Annotation of src/usr.bin/ssh/krl.c, Revision 1.49
1.1 djm 1: /*
2: * Copyright (c) 2012 Damien Miller <djm@mindrot.org>
3: *
4: * Permission to use, copy, modify, and distribute this software for any
5: * purpose with or without fee is hereby granted, provided that the above
6: * copyright notice and this permission notice appear in all copies.
7: *
8: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15: */
16:
1.49 ! djm 17: /* $OpenBSD: krl.c,v 1.48 2020/04/03 02:26:56 djm Exp $ */
1.2 djm 18:
1.1 djm 19: #include <sys/types.h>
20: #include <sys/tree.h>
21: #include <sys/queue.h>
22:
23: #include <errno.h>
24: #include <fcntl.h>
25: #include <limits.h>
26: #include <string.h>
27: #include <time.h>
28: #include <unistd.h>
1.44 djm 29: #include <stdlib.h>
1.1 djm 30:
1.20 djm 31: #include "sshbuf.h"
1.25 djm 32: #include "ssherr.h"
1.20 djm 33: #include "sshkey.h"
1.1 djm 34: #include "authfile.h"
35: #include "misc.h"
36: #include "log.h"
1.21 djm 37: #include "digest.h"
1.26 djm 38: #include "bitmap.h"
1.48 djm 39: #include "utf8.h"
1.1 djm 40:
41: #include "krl.h"
42:
43: /* #define DEBUG_KRL */
44: #ifdef DEBUG_KRL
45: # define KRL_DBG(x) debug3 x
46: #else
47: # define KRL_DBG(x)
48: #endif
49:
50: /*
51: * Trees of revoked serial numbers, key IDs and keys. This allows
52: * quick searching, querying and producing lists in canonical order.
53: */
54:
55: /* Tree of serial numbers. XXX make smarter: really need a real sparse bitmap */
56: struct revoked_serial {
57: u_int64_t lo, hi;
58: RB_ENTRY(revoked_serial) tree_entry;
59: };
60: static int serial_cmp(struct revoked_serial *a, struct revoked_serial *b);
61: RB_HEAD(revoked_serial_tree, revoked_serial);
62: RB_GENERATE_STATIC(revoked_serial_tree, revoked_serial, tree_entry, serial_cmp);
63:
64: /* Tree of key IDs */
65: struct revoked_key_id {
66: char *key_id;
67: RB_ENTRY(revoked_key_id) tree_entry;
68: };
69: static int key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b);
70: RB_HEAD(revoked_key_id_tree, revoked_key_id);
71: RB_GENERATE_STATIC(revoked_key_id_tree, revoked_key_id, tree_entry, key_id_cmp);
72:
73: /* Tree of blobs (used for keys and fingerprints) */
74: struct revoked_blob {
75: u_char *blob;
1.20 djm 76: size_t len;
1.1 djm 77: RB_ENTRY(revoked_blob) tree_entry;
78: };
79: static int blob_cmp(struct revoked_blob *a, struct revoked_blob *b);
80: RB_HEAD(revoked_blob_tree, revoked_blob);
81: RB_GENERATE_STATIC(revoked_blob_tree, revoked_blob, tree_entry, blob_cmp);
82:
83: /* Tracks revoked certs for a single CA */
84: struct revoked_certs {
1.20 djm 85: struct sshkey *ca_key;
1.1 djm 86: struct revoked_serial_tree revoked_serials;
87: struct revoked_key_id_tree revoked_key_ids;
88: TAILQ_ENTRY(revoked_certs) entry;
89: };
90: TAILQ_HEAD(revoked_certs_list, revoked_certs);
91:
92: struct ssh_krl {
93: u_int64_t krl_version;
94: u_int64_t generated_date;
95: u_int64_t flags;
96: char *comment;
97: struct revoked_blob_tree revoked_keys;
98: struct revoked_blob_tree revoked_sha1s;
1.42 djm 99: struct revoked_blob_tree revoked_sha256s;
1.1 djm 100: struct revoked_certs_list revoked_certs;
101: };
102:
103: /* Return equal if a and b overlap */
104: static int
105: serial_cmp(struct revoked_serial *a, struct revoked_serial *b)
106: {
107: if (a->hi >= b->lo && a->lo <= b->hi)
108: return 0;
109: return a->lo < b->lo ? -1 : 1;
110: }
111:
112: static int
113: key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b)
114: {
115: return strcmp(a->key_id, b->key_id);
116: }
117:
118: static int
119: blob_cmp(struct revoked_blob *a, struct revoked_blob *b)
120: {
121: int r;
122:
123: if (a->len != b->len) {
1.38 deraadt 124: if ((r = memcmp(a->blob, b->blob, MINIMUM(a->len, b->len))) != 0)
1.1 djm 125: return r;
126: return a->len > b->len ? 1 : -1;
127: } else
128: return memcmp(a->blob, b->blob, a->len);
129: }
130:
131: struct ssh_krl *
132: ssh_krl_init(void)
133: {
134: struct ssh_krl *krl;
135:
136: if ((krl = calloc(1, sizeof(*krl))) == NULL)
137: return NULL;
138: RB_INIT(&krl->revoked_keys);
139: RB_INIT(&krl->revoked_sha1s);
1.42 djm 140: RB_INIT(&krl->revoked_sha256s);
1.1 djm 141: TAILQ_INIT(&krl->revoked_certs);
142: return krl;
143: }
144:
145: static void
146: revoked_certs_free(struct revoked_certs *rc)
147: {
148: struct revoked_serial *rs, *trs;
149: struct revoked_key_id *rki, *trki;
150:
151: RB_FOREACH_SAFE(rs, revoked_serial_tree, &rc->revoked_serials, trs) {
152: RB_REMOVE(revoked_serial_tree, &rc->revoked_serials, rs);
153: free(rs);
154: }
155: RB_FOREACH_SAFE(rki, revoked_key_id_tree, &rc->revoked_key_ids, trki) {
156: RB_REMOVE(revoked_key_id_tree, &rc->revoked_key_ids, rki);
157: free(rki->key_id);
158: free(rki);
159: }
1.31 djm 160: sshkey_free(rc->ca_key);
1.1 djm 161: }
162:
163: void
164: ssh_krl_free(struct ssh_krl *krl)
165: {
166: struct revoked_blob *rb, *trb;
167: struct revoked_certs *rc, *trc;
168:
169: if (krl == NULL)
170: return;
171:
172: free(krl->comment);
173: RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_keys, trb) {
174: RB_REMOVE(revoked_blob_tree, &krl->revoked_keys, rb);
175: free(rb->blob);
176: free(rb);
177: }
178: RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha1s, trb) {
179: RB_REMOVE(revoked_blob_tree, &krl->revoked_sha1s, rb);
180: free(rb->blob);
181: free(rb);
182: }
1.42 djm 183: RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha256s, trb) {
184: RB_REMOVE(revoked_blob_tree, &krl->revoked_sha256s, rb);
185: free(rb->blob);
186: free(rb);
187: }
1.1 djm 188: TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) {
189: TAILQ_REMOVE(&krl->revoked_certs, rc, entry);
190: revoked_certs_free(rc);
191: }
192: }
193:
194: void
195: ssh_krl_set_version(struct ssh_krl *krl, u_int64_t version)
196: {
197: krl->krl_version = version;
198: }
199:
1.20 djm 200: int
1.1 djm 201: ssh_krl_set_comment(struct ssh_krl *krl, const char *comment)
202: {
203: free(krl->comment);
204: if ((krl->comment = strdup(comment)) == NULL)
1.20 djm 205: return SSH_ERR_ALLOC_FAIL;
206: return 0;
1.1 djm 207: }
208:
209: /*
210: * Find the revoked_certs struct for a CA key. If allow_create is set then
211: * create a new one in the tree if one did not exist already.
