new CARC4 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 CARC4* NewLC(const TDesC8& aKey, - TUint aDiscardBytes = KDefaultDiscardBytes); -public: - virtual void Reset(void); - virtual TInt KeySize(void) const; -protected: - /** - * Performs an ARC4 encryption or decryption on supplied data. - * - * @note ARC4 encryption and decryption are symmetrical. - * - * @param aData On input, data to be transformed; - * on return, transformed data. - */ - virtual void DoProcess(TDes8& aData); -private: - CARC4(const TDesC8& aKey, TUint aDiscardBytes); - void GenerateSBox(); - inline TUint8 GenerateByte(); - void DiscardBytes(TInt aDiscardBytes); -private: - TUint8 ix; - TUint8 iy; - TInt iDiscardBytes; - TUint8 iState[KSBoxSize]; - TBuf8 iKey; -}; - -#endif // __ARC4_H__ +/* +* 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. +* RC4 implementation +* +*/ + + +/** + @file + @publishedPartner + @released +*/ + +#ifndef __ARC4_H__ +#define __ARC4_H__ + +#include "streamcipher.h" + +/** The size of the substitution box (i.e. lookup table) in bytes. */ +const TInt KSBoxSize = 256; + +/** Maximum ARC4 key size in bytes. */ +const TInt KMaxARC4KeyBytes = 256; //2048 bits + +/** Number of bytes to discard by default from an ARC4 key stream. */ +const TUint KDefaultDiscardBytes = 768; + +/** +* Implements an RC4-compatible stream cipher that outputs a pseudorandom stream +* of bits, having been initialised with a key. +* +*/ +class CARC4 : public CStreamCipher +{ +public: + /** + * Constructs an instance of a CARC4 object, and initialises it with a key and + * (optionally) the number of initial bytes to discard. Defaults to 256. + * + * The number of dropped bytes must be agreed with the other + * party, with which information is to be exchanged, prior to encipherment. + * + * @note Several papers have been published indicating that there are weaknesses + * in the first bytes of an ARC4 byte stream. A search for "ARC4 + * discard" should find these papers. Recommended practice is to drop the first + * KDefaultDiscardBytes bytes of the key stream. + * + * @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 the new CARC4 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 CARC4* NewL(const TDesC8& aKey, + TUint aDiscardBytes = KDefaultDiscardBytes); + + /** + * Constructs an instance of a CARC4 object, and initialises it with a key and + * (optionally) the number of initial bytes to discard. Defaults to 256. + * + * The number of dropped bytes must be agreed with the other + * party, with which information is to be exchanged, prior to encipherment. + * + * @see CARC4::NewL() + * + * @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 the new CARC4 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 CARC4* NewLC(const TDesC8& aKey, + TUint aDiscardBytes = KDefaultDiscardBytes); +public: + virtual void Reset(void); + virtual TInt KeySize(void) const; +protected: + /** + * Performs an ARC4 encryption or decryption on supplied data. + * + * @note ARC4 encryption and decryption are symmetrical. + * + * @param aData On input, data to be transformed; + * on return, transformed data. + */ + virtual void DoProcess(TDes8& aData); +private: + CARC4(const TDesC8& aKey, TUint aDiscardBytes); + void GenerateSBox(); + inline TUint8 GenerateByte(); + void DiscardBytes(TInt aDiscardBytes); +private: + TUint8 ix; + TUint8 iy; + TInt iDiscardBytes; + TUint8 iState[KSBoxSize]; + TBuf8 iKey; +}; + +#endif // __ARC4_H__