2 * Copyright (c) 2012 Damien Miller <djm@mindrot.org>
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.
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.
17 /* $OpenBSD: krl.c,v 1.37 2015/12/31 00:33:52 djm Exp $ */
21 #include <sys/param.h> /* MIN */
22 #include <sys/types.h>
23 #include <openbsd-compat/sys-tree.h>
24 #include <openbsd-compat/sys-queue.h>
44 /* #define DEBUG_KRL */
46 # define KRL_DBG(x) debug3 x
52 * Trees of revoked serial numbers, key IDs and keys. This allows
53 * quick searching, querying and producing lists in canonical order.
56 /* Tree of serial numbers. XXX make smarter: really need a real sparse bitmap */
57 struct revoked_serial {
59 RB_ENTRY(revoked_serial) tree_entry;
61 static int serial_cmp(struct revoked_serial *a, struct revoked_serial *b);
62 RB_HEAD(revoked_serial_tree, revoked_serial);
63 RB_GENERATE_STATIC(revoked_serial_tree, revoked_serial, tree_entry, serial_cmp);
66 struct revoked_key_id {
68 RB_ENTRY(revoked_key_id) tree_entry;
70 static int key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b);
71 RB_HEAD(revoked_key_id_tree, revoked_key_id);
72 RB_GENERATE_STATIC(revoked_key_id_tree, revoked_key_id, tree_entry, key_id_cmp);
74 /* Tree of blobs (used for keys and fingerprints) */
78 RB_ENTRY(revoked_blob) tree_entry;
80 static int blob_cmp(struct revoked_blob *a, struct revoked_blob *b);
81 RB_HEAD(revoked_blob_tree, revoked_blob);
82 RB_GENERATE_STATIC(revoked_blob_tree, revoked_blob, tree_entry, blob_cmp);
84 /* Tracks revoked certs for a single CA */
85 struct revoked_certs {
86 struct sshkey *ca_key;
87 struct revoked_serial_tree revoked_serials;
88 struct revoked_key_id_tree revoked_key_ids;
89 TAILQ_ENTRY(revoked_certs) entry;
91 TAILQ_HEAD(revoked_certs_list, revoked_certs);
94 u_int64_t krl_version;
95 u_int64_t generated_date;
98 struct revoked_blob_tree revoked_keys;
99 struct revoked_blob_tree revoked_sha1s;
100 struct revoked_certs_list revoked_certs;
103 /* Return equal if a and b overlap */
105 serial_cmp(struct revoked_serial *a, struct revoked_serial *b)
107 if (a->hi >= b->lo && a->lo <= b->hi)
109 return a->lo < b->lo ? -1 : 1;
113 key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b)
115 return strcmp(a->key_id, b->key_id);
119 blob_cmp(struct revoked_blob *a, struct revoked_blob *b)
123 if (a->len != b->len) {
124 if ((r = memcmp(a->blob, b->blob, MIN(a->len, b->len))) != 0)
126 return a->len > b->len ? 1 : -1;
128 return memcmp(a->blob, b->blob, a->len);
136 if ((krl = calloc(1, sizeof(*krl))) == NULL)
138 RB_INIT(&krl->revoked_keys);
139 RB_INIT(&krl->revoked_sha1s);
140 TAILQ_INIT(&krl->revoked_certs);
145 revoked_certs_free(struct revoked_certs *rc)
147 struct revoked_serial *rs, *trs;
148 struct revoked_key_id *rki, *trki;
150 RB_FOREACH_SAFE(rs, revoked_serial_tree, &rc->revoked_serials, trs) {
151 RB_REMOVE(revoked_serial_tree, &rc->revoked_serials, rs);
154 RB_FOREACH_SAFE(rki, revoked_key_id_tree, &rc->revoked_key_ids, trki) {
155 RB_REMOVE(revoked_key_id_tree, &rc->revoked_key_ids, rki);
159 sshkey_free(rc->ca_key);
163 ssh_krl_free(struct ssh_krl *krl)
165 struct revoked_blob *rb, *trb;
166 struct revoked_certs *rc, *trc;
172 RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_keys, trb) {
173 RB_REMOVE(revoked_blob_tree, &krl->revoked_keys, rb);
177 RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha1s, trb) {
178 RB_REMOVE(revoked_blob_tree, &krl->revoked_sha1s, rb);
182 TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) {
183 TAILQ_REMOVE(&krl->revoked_certs, rc, entry);
184 revoked_certs_free(rc);
189 ssh_krl_set_version(struct ssh_krl *krl, u_int64_t version)
191 krl->krl_version = version;
195 ssh_krl_set_comment(struct ssh_krl *krl, const char *comment)
198 if ((krl->comment = strdup(comment)) == NULL)
199 return SSH_ERR_ALLOC_FAIL;
204 * Find the revoked_certs struct for a CA key. If allow_create is set then
205 * create a new one in the tree if one did not exist already.
