/*

* 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: 

* srautils.h

* Defines STKM object which carries short term TEKs for DRM profile.

*

*/

#include "stkm.h"

CStkm::CStkm()

//Constructor

	{

	//empty

	}

EXPORT_C CStkm::~CStkm()

//Destructor

	{

	delete iEncryptionKey;

	delete iAuthenticationKey;

	}

EXPORT_C CStkm* CStkm::NewLC(RReadStream& aStream)

	{

	CStkm* self = new (ELeave) CStkm();

	CleanupStack::PushL(self);

	self->InternalizeL(aStream);

	return self;

	}

EXPORT_C CStkm* CStkm::NewL(RReadStream& aStream)

	{

	CStkm* self = CStkm::NewLC(aStream);

	CleanupStack::Pop(self);

	return self;

	}

EXPORT_C CStkm* CStkm::NewLC(TUint16 aFlags, TUint32 aSpi, const TDesC8& aEncryptionKey, const TDesC8& aAuthenticationKey)

	{

	CStkm* self = new (ELeave) CStkm();

	CleanupStack::PushL(self);

	self->ConstructL(aFlags, aSpi, aEncryptionKey, aAuthenticationKey);

	return self;

	}

EXPORT_C CStkm* CStkm::NewL(TUint16 aFlags, TUint32 aSpi, const TDesC8& aEncryptionKey, const TDesC8& aAuthenticationKey)

	{

	CStkm* self = CStkm::NewLC(aFlags, aSpi, aEncryptionKey, aAuthenticationKey);

	CleanupStack::Pop(self);

	return self;

	}

void CStkm::InternalizeL(RReadStream& aStream)

	{

	iFlags = aStream.ReadUint16L();

	TInt protocolValue = (iFlags & TKM_ALGO_FILTER) >> 5;

	switch(protocolValue)

		{

		case TKM_ALGO_IPSEC:

			{

			// The algorithm is IPSec. The next expected field is SPI.

			iSpi = aStream.ReadUint32L();

			iEncryptedKeyLength = aStream.ReadUint8L();

			if(iEncryptedKeyLength < KMinKeyMaterialLength || iEncryptedKeyLength > KMaxKeyMaterialLength)

				{

				// Encrypted key material is not in the expected range. The message might have been corrupted.

				User::Leave(KErrCorrupt);

				}

			// The IPSec encryption key is identical to the first 16 bytes.

			HBufC8* tmp = HBufC8::NewLC(iEncryptedKeyLength);

			TPtr8 ptr(tmp->Des());

			aStream.ReadL(ptr, iEncryptedKeyLength);

			iEncryptionKey = HBufC8::New(KIpsecEncryptionKeyLength);

			TPtr8 ptrEk(iEncryptionKey->Des());

			ptrEk.Copy(ptr.Ptr(), KIpsecEncryptionKeyLength);

			// if traffic authentication is used, the IPSec authentication key is obatined from the remaining bytes.

			if(iEncryptedKeyLength > KIpsecEncryptionKeyLength)

				{

				iAuthenticationKey = HBufC8::New(iEncryptedKeyLength - KIpsecEncryptionKeyLength);

				TPtr8 ptrAk(iAuthenticationKey->Des());

				ptrAk.Copy(ptr.Ptr() + KIpsecEncryptionKeyLength, iEncryptedKeyLength - KIpsecEncryptionKeyLength);

				}

			CleanupStack::PopAndDestroy(tmp);

			break;

			}

		case TKM_ALGO_SRTP:

		case TKM_ALGO_ISMACRYP:

			// Neither SRTP nor ISMACryp are supported by the reference agent.

			User::Leave(KErrNotSupported);

		}

	}

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

	{

	iFlags = aFlags;

	iSpi = aSpi;

	iEncryptionKey = aEncryptionKey.AllocL();

	iAuthenticationKey = aAuthenticationKey.AllocL();

	iEncryptedKeyLength = iEncryptionKey->Length() + iAuthenticationKey->Length();

	}

EXPORT_C TUint32 CStkm::Spi() const

	{

	return iSpi;

	}

EXPORT_C HBufC8* CStkm::EncryptionKey() const

	{

	return iEncryptionKey;

	}

EXPORT_C HBufC8* CStkm::AuthenticationKey() const

	{

	return iAuthenticationKey;

	}

EXPORT_C void CStkm::ExternalizeL(RWriteStream& aStream) const

	{

	aStream.WriteUint16L(iFlags);

	aStream.WriteUint32L(iSpi);

	aStream.WriteUint8L(iEncryptedKeyLength);

	aStream.WriteL(*iEncryptionKey);

	aStream.WriteL(*iAuthenticationKey);

	}