--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcrypto/source/asymmetric/rsafunction.cpp	Wed Jul 08 11:25:26 2009 +0100
@@ -0,0 +1,130 @@
+/*
+* 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 <asymmetrickeys.h>
+#include "rsafunction.h"
+#include "../bigint/mont.h"
+
+//Public Encrypt
+void RSAFunction::EncryptL(const CRSAPublicKey& aPublicKey, 
+	const TInteger& aInput, RInteger& aOutput)
+	{
+	FunctionL(aPublicKey.N(), aPublicKey.E(), aInput, aOutput);
+	}
+
+//Private Decrypt
+void RSAFunction::DecryptL(const CRSAPrivateKey& aPrivateKey, 
+							const TInteger& aInput, RInteger& aOutput)
+	{
+	if (aPrivateKey.PrivateKeyType()==EStandard)
+		{
+		const CRSAPrivateKeyStandard* stdKey = 
+			static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey);
+		FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput);
+		}
+	else if (aPrivateKey.PrivateKeyType()==EStandardCRT)
+		{
+		FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, 
+			aOutput);
+		}
+	else
+		{
+		User::Leave(KErrNotSupported);
+		}
+	}
+
+//Private Encrypt
+void RSAFunction::SignL(const CRSAPrivateKey& aPrivateKey, 
+	const TInteger& aInput, RInteger& aOutput)
+	{
+	if (aPrivateKey.PrivateKeyType()==EStandard)
+		{
+		const CRSAPrivateKeyStandard* stdKey = 
+			static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey);
+		FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput);
+		}
+	else if (aPrivateKey.PrivateKeyType()==EStandardCRT)
+		{
+		FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, 
+			aOutput);
+		}
+	else
+	{
+		User::Leave(KErrNotSupported);
+	}
+}
+
+//Public Decrypt
+void RSAFunction::VerifyL(const CRSAPublicKey& aPublicKey,
+	const TInteger& aInput, RInteger& aOutput)
+	{
+	FunctionL(aPublicKey.N(), aPublicKey.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 CRSAPrivateKeyCRT& aPrivateKey,
+								const TInteger& aInput, RInteger& aOutput)
+	{
+	IsInputValidL(aInput, aPrivateKey.N());
+
+	CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(aPrivateKey.P());
+	CMontgomeryStructure* montQ = CMontgomeryStructure::NewLC(aPrivateKey.Q());
+	
+	const TInteger& p = aPrivateKey.P();
+	const TInteger& q = aPrivateKey.Q();
+	const TInteger& u = aPrivateKey.QInv();
+
+	//m1 = c^(dP) mod(p)
+	RInteger inputReduced = aInput.ModuloL(aPrivateKey.P());
+	CleanupStack::PushL(inputReduced);
+	const TInteger& m1 = montP->ExponentiateL(inputReduced, aPrivateKey.DP());
+	CleanupStack::PopAndDestroy(&inputReduced);
+
+	//m2 = c^(dQ) mod(Q)
+	inputReduced = aInput.ModuloL(aPrivateKey.Q());
+	CleanupStack::PushL(inputReduced);
+	const TInteger& m2 = montQ->ExponentiateL(inputReduced, aPrivateKey.DQ());
+	CleanupStack::PopAndDestroy(&inputReduced);
+	
+	//Calculate CRT
+	//h = (m1-m2) qInv mod(p)
+	RInteger h = m1.MinusL(m2);
+	CleanupStack::PushL(h);
+	h *= u;
+	h %= p; 
+
+	//m = m2 + q * h	
+	h *= q;
+	h += m2;
+
+	aOutput = h;
+	CleanupStack::Pop(&h);
+
+	CleanupStack::PopAndDestroy(montQ);
+	CleanupStack::PopAndDestroy(montP);
+	}