/*
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
*/

/* AMCL BN Curve pairing functions */

//#define HAS_MAIN

#include "pair_ZZZ.h"

using namespace XXX;
using namespace YYY;

namespace ZZZ {
	static void PAIR_line(FP12 *,ECP2 *,ECP2 *,FP *,FP *);
	static void glv(BIG u[2],BIG);
	static void gs(BIG u[4],BIG);
}

/* Line function */
static void ZZZ::PAIR_line(FP12 *v,ECP2 *A,ECP2 *B,FP *Qx,FP *Qy)
{
	FP2 X1,Y1,T1,T2;
	FP2 XX,YY,ZZ,YZ;
    FP4 a,b,c;

	if (A==B)
    {
        /* doubling */
 		FP2_copy(&XX,&(A->x));	//FP2 XX=new FP2(A.getx());  //X
		FP2_copy(&YY,&(A->y));	//FP2 YY=new FP2(A.gety());  //Y
		FP2_copy(&ZZ,&(A->z));	//FP2 ZZ=new FP2(A.getz());  //Z


		FP2_copy(&YZ,&YY);		//FP2 YZ=new FP2(YY);        //Y 
		FP2_mul(&YZ,&YZ,&ZZ);	//YZ.mul(ZZ);                //YZ
		FP2_sqr(&XX,&XX);		//XX.sqr();	               //X^2
		FP2_sqr(&YY,&YY);		//YY.sqr();	               //Y^2
		FP2_sqr(&ZZ,&ZZ);		//ZZ.sqr();			       //Z^2
			
		FP2_imul(&YZ,&YZ,4);	//YZ.imul(4);
		FP2_neg(&YZ,&YZ);		//YZ.neg(); 
		FP2_norm(&YZ);			//YZ.norm();       //-4YZ

		FP2_imul(&XX,&XX,6);				//6X^2
		FP2_pmul(&XX,&XX,Qx);	            //6X^2.Xs

		FP2_imul(&ZZ,&ZZ,3*CURVE_B_I);	//3Bz^2 

		FP2_pmul(&YZ,&YZ,Qy);	//-4YZ.Ys

#if SEXTIC_TWIST_ZZZ==D_TYPE
		FP2_div_ip2(&ZZ);		//6(b/i)z^2
#endif
#if SEXTIC_TWIST_ZZZ==M_TYPE
		FP2_mul_ip(&ZZ);
		FP2_add(&ZZ,&ZZ,&ZZ);  // 6biz^2
		FP2_mul_ip(&YZ);
		FP2_norm(&YZ);	
#endif
		FP2_norm(&ZZ);			// 6bi.Z^2 

		FP2_add(&YY,&YY,&YY);	// 2y^2
		FP2_sub(&ZZ,&ZZ,&YY);	// 
		FP2_norm(&ZZ);			// 6b.Z^2-2Y^2

		FP4_from_FP2s(&a,&YZ,&ZZ); // -4YZ.Ys | 6b.Z^2-2Y^2 | 6X^2.Xs 
#if SEXTIC_TWIST_ZZZ==D_TYPE
		FP4_from_FP2(&b,&XX);	
		FP4_zero(&c);
#endif
#if SEXTIC_TWIST_ZZZ==M_TYPE
		FP4_zero(&b);
		FP4_from_FP2H(&c,&XX);
#endif

		ECP2_dbl(A);				//A.dbl();
    }
    else
    {
        /* addition */

		FP2_copy(&X1,&(A->x));		//FP2 X1=new FP2(A.getx());    // X1
		FP2_copy(&Y1,&(A->y));		//FP2 Y1=new FP2(A.gety());    // Y1
		FP2_copy(&T1,&(A->z));		//FP2 T1=new FP2(A.getz());    // Z1
			
