sl@0: /*
sl@0: * Copyright (c) 2003-2010 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 <random.h>
sl@0: #include <bigint.h>
sl@0: #include <e32std.h>
sl@0: #include <euserext.h>
sl@0: #include <securityerr.h>
sl@0: #include "words.h"
sl@0: #include "algorithms.h"
sl@0: #include "windowslider.h"
sl@0: #include "stackinteger.h"
sl@0: #include "mont.h"
sl@0: 
sl@0: 
sl@0: /**
sl@0: * Creates a new buffer containing the big-endian binary representation of this
sl@0: * integer.
sl@0: *
sl@0: * Note that it does not support the exporting of negative integers.
sl@0: *
sl@0: * @return	The new buffer.
sl@0: * 
sl@0: * @leave KErrNegativeExportNotSupported	If this instance is a negative integer.
sl@0: *
sl@0: */
sl@0: EXPORT_C HBufC8* TInteger::BufferLC() const
sl@0: 	{
sl@0: 	if(IsNegative())
sl@0: 		{
sl@0: 		User::Leave(KErrNegativeExportNotSupported);
sl@0: 		}
sl@0: 	TUint bytes = ByteCount();
sl@0: 	HBufC8* buf = HBufC8::NewMaxLC(bytes);
sl@0: 	TUint8* bufPtr = (TUint8*)(buf->Ptr());
sl@0: 	TUint8* regPtr = (TUint8*)Ptr();
sl@0: 
sl@0: 	// we internally store the number little endian, as a string we want it big
sl@0: 	// endian
sl@0: 	for(TUint i=0,j=bytes-1; i<bytes; )
sl@0: 		{
sl@0: 		bufPtr[i++] = regPtr[j--];
sl@0: 		}
sl@0: 	return buf;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C HBufC8* TInteger::BufferWithNoTruncationLC() const
sl@0:  	{
sl@0:  	if(IsNegative())
sl@0:  		{
sl@0:  		User::Leave(KErrNegativeExportNotSupported);
sl@0:  		}
sl@0:  	
sl@0:  	TUint wordCount = Size();
sl@0:  	TUint bytes = (wordCount)*WORD_SIZE;
sl@0:      
sl@0:   	HBufC8* buf = HBufC8::NewMaxLC(bytes);
sl@0:  	TUint8* bufPtr = (TUint8*)(buf->Ptr());
sl@0: 	TUint8* regPtr = (TUint8*)Ptr();
sl@0: 	for(TUint i=0,j=bytes-1; i<bytes; )
sl@0:  		{
sl@0:  		bufPtr[i++] = regPtr[j--];
sl@0:  		}
sl@0:   
sl@0: 	return buf;
sl@0: 	}
sl@0: 
sl@0: /** 
sl@0: * Gets the number of words required to represent this RInteger.
sl@0: * 
sl@0: * @return	The size of the integer in words.
sl@0: *
sl@0: */
sl@0: EXPORT_C TUint TInteger::WordCount() const
sl@0: 	{
sl@0: 	return CountWords(Ptr(), Size());
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: * Gets the number of bytes required to represent this RInteger.
sl@0: * 
sl@0: * @return	The size of the integer in bytes.
sl@0: * 
sl@0: */
sl@0: EXPORT_C TUint TInteger::ByteCount() const
sl@0: 	{
sl@0: 	TUint wordCount = WordCount();
sl@0: 	if(wordCount)
sl@0: 		{
sl@0: 		return (wordCount-1)*WORD_SIZE + BytePrecision((Ptr())[wordCount-1]);
sl@0: 		}
sl@0: 	else 
sl@0: 		{
sl@0: 		return 0;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: /** 
sl@0: * Get the number of bits required to represent this RInteger.
sl@0: * 
sl@0: * @return	The size of the integer in bits.
sl@0: * 
sl@0: */
sl@0: EXPORT_C TUint TInteger::BitCount() const
sl@0: 	{
sl@0: 	TUint wordCount = WordCount();
sl@0: 	if(wordCount)
sl@0: 		{
sl@0: 		return (wordCount-1)*WORD_BITS + BitPrecision(Ptr()[wordCount-1]);
sl@0: 		}
sl@0: 	else 
sl@0: 		{
sl@0: 		return 0;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: 
sl@0: //These 3 declarations instantiate a constant 0, 1, 2 for ease of use and
sl@0: //quick construction elsewhere in the code.  Note that the functions
sl@0: //returning references to this static data return const references as you can't
sl@0: //modify the ROM ;)
sl@0: //word 0: Size of storage in words
sl@0: //word 1: Pointer to storage
sl@0: //word 2: LSW of storage
sl@0: //word 3: MSW of storage
sl@0: //Note that the flag bits in word 1 (Ptr()) are zero in the case of a positive
sl@0: //stack based integer (SignBit == 0, IsHeapBasedBit == 0)
sl@0: const TUint KBigintZero[4] = {2, (TUint)(KBigintZero+2), 0, 0};
sl@0: const TUint KBigintOne[4] = {2, (TUint)(KBigintOne+2), 1, 0};
sl@0: const TUint KBigintTwo[4] = {2, (TUint)(KBigintTwo+2), 2, 0};
sl@0: 
sl@0: /** 
sl@0:  * Gets the TInteger that represents zero
sl@0:  *
sl@0:  * @return	The TInteger representing zero
sl@0:  */
sl@0: EXPORT_C const TInteger& TInteger::Zero(void)
sl@0: 	{
sl@0: 	return *reinterpret_cast<const TStackInteger64*>(KBigintZero);
sl@0: 	}
sl@0: 
sl@0: /** 
sl@0:  * Gets the TInteger that represents one
sl@0:  *
sl@0:  * @return	The TInteger representing one
sl@0:  */
sl@0: EXPORT_C const TInteger& TInteger::One(void)
sl@0: 	{
sl@0: 	return *reinterpret_cast<const TStackInteger64*>(KBigintOne);
