/*

 * 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);

 	}