/
krl.c
1532 lines (1411 loc) · 39.5 KB
/
krl.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (c) 2012 Damien Miller <djm@mindrot.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $OpenBSD: krl.c,v 1.56 2023/07/17 03:57:21 djm Exp $ */
#include "includes.h"
#include <sys/types.h>
#include <openbsd-compat/sys-tree.h>
#include <openbsd-compat/sys-queue.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "sshbuf.h"
#include "ssherr.h"
#include "sshkey.h"
#include "authfile.h"
#include "misc.h"
#include "log.h"
#include "digest.h"
#include "bitmap.h"
#include "utf8.h"
#include "krl.h"
/* #define DEBUG_KRL */
#ifdef DEBUG_KRL
# define KRL_DBG(x) debug3_f x
#else
# define KRL_DBG(x)
#endif
/*
* Trees of revoked serial numbers, key IDs and keys. This allows
* quick searching, querying and producing lists in canonical order.
*/
/* Tree of serial numbers. XXX make smarter: really need a real sparse bitmap */
struct revoked_serial {
u_int64_t lo, hi;
RB_ENTRY(revoked_serial) tree_entry;
};
static int serial_cmp(struct revoked_serial *a, struct revoked_serial *b);
RB_HEAD(revoked_serial_tree, revoked_serial);
RB_GENERATE_STATIC(revoked_serial_tree, revoked_serial, tree_entry, serial_cmp)
/* Tree of key IDs */
struct revoked_key_id {
char *key_id;
RB_ENTRY(revoked_key_id) tree_entry;
};
static int key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b);
RB_HEAD(revoked_key_id_tree, revoked_key_id);
RB_GENERATE_STATIC(revoked_key_id_tree, revoked_key_id, tree_entry, key_id_cmp)
/* Tree of blobs (used for keys and fingerprints) */
struct revoked_blob {
u_char *blob;
size_t len;
RB_ENTRY(revoked_blob) tree_entry;
};
static int blob_cmp(struct revoked_blob *a, struct revoked_blob *b);
RB_HEAD(revoked_blob_tree, revoked_blob);
RB_GENERATE_STATIC(revoked_blob_tree, revoked_blob, tree_entry, blob_cmp)
/* Tracks revoked certs for a single CA */
struct revoked_certs {
struct sshkey *ca_key;
struct revoked_serial_tree revoked_serials;
struct revoked_key_id_tree revoked_key_ids;
TAILQ_ENTRY(revoked_certs) entry;
};
TAILQ_HEAD(revoked_certs_list, revoked_certs);
struct ssh_krl {
u_int64_t krl_version;
u_int64_t generated_date;
u_int64_t flags;
char *comment;
struct revoked_blob_tree revoked_keys;
struct revoked_blob_tree revoked_sha1s;
struct revoked_blob_tree revoked_sha256s;
struct revoked_certs_list revoked_certs;
};
/* Return equal if a and b overlap */
static int
serial_cmp(struct revoked_serial *a, struct revoked_serial *b)
{
if (a->hi >= b->lo && a->lo <= b->hi)
return 0;
return a->lo < b->lo ? -1 : 1;
}
static int
key_id_cmp(struct revoked_key_id *a, struct revoked_key_id *b)
{
return strcmp(a->key_id, b->key_id);
}
static int
blob_cmp(struct revoked_blob *a, struct revoked_blob *b)
{
int r;
if (a->len != b->len) {
if ((r = memcmp(a->blob, b->blob, MINIMUM(a->len, b->len))) != 0)
return r;
return a->len > b->len ? 1 : -1;
} else
return memcmp(a->blob, b->blob, a->len);
}
struct ssh_krl *
ssh_krl_init(void)
{
struct ssh_krl *krl;
if ((krl = calloc(1, sizeof(*krl))) == NULL)
return NULL;
RB_INIT(&krl->revoked_keys);
RB_INIT(&krl->revoked_sha1s);
RB_INIT(&krl->revoked_sha256s);
TAILQ_INIT(&krl->revoked_certs);
return krl;
}
static void
revoked_certs_free(struct revoked_certs *rc)
{
struct revoked_serial *rs, *trs;
