Commit | Line | Data |
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34e4f738 | 1 | /* -*-c-*- |
2 | * | |
34e4f738 | 3 | * Abstraction for elliptic curve groups |
4 | * | |
5 | * (c) 2004 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
34e4f738 | 9 | * |
10 | * This file is part of Catacomb. | |
11 | * | |
12 | * Catacomb is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU Library General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
45c0fd36 | 16 | * |
34e4f738 | 17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU Library General Public License for more details. | |
45c0fd36 | 21 | * |
34e4f738 | 22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free | |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
25 | * MA 02111-1307, USA. | |
26 | */ | |
27 | ||
34e4f738 | 28 | /*----- Header files ------------------------------------------------------*/ |
29 | ||
30 | #include <ctype.h> | |
31 | ||
141c1284 | 32 | #include <mLib/macros.h> |
34e4f738 | 33 | #include <mLib/sub.h> |
34 | ||
35 | #define ge ec | |
0f3faccd | 36 | #include "ec-raw.h" |
f94b972d | 37 | #include "group-guts.h" |
34e4f738 | 38 | |
39 | /*----- Main code ---------------------------------------------------------*/ | |
40 | ||
41 | /* --- Group operations --- */ | |
42 | ||
43 | static void gdestroygroup(group *gg) { | |
f94b972d | 44 | gctx_ec *g = (gctx_ec *)gg; |
34e4f738 | 45 | EC_DESTROY(&g->gen); |
46 | ec_freeinfo(&g->ei); | |
47 | DESTROY(g); | |
48 | } | |
49 | ||
50 | static ec *gcreate(group *gg) | |
51 | { ec *x = CREATE(ec); EC_CREATE(x); return (x); } | |
52 | ||
53 | static void gcopy(group *gg, ec *d, ec *x) { EC_COPY(d, x); } | |
54 | ||
55 | static void gburn(group *gg, ec *x) { if (x->x) (x->x)->f |= MP_BURN; } | |
56 | ||
57 | static void gdestroy(group *gg, ec *x) { EC_DESTROY(x); DESTROY(x); } | |
58 | ||
59 | static int gsamep(group *gg, group *hh) { | |
f94b972d | 60 | gctx_ec *g = (gctx_ec *)gg, *h = (gctx_ec *)hh; |
34e4f738 | 61 | return (ec_sameinfop(&g->ei, &h->ei)); |
62 | } | |
63 | ||
64 | static int geq(group *gg, ec *x, ec *y) { | |
f94b972d | 65 | gctx_ec *g = (gctx_ec *)gg; EC_FIX(g->ei.c, x, x); EC_FIX(g->ei.c, y, y); |
34e4f738 | 66 | return (EC_EQ(x, y)); |
67 | } | |
68 | ||
69 | static int gidentp(group *gg, ec *x) { return (EC_ATINF(x)); } | |
70 | ||
71 | static const char *gcheck(group *gg, grand *gr) | |
f94b972d | 72 | { gctx_ec *g = (gctx_ec *)gg; return (ec_checkinfo(&g->ei, gr)); } |
34e4f738 | 73 | |
74 | static void gmul(group *gg, ec *d, ec *x, ec *y) | |
f94b972d | 75 | { gctx_ec *g = (gctx_ec *)gg; EC_ADD(g->ei.c, d, x, y); } |
34e4f738 | 76 | |
77 | static void gsqr(group *gg, ec *d, ec *x) | |
f94b972d | 78 | { gctx_ec *g = (gctx_ec *)gg; EC_DBL(g->ei.c, d, x); } |
34e4f738 | 79 | |
80 | static void ginv(group *gg, ec *d, ec *x) | |
f94b972d | 81 | { gctx_ec *g = (gctx_ec *)gg; EC_NEG(g->ei.c, d, x); } |
34e4f738 | 82 | |
