/*

* Copyright (c) 2007-2009 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: 

* Describes Short Term Key Message (STKM) class which defines simulated short term 

* traffic encryption keys (TEKs) for the streaming reference agent.

* Protection of streamed content is accomplished by using a 4-layer key management

* architecture in OMA BCAST. In this solution, the TEKs are applied to the actual

* content and then they are encrypted by a long term encryption key (i.e. a service 

* or program encryption key). The encrypted TEKs are transported separately from the 

* streamed content. The messages carrying TEKs are called as Short Term Key messages.

* The STKM protocol is very roughly modeled here. Only IPSec is considered as 

* the traffic protection protocol of STKMs. In a real-life agent, other protection

* protocols (e.g. SRTP and ISMACryp) shall be required.

*

*/

/**

 @file

 @internalComponent

 @released

*/

#ifndef SRASTKM_H

#define SRASTKM_H

#include <e32base.h> 

#include <s32strm.h>

NONSHARABLE_CLASS(CStkm) : CBase

/**

 	Short Term Key Message description. This class contains a subset of the property 

 	fields defined in OMA BCAST. IPSec is the only protocol considered to protect STKMs

 	in this class implementation. A real-life STKM class shall have more members than this one.

 */

	{

public:

	/**

	 	Enumeration of the algorithms used to protect the traffic key material.

	 */

	enum TTkmAlgorithm

		{

		TKM_ALGO_IPSEC    = 0,	///< The protection algorithm is IPSec.

		TKM_ALGO_SRTP 	  = 1,	///< The protection algorithm is SRTP.

		TKM_ALGO_ISMACRYP = 2,	///< The protection algorithm is ISMACryp.

		TKM_ALGO_FILTER   = 0x00E0  ///< The filter which is used to get the algorithm bits of the STKM flag.

		};

public:

	IMPORT_C static CStkm* NewLC(RReadStream& aStream);

	IMPORT_C static CStkm* NewL(RReadStream& aStream);

	IMPORT_C static CStkm* NewLC(TUint16 aFlags, TUint32 aSpi, const TDesC8& aEncryptionKey, const TDesC8& aAuthenticationKey);

	IMPORT_C static CStkm* NewL(TUint16 aFlags, TUint32 aSpi, const TDesC8& aEncryptionKey, const TDesC8& aAuthenticationKey);

	IMPORT_C ~CStkm();

	IMPORT_C void ExternalizeL(RWriteStream& aStream) const;

	IMPORT_C TUint32 Spi() const;

	IMPORT_C HBufC8* EncryptionKey() const;

	IMPORT_C HBufC8* AuthenticationKey() const;

private:

	CStkm();

	void ConstructL(TUint16 aFlags, TUint32 aSpi, const TDesC8& aEncryptionKey, const TDesC8& aAuthenticationKey);

	void InternalizeL(RReadStream& aStream);

private:

	TUint16 iFlags;					///< Selectors and flags.

	TUint32 iSpi; 					///< Security parameter index.

	TUint8 iEncryptedKeyLength; 	///< Encrypted traffic key material length.

	HBufC8* iEncryptionKey; 		///< Encryption key part of the encrypted traffic key material.

	HBufC8* iAuthenticationKey; 	///< Authentication key part of the encrypted traffic key material.

	};

const TInt KMaxKeyMaterialLength     = 512;

const TInt KIpsecEncryptionKeyLength = 16;

const TInt KMinKeyMaterialLength 	 = KIpsecEncryptionKeyLength;

#endif