Commit | Line | Data |
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5c3f75ec | 1 | /* -*-c-*- |
5c3f75ec | 2 | * |
3 | * Catcrypt key-encapsulation | |
4 | * | |
5 | * (c) 2004 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
5c3f75ec | 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 | * |
5c3f75ec | 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 | * |
5c3f75ec | 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 | ||
28 | /*----- Header files ------------------------------------------------------*/ | |
29 | ||
cd6eca43 MW |
30 | #define _FILE_OFFSET_BITS 64 |
31 | ||
5c3f75ec | 32 | #include <stdlib.h> |
33 | ||
34 | #include <mLib/alloc.h> | |
35 | #include <mLib/dstr.h> | |
36 | #include <mLib/report.h> | |
37 | #include <mLib/sub.h> | |
38 | ||
39 | #include "mprand.h" | |
40 | #include "rand.h" | |
41 | ||
42 | #include "ec.h" | |
43 | #include "ec-keys.h" | |
44 | #include "dh.h" | |
45 | #include "rsa.h" | |
46 | ||
47 | #include "rmd160.h" | |
48 | #include "blowfish-cbc.h" | |
49 | ||
50 | #include "cc.h" | |
51 | ||
52 | /*----- Key encapsulation -------------------------------------------------*/ | |
53 | ||
54 | /* --- RSA --- */ | |
55 | ||
56 | typedef struct rsa_encctx { | |
57 | kem k; | |
58 | rsa_pubctx rp; | |
59 | } rsa_encctx; | |
60 | ||
61 | static kem *rsa_encinit(key *k, void *kd) | |
62 | { | |
63 | rsa_encctx *re = CREATE(rsa_encctx); | |
64 | rsa_pubcreate(&re->rp, kd); | |
65 | return (&re->k); | |
66 | } | |
67 | ||
68 | static int rsa_encdoit(kem *k, dstr *d, ghash *h) | |
69 | { | |
70 | rsa_encctx *re = (rsa_encctx *)k; | |
71 | mp *x = mprand_range(MP_NEW, re->rp.rp->n, &rand_global, 0); | |
72 | mp *y = rsa_pubop(&re->rp, MP_NEW, x); | |
73 | size_t n = mp_octets(re->rp.rp->n); | |
74 | dstr_ensure(d, n); | |
75 | mp_storeb(x, d->buf, n); | |
76 | GH_HASH(h, d->buf, n); | |
77 | mp_storeb(y, d->buf, n); | |
78 | d->len += n; | |
79 | mp_drop(x); | |
80 | mp_drop(y); | |
81 | return (0); | |
82 | } | |
83 | ||
84 | static const char *rsa_lengthcheck(mp *n) | |
85 | { | |
86 | if (mp_bits(n) < 1020) return ("key too short"); | |
87 | return (0); | |
88 | } | |
89 | ||
90 | static const char *rsa_enccheck(kem *k) | |
91 | { | |
92 | rsa_encctx *re = (rsa_encctx *)k; | |
93 | const char *e; | |
94 | if ((e = rsa_lengthcheck(re->rp.rp->n)) != 0) return (e); | |
95 | return (0); | |
96 | } | |
97 | ||
98 | static void rsa_encdestroy(kem *k) | |
99 | { | |
100 | rsa_encctx *re = (rsa_encctx *)k; | |
101 | rsa_pubdestroy(&re->rp); | |
102 | DESTROY(re); | |
103 | } | |
104 | ||
105 | static const kemops rsa_encops = { | |
106 | rsa_pubfetch, sizeof(rsa_pub), | |
107 | rsa_encinit, rsa_encdoit, rsa_enccheck, rsa_encdestroy | |
108 | }; | |
109 | ||
110 | typedef struct rsa_decctx { | |
111 | kem k; | |
112 | rsa_privctx rp; | |
113 | } rsa_decctx; | |
114 | ||
115 | static kem *rsa_decinit(key *k, void *kd) | |
116 | { | |
117 | rsa_decctx *rd = CREATE(rsa_decctx); | |
118 | rsa_privcreate(&rd->rp, kd, &rand_global); | |
119 | return (&rd->k); | |
120 | } | |
121 | ||
