--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cryptoplugins/cryptospiplugins/source/softwarecrypto/dsaverifyimpl.cpp	Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,160 @@
+/*
+* Copyright (c) 2006-2009 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 "dsaverifyimpl.h"
+#include "pluginconfig.h"
+
+using namespace SoftwareCrypto;
+
+// Implementation of CDSAVerifierImpl
+CDSAVerifierImpl* CDSAVerifierImpl::NewL(const CKey& aKey)
+	{
+	CDSAVerifierImpl* self = CDSAVerifierImpl::NewLC(aKey);
+	CleanupStack::Pop(self);
+	return self;
+	}
+	
+CDSAVerifierImpl* CDSAVerifierImpl::NewLC(const CKey& aKey)
+	{
+	CDSAVerifierImpl* self = new(ELeave) CDSAVerifierImpl();
+	CleanupStack::PushL(self);
+	self->ConstructL(aKey);
+	return self;
+	}
+	
+CDSAVerifierImpl::CDSAVerifierImpl() 
+	{
+	}
+
+CDSAVerifierImpl::~CDSAVerifierImpl()
+	{
+	}
+	
+void CDSAVerifierImpl::ConstructL(const CKey& aKey)
+	{
+	CVerifierImpl::ConstructL(aKey);
+	}
+	
+CExtendedCharacteristics* CDSAVerifierImpl::CreateExtendedCharacteristicsL()
+	{
+	// All Symbian software plug-ins have unlimited concurrency, cannot be reserved
+	// for exclusive use and are not CERTIFIED to be standards compliant.
+	return CExtendedCharacteristics::NewL(KMaxTInt, EFalse);
+	}
+	
+const CExtendedCharacteristics* CDSAVerifierImpl::GetExtendedCharacteristicsL()
+	{
+	return CDSAVerifierImpl::CreateExtendedCharacteristicsL();
+	}
+	
+TUid CDSAVerifierImpl::ImplementationUid() const
+	{
+	return KCryptoPluginDsaVerifierUid;
+	}
+	
+void CDSAVerifierImpl::SetKeyL(const CKey& aPublicKey)
+	{
+	DoSetKeyL(aPublicKey);
+	Reset();	
+	}
+
+TInt CDSAVerifierImpl::GetMaximumInputLengthL() const
+	{
+	return KSha1HashLength;
+	}
+
+void CDSAVerifierImpl::VerifyL(const TDesC8& aInput, const CCryptoParams& aSignature, TBool& aVerificationResult)
+	{
+	//Retrieve the parameter Q from the key	
+	const TInteger& tQ=iKey->GetBigIntL(KDsaKeyParameterQUid);
+
+	//see HAC 11.56 or DSS section 6
+	//I'll follow HAC as I like the description better
+
+	// a) Obtain A's authenticate public key
+
+	// b) Verify that 0 < r < q and 0 < s < q; if not reject signature
+
+	//Retrieve the R&S in DSA signature from the array
+
+	const TInteger& tR=aSignature.GetBigIntL(KDsaSignatureParameterRUid);
+	const TInteger& tS=aSignature.GetBigIntL(KDsaSignatureParameterSUid);
+
+	if (tR <= 0 || tR >= tQ)
+		{
+		aVerificationResult=EFalse;
+		return;
+		}
+	if (tS <= 0 || tS >= tQ)
+		{
+		aVerificationResult=EFalse;
+		return;
+		}
+		
+		
+	// c) Compute w = s^(-1) mod q and h(m)
+	RInteger w = tS.InverseModL(tQ);
+	CleanupStack::PushL(w);
+	// Note that in order to be interoperable, compliant with the DSS, and
+	// secure, aInput must be the result of a SHA-1 hash
+	RInteger hm = RInteger::NewL(aInput);
+	CleanupStack::PushL(hm);
+
+	// d) Compute u1 = w * hm mod q and u2 = r * w mod q
+	RInteger u1 = TInteger::ModularMultiplyL(w, hm, tQ);
+	CleanupStack::PushL(u1);
+
+	RInteger u2 = TInteger::ModularMultiplyL(tR, w, tQ);
+	CleanupStack::PushL(u2);
+
+	// e) Compute v = ((g^u1 * y^u2) mod p) mod q
+	
+	const TInteger& tG=iKey->GetBigIntL(KDsaKeyParameterGUid);
+	const TInteger& tY=iKey->GetBigIntL(KDsaKeyParameterYUid);
+	const TInteger& tP=iKey->GetBigIntL(KDsaKeyParameterPUid);
+
+	RInteger temp = TInteger::ModularExponentiateL(tG, u1, tP);
+	CleanupStack::PushL(temp);
+	RInteger temp1 = TInteger::ModularExponentiateL(tY, u2, tP);
+	CleanupStack::PushL(temp1);
+	RInteger v = TInteger::ModularMultiplyL(temp, temp1, tP);
+	CleanupStack::PushL(v);
+	v %= tQ;
+
+	// f) Accept the signature if v == r
+	if(v == tR)
+		{
+		aVerificationResult = ETrue;
+		}
+
+	CleanupStack::PopAndDestroy(7, &w);
+	}
+
+
+// Methods which are not supported can be excluded from the coverage.
+#ifdef _BullseyeCoverage
+#pragma suppress_warnings on
+#pragma BullseyeCoverage off
+#pragma suppress_warnings off
+#endif
+
+void CDSAVerifierImpl::InverseSignL(HBufC8*& /*aOutput*/, const CCryptoParams& /*aSignature*/)
+	{
+	// Override in subclass
+	User::Leave(KErrNotSupported);
+	}