208 revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
209 struct revoked_certs **rcp, int allow_create)
211 struct revoked_certs *rc;
215 TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
216 if ((ca_key == NULL && rc->ca_key == NULL) ||
217 sshkey_equal(rc->ca_key, ca_key)) {
224 /* If this CA doesn't exist in the list then add it now */
225 if ((rc = calloc(1, sizeof(*rc))) == NULL)
226 return SSH_ERR_ALLOC_FAIL;
229 else if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
233 RB_INIT(&rc->revoked_serials);
234 RB_INIT(&rc->revoked_key_ids);
235 TAILQ_INSERT_TAIL(&krl->revoked_certs, rc, entry);
236 KRL_DBG(("%s: new CA %s", __func__,
237 ca_key == NULL ? "*" : sshkey_type(ca_key)));
243 insert_serial_range(struct revoked_serial_tree *rt, u_int64_t lo, u_int64_t hi)
245 struct revoked_serial rs, *ers, *crs, *irs;
247 KRL_DBG(("%s: insert %llu:%llu", __func__, lo, hi));
248 memset(&rs, 0, sizeof(rs));
251 ers = RB_NFIND(revoked_serial_tree, rt, &rs);
252 if (ers == NULL || serial_cmp(ers, &rs) != 0) {
253 /* No entry matches. Just insert */
254 if ((irs = malloc(sizeof(rs))) == NULL)
255 return SSH_ERR_ALLOC_FAIL;
256 memcpy(irs, &rs, sizeof(*irs));
257 ers = RB_INSERT(revoked_serial_tree, rt, irs);
259 KRL_DBG(("%s: bad: ers != NULL", __func__));
260 /* Shouldn't happen */
262 return SSH_ERR_INTERNAL_ERROR;
266 KRL_DBG(("%s: overlap found %llu:%llu", __func__,
269 * The inserted entry overlaps an existing one. Grow the
279 * The inserted or revised range might overlap or abut adjacent ones;
280 * coalesce as necessary.
283 /* Check predecessors */
284 while ((crs = RB_PREV(revoked_serial_tree, rt, ers)) != NULL) {
285 KRL_DBG(("%s: pred %llu:%llu", __func__, crs->lo, crs->hi));
286 if (ers->lo != 0 && crs->hi < ers->lo - 1)
288 /* This entry overlaps. */
289 if (crs->lo < ers->lo) {
291 KRL_DBG(("%s: pred extend %llu:%llu", __func__,
294 RB_REMOVE(revoked_serial_tree, rt, crs);
297 /* Check successors */
298 while ((crs = RB_NEXT(revoked_serial_tree, rt, ers)) != NULL) {
299 KRL_DBG(("%s: succ %llu:%llu", __func__, crs->lo, crs->hi));
300 if (ers->hi != (u_int64_t)-1 && crs->lo > ers->hi + 1)
302 /* This entry overlaps. */
303 if (crs->hi > ers->hi) {
305 KRL_DBG(("%s: succ extend %llu:%llu", __func__,
308 RB_REMOVE(revoked_serial_tree, rt, crs);
311 KRL_DBG(("%s: done, final %llu:%llu", __func__, ers->lo, ers->hi));
316 ssh_krl_revoke_cert_by_serial(struct ssh_krl *krl, const struct sshkey *ca_key,
319 return ssh_krl_revoke_cert_by_serial_range(krl, ca_key, serial, serial);
323 ssh_krl_revoke_cert_by_serial_range(struct ssh_krl *krl,
324 const struct sshkey *ca_key, u_int64_t lo, u_int64_t hi)
326 struct revoked_certs *rc;
329 if (lo > hi || lo == 0)
330 return SSH_ERR_INVALID_ARGUMENT;
331 if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
333 return insert_serial_range(&rc->revoked_serials, lo, hi);
337 ssh_krl_revoke_cert_by_key_id(struct ssh_krl *krl, const struct sshkey *ca_key,
340 struct revoked_key_id *rki, *erki;
341 struct revoked_certs *rc;
344 if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
347 KRL_DBG(("%s: revoke %s", __func__, key_id));
348 if ((rki = calloc(1, sizeof(*rki))) == NULL ||
349 (rki->key_id = strdup(key_id)) == NULL) {
351 return SSH_ERR_ALLOC_FAIL;
353 erki = RB_INSERT(revoked_key_id_tree, &rc->revoked_key_ids, rki);
361 /* Convert "key" to a public key blob without any certificate information */
363 plain_key_blob(const struct sshkey *key, u_char **blob, size_t *blen)
365 struct sshkey *kcopy;
368 if ((r = sshkey_from_private(key, &kcopy)) != 0)
370 if (sshkey_is_cert(kcopy)) {