struct revoked_key_id *rki, *trki;
RB_FOREACH_SAFE(rs, revoked_serial_tree, &rc->revoked_serials, trs) {
RB_REMOVE(revoked_serial_tree, &rc->revoked_serials, rs);
free(rs);
}
RB_FOREACH_SAFE(rki, revoked_key_id_tree, &rc->revoked_key_ids, trki) {
RB_REMOVE(revoked_key_id_tree, &rc->revoked_key_ids, rki);
free(rki->key_id);
free(rki);
}
sshkey_free(rc->ca_key);
}
void
ssh_krl_free(struct ssh_krl *krl)
{
struct revoked_blob *rb, *trb;
struct revoked_certs *rc, *trc;
if (krl == NULL)
return;
free(krl->comment);
RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_keys, trb) {
RB_REMOVE(revoked_blob_tree, &krl->revoked_keys, rb);
free(rb->blob);
free(rb);
}
RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha1s, trb) {
RB_REMOVE(revoked_blob_tree, &krl->revoked_sha1s, rb);
free(rb->blob);
free(rb);
}
RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha256s, trb) {
RB_REMOVE(revoked_blob_tree, &krl->revoked_sha256s, rb);
free(rb->blob);
free(rb);
}
TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) {
TAILQ_REMOVE(&krl->revoked_certs, rc, entry);
revoked_certs_free(rc);
}
free(krl);
}
void
ssh_krl_set_version(struct ssh_krl *krl, u_int64_t version)
{
krl->krl_version = version;
}
int
ssh_krl_set_comment(struct ssh_krl *krl, const char *comment)
{
free(krl->comment);
if ((krl->comment = strdup(comment)) == NULL)
return SSH_ERR_ALLOC_FAIL;
return 0;
}
/*
* Find the revoked_certs struct for a CA key. If allow_create is set then
* create a new one in the tree if one did not exist already.
*/
static int
revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
struct revoked_certs **rcp, int allow_create)
{
struct revoked_certs *rc;
int r;
*rcp = NULL;
TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
if ((ca_key == NULL && rc->ca_key == NULL) ||
sshkey_equal(rc->ca_key, ca_key)) {
*rcp = rc;
return 0;
}
}
if (!allow_create)
return 0;
/* If this CA doesn't exist in the list then add it now */
if ((rc = calloc(1, sizeof(*rc))) == NULL)
return SSH_ERR_ALLOC_FAIL;
if (ca_key == NULL)
rc->ca_key = NULL;
else if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
free(rc);
return r;
}
RB_INIT(&rc->revoked_serials);
RB_INIT(&rc->revoked_key_ids);
TAILQ_INSERT_TAIL(&krl->revoked_certs, rc, entry);
KRL_DBG(("new CA %s", ca_key == NULL ? "*" : sshkey_type(ca_key)));
*rcp = rc;
return 0;
}
static int
insert_serial_range(struct revoked_serial_tree *rt, u_int64_t lo, u_int64_t hi)
{
struct revoked_serial rs, *ers, *crs, *irs;
KRL_DBG(("insert %llu:%llu", lo, hi));
memset(&rs, 0, sizeof(rs));
rs.lo = lo;
rs.hi = hi;
ers = RB_NFIND(revoked_serial_tree, rt, &rs);
if (ers == NULL || serial_cmp(ers, &rs) != 0) {
/* No entry matches. Just insert */
if ((irs = malloc(sizeof(rs))) == NULL)
return SSH_ERR_ALLOC_FAIL;
memcpy(irs, &rs, sizeof(*irs));
ers = RB_INSERT(revoked_serial_tree, rt, irs);
if (ers != NULL) {
KRL_DBG(("bad: ers != NULL"));
/* Shouldn't happen */
free(irs);
return SSH_ERR_INTERNAL_ERROR;
}
ers = irs;
} else {
KRL_DBG(("overlap found %llu:%llu", ers->lo, ers->hi));
/*
* The inserted entry overlaps an existing one. Grow the
* existing entry.
*/
if (ers->lo > lo)
ers->lo = lo;
if (ers->hi < hi)
ers->hi = hi;
}
/*
* The inserted or revised range might overlap or abut adjacent ones;
* coalesce as necessary.
