void BaseOT::ByteArrayToPoint(EC2 *point, int field_size, BYTE* pBufIdx) {
int itmp;
Big bigtmp;
itmp = (int) (pBufIdx[0]);
bytes_to_big(field_size, (const char*) pBufIdx + 1, bigtmp.getbig());
*point = EC2(bigtmp, itmp);
}
void SamplePointFromBytes(EC2 *point, BYTE* input, int inbytelen) {
Big bigtmp;
bytes_to_big (inbytelen, (const char*) input, bigtmp.getbig());//(bigtmp, inbytelen, input);
premult(bigtmp.getbig(), MAXMSGSAMPLE, bigtmp.getbig());
for(int i = 0; i < MAXMSGSAMPLE; i++)
{
*point = EC2(bigtmp, 0);
if(!point_at_infinity(point->get_point()))
return;
*point = EC2(bigtmp, 1);
if(!point_at_infinity(point->get_point()))
return;
incr(bigtmp.getbig(), 1, bigtmp.getbig());
}
cerr << "Error while sampling point, exiting!" << endl;
exit(0);
}
void BaseOT::SampleRandomPoint(EC2 *point, int field_size) {
Big bigtmp;
int itmp = rand()%2;
do
{
bigtmp = rand(field_size, 2);
*point = EC2(bigtmp, itmp);
}
while (point_at_infinity(point->get_point()));
}
void SampleRandomPoint(EC2 &point, fparams* params) {
Big bigtmp;
int itmp = rand()%2;
do
{
bigtmp = rand(params->secparam, 2);
point = EC2(bigtmp, itmp);
}
while (point_at_infinity(point.get_point()));
}
void BaseOT::Miracl_InitPoint(EC2* point, Big x, Big y)
{
*point = EC2(x, y);
}
void MiraclInitPoint(EC2& point, Big x, Big y)
{
point = EC2(x, y);
}
int main()
{
ifstream common("common2.ecs"); /* construct file I/O streams */
ifstream private_key("private.ecs");
ifstream message;
ofstream signature;
char ifname[13],ofname[13];
EC2 G;
Big a2,a6,q,x,y,h,r,s,d,k;
long seed;
int m,a,b,c,cf;
miracl *mip=&precision;
/* randomise */
cout << "Enter 9 digit random number seed = ";
cin >> seed;
irand(seed);
/* get common data */
common >> m;
mip->IOBASE=16;
common >> a2 >> a6 >> q >> x >> y;
mip->IOBASE=10;
common >> a >> b >> c;
/* calculate r - this can be done off-line,
and hence amortized to almost nothing */
ecurve2(m,a,b,c,a2,a6,FALSE,MR_PROJECTIVE);
G=EC2(x,y);
k=rand(q);
G*=k; /* see brick.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|ios::nocreate);
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);
mip->IOBASE=10;
signature << r << endl;
signature << s << endl;
return 0;
}