aboutsummaryrefslogtreecommitdiffstats
path: root/moon-abe/pbc-0.5.14/ecc/mnt.c
diff options
context:
space:
mode:
authorwukong <rebirthmonkey@gmail.com>2015-11-23 17:48:48 +0100
committerwukong <rebirthmonkey@gmail.com>2015-11-23 17:48:48 +0100
commitfca74d4bc3569506a6659880a89aa009dc11f552 (patch)
tree4cefd06af989608ea8ebd3bc6306889e2a1ad175 /moon-abe/pbc-0.5.14/ecc/mnt.c
parent840ac3ebca7af381132bf7e93c1e4c0430d6b16a (diff)
moon-abe cleanup
Change-Id: Ie1259856db03f0b9e80de3e967ec6bd1f03191b3
Diffstat (limited to 'moon-abe/pbc-0.5.14/ecc/mnt.c')
-rw-r--r--moon-abe/pbc-0.5.14/ecc/mnt.c496
1 files changed, 0 insertions, 496 deletions
diff --git a/moon-abe/pbc-0.5.14/ecc/mnt.c b/moon-abe/pbc-0.5.14/ecc/mnt.c
deleted file mode 100644
index 230442fc..00000000
--- a/moon-abe/pbc-0.5.14/ecc/mnt.c
+++ /dev/null
@@ -1,496 +0,0 @@
-// Routines for finding:
-// * MNT curves with embedding degree 6
-// * Freeman curves (which have embedding degree 10)
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h> // for intptr_t
-#include <gmp.h>
-#include "pbc_mnt.h"
-#include "pbc_memory.h"
-#include "pbc_utils.h"
-#include "misc/darray.h"
-
-struct pell_solution_s {
- int count;
- mpz_t minx; //minimal solution of x^2 - Dy^2 = 1
- mpz_t miny;
- mpz_t *x;
- mpz_t *y;
-};
-typedef struct pell_solution_s pell_solution_t[1];
-typedef struct pell_solution_s *pell_solution_ptr;
-
-static void freempz(void *data) {
- mpz_clear(data);
- pbc_free(data);
-}
-
-// Solves x^2 - Dy^2 = N where D not a square.
-// For square D, we have (x+Dy)(x-Dy) = N so we look at the factors of N.
-static void general_pell(pell_solution_t ps, mpz_t D, int N) {
- // TODO: Use brute force for small D.
- int i, sgnN = N > 0 ? 1 : -1;
- intptr_t f, n;
-
- // Find square factors of N.
- darray_t listf;
- darray_init(listf);
-
- f = 1;
- for (;;) {
- n = f * f;
- if (n > abs(N)) break;
- if (!(abs(N) % n)) {
- darray_append(listf, int_to_voidp(f));
- }
- f++;
- }
-
- //a0, twice_a0 don't change once initialized
- //a1 is a_i every iteration
- //P0, P1 become P_{i-1}, P_i every iteration
- //similarly for Q0, Q1
- mpz_t a0, twice_a0, a1;
- mpz_t P0, P1;
- mpz_t Q0, Q1;
- //variables to compute the convergents
- mpz_t p0, p1, pnext;
- mpz_t q0, q1, qnext;
-
- int d;
-
- darray_t listp, listq;
- mpz_ptr zptr;
-
- mpz_init(a0);
- mpz_init(twice_a0);
- mpz_init(a1);
- mpz_init(P0); mpz_init(P1);
- mpz_init(Q0); mpz_init(Q1);
- mpz_init(p0); mpz_init(p1); mpz_init(pnext);
- mpz_init(q0); mpz_init(q1); mpz_init(qnext);
-
- darray_init(listp);
- darray_init(listq);
-
- mpz_sqrt(a0, D);
- mpz_set_ui(P0, 0);
- mpz_set_ui(Q0, 1);
-
- mpz_set(P1, a0);
- mpz_mul(Q1, a0, a0);
- mpz_sub(Q1, D, Q1);
- mpz_add(a1, a0, P1);
- mpz_tdiv_q(a1, a1, Q1);
-
- mpz_add(twice_a0, a0, a0);
-
- mpz_set(p0, a0);
- mpz_set_ui(q0, 1);
- mpz_mul(p1, a0, a1);
- mpz_add_ui(p1, p1, 1);
- mpz_set(q1, a1);
-
- d = -1;
- for(;;) {
- if (d == sgnN) {
- for (i=0; i<listf->count; i++) {
- f = (intptr_t) listf->item[i];
- if (!mpz_cmp_ui(Q1, abs(N) / (f * f))) {
-//element_printf("found %Zd, %Zd, %d\n", p0, q0, f);
