/*

* Copyright (c) 2003-2009 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 <asymmetric.h>

#include <asymmetrickeys.h>

#include <bigint.h>

#include <cryptostrength.h>

#include <securityerr.h>

#include <cryptopanic.h>

#include "rsafunction.h"

/* CRSAPKCS1v15Decryptor */

EXPORT_C CRSAPKCS1v15Decryptor* CRSAPKCS1v15Decryptor::NewL(

	const CRSAPrivateKey& aKey)

	{

	CRSAPKCS1v15Decryptor* self = NewLC(aKey);

	CleanupStack::Pop(self);

	return self;

	}

EXPORT_C CRSAPKCS1v15Decryptor* CRSAPKCS1v15Decryptor::NewLC(

	const CRSAPrivateKey& aKey)

	{

	CRSAPKCS1v15Decryptor* self = new(ELeave) CRSAPKCS1v15Decryptor(aKey);

	CleanupStack::PushL(self);

	self->ConstructL();

	return self;

	}

TInt CRSAPKCS1v15Decryptor::MaxInputLength(void) const

	{

	return iPrivateKey.N().ByteCount();

	}

TInt CRSAPKCS1v15Decryptor::MaxOutputLength(void) const

	{

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

	}

void CRSAPKCS1v15Decryptor::DecryptL(const TDesC8& aInput, 

	TDes8& aOutput)const

	{

	__ASSERT_DEBUG(aOutput.MaxLength() >= MaxOutputLength(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));

	__ASSERT_DEBUG(aInput.Length() <= MaxInputLength(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge));

	RInteger input = RInteger::NewL(aInput);

	CleanupStack::PushL(input);

	RInteger output;

	RSAFunction::DecryptL(iPrivateKey, input, output);

	CleanupStack::PushL(output);

    TPtrC8 ptr = *(output.BufferLC());

    iPadding->UnPadL(ptr, aOutput);

    CleanupStack::PopAndDestroy(3, &input); //BufferLC(), output, input

	}

CRSAPKCS1v15Decryptor::CRSAPKCS1v15Decryptor(const CRSAPrivateKey& aKey)  

	: iPrivateKey(aKey)

	{

	}

void CRSAPKCS1v15Decryptor::ConstructL(void)  

	{

	iPadding = CPaddingPKCS1Encryption::NewL(MaxInputLength());

	// Check if MaxInputLength() makes sense, if not the key length must 

	// be too small

	if(MaxOutputLength() <= 0)

		{

		User::Leave(KErrKeySize);

		}

	TCrypto::IsAsymmetricWeakEnoughL(iPrivateKey.N().BitCount());

	}

CRSAPKCS1v15Decryptor::~CRSAPKCS1v15Decryptor(void)  

	{

	delete iPadding;

	}