212: */
213: static int
1.20 djm 214: revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
1.1 djm 215: struct revoked_certs **rcp, int allow_create)
216: {
217: struct revoked_certs *rc;
1.20 djm 218: int r;
1.1 djm 219:
220: *rcp = NULL;
221: TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
1.31 djm 222: if ((ca_key == NULL && rc->ca_key == NULL) ||
223: sshkey_equal(rc->ca_key, ca_key)) {
1.1 djm 224: *rcp = rc;
225: return 0;
226: }
227: }
228: if (!allow_create)
229: return 0;
230: /* If this CA doesn't exist in the list then add it now */
231: if ((rc = calloc(1, sizeof(*rc))) == NULL)
1.20 djm 232: return SSH_ERR_ALLOC_FAIL;
1.31 djm 233: if (ca_key == NULL)
234: rc->ca_key = NULL;
235: else if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
1.1 djm 236: free(rc);
1.20 djm 237: return r;
1.1 djm 238: }
239: RB_INIT(&rc->revoked_serials);
240: RB_INIT(&rc->revoked_key_ids);
241: TAILQ_INSERT_TAIL(&krl->revoked_certs, rc, entry);
1.31 djm 242: KRL_DBG(("%s: new CA %s", __func__,
243: ca_key == NULL ? "*" : sshkey_type(ca_key)));
1.1 djm 244: *rcp = rc;
245: return 0;
246: }
247:
248: static int
249: insert_serial_range(struct revoked_serial_tree *rt, u_int64_t lo, u_int64_t hi)
250: {
251: struct revoked_serial rs, *ers, *crs, *irs;
252:
253: KRL_DBG(("%s: insert %llu:%llu", __func__, lo, hi));
1.14 tedu 254: memset(&rs, 0, sizeof(rs));
1.1 djm 255: rs.lo = lo;
256: rs.hi = hi;
257: ers = RB_NFIND(revoked_serial_tree, rt, &rs);
258: if (ers == NULL || serial_cmp(ers, &rs) != 0) {
259: /* No entry matches. Just insert */
260: if ((irs = malloc(sizeof(rs))) == NULL)
1.20 djm 261: return SSH_ERR_ALLOC_FAIL;
1.1 djm 262: memcpy(irs, &rs, sizeof(*irs));
263: ers = RB_INSERT(revoked_serial_tree, rt, irs);
264: if (ers != NULL) {
265: KRL_DBG(("%s: bad: ers != NULL", __func__));
266: /* Shouldn't happen */
1.4 markus 267: free(irs);
1.25 djm 268: return SSH_ERR_INTERNAL_ERROR;
1.1 djm 269: }
270: ers = irs;
271: } else {
272: KRL_DBG(("%s: overlap found %llu:%llu", __func__,
273: ers->lo, ers->hi));
274: /*
275: * The inserted entry overlaps an existing one. Grow the
276: * existing entry.
277: */
278: if (ers->lo > lo)
279: ers->lo = lo;
280: if (ers->hi < hi)
281: ers->hi = hi;
282: }
1.25 djm 283:
1.1 djm 284: /*
285: * The inserted or revised range might overlap or abut adjacent ones;
286: * coalesce as necessary.
287: */
288:
289: /* Check predecessors */
290: while ((crs = RB_PREV(revoked_serial_tree, rt, ers)) != NULL) {
291: KRL_DBG(("%s: pred %llu:%llu", __func__, crs->lo, crs->hi));
292: if (ers->lo != 0 && crs->hi < ers->lo - 1)
293: break;
294: /* This entry overlaps. */
295: if (crs->lo < ers->lo) {
296: ers->lo = crs->lo;
297: KRL_DBG(("%s: pred extend %llu:%llu", __func__,
298: ers->lo, ers->hi));
299: }
300: RB_REMOVE(revoked_serial_tree, rt, crs);
301: free(crs);
302: }
303: /* Check successors */
304: while ((crs = RB_NEXT(revoked_serial_tree, rt, ers)) != NULL) {
305: KRL_DBG(("%s: succ %llu:%llu", __func__, crs->lo, crs->hi));
306: if (ers->hi != (u_int64_t)-1 && crs->lo > ers->hi + 1)
307: break;
308: /* This entry overlaps. */
309: if (crs->hi > ers->hi) {
310: ers->hi = crs->hi;
311: KRL_DBG(("%s: succ extend %llu:%llu", __func__,
312: ers->lo, ers->hi));
313: }
314: RB_REMOVE(revoked_serial_tree, rt, crs);
315: free(crs);
316: }
317: KRL_DBG(("%s: done, final %llu:%llu", __func__, ers->lo, ers->hi));
318: return 0;
319: }
320:
321: int
1.20 djm 322: ssh_krl_revoke_cert_by_serial(struct ssh_krl *krl, const struct sshkey *ca_key,
1.1 djm 323: u_int64_t serial)
324: {
325: return ssh_krl_revoke_cert_by_serial_range(krl, ca_key, serial, serial);
326: }
327:
328: int
1.25 djm 329: ssh_krl_revoke_cert_by_serial_range(struct ssh_krl *krl,
330: const struct sshkey *ca_key, u_int64_t lo, u_int64_t hi)
1.1 djm 331: {
332: struct revoked_certs *rc;
1.20 djm 333: int r;
1.1 djm 334:
335: if (lo > hi || lo == 0)
1.25 djm 336: return SSH_ERR_INVALID_ARGUMENT;
1.20 djm 337: if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
338: return r;
1.1 djm 339: return insert_serial_range(&rc->revoked_serials, lo, hi);
340: }
341:
342: int
1.20 djm 343: ssh_krl_revoke_cert_by_key_id(struct ssh_krl *krl, const struct sshkey *ca_key,
1.1 djm 344: const char *key_id)
345: {
346: struct revoked_key_id *rki, *erki;
347: struct revoked_certs *rc;
1.20 djm 348: int r;
1.1 djm 349:
1.20 djm 350: if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
351: return r;
1.1 djm 352:
1.25 djm 353: KRL_DBG(("%s: revoke %s", __func__, key_id));
1.1 djm 354: if ((rki = calloc(1, sizeof(*rki))) == NULL ||
355: (rki->key_id = strdup(key_id)) == NULL) {
356: free(rki);
1.20 djm 357: return SSH_ERR_ALLOC_FAIL;
1.1 djm 358: }
359: erki = RB_INSERT(revoked_key_id_tree, &rc->revoked_key_ids, rki);
360: if (erki != NULL) {
361: free(rki->key_id);
362: free(rki);
363: }
364: return 0;
365: }
366:
367: /* Convert "key" to a public key blob without any certificate information */
368: static int
1.20 djm 369: plain_key_blob(const struct sshkey *key, u_char **blob, size_t *blen)
1.1 djm 370: {
1.20 djm 371: struct sshkey *kcopy;
1.1 djm 372: int r;
373:
1.20 djm 374: if ((r = sshkey_from_private(key, &kcopy)) != 0)
375: return r;
376: if (sshkey_is_cert(kcopy)) {
377: if ((r = sshkey_drop_cert(kcopy)) != 0) {
378: sshkey_free(kcopy);
379: return r;
1.1 djm 380: }
381: }
1.20 djm 382: r = sshkey_to_blob(kcopy, blob, blen);
1.23 markus 383: sshkey_free(kcopy);
1.17 djm 384: return r;
1.1 djm 385: }
386:
387: /* Revoke a key blob. Ownership of blob is transferred to the tree */
388: static int
1.25 djm 389: revoke_blob(struct revoked_blob_tree *rbt, u_char *blob, size_t len)
1.1 djm 390: {
391: struct revoked_blob *rb, *erb;
392:
393: if ((rb = calloc(1, sizeof(*rb))) == NULL)
1.20 djm 394: return SSH_ERR_ALLOC_FAIL;
1.1 djm 395: rb->blob = blob;
396: rb->len = len;
397: erb = RB_INSERT(revoked_blob_tree, rbt, rb);
398: if (erb != NULL) {
399: free(rb->blob);
400: free(rb);
401: }
402: return 0;
403: }
404:
405: int
1.20 djm 406: ssh_krl_revoke_key_explicit(struct ssh_krl *krl, const struct sshkey *key)
1.1 djm 407: {
408: u_char *blob;
1.20 djm 409: size_t len;
410: int r;
1.1 djm 411:
1.20 djm 412: debug3("%s: revoke type %s", __func__, sshkey_type(key));
413: if ((r = plain_key_blob(key, &blob, &len)) != 0)
414: return r;
1.1 djm 415: return revoke_blob(&krl->revoked_keys, blob, len);
416: }
417:
1.42 djm 418: static int
419: revoke_by_hash(struct revoked_blob_tree *target, const u_char *p, size_t len)
1.1 djm 420: {
421: u_char *blob;
1.20 djm 422: int r;
1.1 djm 423:
1.42 djm 424: /* need to copy hash, as revoke_blob steals ownership */
425: if ((blob = malloc(len)) == NULL)
426: return SSH_ERR_SYSTEM_ERROR;
427: memcpy(blob, p, len);
428: if ((r = revoke_blob(target, blob, len)) != 0) {
429: free(blob);
1.20 djm 430: return r;
1.42 djm 431: }
432: return 0;
433: }
434:
435: int
436: ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const u_char *p, size_t len)
437: {
438: debug3("%s: revoke by sha1", __func__);
439: if (len != 20)
440: return SSH_ERR_INVALID_FORMAT;
441: return revoke_by_hash(&krl->revoked_sha1s, p, len);
442: }
443:
444: int
445: ssh_krl_revoke_key_sha256(struct ssh_krl *krl, const u_char *p, size_t len)
446: {
447: debug3("%s: revoke by sha256", __func__);
448: if (len != 32)
449: return SSH_ERR_INVALID_FORMAT;
450: return revoke_by_hash(&krl->revoked_sha256s, p, len);
1.1 djm 451: }
452:
453: int
1.20 djm 454: ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key)
1.1 djm 455: {
1.42 djm 456: /* XXX replace with SHA256? */
1.20 djm 457: if (!sshkey_is_cert(key))
1.42 djm 458: return ssh_krl_revoke_key_explicit(krl, key);
1.1 djm 459:
1.33 djm 460: if (key->cert->serial == 0) {
1.1 djm 461: return ssh_krl_revoke_cert_by_key_id(krl,
462: key->cert->signature_key,
463: key->cert->key_id);
464: } else {
465: return ssh_krl_revoke_cert_by_serial(krl,
466: key->cert->signature_key,
467: key->cert->serial);
468: }
469: }
470:
471: /*
1.20 djm 472: * Select the most compact section type to emit next in a KRL based on
473: * the current section type, the run length of contiguous revoked serial
1.1 djm 474: * numbers and the gaps from the last and to the next revoked serial.
475: * Applies a mostly-accurate bit cost model to select the section type
476: * that will minimise the size of the resultant KRL.
477: */
478: static int
479: choose_next_state(int current_state, u_int64_t contig, int final,
480: u_int64_t last_gap, u_int64_t next_gap, int *force_new_section)
481: {
482: int new_state;
483: u_int64_t cost, cost_list, cost_range, cost_bitmap, cost_bitmap_restart;
484:
485: /*
486: * Avoid unsigned overflows.
487: * The limits are high enough to avoid confusing the calculations.
488: */
1.38 deraadt 489: contig = MINIMUM(contig, 1ULL<<31);
490: last_gap = MINIMUM(last_gap, 1ULL<<31);
491: next_gap = MINIMUM(next_gap, 1ULL<<31);
1.1 djm 492:
493: /*
494: * Calculate the cost to switch from the current state to candidates.
495: * NB. range sections only ever contain a single range, so their
496: * switching cost is independent of the current_state.
497: */
498: cost_list = cost_bitmap = cost_bitmap_restart = 0;
499: cost_range = 8;
500: switch (current_state) {
501: case KRL_SECTION_CERT_SERIAL_LIST:
502: cost_bitmap_restart = cost_bitmap = 8 + 64;
503: break;
504: case KRL_SECTION_CERT_SERIAL_BITMAP:
505: cost_list = 8;
506: cost_bitmap_restart = 8 + 64;
507: break;
508: case KRL_SECTION_CERT_SERIAL_RANGE:
509: case 0:
510: cost_bitmap_restart = cost_bitmap = 8 + 64;
511: cost_list = 8;
512: }
513:
514: /* Estimate base cost in bits of each section type */
515: cost_list += 64 * contig + (final ? 0 : 8+64);
516: cost_range += (2 * 64) + (final ? 0 : 8+64);
1.38 deraadt 517: cost_bitmap += last_gap + contig + (final ? 0 : MINIMUM(next_gap, 8+64));
518: cost_bitmap_restart += contig + (final ? 0 : MINIMUM(next_gap, 8+64));
1.1 djm 519:
520: /* Convert to byte costs for actual comparison */
521: cost_list = (cost_list + 7) / 8;
522: cost_bitmap = (cost_bitmap + 7) / 8;
523: cost_bitmap_restart = (cost_bitmap_restart + 7) / 8;
524: cost_range = (cost_range + 7) / 8;
525:
526: /* Now pick the best choice */
527: *force_new_section = 0;
528: new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
529: cost = cost_bitmap;
530: if (cost_range < cost) {
531: new_state = KRL_SECTION_CERT_SERIAL_RANGE;
532: cost = cost_range;
533: }
534: if (cost_list < cost) {
535: new_state = KRL_SECTION_CERT_SERIAL_LIST;
536: cost = cost_list;
537: }
538: if (cost_bitmap_restart < cost) {
539: new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
540: *force_new_section = 1;
541: cost = cost_bitmap_restart;
542: }
1.25 djm 543: KRL_DBG(("%s: contig %llu last_gap %llu next_gap %llu final %d, costs:"
1.1 djm 544: "list %llu range %llu bitmap %llu new bitmap %llu, "
1.11 djm 545: "selected 0x%02x%s", __func__, (long long unsigned)contig,
546: (long long unsigned)last_gap, (long long unsigned)next_gap, final,
547: (long long unsigned)cost_list, (long long unsigned)cost_range,
548: (long long unsigned)cost_bitmap,
549: (long long unsigned)cost_bitmap_restart, new_state,
1.25 djm 550: *force_new_section ? " restart" : ""));
1.1 djm 551: return new_state;
552: }
553:
1.26 djm 554: static int
555: put_bitmap(struct sshbuf *buf, struct bitmap *bitmap)
556: {
557: size_t len;
558: u_char *blob;
559: int r;
560:
561: len = bitmap_nbytes(bitmap);
562: if ((blob = malloc(len)) == NULL)
563: return SSH_ERR_ALLOC_FAIL;
564: if (bitmap_to_string(bitmap, blob, len) != 0) {
565: free(blob);
566: return SSH_ERR_INTERNAL_ERROR;
567: }
568: r = sshbuf_put_bignum2_bytes(buf, blob, len);
569: free(blob);
570: return r;
571: }
572:
1.1 djm 573: /* Generate a KRL_SECTION_CERTIFICATES KRL section */
574: static int
1.20 djm 575: revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
1.1 djm 576: {
1.25 djm 577: int final, force_new_sect, r = SSH_ERR_INTERNAL_ERROR;
1.1 djm 578: u_int64_t i, contig, gap, last = 0, bitmap_start = 0;
579: struct revoked_serial *rs, *nrs;
580: struct revoked_key_id *rki;
581: int next_state, state = 0;
1.20 djm 582: struct sshbuf *sect;
1.26 djm 583: struct bitmap *bitmap = NULL;
1.1 djm 584:
1.20 djm 585: if ((sect = sshbuf_new()) == NULL)
586: return SSH_ERR_ALLOC_FAIL;
1.1 djm 587:
1.31 djm 588: /* Store the header: optional CA scope key, reserved */
589: if (rc->ca_key == NULL) {
590: if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
591: goto out;
592: } else {
593: if ((r = sshkey_puts(rc->ca_key, buf)) != 0)
594: goto out;
595: }
596: if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
1.20 djm 597: goto out;
1.1 djm 598:
599: /* Store the revoked serials. */
600: for (rs = RB_MIN(revoked_serial_tree, &rc->revoked_serials);
601: rs != NULL;
602: rs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs)) {
1.25 djm 603: KRL_DBG(("%s: serial %llu:%llu state 0x%02x", __func__,
1.11 djm 604: (long long unsigned)rs->lo, (long long unsigned)rs->hi,
1.25 djm 605: state));
1.1 djm 606:
607: /* Check contiguous length and gap to next section (if any) */
608: nrs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs);
609: final = nrs == NULL;
610: gap = nrs == NULL ? 0 : nrs->lo - rs->hi;
611: contig = 1 + (rs->hi - rs->lo);
612:
613: /* Choose next state based on these */
614: next_state = choose_next_state(state, contig, final,
615: state == 0 ? 0 : rs->lo - last, gap, &force_new_sect);
616:
617: /*
618: * If the current section is a range section or has a different
619: * type to the next section, then finish it off now.