371 if ((r = sshkey_drop_cert(kcopy)) != 0) {
376 r = sshkey_to_blob(kcopy, blob, blen);
381 /* Revoke a key blob. Ownership of blob is transferred to the tree */
383 revoke_blob(struct revoked_blob_tree *rbt, u_char *blob, size_t len)
385 struct revoked_blob *rb, *erb;
387 if ((rb = calloc(1, sizeof(*rb))) == NULL)
388 return SSH_ERR_ALLOC_FAIL;
391 erb = RB_INSERT(revoked_blob_tree, rbt, rb);
400 ssh_krl_revoke_key_explicit(struct ssh_krl *krl, const struct sshkey *key)
406 debug3("%s: revoke type %s", __func__, sshkey_type(key));
407 if ((r = plain_key_blob(key, &blob, &len)) != 0)
409 return revoke_blob(&krl->revoked_keys, blob, len);
413 ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const struct sshkey *key)
419 debug3("%s: revoke type %s by sha1", __func__, sshkey_type(key));
420 if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
423 return revoke_blob(&krl->revoked_sha1s, blob, len);
427 ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key)
429 if (!sshkey_is_cert(key))
430 return ssh_krl_revoke_key_sha1(krl, key);
432 if (key->cert->serial == 0) {
433 return ssh_krl_revoke_cert_by_key_id(krl,
434 key->cert->signature_key,
437 return ssh_krl_revoke_cert_by_serial(krl,
438 key->cert->signature_key,
444 * Select the most compact section type to emit next in a KRL based on
445 * the current section type, the run length of contiguous revoked serial
446 * numbers and the gaps from the last and to the next revoked serial.
447 * Applies a mostly-accurate bit cost model to select the section type
448 * that will minimise the size of the resultant KRL.
451 choose_next_state(int current_state, u_int64_t contig, int final,
452 u_int64_t last_gap, u_int64_t next_gap, int *force_new_section)
455 u_int64_t cost, cost_list, cost_range, cost_bitmap, cost_bitmap_restart;
458 * Avoid unsigned overflows.
459 * The limits are high enough to avoid confusing the calculations.
461 contig = MIN(contig, 1ULL<<31);
462 last_gap = MIN(last_gap, 1ULL<<31);
463 next_gap = MIN(next_gap, 1ULL<<31);
466 * Calculate the cost to switch from the current state to candidates.
467 * NB. range sections only ever contain a single range, so their
468 * switching cost is independent of the current_state.
470 cost_list = cost_bitmap = cost_bitmap_restart = 0;
472 switch (current_state) {
473 case KRL_SECTION_CERT_SERIAL_LIST:
474 cost_bitmap_restart = cost_bitmap = 8 + 64;
476 case KRL_SECTION_CERT_SERIAL_BITMAP:
478 cost_bitmap_restart = 8 + 64;
480 case KRL_SECTION_CERT_SERIAL_RANGE:
482 cost_bitmap_restart = cost_bitmap = 8 + 64;
486 /* Estimate base cost in bits of each section type */
487 cost_list += 64 * contig + (final ? 0 : 8+64);
488 cost_range += (2 * 64) + (final ? 0 : 8+64);
489 cost_bitmap += last_gap + contig + (final ? 0 : MIN(next_gap, 8+64));
490 cost_bitmap_restart += contig + (final ? 0 : MIN(next_gap, 8+64));
492 /* Convert to byte costs for actual comparison */
493 cost_list = (cost_list + 7) / 8;
494 cost_bitmap = (cost_bitmap + 7) / 8;
495 cost_bitmap_restart = (cost_bitmap_restart + 7) / 8;
496 cost_range = (cost_range + 7) / 8;
498 /* Now pick the best choice */
499 *force_new_section = 0;
500 new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
502 if (cost_range < cost) {
503 new_state = KRL_SECTION_CERT_SERIAL_RANGE;
506 if (cost_list < cost) {
507 new_state = KRL_SECTION_CERT_SERIAL_LIST;
510 if (cost_bitmap_restart < cost) {
511 new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
512 *force_new_section = 1;
513 cost = cost_bitmap_restart;
515 KRL_DBG(("%s: contig %llu last_gap %llu next_gap %llu final %d, costs:"
516 "list %llu range %llu bitmap %llu new bitmap %llu, "