122 | static int rsa_decdoit(kem *k, dstr *d, ghash *h) | |
123 | { | |
124 | rsa_decctx *rd = (rsa_decctx *)k; | |
125 | mp *x = mp_loadb(MP_NEW, d->buf, d->len); | |
126 | size_t n; | |
127 | char *p; | |
128 | ||
129 | if (MP_CMP(x, >=, rd->rp.rp->n)) { | |
130 | mp_drop(x); | |
131 | return (-1); | |
132 | } | |
133 | n = mp_octets(rd->rp.rp->n); | |
134 | p = xmalloc(n); | |
135 | x = rsa_privop(&rd->rp, x, x); | |
136 | mp_storeb(x, p, n); | |
137 | GH_HASH(h, p, n); | |
138 | mp_drop(x); | |
139 | xfree(p); | |
140 | return (0); | |
141 | } | |
142 | ||
143 | static const char *rsa_deccheck(kem *k) | |
144 | { | |
145 | rsa_decctx *rd = (rsa_decctx *)k; | |
146 | const char *e; | |
147 | if ((e = rsa_lengthcheck(rd->rp.rp->n)) != 0) return (e); | |
148 | return (0); | |
149 | } | |
150 | ||
151 | static void rsa_decdestroy(kem *k) | |
152 | { | |
153 | rsa_decctx *rd = (rsa_decctx *)k; | |
154 | rsa_privdestroy(&rd->rp); | |
155 | DESTROY(rd); | |
156 | } | |
157 | ||
158 | static const kemops rsa_decops = { | |
159 | rsa_privfetch, sizeof(rsa_priv), | |
160 | rsa_decinit, rsa_decdoit, rsa_deccheck, rsa_decdestroy | |
161 | }; | |
162 | ||
163 | /* --- DH and EC --- */ | |
164 | ||
165 | typedef struct dh_encctx { | |
166 | kem k; | |
167 | group *g; | |
168 | mp *x; | |
169 | ge *y; | |
170 | } dh_encctx; | |
171 | ||
45c0fd36 | 172 | static dh_encctx *dh_doinit(key *k, const gprime_param *gp, mp *y, |
3688eb75 | 173 | group *(*makegroup)(const gprime_param *), |
174 | const char *what) | |
5c3f75ec | 175 | { |
176 | dh_encctx *de = CREATE(dh_encctx); | |
177 | dstr t = DSTR_INIT; | |
178 | ||
179 | key_fulltag(k, &t); | |
3688eb75 | 180 | if ((de->g = makegroup(gp)) == 0) |
181 | die(EXIT_FAILURE, "bad %s group in key `%s'", what, t.buf); | |
5c3f75ec | 182 | de->x = MP_NEW; |
183 | de->y = G_CREATE(de->g); | |
184 | if (G_FROMINT(de->g, de->y, y)) | |
185 | die(EXIT_FAILURE, "bad public key `%s'", t.buf); | |
186 | dstr_destroy(&t); | |
187 | return (de); | |
188 | } | |
189 | ||
190 | static dh_encctx *ec_doinit(key *k, const char *cstr, const ec *y) | |
191 | { | |
192 | dh_encctx *de = CREATE(dh_encctx); | |
193 | ec_info ei; | |
194 | const char *e; | |
195 | dstr t = DSTR_INIT; | |
196 | ||
197 | key_fulltag(k, &t); | |
198 | if ((e = ec_getinfo(&ei, cstr)) != 0 || | |
199 | (de->g = group_ec(&ei)) == 0) | |
200 | die(EXIT_FAILURE, "bad elliptic curve spec in key `%s': %s", t.buf, e); | |
201 | de->x = MP_NEW; | |
202 | de->y = G_CREATE(de->g); | |
203 | if (G_FROMEC(de->g, de->y, y)) | |
204 | die(EXIT_FAILURE, "bad public curve point `%s'", t.buf); | |
205 | dstr_destroy(&t); | |
206 | return (de); | |
207 | } | |
208 | ||
209 | static kem *dh_encinit(key *k, void *kd) | |
210 | { | |
211 | dh_pub *dp = kd; | |
3688eb75 | 212 | dh_encctx *de = dh_doinit(k, &dp->dp, dp->y, group_prime, "prime"); |
213 | return (&de->k); | |
214 | } | |
215 | ||
216 | static kem *bindh_encinit(key *k, void *kd) | |
217 | { | |
218 | dh_pub *dp = kd; | |
219 | dh_encctx *de = dh_doinit(k, &dp->dp, dp->y, group_binary, "binary"); | |
5c3f75ec | 220 | return (&de->k); |
