krl.c revision 1.1.1.4
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
17/* $OpenBSD: krl.c,v 1.31 2015/01/30 01:10:33 djm Exp $ */
18
19#include <sys/param.h>	/* MIN */
20#include <sys/types.h>
21#include <sys/tree.h>
22#include <sys/queue.h>
23
24#include <errno.h>
25#include <fcntl.h>
26#include <limits.h>
27#include <string.h>
28#include <time.h>
29#include <unistd.h>
30
31#include "sshbuf.h"
32#include "ssherr.h"
33#include "sshkey.h"
34#include "authfile.h"
35#include "misc.h"
36#include "log.h"
37#include "digest.h"
38#include "bitmap.h"
39
40#include "krl.h"
41
42/* #define DEBUG_KRL */
43#ifdef DEBUG_KRL
44# define KRL_DBG(x) debug3 x
45#else
46# define KRL_DBG(x)
47#endif
48
49/*
50 * Trees of revoked serial numbers, key IDs and keys. This allows
51 * quick searching, querying and producing lists in canonical order.
52 */
53
54/* Tree of serial numbers. XXX make smarter: really need a real sparse bitmap */
55struct revoked_serial {
56	u_int64_t lo, hi;
57	RB_ENTRY(revoked_serial) tree_entry;
58};
59static int serial_cmp(struct revoked_serial *a, struct revoked_serial *b);
60RB_HEAD(revoked_serial_tree, revoked_serial);
61RB_GENERATE_STATIC(revoked_serial_tree, revoked_serial, tree_entry, serial_cmp);
62
63/* Tree of key IDs */
64struct revoked_key_id {
65	char *key_id;
66	RB_ENTRY(revoked_key_id) tree_entry;
67};
68static int key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b);
69RB_HEAD(revoked_key_id_tree, revoked_key_id);
70RB_GENERATE_STATIC(revoked_key_id_tree, revoked_key_id, tree_entry, key_id_cmp);
71
72/* Tree of blobs (used for keys and fingerprints) */
73struct revoked_blob {
74	u_char *blob;
75	size_t len;
76	RB_ENTRY(revoked_blob) tree_entry;
77};
78static int blob_cmp(struct revoked_blob *a, struct revoked_blob *b);
79RB_HEAD(revoked_blob_tree, revoked_blob);
80RB_GENERATE_STATIC(revoked_blob_tree, revoked_blob, tree_entry, blob_cmp);
81
82/* Tracks revoked certs for a single CA */
83struct revoked_certs {
84	struct sshkey *ca_key;
85	struct revoked_serial_tree revoked_serials;
86	struct revoked_key_id_tree revoked_key_ids;
87	TAILQ_ENTRY(revoked_certs) entry;
88};
89TAILQ_HEAD(revoked_certs_list, revoked_certs);
90
91struct ssh_krl {
92	u_int64_t krl_version;
93	u_int64_t generated_date;
94	u_int64_t flags;
95	char *comment;
96	struct revoked_blob_tree revoked_keys;
97	struct revoked_blob_tree revoked_sha1s;
98	struct revoked_certs_list revoked_certs;
99};
100
101/* Return equal if a and b overlap */
102static int
103serial_cmp(struct revoked_serial *a, struct revoked_serial *b)
104{
105	if (a->hi >= b->lo && a->lo <= b->hi)
106		return 0;
107	return a->lo < b->lo ? -1 : 1;
108}
109
110static int
111key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b)
112{
113	return strcmp(a->key_id, b->key_id);
114}
115
116static int
117blob_cmp(struct revoked_blob *a, struct revoked_blob *b)
118{
119	int r;
120
121	if (a->len != b->len) {
122		if ((r = memcmp(a->blob, b->blob, MIN(a->len, b->len))) != 0)
123			return r;
124		return a->len > b->len ? 1 : -1;
125	} else
126		return memcmp(a->blob, b->blob, a->len);
127}
128
129struct ssh_krl *
130ssh_krl_init(void)
131{
132	struct ssh_krl *krl;
133
134	if ((krl = calloc(1, sizeof(*krl))) == NULL)
135		return NULL;
136	RB_INIT(&krl->revoked_keys);
137	RB_INIT(&krl->revoked_sha1s);
138	TAILQ_INIT(&krl->revoked_certs);
139	return krl;
140}
141
142static void
143revoked_certs_free(struct revoked_certs *rc)
144{
145	struct revoked_serial *rs, *trs;
146	struct revoked_key_id *rki, *trki;
147
148	RB_FOREACH_SAFE(rs, revoked_serial_tree, &rc->revoked_serials, trs) {
149		RB_REMOVE(revoked_serial_tree, &rc->revoked_serials, rs);
150		free(rs);
151	}
152	RB_FOREACH_SAFE(rki, revoked_key_id_tree, &rc->revoked_key_ids, trki) {
153		RB_REMOVE(revoked_key_id_tree, &rc->revoked_key_ids, rki);
154		free(rki->key_id);
155		free(rki);
156	}
157	sshkey_free(rc->ca_key);
158}
159
160void
161ssh_krl_free(struct ssh_krl *krl)
162{
163	struct revoked_blob *rb, *trb;
164	struct revoked_certs *rc, *trc;
165
166	if (krl == NULL)
167		return;
168
169	free(krl->comment);
170	RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_keys, trb) {
171		RB_REMOVE(revoked_blob_tree, &krl->revoked_keys, rb);
172		free(rb->blob);
173		free(rb);
174	}
175	RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha1s, trb) {
176		RB_REMOVE(revoked_blob_tree, &krl->revoked_sha1s, rb);
177		free(rb->blob);
178		free(rb);
179	}
180	TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) {
181		TAILQ_REMOVE(&krl->revoked_certs, rc, entry);
182		revoked_certs_free(rc);
183	}
184}
185
186void
187ssh_krl_set_version(struct ssh_krl *krl, u_int64_t version)
188{
189	krl->krl_version = version;
190}
191
192int
193ssh_krl_set_comment(struct ssh_krl *krl, const char *comment)
194{
195	free(krl->comment);
196	if ((krl->comment = strdup(comment)) == NULL)
197		return SSH_ERR_ALLOC_FAIL;
198	return 0;
199}
200
201/*
202 * Find the revoked_certs struct for a CA key. If allow_create is set then
203 * create a new one in the tree if one did not exist already.