sl@0: 	}
sl@0: 	
sl@0: /** 
sl@0:  * Gets the TInteger that represents two
sl@0:  *
sl@0:  * @return	The TInteger representing two
sl@0:  */
sl@0: EXPORT_C const TInteger& TInteger::Two(void)
sl@0: 	{
sl@0: 	return *reinterpret_cast<const TStackInteger64*>(KBigintTwo);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::PlusL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	RInteger sum;
sl@0:     if (NotNegative())
sl@0: 		{
sl@0:         if (aOperand.NotNegative())
sl@0:             sum = PositiveAddL(*this, aOperand);
sl@0:         else
sl@0:             sum = PositiveSubtractL(*this, aOperand);
sl@0: 		}
sl@0:     else
sl@0: 		{
sl@0:         if (aOperand.NotNegative())
sl@0:             sum = PositiveSubtractL(aOperand, *this);
sl@0:         else
sl@0: 			{
sl@0:             sum = PositiveAddL(*this, aOperand);
sl@0: 			sum.SetSign(TInteger::ENegative);
sl@0: 			}
sl@0: 		}
sl@0: 	return sum;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::MinusL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	RInteger diff;
sl@0:     if (NotNegative())
sl@0: 		{
sl@0:         if (aOperand.NotNegative())
sl@0:             diff = PositiveSubtractL(*this, aOperand);
sl@0:         else
sl@0:             diff = PositiveAddL(*this, aOperand);
sl@0: 		}
sl@0:     else
sl@0: 		{
sl@0:         if (aOperand.NotNegative())
sl@0: 			{
sl@0:             diff = PositiveAddL(*this, aOperand);
sl@0: 			diff.SetSign(TInteger::ENegative);
sl@0: 			}
sl@0:         else
sl@0:             diff = PositiveSubtractL(aOperand, *this);
sl@0: 		}
sl@0: 	return diff;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::TimesL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	RInteger product = PositiveMultiplyL(*this, aOperand);
sl@0: 
sl@0: 	if (NotNegative() != aOperand.NotNegative())
sl@0: 		{
sl@0: 		product.Negate();
sl@0: 		}
sl@0: 	return product;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::DividedByL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	RInteger quotient;
sl@0: 	RInteger remainder;
sl@0: 	DivideL(remainder, quotient, *this, aOperand);
sl@0: 	remainder.Close();
sl@0: 	return quotient;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::ModuloL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	RInteger remainder;
sl@0: 	RInteger quotient;
sl@0: 	DivideL(remainder, quotient, *this, aOperand);
sl@0: 	quotient.Close();
sl@0: 	return remainder;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TUint TInteger::ModuloL(TUint aOperand) const
sl@0: 	{
sl@0: 	if(!aOperand)
sl@0: 		{
sl@0: 		User::Leave(KErrDivideByZero);
sl@0: 		}
sl@0: 	return Modulo(*this, aOperand);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::ModularMultiplyL(const TInteger& aA, const TInteger& aB,
sl@0: 	const TInteger& aMod) 
sl@0: 	{
sl@0: 	RInteger product = aA.TimesL(aB);
sl@0: 	CleanupStack::PushL(product);
sl@0: 	RInteger reduced = product.ModuloL(aMod);
sl@0: 	CleanupStack::PopAndDestroy(&product); 
sl@0: 	return reduced;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::ModularExponentiateL(const TInteger& aBase, 
sl@0: 	const TInteger& aExp, const TInteger& aMod) 
sl@0: 	{
sl@0: 	CMontgomeryStructure* mont = CMontgomeryStructure::NewLC(aMod);
sl@0: 	RInteger result = RInteger::NewL(mont->ExponentiateL(aBase, aExp));
sl@0: 	CleanupStack::PopAndDestroy(mont);
sl@0: 	return result;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::GCDL(const TInteger& aOperand) const
sl@0: 	{
sl@0: 	//Binary GCD algorithm -- see HAC 14.4.1
sl@0: 	//with a slight variation -- our g counts shifts rather than actually
sl@0: 	//shifting.  We then do one shift at the end.
sl@0: 	assert(NotNegative());
sl@0: 	assert(aOperand.NotNegative());
sl@0: 
sl@0: 	RInteger x = RInteger::NewL(*this);
sl@0: 	CleanupStack::PushL(x);
sl@0: 	RInteger y = RInteger::NewL(aOperand);
sl@0: 	CleanupStack::PushL(y);
sl@0: 
sl@0: 	// 1 Ensure x >= y
sl@0: 	if( x < y )
sl@0: 		{
sl@0: 		TClassSwap(x, y);
sl@0: 		}
sl@0: 
sl@0: 	TUint g = 0;
sl@0: 	// 2 while x and y even x <- x/2, y <- y/2
sl@0: 	while( x.IsEven() && y.IsEven() )
sl@0: 		{
sl@0: 		x >>= 1;
sl@0: 		y >>= 1;
sl@0: 		++g;
sl@0: 		}
sl@0: 	// 3 while x != 0
sl@0: 	while( x.NotZero() )
sl@0: 		{
sl@0: 		// 3.1 while x even x <- x/2
sl@0: 		while( x.IsEven() )
sl@0: 			{
sl@0: 			x >>= 1;
sl@0: 			}
sl@0: 		// 3.2 while y even y <- y/2
