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 "3desimpl.h"
sl@0: 
sl@0: #include "destables.h"
sl@0: #include "common/inlines.h"
sl@0: #include "des.inl"
sl@0: #include "pluginconfig.h"
sl@0: #include "symmetriccipherimpl.h"
sl@0: #include <cryptostrength.h>
sl@0: 
sl@0: using namespace SoftwareCrypto;
sl@0: 
sl@0: /* C3DesImpl */
sl@0: C3DesImpl::C3DesImpl(
sl@0: 	TUid aCryptoMode,
sl@0: 	TUid aOperationMode,
sl@0: 	TUid aPadding) :
sl@0: 	CDesImpl(KDesBlockBytes, aCryptoMode, aOperationMode, aPadding)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: C3DesImpl* C3DesImpl::NewL(const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding)
sl@0: 	{
sl@0: 	C3DesImpl* self = C3DesImpl::NewLC(aKey, aCryptoMode, aOperationMode, aPadding);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 	
sl@0: C3DesImpl* C3DesImpl::NewLC(const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding)
sl@0: 	{
sl@0: 	C3DesImpl* self = new(ELeave) C3DesImpl(aCryptoMode, aOperationMode, aPadding);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL(aKey);
sl@0: 
sl@0: 	const TDesC8& keyContent = aKey.GetTDesC8L(KSymmetricKeyParameterUid);
sl@0: 	TCrypto::IsSymmetricWeakEnoughL(BytesToBits(keyContent.Size()) - keyContent.Size());
sl@0: 	return self;
sl@0: 	}
sl@0: 		
sl@0: C3DesImpl::~C3DesImpl()
sl@0: 	{
sl@0: 	// make sure key information isn't visible to other processes if the
sl@0: 	// page is reused.
sl@0: 	Mem::FillZ(&iK1, sizeof(iK1));
sl@0: 	Mem::FillZ(&iK2, sizeof(iK2));
sl@0: 	Mem::FillZ(&iK3, sizeof(iK3));
sl@0: 	}
sl@0: 	
sl@0: void C3DesImpl::ConstructL(const CKey& aKey)
sl@0: 	{
sl@0: 	CDesImpl::ConstructL(aKey);
sl@0: 	SetKeySchedule();
sl@0: 	}	
sl@0: 	
sl@0: CExtendedCharacteristics* C3DesImpl::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* C3DesImpl::GetExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	return C3DesImpl::CreateExtendedCharacteristicsL();
sl@0: 	}
sl@0: 
sl@0: TUid C3DesImpl::ImplementationUid() const
sl@0: 	{
sl@0: 	return KCryptoPlugin3DesUid;
sl@0: 	}
sl@0: 	
sl@0: TBool C3DesImpl::IsValidKeyLength(TInt aKeyBytes) const
sl@0: 	{
sl@0: 	return (aKeyBytes == K3DesKeyBytes);
sl@0: 	}
sl@0: 	
sl@0: TInt C3DesImpl::GetKeyStrength() const
sl@0: 	{
sl@0: 	// Exclude parity bits from each subkey
sl@0: 	return BytesToBits(K3DesKeyBytes - (3 * 8));
sl@0: 	}	
sl@0: 	
sl@0: void C3DesImpl::TransformEncrypt(
sl@0: 	TUint8* aBuffer,
sl@0: 	TUint aNumBlocks)
sl@0: 	{			
sl@0: 	for (TInt i = 0; i < aNumBlocks; ++i)
sl@0: 		{		
sl@0: 		ModeEncryptStart(aBuffer);
sl@0: 
sl@0: 		TUint32 l, r;
sl@0: 		// Split the block into 2 word-sized big endian portions
sl@0: 		GetBlockBigEndian(aBuffer, l, r);
sl@0: 
sl@0: 		IPerm(l,r);
sl@0: 		// The mode is applied to the entire operation and NOT 
sl@0: 		// for each DES transform
sl@0: 		TUid opMode = iOperationMode;
sl@0: 		iOperationMode = KOperationModeECBUid;
sl@0: 		DoTransform(l, r, iK1);
sl@0: 		DoTransform(r, l, iK2);
sl@0: 		DoTransform(l, r, iK3);
sl@0: 		iOperationMode = opMode;
sl@0: 		FPerm(l,r);
sl@0: 
sl@0: 		// Put the portions back into the block as little endian
sl@0: 		PutBlockBigEndian(aBuffer, r, l);
sl@0: 		ModeEncryptEnd(aBuffer);
sl@0: 		aBuffer += KDesBlockBytes;
sl@0: 		}
sl@0: 	}
sl@0: 	
sl@0: void C3DesImpl::TransformDecrypt(
sl@0: 	TUint8* aBuffer,
sl@0: 	const TUint aNumBlocks)
sl@0: 	{	
sl@0: 	for (TInt i = 0; i < aNumBlocks; ++i)
sl@0: 		{		
sl@0: 		ModeDecryptStart(aBuffer);
sl@0: 			
sl@0: 		TUint32 l, r;
sl@0: 		// Split the block into 2 word-sized big endian portions
sl@0: 		GetBlockBigEndian(aBuffer, l, r);
sl@0: 
sl@0: 		IPerm(l,r);
sl@0: 		
sl@0: 		// The mode is applied to the entire operation and NOT 
sl@0: 		// for each DES transform
sl@0: 		TUid opMode = iOperationMode;
sl@0: 		iOperationMode = KOperationModeECBUid;
sl@0: 		DoTransform(l, r, iK1);
sl@0: 		DoTransform(r, l, iK2);
sl@0: 		DoTransform(l, r, iK3);
sl@0: 		iOperationMode = opMode;
sl@0: 		FPerm(l,r);
sl@0: 
sl@0: 		// Put the portions back into the block as little endian
sl@0: 		PutBlockBigEndian(aBuffer, r, l);	
sl@0: 		ModeDecryptEnd(aBuffer);
sl@0: 		aBuffer += K3DesBlockBytes;
sl@0: 		}
sl@0: 	}	
sl@0: 
sl@0: void C3DesImpl::SetKeySchedule()
sl@0: 	{
sl@0: 	if (iCryptoMode.iUid == KCryptoModeEncrypt)
sl@0: 		{
sl@0: 		// Encrypt -> Decrypt -> Encrypt
sl@0: 		// Encryptor key	
sl@0: 		SetEncryptKeySchedule(iKey->Mid(0, KDesKeyBytes), iK1);
sl@0: 		
sl@0: 		// Decryptor key
sl@0: 		SetDecryptKeySchedule(iKey->Mid(KDesKeyBytes, 2 * KDesKeyBytes), iK2);
sl@0: 		
sl@0: 		// Encryptor key
sl@0: 		SetEncryptKeySchedule(iKey->Mid(2 * KDesKeyBytes), iK3);
sl@0: 		}
sl@0: 	else 
sl@0: 		{
sl@0: 		// Decrypt -> Encrypt -> Decrypt
sl@0: 		// Key order is reversed !
sl@0: 		
sl@0: 		ASSERT(iCryptoMode.iUid == KCryptoModeDecrypt);
sl@0: 		// Decryptor key	
sl@0: 		SetDecryptKeySchedule(iKey->Mid(0, KDesKeyBytes), iK3);
sl@0: 		
sl@0: 		// Encryptor key
sl@0: 		SetEncryptKeySchedule(iKey->Mid(KDesKeyBytes, 2 * KDesKeyBytes), iK2);
sl@0: 		
sl@0: 		// Decryptor key
sl@0: 		SetDecryptKeySchedule(iKey->Mid(2 * KDesKeyBytes), iK1);
sl@0: 		}	
sl@0: 	}