		FP2_copy(&T2,&T1);			//FP2 T2=new FP2(A.getz());    // Z1

		FP2_mul(&T1,&T1,&(B->y));	//T1.mul(B.gety());    // T1=Z1.Y2 
		FP2_mul(&T2,&T2,&(B->x));	//T2.mul(B.getx());    // T2=Z1.X2

		FP2_sub(&X1,&X1,&T2);		//X1.sub(T2); 
		FP2_norm(&X1);				//X1.norm();  // X1=X1-Z1.X2
		FP2_sub(&Y1,&Y1,&T1);		//Y1.sub(T1); 
		FP2_norm(&Y1);				//Y1.norm();  // Y1=Y1-Z1.Y2

		FP2_copy(&T1,&X1);			//T1.copy(X1);            // T1=X1-Z1.X2

		FP2_pmul(&X1,&X1,Qy);		//X1.pmul(Qy);            // X1=(X1-Z1.X2).Ys
#if SEXTIC_TWIST_ZZZ==M_TYPE
		FP2_mul_ip(&X1);
		FP2_norm(&X1);
#endif

		FP2_mul(&T1,&T1,&(B->y));	//T1.mul(B.gety());       // T1=(X1-Z1.X2).Y2

		FP2_copy(&T2,&Y1);			//T2.copy(Y1);            // T2=Y1-Z1.Y2
		FP2_mul(&T2,&T2,&(B->x));	//T2.mul(B.getx());       // T2=(Y1-Z1.Y2).X2
		FP2_sub(&T2,&T2,&T1);		//T2.sub(T1); 
		FP2_norm(&T2);				//T2.norm();          // T2=(Y1-Z1.Y2).X2 - (X1-Z1.X2).Y2
		FP2_pmul(&Y1,&Y1,Qx);		//Y1.pmul(Qx);  
		FP2_neg(&Y1,&Y1);			//Y1.neg(); 
		FP2_norm(&Y1);				//Y1.norm(); // Y1=-(Y1-Z1.Y2).Xs

		FP4_from_FP2s(&a,&X1,&T2);	// (X1-Z1.X2).Ys  |  (Y1-Z1.Y2).X2 - (X1-Z1.X2).Y2  | - (Y1-Z1.Y2).Xs
#if SEXTIC_TWIST_ZZZ==D_TYPE
		FP4_from_FP2(&b,&Y1);		//b=new FP4(Y1);
		FP4_zero(&c);
#endif
#if SEXTIC_TWIST_ZZZ==M_TYPE
		FP4_zero(&b);
		FP4_from_FP2H(&c,&Y1);		//b=new FP4(Y1);
#endif
		ECP2_add(A,B);				//A.add(B);
    }

    FP12_from_FP4s(v,&a,&b,&c);
	v->type=FP_SPARSER;
}

/* prepare ate parameter, n=6u+2 (BN) or n=u (BLS), n3=3*n */
int ZZZ::PAIR_nbits(BIG n3,BIG n)
{
	BIG x;
    BIG_rcopy(x,CURVE_Bnx);

#if PAIRING_FRIENDLY_ZZZ==BN
    BIG_pmul(n,x,6);
#if SIGN_OF_X_ZZZ==POSITIVEX
	BIG_inc(n,2);
#else
    BIG_dec(n,2);
#endif

#else
    BIG_copy(n,x);
#endif

    BIG_norm(n);
	BIG_pmul(n3,n,3);
	BIG_norm(n3);

    return BIG_nbits(n3);
}

/*
	For multi-pairing, product of n pairings
	1. Declare FP12 array of length number of bits in Ate parameter
	2. Initialise this array by calling PAIR_initmp()
	3. Accumulate each pairing by calling PAIR_another() n times
	4. Call PAIR_miller()
	5. Call final exponentiation PAIR_fexp()
*/

/* prepare for multi-pairing */
void ZZZ::PAIR_initmp(FP12 r[])
{
	int i;
	for (i=ATE_BITS_ZZZ-1; i>=0; i--)
		FP12_one(&r[i]);
	return;
}

