sl@0: /*
sl@0: * Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #include "rsaimpl.h"
sl@0: #include "rsafunction.h"
sl@0: #include "pluginconfig.h"
sl@0: #include <cryptopanic.h>
sl@0: #include <cryptostrength.h>
sl@0: #include <securityerr.h>
sl@0: 
sl@0: using namespace SoftwareCrypto;
sl@0: 
sl@0: /* CRSAImpl */
sl@0: CRSAImpl::CRSAImpl(
sl@0: 	TUid aCryptoMode,
sl@0: 	TUid aPadding) :
sl@0: 	CAsymmetricCipherImpl(aCryptoMode, aPadding)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: CRSAImpl* CRSAImpl::NewL(const CKey& aKey, TUid aCryptoMode, TUid aPadding)
sl@0: 	{
sl@0: 	CRSAImpl* self = CRSAImpl::NewLC(aKey, aCryptoMode, aPadding);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 	
sl@0: CRSAImpl* CRSAImpl::NewLC(const CKey& aKey, TUid aCryptoMode, TUid aPadding)
sl@0: 	{
sl@0: 	CRSAImpl* self = new(ELeave) CRSAImpl(aCryptoMode, aPadding);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL(aKey);
sl@0: 	return self;
sl@0: 	}
sl@0: 	
sl@0: CRSAImpl::~CRSAImpl()
sl@0: 	{
sl@0: 	}
sl@0: 	
sl@0: TInt CRSAImpl::GetMaximumOutputLengthL() const
sl@0: 	{
sl@0: 	const TInteger& N = iKey->GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	
sl@0: 	if (iCryptoMode.iUid == KCryptoModeDecrypt)
sl@0: 		return N.ByteCount() - iPadding->MinPaddingLength();
sl@0: 	else
sl@0: 		return N.ByteCount();
sl@0: 	}
sl@0: 	
sl@0: TInt CRSAImpl::GetMaximumInputLengthL() const
sl@0: 	{
sl@0: 	const TInteger& N = iKey->GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	
sl@0: 	if (iCryptoMode.iUid == KCryptoModeEncrypt)
sl@0: 		return N.ByteCount() - iPadding->MinPaddingLength();
sl@0: 	else
sl@0: 		return N.ByteCount();
sl@0: 	}
sl@0: 	
sl@0: void CRSAImpl::ConstructL(const CKey& aKey)
sl@0: 	{
sl@0: 	const TInteger& N = aKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	TCrypto::IsAsymmetricWeakEnoughL(N.BitCount());
sl@0: 	CAsymmetricCipherImpl::ConstructL(aKey);
sl@0: 	
sl@0: 	if (! IsValidKeyLengthL(N.ByteCount()))
sl@0: 		{
sl@0: 		User::Leave(KErrKeySize);
sl@0: 		}
sl@0: 	}
sl@0: 	
sl@0: CExtendedCharacteristics* CRSAImpl::CreateExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	// All Symbian software plug-ins have unlimited concurrency, cannot be reserved
sl@0: 	// for exclusive use and are not CERTIFIED to be standards compliant.
sl@0: 	return CExtendedCharacteristics::NewL(KMaxTInt, EFalse);
sl@0: 	}
sl@0: 	
sl@0: const CExtendedCharacteristics* CRSAImpl::GetExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	return CRSAImpl::CreateExtendedCharacteristicsL();
sl@0: 	}
sl@0: 
sl@0: TUid CRSAImpl::ImplementationUid() const
sl@0: 	{
sl@0: 	return KCryptoPluginRsaCipherUid;
sl@0: 	}
sl@0: 	
sl@0: void CRSAImpl::EncryptL(const TDesC8& aInput, TDes8& aOutput) const
sl@0: 	{
sl@0: 	__ASSERT_DEBUG(aOutput.MaxLength() >= GetMaximumOutputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));
sl@0: 	__ASSERT_DEBUG(aInput.Length() <= GetMaximumInputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge));
sl@0: 	
sl@0: 	HBufC8* buf = HBufC8::NewLC(GetMaximumOutputLengthL());
sl@0: 	TPtr8 ptr = buf->Des();
sl@0: 	
sl@0: 	iPadding->PadL(aInput, ptr);
sl@0: 	RInteger input = RInteger::NewL(ptr);
sl@0: 	CleanupStack::PushL(input);
sl@0: 	
sl@0: 	RInteger output;
sl@0: 	RSAFunction::EncryptL(*iKey, input, output);
sl@0: 	CleanupStack::PushL(output);
sl@0: 	
sl@0: 	aOutput.Append(*(output.BufferLC()));
sl@0: 	CleanupStack::PopAndDestroy(4, buf); //BufferLC, output, input, buf
sl@0: 	}
sl@0: 
sl@0: void CRSAImpl::DecryptL(const TDesC8& aInput, TDes8& aOutput) const
sl@0: 	{
sl@0: 	__ASSERT_DEBUG(aOutput.MaxLength() >= GetMaximumOutputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow));
sl@0: 	__ASSERT_DEBUG(aInput.Length() <= GetMaximumInputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge));
sl@0: 	
sl@0: 	RInteger input = RInteger::NewL(aInput);
sl@0: 	CleanupStack::PushL(input);
sl@0: 	
sl@0: 	RInteger output;
sl@0: 	
sl@0: 	RSAFunction::DecryptL(*iKey, input, output);
sl@0: 	CleanupStack::PushL(output);
sl@0: 	
sl@0: 	TPtrC8 ptr = *(output.BufferLC());
sl@0: 	iPadding->UnPadL(ptr, aOutput);
sl@0: 	
sl@0: 	CleanupStack::PopAndDestroy(3, &input); //BufferLC(), output, input
sl@0: 	}
sl@0: 
sl@0: void CRSAImpl::ProcessL(const TDesC8& aInput, TDes8& aOutput)
sl@0: 	{
sl@0: 	if (iCryptoMode.iUid == KCryptoModeEncrypt)
sl@0: 		{
sl@0: 		EncryptL(aInput, aOutput);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		DecryptL(aInput, aOutput);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: TBool CRSAImpl::IsValidKeyLengthL(TInt aKeyBytes) const
sl@0: 	{
sl@0: 	if (aKeyBytes < 1)
sl@0: 		return EFalse;
sl@0: 	
sl@0: 	switch (iCryptoMode.iUid)
sl@0: 		{
sl@0: 		case KCryptoModeEncrypt:
sl@0: 			// Check if GetMaximumInputLengthL() makes sense,
sl@0: 			// if not the key length must be too small
sl@0: 			if (GetMaximumInputLengthL() <= 0)
sl@0: 				return EFalse;
sl@0: 			break;
sl@0: 		
sl@0: 		case KCryptoModeDecrypt:
sl@0: 			// Check if GetMaximumOutputLengthL() makes sense,
sl@0: 			// if not the key length must be too small
sl@0: 			if (GetMaximumOutputLengthL() <= 0)
sl@0: 				return EFalse;
sl@0: 			break;
sl@0: 		}
sl@0: 	return ETrue;
sl@0: 	}
sl@0: