sl@0: /*
sl@0: * Copyright (c) 2003-2010 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 <asymmetric.h>
sl@0: #include <asymmetrickeys.h>
sl@0: #include <cryptospi/keys.h>
sl@0: #include "keyconverter.h"
sl@0: #include <cryptospi/cryptokeyagreementapi.h>
sl@0: #include <cryptospi/cryptospidef.h>
sl@0: 
sl@0: using namespace CryptoSpi;
sl@0: 
sl@0: CKeyAgreement* GetKeyAgreementCryptoInterfaceLC(TUid aKeyAgreementAlgoUid,
sl@0: 	  CKey& aPrivateKey, CCryptoParams* aParams)
sl@0: 	{
sl@0: 	CKeyAgreement* keyAgreementImpl =  0;
sl@0: 	CKeyAgreementFactory::CreateKeyAgreementL(keyAgreementImpl,
sl@0: 												aKeyAgreementAlgoUid, aPrivateKey,
sl@0: 												aParams);
sl@0: 	CleanupStack::PushL(keyAgreementImpl);
sl@0: 	return keyAgreementImpl;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CDH* CDH::NewL(const CDHPrivateKey& aPrivateKey)
sl@0: 	{
sl@0: 	CDH* self = CDH::NewLC(aPrivateKey);
sl@0: 	CleanupStack::Pop(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CDH* CDH::NewLC(const CDHPrivateKey& aPrivateKey)
sl@0: 	{
sl@0: 	CDH* self = new (ELeave) CDH(aPrivateKey);
sl@0: 	CleanupStack::PushL(self);
sl@0: 	return self;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* CDH::AgreeL(const CDHPublicKey& aPublicKey) const
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 ((aPublicKey.N() != iPrivateKey.N()) || (aPublicKey.G() != iPrivateKey.G()))
sl@0: 		{
sl@0: 		User::Leave(KErrArgument);
sl@0: 		}
sl@0: 
sl@0: 	CKey* privateKey = KeyConverter::CreateKeyL(iPrivateKey);
sl@0: 	CleanupStack::PushL(privateKey);
sl@0: 
sl@0: 	/*
sl@0: 	 *  package the common parameters N and G into a crypto params array
sl@0: 	 * we've already checked that both the private and public keys have the 
sl@0: 	 * same N and G so we only need build this array once for both creating 
sl@0: 	 * and calling the interface
sl@0: 	 */
sl@0: 	CCryptoParams* keyParameters = CCryptoParams::NewLC();
sl@0: 	keyParameters->AddL(aPublicKey.N(), KDhKeyParameterNUid);
sl@0: 	keyParameters->AddL(aPublicKey.G(), KDhKeyParameterGUid);
sl@0: 
sl@0: 	/* 
sl@0: 	 * get a DH key agreement interface
sl@0: 	 */
sl@0: 	CKeyAgreement* keyAgreementImpl =  GetKeyAgreementCryptoInterfaceLC(KDHAgreementUid, *privateKey, keyParameters);
sl@0: 
sl@0: 	/* 
sl@0: 	 * call the api to get a DH agreed key
sl@0: 	 */
sl@0: 	CKey* publicKey = KeyConverter::CreateKeyL(aPublicKey);
sl@0: 	CleanupStack::PushL(publicKey);
sl@0: 
sl@0: 	CKey* agreedKey = keyAgreementImpl->AgreeL(*publicKey, keyParameters);
sl@0: 	CleanupStack::PushL(agreedKey);
sl@0: 
sl@0: 	/*
sl@0: 	 * extract the agreed key
sl@0: 	 */
sl@0: 	const TInteger& agreedKeyData = agreedKey->GetBigIntL(KSymmetricKeyParameterUid);
sl@0: 	HBufC8 *agreedKeyToReturn = agreedKeyData.BufferLC();
sl@0: 	CleanupStack::Pop(agreedKeyToReturn);
sl@0: 
sl@0: 	/* 
sl@0: 	 * cleanup stack - it should contain privateKey, keyAgreementImpl, publicKey, keyParameters and agreedKey
sl@0: 	 */
sl@0: 	CleanupStack::PopAndDestroy(5, privateKey);
sl@0: 
sl@0: 	return agreedKeyToReturn;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C CDH::CDH(const CDHPrivateKey& aPrivateKey) : iPrivateKey(aPrivateKey)
sl@0: 	{
sl@0: 	}