204 */
205static int
206revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
207    struct revoked_certs **rcp, int allow_create)
208{
209	struct revoked_certs *rc;
210	int r;
211
212	*rcp = NULL;
213	TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
214		if ((ca_key == NULL && rc->ca_key == NULL) ||
215		    sshkey_equal(rc->ca_key, ca_key)) {
216			*rcp = rc;
217			return 0;
218		}
219	}
220	if (!allow_create)
221		return 0;
222	/* If this CA doesn't exist in the list then add it now */
223	if ((rc = calloc(1, sizeof(*rc))) == NULL)
224		return SSH_ERR_ALLOC_FAIL;
225	if (ca_key == NULL)
226		rc->ca_key = NULL;
227	else if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
228		free(rc);
229		return r;
230	}
231	RB_INIT(&rc->revoked_serials);
232	RB_INIT(&rc->revoked_key_ids);
233	TAILQ_INSERT_TAIL(&krl->revoked_certs, rc, entry);
234	KRL_DBG(("%s: new CA %s", __func__,
235	    ca_key == NULL ? "*" : sshkey_type(ca_key)));
236	*rcp = rc;
237	return 0;
238}
239
240static int
241insert_serial_range(struct revoked_serial_tree *rt, u_int64_t lo, u_int64_t hi)
242{
243	struct revoked_serial rs, *ers, *crs, *irs;
244
245	KRL_DBG(("%s: insert %llu:%llu", __func__, lo, hi));
246	memset(&rs, 0, sizeof(rs));
247	rs.lo = lo;
248	rs.hi = hi;
249	ers = RB_NFIND(revoked_serial_tree, rt, &rs);
250	if (ers == NULL || serial_cmp(ers, &rs) != 0) {
251		/* No entry matches. Just insert */
252		if ((irs = malloc(sizeof(rs))) == NULL)
253			return SSH_ERR_ALLOC_FAIL;
254		memcpy(irs, &rs, sizeof(*irs));
255		ers = RB_INSERT(revoked_serial_tree, rt, irs);
256		if (ers != NULL) {
257			KRL_DBG(("%s: bad: ers != NULL", __func__));
258			/* Shouldn't happen */
259			free(irs);
260			return SSH_ERR_INTERNAL_ERROR;
261		}
262		ers = irs;
263	} else {
264		KRL_DBG(("%s: overlap found %llu:%llu", __func__,
265		    ers->lo, ers->hi));
266		/*
267		 * The inserted entry overlaps an existing one. Grow the
268		 * existing entry.
269		 */
270		if (ers->lo > lo)
271			ers->lo = lo;
272		if (ers->hi < hi)
273			ers->hi = hi;
274	}
275
276	/*
277	 * The inserted or revised range might overlap or abut adjacent ones;
278	 * coalesce as necessary.
279	 */
280
281	/* Check predecessors */
282	while ((crs = RB_PREV(revoked_serial_tree, rt, ers)) != NULL) {
283		KRL_DBG(("%s: pred %llu:%llu", __func__, crs->lo, crs->hi));
284		if (ers->lo != 0 && crs->hi < ers->lo - 1)
285			break;
286		/* This entry overlaps. */
287		if (crs->lo < ers->lo) {
288			ers->lo = crs->lo;
289			KRL_DBG(("%s: pred extend %llu:%llu", __func__,
290			    ers->lo, ers->hi));
291		}
292		RB_REMOVE(revoked_serial_tree, rt, crs);
293		free(crs);
294	}
295	/* Check successors */
296	while ((crs = RB_NEXT(revoked_serial_tree, rt, ers)) != NULL) {
297		KRL_DBG(("%s: succ %llu:%llu", __func__, crs->lo, crs->hi));
298		if (ers->hi != (u_int64_t)-1 && crs->lo > ers->hi + 1)
299			break;
300		/* This entry overlaps. */
301		if (crs->hi > ers->hi) {
302			ers->hi = crs->hi;
303			KRL_DBG(("%s: succ extend %llu:%llu", __func__,
304			    ers->lo, ers->hi));
305		}
306		RB_REMOVE(revoked_serial_tree, rt, crs);
307		free(crs);
308	}
309	KRL_DBG(("%s: done, final %llu:%llu", __func__, ers->lo, ers->hi));
310	return 0;
311}
312
313int
314ssh_krl_revoke_cert_by_serial(struct ssh_krl *krl, const struct sshkey *ca_key,
315    u_int64_t serial)
316{
317	return ssh_krl_revoke_cert_by_serial_range(krl, ca_key, serial, serial);
318}
319
320int
321ssh_krl_revoke_cert_by_serial_range(struct ssh_krl *krl,
322    const struct sshkey *ca_key, u_int64_t lo, u_int64_t hi)
323{
324	struct revoked_certs *rc;
325	int r;
326
327	if (lo > hi || lo == 0)
328		return SSH_ERR_INVALID_ARGUMENT;
329	if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
330		return r;
331	return insert_serial_range(&rc->revoked_serials, lo, hi);
332}
333
334int
