cryptoplugins/cryptospiplugins/source/softwarecrypto/rsafunction.cpp
changeset 19 cd501b96611d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cryptoplugins/cryptospiplugins/source/softwarecrypto/rsafunction.cpp	Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,138 @@
+/*
+* Copyright (c) 2003-2009 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 <bigint.h>
+#include "keys.h"
+#include <asymmetrickeys.h>
+#include <cryptospi/cryptospidef.h>
+#include <cryptospi/cryptoparams.h>
+#include "rsafunction.h"
+#include "mont.h"
+
+using namespace CryptoSpi;
+
+// Public Encrypt
+void RSAFunction::EncryptL(const CKey& aPublicKey,
+	const TInteger& aInput, RInteger& aOutput)
+	{
+	const TInteger& N = aPublicKey.GetBigIntL(KRsaKeyParameterNUid);
+	const TInteger& E = aPublicKey.GetBigIntL(KRsaKeyParameterEUid);
+	FunctionL(N, E, aInput, aOutput);
+	}
+
+// Private Decrypt
+void RSAFunction::DecryptL(const CKey& aPrivateKey, const TInteger& aInput, RInteger& aOutput)
+	{
+	if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyStandardUid)
+		{
+		const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
+		const TInteger& D = aPrivateKey.GetBigIntL(KRsaKeyParameterDUid);
+		FunctionL(N, D, aInput, aOutput);
+		}
+	else if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyCRTUid)
+		{
+		FunctionCRTL(aPrivateKey, aInput, aOutput);
+		}
+	else
+		{
+		User::Leave(KErrNotSupported);
+		}
+	}
+
+// Private Encrypt
+void RSAFunction::SignL(const CKey& aPrivateKey, const TInteger& aInput, RInteger& aOutput)
+	{
+	if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyStandardUid)
+		{
+		const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
+		const TInteger& D = aPrivateKey.GetBigIntL(KRsaKeyParameterDUid);
+		FunctionL(N, D, aInput, aOutput);
+		}
+	else if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyCRTUid)
+		{
+		FunctionCRTL(aPrivateKey, aInput, aOutput);
+		}
+	else
+	{
+		User::Leave(KErrNotSupported);
+	}
+}
+
+// Public Decrypt
+void RSAFunction::VerifyL(const CKey& aPublicKey,
+	const TInteger& aInput, RInteger& aOutput)
+	{
+	const TInteger& N = aPublicKey.GetBigIntL(KRsaKeyParameterNUid);
+	const TInteger& E = aPublicKey.GetBigIntL(KRsaKeyParameterEUid);
+	FunctionL(N, E, aInput, aOutput);
+	}
+	
+// The RSA Trapdoor Function
+void RSAFunction::FunctionL(const TInteger& aModulus, const TInteger& aExponent, 
+							 const TInteger& aBase, RInteger& aOutput)
+	{
+	IsInputValidL(aBase, aModulus);
+
+	aOutput = TInteger::ModularExponentiateL(aBase, aExponent, aModulus);
+	}
+
+// The CRT version of the RSA Trapdoor Function
+void RSAFunction::FunctionCRTL(const CKey& aPrivateKey,
+								const TInteger& aInput, RInteger& aOutput)
+	{
+	const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
+	IsInputValidL(aInput, N);
+
+	const TInteger& P = aPrivateKey.GetBigIntL(KRsaKeyParameterPUid);
+	const TInteger& Q = aPrivateKey.GetBigIntL(KRsaKeyParameterQUid);
+	const TInteger& DP = aPrivateKey.GetBigIntL(KRsaKeyParameterDPUid);
+	const TInteger& DQ = aPrivateKey.GetBigIntL(KRsaKeyParameterDQUid);
+	const TInteger& QInv = aPrivateKey.GetBigIntL(KRsaKeyParameterQInvUid);
+
+	CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(P);
+	CMontgomeryStructure* montQ = CMontgomeryStructure::NewLC(Q);
+	
+	// m1 = c^(dP) mod(p)
+	RInteger inputReduced = aInput.ModuloL(P);
+	CleanupStack::PushL(inputReduced);
+	const TInteger& m1 = montP->ExponentiateL(inputReduced, DP);
+	CleanupStack::PopAndDestroy(&inputReduced);
+
+	// m2 = c^(dQ) mod(Q)
+	inputReduced = aInput.ModuloL(Q);
+	CleanupStack::PushL(inputReduced);
+	const TInteger& m2 = montQ->ExponentiateL(inputReduced, DQ);
+	CleanupStack::PopAndDestroy(&inputReduced);
+	
+	// Calculate CRT
+	// h = (m1-m2) qInv mod(p)
+	RInteger h = m1.MinusL(m2);
+	CleanupStack::PushL(h);
+	h *= QInv;
+	h %= P;
+
+	// m = m2 + q * h
+	h *= Q;
+	h += m2;
+
+	aOutput = h;
+	CleanupStack::Pop(&h);
+
+	CleanupStack::PopAndDestroy(montQ);
+	CleanupStack::PopAndDestroy(montP);
+	}