chiark / gitweb /
mon/tripemon.in: Add per-peer key selection and mobile options.
[tripe] / server / keymgmt.c
CommitLineData
410c8acf 1/* -*-c-*-
2 *
410c8acf 3 * Key loading and storing
4 *
5 * (c) 2001 Straylight/Edgeware
6 */
7
e04c2d50 8/*----- Licensing notice --------------------------------------------------*
410c8acf 9 *
10 * This file is part of Trivial IP Encryption (TrIPE).
11 *
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
e04c2d50 16 *
410c8acf 17 * TrIPE 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 General Public License for more details.
e04c2d50 21 *
410c8acf 22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
410c8acf 27/*----- Header files ------------------------------------------------------*/
28
29#include "tripe.h"
30
52c03a2a 31/*----- Key groups --------------------------------------------------------*/
32
799e58b9
MW
33/* The key-loading functions here must fill in the kdata slot @g@ and
34 * either @kpriv@ or @kpub@ as appropriate. The caller will take care of
35 * determining @kpub@ given a private key, and of ensuring that @kpriv@ is
36 * null for a public key.
37 */
38
52c03a2a 39typedef struct kgops {
40 const char *ty;
799e58b9
MW
41 int (*loadpriv)(key_data *, kdata *, dstr *, dstr *);
42 int (*loadpub)(key_data *, kdata *, dstr *, dstr *);
52c03a2a 43} kgops;
44
4155aec4
MW
45/* --- @KLOAD@ --- *
46 *
47 * Arguments: @ty@, @TY@ = key type name (lower- and upper-case)
48 * @which@, @WHICH@ = `pub' or `priv' (and upper-case)
49 * @setgroup@ = code to initialize @kd->g@
50 * @setpriv@ = code to initialize @kd->kpriv@
51 * @setpub@ = code to initialize @kd->kpub@
52 *
53 * Use: Generates the body of one of the (rather tedious) key loading
54 * functions. See the description of @KEYTYPES@ below for the
55 * details.
56 */
52c03a2a 57
4155aec4
MW
58#define KLOAD(ty, TY, which, WHICH, setgroup, setpriv, setpub) \
59static int kg##ty##_##which(key_data *d, kdata *kd, dstr *t, dstr *e) \
60{ \
61 key_packstruct kps[TY##_##WHICH##FETCHSZ]; \
62 key_packdef *kp; \
63 ty##_##which p; \
64 int rc; \
65 \
66 /* --- Initialize things we've not set up yet --- */ \
67 \
68 kd->g = 0; kd->kpub = 0; \
69 \
70 /* --- Unpack the key --- */ \
71 \
72 kp = key_fetchinit(ty##_##which##fetch, kps, &p); \
73 if ((rc = key_unpack(kp, d, t)) != 0) { \
74 a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END); \
75 goto fail; \
76 } \
77 \
78 /* --- Extract the pieces of the key --- */ \
79 \
80 setgroup; \
81 setpriv; \
82 kd->kpub = G_CREATE(kd->g); \
83 setpub; \
84 \
85 /* --- We win --- */ \
86 \
87 rc = 0; \
88 goto done; \
89 \
90fail: \
91 if (kd->kpub) G_DESTROY(kd->g, kd->kpub); \
92 if (kd->g) G_DESTROYGROUP(kd->g); \
93 rc = -1; \
94 \
95done: \
96 key_fetchdone(kp); \
97 return (rc); \
52c03a2a 98}
99
4155aec4
MW
100/* --- @KEYTYPES@ --- *
101 *
102 * A list of the various key types, and how to unpack them. Each entry in
103 * the list has the form
104 *
105 * _(ty, TY, setgroup, setpriv, setpub)
106 *
107 * The @ty@ and @TY@ are lower- and upper-case versions of the key type name,
108 * and there should be @key_fetchdef@s called @ty_{priv,pub}fetch@.
109 *
110 * The @setgroup@, @setpriv@ and @setpub@ items are code fragments which are
111 * passed to @KLOAD@ to build appropriate key-loading methods. By the time
112 * these code fragments are run, the key has been unpacked from the incoming
113 * key data using @ty_whichfetch@ into a @ty_which@ structure named @p@.
114 * They can report errors by writing an appropriate token sequence to @e@ and
115 * jumping to @fail@.