335ssh_krl_revoke_cert_by_key_id(struct ssh_krl *krl, const struct sshkey *ca_key,
336    const char *key_id)
337{
338	struct revoked_key_id *rki, *erki;
339	struct revoked_certs *rc;
340	int r;
341
342	if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
343		return r;
344
345	KRL_DBG(("%s: revoke %s", __func__, key_id));
346	if ((rki = calloc(1, sizeof(*rki))) == NULL ||
347	    (rki->key_id = strdup(key_id)) == NULL) {
348		free(rki);
349		return SSH_ERR_ALLOC_FAIL;
350	}
351	erki = RB_INSERT(revoked_key_id_tree, &rc->revoked_key_ids, rki);
352	if (erki != NULL) {
353		free(rki->key_id);
354		free(rki);
355	}
356	return 0;
357}
358
359/* Convert "key" to a public key blob without any certificate information */
360static int
361plain_key_blob(const struct sshkey *key, u_char **blob, size_t *blen)
362{
363	struct sshkey *kcopy;
364	int r;
365
366	if ((r = sshkey_from_private(key, &kcopy)) != 0)
367		return r;
368	if (sshkey_is_cert(kcopy)) {
369		if ((r = sshkey_drop_cert(kcopy)) != 0) {
370			sshkey_free(kcopy);
371			return r;
372		}
373	}
374	r = sshkey_to_blob(kcopy, blob, blen);
375	sshkey_free(kcopy);
376	return r;
377}
378
379/* Revoke a key blob. Ownership of blob is transferred to the tree */
380static int
381revoke_blob(struct revoked_blob_tree *rbt, u_char *blob, size_t len)
382{
383	struct revoked_blob *rb, *erb;
384
385	if ((rb = calloc(1, sizeof(*rb))) == NULL)
386		return SSH_ERR_ALLOC_FAIL;
387	rb->blob = blob;
388	rb->len = len;
389	erb = RB_INSERT(revoked_blob_tree, rbt, rb);
390	if (erb != NULL) {
391		free(rb->blob);
392		free(rb);
393	}
394	return 0;
395}
396
397int
398ssh_krl_revoke_key_explicit(struct ssh_krl *krl, const struct sshkey *key)
399{
400	u_char *blob;
401	size_t len;
402	int r;
403
404	debug3("%s: revoke type %s", __func__, sshkey_type(key));
405	if ((r = plain_key_blob(key, &blob, &len)) != 0)
406		return r;
407	return revoke_blob(&krl->revoked_keys, blob, len);
408}
409
410int
411ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const struct sshkey *key)
412{
413	u_char *blob;
414	size_t len;
415	int r;
416
417	debug3("%s: revoke type %s by sha1", __func__, sshkey_type(key));
418	if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
419	    &blob, &len)) != 0)
420		return r;
421	return revoke_blob(&krl->revoked_sha1s, blob, len);
422}
423
424int
425ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key)
426{
427	if (!sshkey_is_cert(key))
428		return ssh_krl_revoke_key_sha1(krl, key);
429
430	if (sshkey_cert_is_legacy(key) || key->cert->serial == 0) {
431		return ssh_krl_revoke_cert_by_key_id(krl,
432		    key->cert->signature_key,
433		    key->cert->key_id);
434	} else {
435		return ssh_krl_revoke_cert_by_serial(krl,
436		    key->cert->signature_key,
437		    key->cert->serial);
438	}
439}
440
441/*
442 * Select the most compact section type to emit next in a KRL based on
443 * the current section type, the run length of contiguous revoked serial
444 * numbers and the gaps from the last and to the next revoked serial.
445 * Applies a mostly-accurate bit cost model to select the section type
446 * that will minimise the size of the resultant KRL.
447 */
448static int
449choose_next_state(int current_state, u_int64_t contig, int final,
450    u_int64_t last_gap, u_int64_t next_gap, int *force_new_section)
451{
452	int new_state;
453	u_int64_t cost, cost_list, cost_range, cost_bitmap, cost_bitmap_restart;
454
455	/*
456	 * Avoid unsigned overflows.
457	 * The limits are high enough to avoid confusing the calculations.
458	 */
459	contig = MIN(contig, 1ULL<<31);
460	last_gap = MIN(last_gap, 1ULL<<31);
461	next_gap = MIN(next_gap, 1ULL<<31);
462
463	/*
464	 * Calculate the cost to switch from the current state to candidates.
465	 * NB. range sections only ever contain a single range, so their
466	 * switching cost is independent of the current_state.