517 "selected 0x%02x%s", __func__, (long long unsigned)contig,
518 (long long unsigned)last_gap, (long long unsigned)next_gap, final,
519 (long long unsigned)cost_list, (long long unsigned)cost_range,
520 (long long unsigned)cost_bitmap,
521 (long long unsigned)cost_bitmap_restart, new_state,
522 *force_new_section ? " restart" : ""));
527 put_bitmap(struct sshbuf *buf, struct bitmap *bitmap)
533 len = bitmap_nbytes(bitmap);
534 if ((blob = malloc(len)) == NULL)
535 return SSH_ERR_ALLOC_FAIL;
536 if (bitmap_to_string(bitmap, blob, len) != 0) {
538 return SSH_ERR_INTERNAL_ERROR;
540 r = sshbuf_put_bignum2_bytes(buf, blob, len);
545 /* Generate a KRL_SECTION_CERTIFICATES KRL section */
547 revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
549 int final, force_new_sect, r = SSH_ERR_INTERNAL_ERROR;
550 u_int64_t i, contig, gap, last = 0, bitmap_start = 0;
551 struct revoked_serial *rs, *nrs;
552 struct revoked_key_id *rki;
553 int next_state, state = 0;
555 struct bitmap *bitmap = NULL;
557 if ((sect = sshbuf_new()) == NULL)
558 return SSH_ERR_ALLOC_FAIL;
560 /* Store the header: optional CA scope key, reserved */
561 if (rc->ca_key == NULL) {
562 if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
565 if ((r = sshkey_puts(rc->ca_key, buf)) != 0)
568 if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
571 /* Store the revoked serials. */
572 for (rs = RB_MIN(revoked_serial_tree, &rc->revoked_serials);
574 rs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs)) {
575 KRL_DBG(("%s: serial %llu:%llu state 0x%02x", __func__,
576 (long long unsigned)rs->lo, (long long unsigned)rs->hi,
579 /* Check contiguous length and gap to next section (if any) */
580 nrs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs);
582 gap = nrs == NULL ? 0 : nrs->lo - rs->hi;
583 contig = 1 + (rs->hi - rs->lo);
585 /* Choose next state based on these */
586 next_state = choose_next_state(state, contig, final,
587 state == 0 ? 0 : rs->lo - last, gap, &force_new_sect);
590 * If the current section is a range section or has a different
591 * type to the next section, then finish it off now.
593 if (state != 0 && (force_new_sect || next_state != state ||
594 state == KRL_SECTION_CERT_SERIAL_RANGE)) {
595 KRL_DBG(("%s: finish state 0x%02x", __func__, state));
597 case KRL_SECTION_CERT_SERIAL_LIST:
598 case KRL_SECTION_CERT_SERIAL_RANGE:
600 case KRL_SECTION_CERT_SERIAL_BITMAP:
601 if ((r = put_bitmap(sect, bitmap)) != 0)
607 if ((r = sshbuf_put_u8(buf, state)) != 0 ||
608 (r = sshbuf_put_stringb(buf, sect)) != 0)
613 /* If we are starting a new section then prepare it now */
614 if (next_state != state || force_new_sect) {
615 KRL_DBG(("%s: start state 0x%02x", __func__,
620 case KRL_SECTION_CERT_SERIAL_LIST:
621 case KRL_SECTION_CERT_SERIAL_RANGE:
623 case KRL_SECTION_CERT_SERIAL_BITMAP:
624 if ((bitmap = bitmap_new()) == NULL) {
625 r = SSH_ERR_ALLOC_FAIL;
628 bitmap_start = rs->lo;
629 if ((r = sshbuf_put_u64(sect,
636 /* Perform section-specific processing */
638 case KRL_SECTION_CERT_SERIAL_LIST:
639 for (i = 0; i < contig; i++) {
640 if ((r = sshbuf_put_u64(sect, rs->lo + i)) != 0)
644 case KRL_SECTION_CERT_SERIAL_RANGE:
645 if ((r = sshbuf_put_u64(sect, rs->lo)) != 0 ||
646 (r = sshbuf_put_u64(sect, rs->hi)) != 0)
649 case KRL_SECTION_CERT_SERIAL_BITMAP:
650 if (rs->lo - bitmap_start > INT_MAX) {
651 error("%s: insane bitmap gap", __func__);
654 for (i = 0; i < contig; i++) {
655 if (bitmap_set_bit(bitmap,
656 rs->lo + i - bitmap_start) != 0) {
657 r = SSH_ERR_ALLOC_FAIL;
665 /* Flush the remaining section, if any */
667 KRL_DBG(("%s: serial final flush for state 0x%02x",