116 */
52c03a2a 117
4155aec4
MW
118#define KEYTYPES(_) \
119 \
120 /* --- Diffie-Hellman --- */ \
121 \
122 _(dh, DH, \
123 { kd->g = group_prime(&p.dp); }, \
124 { kd->kpriv = MP_COPY(p.x); }, \
125 { if (G_FROMINT(kd->g, kd->kpub, p.y)) { \
126 a_format(e, "bad-public-vector", A_END); \
127 goto fail; \
128 } \
129 }) \
130 \
131 /* --- Elliptic curves --- */ \
132 \
133 _(ec, EC, \
134 { ec_info ei; const char *err; \
135 if ((err = ec_getinfo(&ei, p.cstr)) != 0) { \
136 a_format(e, "decode-failed", "%s", err, A_END); \
137 goto fail; \
138 } \
139 kd->g = group_ec(&ei); \
140 }, \
141 { kd->kpriv = MP_COPY(p.x); }, \
142 { if (G_FROMEC(kd->g, kd->kpub, &p.p)) { \
143 a_format(e, "bad-public-vector", A_END); \
144 goto fail; \
145 } \
146 })
147
148#define KEYTYPE_DEF(ty, TY, setgroup, setpriv, setpub) \
149 KLOAD(ty, TY, priv, PRIV, setgroup, setpriv, \
150 { G_EXP(kd->g, kd->kpub, kd->g->g, kd->kpriv); }) \
151 KLOAD(ty, TY, pub, PUB, setgroup, { }, setpub) \
152 static const kgops kg##ty##_ops = { #ty, kg##ty##_priv, kg##ty##_pub };
153KEYTYPES(KEYTYPE_DEF)
52c03a2a 154
155/* --- Table of supported key types --- */
156
4155aec4
MW
157static const kgops *kgtab[] = {
158#define KEYTYPE_ENTRY(ty, TY, setgroup, setpriv, setpub) &kg##ty##_ops,
159 KEYTYPES(KEYTYPE_ENTRY)
160#undef KEYTYPE_ENTRY
161 0
162};
52c03a2a 163
b5c45da1 164/*----- Algswitch stuff ---------------------------------------------------*/
165
166/* --- @algs_get@ --- *
167 *
168 * Arguments: @algswitch *a@ = where to put the algorithms
4d36660a
MW
169 * @dstr *e@ = where to write errror tokens
170 * @key_file *kf@ = key file
b5c45da1 171 * @key *k@ = key to inspect
172 *
4d36660a 173 * Returns: Zero if OK; nonzero on error.
b5c45da1 174 *
175 * Use: Extracts an algorithm choice from a key.
176 */
177
4d36660a 178static int algs_get(algswitch *a, dstr *e, key_file *kf, key *k)
b5c45da1 179{
180 const char *p;
a93aacce 181 const bulkcrypto *bulk;
4d36660a 182 char *q, *qq;
b87bffcb 183 dstr d = DSTR_INIT, dd = DSTR_INIT;
4d36660a 184 int rc = -1;
b5c45da1 185
4d36660a
MW
186 /* --- Hash function --- */
187
188 if ((p = key_getattr(kf, k, "hash")) == 0) p = "rmd160";
189 if ((a->h = ghash_byname(p)) == 0) {
190 a_format(e, "unknown-hash", "%s", p, A_END);
191 goto done;
192 }
b5c45da1 193
4d36660a 194 /* --- Symmetric encryption for key derivation --- */
b5c45da1 195
74ee77cb 196 if ((p = key_getattr(kf, k, "mgf")) == 0) {
b5c45da1 197 dstr_reset(&d);
74ee77cb 198 dstr_putf(&d, "%s-mgf", a->h->name);
b5c45da1 199 p = d.buf;
200 }
4d36660a
MW
201 if ((a->mgf = gcipher_byname(p)) == 0) {
202 a_format(e, "unknown-mgf-cipher", "%s", p, A_END);
203 goto done;
204 }
205
a93aacce 206 /* --- Bulk crypto transform --- */
b5c45da1 207
a93aacce
MW
208 if ((p = key_getattr(kf, k, "bulk")) == 0) p = "v0";
209 for (bulk = bulktab; bulk->name && strcmp(p, bulk->name) != 0; bulk++);
210 if (!bulk->name) {
211 a_format(e, "unknown-bulk-transform", "%s", p, A_END);
212 goto done;
213 }
214 a->bulk = bulk;
215
216 /* --- Symmetric encryption for bulk data --- */
