1 /*

     2 * Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the License "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 * CMontgomeryStructure class implementation

    16 *

    17 */

    18 

    19 

    20 

    21 

    22 /**

    23  @file 

    24  @internalComponent

    25 */

    26  

    27 #ifndef __MONT_H__

    28 #define __MONT_H__

    29 

    30 class TInteger;

    31 class RInteger;

    32 

    33 /** A special representation of integers allowing efficient multiplication

    34  * and exponentiation under special conditions.

    35  * @internalComponent

    36  */

    37 class CMontgomeryStructure : public CBase

    38 	{

    39 public:

    40 	static CMontgomeryStructure* NewL(const TInteger& aModulus);

    41 	static CMontgomeryStructure* NewLC(const TInteger& aModulus);

    42 	~CMontgomeryStructure();

    43 	const TInteger& ReduceL(const TInteger& aInteger) const;

    44 	const TInteger& MultiplyL(const TInteger& aA, const TInteger& aB) const;

    45 	const TInteger& ExponentiateL(const TInteger& aBase, const TInteger& aExponent) const;

    46 	const TInteger& SquareL(const TInteger& aA) const;

    47 protected:

    48 	void DoMultiplyL(TInteger& aResult, const TInteger& aA, const TInteger& aB) const;

    49 	void DoSquareL(TInteger& aResult, const TInteger& aA) const;

    50 	TInteger& ConvertInL(TInteger& aInteger) const;

    51 	TInteger& ConvertOutL(TInteger& aInteger) const;

    52 	CMontgomeryStructure();

    53 private:

    54 	void ConstructL(const TInteger& aModulus);

    55 	RInteger iModulus;

    56 	RInteger iModulusInv;

    57 	RInteger iWorkspace;

    58 	mutable RInteger iResult;

    59 	};

    60 

    61 #endif // __MONT_H__