-
Notifications
You must be signed in to change notification settings - Fork 27
/
pivy-agent.c
3450 lines (3112 loc) · 83.3 KB
/
pivy-agent.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
/*
* Newly written portions Copyright 2018 Joyent, Inc.
* Copyright 2023 The University of Queensland
* Author: Alex Wilson <alex.wilson@joyent.com>, <alex@uq.edu.au>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Partially derived from the original OpenSSH agent.c.
*
* Original copyright and license from OpenSSH:
*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* The authentication agent program.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include "debug.h"
#include <openssl/err.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/evp.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <pwd.h>
#include "utils.h"
#include "openssh/config.h"
#include "openssh/ssh2.h"
#include "openssh/sshbuf.h"
#include "openssh/sshkey.h"
#include "openssh/authfd.h"
#include "openssh/ssherr.h"
#include "bunyan.h"
#include "tlv.h"
#include "piv.h"
#include "errf.h"
#include "slot-spec.h"
#if defined(__APPLE__)
#include <PCSC/wintypes.h>
#include <PCSC/winscard.h>
#else
#include <wintypes.h>
#include <winscard.h>
#endif
#if defined(__sun)
#include <ucred.h>
#include <procfs.h>
#include <zone.h>
#endif
#if defined(__OpenBSD__)
#include <sys/sysctl.h>
#endif
#if defined(__APPLE__)
#include <sys/proc_info.h>
#include <sys/ucred.h>
#include <libproc.h>
#endif
#include "openssh/digest.h"
#include "openssh/cipher.h"
#include "openssh/ssherr.h"
#define MINIMUM(a,b) (((a) < (b)) ? (a) : (b))
/*
* Name of the environment variable containing the process ID of the
* authentication agent.
*/
#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID"
/*
* Name of the environment variable containing the pathname of the
* authentication socket.
*/
#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK"
/* Listen backlog for sshd, ssh-agent and forwarding sockets */
#define SSH_LISTEN_BACKLOG 128
#define MAX_PIN_LEN 16
#define parserrf(sshfunc, rc) \
errf("ParseError", ssherrf(sshfunc, rc), \
"failed to parse request in %s", __func__)
#define nopinerrf(cause) \
errf("NoPINError", cause, "no PIN has been supplied to the agent " \
"(try ssh-add -X)")
#define flagserrf(val) \
errf("FlagsError", NULL, "unsupported flags value: %x", val)
#define pcscerrf(call, rv) \
errf("PCSCError", NULL, call " failed: %d (%s)", \
rv, pcsc_stringify_error(rv))
typedef enum confirm_mode {
C_NEVER,
C_CONNECTION,
C_FORWARDED
} confirm_mode_t;
static struct piv_token *ks = NULL;
static struct piv_token *selk = NULL;
static boolean_t txnopen = B_FALSE;
static uint64_t txntimeout = 0;
static struct piv_ctx *ctx;
static uint64_t last_update;
static uint8_t *guid = NULL;
static size_t guid_len = 0;
static boolean_t sign_9d = B_FALSE;
static confirm_mode_t confirm_mode = C_NEVER;
static struct slotspec *slot_ena;
typedef struct uid_entry {
struct uid_entry *ue_next;
uid_t ue_uid;
} uid_entry_t;