217
218 if (!(a->bulk->prim & BCP_CIPHER))
219 a->c = 0;
220 else {
221 if ((p = key_getattr(kf, k, "cipher")) == 0) p = "blowfish-cbc";
222 if ((a->c = gcipher_byname(p)) == 0) {
223 a_format(e, "unknown-cipher", "%s", p, A_END);
4d36660a
MW
224 goto done;
225 }
a93aacce
MW
226 }
227
b87bffcb
MW
228 /* --- Block cipher for miscellaneous use --- */
229
230 if (!(a->bulk->prim & BCP_BLKC))
231 a->b = 0;
232 else {
233 if ((p = key_getattr(kf, k, "blkc")) == 0) {
234 dstr_reset(&dd);
235 dstr_puts(&dd, a->c ? a->c->name : "rijndael-");
236 if ((q = strrchr(dd.buf, '-')) != 0) *q = 0;
237 p = dd.buf;
238 }
239 dstr_reset(&d);
240 dstr_putf(&d, "%s-ecb", p);
241 if ((a->b = gcipher_byname(d.buf)) == 0) {
242 a_format(e, "unknown-blkc", "%s", p, A_END);
243 goto done;
244 }
245 }
246
a93aacce
MW
247 /* --- Message authentication for bulk data --- */
248
249 if (!(a->bulk->prim & BCP_MAC)) {
250 a->m = 0;
251 a->tagsz = 0;
252 } else {
253 if ((p = key_getattr(kf, k, "mac")) != 0) {
254 dstr_reset(&d);
255 dstr_puts(&d, p);
256 if ((q = strchr(d.buf, '/')) != 0)
257 *q++ = 0;
258 if ((a->m = gmac_byname(d.buf)) == 0) {
259 a_format(e, "unknown-mac", "%s", d.buf, A_END);
4d36660a
MW
260 goto done;
261 }
a93aacce
MW
262 if (!q)
263 a->tagsz = a->m->hashsz;
264 else {
265 unsigned long n = strtoul(q, &qq, 0);
266 if (*qq) {
267 a_format(e, "bad-tag-length-string", "%s", q, A_END);
268 goto done;
269 }
270 if (n%8 || n/8 > a->m->hashsz) {
271 a_format(e, "bad-tag-length", "%lu", n, A_END);
272 goto done;
273 }
274 a->tagsz = n/8;
275 }
276 } else {
277 dstr_reset(&d);
278 dstr_putf(&d, "%s-hmac", a->h->name);
279 if ((a->m = gmac_byname(d.buf)) == 0) {
280 a_format(e, "no-hmac-for-hash", "%s", a->h->name, A_END);
4d36660a
MW
281 goto done;
282 }
a93aacce 283 a->tagsz = a->h->hashsz/2;
4d36660a 284 }
b5c45da1 285 }
286
a93aacce
MW
287 /* --- All done --- */
288
4d36660a 289 rc = 0;
b5c45da1 290done:
291 dstr_destroy(&d);
b87bffcb 292 dstr_destroy(&dd);
4d36660a 293 return (rc);
b5c45da1 294}
295
296/* --- @algs_check@ --- *
297 *
298 * Arguments: @algswitch *a@ = a choice of algorithms
4d36660a 299 * @dstr *e@ = where to write error tokens
b5c45da1 300 * @const group *g@ = the group we're working in
301 *
4d36660a 302 * Returns: Zero if OK; nonzero on error.
b5c45da1 303 *
304 * Use: Checks an algorithm choice for sensibleness. This also
305 * derives some useful information from the choices, and you
306 * must call this before committing the algorithm selection
307 * for use by @keyset@ functions.
308 */
309
4d36660a 310static int algs_check(algswitch *a, dstr *e, const group *g)
b5c45da1 311{
a93aacce
MW
312 /* --- Check the bulk crypto transform --- */
313
314 if (a->bulk->check(a, e)) return (-1);
315
b5c45da1 316 /* --- Derive the key sizes --- *
317 *
318 * Must ensure that we have non-empty keys. This isn't ideal, but it
383a9d71
MW
319 * provides a handy sanity check. Also must be based on a 64- or 128-bit
320 * block cipher or we can't do the data expiry properly.
