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 "dhimpl.h"
sl@0: #include "pluginconfig.h"
sl@0: 
sl@0: using namespace SoftwareCrypto;
sl@0: using namespace CryptoSpi;
sl@0: 
sl@0: /* CDHImpl */
sl@0: CDHImpl::CDHImpl()
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: CDHImpl::~CDHImpl()
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: CDHImpl* CDHImpl::NewL(const CKey& aPrivateKey, const CCryptoParams* aParams)
sl@0: 	{
sl@0: 	CDHImpl* self = CDHImpl::NewLC(aPrivateKey, aParams);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: CDHImpl* CDHImpl::NewLC(const CKey& aPrivateKey, const CCryptoParams* aParams)
sl@0: 	{
sl@0: 	CDHImpl* self = new(ELeave) CDHImpl();
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL(aPrivateKey, aParams);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: CKey* CDHImpl::AgreeL(const CKey& aOtherPublicKey, const CCryptoParams* aParams)
sl@0: 	{
sl@0: 	/*
sl@0: 	 * unpack the parameters, we're expecting the N and G parameters
sl@0: 	 */
sl@0: 	const TInteger& N = aParams->GetBigIntL(KDhKeyParameterNUid);
sl@0: 	const TInteger& G = aParams->GetBigIntL(KDhKeyParameterGUid);
sl@0: 	const TInteger& privateN = iSharedParams->GetBigIntL(KDhKeyParameterNUid);
sl@0: 	const TInteger& privateG = iSharedParams->GetBigIntL(KDhKeyParameterGUid);
sl@0: 	const TInteger& X = aOtherPublicKey.GetBigIntL(KDhKeyParameterXUid);
sl@0: 	const TInteger& x = iPrivateKey->GetBigIntL(KDhKeyParameterxUid);
sl@0: 
sl@0: 	/*
sl@0: 	 * both DH keys (ie our private and their public keys) must use the same N and G parameters
sl@0: 	 */
sl@0: 	if ((N != privateN) || (G != privateG))
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 
sl@0: 	/*
sl@0: 	 * do the key agreement algo X ^ x mod N
sl@0: 	 */
sl@0: 	RInteger result = TInteger::ModularExponentiateL(X, x, N);
sl@0: 	CleanupClosePushL(result);
sl@0: 
sl@0: 	/*
sl@0: 	 * create the agreed key
sl@0: 	 */
sl@0: 	CCryptoParams* agreedKeyParameters = CCryptoParams::NewLC();
sl@0: 	agreedKeyParameters->AddL(result, KSymmetricKeyParameterUid);
sl@0: 	TKeyProperty agreedKeyProperties = {KDHAgreementUid, KCryptoPluginDhKeyAgreementUid,
sl@0: 									KDHAgreedKeyUid, KNonEmbeddedKeyUid };
sl@0: 	CKey* agreedKey = CKey::NewL(agreedKeyProperties, *agreedKeyParameters);
sl@0: 
sl@0: 	// cleanup result, agreedKeyParameters
sl@0: 	CleanupStack::PopAndDestroy(2, &result);
sl@0: 	return agreedKey;
sl@0: 	}
sl@0: 
sl@0: TUid CDHImpl::ImplementationUid() const
sl@0: 	{
sl@0: 	return KCryptoPluginDhKeyAgreementUid;
sl@0: 	}
sl@0: 
sl@0: CExtendedCharacteristics* CDHImpl::CreateExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	// All Symbian software plug-ins have unlimited concurrency, cannot be
sl@0: 	// reserved 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* CDHImpl::GetExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	return CDHImpl::CreateExtendedCharacteristicsL();
sl@0: 	}
sl@0: