471 lines
9.8 KiB
C++
471 lines
9.8 KiB
C++
|
|
/***************************************************************************
|
|
*
|
|
Copyright 2013 CertiVox UK Ltd. *
|
|
*
|
|
This file is part of CertiVox MIRACL Crypto SDK. *
|
|
*
|
|
The CertiVox MIRACL Crypto SDK provides developers with an *
|
|
extensive and efficient set of cryptographic functions. *
|
|
For further information about its features and functionalities please *
|
|
refer to http://www.certivox.com *
|
|
*
|
|
* The CertiVox MIRACL Crypto SDK is free software: you can *
|
|
redistribute it and/or modify it under the terms of the *
|
|
GNU Affero General Public License as published by the *
|
|
Free Software Foundation, either version 3 of the License, *
|
|
or (at your option) any later version. *
|
|
*
|
|
* The CertiVox MIRACL Crypto SDK is distributed in the hope *
|
|
that it will be useful, but WITHOUT ANY WARRANTY; without even the *
|
|
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
|
|
See the GNU Affero General Public License for more details. *
|
|
*
|
|
* You should have received a copy of the GNU Affero General Public *
|
|
License along with CertiVox MIRACL Crypto SDK. *
|
|
If not, see <http://www.gnu.org/licenses/>. *
|
|
*
|
|
You can be released from the requirements of the license by purchasing *
|
|
a commercial license. Buying such a license is mandatory as soon as you *
|
|
develop commercial activities involving the CertiVox MIRACL Crypto SDK *
|
|
without disclosing the source code of your own applications, or shipping *
|
|
the CertiVox MIRACL Crypto SDK with a closed source product. *
|
|
*
|
|
***************************************************************************/
|
|
/*
|
|
* MIRACL C++ Implementation file zzn8.cpp
|
|
*
|
|
* AUTHOR : M. Scott
|
|
*
|
|
* PURPOSE : Implementation of class ZZn8 (Arithmetic over n^8)
|
|
*
|
|
* WARNING: This class has been cobbled together for a specific use with
|
|
* the MIRACL library. It is not complete, and may not work in other
|
|
* applications
|
|
*
|
|
*/
|
|
|
|
#include "zzn8.h"
|
|
|
|
using namespace std;
|
|
|
|
// This will now work with p=1 mod 4 or p=3 mod 4
|
|
// In the later case an adjustment is needed
|
|
|
|
ZZn8& ZZn8::powq(const ZZn2& X)
|
|
{ // Fr is "Frobenius root"
|
|
ZZn2 XX=X*X; // square it to get Frobenius constant for ZZn4
|
|
if ((get_mip()->pmod8)%4==3) XX=txx(XX);
|
|
a.powq(XX);
|
|