*/
/* Check predecessors */
while ((crs = RB_PREV(revoked_serial_tree, rt, ers)) != NULL) {
KRL_DBG(("pred %llu:%llu", crs->lo, crs->hi));
if (ers->lo != 0 && crs->hi < ers->lo - 1)
break;
/* This entry overlaps. */
if (crs->lo < ers->lo) {
ers->lo = crs->lo;
KRL_DBG(("pred extend %llu:%llu", ers->lo, ers->hi));
}
RB_REMOVE(revoked_serial_tree, rt, crs);
free(crs);
}
/* Check successors */
while ((crs = RB_NEXT(revoked_serial_tree, rt, ers)) != NULL) {
KRL_DBG(("succ %llu:%llu", crs->lo, crs->hi));
if (ers->hi != (u_int64_t)-1 && crs->lo > ers->hi + 1)
break;
/* This entry overlaps. */
if (crs->hi > ers->hi) {
ers->hi = crs->hi;
KRL_DBG(("succ extend %llu:%llu", ers->lo, ers->hi));
}
RB_REMOVE(revoked_serial_tree, rt, crs);
free(crs);
}
KRL_DBG(("done, final %llu:%llu", ers->lo, ers->hi));
return 0;
}
int
ssh_krl_revoke_cert_by_serial(struct ssh_krl *krl, const struct sshkey *ca_key,
u_int64_t serial)
{
return ssh_krl_revoke_cert_by_serial_range(krl, ca_key, serial, serial);
}
int
ssh_krl_revoke_cert_by_serial_range(struct ssh_krl *krl,
const struct sshkey *ca_key, u_int64_t lo, u_int64_t hi)
{
struct revoked_certs *rc;
int r;
if (lo > hi || lo == 0)
return SSH_ERR_INVALID_ARGUMENT;
if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
return r;
return insert_serial_range(&rc->revoked_serials, lo, hi);
}
int
ssh_krl_revoke_cert_by_key_id(struct ssh_krl *krl, const struct sshkey *ca_key,
const char *key_id)
{
struct revoked_key_id *rki, *erki;
struct revoked_certs *rc;
int r;
if ((r = revoked_certs_for_ca_key(krl, ca_key, &rc, 1)) != 0)
return r;
KRL_DBG(("revoke %s", key_id));
if ((rki = calloc(1, sizeof(*rki))) == NULL ||
(rki->key_id = strdup(key_id)) == NULL) {
free(rki);
return SSH_ERR_ALLOC_FAIL;
}
erki = RB_INSERT(revoked_key_id_tree, &rc->revoked_key_ids, rki);
if (erki != NULL) {
free(rki->key_id);
free(rki);
}
return 0;
}
/* Convert "key" to a public key blob without any certificate information */
static int
plain_key_blob(const struct sshkey *key, u_char **blob, size_t *blen)
{
struct sshkey *kcopy;
int r;
if ((r = sshkey_from_private(key, &kcopy)) != 0)
return r;
if (sshkey_is_cert(kcopy)) {
if ((r = sshkey_drop_cert(kcopy)) != 0) {
sshkey_free(kcopy);
return r;
}
}
r = sshkey_to_blob(kcopy, blob, blen);
sshkey_free(kcopy);
return r;
}
/* Revoke a key blob. Ownership of blob is transferred to the tree */
static int
revoke_blob(struct revoked_blob_tree *rbt, u_char *blob, size_t len)
{
struct revoked_blob *rb, *erb;
if ((rb = calloc(1, sizeof(*rb))) == NULL)
return SSH_ERR_ALLOC_FAIL;
rb->blob = blob;
rb->len = len;
erb = RB_INSERT(revoked_blob_tree, rbt, rb);
if (erb != NULL) {
free(rb->blob);
free(rb);
}
return 0;
}
int
ssh_krl_revoke_key_explicit(struct ssh_krl *krl, const struct sshkey *key)
{
u_char *blob;
size_t len;
int r;
debug3_f("revoke type %s", sshkey_type(key));
if ((r = plain_key_blob(key, &blob, &len)) != 0)
return r;
return revoke_blob(&krl->revoked_keys, blob, len);
}
static int
revoke_by_hash(struct revoked_blob_tree *target, const u_char *p, size_t len)
{
u_char *blob;
int r;
/* need to copy hash, as revoke_blob steals ownership */
if ((blob = malloc(len)) == NULL)
return SSH_ERR_SYSTEM_ERROR;
memcpy(blob, p, len);
if ((r = revoke_blob(target, blob, len)) != 0) {
free(blob);
return r;
}
return 0;
}
int
ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const u_char *p, size_t len)
{
debug3_f("revoke by sha1");
if (len != 20)
return SSH_ERR_INVALID_FORMAT;
return revoke_by_hash(&krl->revoked_sha1s, p, len);
}
int
ssh_krl_revoke_key_sha256(struct ssh_krl *krl, const u_char *p, size_t len)
{
debug3_f("revoke by sha256");
if (len != 32)
return SSH_ERR_INVALID_FORMAT;
return revoke_by_hash(&krl->revoked_sha256s, p, len);
}
int
ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key)
{
/* XXX replace with SHA256? */
if (!sshkey_is_cert(key))
return ssh_krl_revoke_key_explicit(krl, key);
if (key->cert->serial == 0) {
return ssh_krl_revoke_cert_by_key_id(krl,
key->cert->signature_key,
key->cert->key_id);
} else {
return ssh_krl_revoke_cert_by_serial(krl,
key->cert->signature_key,
key->cert->serial);
}
}
/*
* Select the most compact section type to emit next in a KRL based on
* the current section type, the run length of contiguous revoked serial
* numbers and the gaps from the last and to the next revoked serial.
