/*

 * 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: 

 *

 */

 #include <cbcmode.h>

 #include "cbcmodeshim.h"

 #include "../common/inlines.h"

 void CBlockChainingMode::Reset()

 	{

 	iRegister.Copy(iIV);

 	iBT->Reset();

 	}

 TInt CBlockChainingMode::BlockSize() const

 	{

 	return (iBT->BlockSize());

 	}

 TInt CBlockChainingMode::KeySize() const

 	{

 	return (iBT->KeySize());

 	}

 void CBlockChainingMode::SetIV(const TDesC8& aIV)

 	{

 	//We are making the stipulation that anybody calling SetIV is not setting it

 	//to a longer IV than they originally did.  Otherwise SetIV needs to leave.

 	assert(aIV.Size() <= iIV.Size());

 	iIV.Copy(aIV);

 	Reset();

 	}

 EXPORT_C CBlockChainingMode::CBlockChainingMode() 

 	: iBT(NULL), iRegister(0,0,0), iIV(0,0,0)

 	{

 	}

 EXPORT_C CBlockChainingMode::~CBlockChainingMode()

 	{

 	delete iBT;

 	delete iRegisterBuf;

 	delete iIVBuf;

 	}

 EXPORT_C void CBlockChainingMode::ConstructL(CBlockTransformation* aBT, const TDesC8& aIV)

 	{

 	iRegisterBuf = aIV.AllocL();

 	iRegister.Set(iRegisterBuf->Des());

 	iIVBuf = aIV.AllocL();

 	iIV.Set(iIVBuf->Des());

 	// Take ownership last - doesn't take ownership if we leave

 	iBT = aBT;

 	}

 /* CModeCBCEncryptor */

 EXPORT_C CModeCBCEncryptor* CModeCBCEncryptor::NewL(CBlockTransformation* aBT, 

 	const TDesC8& aIV)

 	{	

 	CModeCBCEncryptor* self = CModeCBCEncryptorShim::NewL(aBT, aIV);

 	if (! self)

 		{			

 		// not able to use CryptoSpi, possibly due to an exterally 

 		// derived legacy class so fallback to old implementation.			

 		self = NewLC(aBT,aIV);

 		CleanupStack::Pop(self);

 		}	

 	return self;	

 	}

 EXPORT_C CModeCBCEncryptor* CModeCBCEncryptor::NewLC(CBlockTransformation* aBT,

 	const TDesC8& aIV)

 	{

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

 	CleanupStack::PushL(self);

 	self->ConstructL(aBT, aIV);

 	return self;

 	}

 CModeCBCEncryptor::CModeCBCEncryptor()

 	{

 	}

 void CModeCBCEncryptor::Transform(TDes8& aBlock)

 	{

 	assert(aBlock.Size() == iBT->BlockSize());

 	assert(iRegister.Size() == aBlock.Size());

 	XorBuf(const_cast<TUint8*>(iRegister.Ptr()), aBlock.Ptr(), aBlock.Size());

 	iBT->Transform(iRegister);

 	aBlock.Copy(iRegister);

 	}

 /* CModeCBCDecryptor */

 EXPORT_C CModeCBCDecryptor* CModeCBCDecryptor::NewL(CBlockTransformation* aBT, 

 	const TDesC8& aIV)

 	{

 	CModeCBCDecryptor* self = CModeCBCDecryptorShim::NewL(aBT, aIV);

 	if (! self)

 		{			

 		// not able to use CryptoSpi, possibly due to an exterally 

 		// derived legacy class so fallback to old implementation.			

 		self = NewLC(aBT,aIV);

 		CleanupStack::Pop(self);

 		}	

 	return self;	

 	}

 EXPORT_C CModeCBCDecryptor* CModeCBCDecryptor::NewLC(CBlockTransformation* aBT, 

 	const TDesC8& aIV)

 	{

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

 	CleanupStack::PushL(self);

 	self->ConstructL(aBT, aIV);

 	return self;	

 	}

 void CModeCBCDecryptor::ConstructL(CBlockTransformation* aBT, const TDesC8& aIV)

 	{

 	iIVBakBuf = aIV.AllocL();

 	iIVBak.Set(iIVBakBuf->Des());

 	CBlockChainingMode::ConstructL(aBT, aIV);

 	}

 CModeCBCDecryptor::~CModeCBCDecryptor(void)

 	{

 	delete iIVBakBuf;

 	}

 CModeCBCDecryptor::CModeCBCDecryptor()

 	: iIVBak(0,0,0)

 	{

 	}

 void CModeCBCDecryptor::Transform(TDes8& aBlock)

 	{

 	assert(aBlock.Size() == iBT->BlockSize());

 	assert(iRegister.Size() == aBlock.Size());

 	assert(iIVBak.Size() == aBlock.Size());

 	// Take a copy of incoming block

 	iIVBak.Copy(aBlock);

 	// transform the block

 	iBT->Transform(aBlock);

 	// xor the output with the register

 	XorBuf(const_cast<TUint8*>(aBlock.Ptr()), iRegister.Ptr(), 

 		aBlock.Size());

 	// Update the register to be the original block

 	iRegister.Copy(iIVBak);

 }