620: */
621: if (state != 0 && (force_new_sect || next_state != state ||
622: state == KRL_SECTION_CERT_SERIAL_RANGE)) {
1.25 djm 623: KRL_DBG(("%s: finish state 0x%02x", __func__, state));
1.1 djm 624: switch (state) {
625: case KRL_SECTION_CERT_SERIAL_LIST:
626: case KRL_SECTION_CERT_SERIAL_RANGE:
627: break;
628: case KRL_SECTION_CERT_SERIAL_BITMAP:
1.26 djm 629: if ((r = put_bitmap(sect, bitmap)) != 0)
1.20 djm 630: goto out;
1.26 djm 631: bitmap_free(bitmap);
1.1 djm 632: bitmap = NULL;
633: break;
634: }
1.20 djm 635: if ((r = sshbuf_put_u8(buf, state)) != 0 ||
636: (r = sshbuf_put_stringb(buf, sect)) != 0)
637: goto out;
638: sshbuf_reset(sect);
1.1 djm 639: }
640:
641: /* If we are starting a new section then prepare it now */
642: if (next_state != state || force_new_sect) {
1.25 djm 643: KRL_DBG(("%s: start state 0x%02x", __func__,
644: next_state));
1.1 djm 645: state = next_state;
1.20 djm 646: sshbuf_reset(sect);
1.1 djm 647: switch (state) {
648: case KRL_SECTION_CERT_SERIAL_LIST:
649: case KRL_SECTION_CERT_SERIAL_RANGE:
650: break;
651: case KRL_SECTION_CERT_SERIAL_BITMAP:
1.26 djm 652: if ((bitmap = bitmap_new()) == NULL) {
1.20 djm 653: r = SSH_ERR_ALLOC_FAIL;
1.1 djm 654: goto out;
1.20 djm 655: }
1.1 djm 656: bitmap_start = rs->lo;
1.20 djm 657: if ((r = sshbuf_put_u64(sect,
658: bitmap_start)) != 0)
659: goto out;
1.1 djm 660: break;
661: }
662: }
663:
664: /* Perform section-specific processing */
665: switch (state) {
666: case KRL_SECTION_CERT_SERIAL_LIST:
1.20 djm 667: for (i = 0; i < contig; i++) {
668: if ((r = sshbuf_put_u64(sect, rs->lo + i)) != 0)
669: goto out;
670: }
1.1 djm 671: break;
672: case KRL_SECTION_CERT_SERIAL_RANGE:
1.20 djm 673: if ((r = sshbuf_put_u64(sect, rs->lo)) != 0 ||
674: (r = sshbuf_put_u64(sect, rs->hi)) != 0)
675: goto out;
1.1 djm 676: break;
677: case KRL_SECTION_CERT_SERIAL_BITMAP:
678: if (rs->lo - bitmap_start > INT_MAX) {
679: error("%s: insane bitmap gap", __func__);
680: goto out;
681: }
682: for (i = 0; i < contig; i++) {
1.26 djm 683: if (bitmap_set_bit(bitmap,
684: rs->lo + i - bitmap_start) != 0) {
1.20 djm 685: r = SSH_ERR_ALLOC_FAIL;
1.1 djm 686: goto out;
1.20 djm 687: }
1.1 djm 688: }
689: break;
690: }
691: last = rs->hi;
692: }
693: /* Flush the remaining section, if any */
694: if (state != 0) {
1.25 djm 695: KRL_DBG(("%s: serial final flush for state 0x%02x",
696: __func__, state));
1.1 djm 697: switch (state) {
698: case KRL_SECTION_CERT_SERIAL_LIST:
699: case KRL_SECTION_CERT_SERIAL_RANGE:
700: break;
701: case KRL_SECTION_CERT_SERIAL_BITMAP:
1.26 djm 702: if ((r = put_bitmap(sect, bitmap)) != 0)
1.20 djm 703: goto out;
1.26 djm 704: bitmap_free(bitmap);
1.1 djm 705: bitmap = NULL;
706: break;
707: }
1.20 djm 708: if ((r = sshbuf_put_u8(buf, state)) != 0 ||
709: (r = sshbuf_put_stringb(buf, sect)) != 0)
710: goto out;
1.1 djm 711: }
1.25 djm 712: KRL_DBG(("%s: serial done ", __func__));
1.1 djm 713:
714: /* Now output a section for any revocations by key ID */
1.20 djm 715: sshbuf_reset(sect);
1.1 djm 716: RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) {
1.25 djm 717: KRL_DBG(("%s: key ID %s", __func__, rki->key_id));
1.20 djm 718: if ((r = sshbuf_put_cstring(sect, rki->key_id)) != 0)
719: goto out;
1.1 djm 720: }
1.20 djm 721: if (sshbuf_len(sect) != 0) {
722: if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERT_KEY_ID)) != 0 ||
723: (r = sshbuf_put_stringb(buf, sect)) != 0)
724: goto out;
1.1 djm 725: }
726: r = 0;
727: out:
1.26 djm 728: bitmap_free(bitmap);
1.20 djm 729: sshbuf_free(sect);
1.1 djm 730: return r;
731: }
732:
733: int
1.20 djm 734: ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf,
1.43 djm 735: struct sshkey **sign_keys, u_int nsign_keys)
1.1 djm 736: {
1.25 djm 737: int r = SSH_ERR_INTERNAL_ERROR;
1.1 djm 738: struct revoked_certs *rc;
739: struct revoked_blob *rb;
1.20 djm 740: struct sshbuf *sect;
741: u_char *sblob = NULL;
742: size_t slen, i;
1.1 djm 743:
744: if (krl->generated_date == 0)
745: krl->generated_date = time(NULL);
746:
1.20 djm 747: if ((sect = sshbuf_new()) == NULL)
748: return SSH_ERR_ALLOC_FAIL;
1.1 djm 749:
750: /* Store the header */
1.20 djm 751: if ((r = sshbuf_put(buf, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0 ||
752: (r = sshbuf_put_u32(buf, KRL_FORMAT_VERSION)) != 0 ||
753: (r = sshbuf_put_u64(buf, krl->krl_version)) != 0 ||
1.34 jsg 754: (r = sshbuf_put_u64(buf, krl->generated_date)) != 0 ||
1.20 djm 755: (r = sshbuf_put_u64(buf, krl->flags)) != 0 ||
756: (r = sshbuf_put_string(buf, NULL, 0)) != 0 ||
757: (r = sshbuf_put_cstring(buf, krl->comment)) != 0)
758: goto out;
1.1 djm 759:
760: /* Store sections for revoked certificates */
761: TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
1.20 djm 762: sshbuf_reset(sect);
763: if ((r = revoked_certs_generate(rc, sect)) != 0)
764: goto out;
765: if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERTIFICATES)) != 0 ||
766: (r = sshbuf_put_stringb(buf, sect)) != 0)
1.1 djm 767: goto out;
768: }
769:
770: /* Finally, output sections for revocations by public key/hash */
1.20 djm 771: sshbuf_reset(sect);
1.1 djm 772: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) {
1.28 djm 773: KRL_DBG(("%s: key len %zu ", __func__, rb->len));
1.24 markus 774: if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
1.20 djm 775: goto out;
1.1 djm 776: }
1.20 djm 777: if (sshbuf_len(sect) != 0) {
778: if ((r = sshbuf_put_u8(buf, KRL_SECTION_EXPLICIT_KEY)) != 0 ||
779: (r = sshbuf_put_stringb(buf, sect)) != 0)
780: goto out;
1.1 djm 781: }
1.20 djm 782: sshbuf_reset(sect);
1.1 djm 783: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) {