- zptr = (mpz_ptr) pbc_malloc(sizeof(mpz_t));
- mpz_init(zptr);
- mpz_set(zptr, p0);
- mpz_mul_ui(zptr, p0, f);
- darray_append(listp, zptr);
- zptr = (mpz_ptr) pbc_malloc(sizeof(mpz_t));
- mpz_init(zptr);
- mpz_set(zptr, q0);
- mpz_mul_ui(zptr, q0, f);
- darray_append(listq, zptr);
- }
- }
- }
-
- if (!mpz_cmp(twice_a0, a1) && d == 1) break;
- //compute more of the continued fraction expansion
- mpz_set(P0, P1);
- mpz_mul(P1, a1, Q1);
- mpz_sub(P1, P1, P0);
- mpz_set(Q0, Q1);
- mpz_mul(Q1, P1, P1);
- mpz_sub(Q1, D, Q1);
- mpz_divexact(Q1, Q1, Q0);
- mpz_add(a1, a0, P1);
- mpz_tdiv_q(a1, a1, Q1);
-
- //compute next convergent
- mpz_mul(pnext, a1, p1);
- mpz_add(pnext, pnext, p0);
- mpz_set(p0, p1);
- mpz_set(p1, pnext);
-
- mpz_mul(qnext, a1, q1);
- mpz_add(qnext, qnext, q0);
- mpz_set(q0, q1);
- mpz_set(q1, qnext);
- d = -d;
- }
- darray_clear(listf);
-
- mpz_init(ps->minx);
- mpz_init(ps->miny);
- mpz_set(ps->minx, p0);
- mpz_set(ps->miny, q0);
- n = listp->count;
- ps->count = n;
- if (n) {
- ps->x = (mpz_t *) pbc_malloc(sizeof(mpz_t) * n);
- ps->y = (mpz_t *) pbc_malloc(sizeof(mpz_t) * n);
- for (i = 0; i < n; i++) {
- mpz_init(ps->x[i]);
- mpz_init(ps->y[i]);
- mpz_set(ps->x[i], (mpz_ptr) listp->item[i]);
- mpz_set(ps->y[i], (mpz_ptr) listq->item[i]);
- }
- }
-
- mpz_clear(a0);
- mpz_clear(twice_a0);
- mpz_clear(a1);
- mpz_clear(P0); mpz_clear(P1);
- mpz_clear(Q0); mpz_clear(Q1);
- mpz_clear(p0); mpz_clear(p1); mpz_clear(pnext);
- mpz_clear(q0); mpz_clear(q1); mpz_clear(qnext);
-
- darray_forall(listp, freempz);
- darray_forall(listq, freempz);
- darray_clear(listp);
- darray_clear(listq);
-}
-
-static void pell_solution_clear(pell_solution_t ps) {
- int i, n = ps->count;
-
- if (n) {
- for (i=0; i<n; i++) {
- mpz_clear(ps->x[i]);
- mpz_clear(ps->y[i]);
- }
- pbc_free(ps->x);
- pbc_free(ps->y);
- }
- mpz_clear(ps->minx);
- mpz_clear(ps->miny);
-}
-
-void pbc_cm_init(pbc_cm_t cm) {
- mpz_init(cm->q);
- mpz_init(cm->r);
- mpz_init(cm->h);
- mpz_init(cm->n);
-}
-
-void pbc_cm_clear(pbc_cm_t cm) {
- mpz_clear(cm->q);
- mpz_clear(cm->r);
- mpz_clear(cm->h);
- mpz_clear(cm->n);
-}
-
-static int mnt_step2(int (*callback)(pbc_cm_t, void *), void *data,
- unsigned int D, mpz_t U) {
- int d;
- mpz_t n, l, q;
- mpz_t p;
- mpz_t r, cofac;
-
- mpz_init(l);
- mpz_mod_ui(l, U, 6);
- if (!mpz_cmp_ui(l, 1)) {
- mpz_sub_ui(l, U, 1);
- d = 1;
- } else if (!mpz_cmp_ui(l, 5)) {
- mpz_add_ui(l, U, 1);
- d = -1;
- } else {
- mpz_clear(l);
- return 0;
- }
-
- mpz_divexact_ui(l, l, 3);
- mpz_init(q);
-
- mpz_mul(q, l, l);
- mpz_add_ui(q, q, 1);
- if (!mpz_probab_prime_p(q, 10)) {
- mpz_clear(q);
- mpz_clear(l);
- return 0;
- }
-
- mpz_init(n);
- if (d < 0) {
- mpz_sub(n, q, l);
- } else {
- mpz_add(n, q, l);
- }
-
- mpz_init(p);
- mpz_init(r);
- mpz_init(cofac);
- {
- mpz_set_ui(cofac, 1);
- mpz_set(r, n);
- mpz_set_ui(p, 2);
- if (!mpz_probab_prime_p(r, 10)) for(;;) {
- if (mpz_divisible_p(r, p)) do {
- mpz_mul(cofac, cofac, p);
- mpz_divexact(r, r, p);
- } while (mpz_divisible_p(r, p));
- if (mpz_probab_prime_p(r, 10)) break;
- //TODO: use a table of primes instead?