83 | static void gdiv(group *gg, ec *d, ec *x, ec *y) | |
f94b972d | 84 | { gctx_ec *g = (gctx_ec *)gg; EC_SUB(g->ei.c, d, x, y); } |
34e4f738 | 85 | |
86 | static void gexp(group *gg, ec *d, ec *x, mp *n) | |
f94b972d | 87 | { gctx_ec *g = (gctx_ec *)gg; ec_imul(g->ei.c, d, x, n); } |
34e4f738 | 88 | |
89 | static void gmexp(group *gg, ec *d, const group_expfactor *f, size_t n) { | |
f94b972d | 90 | gctx_ec *g = (gctx_ec *)gg; size_t i; |
45c0fd36 | 91 | ec_mulfactor *ff = xmalloc(n * sizeof(ec_mulfactor)); |
34e4f738 | 92 | for (i = 0; i < n; i++) { ff[i].base = *f[i].base; ff[i].exp = f[i].exp; } |
93 | ec_immul(g->ei.c, d, ff, n); xfree(ff); | |
94 | } | |
95 | ||
96 | static int gread(group *gg, ec *d, const mptext_ops *ops, void *p) { | |
f94b972d | 97 | gctx_ec *g = (gctx_ec *)gg; |
34e4f738 | 98 | ec t = EC_INIT; |
99 | int rc = -1; | |
100 | int ch; | |
101 | ||
102 | ch = ops->get(p); | |
141c1284 MW |
103 | if (TOLOWER(ch) == 'i') { |
104 | if (TOLOWER(ops->get(p)) != 'n' || TOLOWER(ops->get(p)) != 'f') | |
34e4f738 | 105 | return (-1); |
106 | EC_SETINF(d); | |
107 | return (0); | |
108 | } | |
109 | ops->unget(ch, p); | |
110 | if ((t.x = mp_read(MP_NEW, 0, ops, p)) == 0) goto done; | |
141c1284 | 111 | do ch = ops->get(p); while (ch == ',' || ISSPACE(ch)); ops->unget(ch, p); |
34e4f738 | 112 | if ((t.y = mp_read(MP_NEW, 0, ops, p)) == 0) goto done; |
113 | EC_IN(g->ei.c, &t, &t); | |
114 | if (EC_CHECK(g->ei.c, &t)) goto done; | |
115 | EC_COPY(d, &t); rc = 0; | |
116 | EC_DESTROY(&t); | |
117 | done: | |
118 | return (rc); | |
119 | } | |
120 | ||
121 | static int gwrite(group *gg, ec *x, const mptext_ops *ops, void *p) { | |
f94b972d | 122 | gctx_ec *g = (gctx_ec *)gg; int rc = -1; ec t = EC_INIT; |
123 | EC_OUT(g->ei.c, &t, x); if (EC_ATINF(&t)) rc = ops->put("inf", 3, p); | |
34e4f738 | 124 | else if (!ops->put("0x", 2, p) && !mp_write(t.x, 16, ops, p) && |
125 | !ops->put(", 0x", 4, p) && !mp_write(t.y, 16, ops, p)) rc = 0; | |
126 | EC_DESTROY(&t); return (rc); | |
127 | } | |
128 | ||
129 | static mp *gtoint(group *gg, mp *d, ec *x) { | |
f94b972d | 130 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; mp *i; if (EC_ATINF(x)) i = 0; |
34e4f738 | 131 | else { EC_OUT(g->ei.c, &t, x); i = MP_COPY(t.x); EC_DESTROY(&t); } |
132 | mp_drop(d); return (i); | |
133 | } | |
134 | ||
135 | static int gfromint(group *gg, ec *d, mp *x) { | |
f94b972d | 136 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; |
34e4f738 | 137 | if (!ec_find(g->ei.c, &t, x)) return (-1); |
138 | EC_IN(g->ei.c, d, &t); EC_DESTROY(&t); return (0); | |
139 | } | |
140 | ||
141 | static int gtoec(group *gg, ec *d, ec *x) | |
f94b972d | 142 | { gctx_ec *g = (gctx_ec *)gg; EC_OUT(g->ei.c, d, x); return (0); } |
34e4f738 | 143 | |
5c3f75ec | 144 | static int gfromec(group *gg, ec *d, const ec *x) { |
f94b972d | 145 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; int rc; EC_IN(g->ei.c, &t, x); |
