// Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "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:

// Authentication Protocol (CHAP) - RFC 1994, containing source code

// common to all PPP authentication protocols derived from CHAP.

// 

//

/**

 @file

 @brief Header file for the implementation of PPP Challenge Handshake

 @internalComponent 

*/

#ifndef __PPPCHAP_H__

#define __PPPCHAP_H__

// use RMBufChain, RMBufPacket

#include <nifmbuf.h>

#include "PPPAUTH.H"

// protocol specific constants for CHAP

/**

   The value of the CHAP Challenge Code.

   @internalComponent

*/

const TUint8 KPppChapChallengeCode = 1u;

/**

   The value of the CHAP Response Code.

   @internalComponent

*/

const TUint8 KPppChapResponseCode = 2u;

/**

   The value of the CHAP Success Code.

   @internalComponent

*/

const TUint8 KPppChapSuccessCode = 3u;

/**

   The value of the CHAP Failure Code.

   @internalComponent

*/

const TUint8 KPppChapFailureCode = 4u;

/**

   The size of the CHAP Code field.

   @internalComponent

*/

const TUint8 KPppChapCodeFieldSize = 1u;

/**

   The size of the CHAP Identifier field.

   @internalComponent

*/

const TUint8 KPppChapIdFieldSize = 1u;

/**

   The size of the CHAP Length field.

   @internalComponent

*/

const TUint8 KPppChapLengthFieldSize = 2u;

/**

   The size of the CHAP Value-Size field.

   @internalComponent

*/

const TUint8 KPppChapValueSizeFieldSize = 1u;

/**

   The minimum size of the CHAP Value field of Challenge & Response

   packets.

   @internalComponent

*/

const TUint8 KPppChapMinValueSize = 1u;

/**

   The minimum size of the CHAP Name field of Challenge & Response

   packets.

   @note While RFC 1994 states that: "The Name field is one or more

   octets [...]", in the case of MS-CHAP-V1 and MS-CHAP-V2 the Name

   field of the Challenge packet may be empty.  RFC2433 and RFC2759

   state that: "Microsoft authenticators do not currently provide

   information in the Name field.  This may change in the future."

   @internalComponent

*/

const TUint8 KPppChapMinNameSize = 1u;

/**

   Default period of the timer used for CHAP response retries.

   @internalComponent

*/

const TInt KPppChapResponseRetryTimerPeriod = 3000;

/**

   Default number of CHAP response retries.

   @internalComponent

*/

const TInt KPppChapMaxResponseRetryCount = 4;

NONSHARABLE_CLASS(CPppChap) : public CPppAuthentication, protected MTimer

/**

   Abstract base class for classes that implement the PPP Challenge

   Handshake Authentication Protocol (CHAP) or other PPP

   authentication protocols derived from CHAP - RFC 1994.

   @internalComponent

*/

	{

  public:

	virtual ~CPppChap();

	virtual void InitL(CPppLcp* aLcp);

	virtual void AuthenticateComplete(TInt aStatus);

	virtual TBool RecvFrame(RMBufChain& aPacket);

	virtual void LowerLayerUp();

	virtual void LowerLayerDown(TInt aStatus=KErrNone);

  protected:

	virtual void TimerComplete(TInt aStatus);

	/*final*/ virtual TUint PppId() const;

	virtual void ChallengeL(RMBufPacket& aPacket);

	virtual void SuccessL(RMBufPacket& aPacket);

	virtual void FailureL(RMBufPacket& aPacket);

	virtual void CheckChallengePacketL(RMBufPacket& aPacket);

/**

   Computes the CHAP Response Value and the CHAP Response Name.

   @param aChallengeId [in] The CHAP Challenge Identifier.

   @param aChallengeValue [in] The CHAP Challenge Value.

   @param aResponseValue [out] The CHAP Response Value.

   @param aResponseName [out] The CHAP Response Name.

*/

	virtual void MakeResponseL(TUint8 aChallengeId,

							   const TDesC8& aChallengeValue,

							   TPtrC8& aResponseValue,

							   TPtrC8& aResponseName)=0;

	void ProcessChallengePacketL(RMBufPacket& aPacket);

	void RespondL();

	void RetryResponseL();

	void SendResponseL(TUint8 aResponseId, 

					   const TDesC8& aResponseValue, 

					   const TDesC8& aResponseName);

	TBool CheckIdentifier(RMBufPacket& aPacket) const;

	static void MakeResponsePacketLC(TUint8 aIdentifier, 

									 const TDesC8& aValue, 

									 const TDesC8& aName, 

									 RMBufPacket& aPacket);

  protected:

	CPppChap();

/** Pointer to the latest CHAP Challenge received. */

	TPtr8 iChallengeRef;

/** The response retry count. */

	TInt iResponseRetryCount;

/** The latest CHAP Challenge Identifier received. */

	TUint8	iCurrentId;

  private:

/** Pointer to the CHAP Response Value. */

	TPtrC8 iResponseValueRef;

/** Pointer to the CHAP Response Name. */

	TPtrC8 iResponseNameRef;

/** The latest CHAP Challenge packet received. */

	RMBufChain iChallengePacket;

	};

inline TBool CPppChap::CheckIdentifier(RMBufPacket& aPacket) const

/**

   Verifies that the identifier contained in the packet matches the

   latest Challenge Identifier received.

   @param aPacket [in] A CHAP Success or Failure packet.

*/

	{

	return *(aPacket.First()->Ptr() + KPppChapCodeFieldSize) ==

				iCurrentId;

	}

inline TUint CPppChap::PppId() const

/**

   @copydoc CPppAuthentication::PppId()

   @see CPppAuthentication::PppId()

*/

	{

	return KPppIdChap;

	}

inline CPppChap::CPppChap()

	: iChallengeRef(NULL, 0)

	{

	}

#endif // ___PPPCHAP_H__