/* basic Miller loop */
void ZZZ::PAIR_miller(FP12 *res,FP12 r[])
{
	int i;
    FP12_one(res);
	for (i=ATE_BITS_ZZZ-1; i>=1; i--)
	{
		FP12_sqr(res,res);
		FP12_ssmul(res,&r[i]);
	}

#if SIGN_OF_X_ZZZ==NEGATIVEX
    FP12_conj(res,res);
#endif
	FP12_ssmul(res,&r[0]);
	return;
}

/* Accumulate another set of line functions for n-pairing */
void ZZZ::PAIR_another(FP12 r[],ECP2* PV,ECP* QV)
{
    int i,j,nb,bt;
	BIG x,n,n3;
    FP12 lv,lv2;
    ECP2 A,NP,P;
	ECP Q;
	FP Qx,Qy;
#if PAIRING_FRIENDLY_ZZZ==BN
	ECP2 K;
    FP2 X;
    FP_rcopy(&Qx,Fra);
    FP_rcopy(&Qy,Frb);
    FP2_from_FPs(&X,&Qx,&Qy);
#if SEXTIC_TWIST_ZZZ==M_TYPE
	FP2_inv(&X,&X);
	FP2_norm(&X);
#endif
#endif

	nb=PAIR_nbits(n3,n);

	ECP2_copy(&P,PV);
	ECP_copy(&Q,QV);

	ECP2_affine(&P);
	ECP_affine(&Q);

	FP_copy(&Qx,&(Q.x));
	FP_copy(&Qy,&(Q.y));

	ECP2_copy(&A,&P);
	ECP2_copy(&NP,&P); ECP2_neg(&NP);

	for (i=nb-2; i>=1; i--)
	{
		PAIR_line(&lv,&A,&A,&Qx,&Qy);

		bt=BIG_bit(n3,i)-BIG_bit(n,i); // bt=BIG_bit(n,i);
		if (bt==1)
		{
			PAIR_line(&lv2,&A,&P,&Qx,&Qy);
			FP12_smul(&lv,&lv2);
		}
		if (bt==-1)
		{
			PAIR_line(&lv2,&A,&NP,&Qx,&Qy);
			FP12_smul(&lv,&lv2);
		}
		FP12_ssmul(&r[i],&lv);
	}

#if PAIRING_FRIENDLY_ZZZ==BN

#if SIGN_OF_X_ZZZ==NEGATIVEX
	ECP2_neg(&A);
#endif

	ECP2_copy(&K,&P);
	ECP2_frob(&K,&X);
	PAIR_line(&lv,&A,&K,&Qx,&Qy);
	ECP2_frob(&K,&X);
	ECP2_neg(&K);
	PAIR_line(&lv2,&A,&K,&Qx,&Qy);
	FP12_smul(&lv,&lv2);
	FP12_ssmul(&r[0],&lv);

#endif
}

/* Optimal single R-ate pairing r=e(P,Q) */
void ZZZ::PAIR_ate(FP12 *r,ECP2 *P1,ECP *Q1)
{
    BIG x,n,n3;
	FP Qx,Qy;
    int i,nb,bt;
    ECP2 A,NP,P;
	ECP Q;
    FP12 lv,lv2;
#if PAIRING_FRIENDLY_ZZZ==BN
    ECP2 KA;
    FP2 X;

    FP_rcopy(&Qx,Fra);
    FP_rcopy(&Qy,Frb);
    FP2_from_FPs(&X,&Qx,&Qy);

#if SEXTIC_TWIST_ZZZ==M_TYPE
	FP2_inv(&X,&X);
	FP2_norm(&X);
#endif

#endif

	nb=PAIR_nbits(n3,n);

	ECP2_copy(&P,P1);
	ECP_copy(&Q,Q1);

	ECP2_affine(&P);
	ECP_affine(&Q);

