sl@0: /*
sl@0: * Copyright (c) 2007-2010 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 "dhkeypairgenimpl.h"
sl@0: #include "pluginconfig.h"
sl@0: #include <cryptospi/keypair.h>
sl@0: 
sl@0: using namespace SoftwareCrypto;
sl@0: using namespace CryptoSpi;
sl@0: 
sl@0: /* CDHKeyPairGenImpl */
sl@0: CDHKeyPairGenImpl::CDHKeyPairGenImpl(TUid aImplementationUid) : CKeyPairGenImpl(aImplementationUid)
sl@0: 	{
sl@0: 	
sl@0: 	}
sl@0: 
sl@0: CDHKeyPairGenImpl::~CDHKeyPairGenImpl()
sl@0: 	{
sl@0: 	
sl@0: 	}
sl@0: 
sl@0: CDHKeyPairGenImpl* CDHKeyPairGenImpl::NewL(TUid aImplementationUid)
sl@0: 	{
sl@0: 	CDHKeyPairGenImpl* self = CDHKeyPairGenImpl::NewLC(aImplementationUid);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: CDHKeyPairGenImpl* CDHKeyPairGenImpl::NewLC(TUid aImplementationUid)
sl@0: 	{
sl@0: 	CDHKeyPairGenImpl* self = new(ELeave) CDHKeyPairGenImpl(aImplementationUid);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	self->ConstructL();
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: void CDHKeyPairGenImpl::ConstructL(void)
sl@0: 	{
sl@0: 	CKeyPairGenImpl::ConstructL();
sl@0: 	}
sl@0: 
sl@0: CExtendedCharacteristics* CDHKeyPairGenImpl::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* CDHKeyPairGenImpl::GetExtendedCharacteristicsL()
sl@0: 	{
sl@0: 	return CDHKeyPairGenImpl::CreateExtendedCharacteristicsL();
sl@0: 	}
sl@0: 
sl@0: TUid CDHKeyPairGenImpl::ImplementationUid() const
sl@0: 	{
sl@0: 	return iImplementationUid;
sl@0: 	}
sl@0: 
sl@0: void CDHKeyPairGenImpl::Reset()
sl@0: 	{
sl@0: 	// does nothing in this plugin
sl@0: 	}
sl@0: 
sl@0: void CDHKeyPairGenImpl::GenerateKeyPairL(TInt /*aKeySize*/, const CCryptoParams& aKeyParameters, CKeyPair*& aKeyPair)
sl@0: 	{
sl@0: 	/*
sl@0: 	 * unpack the parameters, we're expecting the N and G parameters and if present the x parameter (aka private key)
sl@0: 	 */
sl@0: 	const TInteger& N = aKeyParameters.GetBigIntL(KDhKeyParameterNUid);
sl@0: 	const TInteger& G = aKeyParameters.GetBigIntL(KDhKeyParameterGUid);
sl@0: 
sl@0: 	/*
sl@0: 	 * do some sanity checking
sl@0: 	 */
sl@0: 	RInteger nminus2 = RInteger::NewL(N);
sl@0: 	CleanupStack::PushL(nminus2);
sl@0: 	--nminus2;
sl@0: 	--nminus2;
sl@0: 
sl@0: 	if ((G < TInteger::Two()) || (G > nminus2))
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 
sl@0: 	/*
sl@0: 	 * has a private key x been supplied? if not then generate it
sl@0: 	 */
sl@0: 	RInteger x;
sl@0: 	if (aKeyParameters.IsPresent(KDhKeyParameterxUid))
sl@0: 		{
sl@0: 		x = RInteger::NewL(aKeyParameters.GetBigIntL(KDhKeyParameterxUid));
sl@0: 		}
sl@0: 		else
sl@0: 		{
sl@0: 		// find a random x | 1 <= x <= n-2
sl@0: 		x = RInteger::NewRandomL(TInteger::One(), nminus2);
sl@0: 		}
sl@0: 	CleanupClosePushL(x);
sl@0: 	/*
sl@0: 	 * generate the public key with X = G^(x) mod N
sl@0: 	 */
sl@0: 	RInteger X = TInteger::ModularExponentiateL(G, x, N);
sl@0: 	CleanupClosePushL(X);
sl@0: 
sl@0: 	/*
sl@0: 	 * create the keys parameters
sl@0: 	  */
sl@0: 	CCryptoParams* publicKeyParameters = CCryptoParams::NewLC();
sl@0: 	publicKeyParameters->AddL(X, KDhKeyParameterXUid);
sl@0: 	TKeyProperty publicKeyProperties = {KDHKeyPairGeneratorUid, iImplementationUid, 
sl@0: 									KDHPublicKeyUid, KNonEmbeddedKeyUid };
sl@0: 	CCryptoParams* privateKeyParameters = CCryptoParams::NewLC();
sl@0: 	privateKeyParameters->AddL(x, KDhKeyParameterxUid);
sl@0: 	TKeyProperty privateKeyProperties = {KDHKeyPairGeneratorUid, iImplementationUid,
sl@0: 									KDHPrivateKeyUid, KNonEmbeddedKeyUid };
sl@0: 
sl@0: 	/*
sl@0: 	 * create the public key
sl@0: 	 */
sl@0: 	CKey* publicKey = CKey::NewL(publicKeyProperties, *publicKeyParameters);
sl@0: 	CleanupStack::PushL(publicKey);
sl@0: 
sl@0: 	/*
sl@0: 	 * create the private key
sl@0: 	 */
sl@0: 	CKey* privateKey = CKey::NewL(privateKeyProperties, *privateKeyParameters);
sl@0: 	CleanupStack::PushL(privateKey);
sl@0: 
sl@0: 	/*
sl@0: 	 * create the key pair
sl@0: 	 */
sl@0: 	aKeyPair = CKeyPair::NewL(publicKey, privateKey);
sl@0: 	
sl@0: 	/* 
sl@0: 	 * cleanup stack - it should contain nminus2, x (if allocated here), X, publicKeyParameters, privateKeyParameters, publicKey and privateKey
sl@0: 	 */
sl@0: 	CleanupStack::Pop(2, publicKey);
sl@0: 	CleanupStack::PopAndDestroy(5, &nminus2);
sl@0: 	}