1.28 djm 784: KRL_DBG(("%s: hash len %zu ", __func__, rb->len));
1.24 markus 785: if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
1.20 djm 786: goto out;
1.1 djm 787: }
1.20 djm 788: if (sshbuf_len(sect) != 0) {
789: if ((r = sshbuf_put_u8(buf,
790: KRL_SECTION_FINGERPRINT_SHA1)) != 0 ||
791: (r = sshbuf_put_stringb(buf, sect)) != 0)
792: goto out;
1.1 djm 793: }
1.42 djm 794: sshbuf_reset(sect);
795: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) {
796: KRL_DBG(("%s: hash len %zu ", __func__, rb->len));
797: if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
798: goto out;
799: }
800: if (sshbuf_len(sect) != 0) {
801: if ((r = sshbuf_put_u8(buf,
802: KRL_SECTION_FINGERPRINT_SHA256)) != 0 ||
803: (r = sshbuf_put_stringb(buf, sect)) != 0)
804: goto out;
805: }
1.1 djm 806:
807: for (i = 0; i < nsign_keys; i++) {
1.30 djm 808: KRL_DBG(("%s: signature key %s", __func__,
809: sshkey_ssh_name(sign_keys[i])));
1.20 djm 810: if ((r = sshbuf_put_u8(buf, KRL_SECTION_SIGNATURE)) != 0 ||
1.30 djm 811: (r = sshkey_puts(sign_keys[i], buf)) != 0)
1.20 djm 812: goto out;
1.1 djm 813:
1.20 djm 814: if ((r = sshkey_sign(sign_keys[i], &sblob, &slen,
1.45 djm 815: sshbuf_ptr(buf), sshbuf_len(buf), NULL, NULL, 0)) != 0)
1.20 djm 816: goto out;
1.28 djm 817: KRL_DBG(("%s: signature sig len %zu", __func__, slen));
1.20 djm 818: if ((r = sshbuf_put_string(buf, sblob, slen)) != 0)
1.1 djm 819: goto out;
820: }
821:
822: r = 0;
823: out:
824: free(sblob);
1.20 djm 825: sshbuf_free(sect);
1.1 djm 826: return r;
827: }
828:
829: static void
830: format_timestamp(u_int64_t timestamp, char *ts, size_t nts)
831: {
832: time_t t;
833: struct tm *tm;
834:
835: t = timestamp;
836: tm = localtime(&t);
1.19 djm 837: if (tm == NULL)
1.27 deraadt 838: strlcpy(ts, "<INVALID>", nts);
1.19 djm 839: else {
840: *ts = '\0';
841: strftime(ts, nts, "%Y%m%dT%H%M%S", tm);
842: }
1.1 djm 843: }
844:
845: static int
1.20 djm 846: parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
1.1 djm 847: {
1.26 djm 848: int r = SSH_ERR_INTERNAL_ERROR;
1.15 djm 849: u_char type;
850: const u_char *blob;
1.26 djm 851: size_t blen, nbits;
1.20 djm 852: struct sshbuf *subsect = NULL;
1.1 djm 853: u_int64_t serial, serial_lo, serial_hi;
1.26 djm 854: struct bitmap *bitmap = NULL;
1.1 djm 855: char *key_id = NULL;
1.20 djm 856: struct sshkey *ca_key = NULL;
1.1 djm 857:
1.20 djm 858: if ((subsect = sshbuf_new()) == NULL)
859: return SSH_ERR_ALLOC_FAIL;
1.1 djm 860:
1.20 djm 861: /* Header: key, reserved */
862: if ((r = sshbuf_get_string_direct(buf, &blob, &blen)) != 0 ||
863: (r = sshbuf_skip_string(buf)) != 0)
1.1 djm 864: goto out;
1.31 djm 865: if (blen != 0 && (r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
1.1 djm 866: goto out;
867:
1.20 djm 868: while (sshbuf_len(buf) > 0) {
1.36 mmcc 869: sshbuf_free(subsect);
870: subsect = NULL;
1.20 djm 871: if ((r = sshbuf_get_u8(buf, &type)) != 0 ||
872: (r = sshbuf_froms(buf, &subsect)) != 0)
1.1 djm 873: goto out;
1.25 djm 874: KRL_DBG(("%s: subsection type 0x%02x", __func__, type));
875: /* sshbuf_dump(subsect, stderr); */
1.1 djm 876:
877: switch (type) {
878: case KRL_SECTION_CERT_SERIAL_LIST:
1.20 djm 879: while (sshbuf_len(subsect) > 0) {
880: if ((r = sshbuf_get_u64(subsect, &serial)) != 0)
1.1 djm 881: goto out;
1.20 djm 882: if ((r = ssh_krl_revoke_cert_by_serial(krl,
883: ca_key, serial)) != 0)
1.1 djm 884: goto out;
885: }
886: break;
887: case KRL_SECTION_CERT_SERIAL_RANGE:
1.20 djm 888: if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
889: (r = sshbuf_get_u64(subsect, &serial_hi)) != 0)
1.1 djm 890: goto out;
1.20 djm 891: if ((r = ssh_krl_revoke_cert_by_serial_range(krl,
892: ca_key, serial_lo, serial_hi)) != 0)
1.1 djm 893: goto out;
894: break;
895: case KRL_SECTION_CERT_SERIAL_BITMAP:
1.26 djm 896: if ((bitmap = bitmap_new()) == NULL) {
1.20 djm 897: r = SSH_ERR_ALLOC_FAIL;
1.1 djm 898: goto out;
899: }
1.20 djm 900: if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
1.26 djm 901: (r = sshbuf_get_bignum2_bytes_direct(subsect,
902: &blob, &blen)) != 0)
1.1 djm 903: goto out;
1.26 djm 904: if (bitmap_from_string(bitmap, blob, blen) != 0) {
1.20 djm 905: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 906: goto out;
907: }
1.26 djm 908: nbits = bitmap_nbits(bitmap);
1.25 djm 909: for (serial = 0; serial < (u_int64_t)nbits; serial++) {
1.1 djm 910: if (serial > 0 && serial_lo + serial == 0) {
911: error("%s: bitmap wraps u64", __func__);
1.20 djm 912: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 913: goto out;
914: }
1.26 djm 915: if (!bitmap_test_bit(bitmap, serial))
1.1 djm 916: continue;
1.20 djm 917: if ((r = ssh_krl_revoke_cert_by_serial(krl,
918: ca_key, serial_lo + serial)) != 0)
1.1 djm 919: goto out;
920: }
1.26 djm 921: bitmap_free(bitmap);
1.1 djm 922: bitmap = NULL;
923: break;
924: case KRL_SECTION_CERT_KEY_ID:
1.20 djm 925: while (sshbuf_len(subsect) > 0) {
926: if ((r = sshbuf_get_cstring(subsect,
927: &key_id, NULL)) != 0)
1.1 djm 928: goto out;
1.20 djm 929: if ((r = ssh_krl_revoke_cert_by_key_id(krl,
930: ca_key, key_id)) != 0)
1.1 djm 931: goto out;
932: free(key_id);
933: key_id = NULL;
934: }
935: break;
936: default:
937: error("Unsupported KRL certificate section %u", type);
1.20 djm 938: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 939: goto out;
940: }
1.20 djm 941: if (sshbuf_len(subsect) > 0) {
1.1 djm 942: error("KRL certificate section contains unparsed data");
1.20 djm 943: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 944: goto out;
945: }
946: }
947:
1.20 djm 948: r = 0;
1.1 djm 949: out:
950: if (bitmap != NULL)
1.26 djm 951: bitmap_free(bitmap);