b5c45da1 321 */
322
323 a->hashsz = a->h->hashsz;
a93aacce 324 if (a->c && (a->cksz = keysz(a->hashsz, a->c->keysz)) == 0) {
4d36660a
MW
325 a_format(e, "cipher", "%s", a->c->name,
326 "no-key-size", "%lu", (unsigned long)a->hashsz,
327 A_END);
328 return (-1);
329 }
a93aacce 330 if (a->m && (a->mksz = keysz(a->hashsz, a->m->keysz)) == 0) {
4d36660a
MW
331 a_format(e, "mac", "%s", a->m->name,
332 "no-key-size", "%lu", (unsigned long)a->hashsz,
333 A_END);
334 return (-1);
335 }
b87bffcb
MW
336 if (a->b && (a->bksz = keysz(a->hashsz, a->b->keysz)) == 0) {
337 a_format(e, "blkc", "%.*s", strlen(a->b->name) - 4, a->b->name,
338 "no-key-size", "%lu", (unsigned long)a->hashsz,
339 A_END);
340 return (-1);
341 }
b5c45da1 342
383a9d71
MW
343 /* --- Derive the data limit --- */
344
a93aacce 345 if (a->c && a->c->blksz < 16) a->expsz = MEG(64);
383a9d71
MW
346 else a->expsz = MEG(2048);
347
b5c45da1 348 /* --- Ensure the MGF accepts hashes as keys --- */
349
4d36660a
MW
350 if (keysz(a->hashsz, a->mgf->keysz) != a->hashsz) {
351 a_format(e, "mgf", "%s", a->mgf->name,
352 "restrictive-key-schedule",
353 A_END);
354 return (-1);
355 }
b5c45da1 356
357 /* --- All ship-shape and Bristol-fashion --- */
358
359 return (0);
360}
361
799e58b9 362/* --- @km_samealgsp@ --- *
b5c45da1 363 *
799e58b9 364 * Arguments: @const kdata *kdx, *kdy@ = two key data objects
b5c45da1 365 *
799e58b9 366 * Returns: Nonzero if their two algorithm selections are the same.
b5c45da1 367 *
368 * Use: Checks sameness of algorithm selections: used to ensure that
369 * peers are using sensible algorithms.
370 */
371
799e58b9 372int km_samealgsp(const kdata *kdx, const kdata *kdy)
b5c45da1 373{
799e58b9
MW
374 const algswitch *a = &kdx->algs, *aa = &kdy->algs;
375
b87bffcb
MW
376 return (group_samep(kdx->g, kdy->g) &&
377 a->c == aa->c && a->b == aa->b &&
799e58b9 378 a->mgf == aa->mgf && a->h == aa->h &&
b5c45da1 379 a->m == aa->m && a->tagsz == aa->tagsz);
380}
381
799e58b9
MW
382/*----- Key data and key nodes --------------------------------------------*/
383
384typedef struct keyhalf {
385 const char *kind;
386 int (*load)(const kgops *, key_data *, kdata *, dstr *, dstr *);
387 const char *kr;
388 key_file *kf;
389 fwatch w;
390 sym_table tab;
391} keyhalf;
392
393/* --- @kh_loadpub@, @kh_loadpriv@ --- *
394 *
395 * Arguments: @const kgops *ko@ = key-group operations for key type
396 * @key_data *d@ = key data object as stored in keyring
397 * @kdata *kd@ = our key-data object to fill in
398 * @dstr *t@ = the key tag name
399 * @dstr *e@ = a string to write error tokens to
400 *
401 * Returns: Zero on success, @-1@ on error.
402 *
403 * Use: These functions handle the main difference between public and
404 * private key halves. They are responsible for setting @g@,
405 * @kpriv@ and @kpub@ appropriately in all keys, handling the
406 * mismatch between the largely half-indifferent calling code
407 * and the group-specific loading functions.
408 *
409 * The function @kh_loadpriv@ is also responsible for checking
410 * the group for goodness. We don't bother checking public
411 * keys, because each public key we actually end up using must
412 * share a group with a private key which we'll already have
413 * checked.
414 */
415
416static int kh_loadpub(const kgops *ko, key_data *d, kdata *kd,
417 dstr *t, dstr *e)
418{
419 int rc;
420
421 if ((rc = ko->loadpub(d, kd, t, e)) != 0)
422 goto fail_0;
423 if (group_check(kd->g, kd->kpub)) {
73174919 424 a_format(e, "bad-public-group-element", A_END);
799e58b9
MW
425 goto fail_1;
426 }
427 kd->kpriv = 0;
428 return (0);
429
430fail_1:
431 G_DESTROY(kd->g, kd->kpub);
432 G_DESTROYGROUP(kd->g);
433fail_0:
434 return (-1);
435}
436
437static int kh_loadpriv(const kgops *ko, key_data *d, kdata *kd,
438 dstr *t, dstr *e)
439{
440 int rc;
441 const char *err;
442
443 if ((rc = ko->loadpriv(d, kd, t, e)) != 0)
444 goto fail_0;
445 if ((err = G_CHECK(kd->g, &rand_global)) != 0) {
446 a_format(e, "bad-group", "%s", err, A_END);
447 goto fail_1;
448 }
799e58b9
MW
449 return (0);
450
451fail_1:
452 mp_drop(kd->kpriv);
4155aec4 453 G_DESTROY(kd->g, kd->kpub);
799e58b9
MW
454 G_DESTROYGROUP(kd->g);
455fail_0:
456 return (-1);
457}
458
459static struct keyhalf
460 priv = { "private", kh_loadpriv },
461 pub = { "public", kh_loadpub };
410c8acf 462
463/* --- @keymoan@ --- *
464 *
56814747 465 * Arguments: @const char *file@ = name of the file
e04c2d50
MW
466 * @int line@ = line number in file
467 * @const char *msg@ = error message
4d36660a 468 * @void *p@ = argument pointer (indicates which keyring)
410c8acf 469 *
e04c2d50 470 * Returns: ---
410c8acf 471 *
e04c2d50 472 * Use: Reports an error message about loading a key file.
