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/*
* ecgen, tool for generating Elliptic curve domain parameters
* Copyright (C) 2017 J08nY
*/
#include "field.h"
GEN field_primer(long bits) {
return random_prime(bits);
}
GEN field_binaryr(long bits) {
if (poly_exists(bits)) {
return poly_find_gen(bits);
} else {
fprintf(stderr, "Unable to find a suitable binary field. Use an explicit one.");
exit(1);
}
}
GEN field_params(GEN field) {
pari_sp ltop = avma;
long l2;
if (typ(field) == t_INT) {
GEN p3 = cgetg(2, t_VEC);
gel(p3, 1) = gcopy(field);
p3 = gerepilecopy(ltop, p3);
return p3;
}
GEN out = gtovec0(gen_0, 3);
long j = 1;
l2 = glength(member_mod(field)) - 2;
{
pari_sp btop = avma;
for (GEN i = gen_1; gcmpgs(i, l2) <= 0; i = gaddgs(i, 1)) {
GEN c = polcoeff0(member_mod(field), gtos(i), -1);
if (cmpis(c, 0) != 0) {
gel(out, j) = gcopy(i);
j++;
}
if (gc_needed(btop, 1)) gerepileall(btop, 4, &out, &c, &i);
}
}
out = gerepilecopy(ltop, out);
return out;
}
GEN field_elementi(GEN element) {
switch (typ(element)) {
case t_INT:
return element;
case t_INTMOD:
return lift(element);
case t_FFELT: {
pari_sp ltop = avma;
GEN coeffs = FF_to_FpXQ(element);
GEN vec = gtovec(coeffs);
GEN n = fromdigits(vec, stoi(2));
return gerepilecopy(ltop, n);
}
default:
pari_err_TYPE("field_elementi", element);
return NULL; /* NOT REACHABLE */
}
}
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