C++ ECn::get方法代码示例

String CvSakke::to_string( const ECn& point )
{
	Big x, y;
	point.get(x, y);
	
	return "[" + to_string(x) + "," + to_string(y) + "]";
}

int main()
{
    ifstream common("mnt.ecs");      // MNT elliptic curve parameters
    ifstream private_key("bls_private.key");
    ofstream signature("bls_signature.sig");
    miracl* mip=&precision;
    ECn PM;
    Big x,s,p,q,B;
    int bits,A,lsb;

    common >> bits;
    mip->IOBASE=16;
    common >> p;
    common >> A;
    common >> B >> q;

    private_key >> s;

    ecurve(A,B,p,MR_PROJECTIVE);

    PM=hash_and_map((char *)"This a quick test of the method",32);

    cout << "Short message has been signed - signature in bls_signature.sig " << endl;

    PM*=s;

    lsb=PM.get(x);

    signature << x << endl;
    signature << lsb << endl;

    return 0;
}

int signatureofshorthash(unsigned char *sm,mr_unsign64 *smlen,const unsigned char *m,mr_unsign64 mlen,const unsigned char *sk,mr_unsign64 sklen)
{
    miracl* mip=mirsys(40,16);
    ECn PM;
    Big x,y,s,p,B;
    int lsb,bits;
    mip->IOBASE=16;

    p=ptext;
    B=Btext;

    ecurve((Big)-3,B,p,MR_PROJECTIVE);

    s=from_binary((int)sklen,(char *)sk);
    PM=hash_and_map((char *)m,32);
    PM*=s;
    lsb=PM.get(x);

    to_binary(x,20,(char *)sm,TRUE);
    *smlen=20;

    if (lsb) sm[0]|=0x80;

    return 0;
}

int main()
{
    ifstream common("common.ecs");    /* construct file I/O streams */
    ifstream private_key("private.ecs");
    ifstream message;
    ofstream signature;
    char ifname[50],ofname[50];
    ECn G;
    Big a,b,p,q,x,y,h,r,s,d,k;
    long seed;
    int bits;
    miracl *mip=&precision;

/* randomise */
    cout << "Enter 9 digit random number seed  = ";
    cin >> seed;
    irand(seed);

/* get common data */
    common >> bits;
    mip->IOBASE=16;
    common >> p >> a >> b >> q >> x >> y;
    mip->IOBASE=10;

/* calculate r - this can be done off-line,
   and hence amortized to almost nothing    */
    ecurve(a,b,p,MR_PROJECTIVE);
    G=ECn(x,y);
//	k="702232148019446860144825009548118511996283736794"; // test vector from http://www.secg.org/collateral/gec2.pdf
    k=rand(q);
    G*=k;            /* see ebrick.cpp for technique to speed this up */
    G.get(r);
    r%=q;

/* get private key of recipient */
    private_key >> d;

/* get message */
    cout << "file to be signed = " ;
    cin >> ifname;
    strcpy(ofname,ifname);
    strip(ofname);
    strcat(ofname,".ecs");
    message.open(ifname,ios::binary|ios::in); 
    if (!message)
    {
        cout << "Unable to open file " << ifname << "\n";
        return 0;
    }
    h=Hash(message);

/* calculate s */
    k=inverse(k,q);
    s=((h+d*r)*k)%q;
    signature.open(ofname);
    signature << r << endl;
    signature << s << endl;
    return 0;
}

ECn map_f(ECn& P,ZZn& zeta)
{
    ECn R;
    Big x,y;
    P.get(x,y);
    ZZn X=x;
    X=zeta*X; x=Big(X);
    if (!R.set(x,y)) cout << "something wrong in map_f" << endl;   
    return R;
}

BOOL ecap(ECn& P,ECn& Q,Big& order,ZZn& zeta,Big& cofactor,ZZn& res)
{
    BOOL Ok;
    Big Qx,Qy;
    ZZn bQx;

    Q.get(Qx,Qy);
    bQx=zeta*zeta*(ZZn)Qx;
    Ok=fast_tate_pairing(P,(ZZn)Qx,(ZZn)Qy,bQx,order,cofactor,res);

    if (Ok) return TRUE;
    return FALSE;
}

void BaseOT::PointToByteArray(BYTE* pBufIdx, int field_size, ECn &point)
{
	int itmp;
	Big bigtmp;
	//compress to x-point and y-bit and convert to byte array
	itmp = point.get(bigtmp);