410c8acf 473 */
474
475static void keymoan(const char *file, int line, const char *msg, void *p)
f43df819 476{
799e58b9 477 keyhalf *kh = p;
4d36660a
MW
478
479 if (!line) {
799e58b9 480 a_warn("KEYMGMT", "%s-keyring", kh->kind, "%s", file,
4d36660a
MW
481 "io-error", "?ERRNO", A_END);
482 } else {
799e58b9 483 a_warn("KEYMGMT", "%s-keyring", kh->kind, "%s", file, "line", "%d", line,
4d36660a
MW
484 "%s", msg, A_END);
485 }
f43df819 486}
410c8acf 487
799e58b9 488/* --- @kh_reopen@ --- *
fc5f4823 489 *
799e58b9 490 * Arguments: @keyhalf *kh@ = pointer to keyhalf structure
fc5f4823 491 *
799e58b9 492 * Returns: Zero on success, @-1@ on error.
fc5f4823 493 *
799e58b9
MW
494 * Use: Reopens the key file for the appropriate key half. If this
495 * fails, everything is left as it was; if it succeeds, then the
496 * old file is closed (if it was non-null) and the new one put
497 * in its place.
fc5f4823
MW
498 */
499
799e58b9 500static int kh_reopen(keyhalf *kh)
fc5f4823 501{
799e58b9 502 key_file *kf = CREATE(key_file);
fc5f4823 503
799e58b9
MW
504 if (key_open(kf, kh->kr, KOPEN_READ, keymoan, kh)) {
505 a_warn("KEYMGMT", "%s-keyring", kh->kind, "%s", kh->kr,
7f81b1b4 506 "io-error", "?ERRNO", A_END);
799e58b9
MW
507 DESTROY(kf);
508 return (-1);
509 } else {
510 if (kh->kf) {
511 key_close(kh->kf);
512 DESTROY(kh->kf);
513 }
514 kh->kf = kf;
515 return (0);
516 }
517}
fc5f4823 518
799e58b9
MW
519/* --- @kh_init@ --- *
520 *
521 * Arguments: @keyhalf *kh@ = pointer to keyhalf structure to set up
522 * @const char *kr@ = name of the keyring file
523 *
524 * Returns: ---
525 *
526 * Use: Initialize a keyhalf structure, maintaining the private or
527 * public keys. Intended to be called during initialization:
528 * exits if there's some kind of problem.
529 */
fc5f4823 530
799e58b9
MW
531static void kh_init(keyhalf *kh, const char *kr)
532{
533 kh->kr = kr;
534 fwatch_init(&kh->w, kr);
535 sym_create(&kh->tab);
536 kh->kf = 0;
537
538 if (kh_reopen(kh))
539 die(EXIT_FAILURE, "failed to load %s keyring `%s'", kh->kind, kr);
fc5f4823
MW
540}
541
799e58b9 542/* --- @kh_load@ --- *
410c8acf 543 *
799e58b9
MW
544 * Arguments: @keyhalf *kh@ = pointer to keyhalf
545 * @const char *tag@ = key tag to be loaded
546 * @int complainp@ = whether to complain about missing keys
410c8acf 547 *
799e58b9
MW
548 * Returns: Pointer to a @kdata@ structure if successful, or null on
549 * failure.
410c8acf 550 *
799e58b9
MW
551 * Use: Attempts to load a key from the current key file. This
552 * function always reads data from the file: it's used when
553 * there's a cache miss from @kh_find@, and when refreshing the
554 * known keys in @kh_refresh@. The returned kdata has a
555 * reference count of exactly 1, and has no home knode.
