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- Committer: Teddy Hogeborn
- Date: 2019-07-15 15:19:42 UTC
- Revision ID: teddy@recompile.se-20190715151942-f1itgz5mo2d2zczj
Client: Document requirement of libnl-route library
* INSTALL (Prerequisites/Libraries/Mandos Client): Add "libnl-route".
* Makefile (plugin-helpers/mandos-client-iprouteadddel): Write comment
explaining that the explicit target exists to add the
libnl-route library.
* INSTALL (Prerequisites/Libraries/Mandos Client): Add "libnl-route".
* Makefile (plugin-helpers/mandos-client-iprouteadddel): Write comment
explaining that the explicit target exists to add the
libnl-route library.
- files added:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- debian/tests
- debian/upstream
- network-hooks.d
- plugin-helpers
- plugins.d
- files removed:
- bad-ca.pem
- files modified:
- Makefile
added
removed
plugins.d/mandos-client.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Mandos-client - get and decrypt data from a Mandos server
4
*
5
* This program is partly derived from an example program for an Avahi
6
* service browser, downloaded from
7
* <http://avahi.org/browser/examples/core-browse-services.c>. This
8
* includes the following functions: "resolve_callback",
9
* "browse_callback", and parts of "main".
10
*
11
* Everything else is
12
* Copyright © 2008-2019 Teddy Hogeborn
13
* Copyright © 2008-2019 Björn Påhlsson
14
*
15
* This file is part of Mandos.
16
*
17
* Mandos is free software: you can redistribute it and/or modify it
18
* under the terms of the GNU General Public License as published by
19
* the Free Software Foundation, either version 3 of the License, or
20
* (at your option) any later version.
21
*
22
* Mandos is distributed in the hope that it will be useful, but
23
* WITHOUT ANY WARRANTY; without even the implied warranty of
24
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25
* General Public License for more details.
26
*
27
* You should have received a copy of the GNU General Public License
28
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
29
*
30
* Contact the authors at <mandos@recompile.se>.
31
*/
32
33
/* Needed by GPGME, specifically gpgme_data_seek() */
34
#ifndef _LARGEFILE_SOURCE
35
#define _LARGEFILE_SOURCE
36
#endif /* not _LARGEFILE_SOURCE */
37
#ifndef _FILE_OFFSET_BITS
38
#define _FILE_OFFSET_BITS 64
39
#endif /* not _FILE_OFFSET_BITS */
40
41
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
43
#include <stdio.h> /* fprintf(), stderr, fwrite(),
44
stdout, ferror() */
45
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
46
#include <stddef.h> /* NULL, size_t, ssize_t */
47
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
strtof(), abort() */
49
#include <stdbool.h> /* bool, false, true */
50
#include <string.h> /* strcmp(), strlen(), strerror(),
51
asprintf(), strncpy(), strsignal()
52
*/
53
#include <sys/ioctl.h> /* ioctl */
54
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
55
sockaddr_in6, PF_INET6,
56
SOCK_STREAM, uid_t, gid_t, open(),
57
opendir(), DIR */
58
#include <sys/stat.h> /* open(), S_ISREG */
59
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
60
inet_pton(), connect(),
61
getnameinfo() */
62
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
63
#include <dirent.h> /* opendir(), struct dirent, readdir()
64
*/
65
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
66
strtoimax() */
67
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
68
EAI_SYSTEM, ENETUNREACH,
69
EHOSTUNREACH, ECONNREFUSED, EPROTO,
70
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
71
ENOTEMPTY,
72
program_invocation_short_name */
73
#include <time.h> /* nanosleep(), time(), sleep() */
74
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
75
SIOCSIFFLAGS, if_indextoname(),
76
if_nametoindex(), IF_NAMESIZE */
77
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
78
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
79
*/
80
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
81
getuid(), getgid(), seteuid(),
82
setgid(), pause(), _exit(),
83
unlinkat() */
84
#include <arpa/inet.h> /* inet_pton(), htons() */
85
#include <iso646.h> /* not, or, and */
86
#include <argp.h> /* struct argp_option, error_t, struct
87
argp_state, struct argp,
88
argp_parse(), ARGP_KEY_ARG,
89
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
90
#include <signal.h> /* sigemptyset(), sigaddset(),
91
sigaction(), SIGTERM, sig_atomic_t,
92
raise() */
93
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
94
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
95
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
96
WEXITSTATUS(), WTERMSIG() */
97
#include <grp.h> /* setgroups() */
98
#include <argz.h> /* argz_add_sep(), argz_next(),
99
argz_delete(), argz_append(),
100
argz_stringify(), argz_add(),
101
argz_count() */
102
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
103
EAI_SYSTEM, gai_strerror() */
104
105
#ifdef __linux__
106
#include <sys/klog.h> /* klogctl() */
107
#endif /* __linux__ */
108
109
/* Avahi */
110
/* All Avahi types, constants and functions
111
Avahi*, avahi_*,
112
AVAHI_* */
113
#include <avahi-core/core.h>
114
#include <avahi-core/lookup.h>
115
#include <avahi-core/log.h>
116
#include <avahi-common/simple-watch.h>
117
#include <avahi-common/malloc.h>
118
#include <avahi-common/error.h>
119
120
/* GnuTLS */
121
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
122
functions:
123
gnutls_*
124
init_gnutls_session(),
125
GNUTLS_* */
126
#if GNUTLS_VERSION_NUMBER < 0x030600
127
#include <gnutls/openpgp.h>
128
/* gnutls_certificate_set_openpgp_key_file(),
129
GNUTLS_OPENPGP_FMT_BASE64 */
130
#elif GNUTLS_VERSION_NUMBER >= 0x030606
131
#include <gnutls/x509.h> /* gnutls_pkcs_encrypt_flags_t,
132
GNUTLS_PKCS_PLAIN,
133
GNUTLS_PKCS_NULL_PASSWORD */
134
#endif
135
136
/* GPGME */
137
#include <gpgme.h> /* All GPGME types, constants and
138
functions:
139
gpgme_*
140
GPGME_PROTOCOL_OpenPGP,
141
GPG_ERR_NO_* */
142
143
#define BUFFER_SIZE 256
144
145
#define PATHDIR "/conf/conf.d/mandos"
146
#define SECKEY "seckey.txt"
147
#define PUBKEY "pubkey.txt"
148
#define TLS_PRIVKEY "tls-privkey.pem"
149
#define TLS_PUBKEY "tls-pubkey.pem"
150
#define HOOKDIR "/lib/mandos/network-hooks.d"
151
152
bool debug = false;
153
static const char mandos_protocol_version[] = "1";
154
const char *argp_program_version = "mandos-client " VERSION;
155
const char *argp_program_bug_address = "<mandos@recompile.se>";
156
static const char sys_class_net[] = "/sys/class/net";
157
char *connect_to = NULL;
158
const char *hookdir = HOOKDIR;
159
int hookdir_fd = -1;
160
uid_t uid = 65534;
161
gid_t gid = 65534;
162
163
/* Doubly linked list that need to be circularly linked when used */
164
typedef struct server{
165
const char *ip;
166
in_port_t port;
167
AvahiIfIndex if_index;
168
int af;
169
struct timespec last_seen;
170
struct server *next;
171
struct server *prev;
172
} server;
173
174
/* Used for passing in values through the Avahi callback functions */
175
typedef struct {
176
AvahiServer *server;
177
gnutls_certificate_credentials_t cred;
178
unsigned int dh_bits;
179
gnutls_dh_params_t dh_params;
180
const char *priority;
181
gpgme_ctx_t ctx;
182
server *current_server;
183
char *interfaces;
184
size_t interfaces_size;
185
} mandos_context;
186
187
/* global so signal handler can reach it*/
188
AvahiSimplePoll *simple_poll;
189
190
sig_atomic_t quit_now = 0;
191
int signal_received = 0;
192
193
/* Function to use when printing errors */
194
void perror_plus(const char *print_text){
195
int e = errno;
196
fprintf(stderr, "Mandos plugin %s: ",
197
program_invocation_short_name);
198
errno = e;
199
perror(print_text);
200
}
201
202
__attribute__((format (gnu_printf, 2, 3), nonnull))
203
int fprintf_plus(FILE *stream, const char *format, ...){
204
va_list ap;
205
va_start (ap, format);
206
207
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
208
program_invocation_short_name));
209
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
210
}
211
212
/*
213
* Make additional room in "buffer" for at least BUFFER_SIZE more
214
* bytes. "buffer_capacity" is how much is currently allocated,
215
* "buffer_length" is how much is already used.
