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 "desimpl.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: 
sl@0: //	bit 0 is left-most in byte
sl@0: static const TInt bytebit[] = {0200,0100,040,020,010,04,02,01};
sl@0: 
sl@0: using namespace SoftwareCrypto;
sl@0: 
sl@0: /* CDesImpl */
sl@0: CDesImpl::CDesImpl(
sl@0: 	TUint8 aBlockBytes,
sl@0: 	TUid aCryptoMode,
sl@0: 	TUid aOperationMode,
sl@0: 	TUid aPadding) :
sl@0: 	CSymmetricBlockCipherImpl(aBlockBytes, aCryptoMode, aOperationMode, aPadding)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: CDesImpl* CDesImpl::NewL(const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding)
sl@0: 	{
sl@0: 	CDesImpl* self = CDesImpl::NewLC(aKey, aCryptoMode, aOperationMode, aPadding);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 	
sl@0: CDesImpl* CDesImpl::NewLC(const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding)
sl@0: 	{
sl@0: 	CDesImpl* self = new(ELeave) CDesImpl(KDesBlockBytes, 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: CDesImpl::~CDesImpl()
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(&iK, sizeof(iK));
sl@0: 	}
sl@0: 	
sl@0: void CDesImpl::ConstructL(const CKey& aKey)
sl@0: 	{
sl@0: 	CSymmetricBlockCipherImpl::ConstructL(aKey);
sl@0: 	SetKeySchedule();
sl@0: 	}		
sl@0: 	
sl@0: CExtendedCharacteristics* CDesImpl::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* CDesImpl::GetExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	return CDesImpl::CreateExtendedCharacteristicsL();
sl@0: 	}
sl@0: 
sl@0: TUid CDesImpl::ImplementationUid() const
sl@0: 	{
sl@0: 	return KCryptoPluginDesUid;
sl@0: 	}
sl@0: 	
sl@0: TBool CDesImpl::IsValidKeyLength(TInt aKeyBytes) const
sl@0: 	{
sl@0: 	return (aKeyBytes == KDesKeyBytes);
sl@0: 	}
sl@0: 	
sl@0: TInt CDesImpl::GetKeyStrength() const
sl@0: 	{
sl@0: 	// parity bits are excluded
sl@0: 	return BytesToBits(KDesKeyBytes - 8);
sl@0: 	}	
sl@0: 	
sl@0: void CDesImpl::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: 		TUint32 l, r;
sl@0: 		// Split the block into 2 word-sized big endian portions
sl@0: 		GetBlockBigEndian(aBuffer, l, r);
sl@0: 		IPerm(l,r);
sl@0: 		DoTransform(l, r, iK);		
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: 
sl@0: 		ModeEncryptEnd(aBuffer);
sl@0: 		aBuffer += KDesBlockBytes;
sl@0: 		}
sl@0: 	}	
sl@0: 	
sl@0: void CDesImpl::TransformDecrypt(
sl@0: 	TUint8* aBuffer,
sl@0: 	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: 		DoTransform(l, r, iK);		
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: 
sl@0: 		ModeDecryptEnd(aBuffer);
sl@0: 		aBuffer += KDesBlockBytes;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void CDesImpl::SetKeySchedule()
sl@0: 	{
sl@0: 	if (iCryptoMode.iUid == KCryptoModeEncrypt)
sl@0: 		{
sl@0: 		SetEncryptKeySchedule(*iKey, iK);
sl@0: 		}
sl@0: 	else 
sl@0: 		{
sl@0: 		ASSERT(iCryptoMode.iUid == KCryptoModeDecrypt);
sl@0: 		SetDecryptKeySchedule(*iKey, iK);
sl@0: 		}	
sl@0: 	}		
sl@0: 
sl@0: void CDesImpl::DoTransform(TUint32& l, TUint32& r, const TUint32* aKeySchedule)
sl@0: 	{
sl@0: 	TInt i = 0;
sl@0: 	for (; i<8; i++)
sl@0: 		{
sl@0: 		TUint32 work = rotrFixed(r, 4U) ^ aKeySchedule[4*i+0];