#define UID_MOD 32
static uid_entry_t *uid_allow[UID_MOD] = { NULL };
static boolean_t allow_any_uid = B_FALSE;
#if defined(__sun)
typedef struct zone_entry {
struct zone_entry *ze_next;
zoneid_t ze_zid;
} zone_entry_t;
#define ZID_MOD 32
static zone_entry_t *zone_allow[ZID_MOD] = { NULL };
static boolean_t allow_any_zoneid = B_FALSE;
#endif
static char *pinmem = NULL;
static char *pin = NULL;
static size_t pin_len = 0;
static struct sshkey *cak = NULL;
static struct bunyan_frame *msg_log_frame;
/* Maximum accepted message length */
#define AGENT_MAX_LEN (256*1024)
typedef enum sock_type {
AUTH_UNUSED,
AUTH_SOCKET,
AUTH_CONNECTION
} sock_type_t;
typedef enum authz {
AUTHZ_NOT_YET = 0,
AUTHZ_DENIED,
AUTHZ_ALLOWED
} authz_t;
typedef enum sessbind {
SESSBIND_NONE = 0,
SESSBIND_AUTH,
SESSBIND_FWD
} sessbind_t;
typedef struct pid_entry {
boolean_t pe_valid;
uint64_t pe_time;
pid_t pe_pid;
uint64_t pe_start_time;
uint pe_conn_count;
uint64_t pe_last_auth;
} pid_entry_t;
typedef struct socket_entry {
int se_fd;
sock_type_t se_type;
pid_t se_pid;
uid_t se_uid;
gid_t se_gid;
char *se_exepath;
char *se_exeargs;
authz_t se_authz;
struct sshbuf *se_input;
struct sshbuf *se_output;
struct sshbuf *se_request;
pid_entry_t *se_pid_ent;
uint se_pid_idx;
sessbind_t se_sbind;
#if defined(__sun)
zoneid_t se_zid;
char se_zname[128];
#endif
} socket_entry_t;
u_int sockets_alloc = 0;
socket_entry_t *sockets = NULL;
pid_entry_t *pids = NULL;
uint pids_alloc = 0;
int max_fd = 0;
const time_t card_probe_interval_nopin = 120;
const time_t card_probe_interval_pin = 30;
const uint card_probe_limit = 3;
const uint64_t pid_auth_cache_time = 15000;
time_t card_probe_interval = 120; /* card_probe_interval_nopin */
uint card_probe_fails = 0;
uint64_t card_probe_next = 0;
/* pid of shell == parent of agent */
pid_t parent_pid = -1;
time_t parent_alive_interval = 0;
/* pid of process for which cleanup_socket is applicable */
pid_t cleanup_pid = 0;
/* pathname and directory for AUTH_SOCKET */
char socket_name[PATH_MAX + 20];
char socket_dir[PATH_MAX];
/* locking */
#define LOCK_SIZE 32
#define LOCK_SALT_SIZE 16
#define LOCK_ROUNDS 1
int locked = 0;
u_char lock_pwhash[LOCK_SIZE];
u_char lock_salt[LOCK_SALT_SIZE];
extern char *__progname;
/* Default lifetime in seconds (0 == forever) */
//static long lifetime = 0;
static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
extern void bunyan_timestamp(char *, size_t);
static int ssh_dbglevel = BNY_WARN;
static void
sdebug(const char *fmt, ...)
{
va_list args;
char ts[128];
if (ssh_dbglevel > BNY_TRACE)
return;
bunyan_timestamp(ts, sizeof (ts));
va_start(args, fmt);
fprintf(stderr, "[%s] TRACE: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
}
static void
error(const char *fmt, ...)
{
va_list args;
char ts[128];
if (ssh_dbglevel > BNY_ERROR)
return;
bunyan_timestamp(ts, sizeof (ts));
va_start(args, fmt);
fprintf(stderr, "[%s] ERROR: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
}
static void
fatal(const char *fmt, ...)
