--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcrypto/inc/arc4.h	Wed Jul 08 11:25:26 2009 +0100
@@ -0,0 +1,125 @@
+/*
+* 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 <b>must</b> 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 <b>must</b> 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<KMaxARC4KeyBytes> iKey;
+};
+
+#endif	//	__ARC4_H__