    FP_copy(&Qx,&(Q.x));
    FP_copy(&Qy,&(Q.y));

    ECP2_copy(&A,&P);
	ECP2_copy(&NP,&P); ECP2_neg(&NP);

    FP12_one(r);

    /* Main Miller Loop */
    for (i=nb-2; i>=1; i--)
    {
		FP12_sqr(r,r);
        PAIR_line(&lv,&A,&A,&Qx,&Qy);

		bt=BIG_bit(n3,i)-BIG_bit(n,i); // bt=BIG_bit(n,i);
        if (bt==1)
        {
            PAIR_line(&lv2,&A,&P,&Qx,&Qy);
            FP12_smul(&lv,&lv2);
        }
		if (bt==-1)
		{
            PAIR_line(&lv2,&A,&NP,&Qx,&Qy);
            FP12_smul(&lv,&lv2);
		}
		FP12_ssmul(r,&lv);
    }

#if SIGN_OF_X_ZZZ==NEGATIVEX
    FP12_conj(r,r);
#endif

    /* R-ate fixup required for BN curves */
#if PAIRING_FRIENDLY_ZZZ==BN

#if SIGN_OF_X_ZZZ==NEGATIVEX
    ECP2_neg(&A);
#endif

    ECP2_copy(&KA,&P);
    ECP2_frob(&KA,&X);
    PAIR_line(&lv,&A,&KA,&Qx,&Qy);
    ECP2_frob(&KA,&X);
    ECP2_neg(&KA);
    PAIR_line(&lv2,&A,&KA,&Qx,&Qy);
	FP12_smul(&lv,&lv2);
    FP12_ssmul(r,&lv);
#endif
}

/* Optimal R-ate double pairing e(P,Q).e(R,S) */
void ZZZ::PAIR_double_ate(FP12 *r,ECP2 *P1,ECP *Q1,ECP2 *R1,ECP *S1)
{

    BIG x,n,n3;
	FP Qx,Qy,Sx,Sy;
    int i,nb,bt;
    ECP2 A,B,NP,NR,P,R;
	ECP Q,S;
    FP12 lv,lv2;
#if PAIRING_FRIENDLY_ZZZ==BN
    ECP2 K;
    FP2 X;

    FP_rcopy(&Qx,Fra);
    FP_rcopy(&Qy,Frb);
    FP2_from_FPs(&X,&Qx,&Qy);

#if SEXTIC_TWIST_ZZZ==M_TYPE
	FP2_inv(&X,&X);
	FP2_norm(&X);
#endif

#endif
	nb=PAIR_nbits(n3,n);

	ECP2_copy(&P,P1);
	ECP_copy(&Q,Q1);

	ECP2_affine(&P);
	ECP_affine(&Q);

	ECP2_copy(&R,R1);
	ECP_copy(&S,S1);

	ECP2_affine(&R);
	ECP_affine(&S);

    FP_copy(&Qx,&(Q.x));
    FP_copy(&Qy,&(Q.y));

    FP_copy(&Sx,&(S.x));
    FP_copy(&Sy,&(S.y));

    ECP2_copy(&A,&P);
    ECP2_copy(&B,&R);

	ECP2_copy(&NP,&P); ECP2_neg(&NP);
	ECP2_copy(&NR,&R); ECP2_neg(&NR);

    FP12_one(r);

    /* Main Miller Loop */
    for (i=nb-2; i>=1; i--)
    {
        FP12_sqr(r,r);
        PAIR_line(&lv,&A,&A,&Qx,&Qy);
        PAIR_line(&lv2,&B,&B,&Sx,&Sy);
		FP12_smul(&lv,&lv2);
        FP12_ssmul(r,&lv);

		bt=BIG_bit(n3,i)-BIG_bit(n,i); // bt=BIG_bit(n,i);
        if (bt==1)
        {
            PAIR_line(&lv,&A,&P,&Qx,&Qy);
            PAIR_line(&lv2,&B,&R,&Sx,&Sy);
			FP12_smul(&lv,&lv2);
            FP12_ssmul(r,&lv);
        }
		if (bt==-1)
		{
            PAIR_line(&lv,&A,&NP,&Qx,&Qy);
            PAIR_line(&lv2,&B,&NR,&Sx,&Sy);
			FP12_smul(&lv,&lv2);
            FP12_ssmul(r,&lv);
		}
	}

