/*

* 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);

}