410c8acf |
1 | /* -*-c-*- |
2 | * |
b4e56668 |
3 | * $Id: keymgmt.c,v 1.5 2004/04/08 01:36:17 mdw Exp $ |
410c8acf |
4 | * |
5 | * Key loading and storing |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Trivial IP Encryption (TrIPE). |
13 | * |
14 | * TrIPE is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * TrIPE is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with TrIPE; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
410c8acf |
29 | /*----- Header files ------------------------------------------------------*/ |
30 | |
31 | #include "tripe.h" |
32 | |
33 | /*----- Global variables --------------------------------------------------*/ |
34 | |
52c03a2a |
35 | group *gg; |
36 | mp *kpriv; |
410c8acf |
37 | |
38 | /*----- Static variables --------------------------------------------------*/ |
39 | |
40 | static key_file *kf_pub; |
41 | static const char *kr_priv, *kr_pub, *tag_priv; |
42 | static fwatch w_priv, w_pub; |
43 | |
52c03a2a |
44 | /*----- Key groups --------------------------------------------------------*/ |
45 | |
46 | typedef struct kgops { |
47 | const char *ty; |
48 | const char *(*loadpriv)(key_data *, group **, mp **, dstr *); |
49 | const char *(*loadpub)(key_data *, group **, ge **, dstr *); |
50 | } kgops; |
51 | |
52 | /* --- Diffie-Hellman --- */ |
53 | |
54 | static const char *kgdh_priv(key_data *kd, group **g, mp **x, dstr *t) |
55 | { |
56 | key_packstruct kps[DH_PRIVFETCHSZ]; |
57 | key_packdef *kp; |
58 | dh_priv dp; |
59 | const char *e; |
60 | int rc; |
61 | |
62 | kp = key_fetchinit(dh_privfetch, kps, &dp); |
63 | if ((rc = key_unpack(kp, kd, t)) != 0) { |
64 | e = key_strerror(rc); |
65 | goto done; |
66 | } |
67 | *g = group_prime(&dp.dp); |
68 | *x = MP_COPY(dp.x); |
69 | e = 0; |
70 | done: |
71 | key_fetchdone(kp); |
72 | return (e); |
73 | } |
74 | |
75 | static const char *kgdh_pub(key_data *kd, group **g, ge **p, dstr *t) |
76 | { |
77 | key_packstruct kps[DH_PUBFETCHSZ]; |
78 | key_packdef *kp; |
79 | dh_pub dp; |
80 | const char *e; |
81 | int rc; |
82 | |
83 | kp = key_fetchinit(dh_pubfetch, kps, &dp); |
84 | if ((rc = key_unpack(kp, kd, t)) != 0) { |
85 | e = key_strerror(rc); |
86 | goto done; |
87 | } |
88 | *g = group_prime(&dp.dp); |
89 | *p = G_CREATE(*g); |
90 | if (G_FROMINT(*g, *p, dp.y)) { |
91 | e = "bad public value"; |
92 | goto done; |
93 | } |
94 | e = 0; |
95 | done: |
96 | key_fetchdone(kp); |
97 | return (e); |
98 | } |
99 | |
100 | static const kgops kgdh_ops = { "tripe-dh", kgdh_priv, kgdh_pub }; |
101 | |
102 | /* --- Elliptic curve --- */ |
103 | |
104 | static const char *kgec_priv(key_data *kd, group **g, mp **x, dstr *t) |
105 | { |
106 | key_packstruct kps[EC_PRIVFETCHSZ]; |
107 | key_packdef *kp; |
108 | ec_priv ep; |
109 | ec_info ei; |
110 | const char *e; |
111 | int rc; |
112 | |
113 | kp = key_fetchinit(ec_privfetch, kps, &ep); |
114 | if ((rc = key_unpack(kp, kd, t)) != 0) { |
115 | e = key_strerror(rc); |
116 | goto done; |
117 | } |
118 | if ((e = ec_getinfo(&ei, ep.cstr)) != 0) |
119 | goto done; |
120 | *g = group_ec(&ei); |
121 | *x = MP_COPY(ep.x); |
122 | e = 0; |
123 | done: |
124 | key_fetchdone(kp); |
125 | return (e); |
126 | } |
127 | |
128 | static const char *kgec_pub(key_data *kd, group **g, ge **p, dstr *t) |
129 | { |
130 | key_packstruct kps[EC_PUBFETCHSZ]; |
131 | key_packdef *kp; |
132 | ec_pub ep; |