b.powq(XX);
|
|
b*=X;
|
|
if ((get_mip()->pmod8)%4==3) b=tx(b);
|
|
return *this;
|
|
}
|
|
|
|
void ZZn8::get(ZZn4& x,ZZn4& y) const
|
|
{x=a; y=b;}
|
|
|
|
void ZZn8::get(ZZn4& x) const
|
|
{x=a; }
|
|
|
|
ZZn8& ZZn8::operator*=(const ZZn8& x)
|
|
{ // optimized to reduce constructor/destructor calls
|
|
if (&x==this)
|
|
{
|
|
/* See Stam & Lenstra, "Efficient subgroup exponentiation in Quadratic .. Extensions", CHES 2002 */
|
|
if (unitary)
|
|
{
|
|
ZZn4 t=b; t*=t;
|
|
b+=a; b*=b;
|
|
b-=t;
|
|
a=tx(t);
|
|
b-=a;
|
|
a+=a; a+=one();
|
|
b-=one();
|
|
// cout << "in here" << endl;
|
|
}
|
|
else
|
|
{
|
|
ZZn4 t=a; t+=b;
|
|
ZZn4 t2=a; t2+=tx(b);
|
|
t*=t2;
|
|
b*=a;
|
|
t-=b;
|
|
t-=tx(b);
|
|
b+=b;
|
|
a=t;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ZZn4 ac=a; ac*=x.a;
|
|
ZZn4 bd=b; bd*=x.b;
|
|
ZZn4 t=x.a; t+=x.b;
|
|
b+=a; b*=t; b-=ac; b-=bd;
|
|
a=ac; a+=tx(bd);
|
|
|
|
if (!x.unitary) unitary=FALSE;
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
ZZn8& ZZn8::operator/=(const ZZn4& x)
|
|
{
|
|
*this*=inverse(x);
|
|
unitary=FALSE;
|
|
return *this;
|
|
}
|
|
|
|
ZZn8& ZZn8::operator/=(const ZZn& x)
|
|
{
|
|
ZZn t=(ZZn)1/x;
|
|
a*=t;
|
|
b*=t;
|
|
unitary=FALSE;
|
|
return *this;
|
|
}
|
|
|
|
ZZn8& ZZn8::operator/=(int i)
|
|
{
|
|
ZZn t=(ZZn)1/i;
|
|
a*=t;
|
|
b*=t;
|
|
unitary=FALSE;
|
|
return *this;
|
|
}
|
|
|
|
ZZn8& ZZn8::operator/=(const ZZn8& x)
|
|
{
|
|
*this*=inverse(x);
|
|
if (!x.unitary) unitary=FALSE;
|
|
return *this;
|
|
}
|
|
|
|
ZZn8 inverse(const ZZn8& w)
|
|
{
|
|
ZZn8 y=conj(w);
|
|
if (w.unitary) return y;
|
|
ZZn4 u=w.a;
|
|
ZZn4 v=w.b;
|
|
u*=u;
|
|
v*=v;
|
|
u-=tx(v);
|
|
u=inverse(u);
|
|
y*=u;
|
|
return y;
|
|
}
|
|
|
|
ZZn8 operator+(const ZZn8& x,const ZZn8& y)
|
|
{ZZn8 w=x; w+=y; return w; }
|
|
|
|
ZZn8 operator+(const ZZn8& x,const ZZn4& y)
|
|
{ZZn8 w=x; w+=y; return w; }
|
|
|
|
ZZn8 operator+(const ZZn8& x,const ZZn& y)
|
|
{ZZn8 w=x; w+=y; return w; }
|
|
|
|
ZZn8 operator-(const ZZn8& x,const ZZn8& y)
|
|
{ZZn8 w=x; w-=y; return w; }
|
|
|
|
ZZn8 operator-(const ZZn8& x,const ZZn4& y)
|
|
{ZZn8 w=x; w-=y; return w; }
|
|
|
|
ZZn8 operator-(const ZZn8& x,const ZZn& y)
|
|
{ZZn8 w=x; w-=y; return w; }
|
|
|
|
ZZn8 operator-(const ZZn8& x)
|
|
{ZZn8 w; w.a=-x.a; w.b=-x.b; w.unitary=FALSE; return w; }
|
|
|
|
ZZn8 operator*(const ZZn8& x,const ZZn8& y)
|
|
{
|
|
ZZn8 w=x;
|
|
if (&x==&y) w*=w;
|
|
else w*=y;
