/*

* Copyright (c) 2005-2009 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: 

* CProtectionKey implementation

*

*/

/**

 @file 

*/

#include "authcommon_impl.h"

#include <hash.h>

using namespace AuthServer;

/**

 * Generate a new key upon construction

 * @param aKeySize the length of the key in bits.  

 **/

EXPORT_C CProtectionKey* CProtectionKey::NewL(TInt aKeySize)

	{

	CProtectionKey* key = NewLC(aKeySize);

	CleanupStack::Pop(key);

	return key;

	}

/**

 * Generate a new key upon construction

 * @param aKeySize the length of the key in bits.  

 **/

EXPORT_C CProtectionKey* CProtectionKey::NewLC(TInt aKeySize)

	{

	CProtectionKey* key = new (ELeave) CProtectionKey();

	CleanupStack::PushL(key);

	key->ConstructL(aKeySize);

	return key;

	}

/**

 * Creates a new key, passing in the key data. Should

 * really only be called by a CTransientKey::EncryptL. The new object

 * assumes ownership of the data.

 *

 * @param aKeyData the data to use as the key

 **/

EXPORT_C CProtectionKey* CProtectionKey::NewL(HBufC8* aKeyData)

	{

	CProtectionKey*  key =

	  CProtectionKey::NewLC(aKeyData);

	CleanupStack::Pop(key);

	return key;

	}

/**

 * Creates a new key, passing in the key data. Should

 * really only be called by a CTransientKey::EncryptL. The new object

 * assumes ownership of the data.

 *

 * @param aKeyData the data to use as the key

 **/

EXPORT_C CProtectionKey* CProtectionKey::NewLC(HBufC8* aKeyData)

	{

	CProtectionKey*  key = new (ELeave) CProtectionKey();

	CleanupStack::PushL(key);

	key->ConstructL(aKeyData);

	return key;

	}

/**

 * Constructor

 */

CProtectionKey::CProtectionKey()

	{

	}

/**

 * Creates a new random key of aKeySize

 * @param aKeySize the size of the key to generate

 **/

void CProtectionKey::ConstructL(TInt aKeySize)

	{

	iKeyData = HBufC8::NewMaxL(aKeySize);

	TPtr8 data = iKeyData->Des();

	TRandom::RandomL(data);

	}

/**

 * Deletes the keydata.

 **/

CProtectionKey::~CProtectionKey()

	{

	delete iKeyData;

	}

/**

 * Creates a new protection key generated using a combination of this key

 * and the client UID. Ownership of the returned object is passed to the 

 * caller.

 *

 * @param aClientUid the client uid to use in the generation process.

 *

 * @return a new heap allocated protection key 

 **/

EXPORT_C CProtectionKey* CProtectionKey::ClientKeyL(TInt aClientUid) const

	{

	CSHA1* sha1 = CSHA1::NewL();

	CleanupStack::PushL(sha1);

	TPckg<TIdentityId> idPckg(aClientUid);

	sha1->Update(idPckg);

	sha1->Update(*iKeyData);

	TInt keyLength = iKeyData->Length();

	HBufC8* newKey = HBufC8::NewLC(keyLength);

	TInt remaining = keyLength;

	do

	  {

		newKey->Des().Append(sha1->Hash(idPckg).Left(remaining));

		remaining = keyLength - newKey->Length(); 

	  } while ( remaining > 0);

	CProtectionKey* key = NewL(newKey);

	CleanupStack::Pop(newKey);

	CleanupStack::PopAndDestroy(sha1);

	return key;

	}

/**

 * Returns a descriptor to the key data for use in encryption and 

 * decryption methods. 

 *

 * @return a descripter pointing to the key data. 

 **/

EXPORT_C TPtrC8 CProtectionKey::KeyData() const

    {

	return *iKeyData;

    }

/**

 * Constructs the key using supplied data.

 **/

void CProtectionKey::ConstructL(HBufC8* aKeyData)

	{

	__ASSERT_DEBUG(((iKeyData == 0) &&

				   (aKeyData != 0)),

					User::Leave(KErrArgument));

	iKeyData = aKeyData;

    }