216
*/
217
__attribute__((nonnull, warn_unused_result))
218
size_t incbuffer(char **buffer, size_t buffer_length,
219
size_t buffer_capacity){
220
if(buffer_length + BUFFER_SIZE > buffer_capacity){
221
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
222
if(new_buf == NULL){
223
int old_errno = errno;
224
free(*buffer);
225
errno = old_errno;
226
*buffer = NULL;
227
return 0;
228
}
229
*buffer = new_buf;
230
buffer_capacity += BUFFER_SIZE;
231
}
232
return buffer_capacity;
233
}
234
235
/* Add server to set of servers to retry periodically */
236
__attribute__((nonnull, warn_unused_result))
237
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
238
int af, server **current_server){
239
int ret;
240
server *new_server = malloc(sizeof(server));
241
if(new_server == NULL){
242
perror_plus("malloc");
243
return false;
244
}
245
*new_server = (server){ .ip = strdup(ip),
246
.port = port,
247
.if_index = if_index,
248
.af = af };
249
if(new_server->ip == NULL){
250
perror_plus("strdup");
251
free(new_server);
252
return false;
253
}
254
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
255
if(ret == -1){
256
perror_plus("clock_gettime");
257
#ifdef __GNUC__
258
#pragma GCC diagnostic push
259
#pragma GCC diagnostic ignored "-Wcast-qual"
260
#endif
261
free((char *)(new_server->ip));
262
#ifdef __GNUC__
263
#pragma GCC diagnostic pop
264
#endif
265
free(new_server);
266
return false;
267
}
268
/* Special case of first server */
269
if(*current_server == NULL){
270
new_server->next = new_server;
271
new_server->prev = new_server;
272
*current_server = new_server;
273
} else {
274
/* Place the new server last in the list */
275
new_server->next = *current_server;
276
new_server->prev = (*current_server)->prev;
277
new_server->prev->next = new_server;
278
(*current_server)->prev = new_server;
279
}
280
return true;
281
}
282
283
/* Set effective uid to 0, return errno */
284
__attribute__((warn_unused_result))
285
int raise_privileges(void){
286
int old_errno = errno;
287
int ret = 0;
288
if(seteuid(0) == -1){
289
ret = errno;
290
}
291
errno = old_errno;
292
return ret;
293
}
294
295
/* Set effective and real user ID to 0. Return errno. */
296
__attribute__((warn_unused_result))
297
int raise_privileges_permanently(void){
298
int old_errno = errno;
299
int ret = raise_privileges();
300
if(ret != 0){
301
errno = old_errno;
302
return ret;
303
}
304
if(setuid(0) == -1){
305
ret = errno;
306
}
307
errno = old_errno;
308
return ret;
309
}
310
311
/* Set effective user ID to unprivileged saved user ID */
312
__attribute__((warn_unused_result))
313
int lower_privileges(void){
314
int old_errno = errno;
315
int ret = 0;
316
if(seteuid(uid) == -1){
317
ret = errno;
318
}
319
errno = old_errno;
320
return ret;
321
}
322
323
/* Lower privileges permanently */
324
__attribute__((warn_unused_result))
325
int lower_privileges_permanently(void){
326
int old_errno = errno;
327
int ret = 0;
328
if(setuid(uid) == -1){
329
ret = errno;
330
}
331
errno = old_errno;
332
return ret;
333
}
334
335
/*
336
* Initialize GPGME.
337
*/
338
__attribute__((nonnull, warn_unused_result))
339
static bool init_gpgme(const char * const seckey,
340
const char * const pubkey,
341
const char * const tempdir,
342
mandos_context *mc){
343
gpgme_error_t rc;
344
gpgme_engine_info_t engine_info;
345
346
/*
347
* Helper function to insert pub and seckey to the engine keyring.
