/*

* 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: 

* ** IMPORTANT ** PublishedPartner API's in this file are published to 3rd party developers via the 

* Symbian website. Changes to these API's should be treated as PublishedAll API changes and the Security TA should be consulted.

*

*/

/**

 @file

 @publishedAll

 @released

*/

#ifndef __BIGINT_H__

#define __BIGINT_H__

#include <e32base.h>

const TUint KSignMask = 0x1L;

const TUint KHeapBasedMask = 0x2L;

const TUint KPtrMask = 0xFFFFFFFCL;

class RInteger;

/**

 * Abstract base class defining the interface for handling and manipulating big

 * integers.

 *

 * TInteger is capable of representing both negative and positive integers 

 * with an absolute value of less than 2^32^(2^32).  To create an integer 

 * look at RInteger.

 * TInteger defines an interface for the RInteger implementation - it is not

 * intended that TIntegers be copied or assigned from other TIntegers.  On EKA1

 * platforms, this is possible, but it should be avoided.

 * 

 * 

 * @see RInteger

 */

class TInteger

	{

public:

	/** @internalComponent */

	enum TRandomAttribute {EAllBitsRandom=0, ETopBitSet=1, ETop2BitsSet=2};

	IMPORT_C HBufC8* BufferLC() const;

	IMPORT_C TUint WordCount(void) const;

	IMPORT_C TUint ByteCount(void) const;

	IMPORT_C TUint BitCount(void) const;

	IMPORT_C static const TInteger& Zero(void);

	IMPORT_C static const TInteger& One(void);

	IMPORT_C static const TInteger& Two(void);

	IMPORT_C RInteger PlusL(const TInteger& aOperand) const;

	IMPORT_C RInteger MinusL(const TInteger& aOperand) const;

	IMPORT_C RInteger TimesL(const TInteger& aOperand) const;

	IMPORT_C RInteger DividedByL(const TInteger& aOperand) const;

	IMPORT_C RInteger DividedByL(TUint aOperand) const;

	IMPORT_C RInteger ModuloL(const TInteger& aOperand) const;

	IMPORT_C TUint ModuloL(TUint aOperand) const;

	IMPORT_C RInteger SquaredL(void) const;

	IMPORT_C RInteger ExponentiateL(const TInteger& aExponent) const;

	IMPORT_C static RInteger ModularMultiplyL(const TInteger& aA, const TInteger& aB,

		const TInteger& aModulus);

	IMPORT_C static RInteger ModularExponentiateL(const TInteger& aBase, 

		const TInteger& aExp, const TInteger& aMod);

	IMPORT_C RInteger GCDL(const TInteger& aOperand) const;

	IMPORT_C RInteger InverseModL(const TInteger& aMod) const;

	// These overloaded operator functions leave 

	IMPORT_C TInteger& operator += (const TInteger& aOperand);

	IMPORT_C TInteger& operator -= (const TInteger& aOperand);

	IMPORT_C TInteger& operator *= (const TInteger& aOperand);

	IMPORT_C TInteger& operator /= (const TInteger& aOperand);

	IMPORT_C TInteger& operator %= (const TInteger& aOperand);

	IMPORT_C TInteger& operator += (TInt aOperand);

	IMPORT_C TInteger& operator -= (TInt aOperand);

	IMPORT_C TInteger& operator *= (TInt aOperand);

	IMPORT_C TInteger& operator /= (TInt aOperand);

	IMPORT_C TInteger& operator %= (TInt aOperand);

	IMPORT_C TInteger& operator -- ();

	IMPORT_C TInteger& operator ++ ();

	IMPORT_C TInteger& operator <<= (TUint aBits);

	// End of leaving overloaded operator functions 

	IMPORT_C TInteger& operator >>= (TUint aBits);

	IMPORT_C TInt UnsignedCompare(const TInteger& aThat) const;

	IMPORT_C TInt SignedCompare(const TInteger& aThat) const;

	IMPORT_C TBool operator ! () const;

	inline TBool operator == (const TInteger& aInteger) const;

	inline TBool operator != (const TInteger& aInteger) const;

	inline TBool operator <= (const TInteger& aInteger) const;

	inline TBool operator >= (const TInteger& aInteger) const;

	inline TBool operator < (const TInteger& aInteger) const;

	inline TBool operator > (const TInteger& aInteger) const;