133 | ec_info ei; |
134 | const char *e; |
135 | int rc; |
136 | |
137 | kp = key_fetchinit(ec_pubfetch, kps, &ep); |
138 | if ((rc = key_unpack(kp, kd, t)) != 0) { |
139 | e = key_strerror(rc); |
140 | goto done; |
141 | } |
142 | if ((e = ec_getinfo(&ei, ep.cstr)) != 0) |
143 | goto done; |
144 | *g = group_ec(&ei); |
145 | *p = G_CREATE(*g); |
146 | if (G_FROMEC(*g, *p, &ep.p)) { |
147 | e = "bad public point"; |
148 | goto done; |
149 | } |
150 | e = 0; |
151 | done: |
152 | key_fetchdone(kp); |
153 | return (e); |
154 | } |
155 | |
156 | static const kgops kgec_ops = { "tripe-ec", kgec_priv, kgec_pub }; |
157 | |
158 | /* --- Table of supported key types --- */ |
159 | |
160 | static const kgops *kgtab[] = { &kgdh_ops, &kgec_ops, 0 }; |
161 | |
410c8acf |
162 | /*----- Main code ---------------------------------------------------------*/ |
163 | |
164 | /* --- @keymoan@ --- * |
165 | * |
56814747 |
166 | * Arguments: @const char *file@ = name of the file |
410c8acf |
167 | * @int line@ = line number in file |
168 | * @const char *msg@ = error message |
169 | * @void *p@ = argument pointer |
170 | * |
171 | * Returns: --- |
172 | * |
173 | * Use: Reports an error message about loading a key file. |
174 | */ |
175 | |
176 | static void keymoan(const char *file, int line, const char *msg, void *p) |
52c03a2a |
177 | { a_warn("%s:%i: error: %s", file, line, msg); } |
410c8acf |
178 | |
179 | /* --- @loadpriv@ --- * |
180 | * |
181 | * Arguments: @dstr *d@ = string to write errors in |
410c8acf |
182 | * |
183 | * Returns: Zero if OK, nonzero on error. |
184 | * |
185 | * Use: Loads the private key from its keyfile. |
186 | */ |
187 | |
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188 | static int loadpriv(dstr *d) |
410c8acf |
189 | { |
190 | key_file kf; |
52c03a2a |
191 | key *k; |
192 | key_data *kd; |
193 | dstr t = DSTR_INIT; |
194 | group *g = 0; |
195 | mp *x = 0; |
196 | int rc = -1; |
197 | const kgops **ko; |
198 | const char *e; |
199 | |
200 | /* --- Open the private key file --- */ |
410c8acf |
201 | |
202 | if (key_open(&kf, kr_priv, KOPEN_READ, keymoan, 0)) { |
203 | dstr_putf(d, "error reading private keyring `%s': %s", |
204 | kr_priv, strerror(errno)); |
52c03a2a |
205 | goto done_0; |
206 | } |
207 | |
208 | /* --- Find the private key --- */ |
209 | |
210 | if (key_qtag(&kf, tag_priv, &t, &k, &kd)) { |
211 | dstr_putf(d, "private key `%s' not found in keyring `%s'", |
212 | tag_priv, kr_priv); |
213 | goto done_1; |
214 | } |
215 | |
216 | /* --- Look up the key type in the table --- */ |
217 | |
218 | for (ko = kgtab; *ko; ko++) { |
219 | if (strcmp((*ko)->ty, k->type) == 0) |
220 | goto tymatch; |
221 | } |
222 | dstr_putf(d, "private key `%s' has unknown type `%s'", t.buf, k->type); |
223 | goto done_1; |
224 | tymatch:; |
225 | |
226 | /* --- Load the key --- */ |
227 | |
228 | if ((e = (*ko)->loadpriv(kd, &g, &x, &t)) != 0) { |
229 | dstr_putf(d, "error reading private key `%s': %s", t.buf, e); |
230 | goto done_1; |
231 | } |
232 | |
233 | /* --- Check that the key is sensible --- */ |
234 | |
235 | if ((e = G_CHECK(g, &rand_global)) != 0) { |
236 | dstr_putf(d, "bad group in private key `%s': %s", t.buf, e); |
237 | goto done_1; |
238 | } |
239 | |
240 | /* --- Good, we're happy --- * |
241 | * |
242 | * Dodginess! We change the group over here, but don't free any old group |