670 case KRL_SECTION_CERT_SERIAL_LIST:
671 case KRL_SECTION_CERT_SERIAL_RANGE:
673 case KRL_SECTION_CERT_SERIAL_BITMAP:
674 if ((r = put_bitmap(sect, bitmap)) != 0)
680 if ((r = sshbuf_put_u8(buf, state)) != 0 ||
681 (r = sshbuf_put_stringb(buf, sect)) != 0)
684 KRL_DBG(("%s: serial done ", __func__));
686 /* Now output a section for any revocations by key ID */
688 RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) {
689 KRL_DBG(("%s: key ID %s", __func__, rki->key_id));
690 if ((r = sshbuf_put_cstring(sect, rki->key_id)) != 0)
693 if (sshbuf_len(sect) != 0) {
694 if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERT_KEY_ID)) != 0 ||
695 (r = sshbuf_put_stringb(buf, sect)) != 0)
706 ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf,
707 const struct sshkey **sign_keys, u_int nsign_keys)
709 int r = SSH_ERR_INTERNAL_ERROR;
710 struct revoked_certs *rc;
711 struct revoked_blob *rb;
713 u_char *sblob = NULL;
716 if (krl->generated_date == 0)
717 krl->generated_date = time(NULL);
719 if ((sect = sshbuf_new()) == NULL)
720 return SSH_ERR_ALLOC_FAIL;
722 /* Store the header */
723 if ((r = sshbuf_put(buf, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0 ||
724 (r = sshbuf_put_u32(buf, KRL_FORMAT_VERSION)) != 0 ||
725 (r = sshbuf_put_u64(buf, krl->krl_version)) != 0 ||
726 (r = sshbuf_put_u64(buf, krl->generated_date)) != 0 ||
727 (r = sshbuf_put_u64(buf, krl->flags)) != 0 ||
728 (r = sshbuf_put_string(buf, NULL, 0)) != 0 ||
729 (r = sshbuf_put_cstring(buf, krl->comment)) != 0)
732 /* Store sections for revoked certificates */
733 TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
735 if ((r = revoked_certs_generate(rc, sect)) != 0)
737 if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERTIFICATES)) != 0 ||
738 (r = sshbuf_put_stringb(buf, sect)) != 0)
742 /* Finally, output sections for revocations by public key/hash */
744 RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) {
745 KRL_DBG(("%s: key len %zu ", __func__, rb->len));
746 if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
749 if (sshbuf_len(sect) != 0) {
750 if ((r = sshbuf_put_u8(buf, KRL_SECTION_EXPLICIT_KEY)) != 0 ||
751 (r = sshbuf_put_stringb(buf, sect)) != 0)
755 RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) {
756 KRL_DBG(("%s: hash len %zu ", __func__, rb->len));
757 if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
760 if (sshbuf_len(sect) != 0) {
761 if ((r = sshbuf_put_u8(buf,
762 KRL_SECTION_FINGERPRINT_SHA1)) != 0 ||
763 (r = sshbuf_put_stringb(buf, sect)) != 0)
767 for (i = 0; i < nsign_keys; i++) {
768 KRL_DBG(("%s: signature key %s", __func__,
769 sshkey_ssh_name(sign_keys[i])));
770 if ((r = sshbuf_put_u8(buf, KRL_SECTION_SIGNATURE)) != 0 ||
771 (r = sshkey_puts(sign_keys[i], buf)) != 0)
774 if ((r = sshkey_sign(sign_keys[i], &sblob, &slen,
775 sshbuf_ptr(buf), sshbuf_len(buf), NULL, 0)) != 0)
777 KRL_DBG(("%s: signature sig len %zu", __func__, slen));
778 if ((r = sshbuf_put_string(buf, sblob, slen)) != 0)
790 format_timestamp(u_int64_t timestamp, char *ts, size_t nts)
798 strlcpy(ts, "<INVALID>", nts);
801 strftime(ts, nts, "%Y%m%dT%H%M%S", tm);
806 parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
808 int r = SSH_ERR_INTERNAL_ERROR;
812 struct sshbuf *subsect = NULL;
813 u_int64_t serial, serial_lo, serial_hi;
814 struct bitmap *bitmap = NULL;
816 struct sshkey *ca_key = NULL;
818 if ((subsect = sshbuf_new()) == NULL)
819 return SSH_ERR_ALLOC_FAIL;
821 /* Header: key, reserved */
822 if ((r = sshbuf_get_string_direct(buf, &blob, &blen)) != 0 ||
823 (r = sshbuf_skip_string(buf)) != 0)