221 | } | |
222 | ||
223 | static kem *ec_encinit(key *k, void *kd) | |
224 | { | |
225 | ec_pub *ep = kd; | |
226 | dh_encctx *de = ec_doinit(k, ep->cstr, &ep->p); | |
227 | return (&de->k); | |
228 | } | |
229 | ||
230 | static int dh_encdoit(kem *k, dstr *d, ghash *h) | |
231 | { | |
232 | dh_encctx *de = (dh_encctx *)k; | |
233 | mp *r = mprand_range(MP_NEW, de->g->r, &rand_global, 0); | |
234 | ge *x = G_CREATE(de->g); | |
235 | ge *y = G_CREATE(de->g); | |
236 | size_t n = de->g->noctets; | |
237 | buf b; | |
45c0fd36 | 238 | |
5c3f75ec | 239 | G_EXP(de->g, x, de->g->g, r); |
240 | G_EXP(de->g, y, de->y, r); | |
241 | dstr_ensure(d, n); | |
242 | buf_init(&b, d->buf, n); | |
243 | G_TORAW(de->g, &b, y); | |
244 | GH_HASH(h, BBASE(&b), BLEN(&b)); | |
245 | buf_init(&b, d->buf, n); | |
246 | G_TORAW(de->g, &b, x); | |
247 | GH_HASH(h, BBASE(&b), BLEN(&b)); | |
248 | d->len += BLEN(&b); | |
249 | mp_drop(r); | |
250 | G_DESTROY(de->g, x); | |
251 | G_DESTROY(de->g, y); | |
252 | return (0); | |
253 | } | |
254 | ||
255 | static const char *dh_enccheck(kem *k) | |
256 | { | |
257 | dh_encctx *de = (dh_encctx *)k; | |
258 | const char *e; | |
259 | if ((e = G_CHECK(de->g, &rand_global)) != 0) | |
260 | return (0); | |
261 | if (group_check(de->g, de->y)) | |
262 | return ("public key not in subgroup"); | |
263 | return (0); | |
264 | } | |
265 | ||
266 | static void dh_encdestroy(kem *k) | |
267 | { | |
268 | dh_encctx *de = (dh_encctx *)k; | |
269 | G_DESTROY(de->g, de->y); | |
270 | mp_drop(de->x); | |
271 | G_DESTROYGROUP(de->g); | |
6f313264 | 272 | DESTROY(de); |
5c3f75ec | 273 | } |
274 | ||
275 | static const kemops dh_encops = { | |
276 | dh_pubfetch, sizeof(dh_pub), | |
277 | dh_encinit, dh_encdoit, dh_enccheck, dh_encdestroy | |
278 | }; | |
279 | ||
3688eb75 | 280 | static const kemops bindh_encops = { |
281 | dh_pubfetch, sizeof(dh_pub), | |
282 | bindh_encinit, dh_encdoit, dh_enccheck, dh_encdestroy | |
283 | }; | |
284 | ||
5c3f75ec | 285 | static const kemops ec_encops = { |
286 | ec_pubfetch, sizeof(ec_pub), | |
287 | ec_encinit, dh_encdoit, dh_enccheck, dh_encdestroy | |
288 | }; | |
289 | ||
290 | static kem *dh_decinit(key *k, void *kd) | |
291 | { | |
292 | dh_priv *dp = kd; | |
3688eb75 | 293 | dh_encctx *de = dh_doinit(k, &dp->dp, dp->y, group_prime, "prime"); |
294 | de->x = MP_COPY(dp->x); | |
295 | return (&de->k); | |
296 | } | |
297 | ||
298 | static kem *bindh_decinit(key *k, void *kd) | |
299 | { | |
300 | dh_priv *dp = kd; | |
301 | dh_encctx *de = dh_doinit(k, &dp->dp, dp->y, group_binary, "binary"); | |
5c3f75ec | 302 | de->x = MP_COPY(dp->x); |
303 | return (&de->k); | |
304 | } | |
305 | ||
306 | static kem *ec_decinit(key *k, void *kd) | |
307 | { | |
308 | ec_priv *ep = kd; | |
309 | dh_encctx *de = ec_doinit(k, ep->cstr, &ep->p); | |
310 | de->x = MP_COPY(ep->x); | |
311 | return (&de->k); | |
312 | } | |
313 | ||
314 | static int dh_decdoit(kem *k, dstr *d, ghash *h) | |
315 | { | |
316 | dh_encctx *de = (dh_encctx *)k; | |
317 | ge *x = G_CREATE(de->g); | |
318 | size_t n = de->g->noctets; | |
319 | void *p = xmalloc(n); | |