{
va_list args;
char ts[128];
va_start(args, fmt);
bunyan_timestamp(ts, sizeof (ts));
fprintf(stderr, "[%s] FATAL: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
exit(1);
}
static uint64_t
monotime(void)
{
struct timeval tv;
uint64_t msec;
gettimeofday(&tv, NULL);
msec = tv.tv_sec * 1000;
msec += tv.tv_usec / 1000;
return (msec);
}
static inline boolean_t
is_slot_enabled(struct piv_slot *slot)
{
return (slotspec_test(slot_ena, piv_slot_id(slot)));
}
static void
add_uid(uid_t uid)
{
uid_entry_t *ue;
uint slot = uid % UID_MOD;
ue = calloc(1, sizeof (uid_entry_t));
ue->ue_uid = uid;
ue->ue_next = uid_allow[slot];
uid_allow[slot] = ue;
}
static int
check_uid(uid_t uid)
{
uid_entry_t *ue;
uint slot = uid % UID_MOD;
for (ue = uid_allow[slot]; ue != NULL; ue = ue->ue_next) {
if (ue->ue_uid == uid)
return (1);
}
return (0);
}
#if defined(__sun)
static void
add_zid(zoneid_t zid)
{
zone_entry_t *ze;
uint slot = zid % ZID_MOD;
ze = calloc(1, sizeof (zone_entry_t));
ze->ze_zid = zid;
ze->ze_next = zone_allow[slot];
zone_allow[slot] = ze;
}
static int
check_zid(zoneid_t zid)
{
zone_entry_t *ze;
uint slot = zid % ZID_MOD;
for (ze = zone_allow[slot]; ze != NULL; ze = ze->ze_next) {
if (ze->ze_zid == zid)
return (1);
}
return (0);
}
#endif
static void
agent_piv_close(boolean_t force)
{
uint64_t now = monotime();
VERIFY(txnopen);
if (force || now >= txntimeout) {
bunyan_log(BNY_TRACE, "closing txn",
"now", BNY_UINT64, now,
"txntimeout", BNY_UINT64, txntimeout, NULL);
piv_txn_end(selk);
txnopen = B_FALSE;
}
}
static char *
piv_token_shortid(struct piv_token *pk)
{
char *guid;
if (piv_token_has_chuid(pk)) {
guid = strdup(piv_token_guid_hex(pk));
} else {
guid = strdup("0000000000");
}
guid[8] = '\0';
return (guid);
}
static const char *
pin_type_to_name(enum piv_pin type)
{
switch (type) {
case PIV_PIN:
return ("PIV PIN");
case PIV_GLOBAL_PIN:
return ("Global PIN");
case PIV_PUK:
return ("PUK");
default:
VERIFY(0);
return (NULL);
}
}
static errf_t *
valid_pin(const char *pin)
{
int i;
if (strlen(pin) < 4 || strlen(pin) > 8) {
return (errf("InvalidPIN", NULL, "PIN must be 4-8 characters "
"(was given %d)", strlen(pin)));
}
for (i = 0; pin[i] != 0; ++i) {
if (!(pin[i] >= '0' && pin[i] <= '9') &&
!(pin[i] >= 'a' && pin[i] <= 'z') &&
!(pin[i] >= 'A' && pin[i] <= 'Z')) {
return (errf("InvalidPIN", NULL, "PIN contains "
"invalid characters: '%c'", pin[i]));
}
}
return (NULL);
}
static void
set_probe_interval(boolean_t pin_loaded)
{
uint64_t now;
now = monotime();
if (pin_loaded)
card_probe_interval = card_probe_interval_pin;
else
card_probe_interval = card_probe_interval_nopin;
now += card_probe_interval * 1000;
if (now <= card_probe_next)
card_probe_next = now;
}
static void
extend_probe_deadline(void)
{
uint64_t now;
now = monotime();
now += card_probe_interval * 1000;