348
*/
349
bool import_key(const char * const filename){
350
int ret;
351
int fd;
352
gpgme_data_t pgp_data;
353
354
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
355
if(fd == -1){
356
perror_plus("open");
357
return false;
358
}
359
360
/* Workaround for systems without a real-time clock; see also
361
Debian bug #894495: <https://bugs.debian.org/894495> */
362
do {
363
{
364
time_t currtime = time(NULL);
365
if(currtime != (time_t)-1){
366
struct tm tm;
367
if(gmtime_r(&currtime, &tm) == NULL) {
368
perror_plus("gmtime_r");
369
break;
370
}
371
if(tm.tm_year != 70 or tm.tm_mon != 0){
372
break;
373
}
374
if(debug){
375
fprintf_plus(stderr, "System clock is January 1970");
376
}
377
} else {
378
if(debug){
379
fprintf_plus(stderr, "System clock is invalid");
380
}
381
}
382
}
383
struct stat keystat;
384
ret = fstat(fd, &keystat);
385
if(ret != 0){
386
perror_plus("fstat");
387
break;
388
}
389
ret = raise_privileges();
390
if(ret != 0){
391
errno = ret;
392
perror_plus("Failed to raise privileges");
393
break;
394
}
395
if(debug){
396
fprintf_plus(stderr,
397
"Setting system clock to key file mtime");
398
}
399
time_t keytime = keystat.st_mtim.tv_sec;
400
if(stime(&keytime) != 0){
401
perror_plus("stime");
402
}
403
ret = lower_privileges();
404
if(ret != 0){
405
errno = ret;
406
perror_plus("Failed to lower privileges");
407
}
408
} while(false);
409
410
rc = gpgme_data_new_from_fd(&pgp_data, fd);
411
if(rc != GPG_ERR_NO_ERROR){
412
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
413
gpgme_strsource(rc), gpgme_strerror(rc));
414
return false;
415
}
416
417
rc = gpgme_op_import(mc->ctx, pgp_data);
418
if(rc != GPG_ERR_NO_ERROR){
419
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
420
gpgme_strsource(rc), gpgme_strerror(rc));
421
return false;
422
}
423
{
424
gpgme_import_result_t import_result
425
= gpgme_op_import_result(mc->ctx);
426
if((import_result->imported < 1
427
or import_result->not_imported > 0)
428
and import_result->unchanged == 0){
429
fprintf_plus(stderr, "bad gpgme_op_import_results:\n");
430
fprintf_plus(stderr,
431
"The total number of considered keys: %d\n",
432
import_result->considered);
433
fprintf_plus(stderr,
434
"The number of keys without user ID: %d\n",
435
import_result->no_user_id);
436
fprintf_plus(stderr,
437
"The total number of imported keys: %d\n",
438
import_result->imported);
439
fprintf_plus(stderr, "The number of imported RSA keys: %d\n",
440
import_result->imported_rsa);
441
fprintf_plus(stderr, "The number of unchanged keys: %d\n",
442
import_result->unchanged);
443
fprintf_plus(stderr, "The number of new user IDs: %d\n",
444
import_result->new_user_ids);
445
fprintf_plus(stderr, "The number of new sub keys: %d\n",
446
import_result->new_sub_keys);
447
fprintf_plus(stderr, "The number of new signatures: %d\n",
448
import_result->new_signatures);
449
fprintf_plus(stderr, "The number of new revocations: %d\n",
450
import_result->new_revocations);
451
fprintf_plus(stderr,
452
"The total number of secret keys read: %d\n",
453
import_result->secret_read);
454
fprintf_plus(stderr,
455
"The number of imported secret keys: %d\n",
456
import_result->secret_imported);
457
fprintf_plus(stderr,
458
"The number of unchanged secret keys: %d\n",
459
import_result->secret_unchanged);
460
fprintf_plus(stderr, "The number of keys not imported: %d\n",
461
import_result->not_imported);
462
for(gpgme_import_status_t import_status
463
= import_result->imports;
464
import_status != NULL;
465
import_status = import_status->next){
466
fprintf_plus(stderr, "Import status for key: %s\n",
467
import_status->fpr);
468
if(import_status->result != GPG_ERR_NO_ERROR){
469
fprintf_plus(stderr, "Import result: %s: %s\n",
470
gpgme_strsource(import_status->result),
471
gpgme_strerror(import_status->result));
472
}
473
fprintf_plus(stderr, "Key status:\n");
474
fprintf_plus(stderr,
475
import_status->status & GPGME_IMPORT_NEW
476
? "The key was new.\n"
477
: "The key was not new.\n");
478
fprintf_plus(stderr,
479
import_status->status & GPGME_IMPORT_UID
480
? "The key contained new user IDs.\n"
481
: "The key did not contain new user IDs.\n");
482
fprintf_plus(stderr,
483
import_status->status & GPGME_IMPORT_SIG
484
? "The key contained new signatures.\n"
485
: "The key did not contain new signatures.\n");
486
fprintf_plus(stderr,
487
import_status->status & GPGME_IMPORT_SUBKEY
488
? "The key contained new sub keys.\n"
489
: "The key did not contain new sub keys.\n");
490
fprintf_plus(stderr,
491
import_status->status & GPGME_IMPORT_SECRET
492
? "The key contained a secret key.\n"
493
: "The key did not contain a secret key.\n");
494
}
495
return false;
496
}
497
}
498
499
ret = close(fd);
500
if(ret == -1){
501
perror_plus("close");
502
}
503
gpgme_data_release(pgp_data);
504
return true;
505
}
506
507
if(debug){
508
fprintf_plus(stderr, "Initializing GPGME\n");
509
}
510
511
/* Init GPGME */
512
gpgme_check_version(NULL);
513
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
514
if(rc != GPG_ERR_NO_ERROR){
515
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
516
gpgme_strsource(rc), gpgme_strerror(rc));
517
return false;
518
}
519
520
/* Set GPGME home directory for the OpenPGP engine only */
521
rc = gpgme_get_engine_info(&engine_info);
522
if(rc != GPG_ERR_NO_ERROR){
523
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
524
gpgme_strsource(rc), gpgme_strerror(rc));
525
return false;
526
}
527
while(engine_info != NULL){
528
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
529
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
530
engine_info->file_name, tempdir);
531
break;
532
}
533
engine_info = engine_info->next;
534
}
535
if(engine_info == NULL){
536
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
537
tempdir);
538
return false;
539
}
540
541
/* Create new GPGME "context" */
542
rc = gpgme_new(&(mc->ctx));
543
if(rc != GPG_ERR_NO_ERROR){
544
fprintf_plus(stderr, "bad gpgme_new: %s: %s\n",
545
gpgme_strsource(rc), gpgme_strerror(rc));
546
return false;
547
}
548
549
if(not import_key(pubkey) or not import_key(seckey)){
550
return false;
551
}
552
553
return true;
554
}
555
556
/*
557
* Decrypt OpenPGP data.