sl@0: 		l ^= DES_TABLE::sbox[6][(work) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[4][(work >> 8) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[2][(work >> 16) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[0][(work >> 24) & 0x3f];
sl@0: 		work = r ^ aKeySchedule[4*i+1];
sl@0: 		l ^= DES_TABLE::sbox[7][(work) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[5][(work >> 8) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[3][(work >> 16) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[1][(work >> 24) & 0x3f];
sl@0: 
sl@0: 		work = rotrFixed(l, 4U) ^ aKeySchedule[4*i+2];
sl@0: 		r ^= DES_TABLE::sbox[6][(work) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[4][(work >> 8) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[2][(work >> 16) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[0][(work >> 24) & 0x3f];
sl@0: 		work = l ^ aKeySchedule[4*i+3];
sl@0: 		r ^= DES_TABLE::sbox[7][(work) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[5][(work >> 8) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[3][(work >> 16) & 0x3f]
sl@0: 		  ^  DES_TABLE::sbox[1][(work >> 24) & 0x3f];
sl@0: 		}
sl@0: 	}	
sl@0: 
sl@0: void CDesImpl::SetEncryptKeySchedule(const TDesC8& aKey, TUint32* aKeySchedule)
sl@0: 	{
sl@0: 	TInt i=0, j=0, l=0, m=0;
sl@0: 
sl@0: //	Form a byte array from aKey, taking endianess into account (little->big)	
sl@0: 	TUint8 key[8];								//	For big endian byte array	
sl@0: 	Mem::Copy(&key, &aKey[0], 8);
sl@0: 
sl@0: 	TUint8 buffer[56+56+8];
sl@0: 	TUint8* const pc1m = &buffer[0];			/* place to modify pc1 into */
sl@0: 	TUint8* const pcr = pc1m + 56;				/* place to rotate pc1 into */
sl@0: 	TUint8* const ks = pcr + 56;
sl@0: 
sl@0: 	for (j=0; j<56; j++) 
sl@0: 		{/* convert pc1 to bits of key */
sl@0: 		l = DES_TABLE::pc1[j]-1;				/* integer bit location  */
sl@0: 		m = l & 07;								/* find bit              */
sl@0: 		pc1m[j]=(key[l>>3] &					/* find which key byte l is in */
sl@0: 			bytebit[m])							/* and which bit of that byte */
sl@0: 			? (TUint8)1 : (TUint8)0;			/* and store 1-bit result */
sl@0: 		}
sl@0: 
sl@0: 	for (i=0; i<16; i++) 
sl@0: 		{/* key chunk for each iteration */
sl@0: 		Mem::FillZ(ks,8);							/* Clear key schedule */
sl@0: 		for (j=0; j<56; j++)
sl@0: 		/*	rotate pc1 the right amount */
sl@0: 			pcr[j] = pc1m[(l=j+DES_TABLE::totrot[i])<(j<28? 28 : 56) ? l: l-28];
sl@0: 		
sl@0: 		/* rotate left and right halves independently */
sl@0: 		
sl@0: 		for (j=0; j<48; j++)
sl@0: 			{/* select bits individually */
sl@0: 			/* check bit that goes to ks[j] */
sl@0: 			if (pcr[DES_TABLE::pc2[j]-1])
sl@0: 				{/* mask it in if it's there */
sl@0: 				l= j % 6;
sl@0: 				ks[j/6] |= bytebit[l] >> 2;
sl@0: 				}
sl@0: 			}
sl@0: 
sl@0: 		/* Now convert to odd/even interleaved form for use in F */
sl@0: 		(*(aKeySchedule+(2*i))) = ((TUint32)ks[0] << 24)
sl@0: 			| ((TUint32)ks[2] << 16)
sl@0: 			| ((TUint32)ks[4] << 8)
sl@0: 			| ((TUint32)ks[6]);
sl@0: 		
sl@0: 		(*(aKeySchedule+(2*i+1))) = ((TUint32)ks[1] << 24)
sl@0: 			| ((TUint32)ks[3] << 16)
sl@0: 			| ((TUint32)ks[5] << 8)
sl@0: 			| ((TUint32)ks[7]);
sl@0: 		}		
sl@0: 	}
sl@0: 
sl@0: void CDesImpl::SetDecryptKeySchedule(const TDesC8& aKey, TUint32* aKeySchedule)
sl@0: 	{
sl@0: 	SetEncryptKeySchedule(aKey, aKeySchedule);
sl@0: 	ReverseKeySchedule(aKeySchedule);
sl@0: 	}