320 | buf b; | |
321 | int rc = -1; | |
322 | ||
323 | buf_init(&b, d->buf, d->len); | |
324 | if (G_FROMRAW(de->g, &b, x) || group_check(de->g, x)) | |
325 | goto done; | |
326 | G_EXP(de->g, x, x, de->x); | |
327 | buf_init(&b, p, n); | |
328 | G_TORAW(de->g, &b, x); | |
329 | GH_HASH(h, BBASE(&b), BLEN(&b)); | |
330 | GH_HASH(h, d->buf, d->len); | |
331 | rc = 0; | |
332 | done: | |
333 | G_DESTROY(de->g, x); | |
334 | xfree(p); | |
335 | return (rc); | |
336 | } | |
337 | ||
338 | static const kemops dh_decops = { | |
339 | dh_privfetch, sizeof(dh_priv), | |
340 | dh_decinit, dh_decdoit, dh_enccheck, dh_encdestroy | |
341 | }; | |
342 | ||
3688eb75 | 343 | static const kemops bindh_decops = { |
344 | dh_privfetch, sizeof(dh_priv), | |
345 | bindh_decinit, dh_decdoit, dh_enccheck, dh_encdestroy | |
346 | }; | |
347 | ||
5c3f75ec | 348 | static const kemops ec_decops = { |
349 | ec_privfetch, sizeof(ec_priv), | |
350 | ec_decinit, dh_decdoit, dh_enccheck, dh_encdestroy | |
351 | }; | |
352 | ||
02dfbd5b MW |
353 | /* --- Symmetric --- */ |
354 | ||
355 | typedef struct symm_ctx { | |
356 | kem k; | |
357 | key_packdef kp; | |
358 | key_bin kb; | |
359 | } symm_ctx; | |
360 | ||
361 | static kem *symm_init(key *k, void *kd) | |
362 | { | |
363 | symm_ctx *s; | |
364 | dstr d = DSTR_INIT; | |
365 | int err; | |
366 | ||
367 | s = CREATE(symm_ctx); | |
368 | ||
369 | key_fulltag(k, &d); | |
370 | s->kp.e = KENC_BINARY; | |
371 | s->kp.p = &s->kb; | |
372 | s->kp.kd = 0; | |
373 | ||
374 | if ((err = key_unpack(&s->kp, kd, &d)) != 0) { | |
375 | die(EXIT_FAILURE, "failed to unpack symmetric key `%s': %s", | |
376 | d.buf, key_strerror(err)); | |
377 | } | |
378 | dstr_destroy(&d); | |
379 | return (&s->k); | |
380 | } | |
381 | ||
382 | static int symm_decdoit(kem *k, dstr *d, ghash *h) | |
383 | { | |
384 | symm_ctx *s = (symm_ctx *)k; | |
385 | ||
386 | GH_HASH(h, s->kb.k, s->kb.sz); | |
387 | GH_HASH(h, d->buf, d->len); | |
388 | return (0); | |
389 | } | |
390 | ||
391 | static int symm_encdoit(kem *k, dstr *d, ghash *h) | |
392 | { | |
393 | dstr_ensure(d, h->ops->c->hashsz); | |
394 | d->len += h->ops->c->hashsz; | |
395 | rand_get(RAND_GLOBAL, d->buf, d->len); | |
396 | return (symm_decdoit(k, d, h)); | |
397 | } | |
398 | ||
399 | static const char *symm_check(kem *k) { return (0); } | |
400 | ||
401 | static void symm_destroy(kem *k) | |
402 | { symm_ctx *s = (symm_ctx *)k; key_unpackdone(&s->kp); } | |
403 | ||
404 | static const kemops symm_encops = { | |
405 | 0, 0, | |
406 | symm_init, symm_encdoit, symm_check, symm_destroy | |
407 | }; | |
408 | ||
409 | static const kemops symm_decops = { | |
410 | 0, 0, | |
411 | symm_init, symm_decdoit, symm_check, symm_destroy | |
412 | }; | |
413 | ||
5c3f75ec | 414 | /* --- The switch table --- */ |
415 | ||
c65df279 | 416 | const struct kemtab kemtab[] = { |
5c3f75ec | 417 | { "rsa", &rsa_encops, &rsa_decops }, |
418 | { "dh", &dh_encops, &dh_decops }, | |
3688eb75 | 419 | { "bindh", &bindh_encops, &bindh_decops }, |
5c3f75ec | 420 | { "ec", &ec_encops, &ec_decops }, |
