--- /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);
+ }