	IMPORT_C TInt SignedCompare(TInt aThat) const;

	inline TBool operator == (TInt aInteger) const;

	inline TBool operator != (TInt aInteger) const;

	inline TBool operator <= (TInt aInteger) const;

	inline TBool operator >= (TInt aInteger) const;

	inline TBool operator < (TInt aInteger) const;

	inline TBool operator > (TInt aInteger) const;

	inline TBool IsZero() const {return !*this;}

	inline TBool NotZero() const {return !IsZero();}

	inline TBool IsNegative() const {return Sign() == ENegative;}

	inline TBool NotNegative() const {return !IsNegative();}

	inline TBool IsPositive() const {return NotNegative() && NotZero();}

	inline TBool NotPositive() const {return !IsPositive();}

	inline TBool IsEven() const {return Bit(0) == EFalse;}

	inline TBool IsOdd() const {return Bit(0);}

	IMPORT_C TBool IsPrimeL(void) const;

	IMPORT_C TBool Bit(TUint aBitPos) const;

	IMPORT_C void SetBit(TUint aBitPos);

	IMPORT_C void Negate(void);

	IMPORT_C TInt ConvertToLongL(void) const;

	IMPORT_C void CopyL(const TInteger& aInteger, TBool aAllowShrink=ETrue);

	IMPORT_C void CopyL(const TInt aInteger, TBool aAllowShrink=ETrue);

	IMPORT_C void Set(const RInteger& aInteger);

	IMPORT_C HBufC8* BufferWithNoTruncationLC() const;

protected: //Interface functions to algorthims

	/** @internalComponent */

	RInteger PositiveAddL(const TInteger& aA, const TInteger& aB) const;

	/** @internalComponent */

	RInteger PositiveSubtractL(const TInteger& aA, const TInteger& aB) const;

	/** @internalComponent */

	RInteger PositiveMultiplyL(const TInteger& aA, const TInteger& aB) const;

	/** @internalComponent */

	void PositiveDivideL(RInteger& aRemainder, RInteger& aQuotient, 

		const TInteger& aDividend, const TInteger& aDivisor) const;

	/** @internalComponent */

	void DivideL(RInteger& aRemainder, RInteger& aQuotient, 

		const TInteger& aDividend, const TInteger& aDivisor) const;

	/** @internalComponent */

	void PositiveDivide(TUint& aRemainder, TInteger& aQoutient, 

		const TInteger& aDividend, TUint aDivisor) const;

	/** @internalComponent */

	void DivideL(TUint& aRemainder, RInteger& aQoutient, 

		const TInteger& aDividend, TUint aDivisor) const;

	/** @internalComponent */

	TUint Modulo(const TInteger& aDividend, TUint aDivisor) const;

protected: //Utility functions

	/** @internalComponent */

	TInt ConvertToLong(void) const;

	inline TUint ConvertToUnsignedLong(void) const {return Ptr()[0];}

	/** @internalComponent */

	TBool IsConvertableToLong(void) const;

	/** @internalComponent */

	void RandomizeL(TUint aBits, TRandomAttribute aAttr);

	/** @internalComponent */

	void RandomizeL(const TInteger& aMin, const TInteger& aMax);

	/** @internalComponent */

	void PrimeRandomizeL(TUint aBits, TRandomAttribute aAttr);

	/** @internalComponent */

	TBool SmallPrimeRandomizeL(void);

protected: //Memory Handling

	/** @internalComponent */

	void CreateNewL(TUint aNewSize);

	/** @internalComponent */

	void CleanNewL(TUint aNewSize);

	/** @internalComponent */

	void CleanGrowL(TUint aNewSize);

	/** @internalComponent */

	void CleanResizeL(TUint aNewSize);

protected: //Construction functions

	IMPORT_C TInteger(void);

	/** @internalComponent */

	void Construct(const TDesC8& aValue);

	/** @internalComponent */

	void Construct(const TInteger& aInteger);

	/** @internalComponent */

	void Construct(TInt aInteger);

	/** @internalComponent */

	void Construct(TUint aInteger);

protected: //Construction functions for stack based integers

	/** @internalComponent */

	void ConstructStack(TUint aWords, TUint aInteger);