sl@0: 		while( y.IsEven() )
sl@0: 			{
sl@0: 			y >>= 1;
sl@0: 			}
sl@0: 		// 3.3 t <- abs(x-y)/2
sl@0: 		RInteger t = x.MinusL(y);
sl@0: 		t >>= 1;
sl@0: 		t.SetSign(TInteger::EPositive);
sl@0: 
sl@0: 		// 3.4 If x>=y then x <- t else y <- t
sl@0: 		if( x >= y )
sl@0: 			{
sl@0: 			x.Set(t);
sl@0: 			}
sl@0: 		else 
sl@0: 			{
sl@0: 			y.Set(t);
sl@0: 			}
sl@0: 		}
sl@0: 	
sl@0: 	// 4 Return (g*y) (equiv to y<<=g as our g was counting shifts not actually
sl@0: 	//shifting)
sl@0: 	y <<= g;
sl@0: 	CleanupStack::Pop(&y);
sl@0: 	CleanupStack::PopAndDestroy(&x); 
sl@0: 	return y;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::InverseModL(const TInteger& aMod) const
sl@0: 	{
sl@0: 	assert(aMod.NotNegative());
sl@0: 
sl@0: 	RInteger result;
sl@0: 	if(IsNegative() || *this>=aMod)
sl@0: 		{
sl@0: 		RInteger temp = ModuloL(aMod);
sl@0: 		CleanupClosePushL(temp);
sl@0: 		result = temp.InverseModL(aMod);
sl@0: 		CleanupStack::PopAndDestroy(&temp);
sl@0: 		return result;
sl@0: 		}
sl@0: 
sl@0: 	if(aMod.IsEven())
sl@0: 		{
sl@0: 		if( !aMod || IsEven() )
sl@0: 			{
sl@0: 			return RInteger::NewL(Zero());
sl@0: 			}
sl@0: 		if( *this == One() )
sl@0: 			{
sl@0: 			return RInteger::NewL(One());
sl@0: 			}
sl@0: 		RInteger u = aMod.InverseModL(*this); 
sl@0: 		CleanupClosePushL(u);
sl@0: 		if(!u)
sl@0: 			{
sl@0: 			result = RInteger::NewL(Zero());
sl@0: 			}
sl@0: 		else 
sl@0: 			{
sl@0: 			//calculates (aMod*(*this-u)+1)/(*this) 
sl@0: 			result = MinusL(u);
sl@0: 			CleanupClosePushL(result);
sl@0: 			result *= aMod;
sl@0: 			++result;
sl@0: 			result /= *this;
sl@0: 			CleanupStack::Pop(&result); 
sl@0: 			}
sl@0: 		CleanupStack::PopAndDestroy(&u);
sl@0: 		return result;
sl@0: 		}
sl@0: 
sl@0: 	result = RInteger::NewEmptyL(aMod.Size());
sl@0: 	CleanupClosePushL(result);
sl@0: 	RInteger workspace = RInteger::NewEmptyL(aMod.Size() * 4);
sl@0: 	TUint k = AlmostInverse(result.Ptr(), workspace.Ptr(), Ptr(), Size(),
sl@0: 		aMod.Ptr(), aMod.Size());
sl@0: 	DivideByPower2Mod(result.Ptr(), result.Ptr(), k, aMod.Ptr(), aMod.Size());
sl@0: 	workspace.Close();
sl@0: 	CleanupStack::Pop(&result);
sl@0: 
sl@0: 	return result;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator+=(const TInteger& aOperand)
sl@0: 	{
sl@0: 	this->Set(PlusL(aOperand));
sl@0:     return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator-=(const TInteger& aOperand)
sl@0: 	{
sl@0: 	this->Set(MinusL(aOperand));
sl@0:     return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator*=(const TInteger& aOperand)
sl@0: 	{
sl@0: 	this->Set(TimesL(aOperand));
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator/=(const TInteger& aOperand)
sl@0: 	{
sl@0: 	this->Set(DividedByL(aOperand));
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator%=(const TInteger& aOperand)
sl@0: 	{
sl@0: 	this->Set(ModuloL(aOperand));
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator+=(TInt aOperand)
sl@0: 	{
sl@0: 	TStackInteger64 operand(aOperand);
sl@0: 	*this += operand;
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator-=(TInt aOperand)
sl@0: 	{
sl@0: 	TStackInteger64 operand(aOperand);
sl@0: 	*this -= operand;
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator*=(TInt aOperand)
sl@0: 	{
sl@0: 	TStackInteger64 operand(aOperand);
sl@0: 	*this *= operand;
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator--()
sl@0: 	{
sl@0:     if (IsNegative())
sl@0: 		{
sl@0:         if (Increment(Ptr(), Size()))
sl@0: 			{
sl@0:             CleanGrowL(2*Size());
sl@0:             (Ptr())[Size()/2]=1;
sl@0: 			}
sl@0: 		}
sl@0:     else
sl@0: 		{
sl@0:         if (Decrement(Ptr(), Size()))
sl@0: 			{
sl@0: 			this->CopyL(-1);
sl@0: 			}
sl@0: 		}
sl@0:     return *this;	
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator++()
sl@0: 	{
sl@0: 	if(NotNegative())
sl@0: 		{
sl@0: 		if(Increment(Ptr(), Size()))
sl@0: 			{
sl@0: 			CleanGrowL(2*Size());
sl@0: 			(Ptr())[Size()/2]=1;
sl@0: 			}
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		DecrementNoCarry(Ptr(), Size());
sl@0: 		if(WordCount()==0)
sl@0: 			{
sl@0: 			this->CopyL(Zero());
sl@0: 			}
sl@0: 		}
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator <<=(TUint aBits)
sl@0: 	{
sl@0: 	const TUint wordCount = WordCount();
sl@0: 	const TUint shiftWords = aBits / WORD_BITS;
sl@0: 	const TUint shiftBits = aBits % WORD_BITS;
sl@0: 
