crypto/weakcryptospi/source/asymmetric/dhkeypairshim.cpp
changeset 19 cd501b96611d
child 43 2f10d260163b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcryptospi/source/asymmetric/dhkeypairshim.cpp	Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,153 @@
+/*
+* Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the License "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: 
+*
+*/
+
+
+#include "dhkeypairshim.h"
+#include <bigint.h>
+#include "cryptokeypairgeneratorapi.h"
+#include "keypair.h"
+#include <cryptospi/cryptoparams.h>
+#include <cryptospi/cryptospidef.h>
+
+
+using namespace CryptoSpi;
+
+
+/* CDHKeyPair */
+CDHKeyPairShim* CDHKeyPairShim::NewLC(RInteger& aN, RInteger& aG)
+	{
+	CDHKeyPairShim* self = new(ELeave) CDHKeyPairShim();
+	CleanupStack::PushL(self);
+	self->ConstructL(aN, aG);
+	return self;
+	}
+
+CDHKeyPairShim* CDHKeyPairShim::NewLC(RInteger& aN, RInteger& aG, RInteger& ax)
+	{
+	CDHKeyPairShim* self = new(ELeave) CDHKeyPairShim();
+	CleanupStack::PushL(self);
+	self->ConstructL(aN, aG, ax);
+	return self;
+	}
+
+CDHKeyPairShim::~CDHKeyPairShim(void)
+	{
+	}
+
+CDHKeyPairShim::CDHKeyPairShim(void)
+	{
+	}	
+
+void CDHKeyPairShim::ConstructL(RInteger& aN, RInteger& aG)
+	{
+	RInteger x = RInteger::NewL();
+	CleanupClosePushL(x);
+	KeyConstructorL(aN, aG, x, EFalse);
+	CleanupStack::PopAndDestroy(1, &x);
+	}
+
+void CDHKeyPairShim::ConstructL(RInteger& aN, RInteger& aG, RInteger& ax)
+	{
+	KeyConstructorL(aN, aG, ax, ETrue);
+	}
+
+void CDHKeyPairShim::KeyConstructorL(RInteger& aN, RInteger& aG, RInteger& ax, TBool xIncluded)
+	{
+	RInteger& nminus2 = aN;
+	
+	/*
+	 * do some sanity checks
+	 */
+	--nminus2;
+	--nminus2;
+	if( aG < TInteger::Two() || aG > nminus2 )
+		{
+		User::Leave(KErrArgument);
+		}
+
+	if (xIncluded)
+		{
+		if( ax < TInteger::One() || ax > nminus2 )
+			{
+			User::Leave(KErrArgument);
+			}
+		}
+
+	/*
+	 *find out how big the key should be - the key must be in the range x | 1 <= x <= n-2
+	 * nminus2 is the largest the key can be so get the number of bits required to represent that number
+	 */
+	const TInt keySize = nminus2.BitCount();
+
+	// increment aN back to its original value
+	++nminus2;
+	++nminus2;
+
+	// obtain an RSA key pair generator interface
+	
+	CKeyPairGenerator* keyPairGeneratorImpl=NULL;
+	CKeyPairGeneratorFactory::CreateKeyPairGeneratorL(
+											keyPairGeneratorImpl,
+											KDHKeyPairGeneratorUid,
+											NULL);
+	CleanupStack::PushL(keyPairGeneratorImpl);
+	
+	/* 
+	 * put the DH parameters into an array
+	 */
+	CCryptoParams* keyParameters = CCryptoParams::NewLC();
+	keyParameters->AddL(aN, KDhKeyParameterNUid);
+	keyParameters->AddL(aG, KDhKeyParameterGUid);
+	if (xIncluded)
+		{
+		// the private key x has been supplied so add it to the params array so the key generator algo can use it
+		keyParameters->AddL(ax, KDhKeyParameterxUid);
+		ax.Close();
+		}
+
+	/* 
+	 * call the api to create a DH key pair
+	 */
+	CKeyPair* keyPair = 0;
+	keyPairGeneratorImpl->GenerateKeyPairL(keySize, *keyParameters, keyPair);
+	CleanupStack::PushL(keyPair);
+
+	/* 
+	 * for compatibility convert the CKeyPair to CDHPrivateKey and CDHPublicKey
+	 */
+
+	// create new RInteger copies of aN, aG and x so the private key can own them
+	RInteger NCopy = RInteger::NewL(aN);
+	CleanupClosePushL(NCopy);
+	RInteger GCopy = RInteger::NewL(aG);
+	CleanupClosePushL(GCopy);
+	RInteger x = RInteger::NewL(keyPair->PrivateKey().GetBigIntL(KDhKeyParameterxUid));
+	CleanupClosePushL(x);
+	iPrivate = CDHPrivateKey::NewL(NCopy, GCopy, x);
+	CleanupStack::Pop(3, &NCopy);
+	
+	// the public key becomes the owner of aN, aG and X
+	RInteger X = RInteger::NewL(keyPair->PublicKey().GetBigIntL(KDhKeyParameterXUid));
+	CleanupClosePushL(X);
+	iPublic = CDHPublicKey::NewL(aN, aG, X);
+	CleanupStack::Pop(&X);	
+
+	/* 
+	 * cleanup stack - it should contain keyPairGeneratorImpl, keyParameters, keyPair, X, NCopy, GCopy and x
+	 */	
+	CleanupStack::PopAndDestroy(3, keyPairGeneratorImpl);
+	}