* Applies a mostly-accurate bit cost model to select the section type
* that will minimise the size of the resultant KRL.
*/
static int
choose_next_state(int current_state, u_int64_t contig, int final,
u_int64_t last_gap, u_int64_t next_gap, int *force_new_section)
{
int new_state;
u_int64_t cost, cost_list, cost_range, cost_bitmap, cost_bitmap_restart;
/*
* Avoid unsigned overflows.
* The limits are high enough to avoid confusing the calculations.
*/
contig = MINIMUM(contig, 1ULL<<31);
last_gap = MINIMUM(last_gap, 1ULL<<31);
next_gap = MINIMUM(next_gap, 1ULL<<31);
/*
* Calculate the cost to switch from the current state to candidates.
* NB. range sections only ever contain a single range, so their
* switching cost is independent of the current_state.
*/
cost_list = cost_bitmap = cost_bitmap_restart = 0;
cost_range = 8;
switch (current_state) {
case KRL_SECTION_CERT_SERIAL_LIST:
cost_bitmap_restart = cost_bitmap = 8 + 64;
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
cost_list = 8;
cost_bitmap_restart = 8 + 64;
break;
case KRL_SECTION_CERT_SERIAL_RANGE:
case 0:
cost_bitmap_restart = cost_bitmap = 8 + 64;
cost_list = 8;
}
/* Estimate base cost in bits of each section type */
cost_list += 64 * contig + (final ? 0 : 8+64);
cost_range += (2 * 64) + (final ? 0 : 8+64);
cost_bitmap += last_gap + contig + (final ? 0 : MINIMUM(next_gap, 8+64));
cost_bitmap_restart += contig + (final ? 0 : MINIMUM(next_gap, 8+64));
/* Convert to byte costs for actual comparison */
cost_list = (cost_list + 7) / 8;
cost_bitmap = (cost_bitmap + 7) / 8;
cost_bitmap_restart = (cost_bitmap_restart + 7) / 8;
cost_range = (cost_range + 7) / 8;
/* Now pick the best choice */
*force_new_section = 0;
new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
cost = cost_bitmap;
if (cost_range < cost) {
new_state = KRL_SECTION_CERT_SERIAL_RANGE;
cost = cost_range;
}
if (cost_list < cost) {
new_state = KRL_SECTION_CERT_SERIAL_LIST;
cost = cost_list;
}
if (cost_bitmap_restart < cost) {
new_state = KRL_SECTION_CERT_SERIAL_BITMAP;
*force_new_section = 1;
cost = cost_bitmap_restart;
}
KRL_DBG(("contig %llu last_gap %llu next_gap %llu final %d, costs:"
"list %llu range %llu bitmap %llu new bitmap %llu, "
"selected 0x%02x%s", (long long unsigned)contig,
(long long unsigned)last_gap, (long long unsigned)next_gap, final,
(long long unsigned)cost_list, (long long unsigned)cost_range,
(long long unsigned)cost_bitmap,
(long long unsigned)cost_bitmap_restart, new_state,
*force_new_section ? " restart" : ""));
return new_state;
}
static int
put_bitmap(struct sshbuf *buf, struct bitmap *bitmap)
{
size_t len;
u_char *blob;
int r;
len = bitmap_nbytes(bitmap);
if ((blob = malloc(len)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if (bitmap_to_string(bitmap, blob, len) != 0) {
free(blob);
return SSH_ERR_INTERNAL_ERROR;
}
r = sshbuf_put_bignum2_bytes(buf, blob, len);
free(blob);
return r;
}
/* Generate a KRL_SECTION_CERTIFICATES KRL section */
static int
revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
{
int final, force_new_sect, r = SSH_ERR_INTERNAL_ERROR;
u_int64_t i, contig, gap, last = 0, bitmap_start = 0;
struct revoked_serial *rs, *nrs;
struct revoked_key_id *rki;
int next_state, state = 0;
struct sshbuf *sect;
struct bitmap *bitmap = NULL;
if ((sect = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
/* Store the header: optional CA scope key, reserved */
if (rc->ca_key == NULL) {