410c8acf 556 */
557
799e58b9 558static kdata *kh_load(keyhalf *kh, const char *tag, int complainp)
410c8acf 559{
52c03a2a 560 dstr t = DSTR_INIT;
4d36660a 561 dstr e = DSTR_INIT;
799e58b9
MW
562 key *k;
563 key_data **d;
564 kdata *kd;
565 const char *ty;
566 const kgops **ko;
52c03a2a 567
799e58b9 568 /* --- Find the key and grab its tag --- */
52c03a2a 569
799e58b9
MW
570 if (key_qtag(kh->kf, tag, &t, &k, &d)) {
571 if (complainp) {
572 a_warn("KEYMGMT", "%s-keyring", kh->kind, "%s", kh->kr,
573 "key-not-found", "%s", tag, A_END);
574 }
575 goto fail_0;
52c03a2a 576 }
577
799e58b9
MW
578 /* --- Find the key's group type and the appropriate operations --- *
579 *
580 * There are several places to look for the key type. The most obvious is
581 * the `kx-group' key attribute. But there's also the key type itself, for
582 * compatibility reasons.
583 */
52c03a2a 584
799e58b9
MW
585 ty = key_getattr(kh->kf, k, "kx-group");
586 if (!ty && strncmp(k->type, "tripe-", 6) == 0) ty = k->type + 6;
587 if (!ty) ty = "dh";
52c03a2a 588
799e58b9
MW
589 for (ko = kgtab; *ko; ko++)
590 if (strcmp((*ko)->ty, ty) == 0) goto foundko;
591 a_warn("KEYMGMT", "%s-keyring", kh->kind,
592 "%s", kh->kr, "key", "%s", t.buf,
593 "unknown-group-type", "%s", ty, A_END);
594 goto fail_0;
595
596foundko:
597 kd = CREATE(kdata);
598 if (kh->load(*ko, *d, kd, &t, &e)) {
599 a_warn("KEYMGMT", "%s-keyring", kh->kind,
600 "%s", kh->kr, "key" "%s", t.buf,
4d36660a 601 "*%s", e.buf, A_END);
799e58b9 602 goto fail_1;
52c03a2a 603 }
604
799e58b9
MW
605 if (algs_get(&kd->algs, &e, kh->kf, k) ||
606 (kd->kpriv && algs_check(&kd->algs, &e, kd->g))) {
607 a_warn("KEYMGMT", "%s-keyring", kh->kind,
608 "%s", kh->kr, "key", "%s", t.buf,
4d36660a 609 "*%s", e.buf, A_END);
799e58b9 610 goto fail_2;
410c8acf 611 }
52c03a2a 612
799e58b9
MW
613 kd->tag = xstrdup(t.buf);
614 kd->indexsz = mp_octets(kd->g->r);
615 kd->ref = 1;
616 kd->kn = 0;
617 kd->t_exp = k->exp;
52c03a2a 618
619 IF_TRACING(T_KEYMGMT, {
799e58b9 620 trace(T_KEYMGMT, "keymgmt: loaded %s key `%s'", kh->kind, t.buf);
52c03a2a 621 IF_TRACING(T_CRYPTO, {
799e58b9
MW
622 trace(T_CRYPTO, "crypto: r = %s", mpstr(kd->g->r));
623 trace(T_CRYPTO, "crypto: h = %s", mpstr(kd->g->h));
624 if (kd->kpriv)
625 trace(T_CRYPTO, "crypto: x = %s", mpstr(kd->kpriv));
626 trace(T_CRYPTO, "crypto: cipher = %s", kd->algs.c->name);
627 trace(T_CRYPTO, "crypto: mgf = %s", kd->algs.mgf->name);
628 trace(T_CRYPTO, "crypto: hash = %s", kd->algs.h->name);
b5c45da1 629 trace(T_CRYPTO, "crypto: mac = %s/%lu",
799e58b9 630 kd->algs.m->name, (unsigned long)kd->algs.tagsz * 8);
52c03a2a 631 })
632 })
633
799e58b9 634 goto done;
52c03a2a 635
799e58b9
MW
636fail_2:
637 if (kd->kpriv) mp_drop(kd->kpriv);
638 G_DESTROY(kd->g, kd->kpub);
639 G_DESTROYGROUP(kd->g);
640fail_1:
641 DESTROY(kd);
642fail_0:
643 kd = 0;
644done:
52c03a2a 645 dstr_destroy(&t);
4d36660a 646 dstr_destroy(&e);
799e58b9 647 return (kd);
410c8acf 648}
649
799e58b9 650/* --- @kh_find@ --- *
410c8acf 651 *
799e58b9
MW
652 * Arguments: @keyhalf *kh@ = pointer to the keyhalf
653 * @const char *tag@ = key to be obtained
654 * @int complainp@ = whether to complain about missing keys
410c8acf 655 *
799e58b9 656 * Returns: A pointer to the kdata, or null on error.
