/*

* Copyright (c) 2006-2009 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 "rsaverifyimpl.h"

#include "pluginconfig.h"

#include "rsafunction.h"

using namespace SoftwareCrypto;

// Implementation of CRSAVerifierImpl

CRSAVerifierImpl* CRSAVerifierImpl::NewL(const CKey& aKey, TUid aPaddingMode)

	{

	CRSAVerifierImpl* self = CRSAVerifierImpl::NewLC(aKey, aPaddingMode);

	CleanupStack::Pop(self);

	return self;

	}

CRSAVerifierImpl* CRSAVerifierImpl::NewLC(const CKey& aKey, TUid aPaddingMode)

	{

	CRSAVerifierImpl* self = new(ELeave) CRSAVerifierImpl(aPaddingMode);

	CleanupStack::PushL(self);

	self->ConstructL(aKey);

	return self;

	}

CRSAVerifierImpl::CRSAVerifierImpl(TUid aPaddingMode)

	: iPaddingMode(aPaddingMode)

	{

	}

CRSAVerifierImpl::~CRSAVerifierImpl()

	{

	delete iPadding;

	}

void CRSAVerifierImpl::ConstructL(const CKey& aKey)

	{

	CVerifierImpl::ConstructL(aKey);

	SetPaddingModeL(iPaddingMode);

	}

CExtendedCharacteristics* CRSAVerifierImpl::CreateExtendedCharacteristicsL()

	{

	// All Symbian software plug-ins have unlimited concurrency, cannot be reserved

	// for exclusive use and are not CERTIFIED to be standards compliant.

	return CExtendedCharacteristics::NewL(KMaxTInt, EFalse);

	}

const CExtendedCharacteristics* CRSAVerifierImpl::GetExtendedCharacteristicsL()

	{

	return CRSAVerifierImpl::CreateExtendedCharacteristicsL();

	}

TUid CRSAVerifierImpl::ImplementationUid() const

	{

	return KCryptoPluginRsaVerifierUid;

	}

void CRSAVerifierImpl::SetPaddingModeL(TUid aPaddingMode) 

	{

	CPadding* padding(0);

	switch (aPaddingMode.iUid)

		{

		case KPaddingModeNone:

			padding = CPaddingNone::NewL(GetMaximumOutputLengthL());

			break;

		case KPaddingModePkcs1_v1_5_Signature:

			padding = CPaddingPKCS1Signature::NewL(GetMaximumOutputLengthL());

			break;

		default:

			User::Leave(KErrNotSupported);

		}

	delete iPadding;

	iPadding = padding;

	iPaddingMode = aPaddingMode;

	Reset();	

	}

void CRSAVerifierImpl::SetKeyL(const CKey& aPublicKey)

	{

	DoSetKeyL(aPublicKey);

	Reset();	

	}

TInt CRSAVerifierImpl::GetMaximumInputLengthL() const

	{

	return GetMaximumOutputLengthL() - iPadding->MinPaddingLength();	

	}

TInt CRSAVerifierImpl::GetMaximumOutputLengthL() const

	{

	const TInteger& paramN = iKey->GetBigIntL(KRsaKeyParameterNUid);

	return paramN.ByteCount();	

	}

void CRSAVerifierImpl::VerifyL(const TDesC8& aInput, const CCryptoParams& aSignature, TBool& aVerificationResult)

	{

	HBufC8* output = NULL;

	InverseSignL(output, aSignature);

	CleanupStack::PushL(output);

	// is the original hash the same as the hash extracted from the signature

	aVerificationResult = EFalse;

	if (!output->Compare(aInput))

		{

		aVerificationResult = ETrue;

		}

	CleanupStack::PopAndDestroy(output);

	}

void CRSAVerifierImpl::InverseSignL(HBufC8*& aOutput, const CCryptoParams& aSignature)

	{

	// extract the original hash from the signature

	const TInteger& signature = aSignature.GetBigIntL(KRsaSignatureParameterSUid);

	RInteger output;

	RSAFunction::VerifyL(*iKey, signature, output);

	CleanupClosePushL(output);

	// format the extracted hash so it can be compared with the original hash

	HBufC8* paddedHashPtr = output.BufferLC();

	aOutput = HBufC8::NewLC(GetMaximumOutputLengthL());

	TPtr8 unpaddedHash = aOutput->Des();

	iPadding->UnPadL(*paddedHashPtr, unpaddedHash);

	CleanupStack::Pop(aOutput);

	CleanupStack::PopAndDestroy(2, &output);

	}