825 if (blen != 0 && (r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
828 while (sshbuf_len(buf) > 0) {
829 sshbuf_free(subsect);
831 if ((r = sshbuf_get_u8(buf, &type)) != 0 ||
832 (r = sshbuf_froms(buf, &subsect)) != 0)
834 KRL_DBG(("%s: subsection type 0x%02x", __func__, type));
835 /* sshbuf_dump(subsect, stderr); */
838 case KRL_SECTION_CERT_SERIAL_LIST:
839 while (sshbuf_len(subsect) > 0) {
840 if ((r = sshbuf_get_u64(subsect, &serial)) != 0)
842 if ((r = ssh_krl_revoke_cert_by_serial(krl,
843 ca_key, serial)) != 0)
847 case KRL_SECTION_CERT_SERIAL_RANGE:
848 if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
849 (r = sshbuf_get_u64(subsect, &serial_hi)) != 0)
851 if ((r = ssh_krl_revoke_cert_by_serial_range(krl,
852 ca_key, serial_lo, serial_hi)) != 0)
855 case KRL_SECTION_CERT_SERIAL_BITMAP:
856 if ((bitmap = bitmap_new()) == NULL) {
857 r = SSH_ERR_ALLOC_FAIL;
860 if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
861 (r = sshbuf_get_bignum2_bytes_direct(subsect,
864 if (bitmap_from_string(bitmap, blob, blen) != 0) {
865 r = SSH_ERR_INVALID_FORMAT;
868 nbits = bitmap_nbits(bitmap);
869 for (serial = 0; serial < (u_int64_t)nbits; serial++) {
870 if (serial > 0 && serial_lo + serial == 0) {
871 error("%s: bitmap wraps u64", __func__);
872 r = SSH_ERR_INVALID_FORMAT;
875 if (!bitmap_test_bit(bitmap, serial))
877 if ((r = ssh_krl_revoke_cert_by_serial(krl,
878 ca_key, serial_lo + serial)) != 0)
884 case KRL_SECTION_CERT_KEY_ID:
885 while (sshbuf_len(subsect) > 0) {
886 if ((r = sshbuf_get_cstring(subsect,
887 &key_id, NULL)) != 0)
889 if ((r = ssh_krl_revoke_cert_by_key_id(krl,
890 ca_key, key_id)) != 0)
897 error("Unsupported KRL certificate section %u", type);
898 r = SSH_ERR_INVALID_FORMAT;
901 if (sshbuf_len(subsect) > 0) {
902 error("KRL certificate section contains unparsed data");
903 r = SSH_ERR_INVALID_FORMAT;
914 sshbuf_free(subsect);
919 /* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */
921 ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
922 const struct sshkey **sign_ca_keys, size_t nsign_ca_keys)
924 struct sshbuf *copy = NULL, *sect = NULL;
925 struct ssh_krl *krl = NULL;
927 int r = SSH_ERR_INTERNAL_ERROR, sig_seen;
928 struct sshkey *key = NULL, **ca_used = NULL, **tmp_ca_used;
929 u_char type, *rdata = NULL;
931 size_t i, j, sig_off, sects_off, rlen, blen, nca_used;
932 u_int format_version;
936 if (sshbuf_len(buf) < sizeof(KRL_MAGIC) - 1 ||
937 memcmp(sshbuf_ptr(buf), KRL_MAGIC, sizeof(KRL_MAGIC) - 1) != 0) {
938 debug3("%s: not a KRL", __func__);
939 return SSH_ERR_KRL_BAD_MAGIC;
942 /* Take a copy of the KRL buffer so we can verify its signature later */
943 if ((copy = sshbuf_fromb(buf)) == NULL) {
944 r = SSH_ERR_ALLOC_FAIL;
947 if ((r = sshbuf_consume(copy, sizeof(KRL_MAGIC) - 1)) != 0)
950 if ((krl = ssh_krl_init()) == NULL) {
951 error("%s: alloc failed", __func__);
955 if ((r = sshbuf_get_u32(copy, &format_version)) != 0)
957 if (format_version != KRL_FORMAT_VERSION) {
958 r = SSH_ERR_INVALID_FORMAT;
961 if ((r = sshbuf_get_u64(copy, &krl->krl_version)) != 0 ||
962 (r = sshbuf_get_u64(copy, &krl->generated_date)) != 0 ||
963 (r = sshbuf_get_u64(copy, &krl->flags)) != 0 ||
964 (r = sshbuf_skip_string(copy)) != 0 ||
965 (r = sshbuf_get_cstring(copy, &krl->comment, NULL)) != 0)
968 format_timestamp(krl->generated_date, timestamp, sizeof(timestamp));
969 debug("KRL version %llu generated at %s%s%s",
970 (long long unsigned)krl->krl_version, timestamp,
971 *krl->comment ? ": " : "", krl->comment);
974 * 1st pass: verify signatures, if any. This is done to avoid
975 * detailed parsing of data whose provenance is unverified.
