/*

* 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: 

*

*/

#include <asymmetrickeys.h>

#include <bigint.h>

#include "../common/inlines.h"

const TUint KFermat4 = 65537;

/* CRSAParameters */

EXPORT_C const TInteger& CRSAParameters::N(void) const

	{

	return iN;

	}

EXPORT_C CRSAParameters::~CRSAParameters(void)

	{

	iN.Close();

	}

EXPORT_C CRSAParameters::CRSAParameters(RInteger& aN) : iN(aN)

	{

	}

EXPORT_C CRSAParameters::CRSAParameters(void)

	{

	}

/* CRSAPublicKey */

EXPORT_C CRSAPublicKey* CRSAPublicKey::NewL(RInteger& aN, RInteger& aE)

	{

	CRSAPublicKey* self = NewLC(aN, aE);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CRSAPublicKey* CRSAPublicKey::NewLC(RInteger& aN, RInteger& aE)

	{

	CRSAPublicKey* self = new(ELeave) CRSAPublicKey(aN, aE);

	CleanupStack::PushL(self);

	self->ConstructL();

	return self;

	}

void CRSAPublicKey::ConstructL()

	{ 

	// Check that the modulus and exponent are positive integers 

	// as specified by RSA

	if(!N().IsPositive() || !E().IsPositive() || (E() <= 1))

		{

		// If we need to leave during construction we must release ownership

		// of the RInteger parameters that were passed in.

		// These parameters should be on the cleanup stack so if we don't 

		// release ownership they will be deleted twice, causing a panic

		iN = RInteger();

		iE = RInteger();

		User::Leave(KErrArgument);

		}

	}

EXPORT_C const TInteger& CRSAPublicKey::E(void) const

	{

	return iE;

	}

EXPORT_C CRSAPublicKey::CRSAPublicKey()

	{

	}

EXPORT_C CRSAPublicKey::CRSAPublicKey(RInteger& aN, RInteger& aE)

	: CRSAParameters(aN), iE(aE)

	{

	}

EXPORT_C CRSAPublicKey::~CRSAPublicKey(void)

	{

	iE.Close();

	}

/* CRSAPrivateKeyType */

CRSAPrivateKey::CRSAPrivateKey(const TRSAPrivateKeyType aKeyType, RInteger& aN)

:	CRSAParameters(aN), iKeyType(aKeyType)

{}

/* CRSAPrivateKeyStandard */

EXPORT_C CRSAPrivateKeyStandard* CRSAPrivateKeyStandard::NewL(RInteger& aN, 

	RInteger& aD)

	{

	CRSAPrivateKeyStandard* self = NewLC(aN, aD);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CRSAPrivateKeyStandard* CRSAPrivateKeyStandard::NewLC(RInteger& aN,

	RInteger& aD)

	{

	CRSAPrivateKeyStandard* self = new(ELeave) CRSAPrivateKeyStandard(aN, aD);

	CleanupStack::PushL(self);

	self->ConstructL();

	return self;

	}

void CRSAPrivateKeyStandard::ConstructL()

	{

	// Check that the modulus and exponent are positive integers

	if(!N().IsPositive() || !D().IsPositive() || (D() <= 1))

		{

		// If we need to leave during construction we must release ownership

		// of the RInteger parameters that were passed in.

		// These parameters should be on the cleanup stack so if we don't 

		// release ownership they will be deleted twice, causing a panic

		iN = RInteger();

		iD = RInteger();

		User::Leave(KErrArgument);

		}

	}

EXPORT_C const TInteger& CRSAPrivateKeyStandard::D(void) const

	{

	return iD;

	}

EXPORT_C CRSAPrivateKeyStandard::CRSAPrivateKeyStandard(RInteger& aN, 

	RInteger& aD) : CRSAPrivateKey(EStandard, aN), iD(aD)

	{

	}

EXPORT_C CRSAPrivateKeyStandard::~CRSAPrivateKeyStandard()