- mpz_nextprime(p, p);
- if (mpz_sizeinbase(p, 2) > 16) {
- //printf("has 16+ bit factor\n");
- mpz_clear(r);
- mpz_clear(p);
- mpz_clear(cofac);
- mpz_clear(q);
- mpz_clear(l);
- mpz_clear(n);
- return 0;
- }
- }
- }
-
- pbc_cm_t cm;
- pbc_cm_init(cm);
- cm->k = 6;
- cm->D = D;
- mpz_set(cm->q, q);
- mpz_set(cm->r, r);
- mpz_set(cm->h, cofac);
- mpz_set(cm->n, n);
- int res = callback(cm, data);
- pbc_cm_clear(cm);
-
- mpz_clear(cofac);
- mpz_clear(r);
- mpz_clear(p);
- mpz_clear(q);
- mpz_clear(l);
- mpz_clear(n);
- return res;
-}
-
-int pbc_cm_search_d(int (*callback)(pbc_cm_t, void *), void *data,
- unsigned int D, unsigned int bitlimit) {
- mpz_t D3;
- mpz_t t0, t1, t2;
-
- mpz_init(D3);
- mpz_set_ui(D3, D * 3);
-
- if (mpz_perfect_square_p(D3)) {
- // The only squares that differ by 8 are 1 and 9,
- // which we get if U=V=1, D=3, but then l is not an integer.
- mpz_clear(D3);
- return 0;
- }
-
- mpz_init(t0);
- mpz_init(t1);
- mpz_init(t2);
-
- pell_solution_t ps;
- general_pell(ps, D3, -8);
-
- int i, n;
- int res = 0;
- n = ps->count;
- if (n) for (;;) {
- for (i=0; i<n; i++) {
- //element_printf("%Zd, %Zd\n", ps->x[i], ps->y[i]);
- res = mnt_step2(callback, data, D, ps->x[i]);
- if (res) goto toobig;
- //compute next solution as follows
- //if p, q is current solution
- //compute new solution p', q' via
- //(p + q sqrt{3D})(t + u sqrt{3D}) = p' + q' sqrt(3D)
- //where t, u is min. solution to Pell equation
- mpz_mul(t0, ps->minx, ps->x[i]);
- mpz_mul(t1, ps->miny, ps->y[i]);
- mpz_mul(t1, t1, D3);
- mpz_add(t0, t0, t1);
- if (2 * mpz_sizeinbase(t0, 2) > bitlimit + 10) goto toobig;
- mpz_mul(t2, ps->minx, ps->y[i]);
- mpz_mul(t1, ps->miny, ps->x[i]);
- mpz_add(t2, t2, t1);
- mpz_set(ps->x[i], t0);
- mpz_set(ps->y[i], t2);
- }
- }
-toobig:
-
- pell_solution_clear(ps);
- mpz_clear(t0);
- mpz_clear(t1);
- mpz_clear(t2);
- mpz_clear(D3);
- return res;
-}
-
-static int freeman_step2(int (*callback)(pbc_cm_t, void *), void *data,
- unsigned int D, mpz_t U) {
- mpz_t n, x, q;
- mpz_t p;
- mpz_t r, cofac;
- pbc_cm_t cm;
-
- mpz_init(x);
- mpz_mod_ui(x, U, 15);
- if (!mpz_cmp_ui(x, 5)) {
- mpz_sub_ui(x, U, 5);
- } else if (!mpz_cmp_ui(x, 10)) {
- mpz_add_ui(x, U, 5);
- } else {
- pbc_die("should never reach here");
- mpz_clear(x);
- return 0;
- }
-
- mpz_divexact_ui(x, x, 15);
- mpz_init(q);
- mpz_init(r);
-
- //q = 25x^4 + 25x^3 + 25x^2 + 10x + 3
- mpz_mul(r, x, x);
- mpz_add(q, x, x);
- mpz_mul_ui(r, r, 5);
- mpz_add(q, q, r);
- mpz_mul(r, r, x);