34e4f738 | 146 | rc = EC_CHECK(g->ei.c, &t); if (!rc) EC_COPY(d, &t); EC_DESTROY(&t); |
147 | return (rc); | |
148 | } | |
45c0fd36 | 149 | |
34e4f738 | 150 | static int gtobuf(group *gg, buf *b, ec *x) { |
f94b972d | 151 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; int rc; |
34e4f738 | 152 | EC_OUT(g->ei.c, &t, x); rc = buf_putec(b, &t); EC_DESTROY(&t); return (rc); |
153 | } | |
154 | ||
155 | static int gfrombuf(group *gg, buf *b, ec *d) { | |
f94b972d | 156 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; int rc; |
34e4f738 | 157 | if (buf_getec(b, &t)) return (-1); |
158 | EC_IN(g->ei.c, &t, &t); rc = EC_CHECK(g->ei.c, &t); | |
159 | if (!rc) EC_COPY(d, &t); EC_DESTROY(&t); return (rc); | |
160 | } | |
161 | ||
0f3faccd | 162 | static int gtoraw(group *gg, buf *b, ec *x) { |
f94b972d | 163 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; int rc; |
0f3faccd | 164 | EC_OUT(g->ei.c, &t, x); rc = ec_putraw(g->ei.c, b, &t); |
165 | EC_DESTROY(&t); return (rc); | |
166 | } | |
167 | ||
168 | static int gfromraw(group *gg, buf *b, ec *d) { | |
f94b972d | 169 | gctx_ec *g = (gctx_ec *)gg; ec t = EC_INIT; int rc; |
0f3faccd | 170 | if (ec_getraw(g->ei.c, b, &t)) return (-1); |
171 | EC_IN(g->ei.c, &t, &t); rc = EC_CHECK(g->ei.c, &t); | |
172 | if (!rc) EC_COPY(d, &t); EC_DESTROY(&t); return (rc); | |
173 | } | |
174 | ||
34e4f738 | 175 | /* --- @group_ec@ --- * |
176 | * | |
177 | * Arguments: @const ec_info *ei@ = elliptic curve parameters | |
178 | * | |
179 | * Returns: A pointer to the group. | |
180 | * | |
181 | * Use: Constructs an abstract group interface for an elliptic curve | |
182 | * group. Group elements are @ec@ structures. The contents of | |
183 | * the @ec_info@ structure becomes the property of the @group@ | |
184 | * object; you can (and should) free the structure itself, but | |
185 | * calling @ec_freeinfo@ on it is not allowed. | |
186 | */ | |
187 | ||
188 | static const group_ops gops = { | |
f94b972d | 189 | GTY_EC, "ec", |
34e4f738 | 190 | gdestroygroup, gcreate, gcopy, gburn, gdestroy, |
191 | gsamep, geq, gidentp, | |
192 | gcheck, | |
193 | gmul, gsqr, ginv, gdiv, gexp, gmexp, | |
194 | gread, gwrite, | |
0f3faccd | 195 | gtoint, gfromint, gtoec, gfromec, gtobuf, gfrombuf, gtoraw, gfromraw |
34e4f738 | 196 | }; |
197 | ||
198 | group *group_ec(const ec_info *ei) | |
199 | { | |
f94b972d | 200 | gctx_ec *g = CREATE(gctx_ec); |
34e4f738 | 201 | |
202 | g->g.ops = &gops; | |
203 | g->g.nbits = ei->c->f->nbits * 2; | |
0f3faccd | 204 | g->g.noctets = ei->c->f->noctets * 2 + 1; |
34e4f738 | 205 | g->ei = *ei; |
206 | EC_CREATE(&g->id); | |
207 | g->g.i = &g->id; | |
208 | EC_CREATE(&g->gen); | |
02d7884d | 209 | g->g.g = &g->gen; |
34e4f738 | 210 | EC_IN(g->ei.c, &g->gen, &ei->g); |
211 | g->g.r = ei->r; | |
212 | g->g.h = ei->h; | |
213 | return (&g->g); | |
214 | } | |
215 | ||
216 | /*----- That's all, folks -------------------------------------------------*/ |