sl@0: 	CleanGrowL(wordCount+BitsToWords(aBits));
sl@0: 	ShiftWordsLeftByWords(Ptr(), wordCount + shiftWords, shiftWords);
sl@0: 	ShiftWordsLeftByBits(Ptr()+shiftWords, wordCount + BitsToWords(shiftBits), 
sl@0: 		shiftBits);
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator >>=(TUint aBits)
sl@0: 	{
sl@0: 	const TUint wordCount = WordCount();
sl@0: 	const TUint shiftWords = aBits / WORD_BITS;
sl@0: 	const TUint shiftBits = aBits % WORD_BITS;
sl@0: 
sl@0: 	ShiftWordsRightByWords(Ptr(), wordCount, shiftWords);
sl@0: 	if(wordCount > shiftWords)
sl@0: 		{
sl@0: 		ShiftWordsRightByBits(Ptr(), wordCount - shiftWords, shiftBits);
sl@0: 		}
sl@0: 	if(IsNegative() && WordCount()==0) // avoid negative 0
sl@0: 		{
sl@0: 		SetSign(EPositive);
sl@0: 		}
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TInteger::UnsignedCompare(const TInteger& aThat) const
sl@0: 	{
sl@0: 	TUint size = WordCount();
sl@0: 	TUint thatSize = aThat.WordCount();
sl@0: 
sl@0: 	if( size == thatSize )
sl@0: 		return Compare(Ptr(), aThat.Ptr(), size);
sl@0: 	else
sl@0: 		return size > thatSize ? 1 : -1;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TInteger::SignedCompare(const TInteger& aThat) const
sl@0: 	{
sl@0:     if (NotNegative())
sl@0: 		{
sl@0:         if (aThat.NotNegative())
sl@0:             return UnsignedCompare(aThat);
sl@0:         else
sl@0:             return 1;
sl@0: 		}
sl@0:     else
sl@0: 		{
sl@0:         if (aThat.NotNegative())
sl@0:             return -1;
sl@0:         else
sl@0:             return -UnsignedCompare(aThat);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TBool TInteger::operator!() const
sl@0: 	{
sl@0: 	//Ptr()[0] is just a quick way of weeding out non-zero numbers without
sl@0: 	//doing a full WordCount() == 0.  Very good odds that a non-zero number
sl@0: 	//will have a bit set in the least significant word
sl@0: 	return IsNegative() ? EFalse : (Ptr()[0]==0 && WordCount()==0);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TInteger::SignedCompare(TInt aInteger) const
sl@0: 	{
sl@0: 	TStackInteger64 temp(aInteger);
sl@0: 	return SignedCompare(temp);
sl@0: 	}
sl@0: 
sl@0: /* TBool IsPrimeL(void) const 
sl@0:  * and all primality related functions are implemented in primes.cpp */
sl@0: 
sl@0: EXPORT_C TBool TInteger::Bit(TUint aBitPos) const
sl@0: 	{
sl@0: 	if( aBitPos/WORD_BITS >= Size() )
sl@0: 		{
sl@0: 		return 0;
sl@0: 		}
sl@0: 	else 
sl@0: 		{
sl@0: 		return (((Ptr())[aBitPos/WORD_BITS] >> (aBitPos % WORD_BITS)) & 1);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TInteger::SetBit(TUint aBitPos) 
sl@0: 	{
sl@0: 	if( aBitPos/WORD_BITS < Size() )
sl@0: 		{
sl@0: 		ArraySetBit(Ptr(), aBitPos);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TInteger::Negate() 
sl@0: 	{
sl@0: 	if(!!(*this)) //don't flip sign if *this==0
sl@0: 		{
sl@0: 		SetSign(TSign((~Sign())&KSignMask));
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TInteger::CopyL(const TInteger& aInteger, TBool aAllowShrink)
sl@0: 	{
sl@0: 	if(aAllowShrink)
sl@0: 		{
sl@0: 		CleanResizeL(aInteger.Size());
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		CleanGrowL(aInteger.Size());
sl@0: 		}
sl@0: 	Construct(aInteger);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TInteger::CopyL(TInt aInteger, TBool aAllowShrink)
sl@0: 	{
sl@0: 	if(aAllowShrink)
sl@0: 		{
sl@0: 		CleanResizeL(2);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		CleanGrowL(2);
sl@0: 		}
sl@0: 	Construct(aInteger);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C void TInteger::Set(const RInteger& aInteger)
sl@0: 	{
sl@0: 	assert(IsHeapBased());
sl@0: 	Mem::FillZ(Ptr(), WordsToBytes(Size()));
sl@0: 	User::Free(Ptr());
sl@0: 	iPtr = aInteger.iPtr;
sl@0: 	iSize = aInteger.iSize;
sl@0: 	}
sl@0: 
sl@0: RInteger TInteger::PositiveAddL(const TInteger &aA, const TInteger& aB) const
sl@0: 	{
sl@0: 	RInteger sum = RInteger::NewEmptyL(CryptoMax(aA.Size(), aB.Size()));
sl@0: 	const word aSize = aA.Size();
sl@0: 	const word bSize = aB.Size();
sl@0: 	const word* const aReg = aA.Ptr();
sl@0: 	const word* const bReg = aB.Ptr();
sl@0: 	word* const sumReg = sum.Ptr();
sl@0: 
sl@0: 	word carry;
sl@0: 	if (aSize == bSize)
sl@0: 		carry = Add(sumReg, aReg, bReg, aSize);
sl@0: 	else if (aSize > bSize)
sl@0: 		{
sl@0: 		carry = Add(sumReg, aReg, bReg, bSize);
sl@0: 		CopyWords(sumReg+bSize, aReg+bSize, aSize-bSize);