467	 */
468	cost_list = cost_bitmap = cost_bitmap_restart = 0;
469	cost_range = 8;
470	switch (current_state) {
471	case KRL_SECTION_CERT_SERIAL_LIST:
472		cost_bitmap_restart = cost_bitmap = 8 + 64;
473		break;
474	case KRL_SECTION_CERT_SERIAL_BITMAP:
475		cost_list = 8;
476		cost_bitmap_restart = 8 + 64;
477		break;
478	case KRL_SECTION_CERT_SERIAL_RANGE:
479	case 0:
480		cost_bitmap_restart = cost_bitmap = 8 + 64;
481		cost_list = 8;
482	}
483
484	/* Estimate base cost in bits of each section type */
485	cost_list += 64 * contig + (final ? 0 : 8+64);
486	cost_range += (2 * 64) + (final ? 0 : 8+64);
487	cost_bitmap += last_gap + contig + (final ? 0 : MIN(next_gap, 8+64));
488	cost_bitmap_restart += contig + (final ? 0 : MIN(next_gap, 8+64));
489
490	/* Convert to byte costs for actual comparison */
491	cost_list = (cost_list + 7) / 8;
492	cost_bitmap = (cost_bitmap + 7) / 8;
493	cost_bitmap_restart = (cost_bitmap_restart + 7) / 8;
494	cost_range = (cost_range + 7) / 8;
495
496	/* Now pick the best choice */
497	*force_new_section = 0;
498	new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
499	cost = cost_bitmap;
500	if (cost_range < cost) {
501		new_state = KRL_SECTION_CERT_SERIAL_RANGE;
502		cost = cost_range;
503	}
504	if (cost_list < cost) {
505		new_state = KRL_SECTION_CERT_SERIAL_LIST;
506		cost = cost_list;
507	}
508	if (cost_bitmap_restart < cost) {
509		new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
510		*force_new_section = 1;
511		cost = cost_bitmap_restart;
512	}
513	KRL_DBG(("%s: contig %llu last_gap %llu next_gap %llu final %d, costs:"
514	    "list %llu range %llu bitmap %llu new bitmap %llu, "
515	    "selected 0x%02x%s", __func__, (long long unsigned)contig,
516	    (long long unsigned)last_gap, (long long unsigned)next_gap, final,
517	    (long long unsigned)cost_list, (long long unsigned)cost_range,
518	    (long long unsigned)cost_bitmap,
519	    (long long unsigned)cost_bitmap_restart, new_state,
520	    *force_new_section ? " restart" : ""));
521	return new_state;
522}
523
524static int
525put_bitmap(struct sshbuf *buf, struct bitmap *bitmap)
526{
527	size_t len;
528	u_char *blob;
529	int r;
530
531	len = bitmap_nbytes(bitmap);
532	if ((blob = malloc(len)) == NULL)
533		return SSH_ERR_ALLOC_FAIL;
534	if (bitmap_to_string(bitmap, blob, len) != 0) {
535		free(blob);
536		return SSH_ERR_INTERNAL_ERROR;
537	}
538	r = sshbuf_put_bignum2_bytes(buf, blob, len);
539	free(blob);
540	return r;
541}
542
543/* Generate a KRL_SECTION_CERTIFICATES KRL section */
544static int
545revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
546{
547	int final, force_new_sect, r = SSH_ERR_INTERNAL_ERROR;
548	u_int64_t i, contig, gap, last = 0, bitmap_start = 0;
549	struct revoked_serial *rs, *nrs;
550	struct revoked_key_id *rki;
551	int next_state, state = 0;
552	struct sshbuf *sect;
553	struct bitmap *bitmap = NULL;
554
555	if ((sect = sshbuf_new()) == NULL)
556		return SSH_ERR_ALLOC_FAIL;
557
558	/* Store the header: optional CA scope key, reserved */
559	if (rc->ca_key == NULL) {
560		if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
561			goto out;
562	} else {
563		if ((r = sshkey_puts(rc->ca_key, buf)) != 0)
564			goto out;
565	}
566	if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
567		goto out;
568
569	/* Store the revoked serials.  */
570	for (rs = RB_MIN(revoked_serial_tree, &rc->revoked_serials);
571	     rs != NULL;
572	     rs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs)) {
573		KRL_DBG(("%s: serial %llu:%llu state 0x%02x", __func__,
574		    (long long unsigned)rs->lo, (long long unsigned)rs->hi,
575		    state));
576
577		/* Check contiguous length and gap to next section (if any) */
578		nrs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs);
579		final = nrs == NULL;
580		gap = nrs == NULL ? 0 : nrs->lo - rs->hi;
581		contig = 1 + (rs->hi - rs->lo);
582
583		/* Choose next state based on these */
584		next_state = choose_next_state(state, contig, final,
585		    state == 0 ? 0 : rs->lo - last, gap, &force_new_sect);
586
587		/*
588		 * If the current section is a range section or has a different
589		 * type to the next section, then finish it off now.
590		 */
591		if (state != 0 && (force_new_sect || next_state != state ||
592		    state == KRL_SECTION_CERT_SERIAL_RANGE)) {
593			KRL_DBG(("%s: finish state 0x%02x", __func__, state));
594			switch (state) {
595			case KRL_SECTION_CERT_SERIAL_LIST:
596			case KRL_SECTION_CERT_SERIAL_RANGE:
597				break;
598			case KRL_SECTION_CERT_SERIAL_BITMAP:
599				if ((r = put_bitmap(sect, bitmap)) != 0)
600					goto out;
601				bitmap_free(bitmap);
602				bitmap = NULL;
603				break;
604			}
605			if ((r = sshbuf_put_u8(buf, state)) != 0 ||
606			    (r = sshbuf_put_stringb(buf, sect)) != 0)
607				goto out;
608			sshbuf_reset(sect);
609		}
610
611		/* If we are starting a new section then prepare it now */
612		if (next_state != state || force_new_sect) {