243 | * elements. This assumes that the new group is basically the same as the |
244 | * old one, and will happily adopt the existing elements. If it isn't, |
245 | * then we lose badly. Check this, then. |
246 | */ |
247 | |
248 | if (gg) { |
249 | if (!group_samep(g, gg)) { |
250 | dstr_putf(d, "private key `%s' has different group", t.buf); |
251 | goto done_1; |
410c8acf |
252 | } |
52c03a2a |
253 | G_DESTROYGROUP(gg); |
410c8acf |
254 | } |
52c03a2a |
255 | if (kpriv) |
256 | mp_drop(kpriv); |
257 | |
258 | /* --- Dump out the group --- */ |
259 | |
260 | IF_TRACING(T_KEYMGMT, { |
261 | trace(T_KEYMGMT, "keymgmt: extracted private key `%s'", t.buf); |
262 | IF_TRACING(T_CRYPTO, { |
263 | trace(T_CRYPTO, "crypto: r = %s", mpstr(g->r)); |
264 | trace(T_CRYPTO, "crypto: h = %s", mpstr(g->h)); |
265 | trace(T_CRYPTO, "crypto: x = %s", mpstr(x)); |
266 | }) |
267 | }) |
268 | |
269 | /* --- Success! --- */ |
270 | |
271 | gg = g; g = 0; |
272 | kpriv = x; x = 0; |
273 | rc = 0; |
274 | |
275 | /* --- Tidy up --- */ |
276 | |
277 | done_1: |
278 | key_close(&kf); |
279 | done_0: |
280 | dstr_destroy(&t); |
281 | if (x) mp_drop(x); |
282 | if (g) G_DESTROYGROUP(g); |
410c8acf |
283 | return (rc); |
284 | } |
285 | |
286 | /* --- @loadpub@ --- * |
287 | * |
288 | * Arguments: @dstr *d@ = string to write errors to |
289 | * |
290 | * Returns: Zero if OK, nonzero on error. |
291 | * |
292 | * Use: Reloads the public keyring. |
293 | */ |
294 | |
295 | static int loadpub(dstr *d) |
296 | { |
297 | key_file *kf = CREATE(key_file); |
298 | |
299 | if (key_open(kf, kr_pub, KOPEN_READ, keymoan, 0)) { |
300 | dstr_putf(d, "error reading public keyring `%s': %s", |
301 | kr_pub, strerror(errno)); |
302 | DESTROY(kf); |
303 | return (-1); |
304 | } |
305 | kf_pub = kf; |
306 | T( trace(T_KEYMGMT, "keymgmt: loaded public keyring `%s'", kr_pub); ) |
307 | return (0); |
308 | } |
309 | |
310 | /* --- @km_interval@ --- * |
311 | * |
312 | * Arguments: --- |
313 | * |
314 | * Returns: Zero if OK, nonzero to force reloading of keys. |
315 | * |
316 | * Use: Called on the interval timer to perform various useful jobs. |
317 | */ |
318 | |
319 | int km_interval(void) |
320 | { |
321 | dstr d = DSTR_INIT; |
410c8acf |
322 | key_file *kf; |
323 | int reload = 0; |
324 | |
325 | /* --- Check the private key first --- */ |
326 | |
327 | if (fwatch_update(&w_priv, kr_priv)) { |
328 | T( trace(T_KEYMGMT, "keymgmt: private keyring updated: reloading..."); ) |
329 | DRESET(&d); |
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330 | if (loadpriv(&d)) |
410c8acf |
331 | a_warn("%s -- ignoring changes", d.buf); |
52c03a2a |
332 | else |
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333 | reload = 1; |
410c8acf |
334 | } |
335 | |
336 | /* --- Now check the public keys --- */ |
337 | |
338 | if (fwatch_update(&w_pub, kr_pub)) { |
339 | T( trace(T_KEYMGMT, "keymgmt: public keyring updated: reloading..."); ) |
340 | kf = kf_pub; |
341 | DRESET(&d); |
342 | if (loadpub(&d)) |
343 | a_warn("%s -- ignoring changes", d.buf); |
344 | else { |
345 | reload = 1; |
346 | key_close(kf); |
347 | DESTROY(kf); |
348 | } |
349 | } |
350 | |
351 | /* --- Done --- */ |
352 | |
353 | return (reload); |
354 | } |
355 | |
356 | /* --- @km_init@ --- * |
357 | * |
358 | * Arguments: @const char *priv@ = private keyring file |
359 | * @const char *pub@ = public keyring file |