sl@0: 		carry = Increment(sumReg+bSize, aSize-bSize, carry);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		carry = Add(sumReg, aReg, bReg, aSize);
sl@0: 		CopyWords(sumReg+aSize, bReg+aSize, bSize-aSize);
sl@0: 		carry = Increment(sumReg+aSize, bSize-aSize, carry);
sl@0: 		}
sl@0: 
sl@0: 	if (carry)
sl@0: 		{
sl@0: 		CleanupStack::PushL(sum);
sl@0: 		sum.CleanGrowL(2*sum.Size());
sl@0: 		CleanupStack::Pop(&sum);
sl@0: 		sum.Ptr()[sum.Size()/2] = 1;
sl@0: 		}
sl@0: 	sum.SetSign(TInteger::EPositive);
sl@0: 	return sum;
sl@0: 	}
sl@0: 
sl@0: RInteger TInteger::PositiveSubtractL(const TInteger &aA, const TInteger& aB) const
sl@0: 	{
sl@0: 	RInteger diff = RInteger::NewEmptyL(CryptoMax(aA.Size(), aB.Size()));
sl@0: 	unsigned aSize = aA.WordCount();
sl@0: 	aSize += aSize%2;
sl@0: 	unsigned bSize = aB.WordCount();
sl@0: 	bSize += bSize%2;
sl@0: 	const word* const aReg = aA.Ptr();
sl@0: 	const word* const bReg = aB.Ptr();
sl@0: 	word* const diffReg = diff.Ptr();
sl@0: 
sl@0: 	if (aSize == bSize)
sl@0: 		{
sl@0: 		if (Compare(aReg, bReg, aSize) >= 0)
sl@0: 			{
sl@0: 			Subtract(diffReg, aReg, bReg, aSize);
sl@0: 			diff.SetSign(TInteger::EPositive);
sl@0: 			}
sl@0: 		else
sl@0: 			{
sl@0: 			Subtract(diffReg, bReg, aReg, aSize);
sl@0: 			diff.SetSign(TInteger::ENegative);
sl@0: 			}
sl@0: 		}
sl@0: 	else if (aSize > bSize)
sl@0: 		{
sl@0: 		word borrow = Subtract(diffReg, aReg, bReg, bSize);
sl@0: 		CopyWords(diffReg+bSize, aReg+bSize, aSize-bSize);
sl@0: 		borrow = Decrement(diffReg+bSize, aSize-bSize, borrow);
sl@0: 		assert(!borrow);
sl@0: 		diff.SetSign(TInteger::EPositive);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		word borrow = Subtract(diffReg, bReg, aReg, aSize);
sl@0: 		CopyWords(diffReg+aSize, bReg+aSize, bSize-aSize);
sl@0: 		borrow = Decrement(diffReg+aSize, bSize-aSize, borrow);
sl@0: 		assert(!borrow);
sl@0: 		diff.SetSign(TInteger::ENegative);
sl@0: 		}
sl@0: 	return diff;
sl@0: 	}
sl@0: 
sl@0: RInteger TInteger::PositiveMultiplyL(const TInteger &aA, const TInteger &aB) const
sl@0: 	{
sl@0: 	unsigned aSize = RoundupSize(aA.WordCount());
sl@0: 	unsigned bSize = RoundupSize(aB.WordCount());
sl@0: 
sl@0: 	RInteger product = RInteger::NewEmptyL(aSize+bSize);
sl@0: 	CleanupClosePushL(product);
sl@0: 
sl@0: 	RInteger workspace = RInteger::NewEmptyL(aSize + bSize);
sl@0: 	AsymmetricMultiply(product.Ptr(), workspace.Ptr(), aA.Ptr(), aSize, aB.Ptr(), 
sl@0: 		bSize);
sl@0: 	workspace.Close();
sl@0: 	CleanupStack::Pop(&product);
sl@0: 	return product;
sl@0: 	}
sl@0: 
sl@0: TUint TInteger::Modulo(const TInteger& aDividend, TUint aDivisor) const
sl@0: 	{
sl@0: 	assert(aDivisor);
sl@0: 	TUint i = aDividend.WordCount();
sl@0: 	TUint remainder = 0;
sl@0: 	while(i--)
sl@0: 		{
sl@0: 		remainder = TUint(MAKE_DWORD(aDividend.Ptr()[i], remainder) % aDivisor);
sl@0: 		}
sl@0: 	return remainder;
sl@0: 	}
sl@0: 
sl@0: void TInteger::PositiveDivideL(RInteger &aRemainder, RInteger &aQuotient,
sl@0: 	const TInteger &aDividend, const TInteger &aDivisor) const
sl@0: 	{
sl@0: 	unsigned dividendSize = aDividend.WordCount();
sl@0: 	unsigned divisorSize = aDivisor.WordCount();
sl@0: 
sl@0: 	if (!divisorSize)
sl@0: 		{
sl@0: 		User::Leave(KErrDivideByZero);
sl@0: 		}
sl@0: 
sl@0: 	if (aDividend.UnsignedCompare(aDivisor) == -1)
sl@0: 		{
sl@0: 		aRemainder.CreateNewL(aDividend.Size());
sl@0: 		CleanupStack::PushL(aRemainder);
sl@0: 		aRemainder.CopyL(aDividend); //set remainder to a
sl@0: 		aRemainder.SetSign(TInteger::EPositive);
sl@0: 		aQuotient.CleanNewL(2); //Set quotient to zero
sl@0: 		CleanupStack::Pop(&aRemainder);
sl@0: 		return;
sl@0: 		}
sl@0: 
sl@0: 	dividendSize += dividendSize%2;	// round up to next even number
sl@0: 	divisorSize += divisorSize%2;
sl@0: 
sl@0: 	aRemainder.CleanNewL(divisorSize);
sl@0: 	CleanupStack::PushL(aRemainder);
sl@0: 	aQuotient.CleanNewL(dividendSize-divisorSize+2);
sl@0: 	CleanupStack::PushL(aQuotient);
sl@0: 
sl@0: 	RInteger T = RInteger::NewEmptyL(dividendSize+2*divisorSize+4);
sl@0: 	Divide(aRemainder.Ptr(), aQuotient.Ptr(), T.Ptr(), aDividend.Ptr(), 
sl@0: 		dividendSize, aDivisor.Ptr(), divisorSize);
sl@0: 	T.Close();
sl@0: 	CleanupStack::Pop(2, &aRemainder); //aQuotient, aRemainder
sl@0: 	}
sl@0: 
sl@0: void TInteger::DivideL(RInteger& aRemainder, RInteger& aQuotient, 
sl@0: 	const TInteger& aDividend, const TInteger& aDivisor) const