if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
goto out;
} else {
if ((r = sshkey_puts(rc->ca_key, buf)) != 0)
goto out;
}
if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
goto out;
/* Store the revoked serials. */
for (rs = RB_MIN(revoked_serial_tree, &rc->revoked_serials);
rs != NULL;
rs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs)) {
KRL_DBG(("serial %llu:%llu state 0x%02x",
(long long unsigned)rs->lo, (long long unsigned)rs->hi,
state));
/* Check contiguous length and gap to next section (if any) */
nrs = RB_NEXT(revoked_serial_tree, &rc->revoked_serials, rs);
final = nrs == NULL;
gap = nrs == NULL ? 0 : nrs->lo - rs->hi;
contig = 1 + (rs->hi - rs->lo);
/* Choose next state based on these */
next_state = choose_next_state(state, contig, final,
state == 0 ? 0 : rs->lo - last, gap, &force_new_sect);
/*
* If the current section is a range section or has a different
* type to the next section, then finish it off now.
*/
if (state != 0 && (force_new_sect || next_state != state ||
state == KRL_SECTION_CERT_SERIAL_RANGE)) {
KRL_DBG(("finish state 0x%02x", state));
switch (state) {
case KRL_SECTION_CERT_SERIAL_LIST:
case KRL_SECTION_CERT_SERIAL_RANGE:
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if ((r = put_bitmap(sect, bitmap)) != 0)
goto out;
bitmap_free(bitmap);
bitmap = NULL;
break;
}
if ((r = sshbuf_put_u8(buf, state)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
sshbuf_reset(sect);
}
/* If we are starting a new section then prepare it now */
if (next_state != state || force_new_sect) {
KRL_DBG(("start state 0x%02x",
next_state));
state = next_state;
sshbuf_reset(sect);
switch (state) {
case KRL_SECTION_CERT_SERIAL_LIST:
case KRL_SECTION_CERT_SERIAL_RANGE:
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if ((bitmap = bitmap_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
bitmap_start = rs->lo;
if ((r = sshbuf_put_u64(sect,
bitmap_start)) != 0)
goto out;
break;
}
}
/* Perform section-specific processing */
switch (state) {
case KRL_SECTION_CERT_SERIAL_LIST:
for (i = 0; i < contig; i++) {
if ((r = sshbuf_put_u64(sect, rs->lo + i)) != 0)
goto out;
}
break;
case KRL_SECTION_CERT_SERIAL_RANGE:
if ((r = sshbuf_put_u64(sect, rs->lo)) != 0 ||
(r = sshbuf_put_u64(sect, rs->hi)) != 0)
goto out;
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if (rs->lo - bitmap_start > INT_MAX) {
error_f("insane bitmap gap");
goto out;
}
for (i = 0; i < contig; i++) {
if (bitmap_set_bit(bitmap,
rs->lo + i - bitmap_start) != 0) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
}
break;
}
last = rs->hi;
}
/* Flush the remaining section, if any */
if (state != 0) {
KRL_DBG(("serial final flush for state 0x%02x", state));
switch (state) {
case KRL_SECTION_CERT_SERIAL_LIST:
case KRL_SECTION_CERT_SERIAL_RANGE:
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if ((r = put_bitmap(sect, bitmap)) != 0)
goto out;
bitmap_free(bitmap);
bitmap = NULL;
break;
}
if ((r = sshbuf_put_u8(buf, state)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
KRL_DBG(("serial done "));
/* Now output a section for any revocations by key ID */
sshbuf_reset(sect);
RB_FOREACH(rki, revoked_key_id_tree, &rc->revoked_key_ids) {
KRL_DBG(("key ID %s", rki->key_id));
if ((r = sshbuf_put_cstring(sect, rki->key_id)) != 0)
goto out;
}
if (sshbuf_len(sect) != 0) {
if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERT_KEY_ID)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