02dfbd5b | 421 | { "symm", &symm_encops, &symm_decops }, |
5c3f75ec | 422 | { 0, 0, 0 } |
423 | }; | |
424 | ||
425 | /* --- @getkem@ --- * | |
426 | * | |
427 | * Arguments: @key *k@ = the key to load | |
428 | * @const char *app@ = application name | |
429 | * @int wantpriv@ = nonzero if we want to decrypt | |
430 | * | |
431 | * Returns: A key-encapsulating thing. | |
432 | * | |
433 | * Use: Loads a key. | |
434 | */ | |
435 | ||
436 | kem *getkem(key *k, const char *app, int wantpriv) | |
437 | { | |
438 | const char *kalg, *halg = 0, *calg = 0; | |
439 | dstr d = DSTR_INIT; | |
440 | dstr t = DSTR_INIT; | |
441 | size_t n; | |
442 | char *p = 0; | |
443 | const char *q; | |
444 | kem *kk; | |
445 | const struct kemtab *kt; | |
446 | const kemops *ko; | |
447 | void *kd; | |
448 | int e; | |
449 | key_packdef *kp; | |
450 | ||
451 | /* --- Setup stuff --- */ | |
452 | ||
453 | key_fulltag(k, &t); | |
454 | ||
455 | /* --- Get the KEM name --- * | |
456 | * | |
457 | * Take the attribute if it's there; otherwise use the key type. | |
458 | */ | |
459 | ||
460 | n = strlen(app); | |
461 | if ((q = key_getattr(0, k, "kem")) != 0) { | |
462 | dstr_puts(&d, q); | |
463 | p = d.buf; | |
464 | } else if (strncmp(k->type, app, n) == 0 && k->type[n] == '-') { | |
465 | dstr_puts(&d, k->type); | |
466 | p = d.buf + n + 1; | |
467 | } else | |
468 | die(EXIT_FAILURE, "no KEM for key `%s'", t.buf); | |
469 | kalg = p; | |
470 | ||
471 | /* --- Grab the encryption scheme --- * | |
472 | * | |
473 | * Grab it from the KEM if it's there, but override it from the attribute. | |
474 | */ | |
475 | ||
476 | if (p && (p = strchr(p, '/')) != 0) { | |
477 | *p++ = 0; | |
478 | calg = p; | |
479 | } | |
480 | if ((q = key_getattr(0, k, "cipher")) != 0) | |
481 | calg = q; | |
482 | ||
483 | /* --- Grab the hash function --- */ | |
484 | ||
485 | if (p && (p = strchr(p, '/')) != 0) { | |
486 | *p++ = 0; | |
487 | halg = p; | |
488 | } | |
489 | if ((q = key_getattr(0, k, "hash")) != 0) | |
490 | halg = q; | |
491 | ||
492 | /* --- Instantiate the KEM --- */ | |
493 | ||
494 | for (kt = kemtab; kt->name; kt++) { | |
495 | if (strcmp(kt->name, kalg) == 0) | |
496 | goto k_found; | |
497 | } | |
498 | die(EXIT_FAILURE, "key encapsulation mechanism `%s' not found in key `%s'", | |
499 | kalg, t.buf); | |
500 | k_found:; | |
501 | ko = wantpriv ? kt->decops : kt->encops; | |
02dfbd5b MW |
502 | if (!ko->kf) { |
503 | kd = k->k; | |
504 | key_incref(kd); | |
78ec50fa | 505 | kp = 0; |
02dfbd5b MW |
506 | } else { |
507 | kd = xmalloc(ko->kdsz); | |
508 | kp = key_fetchinit(ko->kf, 0, kd); | |
509 | if ((e = key_fetch(kp, k)) != 0) { | |
510 | die(EXIT_FAILURE, "error fetching key `%s': %s", | |
511 | t.buf, key_strerror(e)); | |
512 | } | |
513 | } | |
5c3f75ec | 514 | kk = ko->init(k, kd); |
515 | kk->kp = kp; | |
516 | kk->ops = ko; | |
517 | kk->kd = kd; | |
518 | ||
519 | /* --- Set up the algorithms --- */ | |
520 | ||
521 | if (!halg) | |
522 | kk->h = &rmd160; | |
523 | else if ((kk->h = ghash_byname(halg)) == 0) { | |
524 | die(EXIT_FAILURE, "hash algorithm `%s' not found in key `%s'", | |