sl@0:     {
sl@0:     PositiveDivideL(aRemainder, aQuotient, aDividend, aDivisor);
sl@0: 
sl@0:     if (aDividend.IsNegative())
sl@0:         {
sl@0:         aQuotient.Negate();
sl@0:         if (aRemainder.NotZero())
sl@0:             {
sl@0:             --aQuotient;
sl@0: 			assert(aRemainder.Size() <= aDivisor.Size());
sl@0: 			Subtract(aRemainder.Ptr(), aDivisor.Ptr(), aRemainder.Ptr(), 
sl@0: 				aRemainder.Size());
sl@0:             }
sl@0:         }
sl@0: 
sl@0:     if (aDivisor.IsNegative())
sl@0:         aQuotient.Negate();
sl@0:     }
sl@0: 
sl@0: void TInteger::RandomizeL(TUint aBits, TRandomAttribute aAttr)
sl@0: 	{
sl@0: 	if(!aBits)
sl@0: 		{
sl@0: 		return;
sl@0: 		}
sl@0: 	const TUint bytes = BitsToBytes(aBits);
sl@0: 	const TUint words = BitsToWords(aBits);
sl@0: 	CleanGrowL(words);
sl@0: 	TPtr8 buf((TUint8*)(Ptr()), bytes, WordsToBytes(Size()));
sl@0: 	TUint bitpos = aBits % BYTE_BITS;
sl@0: 	TRAPD(err, GenerateRandomBytesL(buf));
sl@0: 	if((err != KErrNone) && (err != KErrNotSecure))
sl@0: 	    User::Leave(err);
sl@0: 	//mask with 0 all bits above the num requested in the most significant byte
sl@0: 	if(bitpos)
sl@0: 		{
sl@0: 		buf[bytes-1] = TUint8( buf[bytes-1] & ((1L << bitpos) - 1) );
sl@0: 		}
sl@0: 	//set most significant (top) bit 
sl@0: 	if(aAttr == ETopBitSet || aAttr == ETop2BitsSet)
sl@0: 		{
sl@0: 		SetBit(aBits-1); //Set bit counts from 0
sl@0: 		assert(BitCount() == aBits);
sl@0: 		assert(Bit(aBits-1));
sl@0: 		}
sl@0: 	//set 2nd bit from top
sl@0: 	if(aAttr == ETop2BitsSet)
sl@0: 		{
sl@0: 		SetBit(aBits-2); //Set bit counts from 0
sl@0: 		assert(BitCount() == aBits);
sl@0: 		assert(Bit(aBits-1));
sl@0: 		assert(Bit(aBits-2));
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void TInteger::RandomizeL(const TInteger& aMin, const TInteger& aMax)
sl@0: 	{
sl@0: 	assert(aMax > aMin);
sl@0: 	assert(aMin.NotNegative());
sl@0: 	RInteger range = RInteger::NewL(aMax);
sl@0: 	CleanupStack::PushL(range);
sl@0: 	range -= aMin;
sl@0: 	const TUint bits = range.BitCount();
sl@0: 
sl@0: 	//if we find a number < range then aMin+range < aMax 
sl@0: 	do
sl@0: 		{
sl@0: 		RandomizeL(bits, EAllBitsRandom);
sl@0: 		} 
sl@0: 	while(*this > range);
sl@0: 
sl@0: 	*this += aMin;
sl@0: 	CleanupStack::PopAndDestroy(&range);
sl@0: 	}
sl@0: 
sl@0: /* void PrimeRandomizeL(TUint aBits, TRandomAttribute aAttr)
sl@0:  * and all primality related functions are implemented in primes.cpp */
sl@0: 
sl@0: void TInteger::CreateNewL(TUint aNewSize)
sl@0: 	{
sl@0: 	//should only be called on construction
sl@0: 	assert(!iPtr);
sl@0: 	
sl@0: 	TUint newSize = RoundupSize(aNewSize);
sl@0: 	SetPtr((TUint*)User::AllocL(WordsToBytes(newSize)));
sl@0: 	SetSize(newSize);
sl@0: 	SetHeapBased();
sl@0: 	}
sl@0: 
sl@0: void TInteger::CleanNewL(TUint aNewSize)
sl@0: 	{
sl@0: 	CreateNewL(aNewSize);
sl@0: 	Mem::FillZ(Ptr(), WordsToBytes(Size())); //clear integer storage
sl@0: 	}
sl@0: 
sl@0: void TInteger::CleanGrowL(TUint aNewSize)
sl@0: 	{
sl@0: 	assert(IsHeapBased());
sl@0: 	TUint newSize = RoundupSize(aNewSize);
sl@0: 	TUint oldSize = Size();
sl@0: 	if(newSize > oldSize)
sl@0: 		{
sl@0: 		TUint* oldPtr = Ptr();
sl@0: 		//1) allocate new memory and set ptr and size
sl@0: 		SetPtr((TUint*)User::AllocL(WordsToBytes(newSize)));
sl@0: 		SetSize(newSize);
sl@0: 		//2) copy old mem to new mem
sl@0: 		Mem::Copy(Ptr(), oldPtr, WordsToBytes(oldSize));
sl@0: 		//3) zero all old memory
sl@0: 		Mem::FillZ(oldPtr, WordsToBytes(oldSize));
sl@0: 		//4) give back old memory
sl@0: 		User::Free(oldPtr);
sl@0: 		//5) zero new memory from end of copy to end of growth
sl@0: 		Mem::FillZ(Ptr() + oldSize, WordsToBytes(newSize-oldSize));
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void TInteger::CleanResizeL(TUint aNewSize)
sl@0: 	{
sl@0: 	assert(IsHeapBased());
sl@0: 	TUint newSize = RoundupSize(aNewSize);
sl@0: 	TUint oldSize = Size();
sl@0: 	if(newSize > oldSize)
sl@0: 		{
sl@0: 		CleanGrowL(aNewSize);
sl@0: 		}
sl@0: 	else if(newSize < oldSize)
sl@0: 		{
sl@0: 		TUint* oldPtr = Ptr();
sl@0: 		//1) zero memory above newsize
sl@0: 		Mem::FillZ(oldPtr+WordsToBytes(aNewSize),WordsToBytes(oldSize-newSize));
sl@0: 		//2) ReAlloc cell.  Since our newsize is less than oldsize, it is
sl@0: 		//guarenteed not to move.  Thus this is just freeing part of our old
sl@0: 		//cell to the heap for other uses.