#if SIGN_OF_X_ZZZ==NEGATIVEX
    FP12_conj(r,r);
#endif
    /* R-ate fixup required for BN curves */
#if PAIRING_FRIENDLY_ZZZ==BN

#if SIGN_OF_X_ZZZ==NEGATIVEX
    ECP2_neg(&A);
    ECP2_neg(&B);
#endif

    ECP2_copy(&K,&P);
    ECP2_frob(&K,&X);
    PAIR_line(&lv,&A,&K,&Qx,&Qy);
    ECP2_frob(&K,&X);
    ECP2_neg(&K);
    PAIR_line(&lv2,&A,&K,&Qx,&Qy);
	FP12_smul(&lv,&lv2);
    FP12_ssmul(r,&lv);

    ECP2_copy(&K,&R);
    ECP2_frob(&K,&X);
    PAIR_line(&lv,&B,&K,&Sx,&Sy);
    ECP2_frob(&K,&X);
    ECP2_neg(&K);
    PAIR_line(&lv2,&B,&K,&Sx,&Sy);
	FP12_smul(&lv,&lv2);
    FP12_ssmul(r,&lv);
#endif
}

/* final exponentiation - keep separate for multi-pairings and to avoid thrashing stack */
void ZZZ::PAIR_fexp(FP12 *r)
{
    FP2 X;
    BIG x;
	FP a,b;
    FP12 t0,y0,y1,y2,y3;

    BIG_rcopy(x,CURVE_Bnx);
    FP_rcopy(&a,Fra);
    FP_rcopy(&b,Frb);
    FP2_from_FPs(&X,&a,&b);

    /* Easy part of final exp */

    FP12_inv(&t0,r);
    FP12_conj(r,r);

    FP12_mul(r,&t0);
    FP12_copy(&t0,r);

    FP12_frob(r,&X);
    FP12_frob(r,&X);
    FP12_mul(r,&t0);

	if (FP12_isunity(r))
	{
		FP12_zero(r);
		return;
	}
    /* Hard part of final exp - see Duquesne & Ghamman eprint 2015/192.pdf */
#if PAIRING_FRIENDLY_ZZZ==BN
    FP12_pow(&t0,r,x); // t0=f^-u
#if SIGN_OF_X_ZZZ==POSITIVEX
	FP12_conj(&t0,&t0);
#endif
    FP12_usqr(&y3,&t0); // y3=t0^2
    FP12_copy(&y0,&t0);
    FP12_mul(&y0,&y3); // y0=t0*y3
    FP12_copy(&y2,&y3);
    FP12_frob(&y2,&X); // y2=y3^p
    FP12_mul(&y2,&y3); //y2=y2*y3
    FP12_usqr(&y2,&y2); //y2=y2^2
    FP12_mul(&y2,&y3); // y2=y2*y3

    FP12_pow(&t0,&y0,x);  //t0=y0^-u
#if SIGN_OF_X_ZZZ==POSITIVEX
	FP12_conj(&t0,&t0);
#endif
    FP12_conj(&y0,r);     //y0=~r
    FP12_copy(&y1,&t0);
    FP12_frob(&y1,&X);
    FP12_frob(&y1,&X); //y1=t0^p^2
    FP12_mul(&y1,&y0); // y1=y0*y1
    FP12_conj(&t0,&t0); // t0=~t0
    FP12_copy(&y3,&t0);
    FP12_frob(&y3,&X); //y3=t0^p
    FP12_mul(&y3,&t0); // y3=t0*y3
    FP12_usqr(&t0,&t0); // t0=t0^2
    FP12_mul(&y1,&t0); // y1=t0*y1