r = 0;
out:
bitmap_free(bitmap);
sshbuf_free(sect);
return r;
}
int
ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf,
struct sshkey **sign_keys, u_int nsign_keys)
{
int r = SSH_ERR_INTERNAL_ERROR;
struct revoked_certs *rc;
struct revoked_blob *rb;
struct sshbuf *sect;
u_char *sblob = NULL;
size_t slen, i;
if (krl->generated_date == 0)
krl->generated_date = time(NULL);
if ((sect = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
/* Store the header */
if ((r = sshbuf_put(buf, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0 ||
(r = sshbuf_put_u32(buf, KRL_FORMAT_VERSION)) != 0 ||
(r = sshbuf_put_u64(buf, krl->krl_version)) != 0 ||
(r = sshbuf_put_u64(buf, krl->generated_date)) != 0 ||
(r = sshbuf_put_u64(buf, krl->flags)) != 0 ||
(r = sshbuf_put_string(buf, NULL, 0)) != 0 ||
(r = sshbuf_put_cstring(buf, krl->comment)) != 0)
goto out;
/* Store sections for revoked certificates */
TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
sshbuf_reset(sect);
if ((r = revoked_certs_generate(rc, sect)) != 0)
goto out;
if ((r = sshbuf_put_u8(buf, KRL_SECTION_CERTIFICATES)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
/* Finally, output sections for revocations by public key/hash */
sshbuf_reset(sect);
RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_keys) {
KRL_DBG(("key len %zu ", rb->len));
if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
goto out;
}
if (sshbuf_len(sect) != 0) {
if ((r = sshbuf_put_u8(buf, KRL_SECTION_EXPLICIT_KEY)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
sshbuf_reset(sect);
RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha1s) {
KRL_DBG(("hash len %zu ", rb->len));
if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
goto out;
}
if (sshbuf_len(sect) != 0) {
if ((r = sshbuf_put_u8(buf,
KRL_SECTION_FINGERPRINT_SHA1)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
sshbuf_reset(sect);
RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) {
KRL_DBG(("hash len %zu ", rb->len));
if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
goto out;
}
if (sshbuf_len(sect) != 0) {
if ((r = sshbuf_put_u8(buf,
KRL_SECTION_FINGERPRINT_SHA256)) != 0 ||
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
for (i = 0; i < nsign_keys; i++) {
KRL_DBG(("sig key %s", sshkey_ssh_name(sign_keys[i])));
if ((r = sshbuf_put_u8(buf, KRL_SECTION_SIGNATURE)) != 0 ||
(r = sshkey_puts(sign_keys[i], buf)) != 0)
goto out;
/* XXX support sk-* keys */
if ((r = sshkey_sign(sign_keys[i], &sblob, &slen,
sshbuf_ptr(buf), sshbuf_len(buf), NULL, NULL,
NULL, 0)) != 0)
goto out;
KRL_DBG(("signature sig len %zu", slen));
if ((r = sshbuf_put_string(buf, sblob, slen)) != 0)
goto out;
}
r = 0;
out:
free(sblob);
sshbuf_free(sect);
return r;
}
static void
format_timestamp(u_int64_t timestamp, char *ts, size_t nts)
{
time_t t;
struct tm *tm;
t = timestamp;
tm = localtime(&t);
if (tm == NULL)
strlcpy(ts, "<INVALID>", nts);
else {
*ts = '\0';
strftime(ts, nts, "%Y%m%dT%H%M%S", tm);
}
}
static int
cert_extension_subsection(struct sshbuf *subsect, struct ssh_krl *krl)
{
int r = SSH_ERR_INTERNAL_ERROR;
u_char critical = 1;
struct sshbuf *value = NULL;
char *name = NULL;
if ((r = sshbuf_get_cstring(subsect, &name, NULL)) != 0 ||
(r = sshbuf_get_u8(subsect, &critical)) != 0 ||
(r = sshbuf_froms(subsect, &value)) != 0) {
debug_fr(r, "parse");
error("KRL has invalid certificate extension subsection");
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (sshbuf_len(subsect) != 0) {
error("KRL has invalid certificate extension subsection: "
"trailing data");
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
debug_f("cert extension %s critical %u len %zu",
name, critical, sshbuf_len(value));
/* no extensions are currently supported */
if (critical) {
error("KRL contains unsupported critical certificate "
"subsection \"%s\"", name);
r = SSH_ERR_FEATURE_UNSUPPORTED;
goto out;
}
/* success */
r = 0;
out:
free(name);
sshbuf_free(value);
return r;
}
static int
parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
{
int r = SSH_ERR_INTERNAL_ERROR;
u_char type;
const u_char *blob;
size_t blen, nbits;
struct sshbuf *subsect = NULL;
u_int64_t serial, serial_lo, serial_hi;
struct bitmap *bitmap = NULL;
char *key_id = NULL;
struct sshkey *ca_key = NULL;
if ((subsect = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
/* Header: key, reserved */
if ((r = sshbuf_get_string_direct(buf, &blob, &blen)) != 0 ||
(r = sshbuf_skip_string(buf)) != 0)
goto out;
if (blen != 0 && (r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
goto out;
while (sshbuf_len(buf) > 0) {
sshbuf_free(subsect);
subsect = NULL;
if ((r = sshbuf_get_u8(buf, &type)) != 0 ||
(r = sshbuf_froms(buf, &subsect)) != 0)
goto out;
KRL_DBG(("subsection type 0x%02x", type));
/* sshbuf_dump(subsect, stderr); */
switch (type) {
case KRL_SECTION_CERT_SERIAL_LIST:
while (sshbuf_len(subsect) > 0) {
if ((r = sshbuf_get_u64(subsect, &serial)) != 0)
goto out;
if ((r = ssh_krl_revoke_cert_by_serial(krl,
ca_key, serial)) != 0)
goto out;
}
break;
case KRL_SECTION_CERT_SERIAL_RANGE:
if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
(r = sshbuf_get_u64(subsect, &serial_hi)) != 0)
goto out;
if ((r = ssh_krl_revoke_cert_by_serial_range(krl,
ca_key, serial_lo, serial_hi)) != 0)
goto out;
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if ((bitmap = bitmap_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
(r = sshbuf_get_bignum2_bytes_direct(subsect,
&blob, &blen)) != 0)
goto out;
if (bitmap_from_string(bitmap, blob, blen) != 0) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
nbits = bitmap_nbits(bitmap);
for (serial = 0; serial < (u_int64_t)nbits; serial++) {
if (serial > 0 && serial_lo + serial == 0) {
error_f("bitmap wraps u64");
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (!bitmap_test_bit(bitmap, serial))
continue;
if ((r = ssh_krl_revoke_cert_by_serial(krl,
ca_key, serial_lo + serial)) != 0)
goto out;
}
bitmap_free(bitmap);
bitmap = NULL;
break;
case KRL_SECTION_CERT_KEY_ID:
while (sshbuf_len(subsect) > 0) {
if ((r = sshbuf_get_cstring(subsect,
&key_id, NULL)) != 0)
goto out;
if ((r = ssh_krl_revoke_cert_by_key_id(krl,
ca_key, key_id)) != 0)
goto out;
free(key_id);
key_id = NULL;
}
break;
case KRL_SECTION_CERT_EXTENSION:
if ((r = cert_extension_subsection(subsect, krl)) != 0)
goto out;
break;
default:
error("Unsupported KRL certificate section %u", type);
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (sshbuf_len(subsect) > 0) {
error("KRL certificate section contains unparsed data");
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
}
r = 0;
out:
if (bitmap != NULL)
bitmap_free(bitmap);
free(key_id);
sshkey_free(ca_key);
sshbuf_free(subsect);
return r;
}
static int
blob_section(struct sshbuf *sect, struct revoked_blob_tree *target_tree,