sl@0: /*
sl@0: * Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #include <bigint.h>
sl@0: #include "keys.h"
sl@0: #include <asymmetrickeys.h>
sl@0: #include <cryptospi/cryptospidef.h>
sl@0: #include <cryptospi/cryptoparams.h>
sl@0: #include "rsafunction.h"
sl@0: #include "mont.h"
sl@0: 
sl@0: using namespace CryptoSpi;
sl@0: 
sl@0: // Public Encrypt
sl@0: void RSAFunction::EncryptL(const CKey& aPublicKey,
sl@0: 	const TInteger& aInput, RInteger& aOutput)
sl@0: 	{
sl@0: 	const TInteger& N = aPublicKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	const TInteger& E = aPublicKey.GetBigIntL(KRsaKeyParameterEUid);
sl@0: 	FunctionL(N, E, aInput, aOutput);
sl@0: 	}
sl@0: 
sl@0: // Private Decrypt
sl@0: void RSAFunction::DecryptL(const CKey& aPrivateKey, const TInteger& aInput, RInteger& aOutput)
sl@0: 	{
sl@0: 	if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyStandardUid)
sl@0: 		{
sl@0: 		const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 		const TInteger& D = aPrivateKey.GetBigIntL(KRsaKeyParameterDUid);
sl@0: 		FunctionL(N, D, aInput, aOutput);
sl@0: 		}
sl@0: 	else if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyCRTUid)
sl@0: 		{
sl@0: 		FunctionCRTL(aPrivateKey, aInput, aOutput);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		User::Leave(KErrNotSupported);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: // Private Encrypt
sl@0: void RSAFunction::SignL(const CKey& aPrivateKey, const TInteger& aInput, RInteger& aOutput)
sl@0: 	{
sl@0: 	if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyStandardUid)
sl@0: 		{
sl@0: 		const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 		const TInteger& D = aPrivateKey.GetBigIntL(KRsaKeyParameterDUid);
sl@0: 		FunctionL(N, D, aInput, aOutput);
sl@0: 		}
sl@0: 	else if (aPrivateKey.KeyProperty().iKeyType == KRsaPrivateKeyCRTUid)
sl@0: 		{
sl@0: 		FunctionCRTL(aPrivateKey, aInput, aOutput);
sl@0: 		}
sl@0: 	else
sl@0: 	{
sl@0: 		User::Leave(KErrNotSupported);
sl@0: 	}
sl@0: }
sl@0: 
sl@0: // Public Decrypt
sl@0: void RSAFunction::VerifyL(const CKey& aPublicKey,
sl@0: 	const TInteger& aInput, RInteger& aOutput)
sl@0: 	{
sl@0: 	const TInteger& N = aPublicKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	const TInteger& E = aPublicKey.GetBigIntL(KRsaKeyParameterEUid);
sl@0: 	FunctionL(N, E, aInput, aOutput);
sl@0: 	}
sl@0: 	
sl@0: // The RSA Trapdoor Function
sl@0: void RSAFunction::FunctionL(const TInteger& aModulus, const TInteger& aExponent, 
sl@0: 							 const TInteger& aBase, RInteger& aOutput)
sl@0: 	{
sl@0: 	IsInputValidL(aBase, aModulus);
sl@0: 
sl@0: 	aOutput = TInteger::ModularExponentiateL(aBase, aExponent, aModulus);
sl@0: 	}
sl@0: 
sl@0: // The CRT version of the RSA Trapdoor Function
sl@0: void RSAFunction::FunctionCRTL(const CKey& aPrivateKey,
sl@0: 								const TInteger& aInput, RInteger& aOutput)
sl@0: 	{
sl@0: 	const TInteger& N = aPrivateKey.GetBigIntL(KRsaKeyParameterNUid);
sl@0: 	IsInputValidL(aInput, N);
sl@0: 
sl@0: 	const TInteger& P = aPrivateKey.GetBigIntL(KRsaKeyParameterPUid);
sl@0: 	const TInteger& Q = aPrivateKey.GetBigIntL(KRsaKeyParameterQUid);
sl@0: 	const TInteger& DP = aPrivateKey.GetBigIntL(KRsaKeyParameterDPUid);
sl@0: 	const TInteger& DQ = aPrivateKey.GetBigIntL(KRsaKeyParameterDQUid);
sl@0: 	const TInteger& QInv = aPrivateKey.GetBigIntL(KRsaKeyParameterQInvUid);
sl@0: 
sl@0: 	CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(P);
sl@0: 	CMontgomeryStructure* montQ = CMontgomeryStructure::NewLC(Q);
sl@0: 	
sl@0: 	// m1 = c^(dP) mod(p)
sl@0: 	RInteger inputReduced = aInput.ModuloL(P);
sl@0: 	CleanupStack::PushL(inputReduced);
sl@0: 	const TInteger& m1 = montP->ExponentiateL(inputReduced, DP);
sl@0: 	CleanupStack::PopAndDestroy(&inputReduced);
sl@0: 
sl@0: 	// m2 = c^(dQ) mod(Q)
sl@0: 	inputReduced = aInput.ModuloL(Q);
sl@0: 	CleanupStack::PushL(inputReduced);
sl@0: 	const TInteger& m2 = montQ->ExponentiateL(inputReduced, DQ);
sl@0: 	CleanupStack::PopAndDestroy(&inputReduced);
sl@0: 	
sl@0: 	// Calculate CRT
sl@0: 	// h = (m1-m2) qInv mod(p)
sl@0: 	RInteger h = m1.MinusL(m2);
sl@0: 	CleanupStack::PushL(h);
sl@0: 	h *= QInv;
sl@0: 	h %= P;
sl@0: 
sl@0: 	// m = m2 + q * h
sl@0: 	h *= Q;
sl@0: 	h += m2;
sl@0: 
sl@0: 	aOutput = h;
sl@0: 	CleanupStack::Pop(&h);
sl@0: 
sl@0: 	CleanupStack::PopAndDestroy(montQ);
sl@0: 	CleanupStack::PopAndDestroy(montP);
sl@0: 	}