card_probe_next = now;
}
static void
drop_pin(void)
{
if (pin_len != 0) {
bunyan_log(BNY_INFO, "clearing PIN from memory", NULL);
explicit_bzero(pin, pin_len);
}
pin_len = 0;
set_probe_interval(B_FALSE);
}
static errf_t *
auth_cak(void)
{
struct piv_slot *slot;
errf_t *err;
slot = piv_get_slot(selk, PIV_SLOT_CARD_AUTH);
if (slot == NULL) {
err = errf("CAKAuthError", NULL, "No key was found in the "
"CARD_AUTH (CAK) slot");
return (err);
}
err = piv_auth_key(selk, slot, cak);
if (err) {
err = errf("CAKAuthError", err, "Key in CARD_AUTH slot (CAK) "
"does not match the configured CAK: this card may be "
"a fake!");
return (err);
}
return (NULL);
}
static errf_t *
agent_piv_open(void)
{
struct piv_slot *slot;
errf_t *err = NULL;
if (txnopen) {
txntimeout = monotime() + 2000;
return (NULL);
}
if (selk == NULL || (err = piv_txn_begin(selk))) {
errf_free(err);
selk = NULL;
if (ks != NULL)
piv_release(ks);
findagain:
err = piv_find(ctx, guid, guid_len, &ks);
if (err && errf_caused_by(err, "PCSCContextError")) {
ks = NULL;
bunyan_log(BNY_TRACE, "got context error, re-initing",
"error", BNY_ERF, err, NULL);
errf_free(err);
piv_close(ctx);
ctx = piv_open();
err = piv_establish_context(ctx, SCARD_SCOPE_SYSTEM);
if (err)
return (err);
goto findagain;
} else if (err) {
ks = NULL;
err = errf("EnumerationError", err, "Failed to "
"find specified PIV token on the system");
return (err);
}
selk = ks;
if (selk == NULL) {
err = errf("NotFoundError", NULL, "PIV card with "
"given GUID is not present on the system");
if (monotime() - last_update > 5000)
drop_pin();
return (err);
}
if ((err = piv_txn_begin(selk))) {
return (err);
}
if ((err = piv_select(selk))) {
piv_txn_end(selk);
return (err);
}
err = piv_read_all_certs(selk);
if (err && !errf_caused_by(err, "NotFoundError") &&
!errf_caused_by(err, "NotSupportedError")) {
piv_txn_end(selk);
return (err);
}
if (cak != NULL && (err = auth_cak())) {
piv_txn_end(selk);
drop_pin();
return (err);
}
last_update = monotime();
} else {
if ((err = piv_select(selk))) {
piv_txn_end(selk);
return (err);
}
}
if (cak == NULL) {
slot = piv_get_slot(selk, PIV_SLOT_CARD_AUTH);
if (slot != NULL)
VERIFY0(sshkey_demote(piv_slot_pubkey(slot), &cak));
}
bunyan_log(BNY_TRACE, "opened new txn", NULL);
txnopen = B_TRUE;
txntimeout = monotime() + 2000;
card_probe_fails = 0;
return (NULL);
}
static void
probe_card(void)
{
errf_t *err;
uint64_t now;
now = monotime();
card_probe_next = now + card_probe_interval * 1000;
if (card_probe_fails > card_probe_limit)
return;
bunyan_log(BNY_TRACE, "doing idle probe", NULL);
if ((err = agent_piv_open())) {
bunyan_log(BNY_TRACE, "error opening for idle probe",
"error", BNY_ERF, err, NULL);
errf_free(err);
/*
* Allow one failure due to connectivity issues before we
* drop the PIN (so that transient glitches aren't so
* inconvenient).