613			KRL_DBG(("%s: start state 0x%02x", __func__,
614			    next_state));
615			state = next_state;
616			sshbuf_reset(sect);
617			switch (state) {
618			case KRL_SECTION_CERT_SERIAL_LIST:
619			case KRL_SECTION_CERT_SERIAL_RANGE:
620				break;
621			case KRL_SECTION_CERT_SERIAL_BITMAP:
622				if ((bitmap = bitmap_new()) == NULL) {
623					r = SSH_ERR_ALLOC_FAIL;
624					goto out;
625				}
626				bitmap_start = rs->lo;
627				if ((r = sshbuf_put_u64(sect,
628				    bitmap_start)) != 0)
629					goto out;
630				break;
631			}
632		}
633
634		/* Perform section-specific processing */
635		switch (state) {
636		case KRL_SECTION_CERT_SERIAL_LIST:
637			for (i = 0; i < contig; i++) {
638				if ((r = sshbuf_put_u64(sect, rs->lo + i)) != 0)
639					goto out;
640			}
641			break;
642		case KRL_SECTION_CERT_SERIAL_RANGE:
643			if ((r = sshbuf_put_u64(sect, rs->lo)) != 0 ||
644			    (r = sshbuf_put_u64(sect, rs->hi)) != 0)
645				goto out;
646			break;
647		case KRL_SECTION_CERT_SERIAL_BITMAP:
648			if (rs->lo - bitmap_start > INT_MAX) {
649				error("%s: insane bitmap gap", __func__);
650				goto out;
651			}
652			for (i = 0; i < contig; i++) {
653				if (bitmap_set_bit(bitmap,
654				    rs->lo + i - bitmap_start) != 0) {
655					r = SSH_ERR_ALLOC_FAIL;
656					goto out;
657				}
658			}
659			break;
660		}
661		last = rs->hi;
662	}
663	/* Flush the remaining section, if any */
664	if (state != 0) {
665		KRL_DBG(("%s: serial final flush for state 0x%02x",
666		    __func__, state));
667		switch (state) {
668		case KRL_SECTION_CERT_SERIAL_LIST:
669		case KRL_SECTION_CERT_SERIAL_RANGE:
670			break;
671		case KRL_SECTION_CERT_SERIAL_BITMAP:
672			if ((r = put_bitmap(sect, bitmap)) != 0)
673				goto out;
674			bitmap_free(bitmap);
675			bitmap = NULL;
676			break;
677		}
678		if ((r = sshbuf_put_u8(buf, state)) != 0 ||
679		    (r = sshbuf_put_stringb(buf, sect)) != 0)
680			goto out;
681	}
682	KRL_DBG(("%s: serial done ", __func__));
683
684	/* Now output a section for any revocations by key ID */
685	sshbuf_reset(sect);
686	RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) {
687		KRL_DBG(("%s: key ID %s", __func__, rki->key_id));
688		if ((r = sshbuf_put_cstring(sect, rki->key_id)) != 0)
689			goto out;
690	}
691	if (sshbuf_len(sect) != 0) {
692		if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERT_KEY_ID)) != 0 ||
693		    (r = sshbuf_put_stringb(buf, sect)) != 0)
694			goto out;
695	}
696	r = 0;
697 out:
698	bitmap_free(bitmap);
699	sshbuf_free(sect);
700	return r;
701}
702
703int
704ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf,
705    const struct sshkey **sign_keys, u_int nsign_keys)
706{
707	int r = SSH_ERR_INTERNAL_ERROR;
708	struct revoked_certs *rc;
709	struct revoked_blob *rb;
710	struct sshbuf *sect;
711	u_char *sblob = NULL;
712	size_t slen, i;
713
714	if (krl->generated_date == 0)
715		krl->generated_date = time(NULL);
716
717	if ((sect = sshbuf_new()) == NULL)
718		return SSH_ERR_ALLOC_FAIL;
719
720	/* Store the header */
721	if ((r = sshbuf_put(buf, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0 ||
722	    (r = sshbuf_put_u32(buf, KRL_FORMAT_VERSION)) != 0 ||
723	    (r = sshbuf_put_u64(buf, krl->krl_version)) != 0 ||
724	    (r = sshbuf_put_u64(buf, krl->generated_date) != 0) ||
725	    (r = sshbuf_put_u64(buf, krl->flags)) != 0 ||
726	    (r = sshbuf_put_string(buf, NULL, 0)) != 0 ||
727	    (r = sshbuf_put_cstring(buf, krl->comment)) != 0)
728		goto out;
729
730	/* Store sections for revoked certificates */
731	TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
732		sshbuf_reset(sect);
733		if ((r = revoked_certs_generate(rc, sect)) != 0)
734			goto out;
735		if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERTIFICATES)) != 0 ||
736		    (r = sshbuf_put_stringb(buf, sect)) != 0)
737			goto out;
738	}
739
740	/* Finally, output sections for revocations by public key/hash */
741	sshbuf_reset(sect);
742	RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) {
743		KRL_DBG(("%s: key len %zu ", __func__, rb->len));
744		if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
745			goto out;
746	}
747	if (sshbuf_len(sect) != 0) {
748		if ((r = sshbuf_put_u8(buf, KRL_SECTION_EXPLICIT_KEY)) != 0 ||
749		    (r = sshbuf_put_stringb(buf, sect)) != 0)
750			goto out;
751	}
752	sshbuf_reset(sect);
753	RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) {
754		KRL_DBG(("%s: hash len %zu ", __func__, rb->len));
755		if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
756			goto out;
757	}
758	if (sshbuf_len(sect) != 0) {
759		if ((r = sshbuf_put_u8(buf,
760		    KRL_SECTION_FINGERPRINT_SHA1)) != 0 ||
761		    (r = sshbuf_put_stringb(buf, sect)) != 0)
762			goto out;
763	}
764
765	for (i = 0; i < nsign_keys; i++) {
766		KRL_DBG(("%s: signature key %s", __func__,
767		    sshkey_ssh_name(sign_keys[i])));
768		if ((r = sshbuf_put_u8(buf, KRL_SECTION_SIGNATURE)) != 0 ||
769		    (r = sshkey_puts(sign_keys[i], buf)) != 0)