sl@0: 		SetPtr((TUint*)User::ReAllocL(Ptr(), WordsToBytes(newSize)));
sl@0: 		SetSize(newSize);
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger::TInteger() : iSize(0), iPtr(0)
sl@0: 	{
sl@0: 	}
sl@0: 
sl@0: void TInteger::Construct(const TDesC8& aValue)
sl@0: 	{
sl@0: 	assert(Size() >= BytesToWords(aValue.Size()));
sl@0: 	if(aValue.Size() > 0)
sl@0: 		{
sl@0: 		//People write numbers with the most significant digits first (big
sl@0: 		//endian) but we store our numbers in little endian.  Hence we need to
sl@0: 		//reverse the string by bytes.
sl@0: 
sl@0: 		TUint bytes = aValue.Size();
sl@0: 		TUint8* i = (TUint8*)Ptr();
sl@0: 		TUint8* j = (TUint8*)aValue.Ptr() + bytes;
sl@0: 
sl@0: 		//Swap the endianess of the number itself
sl@0: 		// (msb) 01 02 03 04 05 06 (lsb) becomes ->
sl@0: 		// (lsb) 06 05 04 03 02 01 (msb)
sl@0: 		while( j != (TUint8*)aValue.Ptr() )
sl@0: 			{
sl@0: 			*i++ = *--j;
sl@0: 			}
sl@0: 		Mem::FillZ((TUint8*)Ptr() + bytes, WordsToBytes(Size()) - bytes);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		//if size is zero, we zero the whole register
sl@0: 		Mem::FillZ((TUint8*)Ptr(), WordsToBytes(Size()));
sl@0: 		}
sl@0: 	SetSign(EPositive);
sl@0: 	}
sl@0: 
sl@0: void TInteger::Construct(const TInteger& aInteger)
sl@0: 	{
sl@0: 	assert(Size() >= aInteger.Size());
sl@0: 	CopyWords(Ptr(), aInteger.Ptr(), aInteger.Size());
sl@0: 	if(Size() > aInteger.Size())
sl@0: 		{
sl@0: 		Mem::FillZ(Ptr()+aInteger.Size(), WordsToBytes(Size()-aInteger.Size()));
sl@0: 		}
sl@0: 	SetSign(aInteger.Sign());
sl@0: 	}
sl@0: 
sl@0: void TInteger::Construct(TInt aInteger)
sl@0: 	{
sl@0: 	Construct((TUint)aInteger);
sl@0: 	if(aInteger < 0)
sl@0: 		{
sl@0: 		SetSign(ENegative);
sl@0: 		Ptr()[0] = -aInteger;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void TInteger::Construct(TUint aInteger)
sl@0: 	{
sl@0: 	assert(Size() >= 2);
sl@0: 	SetSign(EPositive);
sl@0: 	Ptr()[0] = aInteger;
sl@0: 	Mem::FillZ(Ptr()+1, WordsToBytes(Size()-1));
sl@0: 	}
sl@0: 
sl@0: void TInteger::ConstructStack(TUint aWords, TUint aInteger)
sl@0: 	{
sl@0: 	SetPtr((TUint*)(this)+2);
sl@0: 	//SetStackBased(); //Not strictly needed as stackbased is a 0 at bit 1
sl@0: 	SetSize(aWords);
sl@0: 	assert(Size() >= 2);
sl@0: 	Ptr()[0] = aInteger;
sl@0: 	Mem::FillZ(&(Ptr()[1]), WordsToBytes(Size()-1));
sl@0: 	}
sl@0: 
sl@0: void TInteger::ConstructStack(TUint aWords, const TInteger& aInteger)
sl@0: 	{
sl@0: 	SetPtr((TUint*)(this)+2);
sl@0: 	//SetStackBased(); //Not strictly needed as stackbased is a 0 at bit 1
sl@0: 	SetSize(aWords);
sl@0: 	assert( Size() >= RoundupSize(aInteger.WordCount()) );
sl@0: 	CopyWords(Ptr(), aInteger.Ptr(), aInteger.Size());
sl@0: 	Mem::FillZ(Ptr()+aInteger.Size(), WordsToBytes(Size()-aInteger.Size()));
sl@0: 	}
sl@0: 
sl@0: // Methods are excluded from coverage due to the problem with BullsEye on ONB.
sl@0: // Manually verified that these methods are functionally covered.