410c8acf 657 *
799e58b9
MW
658 * Use: Obtains kdata, maybe from the cache. This won't update a
659 * stale cache entry, though @kh_refresh@ ought to have done
660 * that already. The returned kdata object may be shared with
661 * other users. (One of this function's responsibilities, over
662 * @kh_load@, is to set the home knode of a freshly loaded
663 * kdata.)
410c8acf 664 */
665
799e58b9 666static kdata *kh_find(keyhalf *kh, const char *tag, int complainp)
410c8acf 667{
799e58b9
MW
668 knode *kn;
669 kdata *kd;
670 unsigned f;
410c8acf 671
799e58b9
MW
672 kn = sym_find(&kh->tab, tag, -1, sizeof(knode), &f);
673
674 if (f) {
675 if (kn->f & KNF_BROKEN) {
676 T( if (complainp)
677 trace(T_KEYMGMT, "keymgmt: key `%s' marked as broken", tag); )
678 return (0);
679 }
680
681 kd = kn->kd;
682 if (kd) kd->ref++;
683 T( trace(T_KEYMGMT, "keymgmt: %scache hit for key `%s'",
684 kd ? "" : "negative ", tag); )
685 return (kd);
686 } else {
687 kd = kh_load(kh, tag, complainp);
688 kn->kd = kd;
689 kn->kh = kh;
690 kn->f = 0;
691 if (!kd)
692 kn->f |= KNF_BROKEN;
693 else {
694 kd->kn = kn;
695 kd->ref++;
696 }
697 return (kd);
410c8acf 698 }
410c8acf 699}
700
799e58b9 701/* --- @kh_refresh@ --- *
410c8acf 702 *
799e58b9 703 * Arguments: @keyhalf *kh@ = pointer to the keyhalf
410c8acf 704 *
799e58b9
MW
705 * Returns: Zero if nothing needs to be done; nonzero if peers should
706 * refresh their keys.
410c8acf 707 *
799e58b9
MW
708 * Use: Refreshes cached keys from files.
709 *
710 * Each active knode is examined to see if a new key is
711 * available: the return value is nonzero if any new keys are.
712 * A key is considered new if its algorithms, public key, or
713 * expiry time are/is different.
714 *
715 * Stub knodes (with no kdata attached) are removed, so that a
716 * later retry can succeed if the file has been fixed. (This
717 * doesn't count as a change, since no peers should be relying
718 * on a nonexistent key.)
410c8acf 719 */
720
799e58b9 721static int kh_refresh(keyhalf *kh)
410c8acf 722{
799e58b9
MW
723 knode *kn;
724 kdata *kd;
725 sym_iter i;
726 int changep = 0;
727
728 if (!fwatch_update(&kh->w, kh->kr) || kh_reopen(kh))
729 return (0);
730
731 T( trace(T_KEYMGMT, "keymgmt: rescan %s keyring `%s'", kh->kind, kh->kr); )
732 for (sym_mkiter(&i, &kh->tab); (kn = sym_next(&i)) != 0; ) {
733 if (!kn->kd) {
734 T( trace(T_KEYMGMT, "keymgmt: discard stub entry for key `%s'",
735 SYM_NAME(kn)); )
736 sym_remove(&kh->tab, kn);
737 continue;
738 }
739 if ((kd = kh_load(kh, SYM_NAME(kn), 1)) == 0) {
740 if (!(kn->f & KNF_BROKEN)) {
741 T( trace(T_KEYMGMT, "keymgmt: failed to load new key `%s': "
742 "marking it as broken",
743 SYM_NAME(kn)); )
744 kn->f |= KNF_BROKEN;
745 }
746 continue;
747 }
748 kn->f &= ~KNF_BROKEN;
749 if (kd->t_exp == kn->kd->t_exp &&
750 km_samealgsp(kd, kn->kd) &&
751 G_EQ(kd->g, kd->kpub, kn->kd->kpub)) {
752 T( trace(T_KEYMGMT, "keymgmt: key `%s' unchanged", SYM_NAME(kn)); )
753 continue;
754 }
755 T( trace(T_KEYMGMT, "keymgmt: loaded new version of key `%s'",
756 SYM_NAME(kn)); )
757 km_unref(kn->kd);
758 kd->kn = kn;
759 kn->kd = kd;
760 changep = 1;
761 }
410c8acf 762
799e58b9
MW
763 return (changep);
764}
410c8acf 765
799e58b9 766/*----- Main code ---------------------------------------------------------*/
410c8acf 767
799e58b9
MW
768const char *tag_priv;
769kdata *master;
410c8acf 770
410c8acf 771/* --- @km_init@ --- *
772 *
799e58b9
MW
773 * Arguments: @const char *privkr@ = private keyring file
774 * @const char *pubkr@ = public keyring file
775 * @const char *ptag@ = default private-key tag
410c8acf 776 *
777 * Returns: ---
778 *
799e58b9
MW
779 * Use: Initializes the key-management machinery, loading the
780 * keyrings and so on.
