/*

* 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: 

* RSAFunction class implementation

*

*/

/**

 @file 

 @internalTechnology

*/

#ifndef __RSAFUNCTION_H__

#define __RSAFUNCTION_H__

#include <e32base.h>

class TInteger;

class CRSAPublicKey;

class CRSAPrivateKey;

class CRSAPrivateKeyCRT;

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 CRSAPublicKey& aPublicKey,

		const TInteger& aInput, RInteger& aOutput);

	static void DecryptL(const CRSAPrivateKey& aPrivateKey,

		const TInteger& aInput, RInteger& aOutput);

	static void SignL(const CRSAPrivateKey& aPrivateKey,

		const TInteger& aInput, RInteger& aOutput);

	static void VerifyL(const CRSAPublicKey& 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 CRSAPrivateKeyCRT& 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