author | sl@SLION-WIN7.fritz.box |
Fri, 15 Jun 2012 03:10:57 +0200 | |
changeset 0 | bde4ae8d615e |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). |
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* All rights reserved. |
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* This component and the accompanying materials are made available |
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* under the terms of the License "Eclipse Public License v1.0" |
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* which accompanies this distribution, and is available |
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* at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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* |
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* Initial Contributors: |
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* Nokia Corporation - initial contribution. |
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* |
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* Contributors: |
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* |
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* Description: |
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* |
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*/ |
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|
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|
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#include "arc4impl.h" |
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#include "keys.h" |
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#include "pluginconfig.h" |
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#include "symmetriccipherimpl.h" |
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#include <cryptostrength.h> |
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#include "common/inlines.h" |
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|
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|
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using namespace SoftwareCrypto; |
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|
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CArc4Impl* CArc4Impl::NewL(const CKey& aKey, TInt aDiscardBytes) |
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{ |
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CArc4Impl* self = CArc4Impl::NewLC(aKey, aDiscardBytes); |
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CleanupStack::Pop(self); |
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return self; |
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} |
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|
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CArc4Impl* CArc4Impl::NewLC(const CKey& aKey, TInt aDiscardBytes) |
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{ |
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CArc4Impl* self = new(ELeave) CArc4Impl(aDiscardBytes); |
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CleanupStack::PushL(self); |
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self->ConstructL(aKey); |
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|
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const TDesC8& keyContent = aKey.GetTDesC8L(KSymmetricKeyParameterUid); |
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TCrypto::IsSymmetricWeakEnoughL(BytesToBits(keyContent.Size()) - keyContent.Size()); |
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|
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return self; |
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} |
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|
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CArc4Impl::CArc4Impl(TInt aDiscardBytes) |
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:ix(1), iy(0), iDiscardBytes(aDiscardBytes) |
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{ |
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} |
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|
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CArc4Impl::~CArc4Impl() |
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{ |
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} |
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|
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void CArc4Impl::ConstructL(const CKey& aKey) |
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{ |
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CSymmetricStreamCipherImpl::ConstructL(aKey); |
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GenerateSBox(); |
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} |
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|
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CExtendedCharacteristics* CArc4Impl::CreateExtendedCharacteristicsL() |
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{ |
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// All Symbian software plug-ins have unlimited concurrency, cannot be reserved |
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// for exclusive use and are not CERTIFIED to be standards compliant. |
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return CExtendedCharacteristics::NewL(KMaxTInt, EFalse); |
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} |
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|
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const CExtendedCharacteristics* CArc4Impl::GetExtendedCharacteristicsL() |
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{ |
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return CArc4Impl::CreateExtendedCharacteristicsL(); |
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} |
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|
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void CArc4Impl::DoProcess(TDes8& aData) |
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{ |
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TInt blockLen = aData.Size(); |
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|
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if (blockLen > 0) |
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{ |
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TUint8* blockPtr = (TUint8*)&aData[0]; |
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do |
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{ |
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*blockPtr++ ^= GenerateByte(); |
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} |
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while (--blockLen); |
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} |
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} |
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|
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TBool CArc4Impl::IsValidKeyLength(TInt aKeyBytes) const |
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{ |
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return ((aKeyBytes > 0 && aKeyBytes <= KMaxARC4KeyBytes) ? ETrue : EFalse); |
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} |
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|
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void CArc4Impl::Reset() |
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{ |
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ix = 1; |
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iy = 0; |
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GenerateSBox(); |
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} |
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|
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TUid CArc4Impl::ImplementationUid() const |
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{ |
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return KCryptoPluginArc4Uid; |
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} |
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|
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TUint8 CArc4Impl::GenerateByte() |
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{ |
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TUint8 a = iState[ix]; |
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iy = (TUint8)((iy + a) & 0xff); |
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TUint8 b = iState[iy]; |
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|
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iState[ix] = b; |
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iState[iy] = a; |
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ix = (TUint8)((ix + 1) & 0xff); |
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return (iState[(a + b) & 0xff]); |
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} |
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|
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void CArc4Impl::DiscardBytes(TInt aDiscardBytes) |
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{ |
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if (aDiscardBytes > 0) |
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{ |
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do |
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{ |
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GenerateByte(); |
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} |
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while(--aDiscardBytes); |
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} |
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} |
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|
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void CArc4Impl::GenerateSBox(void) |
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{ |
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TUint keyBytes = iKey->Size(); |
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|
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TInt i = 0; |
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for (; i < KSBoxSize; i++) |
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iState[i] = (TUint8)i; |
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|
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TUint keyIndex = 0, stateIndex = 0; |
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i = 0; |
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for (; i < KSBoxSize; i++) |
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{ |
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TUint a = iState[i]; |
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stateIndex += (*iKey)[keyIndex] + a; |
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stateIndex &= 0xff; |
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iState[i] = iState[stateIndex]; |
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iState[stateIndex] = (TUint8)a; |
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if (++keyIndex >= (TUint)keyBytes) |
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keyIndex = 0; |
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} |
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|
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DiscardBytes(iDiscardBytes); |
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} |