- mpz_add(q, q, r);
- mpz_mul(r, r, x);
- mpz_add(q, q, r);
- mpz_mul_ui(q, q, 5);
- mpz_add_ui(q, q, 3);
-
- if (!mpz_probab_prime_p(q, 10)) {
- mpz_clear(q);
- mpz_clear(r);
- mpz_clear(x);
- return 0;
- }
-
- //t = 10x^2 + 5x + 3
- //n = q - t + 1
- mpz_init(n);
-
- mpz_mul_ui(n, x, 5);
- mpz_mul(r, n, x);
- mpz_add(r, r, r);
- mpz_add(n, n, r);
- mpz_sub(n, q, n);
- mpz_sub_ui(n, n, 2);
-
- mpz_init(p);
- mpz_init(cofac);
- {
- mpz_set_ui(cofac, 1);
- mpz_set(r, n);
- mpz_set_ui(p, 2);
- if (!mpz_probab_prime_p(r, 10)) for(;;) {
- if (mpz_divisible_p(r, p)) do {
- mpz_mul(cofac, cofac, p);
- mpz_divexact(r, r, p);
- } while (mpz_divisible_p(r, p));
- if (mpz_probab_prime_p(r, 10)) break;
- //TODO: use a table of primes instead?
- mpz_nextprime(p, p);
- if (mpz_sizeinbase(p, 2) > 16) {
- //printf("has 16+ bit factor\n");
- mpz_clear(r);
- mpz_clear(p);
- mpz_clear(cofac);
- mpz_clear(q);
- mpz_clear(x);
- mpz_clear(n);
- return 0;
- }
- }
- }
-
- pbc_cm_init(cm);
- cm->k = 10;
- cm->D = D;
- mpz_set(cm->q, q);
- mpz_set(cm->r, r);
- mpz_set(cm->h, cofac);
- mpz_set(cm->n, n);
- int res = callback(cm, data);
- pbc_cm_clear(cm);
-
- mpz_clear(cofac);
- mpz_clear(r);
- mpz_clear(p);
- mpz_clear(q);
- mpz_clear(x);
- mpz_clear(n);
- return res;
-}
-
-int pbc_cm_search_g(int (*callback)(pbc_cm_t, void *), void *data,
- unsigned int D, unsigned int bitlimit) {
- int res = 0;
- mpz_t D15;
- mpz_t t0, t1, t2;
-
- mpz_init(D15);
- mpz_set_ui(D15, D);
- mpz_mul_ui(D15, D15, 15);
- if (mpz_perfect_square_p(D15)) {
- mpz_clear(D15);
- return 0;
- }
-
- mpz_init(t0);
- mpz_init(t1);
- mpz_init(t2);
-
- pell_solution_t ps;
- general_pell(ps, D15, -20);
-
- int i, n;
- n = ps->count;
- if (n) for (;;) {
- for (i=0; i<n; i++) {
- res = freeman_step2(callback, data, D, ps->x[i]);
- if (res) goto toobig;
- // Compute next solution as follows:
- // If p, q is current solution
- // then compute new solution p', q' via
- // (p + q sqrt{15D})(t + u sqrt{15D}) = p' + q' sqrt(15D)
- // where t, u is min. solution to Pell equation
- mpz_mul(t0, ps->minx, ps->x[i]);
- mpz_mul(t1, ps->miny, ps->y[i]);
- mpz_mul(t1, t1, D15);
- mpz_add(t0, t0, t1);
- if (2 * mpz_sizeinbase(t0, 2) > bitlimit + 10) goto toobig;
- mpz_mul(t2, ps->minx, ps->y[i]);
- mpz_mul(t1, ps->miny, ps->x[i]);
- mpz_add(t2, t2, t1);
- mpz_set(ps->x[i], t0);
- mpz_set(ps->y[i], t2);
- }
- }
-toobig:
-
- pell_solution_clear(ps);
- mpz_clear(t0);
- mpz_clear(t1);
- mpz_clear(t2);
- mpz_clear(D15);
- return res;
-}