	//first store the y-bit
	pBufIdx[0] = (BYTE) (itmp & 0x01);

	//then store the x-coordinate (sec-param/8 + 4 byte size)
	big_to_bytes(field_size, bigtmp.getbig(), (char*) pBufIdx+1, true);
}

BOOL ecap(ECn3& P,ECn& Q,Big& x,ZZn &X,ZZn18& r)
{
    BOOL Ok;
    Big xx,yy;
    ZZn Qx,Qy;

    Q.get(xx,yy); Qx=xx; Qy=yy;

    Ok=fast_pairing(P,Qx,Qy,x,X,r);

    if (Ok) return TRUE;
    return FALSE;
}

BOOL ecap(ECn& P,ECn& Q,Big& order,BOOL precomp,ZZn *store,ZZn2& res)
{
    ZZn  Qx;
    ZZn2 Qy;
    Big xx,yy;
  
    Q.get(xx,yy);
    Qx=-xx;
    Qy.set((Big)0,yy);

    return fast_tate_pairing(P,Qx,Qy,order,precomp,store,res);

}

int
ECnTochar (ECn &e, char *c, int s)
{

  Big x, y;
  e.get(x, y);
  int len = 0;
  int totlen = sizeof (int)*2;

  //  cout << "Entering ECnTochar" << endl;
  //   format: 4 bytes length, followed by the big
  if (s <= sizeof (int))
    return -1;
  // Code assumes epoint contains either nulls or bigs > 0
  s -= sizeof (int);
  c += sizeof (int);
  if (x.iszero()) {
    len = 0;
  } else {  
    len = to_binary (x, s, c, FALSE);
  }
  if (len < 0) {
    return -1;
  }

  memcpy ((char *)(c - sizeof(int)), (void *)&len, sizeof (int));

  totlen += len;
  s -= len;
  c += len;
  //    cout << "Len1 " << len << " x " << x;


  if (s <= sizeof (int))
    return -1;
  s -= sizeof (int);
  c += sizeof (int);
  len = to_binary (y, s, c, FALSE);
  if (len < 0)
    return -1;
  memcpy ((char *)(c - sizeof(int)), (void *)&len, sizeof (int));
  totlen += len;
  //  cout << "Len2 " << len << " y " << y;

  return totlen;
}

BOOL ecap(ECn2& P,ECn& Q,Big& x,ZZn2 &X,ZZn12& r)
{
	BOOL Ok;
	Big xx,yy;
	ZZn Qx,Qy;

	P.norm();

	cout<<"P:"<<P<<endl;

	Q.get(xx,yy); Qx=xx; Qy=yy;

	Ok=fast_pairing(P,Qx,Qy,x,X,r);

	if (Ok) return TRUE;
	return FALSE;
}

BOOL ecap(ECn& P,ECn& Q,Big& order,ZZn2& cube,ZZn2& res)
{
    ZZn2 Qx;
    ZZn  Qy,iy;
    Big xx,yy;

    Q.get(xx,yy);
    Qx=(ZZn)xx*cube;
    Qy=(ZZn)yy;

    iy=(ZZn)1/(Qy+1);
    Qx=-2*Qx*iy;
    Qy=(Qy-3)*iy;        // Q+=(0,1)

    if (fast_tate_pairing(P,Qx,Qy,order,res)) return TRUE;
    return FALSE;
}

BOOL ecap(ECn& P,ECn& Q,Big& order,ZZn2& cube,ZZn2& res)
{
     ZZn2 Qx,Qy;
     Big xx,yy;

#ifdef SCOTT
     ZZn a,b,x,y,ib,w,t1,y2,ib2;
#else
     ZZn2 lambda,ox;
#endif
     Q.get(xx,yy);
     Qx=(ZZn)xx*cube;
     Qy=(ZZn)yy;

#ifndef SCOTT
// point doubling
     lambda=(3*Qx*Qx)/(Qy+Qy);
     ox=Qx;
     Qx=lambda*lambda-(Qx+Qx);
     Qy=lambda*(ox-Qx)-Qy;
#else
// explicit point subtraction
     Qx.get(a,b);
     y=yy;
     ib=(ZZn)1/b;

     t1=a*b*b;
     y2=y*y;
     ib2=ib*ib;
     w=y2+2*t1;
     x=-w*ib2;
     y=-y*(w+t1)*(ib2*ib);
     Qx.set(x); Qy.set((ZZn)0,y);