    FP12_pow(&t0,&y3,x); // t0=y3^-u
#if SIGN_OF_X_ZZZ==POSITIVEX
	FP12_conj(&t0,&t0);
#endif
    FP12_usqr(&t0,&t0); //t0=t0^2
    FP12_conj(&t0,&t0); //t0=~t0
    FP12_mul(&y3,&t0); // y3=t0*y3

    FP12_frob(r,&X);
    FP12_copy(&y0,r);
    FP12_frob(r,&X);
    FP12_mul(&y0,r);
    FP12_frob(r,&X);
    FP12_mul(&y0,r);

    FP12_usqr(r,&y3);  //r=y3^2
    FP12_mul(r,&y2);   //r=y2*r
    FP12_copy(&y3,r);
    FP12_mul(&y3,&y0); // y3=r*y0
    FP12_mul(r,&y1); // r=r*y1
    FP12_usqr(r,r); // r=r^2
    FP12_mul(r,&y3); // r=r*y3
    FP12_reduce(r);
#else
// Ghamman & Fouotsa Method

    FP12_usqr(&y0,r);
    FP12_pow(&y1,&y0,x);
#if SIGN_OF_X_ZZZ==NEGATIVEX
	FP12_conj(&y1,&y1);
#endif

    BIG_fshr(x,1);
    FP12_pow(&y2,&y1,x);
#if SIGN_OF_X_ZZZ==NEGATIVEX
	FP12_conj(&y2,&y2);
#endif
    BIG_fshl(x,1); // x must be even
    FP12_conj(&y3,r);
    FP12_mul(&y1,&y3);

    FP12_conj(&y1,&y1);
    FP12_mul(&y1,&y2);

    FP12_pow(&y2,&y1,x);
#if SIGN_OF_X_ZZZ==NEGATIVEX
	FP12_conj(&y2,&y2);
#endif
    FP12_pow(&y3,&y2,x);
#if SIGN_OF_X_ZZZ==NEGATIVEX
	FP12_conj(&y3,&y3);
#endif
    FP12_conj(&y1,&y1);
    FP12_mul(&y3,&y1);

    FP12_conj(&y1,&y1);
    FP12_frob(&y1,&X);
    FP12_frob(&y1,&X);
    FP12_frob(&y1,&X);
    FP12_frob(&y2,&X);
    FP12_frob(&y2,&X);
    FP12_mul(&y1,&y2);

    FP12_pow(&y2,&y3,x);
#if SIGN_OF_X_ZZZ==NEGATIVEX
	FP12_conj(&y2,&y2);
#endif
    FP12_mul(&y2,&y0);
    FP12_mul(&y2,r);

    FP12_mul(&y1,&y2);
    FP12_copy(&y2,&y3);
    FP12_frob(&y2,&X);
    FP12_mul(&y1,&y2);
    FP12_copy(r,&y1);
    FP12_reduce(r);

#endif
}

#ifdef USE_GLV_ZZZ
/* GLV method */
static void ZZZ::glv(BIG u[2],BIG e)
{
#if PAIRING_FRIENDLY_ZZZ==BN
    int i,j;
    BIG v[2],t,q;
    DBIG d;
    BIG_rcopy(q,CURVE_Order);
    for (i=0; i<2; i++)
    {
        BIG_rcopy(t,CURVE_W[i]);
        BIG_mul(d,t,e);
        BIG_ddiv(v[i],d,q);
        BIG_zero(u[i]);
    }
    BIG_copy(u[0],e);
    for (i=0; i<2; i++)
        for (j=0; j<2; j++)
        {
            BIG_rcopy(t,CURVE_SB[j][i]);
            BIG_modmul(t,v[j],t,q);
            BIG_add(u[i],u[i],q);
            BIG_sub(u[i],u[i],t);
            BIG_mod(u[i],q);
        }