360 | * @const char *tag@ = tag to load |
361 | * |
362 | * Returns: --- |
363 | * |
364 | * Use: Initializes, and loads the private key. |
365 | */ |
366 | |
367 | void km_init(const char *priv, const char *pub, const char *tag) |
368 | { |
369 | dstr d = DSTR_INIT; |
370 | |
371 | kr_priv = priv; |
372 | kr_pub = pub; |
373 | tag_priv = tag; |
374 | fwatch_init(&w_priv, kr_priv); |
375 | fwatch_init(&w_pub, kr_pub); |
376 | |
377 | DRESET(&d); |
52c03a2a |
378 | if (loadpriv(&d)) |
410c8acf |
379 | die(EXIT_FAILURE, "%s", d.buf); |
410c8acf |
380 | if (loadpub(&d)) |
381 | die(EXIT_FAILURE, "%s", d.buf); |
382 | } |
383 | |
384 | /* --- @km_getpubkey@ --- * |
385 | * |
386 | * Arguments: @const char *tag@ = public key tag to load |
52c03a2a |
387 | * @ge *kpub@ = where to put the public key |
00e64b67 |
388 | * @time_t *t_exp@ = where to put the expiry time |
410c8acf |
389 | * |
390 | * Returns: Zero if OK, nonzero if it failed. |
391 | * |
392 | * Use: Fetches a public key from the keyring. |
393 | */ |
394 | |
52c03a2a |
395 | int km_getpubkey(const char *tag, ge *kpub, time_t *t_exp) |
410c8acf |
396 | { |
00e64b67 |
397 | key *k; |
52c03a2a |
398 | key_data *kd; |
399 | dstr t = DSTR_INIT; |
400 | const kgops **ko; |
401 | const char *e; |
402 | group *g = 0; |
403 | ge *p = 0; |
404 | int rc = -1; |
405 | |
406 | /* --- Find the key --- */ |
407 | |
408 | if (key_qtag(kf_pub, tag, &t, &k, &kd)) { |
409 | a_warn("private key `%s' not found in keyring `%s'", tag_priv, kr_priv); |
410 | goto done; |
411 | } |
410c8acf |
412 | |
52c03a2a |
413 | /* --- Look up the key type in the table --- */ |
414 | |
415 | for (ko = kgtab; *ko; ko++) { |
416 | if (strcmp((*ko)->ty, k->type) == 0) |
417 | goto tymatch; |
418 | } |
419 | a_warn("public key `%s' has unknown type `%s'", t.buf, k->type); |
420 | goto done; |
421 | tymatch:; |
422 | |
423 | /* --- Load the key --- */ |
424 | |
425 | if ((e = (*ko)->loadpub(kd, &g, &p, &t)) != 0) { |
426 | a_warn("error reading public key `%s': %s", t.buf, e); |
427 | goto done; |
428 | } |
429 | |
430 | /* --- Ensure that the group is correct --- * |
431 | * |
432 | * Dodginess! We assume that if this works, our global group is willing to |
433 | * adopt this public element. Probably reasonable. |
434 | */ |
435 | |
436 | if (!group_samep(gg, g)) { |
437 | a_warn("public key `%s' has incorrect group", t.buf); |
438 | goto done; |
439 | } |
440 | |
441 | /* --- Check the public group element --- */ |
442 | |
443 | if (group_check(gg, p)) { |
444 | a_warn("public key `%s' has bad public group element", t.buf); |
445 | goto done; |
410c8acf |
446 | } |
52c03a2a |
447 | |
448 | /* --- Dump the public key --- */ |
449 | |
410c8acf |
450 | IF_TRACING(T_KEYMGMT, { |
52c03a2a |
451 | trace(T_KEYMGMT, "keymgmt: extracted public key `%s'", t.buf); |
452 | trace(T_CRYPTO, "crypto: p = %s", gestr(gg, p)); |
410c8acf |
453 | }) |
52c03a2a |
454 | |
455 | /* --- OK, accept the public key --- */ |
456 | |
00e64b67 |
457 | *t_exp = k->exp; |
52c03a2a |
458 | G_COPY(gg, kpub, p); |
459 | rc = 0; |
460 | |
461 | /* --- Tidy up --- */ |
462 | |
463 | done: |
464 | if (p) G_DESTROY(g, p); |
465 | if (g) G_DESTROYGROUP(g); |
466 | dstr_destroy(&t); |
467 | return (rc); |
410c8acf |
468 | } |
469 | |
470 | /*----- That's all, folks -------------------------------------------------*/ |