	/** @internalComponent */

	void ConstructStack(TUint aWords, const TInteger& aInteger);

protected: //Member data

	enum TSign {EPositive=0, ENegative=1};

	TUint iSize;

	TUint iPtr;

protected: //Hackish functions

	/* Memory Layout

	 * Word 0: Size -- Must be power of 2 (algorithms assume this)

	 * Word 1: Pointer to storage location plus 2 flag bits in lsb

	 * Word 1 (bit 0): Sign of the integer (+ve == 0, -ve == 1)

	 * Word 1 (bit 1): Heap based flag bit (stack== 0, heap==1)

	 */

	inline TSign Sign(void) const {return (TSign)(iPtr&KSignMask);}

	inline TUint Size(void) const {return iSize;}

	inline void SetSize(TUint aSize) {iSize = aSize;}

	inline TUint* const Ptr(void) const {return (TUint*)(iPtr&KPtrMask);}

	inline TBool IsStackBased(void) const {return !IsHeapBased();}

	inline TBool IsHeapBased(void) const {return iPtr&KHeapBasedMask;}

	inline void SetPtr(TUint* aPtr) {iPtr &= ~KPtrMask; iPtr |= (TUint)aPtr;}

	inline void SetHeapBased(void) {iPtr |= KHeapBasedMask;}

	inline void SetStackBased(void) {iPtr &= ~KHeapBasedMask;}

	inline void SetSign(TSign aSign) {iPtr &= ~KSignMask; iPtr |= (TUint)aSign;}

private:

	// disable default copy constructor and assignment operator

	TInteger(const TInteger& aInteger);

	TInteger& operator=(const TInteger& aInteger);

	friend class CMontgomeryStructure;

	friend class RInteger; //in order to have access to Size() for an argument

	};

// Inline methods for TInteger

inline TBool TInteger::operator == (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) == 0;

	}

inline TBool TInteger::operator != (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) != 0;

	}

inline TBool TInteger::operator <= (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) <= 0;

	}

inline TBool TInteger::operator >= (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) >= 0;

	}

inline TBool TInteger::operator < (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) < 0;

	}

TBool TInteger::operator > (const TInteger& aInteger) const

	{

	return SignedCompare(aInteger) > 0;

	}

inline TBool TInteger::operator == (TInt aInteger) const

	{

	return SignedCompare(aInteger) == 0;

	}

inline TBool TInteger::operator != (TInt aInteger) const

	{

	return SignedCompare(aInteger) != 0;

	}

inline TBool TInteger::operator <= (TInt aInteger) const

	{

	return SignedCompare(aInteger) <= 0;

	}

inline TBool TInteger::operator >= (TInt aInteger) const

	{

	return SignedCompare(aInteger) >= 0;

	}

inline TBool TInteger::operator < (TInt aInteger) const

	{

	return SignedCompare(aInteger) < 0;

	}

inline TBool TInteger::operator > (TInt aInteger) const

	{

	return SignedCompare(aInteger) > 0;

	}

/** 

 * A TInteger derived class allowing the construction of variable length big integers.

 * See the Cryptography API guide for further information.

 *

 *

 * @see TInteger

 */

class RInteger : public TInteger

	{

public:

	IMPORT_C static RInteger NewL(void);

	IMPORT_C static RInteger NewL(const TDesC8& aValue);

	IMPORT_C static RInteger NewL(const TInteger& aInteger);

	IMPORT_C static RInteger NewL(TInt aInteger);

	IMPORT_C static RInteger NewL(TUint aInteger);

	IMPORT_C static RInteger NewEmptyL(TUint aNumWords);

	IMPORT_C static RInteger NewRandomL(TUint aBits, 

		TRandomAttribute aAttr=EAllBitsRandom);

	IMPORT_C static RInteger NewRandomL(const TInteger& aMin,

		const TInteger& aMax);

	IMPORT_C static RInteger NewPrimeL(TUint aBits, 

		TRandomAttribute aAttr=EAllBitsRandom);

	IMPORT_C RInteger(void);

	IMPORT_C RInteger(const RInteger& aInteger);

	IMPORT_C RInteger& operator=(const RInteger& aInteger);

	IMPORT_C operator TCleanupItem();

	IMPORT_C static void CallClose(TAny* aPtr);

	IMPORT_C void Close(void);

	};

#endif // __BIGINT_H__