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/*
* ecgen, tool for generating Elliptic curve domain parameters
* Copyright (C) 2017 J08nY
*/
#include "field.h"
#include "poly.h"
#include "random.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);
}
}
int field_random(curve_t *curve, config_t *config, ...) {
switch (config->field) {
case FIELD_PRIME:
curve->field = field_primer(config->bits);
return 1;
case FIELD_BINARY:
curve->field = field_binaryr(config->bits);
return 1;
default:
return 0; /* NOT REACHABLE */
}
}
int field_input(curve_t *curve, config_t *config, ...) {
return -1; // NOT IMPLEMENTED
}
GEN field_params(GEN field) {
pari_sp ltop = avma;
if (typ(field) == t_INT) {
GEN p3 = cgetg(2, t_VEC);
gel(p3, 1) = gcopy(field);
return gerepilecopy(ltop, p3);
}
GEN out = gtovec0(gen_0, 3);
long j = 1;
long l2 = glength(member_mod(field)) - 2;
{
pari_sp btop = avma;
for (long i = 0; i <= l2; ++i) {
GEN c = polcoeff0(member_mod(field), i, -1);
if (cmpis(c, 0) != 0) {
gel(out, j) = stoi(i);
j++;
}
if (gc_needed(btop, 1)) gerepileall(btop, 3, &out, &c);
}
}
return gerepilecopy(ltop, 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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