410c8acf 781 */
782
799e58b9 783void km_init(const char *privkr, const char *pubkr, const char *ptag)
410c8acf 784{
b5c45da1 785 const gchash *const *hh;
410c8acf 786
b5c45da1 787 for (hh = ghashtab; *hh; hh++) {
788 if ((*hh)->hashsz > MAXHASHSZ) {
789 die(EXIT_FAILURE, "INTERNAL ERROR: %s hash length %lu > MAXHASHSZ %d",
790 (*hh)->name, (unsigned long)(*hh)->hashsz, MAXHASHSZ);
791 }
792 }
793
799e58b9
MW
794 kh_init(&priv, privkr);
795 kh_init(&pub, pubkr);
796
797 tag_priv = ptag;
798 if ((master = km_findpriv(ptag)) == 0) exit(EXIT_FAILURE);
410c8acf 799}
800
799e58b9 801/* --- @km_reload@ --- *
410c8acf 802 *
799e58b9 803 * Arguments: ---
410c8acf 804 *
799e58b9 805 * Returns: Zero if OK, nonzero to force reloading of keys.
410c8acf 806 *
799e58b9 807 * Use: Checks the keyrings to see if they need reloading.
410c8acf 808 */
809
799e58b9 810int km_reload(void)
410c8acf 811{
799e58b9
MW
812 int changep = 0;
813 kdata *kd;
814
815 if (kh_refresh(&priv)) {
816 changep = 1;
817 kd = master->kn->kd;
35c8b547 818 if (kd != master) {
799e58b9
MW
819 km_unref(master);
820 km_ref(kd);
821 master = kd;
822 }
823 }
824 if (kh_refresh(&pub))
825 changep = 1;
826 return (changep);
827}
52c03a2a 828
799e58b9
MW
829/* --- @km_findpub@, @km_findpriv@ --- *
830 *
831 * Arguments: @const char *tag@ = key tag to load
832 *
833 * Returns: Pointer to the kdata object if successful, or null on error.
834 *
835 * Use: Fetches a public or private key from the keyring.
836 */
52c03a2a 837
799e58b9 838kdata *km_findpub(const char *tag) { return (kh_find(&pub, tag, 1)); }
410c8acf 839
799e58b9
MW
840kdata *km_findpriv(const char *tag)
841{
842 kdata *kd;
52c03a2a 843
799e58b9
MW
844 /* Unpleasantness for the sake of compatibility. */
845 if (!tag && (kd = kh_find(&priv, "tripe", 0)) != 0) return (kd);
846 else return (kh_find(&priv, tag ? tag : "tripe-dh", 1));
847}
52c03a2a 848
799e58b9
MW
849/* --- @km_tag@ --- *
850 *
851 * Arguments: @kdata *kd@ - pointer to the kdata object
852 *
853 * Returns: A pointer to the short tag by which the kdata was loaded.
854 */
52c03a2a 855
799e58b9 856const char *km_tag(kdata *kd) { return (SYM_NAME(kd->kn)); }
52c03a2a 857
799e58b9
MW
858/* --- @km_ref@ --- *
859 *
860 * Arguments: @kdata *kd@ = pointer to the kdata object
861 *
862 * Returns: ---
863 *
864 * Use: Claim a new reference to a kdata object.
865 */
52c03a2a 866
799e58b9 867void km_ref(kdata *kd) { kd->ref++; }
52c03a2a 868
799e58b9
MW
869/* --- @km_unref@ --- *
870 *
871 * Arguments: @kdata *kd@ = pointer to the kdata object
872 *
873 * Returns: ---
874 *
875 * Use: Releases a reference to a kdata object.
876 */
52c03a2a 877
799e58b9
MW
878void km_unref(kdata *kd)
879{
880 if (--kd->ref) return;
881 if (kd->kpriv) mp_drop(kd->kpriv);
882 G_DESTROY(kd->g, kd->kpub);
883 xfree(kd->tag);
884 G_DESTROYGROUP(kd->g);
885}
886
410c8acf 887/*----- That's all, folks -------------------------------------------------*/