770			goto out;
771
772		if ((r = sshkey_sign(sign_keys[i], &sblob, &slen,
773		    sshbuf_ptr(buf), sshbuf_len(buf), 0)) == -1)
774			goto out;
775		KRL_DBG(("%s: signature sig len %zu", __func__, slen));
776		if ((r = sshbuf_put_string(buf, sblob, slen)) != 0)
777			goto out;
778	}
779
780	r = 0;
781 out:
782	free(sblob);
783	sshbuf_free(sect);
784	return r;
785}
786
787static void
788format_timestamp(u_int64_t timestamp, char *ts, size_t nts)
789{
790	time_t t;
791	struct tm *tm;
792
793	t = timestamp;
794	tm = localtime(&t);
795	if (tm == NULL)
796		strlcpy(ts, "<INVALID>", nts);
797	else {
798		*ts = '\0';
799		strftime(ts, nts, "%Y%m%dT%H%M%S", tm);
800	}
801}
802
803static int
804parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
805{
806	int r = SSH_ERR_INTERNAL_ERROR;
807	u_char type;
808	const u_char *blob;
809	size_t blen, nbits;
810	struct sshbuf *subsect = NULL;
811	u_int64_t serial, serial_lo, serial_hi;
812	struct bitmap *bitmap = NULL;
813	char *key_id = NULL;
814	struct sshkey *ca_key = NULL;
815
816	if ((subsect = sshbuf_new()) == NULL)
817		return SSH_ERR_ALLOC_FAIL;
818
819	/* Header: key, reserved */
820	if ((r = sshbuf_get_string_direct(buf, &blob, &blen)) != 0 ||
821	    (r = sshbuf_skip_string(buf)) != 0)
822		goto out;
823	if (blen != 0 && (r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
824		goto out;
825
826	while (sshbuf_len(buf) > 0) {
827		if (subsect != NULL) {
828			sshbuf_free(subsect);
829			subsect = NULL;
830		}
831		if ((r = sshbuf_get_u8(buf, &type)) != 0 ||
832		    (r = sshbuf_froms(buf, &subsect)) != 0)
833			goto out;
834		KRL_DBG(("%s: subsection type 0x%02x", __func__, type));
835		/* sshbuf_dump(subsect, stderr); */
836
837		switch (type) {
838		case KRL_SECTION_CERT_SERIAL_LIST:
839			while (sshbuf_len(subsect) > 0) {
840				if ((r = sshbuf_get_u64(subsect, &serial)) != 0)
841					goto out;
842				if ((r = ssh_krl_revoke_cert_by_serial(krl,
843				    ca_key, serial)) != 0)
844					goto out;
845			}
846			break;
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)
850				goto out;
851			if ((r = ssh_krl_revoke_cert_by_serial_range(krl,
852			    ca_key, serial_lo, serial_hi)) != 0)
853				goto out;
854			break;
855		case KRL_SECTION_CERT_SERIAL_BITMAP:
856			if ((bitmap = bitmap_new()) == NULL) {
857				r = SSH_ERR_ALLOC_FAIL;
858				goto out;
859			}
860			if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
861			    (r = sshbuf_get_bignum2_bytes_direct(subsect,
862			    &blob, &blen)) != 0)
863				goto out;
864			if (bitmap_from_string(bitmap, blob, blen) != 0) {
865				r = SSH_ERR_INVALID_FORMAT;
866				goto out;
867			}
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;
873					goto out;
874				}
875				if (!bitmap_test_bit(bitmap, serial))
876					continue;
877				if ((r = ssh_krl_revoke_cert_by_serial(krl,
878				    ca_key, serial_lo + serial)) != 0)
879					goto out;
880			}
881			bitmap_free(bitmap);
882			bitmap = NULL;
883			break;
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)
888					goto out;
889				if ((r = ssh_krl_revoke_cert_by_key_id(krl,
890				    ca_key, key_id)) != 0)
891					goto out;
892				free(key_id);
893				key_id = NULL;
894			}
895			break;
896		default:
897			error("Unsupported KRL certificate section %u", type);
898			r = SSH_ERR_INVALID_FORMAT;
899			goto out;
900		}
901		if (sshbuf_len(subsect) > 0) {
902			error("KRL certificate section contains unparsed data");
903			r = SSH_ERR_INVALID_FORMAT;
904			goto out;
905		}
906	}
907
908	r = 0;
909 out:
910	if (bitmap != NULL)
911		bitmap_free(bitmap);
912	free(key_id);
913	sshkey_free(ca_key);
914	sshbuf_free(subsect);
915	return r;
916}
917
918
919/* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */
920int
921ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
922    const struct sshkey **sign_ca_keys, size_t nsign_ca_keys)
923{
924	struct sshbuf *copy = NULL, *sect = NULL;
925	struct ssh_krl *krl = NULL;
926	char timestamp[64];
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;
930	const u_char *blob;
931	size_t i, j, sig_off, sects_off, rlen, blen, nca_used;
932	u_int format_version;
933
934	nca_used = 0;
935	*krlp = NULL;
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;
940	}
941
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;
945		goto out;
946	}
947	if ((r = sshbuf_consume(copy, sizeof(KRL_MAGIC) - 1)) != 0)
948		goto out;
949
950	if ((krl = ssh_krl_init()) == NULL) {
951		error("%s: alloc failed", __func__);
952		goto out;
953	}
954
955	if ((r = sshbuf_get_u32(copy, &format_version)) != 0)
956		goto out;
957	if (format_version != KRL_FORMAT_VERSION) {
958		r = SSH_ERR_INVALID_FORMAT;
959		goto out;
960	}
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)
966		goto out;
967
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);
972
973	/*
974	 * 1st pass: verify signatures, if any. This is done to avoid
975	 * detailed parsing of data whose provenance is unverified.