*/
if (card_probe_fails++ > 0)
drop_pin();
selk = NULL;
card_probe_next = now + card_probe_interval * 1000;
return;
}
if (cak != NULL && (err = auth_cak())) {
bunyan_log(BNY_WARN, "CAK authentication failed",
"error", BNY_ERF, err, NULL);
agent_piv_close(B_TRUE);
/* Always drop PIN on a CAK failure. */
drop_pin();
selk = NULL;
card_probe_fails++;
card_probe_next = now + card_probe_interval * 1000;
return;
}
agent_piv_close(B_FALSE);
card_probe_fails = 0;
}
static errf_t *
wrap_pin_error(errf_t *err, int retries)
{
if (errf_caused_by(err, "PermissionError")) {
if (retries == 0) {
err = errf("TokenLocked", err,
"PIV token is locked due to too many "
"invalid PIN code attempts");
} else {
err = errf("InvalidPIN", err,
"Invalid PIN code supplied (%d attempts "
"remaining)", retries);
drop_pin();
}
} else if (errf_caused_by(err, "MinRetriesError")) {
err = errf("TokenLocked", err,
"Refusing to use up the last PIN code attempt: "
"unlock the token with another tool to clear "
"the counter (e.g. pivy-tool with -f)");
drop_pin();
}
return (err);
}
static const char *askpass = NULL;
static const char *confirm = NULL;
static const char *notify = NULL;
static void
try_askpass(void)
{
int p[2], status;
pid_t kid, ret;
size_t len;
errf_t *err;
uint retries = 1;
char prompt[64], buf[1024];
char *guid = piv_token_shortid(selk);
enum piv_pin auth = piv_token_default_auth(selk);
snprintf(prompt, 64, "Enter %s for token %s",
pin_type_to_name(auth), guid);
if (askpass == NULL)
askpass = getenv("SSH_ASKPASS");
if (askpass == NULL)
return;
if (pipe(p) == -1)
return;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(p[0]);
if (dup2(p[1], STDOUT_FILENO) == -1)
exit(1);
execlp(askpass, askpass, prompt, (char *)NULL);
exit(1);
}
close(p[1]);
len = 0;
do {
ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (r == -1 && errno == EINTR)
continue;
if (r <= 0)
break;
len += r;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
explicit_bzero(buf, sizeof(buf));
bunyan_log(BNY_WARN, "executing askpass failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
buf[strcspn(buf, "\r\n")] = '\0';
if ((err = valid_pin(buf))) {
errf_free(err);
goto out;
}
if ((err = agent_piv_open())) {
errf_free(err);
goto out;
}
err = piv_verify_pin(selk, auth, buf, &retries, B_FALSE);
if (err != ERRF_OK) {
err = wrap_pin_error(err, retries);
bunyan_log(BNY_WARN, "failed to use PIN provided by askpass",
"error", BNY_ERF, err, NULL);
errf_free(err);
goto out;
}
extend_probe_deadline();
agent_piv_close(B_FALSE);
if (pin_len != 0)
explicit_bzero(pin, pin_len);
pin_len = strlen(buf);
bcopy(buf, pin, pin_len);
bunyan_log(BNY_INFO, "storing PIN in memory", NULL);
set_probe_interval(B_TRUE);
out:
explicit_bzero(buf, sizeof(buf));
}
static void
send_touch_notify(socket_entry_t *e, enum piv_slotid slotid)
{
int status;
pid_t kid, ret;
char msg[1024];
char title[256];
char *guid;
if (notify == NULL)
notify = getenv("SSH_NOTIFY_SEND");
if (notify == NULL)
return;
guid = piv_token_shortid(selk);
snprintf(title, sizeof (title),
"pivy-agent for token %s", guid);
snprintf(msg, sizeof (msg),
"Touch confirmation may be required to use key in slot %02X",
slotid);
free(guid);
guid = NULL;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(STDOUT_FILENO);
close(STDIN_FILENO);
execlp(notify, notify, title, msg, (char *)NULL);
exit(128);
}
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) ||
(WEXITSTATUS(status) != 0 && WEXITSTATUS(status) != 1)) {
bunyan_log(BNY_WARN, "executing notify failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
}
static void
try_confirm_client(socket_entry_t *e, enum piv_slotid slotid)
{
int status;
pid_t kid, ret;
boolean_t add_zenity_args = B_FALSE;
boolean_t add_notify_send_args = B_FALSE;
char prompt[1024], buf[64];
size_t len;
char *guid;
int p[2];
if (confirm_mode == C_NEVER) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
if (confirm_mode == C_FORWARDED) {
const char *ssh = NULL;
const size_t len = strlen(e->se_exepath);
const uint64_t now = monotime();
const int64_t delta = now - e->se_pid_ent->pe_last_auth;
/*
* If we've seen a session-bind for auth, this isn't a
* forwarded connection.
*/
if (e->se_sbind == SESSBIND_AUTH) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
/*
* If we haven't seen a session-bind at all, sniff whether this
* is an "ssh" process connected to us. If this is the very
* first connection that "ssh" process has made, assume it's
* the auth socket.