978 if (sshbuf_len(buf) < sshbuf_len(copy)) {
979 /* Shouldn't happen */
980 r = SSH_ERR_INTERNAL_ERROR;
983 sects_off = sshbuf_len(buf) - sshbuf_len(copy);
984 while (sshbuf_len(copy) > 0) {
985 if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
986 (r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0)
988 KRL_DBG(("%s: first pass, section 0x%02x", __func__, type));
989 if (type != KRL_SECTION_SIGNATURE) {
991 error("KRL contains non-signature section "
993 r = SSH_ERR_INVALID_FORMAT;
996 /* Not interested for now. */
1000 /* First string component is the signing key */
1001 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
1002 r = SSH_ERR_INVALID_FORMAT;
1005 if (sshbuf_len(buf) < sshbuf_len(copy)) {
1006 /* Shouldn't happen */
1007 r = SSH_ERR_INTERNAL_ERROR;
1010 sig_off = sshbuf_len(buf) - sshbuf_len(copy);
1011 /* Second string component is the signature itself */
1012 if ((r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0) {
1013 r = SSH_ERR_INVALID_FORMAT;
1016 /* Check signature over entire KRL up to this point */
1017 if ((r = sshkey_verify(key, blob, blen,
1018 sshbuf_ptr(buf), sig_off, 0)) != 0)
1020 /* Check if this key has already signed this KRL */
1021 for (i = 0; i < nca_used; i++) {
1022 if (sshkey_equal(ca_used[i], key)) {
1023 error("KRL signed more than once with "
1025 r = SSH_ERR_INVALID_FORMAT;
1029 /* Record keys used to sign the KRL */
1030 tmp_ca_used = reallocarray(ca_used, nca_used + 1,
1032 if (tmp_ca_used == NULL) {
1033 r = SSH_ERR_ALLOC_FAIL;
1036 ca_used = tmp_ca_used;
1037 ca_used[nca_used++] = key;
1041 if (sshbuf_len(copy) != 0) {
1042 /* Shouldn't happen */
1043 r = SSH_ERR_INTERNAL_ERROR;
1048 * 2nd pass: parse and load the KRL, skipping the header to the point
1049 * where the section start.
1052 if ((copy = sshbuf_fromb(buf)) == NULL) {
1053 r = SSH_ERR_ALLOC_FAIL;
1056 if ((r = sshbuf_consume(copy, sects_off)) != 0)
1058 while (sshbuf_len(copy) > 0) {
1061 if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
1062 (r = sshbuf_froms(copy, §)) != 0)
1064 KRL_DBG(("%s: second pass, section 0x%02x", __func__, type));
1067 case KRL_SECTION_CERTIFICATES:
1068 if ((r = parse_revoked_certs(sect, krl)) != 0)
1071 case KRL_SECTION_EXPLICIT_KEY:
1072 case KRL_SECTION_FINGERPRINT_SHA1:
1073 while (sshbuf_len(sect) > 0) {
1074 if ((r = sshbuf_get_string(sect,
1075 &rdata, &rlen)) != 0)
1077 if (type == KRL_SECTION_FINGERPRINT_SHA1 &&
1079 error("%s: bad SHA1 length", __func__);
1080 r = SSH_ERR_INVALID_FORMAT;
1083 if ((r = revoke_blob(
1084 type == KRL_SECTION_EXPLICIT_KEY ?