#else
// -(x^2).P = (Beta.x,y)

    BIG x,x2,q;
    BIG_rcopy(x,CURVE_Bnx);
    BIG_smul(x2,x,x);
    BIG_copy(u[0],e);
    BIG_mod(u[0],x2);
    BIG_copy(u[1],e);
    BIG_sdiv(u[1],x2);

    BIG_rcopy(q,CURVE_Order);
    BIG_sub(u[1],q,u[1]);

#endif

    return;
}
#endif // USE_GLV

/* Galbraith & Scott Method */
static void ZZZ::gs(BIG u[4],BIG e)
{
    int i;
#if PAIRING_FRIENDLY_ZZZ==BN
    int j;
    BIG v[4],t,q;
    DBIG d;
    BIG_rcopy(q,CURVE_Order);
    for (i=0; i<4; i++)
    {
        BIG_rcopy(t,CURVE_WB[i]);
        BIG_mul(d,t,e);
        BIG_ddiv(v[i],d,q);
        BIG_zero(u[i]);
    }

    BIG_copy(u[0],e);
    for (i=0; i<4; i++)
        for (j=0; j<4; j++)
        {
            BIG_rcopy(t,CURVE_BB[j][i]);
            BIG_modmul(t,v[j],t,q);
            BIG_add(u[i],u[i],q);
            BIG_sub(u[i],u[i],t);
            BIG_mod(u[i],q);
        }

#else

    BIG x,w,q;
	BIG_rcopy(q,CURVE_Order);
    BIG_rcopy(x,CURVE_Bnx);
    BIG_copy(w,e);

    for (i=0; i<3; i++)
    {
        BIG_copy(u[i],w);
        BIG_mod(u[i],x);
        BIG_sdiv(w,x);
    }
	BIG_copy(u[3],w);

/*  */
#if SIGN_OF_X_ZZZ==NEGATIVEX
	BIG_modneg(u[1],u[1],q);
	BIG_modneg(u[3],u[3],q);
#endif

#endif
    return;
}

/* Multiply P by e in group G1 */
void ZZZ::PAIR_G1mul(ECP *P,BIG e)
{
#ifdef USE_GLV_ZZZ   /* Note this method is patented */
    int np,nn;
    ECP Q;
	FP cru;
    BIG t,q;
    BIG u[2];

    BIG_rcopy(q,CURVE_Order);
    glv(u,e);

    ECP_copy(&Q,P); ECP_affine(&Q);
    FP_rcopy(&cru,CURVE_Cru);
    FP_mul(&(Q.x),&(Q.x),&cru);

    /* note that -a.B = a.(-B). Use a or -a depending on which is smaller */

    np=BIG_nbits(u[0]);
    BIG_modneg(t,u[0],q);
    nn=BIG_nbits(t);
    if (nn<np)
    {
        BIG_copy(u[0],t);
        ECP_neg(P);
    }

    np=BIG_nbits(u[1]);
    BIG_modneg(t,u[1],q);
    nn=BIG_nbits(t);
    if (nn<np)
    {
        BIG_copy(u[1],t);
        ECP_neg(&Q);
    }
    BIG_norm(u[0]);
    BIG_norm(u[1]);
    ECP_mul2(P,&Q,u[0],u[1]);

#else
    ECP_mul(P,e);
#endif
}

/* Multiply P by e in group G2 */
void ZZZ::PAIR_G2mul(ECP2 *P,BIG e)
{
#ifdef USE_GS_G2_ZZZ   /* Well I didn't patent it :) */
    int i,np,nn;
    ECP2 Q[4];
    FP2 X;
    FP fx,fy;
    BIG x,y,u[4];

