+++ /dev/null
-/* -*-c-*-
- *
- * $Id$
- *
- * Abstraction for prime groups
- *
- * (c) 2004 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb 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 Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <mLib/sub.h>
-
-#include "mpmont.h"
-#include "pgen.h"
-
-#define ge mp *
-#include "group.h"
-#include "group-guts.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- Group operations --- */
-
-static void gdestroygroup(group *gg) {
- gctx_prime *g = (gctx_prime *)gg;
- mp_drop(g->gen); mp_drop(g->g.r); mp_drop(g->g.h);
- mpmont_destroy(&g->mm);
- DESTROY(g);
-}
-
-static mp **gcreate(group *gg)
- { mp **x = CREATE(mp *); *x = MP_COPY(*gg->i); return (x); }
-
-static void gcopy(group *gg, mp **d, mp **x)
- { mp *t = MP_COPY(*x); MP_DROP(*d); *d = t; }
-
-static void gburn(group *gg, mp **x) { (*x)->f |= MP_BURN; }
-
-static void gdestroy(group *gg, mp **x) { MP_DROP(*x); DESTROY(x); }
-
-static int gsamep(group *gg, group *hh) {
- gctx_prime *g = (gctx_prime *)gg, *h = (gctx_prime *)hh;
- return (MP_EQ(g->mm.m, h->mm.m));
-}
-
-static int geq(group *gg, mp **x, mp **y) { return (MP_EQ(*x, *y)); }
-
-static const char *gcheck(group *gg, grand *gr) {
- gctx_prime *g = (gctx_prime *)gg; int rc; mp *t;
- if (!pgen_primep(g->mm.m, gr)) return ("p is not prime");
- t = mp_mul(MP_NEW, g->g.r, g->g.h); t = mp_add(t, t, MP_ONE);
- rc = MP_EQ(t, g->mm.m); MP_DROP(t); if (!rc) return ("not a subgroup");
- return (group_stdcheck(gg, gr));
-}
-
-static void gmul(group *gg, mp **d, mp **x, mp **y)
- { gctx_prime *g = (gctx_prime *)gg; *d = mpmont_mul(&g->mm, *d, *x, *y); }
-
-static void gsqr(group *gg, mp **d, mp **x) {
- gctx_prime *g = (gctx_prime *)gg; mp *r = mp_sqr(*d, *x);
- *d = mpmont_reduce(&g->mm, r, r);
-}
-
-static void ginv(group *gg, mp **d, mp **x) {
- gctx_prime *g = (gctx_prime *)gg; mp *r = mpmont_reduce(&g->mm, *d, *x);
- r = mp_modinv(r, r, g->mm.m); *d = mpmont_mul(&g->mm, r, r, g->mm.r2);
-}
-
-static void gexp(group *gg, mp **d, mp **x, mp *n)
- { gctx_prime *g = (gctx_prime *)gg; *d = mpmont_expr(&g->mm, *d, *x, n); }
-
-static void gmexp(group *gg, mp **d, const group_expfactor *f, size_t n) {
- gctx_prime *g = (gctx_prime *)gg; size_t i;
- mp_expfactor *ff = xmalloc(n * sizeof(mp_expfactor));
- for (i = 0; i < n; i++) { ff[i].base = *f[i].base; ff[i].exp = f[i].exp; }
- *d = mpmont_mexpr(&g->mm, *d, ff, n); xfree(ff);
-}
-
-static int gread(group *gg, mp **d, const mptext_ops *ops, void *p) {
- gctx_prime *g = (gctx_prime *)gg; mp *t;
- if ((t = mp_read(MP_NEW, 0, ops, p)) == 0) return (-1);
- mp_drop(*d); *d = mpmont_mul(&g->mm, t, t, g->mm.r2); return (0);
-}
-
-static int gwrite(group *gg, mp **x, const mptext_ops *ops, void *p) {
- gctx_prime *g = (gctx_prime *)gg;
- mp *t = mpmont_reduce(&g->mm, MP_NEW, *x);
- int rc = mp_write(t, 10, ops, p); MP_DROP(t); return (rc);
-}
-
-static mp *gtoint(group *gg, mp *d, mp **x) {
- gctx_prime *g = (gctx_prime *)gg;
- return (mpmont_reduce(&g->mm, d, *x));
-}
-
-static int gfromint(group *gg, mp **d, mp *x) {
- gctx_prime *g = (gctx_prime *)gg; mp_div(0, d, x, g->mm.m);
- *d = mpmont_mul(&g->mm, *d, *d, g->mm.r2); return (0);
-}
-
-static int gtobuf(group *gg, buf *b, mp **x) {
- gctx_prime *g = (gctx_prime *)gg;
- mp *t = mpmont_reduce(&g->mm, MP_NEW, *x);
- int rc = buf_putmp(b, t); MP_DROP(t); return (rc);
-}
-
-static int gfrombuf(group *gg, buf *b, mp **d) {
- gctx_prime * g = (gctx_prime *)gg; mp *x;
- if ((x = buf_getmp(b)) == 0) return (-1);
- mp_div(0, &x, x, g->mm.m); mp_drop(*d);
- *d = mpmont_mul(&g->mm, x, x, g->mm.r2); return(0);
-}
-
-static int gtoraw(group *gg, buf *b, mp **x) {
- gctx_prime *g = (gctx_prime *)gg; octet *q;
- mp *t = mpmont_reduce(&g->mm, MP_NEW, *x);
- if ((q = buf_get(b, g->g.noctets)) == 0) { MP_DROP(t); return (-1); }
- mp_storeb(t, q, g->g.noctets); MP_DROP(t); return (0);
-}
-
-static int gfromraw(group *gg, buf *b, mp **d) {
- gctx_prime * g = (gctx_prime *)gg; mp *x; octet *q;
- if ((q = buf_get(b, g->g.noctets)) == 0) return (-1);
- x = mp_loadb(MP_NEW, q, g->g.noctets);
- mp_div(0, &x, x, g->mm.m); mp_drop(*d);
- *d = mpmont_mul(&g->mm, x, x, g->mm.r2); return(0);
-}
-
-/* --- @group_prime@ --- *
- *
- * Arguments: @const gprime_param *gp@ = group parameters
- *
- * Returns: A pointer to the group, or null.
- *
- * Use: Constructs an abstract group interface for a subgroup of a
- * prime field. Group elements are @mp *@ pointers.
- */
-
-static const group_ops gops = {
- GTY_PRIME, "prime",
- gdestroygroup, gcreate, gcopy, gburn, gdestroy,
- gsamep, geq, group_stdidentp,
- gcheck,
- gmul, gsqr, ginv, group_stddiv, gexp, gmexp,
- gread, gwrite,
- gtoint, gfromint, group_stdtoec, group_stdfromec, gtobuf, gfrombuf,
- gtoraw, gfromraw
-};
-
-group *group_prime(const gprime_param *gp)
-{
- gctx_prime *g;
-
- if (!MP_POSP(gp->p) || !MP_ODDP(gp->p))
- return (0);
- g = CREATE(gctx_prime);
- g->g.ops = &gops;
- g->g.nbits = mp_bits(gp->p);
- g->g.noctets = (g->g.nbits + 7) >> 3;
- mpmont_create(&g->mm, gp->p);
- g->g.i = &g->mm.r;
- g->gen = mpmont_mul(&g->mm, MP_NEW, gp->g, g->mm.r2);
- g->g.g = &g->gen;
- g->g.r = MP_COPY(gp->q);
- g->g.h = MP_NEW; mp_div(&g->g.h, 0, gp->p, gp->q);
- return (&g->g);
-}
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff