/*

* 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 <e32std.h>

#include <random.h>

#include "pbencryptor.h"

#include "pbesymmetricfactory.h"

#ifdef SYMBIAN_ENABLE_SPLIT_HEADERS

/** The maximum block size supported (in bytes) */

const TUint KMaxBlockSizeSupported = 32;

#endif

EXPORT_C CPBEncryptorSet* CPBEncryptorSet::NewL(

	const TPBECipher aCipher, const TDesC8& aKey) 

	{

	CPBEncryptorSet* self = NewLC(aCipher, aKey);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBEncryptorSet* CPBEncryptorSet::NewLC(

	const TPBECipher aCipher, const TDesC8& aKey)

	{

	CPBEncryptorSet* self = new(ELeave) CPBEncryptorSet;

	CleanupStack::PushL(self);

	self->ConstructL(aCipher, aKey);

	return self;

	}

void CPBEncryptorSet::ConstructL(const TPBECipher aCipher,const TDesC8& aKey)

	{

	TInt blocksize = PBE::GetBlockBytes(aCipher);

	iIV = HBufC8::NewMaxL(blocksize); 

	TPtr8 iv = iIV->Des();

	TRandom::RandomL(iv);

	iCipher = PBE::MakeEncryptorL(aCipher, aKey, iv);

	}

void CPBEncryptorSet::Process(const TDesC8& aInput, TDes8& aOutput)

	{

	if(!iIVSent)

		{

		aOutput.Append(*iIV);

		iIVSent = ETrue;

		}

	iCipher->Process(aInput, aOutput);

	}

void CPBEncryptorSet::ProcessFinalL(const TDesC8& aInput, 

	TDes8& aOutput)

	{

	if(!iIVSent)

		{

		aOutput.Append(*iIV);

		iIVSent = ETrue;

		}

	iCipher->ProcessFinalL(aInput, aOutput);

	}

CPBEncryptorSet::CPBEncryptorSet() : iIVSent(EFalse)

	{

	}

CPBEncryptorSet::~CPBEncryptorSet()

	{

	delete iIV;

	delete iCipher;	//	Don't delete iCBCDecryptor, this belongs to iCipher

	}

TInt CPBEncryptorSet::MaxOutputLength(TUint aMaxInputLength) const

    {

	if(iIVSent)

		{

		return (iCipher->MaxOutputLength(aMaxInputLength));

		}

	else 

		{//	If we've not sent the iv yet then its the length 

		//	from the cipher plus a blocksize for the iv

		return (iCipher->MaxOutputLength(aMaxInputLength + iCipher->BlockSize()));

		}

    }

TInt CPBEncryptorSet::MaxFinalOutputLength(TUint aMaxInputLength) const

    {

	if(iIVSent)

		{

		return (iCipher->MaxFinalOutputLength(aMaxInputLength));

		}

	else 

		{//	If we've not sent the iv yet then its the length 

		//	from the cipher plus a blocksize for the iv

		return (iCipher->MaxFinalOutputLength(aMaxInputLength + iCipher->BlockSize()));

		}

    }

EXPORT_C CPBDecryptorSet* CPBDecryptorSet::NewL(const TPBECipher aCipher, 

	const TDesC8& aKey)

	{

	CPBDecryptorSet* self = NewLC(aCipher, aKey);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CPBDecryptorSet* CPBDecryptorSet::NewLC(const TPBECipher aCipher,

	const TDesC8& aKey)

	{

	CPBDecryptorSet* self = new(ELeave) CPBDecryptorSet;

	CleanupStack::PushL(self);

	TBuf8<KMaxBlockSizeSupported> fakeIV;

	fakeIV.SetLength(PBE::GetBlockBytes(aCipher));

	self->ConstructL(aCipher, aKey, fakeIV);

	return self;

	}

void CPBDecryptorSet::ConstructL(const TPBECipher aCipher, 

	const TDesC8& aKey, const TDesC8& aIV)

	{

	iCipher = PBE::MakeDecryptorL(aCipher, aKey, aIV);

	iIVBuf = HBufC8::NewL(PBE::GetBlockBytes(aCipher));

	}

void CPBDecryptorSet::Process(const TDesC8& aInput, TDes8& aOutput)

	{

	TPtrC8 input = ProcessIV(aInput);

	iCipher->Process(input, aOutput);

	}

void CPBDecryptorSet::ProcessFinalL(const TDesC8& aInput, TDes8& aOutput)

	{

	TPtrC8 input = ProcessIV(aInput);

	iCipher->ProcessFinalL(input, aOutput);

	}

TPtrC8 CPBDecryptorSet::ProcessIV(const TDesC8& aInput)

	{

	if(!iIVSent)

		{

		TPtr8 iIVBufPtr(iIVBuf->Des());

		if(aInput.Length() + iIVBufPtr.Length() < iCipher->BlockSize())

			{

			iIVBufPtr.Append(aInput);

			return TPtrC8();

			}

		else 

			{

			TInt rem = iCipher->BlockSize() - iIVBufPtr.Length();

			iIVBufPtr.Append(aInput.Mid(0, rem));

			CBufferedDecryptor* blockDecryptor = static_cast<CBufferedDecryptor*>(iCipher);

			static_cast<CModeCBCDecryptor*>(blockDecryptor->BlockTransformer())->SetIV(iIVBufPtr);

			iIVSent = ETrue;

			return aInput.Mid(rem);

			}

		}

	else 

		{

		return aInput;

		}

	}

CPBDecryptorSet::CPBDecryptorSet() : iIVSent(EFalse)

	{

	}

CPBDecryptorSet::~CPBDecryptorSet()

	{

	delete iCipher;

	//iCipher owns iCBCDecryptor we _don't_ need to delete it

	delete iIVBuf;

	}

TInt CPBDecryptorSet::MaxOutputLength(TUint aMaxInputLength) const

    {

	if(iIVSent)

		{

		return (iCipher->MaxOutputLength(aMaxInputLength));

		}

	else	//	if we haven't sent the iv yet, then the length the max length of the

		{	//	cipher minus a BlockSize where the IV was sitting (as the iv would be part

			//	of the length they've sent us)

		return (iCipher->MaxOutputLength(aMaxInputLength - iCipher->BlockSize()));

		}

    }

TInt CPBDecryptorSet::MaxFinalOutputLength(TUint aMaxInputLength) const

    {

	if(iIVSent)

		{

		return (iCipher->MaxFinalOutputLength(aMaxInputLength));

		}

	else	//	if we haven't sent the iv yet, then the length the max length of the

		{	//	cipher minus a BlockSize where the IV was sitting (as the iv would be part

			//	of the length they've sent us)

		return (iCipher->MaxFinalOutputLength(aMaxInputLength - iCipher->BlockSize()));

		}

    }