1.1 djm 952: free(key_id);
1.20 djm 953: sshkey_free(ca_key);
954: sshbuf_free(subsect);
955: return r;
1.1 djm 956: }
957:
1.42 djm 958: static int
959: blob_section(struct sshbuf *sect, struct revoked_blob_tree *target_tree,
960: size_t expected_len)
961: {
962: u_char *rdata = NULL;
963: size_t rlen = 0;
964: int r;
965:
966: while (sshbuf_len(sect) > 0) {
967: if ((r = sshbuf_get_string(sect, &rdata, &rlen)) != 0)
968: return r;
969: if (expected_len != 0 && rlen != expected_len) {
970: error("%s: bad length", __func__);
971: free(rdata);
972: return SSH_ERR_INVALID_FORMAT;
973: }
974: if ((r = revoke_blob(target_tree, rdata, rlen)) != 0) {
975: free(rdata);
976: return r;
977: }
978: }
979: return 0;
980: }
1.1 djm 981:
982: /* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */
983: int
1.20 djm 984: ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
1.25 djm 985: const struct sshkey **sign_ca_keys, size_t nsign_ca_keys)
1.1 djm 986: {
1.20 djm 987: struct sshbuf *copy = NULL, *sect = NULL;
988: struct ssh_krl *krl = NULL;
1.1 djm 989: char timestamp[64];
1.25 djm 990: int r = SSH_ERR_INTERNAL_ERROR, sig_seen;
1.20 djm 991: struct sshkey *key = NULL, **ca_used = NULL, **tmp_ca_used;
1.42 djm 992: u_char type;
1.15 djm 993: const u_char *blob;
1.42 djm 994: size_t i, j, sig_off, sects_off, blen, nca_used;
1.20 djm 995: u_int format_version;
1.1 djm 996:
1.12 markus 997: nca_used = 0;
1.1 djm 998: *krlp = NULL;
1.20 djm 999: if (sshbuf_len(buf) < sizeof(KRL_MAGIC) - 1 ||
1000: memcmp(sshbuf_ptr(buf), KRL_MAGIC, sizeof(KRL_MAGIC) - 1) != 0) {
1.1 djm 1001: debug3("%s: not a KRL", __func__);
1.20 djm 1002: return SSH_ERR_KRL_BAD_MAGIC;
1.1 djm 1003: }
1004:
1005: /* Take a copy of the KRL buffer so we can verify its signature later */
1.20 djm 1006: if ((copy = sshbuf_fromb(buf)) == NULL) {
1007: r = SSH_ERR_ALLOC_FAIL;
1008: goto out;
1009: }
1010: if ((r = sshbuf_consume(copy, sizeof(KRL_MAGIC) - 1)) != 0)
1011: goto out;
1.1 djm 1012:
1013: if ((krl = ssh_krl_init()) == NULL) {
1014: error("%s: alloc failed", __func__);
1015: goto out;
1016: }
1017:
1.20 djm 1018: if ((r = sshbuf_get_u32(copy, &format_version)) != 0)
1.1 djm 1019: goto out;
1020: if (format_version != KRL_FORMAT_VERSION) {
1.20 djm 1021: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1022: goto out;
1023: }
1.20 djm 1024: if ((r = sshbuf_get_u64(copy, &krl->krl_version)) != 0 ||
1025: (r = sshbuf_get_u64(copy, &krl->generated_date)) != 0 ||
1026: (r = sshbuf_get_u64(copy, &krl->flags)) != 0 ||
1027: (r = sshbuf_skip_string(copy)) != 0 ||
1028: (r = sshbuf_get_cstring(copy, &krl->comment, NULL)) != 0)
1.1 djm 1029: goto out;
1030:
1031: format_timestamp(krl->generated_date, timestamp, sizeof(timestamp));
1.11 djm 1032: debug("KRL version %llu generated at %s%s%s",
1033: (long long unsigned)krl->krl_version, timestamp,
1034: *krl->comment ? ": " : "", krl->comment);
1.1 djm 1035:
1036: /*
1037: * 1st pass: verify signatures, if any. This is done to avoid
1038: * detailed parsing of data whose provenance is unverified.
1039: */
1040: sig_seen = 0;
1.20 djm 1041: if (sshbuf_len(buf) < sshbuf_len(copy)) {
1042: /* Shouldn't happen */
1043: r = SSH_ERR_INTERNAL_ERROR;
1044: goto out;
1045: }
1046: sects_off = sshbuf_len(buf) - sshbuf_len(copy);
1047: while (sshbuf_len(copy) > 0) {
1048: if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
1049: (r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0)
1.1 djm 1050: goto out;
1.25 djm 1051: KRL_DBG(("%s: first pass, section 0x%02x", __func__, type));
1.1 djm 1052: if (type != KRL_SECTION_SIGNATURE) {
1053: if (sig_seen) {
1054: error("KRL contains non-signature section "
1055: "after signature");
1.25 djm 1056: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1057: goto out;
1058: }
1059: /* Not interested for now. */
1060: continue;
1061: }
1062: sig_seen = 1;
1063: /* First string component is the signing key */
1.20 djm 1064: if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
1065: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1066: goto out;
1067: }
1.20 djm 1068: if (sshbuf_len(buf) < sshbuf_len(copy)) {
1069: /* Shouldn't happen */
1070: r = SSH_ERR_INTERNAL_ERROR;
1071: goto out;
1072: }
1073: sig_off = sshbuf_len(buf) - sshbuf_len(copy);
1.1 djm 1074: /* Second string component is the signature itself */
1.20 djm 1075: if ((r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0) {
1076: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1077: goto out;
1078: }
1079: /* Check signature over entire KRL up to this point */
1.20 djm 1080: if ((r = sshkey_verify(key, blob, blen,
1.46 djm 1081: sshbuf_ptr(buf), sig_off, NULL, 0, NULL)) != 0)
1.1 djm 1082: goto out;
1083: /* Check if this key has already signed this KRL */
1084: for (i = 0; i < nca_used; i++) {
1.20 djm 1085: if (sshkey_equal(ca_used[i], key)) {
1.1 djm 1086: error("KRL signed more than once with "
1087: "the same key");
1.25 djm 1088: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1089: goto out;
1090: }
1091: }
1092: /* Record keys used to sign the KRL */
1.40 deraadt 1093: tmp_ca_used = recallocarray(ca_used, nca_used, nca_used + 1,
1.20 djm 1094: sizeof(*ca_used));
1095: if (tmp_ca_used == NULL) {
1096: r = SSH_ERR_ALLOC_FAIL;
1097: goto out;
1098: }
1099: ca_used = tmp_ca_used;
1.1 djm 1100: ca_used[nca_used++] = key;
1101: key = NULL;
1102: }
1103:
1.20 djm 1104: if (sshbuf_len(copy) != 0) {
1105: /* Shouldn't happen */
1106: r = SSH_ERR_INTERNAL_ERROR;
1107: goto out;
1108: }
1109:
1.1 djm 1110: /*
1111: * 2nd pass: parse and load the KRL, skipping the header to the point
1112: * where the section start.