976	 */
977	sig_seen = 0;
978	if (sshbuf_len(buf) < sshbuf_len(copy)) {
979		/* Shouldn't happen */
980		r = SSH_ERR_INTERNAL_ERROR;
981		goto out;
982	}
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)
987			goto out;
988		KRL_DBG(("%s: first pass, section 0x%02x", __func__, type));
989		if (type != KRL_SECTION_SIGNATURE) {
990			if (sig_seen) {
991				error("KRL contains non-signature section "
992				    "after signature");
993				r = SSH_ERR_INVALID_FORMAT;
994				goto out;
995			}
996			/* Not interested for now. */
997			continue;
998		}
999		sig_seen = 1;
1000		/* First string component is the signing key */
1001		if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
1002			r = SSH_ERR_INVALID_FORMAT;
1003			goto out;
1004		}
1005		if (sshbuf_len(buf) < sshbuf_len(copy)) {
1006			/* Shouldn't happen */
1007			r = SSH_ERR_INTERNAL_ERROR;
1008			goto out;
1009		}
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;
1014			goto out;
1015		}
1016		/* Check signature over entire KRL up to this point */
1017		if ((r = sshkey_verify(key, blob, blen,
1018		    sshbuf_ptr(buf), sshbuf_len(buf) - sig_off, 0)) != 0)
1019			goto out;
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 "
1024				    "the same key");
1025				r = SSH_ERR_INVALID_FORMAT;
1026				goto out;
1027			}
1028		}
1029		/* Record keys used to sign the KRL */
1030		tmp_ca_used = reallocarray(ca_used, nca_used + 1,
1031		    sizeof(*ca_used));
1032		if (tmp_ca_used == NULL) {
1033			r = SSH_ERR_ALLOC_FAIL;
1034			goto out;
1035		}
1036		ca_used = tmp_ca_used;
1037		ca_used[nca_used++] = key;
1038		key = NULL;
1039		break;
1040	}
1041
1042	if (sshbuf_len(copy) != 0) {
1043		/* Shouldn't happen */
1044		r = SSH_ERR_INTERNAL_ERROR;
1045		goto out;
1046	}
1047
1048	/*
1049	 * 2nd pass: parse and load the KRL, skipping the header to the point
1050	 * where the section start.
1051	 */
1052	sshbuf_free(copy);
1053	if ((copy = sshbuf_fromb(buf)) == NULL) {
1054		r = SSH_ERR_ALLOC_FAIL;
1055		goto out;
1056	}
1057	if ((r = sshbuf_consume(copy, sects_off)) != 0)
1058		goto out;
1059	while (sshbuf_len(copy) > 0) {
1060		if (sect != NULL) {
1061			sshbuf_free(sect);
1062			sect = NULL;
1063		}
1064		if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
1065		    (r = sshbuf_froms(copy, &sect)) != 0)
1066			goto out;
1067		KRL_DBG(("%s: second pass, section 0x%02x", __func__, type));
1068
1069		switch (type) {
1070		case KRL_SECTION_CERTIFICATES:
1071			if ((r = parse_revoked_certs(sect, krl)) != 0)
1072				goto out;
1073			break;
1074		case KRL_SECTION_EXPLICIT_KEY:
1075		case KRL_SECTION_FINGERPRINT_SHA1:
1076			while (sshbuf_len(sect) > 0) {
1077				if ((r = sshbuf_get_string(sect,
1078				    &rdata, &rlen)) != 0)
1079					goto out;
1080				if (type == KRL_SECTION_FINGERPRINT_SHA1 &&
1081				    rlen != 20) {
1082					error("%s: bad SHA1 length", __func__);
1083					r = SSH_ERR_INVALID_FORMAT;
1084					goto out;
1085				}
1086				if ((r = revoke_blob(
1087				    type == KRL_SECTION_EXPLICIT_KEY ?
1088				    &krl->revoked_keys : &krl->revoked_sha1s,
1089				    rdata, rlen)) != 0)
1090					goto out;
1091				rdata = NULL; /* revoke_blob frees rdata */
1092			}
1093			break;
1094		case KRL_SECTION_SIGNATURE:
1095			/* Handled above, but still need to stay in synch */
1096			sshbuf_reset(sect);
1097			sect = NULL;
1098			if ((r = sshbuf_skip_string(copy)) != 0)
1099				goto out;
1100			break;
1101		default:
1102			error("Unsupported KRL section %u", type);
1103			r = SSH_ERR_INVALID_FORMAT;
1104			goto out;
1105		}
1106		if (sshbuf_len(sect) > 0) {
1107			error("KRL section contains unparsed data");
1108			r = SSH_ERR_INVALID_FORMAT;
1109			goto out;
1110		}
1111	}
1112
1113	/* Check that the key(s) used to sign the KRL weren't revoked */
1114	sig_seen = 0;
1115	for (i = 0; i < nca_used; i++) {
1116		if (ssh_krl_check_key(krl, ca_used[i]) == 0)
1117			sig_seen = 1;
1118		else {
1119			sshkey_free(ca_used[i]);
1120			ca_used[i] = NULL;
1121		}
1122	}
1123	if (nca_used && !sig_seen) {
1124		error("All keys used to sign KRL were revoked");
1125		r = SSH_ERR_KEY_REVOKED;
1126		goto out;
1127	}
1128
1129	/* If we have CA keys, then verify that one was used to sign the KRL */
1130	if (sig_seen && nsign_ca_keys != 0) {
1131		sig_seen = 0;
1132		for (i = 0; !sig_seen && i < nsign_ca_keys; i++) {
1133			for (j = 0; j < nca_used; j++) {
1134				if (ca_used[j] == NULL)
1135					continue;
1136				if (sshkey_equal(ca_used[j], sign_ca_keys[i])) {
1137					sig_seen = 1;
1138					break;
1139				}
1140			}
1141		}
1142		if (!sig_seen) {
1143			r = SSH_ERR_SIGNATURE_INVALID;
1144			error("KRL not signed with any trusted key");
1145			goto out;
1146		}
1147	}
1148
1149	*krlp = krl;
1150	r = 0;
1151 out:
1152	if (r != 0)
1153		ssh_krl_free(krl);
1154	for (i = 0; i < nca_used; i++)
1155		sshkey_free(ca_used[i]);
1156	free(ca_used);
1157	free(rdata);
1158	sshkey_free(key);
1159	sshbuf_free(copy);
1160	sshbuf_free(sect);
1161	return r;
1162}
1163
1164/* Checks certificate serial number and key ID revocation */
1165static int
1166is_cert_revoked(const struct sshkey *key, struct revoked_certs *rc)
1167{
1168	struct revoked_serial rs, *ers;
1169	struct revoked_key_id rki, *erki;
1170
1171	/* Check revocation by cert key ID */
1172	memset(&rki, 0, sizeof(rki));
1173	rki.key_id = key->cert->key_id;
1174	erki = RB_FIND(revoked_key_id_tree, &rc->revoked_key_ids, &rki);
1175	if (erki != NULL) {
1176		KRL_DBG(("%s: revoked by key ID", __func__));
1177		return SSH_ERR_KEY_REVOKED;
1178	}
1179
1180	/*
1181	 * Legacy cert formats lack serial numbers. Zero serials numbers
1182	 * are ignored (it's the default when the CA doesn't specify one).