525 | halg, t.buf); | |
526 | } | |
527 | ||
528 | if (!calg) | |
529 | kk->c = &blowfish_cbc; | |
530 | else if ((kk->c = gcipher_byname(calg)) == 0) { | |
531 | die(EXIT_FAILURE, "encryption scheme `%s' not found in key `%s'", | |
532 | calg, t.buf); | |
533 | } | |
534 | ||
535 | dstr_reset(&d); | |
536 | if ((q = key_getattr(0, k, "kdf")) == 0) { | |
537 | dstr_putf(&d, "%s-mgf", kk->h->name); | |
538 | q = d.buf; | |
539 | } | |
540 | if ((kk->cx = gcipher_byname(q)) == 0) { | |
541 | die(EXIT_FAILURE, "encryption scheme (KDF) `%s' not found in key `%s'", | |
542 | q, t.buf); | |
543 | } | |
45c0fd36 | 544 | |
5c3f75ec | 545 | dstr_reset(&d); |
546 | if ((q = key_getattr(0, k, "mac")) == 0) { | |
547 | dstr_putf(&d, "%s-hmac", kk->h->name); | |
548 | q = d.buf; | |
549 | } | |
550 | if ((kk->m = gmac_byname(q)) == 0) { | |
551 | die(EXIT_FAILURE, | |
552 | "message authentication code `%s' not found in key `%s'", | |
553 | q, t.buf); | |
554 | } | |
555 | ||
556 | /* --- Tidy up --- */ | |
557 | ||
558 | dstr_destroy(&d); | |
559 | dstr_destroy(&t); | |
560 | return (kk); | |
561 | } | |
562 | ||
563 | /* --- @setupkem@ --- * | |
564 | * | |
565 | * Arguments: @kem *k@ = key-encapsulation thing | |
566 | * @dstr *d@ = key-encapsulation data | |
567 | * @gcipher **cx@ = key-expansion function (for IVs) | |
568 | * @gcipher **c@ = where to put initialized encryption scheme | |
569 | * @gmac **m@ = where to put initialized MAC | |
570 | * | |
571 | * Returns: Zero on success, nonzero on failure. | |
572 | * | |
573 | * Use: Initializes all the various symmetric things from a KEM. | |
574 | */ | |
575 | ||
576 | int setupkem(kem *k, dstr *d, gcipher **cx, gcipher **c, gmac **m) | |
577 | { | |
578 | octet *kd; | |
579 | size_t n, cn, mn; | |
580 | ghash *h; | |
c65df279 | 581 | int rc = -1; |
5c3f75ec | 582 | |
583 | h = GH_INIT(k->h); | |
584 | if (k->ops->doit(k, d, h)) | |
585 | goto done; | |
586 | n = keysz(GH_CLASS(h)->hashsz, k->cx->keysz); | |
587 | if (!n) | |
588 | goto done; | |
589 | kd = GH_DONE(h, 0); | |
590 | *cx = GC_INIT(k->cx, kd, n); | |
591 | ||
592 | cn = keysz(0, k->c->keysz); n = cn; | |
593 | mn = keysz(0, k->m->keysz); if (mn > n) n = mn; | |
594 | kd = xmalloc(n); | |
595 | GC_ENCRYPT(*cx, 0, kd, cn); | |
596 | *c = GC_INIT(k->c, kd, cn); | |
597 | GC_ENCRYPT(*cx, 0, kd, mn); | |
598 | *m = GM_KEY(k->m, kd, mn); | |
599 | xfree(kd); | |
600 | ||
601 | rc = 0; | |
602 | done: | |
603 | GH_DESTROY(h); | |
604 | return (rc); | |
605 | } | |
606 | ||
607 | /* --- @freekem@ --- * | |
608 | * | |
609 | * Arguments: @kem *k@ = key-encapsulation thing | |
610 | * | |
611 | * Returns: --- | |
612 | * | |
613 | * Use: Frees up a key-encapsulation thing. | |
614 | */ | |
615 | ||
616 | void freekem(kem *k) | |
617 | { | |
02dfbd5b MW |
618 | if (!k->ops->kf) |
619 | key_drop(k->kd); | |
620 | else { | |
621 | key_fetchdone(k->kp); | |
622 | xfree(k->kd); | |
623 | } | |
5c3f75ec | 624 | k->ops->destroy(k); |
625 | } | |
626 | ||
627 | /*----- That's all, folks -------------------------------------------------*/ |