    FP_rcopy(&fx,Fra);
    FP_rcopy(&fy,Frb);
    FP2_from_FPs(&X,&fx,&fy);

#if SEXTIC_TWIST_ZZZ==M_TYPE
	FP2_inv(&X,&X);
	FP2_norm(&X);
#endif

    BIG_rcopy(y,CURVE_Order);
    gs(u,e);


    ECP2_copy(&Q[0],P);
    for (i=1; i<4; i++)
    {
        ECP2_copy(&Q[i],&Q[i-1]);
        ECP2_frob(&Q[i],&X);
    }


    for (i=0; i<4; i++)
    {
        np=BIG_nbits(u[i]);
        BIG_modneg(x,u[i],y);
        nn=BIG_nbits(x);
        if (nn<np)
        {
            BIG_copy(u[i],x);
            ECP2_neg(&Q[i]);
        }
        BIG_norm(u[i]);  
    }

    ECP2_mul4(P,Q,u);

#else
    ECP2_mul(P,e);
#endif
}

/* f=f^e */
void ZZZ::PAIR_GTpow(FP12 *f,BIG e)
{
#ifdef USE_GS_GT_ZZZ   /* Note that this option requires a lot of RAM! Maybe better to use compressed XTR method, see fp4.c */
    int i,np,nn;
    FP12 g[4];
    FP2 X;
    BIG t,q;
	FP fx,fy;
    BIG u[4];

    FP_rcopy(&fx,Fra);
    FP_rcopy(&fy,Frb);
    FP2_from_FPs(&X,&fx,&fy);

    BIG_rcopy(q,CURVE_Order);
    gs(u,e);

    FP12_copy(&g[0],f);
    for (i=1; i<4; i++)
    {
        FP12_copy(&g[i],&g[i-1]);
        FP12_frob(&g[i],&X);
    }

    for (i=0; i<4; i++)
    {
        np=BIG_nbits(u[i]);
        BIG_modneg(t,u[i],q);
        nn=BIG_nbits(t);
        if (nn<np)
        {
            BIG_copy(u[i],t);
            FP12_conj(&g[i],&g[i]);
        }
        BIG_norm(u[i]);        
    }
    FP12_pow4(f,g,u);

#else
    FP12_pow(f,f,e);
#endif
}


#ifdef HAS_MAIN

int main()
{
    int i;
    char byt[32];
    csprng rng;
    BIG xa,xb,ya,yb,w,a,b,t1,q,u[2],v[4],m,r;
    ECP2 P,G;
    ECP Q,R;
    FP12 g,gp;
    FP4 t,c,cp,cpm1,cpm2;
    FP2 x,y,X;


    BIG_rcopy(a,CURVE_Fra);
    BIG_rcopy(b,CURVE_Frb);
    FP2_from_BIGs(&X,a,b);

    BIG_rcopy(xa,CURVE_Gx);
    BIG_rcopy(ya,CURVE_Gy);

    ECP_set(&Q,xa,ya);
    if (Q.inf) printf("Failed to set - point not on curve\n");
    else printf("G1 set success\n");

    printf("Q= ");
    ECP_output(&Q);
    printf("\n");

    BIG_rcopy(xa,CURVE_Pxa);
    BIG_rcopy(xb,CURVE_Pxb);
    BIG_rcopy(ya,CURVE_Pya);
    BIG_rcopy(yb,CURVE_Pyb);

    FP2_from_BIGs(&x,xa,xb);
    FP2_from_BIGs(&y,ya,yb);

    ECP2_set(&P,&x,&y);
    if (P.inf) printf("Failed to set - point not on curve\n");
    else printf("G2 set success\n");

    printf("P= ");
    ECP2_output(&P);
    printf("\n");

    for (i=0; i<1000; i++ )
    {
        PAIR_ate(&g,&P,&Q);
        PAIR_fexp(&g);
    }
    printf("g= ");
    FP12_output(&g);
    printf("\n");

}

#endif