	{	

	iD.Close();

	}

/* CRSAPrivateKeyCRT */

EXPORT_C CRSAPrivateKeyCRT* CRSAPrivateKeyCRT::NewL(RInteger& aN, RInteger& aP,

	RInteger& aQ, RInteger& aDP, RInteger& aDQ, RInteger& aQInv)

	{

	CRSAPrivateKeyCRT* self = NewLC(aN, aP, aQ, aDP, aDQ, aQInv);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CRSAPrivateKeyCRT* CRSAPrivateKeyCRT::NewLC(RInteger& aN, RInteger& aP, 

	RInteger& aQ, RInteger& aDP, RInteger& aDQ, RInteger& aQInv)

	{

	CRSAPrivateKeyCRT* self = new(ELeave) CRSAPrivateKeyCRT(aN, aP, aQ, 

		aDP, aDQ, aQInv);

	CleanupStack::PushL(self);

	self->ConstructL();

	return self;

	}

EXPORT_C CRSAPrivateKeyCRT::CRSAPrivateKeyCRT(RInteger& aN, RInteger& aP, 

	RInteger& aQ, RInteger& aDP, RInteger& aDQ, RInteger& aQInv) 

	: CRSAPrivateKey(EStandardCRT, aN), iP(aP), iQ(aQ), iDP(aDP), iDQ(aDQ), 

		iQInv(aQInv)

	{

	}

void CRSAPrivateKeyCRT::ConstructL()

	{

	// Check that all parameters are positive integers

	if(!P().IsPositive() || !Q().IsPositive() || !DP().IsPositive() 

		|| !DQ().IsPositive() || !QInv().IsPositive())

		{

		// If we need to leave during construction we must release ownership

		// of the RInteger parameters that were passed in.

		// These parameters should be on the cleanup stack so if we don't 

		// release ownership they will be deleted twice, causing a panic

		iN = RInteger();

		iP = RInteger();

		iQ = RInteger();

		iDP = RInteger();

		iDQ = RInteger();

		iQInv = RInteger();

		User::Leave(KErrArgument);

		}

	}

EXPORT_C CRSAPrivateKeyCRT::~CRSAPrivateKeyCRT()

	{	

	iP.Close();

	iQ.Close();

	iDP.Close();

	iDQ.Close();

	iQInv.Close();

	}

EXPORT_C const TInteger& CRSAPrivateKeyCRT::P(void) const

	{

	return iP;

	}

EXPORT_C const TInteger& CRSAPrivateKeyCRT::Q(void) const

	{

	return iQ;

	}

EXPORT_C const TInteger& CRSAPrivateKeyCRT::DP(void) const

	{

	return iDP;

	}

EXPORT_C const TInteger& CRSAPrivateKeyCRT::DQ(void) const

	{

	return iDQ;

	}

EXPORT_C const TInteger& CRSAPrivateKeyCRT::QInv(void) const

	{

	return iQInv;

	}

/* CRSAKeyPair */

EXPORT_C CRSAKeyPair* CRSAKeyPair::NewL(TUint aModulusBits, 

	TRSAPrivateKeyType aKeyType /*= EStandardCRT*/)

	{

	CRSAKeyPair* self = NewLC(aModulusBits, aKeyType);

	CleanupStack::Pop();

	return self;

	}

EXPORT_C CRSAKeyPair* CRSAKeyPair::NewLC(TUint aModulusBits, 

	TRSAPrivateKeyType aKeyType /*= EStandardCRT*/)

	{

	CRSAKeyPair* self = new(ELeave) CRSAKeyPair();

	CleanupStack::PushL(self);

	self->ConstructL(aModulusBits, aKeyType, KFermat4);

	return self;

	}

EXPORT_C const CRSAPublicKey& CRSAKeyPair::PublicKey(void) const

	{

	return *iPublic;

	}

EXPORT_C const CRSAPrivateKey& CRSAKeyPair::PrivateKey(void) const

	{

	return *iPrivate;

