X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/group-stdops.c diff --git a/group-stdops.c b/group-stdops.c deleted file mode 100644 index 77f48f7..0000000 --- a/group-stdops.c +++ /dev/null @@ -1,168 +0,0 @@ -/* -*-c-*- - * - * $Id$ - * - * Standard group operations - * - * (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 "group.h" -#include "pgen.h" - -/*----- Handy functions ---------------------------------------------------*/ - -/* --- @group_check@ --- * - * - * Arguments: @group *g@ = an abstract group - * @ge *x@ = a group element - * - * Returns: Zero on success, nonzero for failure. - * - * Use: Checks that @x@ is a valid group element. This may take a - * while, since it checks that %$x \ne 1$% and %$x^r = 1$%. - */ - -int group_check(group *g, ge *x) -{ - ge *d = G_CREATE(g); - int rc; - - G_EXP(g, d, x, g->r); - rc = (G_IDENTP(g, d) && !G_IDENTP(g, x)); - G_DESTROY(g, d); - if (!rc) return (-1); - return (0); -} - -/* --- @group_samep@ --- * - * - * Arguments: @group *g, *h@ = two abstract groups - * - * Returns: Nonzero if the groups are in fact identical (not just - * isomorphic). - * - * Use: Checks to see whether two groups are actually the same. This - * function does the full check: the group operatrion @samep@ - * just does the group-specific details. - */ - -int group_samep(group *g, group *h) -{ - return (g == h || (g->ops == h->ops && - MP_EQ(g->r, h->r) && MP_EQ(g->h, h->h) && - G_EQ(g, g->i, h->i) && G_EQ(g, g->g, h->g) && - G_SAMEP(g, h))); -} - -/*----- Standard implementations ------------------------------------------*/ - -/* --- @group_stdidentp@ --- * - * - * Arguments: @group *g@ = abstract group - * @ge *x@ = group element - * - * Returns: Nonzero if %$x$% is the group identity. - */ - -int group_stdidentp(group *g, ge *x) { return (G_EQ(g, x, g->i)); } - -/* --- @group_stdsqr@ --- * - * - * Arguments: @group *g@ = abstract group - * @ge *d@ = destination pointer - * @ge *x@ = group element - * - * Returns: --- - * - * Use: Computes %$d = x^2$% as %$d = x x$%. - */ - -void group_stdsqr(group *g, ge *d, ge *x) { G_MUL(g, d, x, x); } - -/* --- @group_stddiv@ --- * - * - * Arguments: @group *g@ = abstract group - * @ge *d@ = destination pointer - * @ge *x@ = dividend - * @ge *y@ = divisor - * - * Returns: --- - * - * Use: Computes %$d = x/y$% as %$d = x y^{-1}$%. - */ - -void group_stddiv(group *g, ge *d, ge *x, ge *y) - { G_INV(g, d, y); G_MUL(g, d, x, d); } - -/* --- @group_stdtoec@ --- * - * - * Arguments: @group *g@ = abstract group - * @ec *d@ = destination point - * @ge *x@ = group element - * - * Returns: @-1@, indicating failure. - * - * Use: Fails to convert a group element to an elliptic curve point. - */ - -int group_stdtoec(group *g, ec *d, ge *x) { return (-1); } - -/* --- @group_stdfromec@ --- * - * - * Arguments: @group *g@ = abstract group - * @ge *d@ = destination pointer - * @const ec *p@ = elliptic curve point - * - * Returns: Zero for success, @-1@ on failure. - * - * Use: Converts %$p$% to a group element by converting its %$x$%- - * coordinate. - */ - -int group_stdfromec(group *g, ge *d, const ec *p) - { if (EC_ATINF(p)) return (-1); return (G_FROMINT(g, d, p->x)); } - -/* --- @group_stdcheck@ --- * - * - * Arguments: @group *g@ = abstract group - * @grand *gr@ = random number source. - * - * Returns: Null on success, or a pointer to an error message. - */ - -const char *group_stdcheck(group *g, grand *gr) -{ - ge *t; - int rc; - - if (!pgen_primep(g->r, gr)) return ("group order not prime"); - t = G_CREATE(g); G_EXP(g, t, g->g, g->r); - rc = G_IDENTP(g, t); G_DESTROY(g, t); - if (!rc) return ("generator not in the group"); - return (0); -} - -/*----- That's all, folks -------------------------------------------------*/