|
|
return w;
|
|
}
|
|
|
|
ZZn8 operator*(const ZZn8& x,const ZZn4& y)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator*(const ZZn8& x,const ZZn& y)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator*(const ZZn4& y,const ZZn8& x)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator*(const ZZn& y,const ZZn8& x)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator*(const ZZn8& x,int y)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator*(int y,const ZZn8& x)
|
|
{ZZn8 w=x; w*=y; return w;}
|
|
|
|
ZZn8 operator/(const ZZn8& x,const ZZn8& y)
|
|
{ZZn8 w=x; w/=y; return w;}
|
|
|
|
ZZn8 operator/(const ZZn8& x,const ZZn4& y)
|
|
{ZZn8 w=x; w/=y; return w;}
|
|
|
|
ZZn8 operator/(const ZZn8& x,const ZZn& y)
|
|
{ZZn8 w=x; w/=y; return w;}
|
|
|
|
ZZn8 operator/(const ZZn8& x,int i)
|
|
{ZZn8 w=x; w/=i; return w;}
|
|
#ifndef MR_NO_RAND
|
|
ZZn8 randn8(void)
|
|
{ZZn8 w; w.a=randn4(); w.b=randn4(); w.unitary=FALSE; return w;}
|
|
#endif
|
|
|
|
|
|
ZZn8 rhs(const ZZn8& x)
|
|
{
|
|
ZZn8 w,A,B;
|
|
miracl *mip=get_mip();
|
|
int twist=mip->TWIST;
|
|
w=x*x*x;
|
|
A=(ZZn8)getA(); B=(ZZn8)getB();
|
|
if (twist)
|
|
{
|
|
if (twist==MR_QUARTIC_M)
|
|
{
|
|
w+=tx(A)*x;
|
|
}
|
|
if (twist==MR_QUARTIC_D)
|
|
{
|
|
w+=txd(A)*x;
|
|
}
|
|
if (twist==MR_SEXTIC_M)
|
|
{
|
|
w+=tx(B);
|
|
}
|
|
if (twist==MR_SEXTIC_D)
|
|
{
|
|
w+=txd(B);
|
|
}
|
|
if (twist==MR_QUADRATIC)
|
|
{
|
|
w+=tx(tx(A))*x+tx(tx(tx(B)));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
w+=A*x+B;
|
|
}
|
|
return w;
|
|
}
|
|
|
|
BOOL qr(const ZZn8& x)
|
|
{
|
|
ZZn4 a,s;
|
|
int qnr=get_mip()->qnr;
|
|
if (x.iszero()) return TRUE;
|
|
if (x.b.iszero()) return TRUE;
|
|
s=x.b; s*=s;
|
|
a=x.a; a*=a; a-=tx(s);
|
|
if (!qr(a)) return FALSE;
|
|
return TRUE;
|
|
/*
|
|
s=sqrt(a);
|
|
if (qr((x.a+s)/2) || qr((x.a-s)/2)) return TRUE;
|
|
return FALSE;
|
|
*/
|
|
}
|
|
|
|
ZZn8 sqrt(const ZZn8& x)
|
|
{
|
|
// sqrt(a+xb) = sqrt(a+sqrt(a*a-n*b*b)/2)+x.b/(2*sqrt(a+sqrt(a*a-n*b*b)/2))
|
|
// where x*x=n
|
|
|
|
ZZn8 w;
|
|
ZZn4 a,s;
|
|
if (x.iszero()) return w;
|
|
|
|
if (x.b.iszero())
|
|
{
|
|
a=x.a;
|
|
if (qr(a))
|
|
{
|
|
s=sqrt(a);
|
|
w.a=s; w.b=0;
|
|
}
|
|
else
|
|
{
|
|
s=sqrt(txd(a));
|
|
w.a=0; w.b=s;
|
|
}
|
|
return w;
|
|
}
|
|
|
|
s=x.b; s*=s;
|
|
a=x.a; a*=a; a-=tx(s);
|
|
|
|
s=sqrt(a);
|
|
if (s.iszero()) return w;
|
|
|
|
if (qr((x.a+s)/2))
|
|
{
|
|
a=sqrt((x.a+s)/2);