#endif

     if (fast_tate_pairing(P,Qx,Qy,order,res)) return TRUE;
     return FALSE;
}

//.........这里部分代码省略.........
		Q=(p-1+t)*Q;                   // generator point in G2
		cru=(18*pow(x,3)-18*x*x+9*x-2);
	}

	if (strcmp(curvename,"BLS383")==0)
	{
		curve=20;
		printf("Curve= BLS383\n");
		strcpy(fieldname,curvename);
		mbits=383;
		words=(1+((mbits-1)/bb));
		curvetype=WEIERSTRASS;
		modtype=NOT_SPECIAL;
		curve_a=0;
	
		mip->IOBASE=16;
	//	x=(char *)"11000001000000040";              
		x=(char *)"10008000001001200";	// SIGN_OF_X is POSITIVE
		p=(pow(x,6)-2*pow(x,5)+2*pow(x,3)+x+1)/3;
		t=x+1;
		r=pow(x,4)-x*x+1;
		cof=(p+1-t)/r;

	//	gx=-2; gy=-1;
	//	curve_b=9;
		gx=1; gy=4;
		curve_b=15;
		ecurve((Big)0,curve_b,p,MR_AFFINE);
	//	mip->TWIST=MR_SEXTIC_D;
		mip->TWIST=MR_SEXTIC_M;

		P.set(gx,gy);
		P*=cof;
		P.get(gx,gy);

		//cout << "gx= " << gx << endl;
		//cout << "gy= " << gy << endl;
		//cout << "y^2= " << (gy*gy)%p << endl;
		//cout << "x^3+b= " << (gx*gx*gx+15)%p << endl;

		//while (!Q.set(randn2())) ; // probably not best way to choose this

		Xa=1;
		while (!Q.set(Xa))
		{
			Xa=Xa+(ZZn2)1;
		}

		TT=t*t-2*p;
		PP=p*p;
		FF=sqrt((4*PP-TT*TT)/3);
		np=PP+1-(-3*FF+TT)/2;  // 2 possibilities...

		Q=(np/r)*Q;

		zcru=pow((ZZn)2,(p-1)/3);
	//	zcru*=zcru;   // right cube root of unity
		cru=(Big)zcru;
	}

	if (strcmp(curvename,"BLS381")==0)
	{
		curve=21;
		printf("Curve= BLS381\n");
		strcpy(fieldname,curvename);
		mbits=381;

//.........这里部分代码省略.........
                    cout << setw(3) << (p+1-tau)%lp << flush; 
                }
                t[i]=tau;
                if ((p+1-tau)%lp==0)
                {
                    cout << " ***" << endl;
                    if (search && (!Edwards || lp!=4)) escape=TRUE;
                }
                else cout << endl;
                break;
            }
            cout << "\b\b\b";
        }
        for (jj=0;jj<low;jj++)
        {
            Pf[jj].clear();
            P2f[jj].clear();
            P3f[jj].clear();
        }
        if (escape) break;
    }
    Modulus.clear();

    for (i=0;i<=L+1;i++) 
    {
        P[i].clear(); // reclaim space
        P2[i].clear();
        P3[i].clear();
    }

    if (escape) {b+=1; continue;}
    Big order,ordermod;
    ordermod=1; for (i=0;i<nl-start_prime;i++) ordermod*=(int)l[start_prime+i];
    order=(p+1-CRT.eval(&t[start_prime]))%ordermod;    // get order mod product of primes

    nrp=kangaroo(p,order,ordermod);

	if (Edwards)
	{
		if (!prime(nrp/4) && search) {b+=1; continue; }
		else break;
	}
	else
	{
		if (!prime(nrp) && search) {b+=1; continue; }
		else break;
    }
	}
    if (fout) 
    {
        ECn P;
        ofile << bits(p) << endl;
        mip->IOBASE=16;
        ofile << p << endl;

        ofile << a << endl;
        ofile << b << endl;
    // generate a random point on the curve 
    // point will be of prime order for "ideal" curve, otherwise any point
		if (!Edwards)
		{
			do {
				x=rand(p);
			} while (!P.set(x,x));
			P.get(x,y);
			ofile << nrp << endl;