1113: */
1.20 djm 1114: sshbuf_free(copy);
1115: if ((copy = sshbuf_fromb(buf)) == NULL) {
1116: r = SSH_ERR_ALLOC_FAIL;
1117: goto out;
1118: }
1119: if ((r = sshbuf_consume(copy, sects_off)) != 0)
1120: goto out;
1121: while (sshbuf_len(copy) > 0) {
1.36 mmcc 1122: sshbuf_free(sect);
1123: sect = NULL;
1.20 djm 1124: if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
1.25 djm 1125: (r = sshbuf_froms(copy, §)) != 0)
1.1 djm 1126: goto out;
1.25 djm 1127: KRL_DBG(("%s: second pass, section 0x%02x", __func__, type));
1.1 djm 1128:
1129: switch (type) {
1130: case KRL_SECTION_CERTIFICATES:
1.20 djm 1131: if ((r = parse_revoked_certs(sect, krl)) != 0)
1.1 djm 1132: goto out;
1133: break;
1134: case KRL_SECTION_EXPLICIT_KEY:
1.42 djm 1135: if ((r = blob_section(sect,
1136: &krl->revoked_keys, 0)) != 0)
1137: goto out;
1138: break;
1.1 djm 1139: case KRL_SECTION_FINGERPRINT_SHA1:
1.42 djm 1140: if ((r = blob_section(sect,
1141: &krl->revoked_sha1s, 20)) != 0)
1142: goto out;
1143: break;
1144: case KRL_SECTION_FINGERPRINT_SHA256:
1145: if ((r = blob_section(sect,
1146: &krl->revoked_sha256s, 32)) != 0)
1147: goto out;
1.1 djm 1148: break;
1149: case KRL_SECTION_SIGNATURE:
1150: /* Handled above, but still need to stay in synch */
1.39 dtucker 1151: sshbuf_free(sect);
1.20 djm 1152: sect = NULL;
1153: if ((r = sshbuf_skip_string(copy)) != 0)
1.1 djm 1154: goto out;
1155: break;
1156: default:
1157: error("Unsupported KRL section %u", type);
1.20 djm 1158: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1159: goto out;
1160: }
1.37 djm 1161: if (sect != NULL && sshbuf_len(sect) > 0) {
1.1 djm 1162: error("KRL section contains unparsed data");
1.20 djm 1163: r = SSH_ERR_INVALID_FORMAT;
1.1 djm 1164: goto out;
1165: }
1166: }
1167:
1168: /* Check that the key(s) used to sign the KRL weren't revoked */
1169: sig_seen = 0;
1170: for (i = 0; i < nca_used; i++) {
1171: if (ssh_krl_check_key(krl, ca_used[i]) == 0)
1172: sig_seen = 1;
1173: else {
1.20 djm 1174: sshkey_free(ca_used[i]);
1.1 djm 1175: ca_used[i] = NULL;
1176: }
1177: }
1178: if (nca_used && !sig_seen) {
1179: error("All keys used to sign KRL were revoked");
1.25 djm 1180: r = SSH_ERR_KEY_REVOKED;
1.1 djm 1181: goto out;
1182: }
1183:
1184: /* If we have CA keys, then verify that one was used to sign the KRL */
1185: if (sig_seen && nsign_ca_keys != 0) {
1186: sig_seen = 0;
1187: for (i = 0; !sig_seen && i < nsign_ca_keys; i++) {
1188: for (j = 0; j < nca_used; j++) {
1189: if (ca_used[j] == NULL)
1190: continue;
1.20 djm 1191: if (sshkey_equal(ca_used[j], sign_ca_keys[i])) {
1.1 djm 1192: sig_seen = 1;
1193: break;
1194: }
1195: }
1196: }
1197: if (!sig_seen) {
1.20 djm 1198: r = SSH_ERR_SIGNATURE_INVALID;
1.1 djm 1199: error("KRL not signed with any trusted key");
1200: goto out;
1201: }
1202: }
1203:
1204: *krlp = krl;
1.20 djm 1205: r = 0;
1.1 djm 1206: out:
1.20 djm 1207: if (r != 0)
1.1 djm 1208: ssh_krl_free(krl);
1.20 djm 1209: for (i = 0; i < nca_used; i++)
1210: sshkey_free(ca_used[i]);
1.1 djm 1211: free(ca_used);
1.20 djm 1212: sshkey_free(key);
1213: sshbuf_free(copy);
1214: sshbuf_free(sect);
1215: return r;
1.1 djm 1216: }
1217:
1.31 djm 1218: /* Checks certificate serial number and key ID revocation */
1219: static int
1220: is_cert_revoked(const struct sshkey *key, struct revoked_certs *rc)
1221: {
1222: struct revoked_serial rs, *ers;
1223: struct revoked_key_id rki, *erki;
1224:
1225: /* Check revocation by cert key ID */
1226: memset(&rki, 0, sizeof(rki));
1227: rki.key_id = key->cert->key_id;
1228: erki = RB_FIND(revoked_key_id_tree, &rc->revoked_key_ids, &rki);
1229: if (erki != NULL) {
1230: KRL_DBG(("%s: revoked by key ID", __func__));
1231: return SSH_ERR_KEY_REVOKED;
1232: }
1233:
1234: /*
1.33 djm 1235: * Zero serials numbers are ignored (it's the default when the
1236: * CA doesn't specify one).