1183	 */
1184	if (sshkey_cert_is_legacy(key) || key->cert->serial == 0)
1185		return 0;
1186
1187	memset(&rs, 0, sizeof(rs));
1188	rs.lo = rs.hi = key->cert->serial;
1189	ers = RB_FIND(revoked_serial_tree, &rc->revoked_serials, &rs);
1190	if (ers != NULL) {
1191		KRL_DBG(("%s: revoked serial %llu matched %llu:%llu", __func__,
1192		    key->cert->serial, ers->lo, ers->hi));
1193		return SSH_ERR_KEY_REVOKED;
1194	}
1195	return 0;
1196}
1197
1198/* Checks whether a given key/cert is revoked. Does not check its CA */
1199static int
1200is_key_revoked(struct ssh_krl *krl, const struct sshkey *key)
1201{
1202	struct revoked_blob rb, *erb;
1203	struct revoked_certs *rc;
1204	int r;
1205
1206	/* Check explicitly revoked hashes first */
1207	memset(&rb, 0, sizeof(rb));
1208	if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
1209	    &rb.blob, &rb.len)) != 0)
1210		return r;
1211	erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha1s, &rb);
1212	free(rb.blob);
1213	if (erb != NULL) {
1214		KRL_DBG(("%s: revoked by key SHA1", __func__));
1215		return SSH_ERR_KEY_REVOKED;
1216	}
1217
1218	/* Next, explicit keys */
1219	memset(&rb, 0, sizeof(rb));
1220	if ((r = plain_key_blob(key, &rb.blob, &rb.len)) != 0)
1221		return r;
1222	erb = RB_FIND(revoked_blob_tree, &krl->revoked_keys, &rb);
1223	free(rb.blob);
1224	if (erb != NULL) {
1225		KRL_DBG(("%s: revoked by explicit key", __func__));
1226		return SSH_ERR_KEY_REVOKED;
1227	}
1228
1229	if (!sshkey_is_cert(key))
1230		return 0;
1231
1232	/* Check cert revocation for the specified CA */
1233	if ((r = revoked_certs_for_ca_key(krl, key->cert->signature_key,
1234	    &rc, 0)) != 0)
1235		return r;
1236	if (rc != NULL) {
1237		if ((r = is_cert_revoked(key, rc)) != 0)
1238			return r;
1239	}
1240	/* Check cert revocation for the wildcard CA */
1241	if ((r = revoked_certs_for_ca_key(krl, NULL, &rc, 0)) != 0)
1242		return r;
1243	if (rc != NULL) {
1244		if ((r = is_cert_revoked(key, rc)) != 0)
1245			return r;
1246	}
1247
1248	KRL_DBG(("%s: %llu no match", __func__, key->cert->serial));
1249	return 0;
1250}
1251
1252int
1253ssh_krl_check_key(struct ssh_krl *krl, const struct sshkey *key)
1254{
1255	int r;
1256
1257	KRL_DBG(("%s: checking key", __func__));
1258	if ((r = is_key_revoked(krl, key)) != 0)
1259		return r;
1260	if (sshkey_is_cert(key)) {
1261		debug2("%s: checking CA key", __func__);
1262		if ((r = is_key_revoked(krl, key->cert->signature_key)) != 0)
1263			return r;
1264	}
1265	KRL_DBG(("%s: key okay", __func__));
1266	return 0;
1267}
1268
1269int
1270ssh_krl_file_contains_key(const char *path, const struct sshkey *key)
1271{
1272	struct sshbuf *krlbuf = NULL;
1273	struct ssh_krl *krl = NULL;
1274	int oerrno = 0, r, fd;
1275
1276	if (path == NULL)
1277		return 0;
1278
1279	if ((krlbuf = sshbuf_new()) == NULL)
1280		return SSH_ERR_ALLOC_FAIL;
1281	if ((fd = open(path, O_RDONLY)) == -1) {
1282		r = SSH_ERR_SYSTEM_ERROR;
1283		oerrno = errno;
1284		goto out;
1285	}
1286	if ((r = sshkey_load_file(fd, krlbuf)) != 0) {
1287		oerrno = errno;
1288		goto out;
1289	}
1290	if ((r = ssh_krl_from_blob(krlbuf, &krl, NULL, 0)) != 0)
1291		goto out;
1292	debug2("%s: checking KRL %s", __func__, path);
1293	r = ssh_krl_check_key(krl, key);
1294 out:
1295	close(fd);
1296	sshbuf_free(krlbuf);
1297	ssh_krl_free(krl);
1298	if (r != 0)
1299		errno = oerrno;
1300	return r;
1301}
1302