/*

 * 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: 

 *

 */

 /**

  @file

  @internalComponent

  @released

 */

 #ifndef __RSAFUNCTION_H__

 #define __RSAFUNCTION_H__

 #include <e32base.h>

 #include "keys.h"

 using namespace CryptoSpi;

 class TInteger;

 class RSAFunction

 	{

 public:

 	static inline TBool IsInputValid(const TInteger& aInput, 

 		const TInteger& aModulus);

 	static inline void IsInputValidL(const TInteger& aInput, 

 		const TInteger& aModulus);

 	static void EncryptL(const CKey& aPublicKey,

 		const TInteger& aInput, RInteger& aOutput);

 	static void DecryptL(const CKey& aPrivateKey,

 		const TInteger& aInput, RInteger& aOutput);

 	static void SignL(const CKey& aPrivateKey,

 		const TInteger& aInput, RInteger& aOutput);

 	static void VerifyL(const CKey& aPublicKey,

 		const TInteger& aInput, RInteger& aOutput);

 private:

 	static void FunctionL(const TInteger& aModulus, const TInteger& aExponent,

 		const TInteger& aBase, RInteger& aOutput);

 	static void FunctionCRTL(const CKey& aPrivateKey,

 		const TInteger& aInput, RInteger& aOutput);

 private:

 	RSAFunction(void);

 	};

 /** Computes whether a given message representative is within the valid bounds

  * for a given modulus, i.e. whether the message is representative within [0,n-1].

  * @param aInput The message representative.

  * @param aModulus The modulus.

  * @return TBool representing whether or not the message representative is

  * valid.

  */

 TBool RSAFunction::IsInputValid(const TInteger& aInput, 

 	const TInteger& aModulus)

 	{

 	//See HAC 8.3 1.b

 	//Message (input) must be in the interval [0,n-1] (inclusive)

 	if( aInput.IsNegative() || aInput >= aModulus )

 		return EFalse;

 	else

 		return ETrue;

 	}

 void RSAFunction::IsInputValidL(const TInteger& aInput,

 	const TInteger& aModulus)

 	{

 	if(!IsInputValid(aInput, aModulus))

 		User::Leave(KErrArgument);

 	}

 #endif