*/
if (e->se_sbind == SESSBIND_NONE) {
if (len >= 4)
ssh = &e->se_exepath[len - 4];
if (ssh != NULL && strcmp(ssh, "/ssh") != 0)
ssh = NULL;
if (len == 3 && strcmp(e->se_exepath, "ssh") == 0)
ssh = e->se_exepath;
if (e->se_pid_idx == 0 || ssh == NULL) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
}
/*
* Otherwise, check if the user has authorised this PID
* recently -- if they have, this connection is ok (and we
* should renew the PID's authorisation).
*/
if (e->se_pid_ent->pe_pid != 0 &&
pid_auth_cache_time > 0 &&
delta < pid_auth_cache_time) {
e->se_pid_ent->pe_last_auth = now;
e->se_authz = AUTHZ_ALLOWED;
return;
}
}
/* Otherwise we're going to try to obtain user consent. */
if (askpass == NULL)
askpass = getenv("SSH_ASKPASS");
if (confirm == NULL)
confirm = getenv("SSH_CONFIRM");
if (askpass == NULL && confirm == NULL) {
e->se_authz = AUTHZ_DENIED;
return;
}
if (confirm != NULL) {
char *tmp = strdup(confirm);
const char *execname = basename(tmp);
if (strcmp(execname, "zenity") == 0)
add_zenity_args = B_TRUE;
if (strcmp(execname, "notify-send") == 0)
add_notify_send_args = B_TRUE;
free(tmp);
}
guid = piv_token_shortid(selk);
snprintf(prompt, sizeof (prompt),
"%sA new client is trying to use PIV token %s\r\n\r\n"
"Client PID: %d\r\nClient executable: %s\r\nClient cmd: %s\r\n"
"Slot requested: %02x",
(add_zenity_args ? "--text=" : ""),
guid, (int)e->se_pid,
(e->se_exepath == NULL) ? "(unknown)" : e->se_exepath,
(e->se_exeargs == NULL) ? "(unknown)" : e->se_exeargs,
(uint)slotid);
free(guid);
guid = NULL;
if (pipe(p) == -1)
return;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(STDOUT_FILENO);
close(STDIN_FILENO);
close(p[0]);
if (dup2(p[1], STDOUT_FILENO) == -1)
exit(1);
if (confirm && add_zenity_args) {
execlp(confirm, confirm,
"--question", "--ok-label=Allow",
"--cancel-label=Block", "--width=300",
"--title=pivy-agent",
"--icon-name=application-certificate-symbolic",
prompt,
(char *)NULL);
} else if (confirm && add_notify_send_args) {
execlp(confirm, confirm,
"--app-name=pivy-agent",
"--icon=user-info",
"--urgency=critical",
"--expire-time=0",
"--wait",
"--action=allow=Allow",
"--action=deny=Deny",
"pivy-agent confirmation",
prompt,
(char *)NULL);
} else if (confirm) {
execlp(confirm, confirm, prompt, (char *)NULL);
} else {
setenv("SSH_ASKPASS_PROMPT", "confirm", 1);
execlp(askpass, askpass, prompt, (char *)NULL);
}
exit(128);
}
close(p[1]);
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) ||
(WEXITSTATUS(status) != 0 && WEXITSTATUS(status) != 1)) {
bunyan_log(BNY_WARN, "executing confirm failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
len = 0;
do {
ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (r == -1 && errno == EINTR)
continue;
if (r <= 0)
break;
len += r;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
if (WEXITSTATUS(status) == 0 && (!add_notify_send_args ||
strcmp(buf, "allow\n") == 0)) {
e->se_authz = AUTHZ_ALLOWED;
e->se_pid_ent->pe_last_auth = monotime();
} else {
e->se_authz = AUTHZ_DENIED;
}
}
static errf_t *
agent_piv_try_pin(boolean_t canskip)