|
|
}
|
|
else
|
|
{
|
|
a=sqrt((x.a-s)/2);
|
|
if (a.iszero()) return w;
|
|
}
|
|
|
|
w.a=a;
|
|
w.b=x.b/(2*a);
|
|
|
|
return w;
|
|
}
|
|
|
|
ZZn8 conj(const ZZn8& x)
|
|
{
|
|
ZZn8 u=x;
|
|
u.conj();
|
|
return u;
|
|
}
|
|
|
|
ZZn8 tx(const ZZn8& x)
|
|
{
|
|
ZZn4 t=tx(x.b);
|
|
ZZn8 u(t,x.a);
|
|
return u;
|
|
}
|
|
|
|
ZZn8 txd(const ZZn8& x)
|
|
{
|
|
ZZn4 u,v;
|
|
x.get(u,v);
|
|
u=txd(u);
|
|
ZZn8 w(v,u);
|
|
|
|
return w;
|
|
}
|
|
|
|
ZZn8 tx2(const ZZn8& x)
|
|
{
|
|
ZZn8 u(tx(x.a),tx(x.b));
|
|
return u;
|
|
}
|
|
|
|
// regular ZZn8 powering - but see powl function in zzn4.h
|
|
|
|
ZZn8 pow(const ZZn8& x,const Big& k)
|
|
{
|
|
int i,j,nb,n,nbw,nzs;
|
|
ZZn8 u,u2,t[16];
|
|
if (k==0) return (ZZn8)1;
|
|
u=x;
|
|
if (k==1) return u;
|
|
//
|
|
// Prepare table for windowing
|
|
//
|
|
u2=(u*u);
|
|
t[0]=u;
|
|
|
|
for (i=1;i<16;i++)
|
|
t[i]=u2*t[i-1];
|
|
|
|
// Left to right method - with windows
|
|
|
|
nb=bits(k);
|
|
if (nb>1) for (i=nb-2;i>=0;)
|
|
{
|
|
n=window(k,i,&nbw,&nzs,5);
|
|
for (j=0;j<nbw;j++) u*=u;
|
|
if (n>0) u*=t[n/2];
|
|
i-=nbw;
|
|
if (nzs)
|
|
{
|
|
for (j=0;j<nzs;j++) u*=u;
|
|
i-=nzs;
|
|
}
|
|
}
|
|
return u;
|
|
}
|
|
|
|
// standard MIRACL multi-exponentiation
|
|
|
|
ZZn8 pow(int n,const ZZn8* x,const Big* b)
|
|
{
|
|
int k,j,i,m,nb,ea;
|
|
ZZn8 *G;
|
|
ZZn8 r;
|
|
m=1<<n;
|
|
G=new ZZn8[m];
|
|
|
|
for (i=0,k=1;i<n;i++)
|
|
{
|
|
for (j=0; j < (1<<i) ;j++)
|
|
{
|
|
if (j==0) G[k]=x[i];
|
|
else G[k]=G[j]*x[i];
|
|
k++;
|
|
}
|
|
}
|
|
|
|
nb=0;
|
|
for (j=0;j<n;j++)
|
|
if ((k=bits(b[j]))>nb) nb=k;
|
|
|
|
r=1;
|
|
for (i=nb-1;i>=0;i--)
|
|
{
|
|
ea=0;
|
|
k=1;
|
|
for (j=0;j<n;j++)
|
|
{
|
|
if (bit(b[j],i)) ea+=k;
|
|
k<<=1;
|
|
}
|
|
r*=r;
|
|
if (ea!=0) r*=G[ea];
|
|
}
|
|
delete [] G;
|
|
return r;
|
|
}
|
|
|
|
ZZn8 powl(const ZZn8& x,const Big& k)
|
|
{
|
|
ZZn8 w8,w9,two,y;
|
|
int i,nb;
|
|
|
|
two=(ZZn)2;
|
|
y=two*x;
|
|
if (k==0) return (ZZn8)two;
|
|
if (k==1) return y;
|
|
|
|
w8=two;
|
|
w9=y;
|
|
nb=bits(k);
|
|
for (i=nb-1;i>=0;i--)
|
|
{
|
|
if (bit(k,i))
|
|
{
|
|
w8*=w9; w8-=y; w9*=w9; w9-=two;
|
|
}
|
|
else
|
|
{
|
|
w9*=w8; w9-=y; w8*=w8; w8-=two;
|
|
}
|
|
}
|
|
return (w8/2);
|
|
}
|
|
|
|
#ifndef MR_NO_STANDARD_IO
|
|
|
|
ostream& operator<<(ostream& s,const ZZn8& xx)
|
|
{
|
|
ZZn8 b=xx;
|
|
ZZn4 x,y;
|
|
b.get(x,y);
|
|
s << "[" << x << "," << y << "]";
|
|
return s;
|
|
}
|
|
|
|
#endif
|
|
|