	}

EXPORT_C CRSAKeyPair::~CRSAKeyPair(void) 

	{

	delete iPublic;

	delete iPrivate;

	}

EXPORT_C CRSAKeyPair::CRSAKeyPair(void)

	{

	}

void CRSAKeyPair::ConstructL(TUint aModulusBits, 

	TRSAPrivateKeyType aKeyType, TUint aPublicExponent)

	{

	RInteger e = RInteger::NewL(aPublicExponent);

	CleanupStack::PushL(e);

	RInteger p;

	RInteger q;

	//these make sure n is a least aModulusBits long

    TInt pbits=(aModulusBits+1)/2;

    TInt qbits=aModulusBits-pbits;

	//generate a prime p such that GCD(e,p-1) == 1

	for (;;)

		{

		p = RInteger::NewPrimeL(pbits,TInteger::ETop2BitsSet);

		CleanupStack::PushL(p);

		--p;

		RInteger gcd = e.GCDL(p);

		if( gcd == 1 )

			{

			++p;

			gcd.Close();

			//p is still on cleanup stack

			break;

			}

		CleanupStack::PopAndDestroy(&p);

		gcd.Close();

		}

	//generate a prime q such that GCD(e,q-1) == 1 && (p != q)

	for (;;)

		{

		q = RInteger::NewPrimeL(qbits,TInteger::ETop2BitsSet);

		CleanupStack::PushL(q);

		--q;

		RInteger gcd = e.GCDL(q);

		if( gcd == 1 )

			{

			++q;

			if( p != q )

				{

				gcd.Close();

				//q is still on cleanup stack

				break;

				}

			}

		CleanupStack::PopAndDestroy(&q);

		gcd.Close();

		}

	//make sure p > q

    if ( p < q)

        {

		TClassSwap(p,q);

        }

	//calculate n = p * q 

	RInteger n = p.TimesL(q);

	CleanupStack::PushL(n);

	--p;

	--q;

	//temp = (p-1)(q-1)

	RInteger temp = p.TimesL(q);

	CleanupStack::PushL(temp);

	//e * d = 1 mod ((p-1)(q-1)) 

	//d = e^(-1) mod ((p-1)(q-1))

	RInteger d = e.InverseModL(temp);

	CleanupStack::PopAndDestroy(&temp); //temp

	CleanupStack::PushL(d);

	if (aKeyType==EStandardCRT)

	{

		//calculate dP = d mod (p-1) 

		RInteger dP = d.ModuloL(p); //p is still p-1

		CleanupStack::PushL(dP);

		//calculate dQ = d mod (q-1) 

		RInteger dQ = d.ModuloL(q); //q is still q-1

		CleanupStack::PushL(dQ);

		++p;

		++q;

		//calculate inverse of qInv = q^(-1)mod(p)

		RInteger qInv = q.InverseModL(p);

		CleanupStack::PushL(qInv);

		iPrivate = CRSAPrivateKeyCRT::NewL(n,p,q,dP,dQ,qInv);

		CleanupStack::Pop(3, &dP); //qInv, dQ, dP

		CleanupStack::PopAndDestroy(&d); //d	

		CleanupStack::Pop(3, &p); //n, q, p

		//e is still on cleanup stack

	}

	else if (aKeyType==EStandard)

	{

		iPrivate = CRSAPrivateKeyStandard::NewL(n,d);

		CleanupStack::Pop(2, &n); //d, n

		CleanupStack::PopAndDestroy(2, &p); //q, p

		//e is still on cleanup stack

	}

	else

	{

		User::Leave(KErrNotSupported);

	}

	//make a copy of n for the public parameters

	RInteger n1 = RInteger::NewL(PrivateKey().N());

	CleanupStack::PushL(n1);

	iPublic = CRSAPublicKey::NewL(n1,e); 

	CleanupStack::Pop(2, &e); //n1, e

	}