1085 &krl->revoked_keys : &krl->revoked_sha1s,
1088 rdata = NULL; /* revoke_blob frees rdata */
1091 case KRL_SECTION_SIGNATURE:
1092 /* Handled above, but still need to stay in synch */
1095 if ((r = sshbuf_skip_string(copy)) != 0)
1099 error("Unsupported KRL section %u", type);
1100 r = SSH_ERR_INVALID_FORMAT;
1103 if (sect != NULL && sshbuf_len(sect) > 0) {
1104 error("KRL section contains unparsed data");
1105 r = SSH_ERR_INVALID_FORMAT;
1110 /* Check that the key(s) used to sign the KRL weren't revoked */
1112 for (i = 0; i < nca_used; i++) {
1113 if (ssh_krl_check_key(krl, ca_used[i]) == 0)
1116 sshkey_free(ca_used[i]);
1120 if (nca_used && !sig_seen) {
1121 error("All keys used to sign KRL were revoked");
1122 r = SSH_ERR_KEY_REVOKED;
1126 /* If we have CA keys, then verify that one was used to sign the KRL */
1127 if (sig_seen && nsign_ca_keys != 0) {
1129 for (i = 0; !sig_seen && i < nsign_ca_keys; i++) {
1130 for (j = 0; j < nca_used; j++) {
1131 if (ca_used[j] == NULL)
1133 if (sshkey_equal(ca_used[j], sign_ca_keys[i])) {
1140 r = SSH_ERR_SIGNATURE_INVALID;
1141 error("KRL not signed with any trusted key");
1151 for (i = 0; i < nca_used; i++)
1152 sshkey_free(ca_used[i]);
1161 /* Checks certificate serial number and key ID revocation */
1163 is_cert_revoked(const struct sshkey *key, struct revoked_certs *rc)
1165 struct revoked_serial rs, *ers;
1166 struct revoked_key_id rki, *erki;
1168 /* Check revocation by cert key ID */
1169 memset(&rki, 0, sizeof(rki));
1170 rki.key_id = key->cert->key_id;
1171 erki = RB_FIND(revoked_key_id_tree, &rc->revoked_key_ids, &rki);
1173 KRL_DBG(("%s: revoked by key ID", __func__));
1174 return SSH_ERR_KEY_REVOKED;
1178 * Zero serials numbers are ignored (it's the default when the
1179 * CA doesn't specify one).
1181 if (key->cert->serial == 0)
1184 memset(&rs, 0, sizeof(rs));
1185 rs.lo = rs.hi = key->cert->serial;
1186 ers = RB_FIND(revoked_serial_tree, &rc->revoked_serials, &rs);
1188 KRL_DBG(("%s: revoked serial %llu matched %llu:%llu", __func__,
1189 key->cert->serial, ers->lo, ers->hi));
1190 return SSH_ERR_KEY_REVOKED;
1195 /* Checks whether a given key/cert is revoked. Does not check its CA */
1197 is_key_revoked(struct ssh_krl *krl, const struct sshkey *key)
1199 struct revoked_blob rb, *erb;
1200 struct revoked_certs *rc;
1203 /* Check explicitly revoked hashes first */
1204 memset(&rb, 0, sizeof(rb));
1205 if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
1206 &rb.blob, &rb.len)) != 0)
1208 erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha1s, &rb);
1211 KRL_DBG(("%s: revoked by key SHA1", __func__));
1212 return SSH_ERR_KEY_REVOKED;
1215 /* Next, explicit keys */
1216 memset(&rb, 0, sizeof(rb));
1217 if ((r = plain_key_blob(key, &rb.blob, &rb.len)) != 0)
1219 erb = RB_FIND(revoked_blob_tree, &krl->revoked_keys, &rb);
1222 KRL_DBG(("%s: revoked by explicit key", __func__));
1223 return SSH_ERR_KEY_REVOKED;
1226 if (!sshkey_is_cert(key))
1229 /* Check cert revocation for the specified CA */
1230 if ((r = revoked_certs_for_ca_key(krl, key->cert->signature_key,
1234 if ((r = is_cert_revoked(key, rc)) != 0)
1237 /* Check cert revocation for the wildcard CA */
1238 if ((r = revoked_certs_for_ca_key(krl, NULL, &rc, 0)) != 0)
1241 if ((r = is_cert_revoked(key, rc)) != 0)
1245 KRL_DBG(("%s: %llu no match", __func__, key->cert->serial));
1250 ssh_krl_check_key(struct ssh_krl *krl, const struct sshkey *key)
1254 KRL_DBG(("%s: checking key", __func__));
1255 if ((r = is_key_revoked(krl, key)) != 0)
1257 if (sshkey_is_cert(key)) {
1258 debug2("%s: checking CA key", __func__);
1259 if ((r = is_key_revoked(krl, key->cert->signature_key)) != 0)
1262 KRL_DBG(("%s: key okay", __func__));
1267 ssh_krl_file_contains_key(const char *path, const struct sshkey *key)
1269 struct sshbuf *krlbuf = NULL;
1270 struct ssh_krl *krl = NULL;
1271 int oerrno = 0, r, fd;
1276 if ((krlbuf = sshbuf_new()) == NULL)
1277 return SSH_ERR_ALLOC_FAIL;
1278 if ((fd = open(path, O_RDONLY)) == -1) {
1279 r = SSH_ERR_SYSTEM_ERROR;
1283 if ((r = sshkey_load_file(fd, krlbuf)) != 0) {
1287 if ((r = ssh_krl_from_blob(krlbuf, &krl, NULL, 0)) != 0)
1289 debug2("%s: checking KRL %s", __func__, path);
1290 r = ssh_krl_check_key(krl, key);
1293 sshbuf_free(krlbuf);