sl@0: #ifdef _BullseyeCoverage
sl@0: #pragma suppress_warnings on
sl@0: #pragma BullseyeCoverage off
sl@0: #pragma suppress_warnings off
sl@0: #endif
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator/=(TInt aOperand)
sl@0: 	{
sl@0: 	TStackInteger64 operand(aOperand);
sl@0: 	*this /= operand;
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInteger& TInteger::operator%=(TInt aOperand)
sl@0: 	{
sl@0: 	TStackInteger64 operand(aOperand);
sl@0: 	assert(operand.NotNegative());
sl@0: 	*this %= operand;
sl@0: 	return *this;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C TInt TInteger::ConvertToLongL(void) const
sl@0: 	{
sl@0: 	if(!IsConvertableToLong())
sl@0: 		{
sl@0: 		User::Leave(KErrTotalLossOfPrecision);
sl@0: 		}
sl@0: 	return ConvertToLong();
sl@0: 	}
sl@0: 
sl@0: TInt TInteger::ConvertToLong(void) const
sl@0: 	{
sl@0: 	TUint value = ConvertToUnsignedLong();
sl@0: 	return Sign() == EPositive ? value : -(static_cast<TInt>(value));
sl@0: 	}
sl@0: 
sl@0: TBool TInteger::IsConvertableToLong(void) const
sl@0: 	{
sl@0: 	if(WordCount() > 1)
sl@0: 		{
sl@0: 		return EFalse;
sl@0: 		}
sl@0: 	TUint value = (Ptr())[0];
sl@0: 	if(Sign() == EPositive)
sl@0: 		{
sl@0: 		return static_cast<TInt>(value) >= 0;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		return -(static_cast<TInt>(value)) < 0;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::SquaredL() const
sl@0: 	{
sl@0: 	//PositiveMultiplyL optimises for the squaring case already
sl@0: 	//Any number squared is positive, no need for negative handling in TimesL
sl@0: 	return PositiveMultiplyL(*this, *this);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::DividedByL(TUint aOperand) const
sl@0: 	{
sl@0: 	TUint remainder;
sl@0: 	RInteger quotient;
sl@0: 	DivideL(remainder, quotient, *this, aOperand);
sl@0: 	return quotient;
sl@0: 	}
sl@0: 
sl@0: EXPORT_C RInteger TInteger::ExponentiateL(const TInteger& aExponent) const
sl@0: 	{
sl@0: 	//See HAC 14.85
sl@0: 
sl@0: 	// 1.1 Precomputation
sl@0: 	// g1 <- g
sl@0: 	// g2 <- g^2
sl@0: 	RInteger g2 = SquaredL();
sl@0: 	CleanupStack::PushL(g2);
sl@0: 	RInteger g1 = RInteger::NewL(*this);
sl@0: 	CleanupStack::PushL(g1);
sl@0: 	TWindowSlider slider(aExponent);
sl@0: 
sl@0: 	// 1.2 
sl@0: 	// For i from 1 to (2^(k-1) -1) do g2i+1 <- g2i-1 * g2
sl@0: 	TUint count = (1 << (slider.WindowSize()-1)) - 1; //2^(k-1) -1
sl@0: 	RRArray<RInteger> powerArray(count+1); //+1 because we append g1
sl@0: 	powerArray.AppendL(g1);
sl@0: 	CleanupStack::Pop(); //g1
sl@0: 	CleanupClosePushL(powerArray);
sl@0: 	for(TUint k=1; k <= count; k++)
sl@0: 		{
sl@0: 		RInteger g2iplus1 = g2.TimesL(powerArray[k-1]);
sl@0: 		powerArray.AppendL(g2iplus1);
sl@0: 		}
sl@0: 
sl@0: 	// 2 A <- 1, i <- t
sl@0: 	RInteger A = RInteger::NewL(One());
sl@0: 	CleanupStack::PushL(A);
sl@0: 	TInt i = aExponent.BitCount() - 1;
sl@0: 
sl@0: 	// 3 While i>=0 do:
sl@0: 	while( i>=0 )
sl@0: 		{
sl@0: 		// 3.1 If ei == 0 then A <- A^2
sl@0: 		if(!aExponent.Bit(i))
sl@0: 			{
sl@0: 			A *= A;
sl@0: 			i--;
sl@0: 			}
sl@0: 		// 3.2 Find longest bitstring ei,ei-1,...,el s.t. i-l+1<=k and el==1
sl@0: 		// and do:
sl@0: 		// A <- (A^2^(i-l+1)) * g[the index indicated by the bitstring value]
sl@0: 		else
sl@0: 			{
sl@0: 			slider.FindNextWindow(i);
sl@0: 			assert(slider.Length() >= 1);
sl@0: 			for(TUint j=0; j<slider.Length(); j++)
sl@0: 				{
sl@0: 				A *= A;
sl@0: 				}
sl@0: 			A *= powerArray[slider.Value()>>1];
sl@0: 			i -= slider.Length();
sl@0: 			}
sl@0: 		}
sl@0: 	CleanupStack::Pop(&A);
sl@0: 	CleanupStack::PopAndDestroy(2, &g2); //powerArray, g2
sl@0: 	return A;
sl@0: 	}
sl@0: 
sl@0: void TInteger::DivideL(TUint& aRemainder, RInteger& aQuotient,
sl@0: 	const TInteger& aDividend, TUint aDivisor) const
sl@0: 	{
sl@0: 	if(!aDivisor)
sl@0: 		{
sl@0: 		User::Leave(KErrDivideByZero);
sl@0: 		}
sl@0: 	
sl@0: 	TUint i = aDividend.WordCount();
sl@0: 	aQuotient.CleanNewL(RoundupSize(i));
sl@0: 	PositiveDivide(aRemainder, aQuotient, aDividend, aDivisor);
sl@0: 
sl@0: 	if(aDividend.NotNegative())
sl@0: 		{
sl@0: 		aQuotient.SetSign(TInteger::EPositive);
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		aQuotient.SetSign(TInteger::ENegative);
sl@0: 		if(aRemainder)
sl@0: 			{
sl@0: 			--aQuotient;
sl@0: 			aRemainder = aDivisor = aRemainder;
sl@0: 			}
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: void TInteger::PositiveDivide(TUint& aRemainder, TInteger& aQuotient, 
sl@0: 	const TInteger& aDividend, TUint aDivisor) const
sl@0: 	{
sl@0: 	assert(aDivisor);
sl@0: 
sl@0: 	TUint i = aDividend.WordCount();
sl@0: 	assert(aQuotient.Size() >= RoundupSize(i));
sl@0: 	assert(aQuotient.Sign() == TInteger::EPositive);
sl@0: 	aRemainder = 0;
sl@0: 	while(i--)
sl@0: 		{
sl@0: 		aQuotient.Ptr()[i] = 
sl@0: 			TUint(MAKE_DWORD(aDividend.Ptr()[i], aRemainder) / aDivisor);
sl@0: 		aRemainder = 
sl@0: 			TUint(MAKE_DWORD(aDividend.Ptr()[i], aRemainder) % aDivisor);
sl@0: 		}
sl@0: 	}