1.31 djm 1237: */
1.33 djm 1238: if (key->cert->serial == 0)
1.31 djm 1239: return 0;
1240:
1241: memset(&rs, 0, sizeof(rs));
1242: rs.lo = rs.hi = key->cert->serial;
1243: ers = RB_FIND(revoked_serial_tree, &rc->revoked_serials, &rs);
1244: if (ers != NULL) {
1245: KRL_DBG(("%s: revoked serial %llu matched %llu:%llu", __func__,
1246: key->cert->serial, ers->lo, ers->hi));
1247: return SSH_ERR_KEY_REVOKED;
1248: }
1249: return 0;
1250: }
1251:
1.1 djm 1252: /* Checks whether a given key/cert is revoked. Does not check its CA */
1253: static int
1.20 djm 1254: is_key_revoked(struct ssh_krl *krl, const struct sshkey *key)
1.1 djm 1255: {
1256: struct revoked_blob rb, *erb;
1257: struct revoked_certs *rc;
1.20 djm 1258: int r;
1.1 djm 1259:
1260: /* Check explicitly revoked hashes first */
1.14 tedu 1261: memset(&rb, 0, sizeof(rb));
1.21 djm 1262: if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
1.20 djm 1263: &rb.blob, &rb.len)) != 0)
1264: return r;
1.1 djm 1265: erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha1s, &rb);
1266: free(rb.blob);
1267: if (erb != NULL) {
1.25 djm 1268: KRL_DBG(("%s: revoked by key SHA1", __func__));
1.42 djm 1269: return SSH_ERR_KEY_REVOKED;
1270: }
1271: memset(&rb, 0, sizeof(rb));
1272: if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA256,
1273: &rb.blob, &rb.len)) != 0)
1274: return r;
1275: erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha256s, &rb);
1276: free(rb.blob);
1277: if (erb != NULL) {
1278: KRL_DBG(("%s: revoked by key SHA256", __func__));
1.20 djm 1279: return SSH_ERR_KEY_REVOKED;
1.1 djm 1280: }
1281:
1282: /* Next, explicit keys */
1.14 tedu 1283: memset(&rb, 0, sizeof(rb));
1.20 djm 1284: if ((r = plain_key_blob(key, &rb.blob, &rb.len)) != 0)
1285: return r;
1.1 djm 1286: erb = RB_FIND(revoked_blob_tree, &krl->revoked_keys, &rb);
1287: free(rb.blob);
1288: if (erb != NULL) {
1.25 djm 1289: KRL_DBG(("%s: revoked by explicit key", __func__));
1.20 djm 1290: return SSH_ERR_KEY_REVOKED;
1.1 djm 1291: }
1292:
1.20 djm 1293: if (!sshkey_is_cert(key))
1.1 djm 1294: return 0;
1295:
1.31 djm 1296: /* Check cert revocation for the specified CA */
1.20 djm 1297: if ((r = revoked_certs_for_ca_key(krl, key->cert->signature_key,
1298: &rc, 0)) != 0)
1299: return r;
1.31 djm 1300: if (rc != NULL) {
1301: if ((r = is_cert_revoked(key, rc)) != 0)
1302: return r;
1303: }
1304: /* Check cert revocation for the wildcard CA */
1305: if ((r = revoked_certs_for_ca_key(krl, NULL, &rc, 0)) != 0)
1306: return r;
1307: if (rc != NULL) {
1308: if ((r = is_cert_revoked(key, rc)) != 0)
1309: return r;
1.1 djm 1310: }
1311:
1312: KRL_DBG(("%s: %llu no match", __func__, key->cert->serial));
1313: return 0;
1314: }
1315:
1316: int
1.20 djm 1317: ssh_krl_check_key(struct ssh_krl *krl, const struct sshkey *key)
1.1 djm 1318: {
1319: int r;
1320:
1.25 djm 1321: KRL_DBG(("%s: checking key", __func__));
1.1 djm 1322: if ((r = is_key_revoked(krl, key)) != 0)
1323: return r;
1.20 djm 1324: if (sshkey_is_cert(key)) {
1.1 djm 1325: debug2("%s: checking CA key", __func__);
1326: if ((r = is_key_revoked(krl, key->cert->signature_key)) != 0)
1327: return r;
1328: }
1.25 djm 1329: KRL_DBG(("%s: key okay", __func__));
1.1 djm 1330: return 0;
1331: }
1332:
1333: int
1.20 djm 1334: ssh_krl_file_contains_key(const char *path, const struct sshkey *key)
1.1 djm 1335: {
1.20 djm 1336: struct sshbuf *krlbuf = NULL;
1337: struct ssh_krl *krl = NULL;
1.47 djm 1338: int oerrno = 0, r;
1.1 djm 1339:
1340: if (path == NULL)
1341: return 0;
1.47 djm 1342: if ((r = sshbuf_load_file(path, &krlbuf)) != 0) {
1.20 djm 1343: oerrno = errno;
1344: goto out;
1.1 djm 1345: }
1.20 djm 1346: if ((r = ssh_krl_from_blob(krlbuf, &krl, NULL, 0)) != 0)
1347: goto out;
1348: debug2("%s: checking KRL %s", __func__, path);
1349: r = ssh_krl_check_key(krl, key);
1350: out:
1351: sshbuf_free(krlbuf);
1.1 djm 1352: ssh_krl_free(krl);
1.20 djm 1353: if (r != 0)
1354: errno = oerrno;
1355: return r;
1.48 djm 1356: }
1357:
1358: int
1359: krl_dump(struct ssh_krl *krl, FILE *f)
1360: {
1361: struct sshkey *key = NULL;
1362: struct revoked_blob *rb;
1363: struct revoked_certs *rc;
1364: struct revoked_serial *rs;
1365: struct revoked_key_id *rki;
1366: int r, ret = 0;
1367: char *fp, timestamp[64];
1368:
1369: /* Try to print in a KRL spec-compatible format */
1370: format_timestamp(krl->generated_date, timestamp, sizeof(timestamp));
1.49 ! djm 1371: fprintf(f, "# KRL version %llu\n", krl->krl_version);
1.48 djm 1372: fprintf(f, "# Generated at %s\n", timestamp);
1373: if (krl->comment != NULL && *krl->comment != '\0') {
1374: r = INT_MAX;
1375: asmprintf(&fp, INT_MAX, &r, "%s", krl->comment);
1376: fprintf(f, "# Comment: %s\n", fp);
1377: free(fp);
1378: }
1379: fputc('\n', f);
1380:
1381: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) {
1382: if ((r = sshkey_from_blob(rb->blob, rb->len, &key)) != 0) {
1383: ret = SSH_ERR_INVALID_FORMAT;
1384: error("Parse key in KRL: %s", ssh_err(r));
1385: continue;
1386: }
1387: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
1388: SSH_FP_DEFAULT)) == NULL) {
1389: ret = SSH_ERR_INVALID_FORMAT;
1390: error("sshkey_fingerprint failed");
1391: continue;
1392: }
1393: fprintf(f, "hash: SHA256:%s # %s\n", fp, sshkey_ssh_name(key));
1394: free(fp);
1395: free(key);
1396: }
1397: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) {
1398: fp = tohex(rb->blob, rb->len);
1399: fprintf(f, "hash: SHA256:%s\n", fp);
1400: free(fp);
1401: }
1402: RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) {
1403: /*
1404: * There is not KRL spec keyword for raw SHA1 hashes, so
1405: * print them as comments.
1406: */
1407: fp = tohex(rb->blob, rb->len);
1408: fprintf(f, "# hash SHA1:%s\n", fp);
1409: free(fp);
1410: }
1411:
1412: TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
1413: fputc('\n', f);
1414: if (rc->ca_key == NULL)
1415: fprintf(f, "# Wildcard CA\n");
1416: else {
1417: if ((fp = sshkey_fingerprint(rc->ca_key,
1418: SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL) {
1419: ret = SSH_ERR_INVALID_FORMAT;
1420: error("sshkey_fingerprint failed");
1421: continue;
1422: }
1423: fprintf(f, "# CA key %s %s\n",
1424: sshkey_ssh_name(rc->ca_key), fp);
1425: free(fp);
1426: }
1427: RB_FOREACH(rs, revoked_serial_tree, &rc->revoked_serials) {
1428: if (rs->lo == rs->hi)
1.49 ! djm 1429: fprintf(f, "serial: %llu\n", rs->lo);
1.48 djm 1430: else {
1.49 ! djm 1431: fprintf(f, "serial: %llu-%llu\n",
1.48 djm 1432: rs->lo, rs->hi);
1433: }
1434: }
1435: RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) {
1436: /*
1437: * We don't want key IDs with embedded newlines to
1438: * mess up the display.
1439: */
1440: r = INT_MAX;
1441: asmprintf(&fp, INT_MAX, &r, "%s", rki->key_id);
1442: fprintf(f, "id: %s\n", fp);
1443: free(fp);
1444: }
1445: }
1446: return ret;
1.1 djm 1447: }
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