558
* Returns -1 on error
559
*/
560
__attribute__((nonnull, warn_unused_result))
561
static ssize_t pgp_packet_decrypt(const char *cryptotext,
562
size_t crypto_size,
563
char **plaintext,
564
mandos_context *mc){
565
gpgme_data_t dh_crypto, dh_plain;
566
gpgme_error_t rc;
567
ssize_t ret;
568
size_t plaintext_capacity = 0;
569
ssize_t plaintext_length = 0;
570
571
if(debug){
572
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
573
}
574
575
/* Create new GPGME data buffer from memory cryptotext */
576
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
577
0);
578
if(rc != GPG_ERR_NO_ERROR){
579
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
580
gpgme_strsource(rc), gpgme_strerror(rc));
581
return -1;
582
}
583
584
/* Create new empty GPGME data buffer for the plaintext */
585
rc = gpgme_data_new(&dh_plain);
586
if(rc != GPG_ERR_NO_ERROR){
587
fprintf_plus(stderr, "bad gpgme_data_new: %s: %s\n",
588
gpgme_strsource(rc), gpgme_strerror(rc));
589
gpgme_data_release(dh_crypto);
590
return -1;
591
}
592
593
/* Decrypt data from the cryptotext data buffer to the plaintext
594
data buffer */
595
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
596
if(rc != GPG_ERR_NO_ERROR){
597
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
598
gpgme_strsource(rc), gpgme_strerror(rc));
599
plaintext_length = -1;
600
if(debug){
601
gpgme_decrypt_result_t result;
602
result = gpgme_op_decrypt_result(mc->ctx);
603
if(result == NULL){
604
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
605
} else {
606
if(result->unsupported_algorithm != NULL) {
607
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
608
result->unsupported_algorithm);
609
}
610
fprintf_plus(stderr, "Wrong key usage: %s\n",
611
result->wrong_key_usage ? "Yes" : "No");
612
if(result->file_name != NULL){
613
fprintf_plus(stderr, "File name: %s\n", result->file_name);
614
}
615
616
for(gpgme_recipient_t r = result->recipients; r != NULL;
617
r = r->next){
618
fprintf_plus(stderr, "Public key algorithm: %s\n",
619
gpgme_pubkey_algo_name(r->pubkey_algo));
620
fprintf_plus(stderr, "Key ID: %s\n", r->keyid);
621
fprintf_plus(stderr, "Secret key available: %s\n",
622
r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");
623
}
624
}
625
}
626
goto decrypt_end;
627
}
628
629
if(debug){
630
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
631
}
632
633
/* Seek back to the beginning of the GPGME plaintext data buffer */
634
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
635
perror_plus("gpgme_data_seek");
636
plaintext_length = -1;
637
goto decrypt_end;
638
}
639
640
*plaintext = NULL;
641
while(true){
642
plaintext_capacity = incbuffer(plaintext,
643
(size_t)plaintext_length,
644
plaintext_capacity);
645
if(plaintext_capacity == 0){
646
perror_plus("incbuffer");
647
plaintext_length = -1;
648
goto decrypt_end;
649
}
650
651
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
652
BUFFER_SIZE);
653
/* Print the data, if any */
654
if(ret == 0){
655
/* EOF */
656
break;
657
}
658
if(ret < 0){
659
perror_plus("gpgme_data_read");
660
plaintext_length = -1;
661
goto decrypt_end;
662
}
663
plaintext_length += ret;
664
}
665
666
if(debug){
667
fprintf_plus(stderr, "Decrypted password is: ");
668
for(ssize_t i = 0; i < plaintext_length; i++){
669
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
670
}
671
fprintf(stderr, "\n");
672
}
673
674
decrypt_end:
675
676
/* Delete the GPGME cryptotext data buffer */
677
gpgme_data_release(dh_crypto);
678
679
/* Delete the GPGME plaintext data buffer */
680
gpgme_data_release(dh_plain);
681
return plaintext_length;
682
}
683
684
__attribute__((warn_unused_result, const))
685
static const char *safe_string(const char *str){
686
if(str == NULL)
687
return "(unknown)";
688
return str;
689
}
690
691
__attribute__((warn_unused_result))
692
static const char *safer_gnutls_strerror(int value){
693
const char *ret = gnutls_strerror(value);
694
return safe_string(ret);
695
}
696
697
/* GnuTLS log function callback */
698
__attribute__((nonnull))
699
static void debuggnutls(__attribute__((unused)) int level,
700
const char* string){
701
fprintf_plus(stderr, "GnuTLS: %s", string);
702
}
703
704
__attribute__((nonnull(1, 2, 4), warn_unused_result))
705
static int init_gnutls_global(const char *pubkeyfilename,
706
const char *seckeyfilename,
707
const char *dhparamsfilename,
708
mandos_context *mc){
709
int ret;
710
711
if(debug){
712
fprintf_plus(stderr, "Initializing GnuTLS\n");
713
}
714
715
if(debug){
716
/* "Use a log level over 10 to enable all debugging options."
717
* - GnuTLS manual
718
*/
719
gnutls_global_set_log_level(11);
720
gnutls_global_set_log_function(debuggnutls);
721
}
722
723
/* OpenPGP credentials */
724
ret = gnutls_certificate_allocate_credentials(&mc->cred);
725
if(ret != GNUTLS_E_SUCCESS){
726
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
727
safer_gnutls_strerror(ret));
728
return -1;
729
}
730
731
if(debug){
732
fprintf_plus(stderr, "Attempting to use public key %s and"
733
" private key %s as GnuTLS credentials\n",
734
pubkeyfilename,
735
seckeyfilename);
736
}
737
738
#if GNUTLS_VERSION_NUMBER >= 0x030606
739
ret = gnutls_certificate_set_rawpk_key_file
740
(mc->cred, pubkeyfilename, seckeyfilename,
741
GNUTLS_X509_FMT_PEM, /* format */
742
NULL, /* pass */
743
/* key_usage */
744
GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
745
NULL, /* names */
746
0, /* names_length */
747
/* privkey_flags */
748
GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,
749
0); /* pkcs11_flags */
750
#elif GNUTLS_VERSION_NUMBER < 0x030600
751
ret = gnutls_certificate_set_openpgp_key_file
752
(mc->cred, pubkeyfilename, seckeyfilename,
753
GNUTLS_OPENPGP_FMT_BASE64);
754
#else
755
#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"
756
#endif
757
if(ret != GNUTLS_E_SUCCESS){
758
fprintf_plus(stderr,
759
"Error[%d] while reading the key pair ('%s',"
760
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
761
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
762
safer_gnutls_strerror(ret));
763
goto globalfail;
764
}
765
766
/* GnuTLS server initialization */
767
ret = gnutls_dh_params_init(&mc->dh_params);
768
if(ret != GNUTLS_E_SUCCESS){
769
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
770
" initialization: %s\n",
771
safer_gnutls_strerror(ret));
772
goto globalfail;
773
}
774
/* If a Diffie-Hellman parameters file was given, try to use it */
775
if(dhparamsfilename != NULL){
776
gnutls_datum_t params = { .data = NULL, .size = 0 };
777
do {
778
int dhpfile = open(dhparamsfilename, O_RDONLY);
779
if(dhpfile == -1){
780
perror_plus("open");
781
dhparamsfilename = NULL;
782
break;
783
}
784
size_t params_capacity = 0;
785
while(true){
786
params_capacity = incbuffer((char **)¶ms.data,
787
(size_t)params.size,
788
(size_t)params_capacity);
789
if(params_capacity == 0){
790
perror_plus("incbuffer");
791
free(params.data);
792
params.data = NULL;
793
dhparamsfilename = NULL;
794
break;
795
}
796
ssize_t bytes_read = read(dhpfile,
797
params.data + params.size,
798
BUFFER_SIZE);
799
/* EOF */
800
if(bytes_read == 0){
801
break;
802
}
803
/* check bytes_read for failure */
804
if(bytes_read < 0){
805
perror_plus("read");
806
free(params.data);
807
params.data = NULL;
808
dhparamsfilename = NULL;
809
break;
810
}
811
params.size += (unsigned int)bytes_read;
812
}
813
ret = close(dhpfile);
814
if(ret == -1){
815
perror_plus("close");
816
}
817
if(params.data == NULL){
818
dhparamsfilename = NULL;
819
}
820
if(dhparamsfilename == NULL){
821
break;
822
}
823
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
824
GNUTLS_X509_FMT_PEM);
825
if(ret != GNUTLS_E_SUCCESS){
826
fprintf_plus(stderr, "Failed to parse DH parameters in file"
827
" \"%s\": %s\n", dhparamsfilename,
828
safer_gnutls_strerror(ret));
829
dhparamsfilename = NULL;
830
}
831
free(params.data);
832
} while(false);
833
}
834
if(dhparamsfilename == NULL){
835
if(mc->dh_bits == 0){
836
#if GNUTLS_VERSION_NUMBER < 0x030600
837
/* Find out the optimal number of DH bits */
838
/* Try to read the private key file */
839
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
840
do {
841
int secfile = open(seckeyfilename, O_RDONLY);
842
if(secfile == -1){
843
perror_plus("open");
844
break;
845
}
846
size_t buffer_capacity = 0;
847
while(true){
848
buffer_capacity = incbuffer((char **)&buffer.data,
849
(size_t)buffer.size,
850
(size_t)buffer_capacity);
851
if(buffer_capacity == 0){
852
perror_plus("incbuffer");
853
free(buffer.data);
854
buffer.data = NULL;
855
break;
856
}
857
ssize_t bytes_read = read(secfile,
858
buffer.data + buffer.size,
859
BUFFER_SIZE);
860
/* EOF */
861
if(bytes_read == 0){
862
break;
863
}
864
/* check bytes_read for failure */
865
if(bytes_read < 0){
866
perror_plus("read");
867
free(buffer.data);
868
buffer.data = NULL;
869
break;
870
}
871
buffer.size += (unsigned int)bytes_read;
872
}
873
close(secfile);
874
} while(false);
875
/* If successful, use buffer to parse private key */
876
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
877
if(buffer.data != NULL){
878
{
879
gnutls_openpgp_privkey_t privkey = NULL;
880
ret = gnutls_openpgp_privkey_init(&privkey);
881
if(ret != GNUTLS_E_SUCCESS){
882
fprintf_plus(stderr, "Error initializing OpenPGP key"
883
" structure: %s",
884
safer_gnutls_strerror(ret));
885
free(buffer.data);
886
buffer.data = NULL;
887
} else {
888
ret = gnutls_openpgp_privkey_import
889
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
890
if(ret != GNUTLS_E_SUCCESS){
891
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
892
safer_gnutls_strerror(ret));
893
privkey = NULL;
894
}
895
free(buffer.data);
896
buffer.data = NULL;
897
if(privkey != NULL){
898
/* Use private key to suggest an appropriate
899
sec_param */
900
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
901
gnutls_openpgp_privkey_deinit(privkey);
902
if(debug){
903
fprintf_plus(stderr, "This OpenPGP key implies using"
904
" a GnuTLS security parameter \"%s\".\n",
905
safe_string(gnutls_sec_param_get_name
906
(sec_param)));
907
}
908
}
909
}
910
}
911
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
912
/* Err on the side of caution */
913
sec_param = GNUTLS_SEC_PARAM_ULTRA;
914
if(debug){
915
fprintf_plus(stderr, "Falling back to security parameter"
916
" \"%s\"\n",
917
safe_string(gnutls_sec_param_get_name
918
(sec_param)));
919
}
920
}
921
}
922
unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
923
if(uret != 0){
924
mc->dh_bits = uret;
925
if(debug){
926
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
927
" implies %u DH bits; using that.\n",
928
safe_string(gnutls_sec_param_get_name
929
(sec_param)),
930
mc->dh_bits);
931
}
932
} else {
933
fprintf_plus(stderr, "Failed to get implied number of DH"
934
" bits for security parameter \"%s\"): %s\n",
935
safe_string(gnutls_sec_param_get_name
936
(sec_param)),
937
safer_gnutls_strerror(ret));
938
goto globalfail;
939
}
940
#endif
941
} else { /* dh_bits != 0 */
942
if(debug){
943
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
944
mc->dh_bits);
945
}
946
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
947
if(ret != GNUTLS_E_SUCCESS){
948
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
949
" bits): %s\n", mc->dh_bits,
950
safer_gnutls_strerror(ret));
951
goto globalfail;
952
}
953
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
954
}
955
}
956
957
return 0;
958
959
globalfail:
960
961
gnutls_certificate_free_credentials(mc->cred);
962
gnutls_dh_params_deinit(mc->dh_params);
963
return -1;
964
}
965
966
__attribute__((nonnull, warn_unused_result))
967
static int init_gnutls_session(gnutls_session_t *session,
968
mandos_context *mc){
969
int ret;
970
/* GnuTLS session creation */
971
do {
972
ret = gnutls_init(session, (GNUTLS_SERVER
973
#if GNUTLS_VERSION_NUMBER >= 0x030506
974
| GNUTLS_NO_TICKETS
975
#endif
976
#if GNUTLS_VERSION_NUMBER >= 0x030606
977
| GNUTLS_ENABLE_RAWPK
978
#endif
979
));
980
if(quit_now){
981
return -1;
982
}
983
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
984
if(ret != GNUTLS_E_SUCCESS){
985
fprintf_plus(stderr,
986
"Error in GnuTLS session initialization: %s\n",
987
safer_gnutls_strerror(ret));
988
}
989
990
{
991
const char *err;
992
do {
993
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
994
if(quit_now){
995
gnutls_deinit(*session);
996
return -1;
997
}
998
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
999
if(ret != GNUTLS_E_SUCCESS){
1000
fprintf_plus(stderr, "Syntax error at: %s\n", err);
1001
fprintf_plus(stderr, "GnuTLS error: %s\n",
1002
safer_gnutls_strerror(ret));
1003
gnutls_deinit(*session);
1004
return -1;
1005
}
1006
}
1007
1008
do {
1009
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
1010
mc->cred);
1011
if(quit_now){
1012
gnutls_deinit(*session);
1013
return -1;
1014
}
1015
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
1016
if(ret != GNUTLS_E_SUCCESS){
1017
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
1018
safer_gnutls_strerror(ret));
1019
gnutls_deinit(*session);
1020
return -1;
1021
}
1022
1023
/* ignore client certificate if any. */
1024
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
1025
1026
return 0;
1027
}
1028
1029
/* Avahi log function callback */
1030
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
1031
__attribute__((unused)) const char *txt){}
1032
1033
/* Helper function to add_local_route() and delete_local_route() */
1034
__attribute__((nonnull, warn_unused_result))
1035
static bool add_delete_local_route(const bool add,
1036
const char *address,
1037
AvahiIfIndex if_index){
1038
int ret;
1039
char helper[] = "mandos-client-iprouteadddel";
1040
char add_arg[] = "add";
1041
char delete_arg[] = "delete";
1042
char debug_flag[] = "--debug";
1043
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
1044
if(pluginhelperdir == NULL){
1045
if(debug){
1046
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
1047
" variable not set; cannot run helper\n");
1048
}
1049
return false;
1050
}
1051
1052
char interface[IF_NAMESIZE];
1053
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1054
perror_plus("if_indextoname");
1055
return false;
1056
}
1057
1058
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1059
if(devnull == -1){
1060
perror_plus("open(\"/dev/null\", O_RDONLY)");
1061
return false;
1062
}
1063
pid_t pid = fork();
1064
if(pid == 0){
1065
/* Child */
1066
/* Raise privileges */
1067
errno = raise_privileges_permanently();
1068
if(errno != 0){
1069
perror_plus("Failed to raise privileges");
1070
/* _exit(EX_NOPERM); */
1071
} else {
1072
/* Set group */
1073
errno = 0;
1074
ret = setgid(0);
1075
if(ret == -1){
1076
perror_plus("setgid");
1077
_exit(EX_NOPERM);
1078
}
1079
/* Reset supplementary groups */
1080
errno = 0;
1081
ret = setgroups(0, NULL);
1082
if(ret == -1){
1083
perror_plus("setgroups");
1084
_exit(EX_NOPERM);
1085
}
1086
}
1087
ret = dup2(devnull, STDIN_FILENO);
1088
if(ret == -1){
1089
perror_plus("dup2(devnull, STDIN_FILENO)");
1090
_exit(EX_OSERR);
1091
}
1092
ret = close(devnull);
1093
if(ret == -1){
1094
perror_plus("close");
1095
_exit(EX_OSERR);
1096
}
1097
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1098
if(ret == -1){
1099
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1100
_exit(EX_OSERR);
1101
}
1102
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
1103
O_RDONLY
1104
| O_DIRECTORY
1105
| O_PATH
1106
| O_CLOEXEC));
1107
if(helperdir_fd == -1){
1108
perror_plus("open");
1109
_exit(EX_UNAVAILABLE);
1110
}
1111
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
1112
helper, O_RDONLY));
1113
if(helper_fd == -1){
1114
perror_plus("openat");
1115
close(helperdir_fd);
1116
_exit(EX_UNAVAILABLE);
1117
}
1118
close(helperdir_fd);
1119
#ifdef __GNUC__
1120
#pragma GCC diagnostic push
1121
#pragma GCC diagnostic ignored "-Wcast-qual"
1122
#endif
1123
if(fexecve(helper_fd, (char *const [])
1124
{ helper, add ? add_arg : delete_arg, (char *)address,
1125
interface, debug ? debug_flag : NULL, NULL },
1126
environ) == -1){
1127
#ifdef __GNUC__
1128
#pragma GCC diagnostic pop
1129
#endif
1130
perror_plus("fexecve");
1131
_exit(EXIT_FAILURE);
1132
}
1133
}
1134
if(pid == -1){
1135
perror_plus("fork");
1136
return false;
1137
}
1138
int status;
1139
pid_t pret = -1;
1140
errno = 0;
1141
do {
1142
pret = waitpid(pid, &status, 0);
1143
if(pret == -1 and errno == EINTR and quit_now){
1144
int errno_raising = 0;
1145
if((errno = raise_privileges()) != 0){
1146
errno_raising = errno;
1147
perror_plus("Failed to raise privileges in order to"
1148
" kill helper program");
1149
}
1150
if(kill(pid, SIGTERM) == -1){
1151
perror_plus("kill");
1152
}
1153
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
1154
perror_plus("Failed to lower privileges after killing"
1155
" helper program");
1156
}
1157
return false;
1158
}
1159
} while(pret == -1 and errno == EINTR);
1160
if(pret == -1){
1161
perror_plus("waitpid");
1162
return false;
1163
}
1164
if(WIFEXITED(status)){
1165
if(WEXITSTATUS(status) != 0){
1166
fprintf_plus(stderr, "Error: iprouteadddel exited"
1167
" with status %d\n", WEXITSTATUS(status));
1168
return false;
1169
}
1170
return true;
1171
}
1172
if(WIFSIGNALED(status)){
1173
fprintf_plus(stderr, "Error: iprouteadddel died by"
1174
" signal %d\n", WTERMSIG(status));
1175
return false;
1176
}
1177
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1178
return false;
1179
}
1180
1181
__attribute__((nonnull, warn_unused_result))
1182
static bool add_local_route(const char *address,
1183
AvahiIfIndex if_index){
1184
if(debug){
1185
fprintf_plus(stderr, "Adding route to %s\n", address);
1186
}
1187
return add_delete_local_route(true, address, if_index);
1188
}
1189
1190
__attribute__((nonnull, warn_unused_result))
1191
static bool delete_local_route(const char *address,
1192
AvahiIfIndex if_index){
1193
if(debug){
1194
fprintf_plus(stderr, "Removing route to %s\n", address);
1195
}
1196
return add_delete_local_route(false, address, if_index);
1197
}
1198
1199
/* Called when a Mandos server is found */
1200
__attribute__((nonnull, warn_unused_result))
1201
static int start_mandos_communication(const char *ip, in_port_t port,
1202
AvahiIfIndex if_index,
1203
int af, mandos_context *mc){
1204
int ret, tcp_sd = -1;
1205
ssize_t sret;
1206
struct sockaddr_storage to;
1207
char *buffer = NULL;
1208
char *decrypted_buffer = NULL;
1209
size_t buffer_length = 0;
1210
size_t buffer_capacity = 0;
1211
size_t written;
1212
int retval = -1;
1213
gnutls_session_t session;
1214
int pf; /* Protocol family */
1215
bool route_added = false;
1216
1217
errno = 0;
1218
1219
if(quit_now){
1220
errno = EINTR;
1221
return -1;
1222
}
1223
1224
switch(af){
1225
case AF_INET6:
1226
pf = PF_INET6;
1227
break;
1228
case AF_INET:
1229
pf = PF_INET;
1230
break;
1231
default:
1232
fprintf_plus(stderr, "Bad address family: %d\n", af);
1233
errno = EINVAL;
1234
return -1;
1235
}
1236
1237
/* If the interface is specified and we have a list of interfaces */
1238
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1239
/* Check if the interface is one of the interfaces we are using */
1240
bool match = false;
1241
{
1242
char *interface = NULL;
1243
while((interface = argz_next(mc->interfaces,
1244
mc->interfaces_size,
1245
interface))){
1246
if(if_nametoindex(interface) == (unsigned int)if_index){
1247
match = true;
1248
break;
1249
}
1250
}
1251
}
1252
if(not match){
1253
/* This interface does not match any in the list, so we don't
1254
connect to the server */
1255
if(debug){
1256
char interface[IF_NAMESIZE];
1257
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1258
perror_plus("if_indextoname");
1259
} else {
1260
fprintf_plus(stderr, "Skipping server on non-used interface"
1261
" \"%s\"\n",
1262
if_indextoname((unsigned int)if_index,
1263
interface));
1264
}
1265
}
1266
return -1;
1267
}
1268
}
1269
1270
ret = init_gnutls_session(&session, mc);
1271
if(ret != 0){
1272
return -1;
1273
}
1274
1275
if(debug){
1276
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
1277
PRIuMAX "\n", ip, (uintmax_t)port);
1278
}
1279
1280
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
1281
if(tcp_sd < 0){
1282
int e = errno;
1283
perror_plus("socket");
1284
errno = e;
1285
goto mandos_end;
1286
}
1287
1288
if(quit_now){
1289
errno = EINTR;
1290
goto mandos_end;
1291
}
1292
1293
if(af == AF_INET6){
1294
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1295
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1296
ret = inet_pton(af, ip, &to6->sin6_addr);
1297
} else { /* IPv4 */
1298
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1299
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1300
ret = inet_pton(af, ip, &to4->sin_addr);
1301
}
1302
if(ret < 0 ){
1303
int e = errno;
1304
perror_plus("inet_pton");
1305
errno = e;
1306
goto mandos_end;
1307
}
1308
if(ret == 0){
1309
int e = errno;
1310
fprintf_plus(stderr, "Bad address: %s\n", ip);
1311
errno = e;
1312
goto mandos_end;
1313
}
1314
if(af == AF_INET6){
1315
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1316
if(IN6_IS_ADDR_LINKLOCAL
1317
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
1318
if(if_index == AVAHI_IF_UNSPEC){
1319
fprintf_plus(stderr, "An IPv6 link-local address is"
1320
" incomplete without a network interface\n");
1321
errno = EINVAL;
1322
goto mandos_end;
1323
}
1324
/* Set the network interface number as scope */
1325
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
1326
}
1327
} else {
1328
((struct sockaddr_in *)&to)->sin_port = htons(port);
1329
}
1330
1331
if(quit_now){
1332
errno = EINTR;
1333
goto mandos_end;
1334
}
1335
1336
if(debug){
1337
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
1338
char interface[IF_NAMESIZE];
1339
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1340
perror_plus("if_indextoname");
1341
} else {
1342
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
1343
"\n", ip, interface, (uintmax_t)port);
1344
}
1345
} else {
1346
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1347
ip, (uintmax_t)port);
1348
}
1349
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
1350
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1351
if(af == AF_INET6){
1352
ret = getnameinfo((struct sockaddr *)&to,
1353
sizeof(struct sockaddr_in6),
1354
addrstr, sizeof(addrstr), NULL, 0,
1355
NI_NUMERICHOST);
1356
} else {
1357
ret = getnameinfo((struct sockaddr *)&to,
1358
sizeof(struct sockaddr_in),
1359
addrstr, sizeof(addrstr), NULL, 0,
1360
NI_NUMERICHOST);
1361
}
1362
if(ret == EAI_SYSTEM){
1363
perror_plus("getnameinfo");
1364
} else if(ret != 0) {
1365
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1366
} else if(strcmp(addrstr, ip) != 0){
1367
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1368
}
1369
}
1370
1371
if(quit_now){
1372
errno = EINTR;
1373
goto mandos_end;
1374
}
1375
1376
while(true){
1377
if(af == AF_INET6){
1378
ret = connect(tcp_sd, (struct sockaddr *)&to,
1379
sizeof(struct sockaddr_in6));
1380
} else {
1381
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1382
sizeof(struct sockaddr_in));
1383
}
1384
if(ret < 0){
1385
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1386
and if_index != AVAHI_IF_UNSPEC
1387
and connect_to == NULL
1388
and not route_added and
1389
((af == AF_INET6 and not
1390
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1391
&to)->sin6_addr)))
1392
or (af == AF_INET and
1393
/* Not a a IPv4LL address */
1394
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1395
& 0xFFFF0000L) != 0xA9FE0000L))){
1396
/* Work around Avahi bug - Avahi does not announce link-local
1397
addresses if it has a global address, so local hosts with
1398
*only* a link-local address (e.g. Mandos clients) cannot
1399
connect to a Mandos server announced by Avahi on a server
1400
host with a global address. Work around this by retrying
1401
with an explicit route added with the server's address.
1402
1403
Avahi bug reference:
1404
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1405
https://bugs.debian.org/587961
1406
*/
1407
if(debug){
1408
fprintf_plus(stderr, "Mandos server unreachable, trying"
1409
" direct route\n");
1410
}
1411
int e = errno;
1412
route_added = add_local_route(ip, if_index);
1413
if(route_added){
1414
continue;
1415
}
1416
errno = e;
1417
}
1418
if(errno != ECONNREFUSED or debug){
1419
int e = errno;
1420
perror_plus("connect");
1421
errno = e;
1422
}
1423
goto mandos_end;
1424
}
1425
1426
if(quit_now){
1427
errno = EINTR;
1428
goto mandos_end;
1429
}
1430
break;
1431
}
1432
1433
const char *out = mandos_protocol_version;
1434
written = 0;
1435
while(true){
1436
size_t out_size = strlen(out);
1437
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
1438
out_size - written));
1439
if(ret == -1){
1440
int e = errno;
1441
perror_plus("write");
1442
errno = e;
1443
goto mandos_end;
1444
}
1445
written += (size_t)ret;
1446
if(written < out_size){
1447
continue;
1448
} else {
1449
if(out == mandos_protocol_version){
1450
written = 0;
1451
out = "\r\n";
1452
} else {
1453
break;
1454
}
1455
}
1456
1457
if(quit_now){
1458
errno = EINTR;
1459
goto mandos_end;
1460
}
1461
}
1462
1463
if(debug){
1464
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
1465
}
1466
1467
if(quit_now){
1468
errno = EINTR;
1469
goto mandos_end;
1470
}
1471
1472
/* This casting via intptr_t is to eliminate warning about casting
1473
an int to a pointer type. This is exactly how the GnuTLS Guile
1474
function "set-session-transport-fd!" does it. */
1475
gnutls_transport_set_ptr(session,
1476
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
1477
1478
if(quit_now){
1479
errno = EINTR;
1480
goto mandos_end;
1481
}
1482
1483
do {
1484
ret = gnutls_handshake(session);
1485
if(quit_now){
1486
errno = EINTR;
1487
goto mandos_end;
1488
}
1489
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1490
1491
if(ret != GNUTLS_E_SUCCESS){
1492
if(debug){
1493
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
1494
gnutls_perror(ret);
1495
}
1496
errno = EPROTO;
1497
goto mandos_end;
1498
}
1499
1500
/* Read OpenPGP packet that contains the wanted password */
1501
1502
if(debug){
1503
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
1504
" %s\n", ip);
1505
}
1506
1507
while(true){
1508
1509
if(quit_now){
1510
errno = EINTR;
1511
goto mandos_end;
1512
}
1513
1514
buffer_capacity = incbuffer(&buffer, buffer_length,
1515
buffer_capacity);
1516
if(buffer_capacity == 0){
1517
int e = errno;
1518
perror_plus("incbuffer");
1519
errno = e;
1520
goto mandos_end;
1521
}
1522
1523
if(quit_now){
1524
errno = EINTR;
1525
goto mandos_end;
1526
}
1527
1528
sret = gnutls_record_recv(session, buffer+buffer_length,
1529
BUFFER_SIZE);
1530
if(sret == 0){
1531
break;
1532
}
1533
if(sret < 0){
1534
switch(sret){
1535
case GNUTLS_E_INTERRUPTED:
1536
case GNUTLS_E_AGAIN:
1537
break;
1538
case GNUTLS_E_REHANDSHAKE:
1539
do {
1540
ret = gnutls_handshake(session);
1541
1542
if(quit_now){
1543
errno = EINTR;
1544
goto mandos_end;
1545
}
1546
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1547
if(ret < 0){
1548
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
1549
"***\n");
1550
gnutls_perror(ret);
1551
errno = EPROTO;
1552
goto mandos_end;
1553
}
1554
break;
1555
default:
1556
fprintf_plus(stderr, "Unknown error while reading data from"
1557
" encrypted session with Mandos server\n");
1558
gnutls_bye(session, GNUTLS_SHUT_RDWR);
1559
errno = EIO;
1560
goto mandos_end;
1561
}
1562
} else {
1563
buffer_length += (size_t) sret;
1564
}
1565
}
1566
1567
if(debug){
1568
fprintf_plus(stderr, "Closing TLS session\n");
1569
}
1570
1571
if(quit_now){
1572
errno = EINTR;
1573
goto mandos_end;
1574
}
1575
1576
do {
1577
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
1578
if(quit_now){
1579
errno = EINTR;
1580
goto mandos_end;
1581
}
1582
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1583
1584
if(buffer_length > 0){
1585
ssize_t decrypted_buffer_size;
1586
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
1587
&decrypted_buffer, mc);
1588
if(decrypted_buffer_size >= 0){
1589
1590
clearerr(stdout);
1591
written = 0;
1592
while(written < (size_t) decrypted_buffer_size){
1593
if(quit_now){
1594
errno = EINTR;
1595
goto mandos_end;
1596
}
1597
1598
ret = (int)fwrite(decrypted_buffer + written, 1,
1599
(size_t)decrypted_buffer_size - written,
1600
stdout);
1601
if(ret == 0 and ferror(stdout)){
1602
int e = errno;
1603
if(debug){
1604
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1605
strerror(errno));
1606
}
1607
errno = e;
1608
goto mandos_end;
1609
}
1610
written += (size_t)ret;
1611
}
1612
ret = fflush(stdout);
1613
if(ret != 0){
1614
int e = errno;
1615
if(debug){
1616
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1617
strerror(errno));
1618
}
1619
errno = e;
1620
goto mandos_end;
1621
}
1622
retval = 0;
1623
}
1624
}
1625
1626
/* Shutdown procedure */
1627
1628
mandos_end:
1629
{
1630
if(route_added){
1631
if(not delete_local_route(ip, if_index)){
1632
fprintf_plus(stderr, "Failed to delete local route to %s on"
1633
" interface %d", ip, if_index);
1634
}
1635
}
1636
int e = errno;
1637
free(decrypted_buffer);
1638
free(buffer);
1639
if(tcp_sd >= 0){
1640
ret = close(tcp_sd);
1641
}
1642
if(ret == -1){
1643
if(e == 0){
1644
e = errno;
1645
}
1646
perror_plus("close");
1647
}
1648
gnutls_deinit(session);
1649
errno = e;
1650
if(quit_now){
1651
errno = EINTR;
1652
retval = -1;
1653
}
1654
}
1655
return retval;
1656
}
1657
1658
static void resolve_callback(AvahiSServiceResolver *r,
1659
AvahiIfIndex interface,
1660
AvahiProtocol proto,
1661
AvahiResolverEvent event,
1662
const char *name,
1663
const char *type,
1664
const char *domain,
1665
const char *host_name,
1666
const AvahiAddress *address,
1667
uint16_t port,
1668
AVAHI_GCC_UNUSED AvahiStringList *txt,
1669
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1670
flags,
1671
void *mc){
1672
if(r == NULL){
1673
return;
1674
}
1675
1676
/* Called whenever a service has been resolved successfully or
1677
timed out */
1678
1679
if(quit_now){
1680
avahi_s_service_resolver_free(r);
1681
return;
1682
}
1683
1684
switch(event){
1685
default:
1686
case AVAHI_RESOLVER_FAILURE:
1687
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1688
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1689
domain,
1690
avahi_strerror(avahi_server_errno
1691
(((mandos_context*)mc)->server)));
1692
break;
1693
1694
case AVAHI_RESOLVER_FOUND:
1695
{
1696
char ip[AVAHI_ADDRESS_STR_MAX];
1697
avahi_address_snprint(ip, sizeof(ip), address);
1698
if(debug){
1699
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1700
PRIdMAX ") on port %" PRIu16 "\n", name,
1701
host_name, ip, (intmax_t)interface, port);
1702
}
1703
int ret = start_mandos_communication(ip, (in_port_t)port,
1704
interface,
1705
avahi_proto_to_af(proto),
1706
mc);
1707
if(ret == 0){
1708
avahi_simple_poll_quit(simple_poll);
1709
} else {
1710
if(not add_server(ip, (in_port_t)port, interface,
1711
avahi_proto_to_af(proto),
1712
&((mandos_context*)mc)->current_server)){
1713
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1714
" list\n", name);
1715
}
1716
}
1717
}
1718
}
1719
avahi_s_service_resolver_free(r);
1720
}
1721
1722
static void browse_callback(AvahiSServiceBrowser *b,
1723
AvahiIfIndex interface,
1724
AvahiProtocol protocol,
1725
AvahiBrowserEvent event,
1726
const char *name,
1727
const char *type,
1728
const char *domain,
1729
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1730
flags,
1731
void *mc){
1732
if(b == NULL){
1733
return;
1734
}
1735
1736
/* Called whenever a new services becomes available on the LAN or
1737
is removed from the LAN */
1738
1739
if(quit_now){
1740
return;
1741
}
1742
1743
switch(event){
1744
default:
1745
case AVAHI_BROWSER_FAILURE:
1746
1747
fprintf_plus(stderr, "(Avahi browser) %s\n",
1748
avahi_strerror(avahi_server_errno
1749
(((mandos_context*)mc)->server)));
1750
avahi_simple_poll_quit(simple_poll);
1751
return;
1752
1753
case AVAHI_BROWSER_NEW:
1754
/* We ignore the returned Avahi resolver object. In the callback
1755
function we free it. If the Avahi server is terminated before
1756
the callback function is called the Avahi server will free the
1757
resolver for us. */
1758
1759
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1760
interface, protocol, name, type,
1761
domain, protocol, 0,
1762
resolve_callback, mc) == NULL)
1763
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1764
" %s\n", name,
1765
avahi_strerror(avahi_server_errno
1766
(((mandos_context*)mc)->server)));
1767
break;
1768
1769
case AVAHI_BROWSER_REMOVE:
1770
break;
1771
1772
case AVAHI_BROWSER_ALL_FOR_NOW:
1773
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1774
if(debug){
1775
fprintf_plus(stderr, "No Mandos server found, still"
1776
" searching...\n");
1777
}
1778
break;
1779
}
1780
}
1781
1782
/* Signal handler that stops main loop after SIGTERM */
1783
static void handle_sigterm(int sig){
1784
if(quit_now){
1785
return;
1786
}
1787
quit_now = 1;
1788
signal_received = sig;
1789
int old_errno = errno;
1790
/* set main loop to exit */
1791
if(simple_poll != NULL){
1792
avahi_simple_poll_quit(simple_poll);
1793
}
1794
errno = old_errno;
1795
}
1796
1797
__attribute__((nonnull, warn_unused_result))
1798
bool get_flags(const char *ifname, struct ifreq *ifr){
1799
int ret;
1800
int old_errno;
1801
1802
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1803
if(s < 0){
1804
old_errno = errno;
1805
perror_plus("socket");
1806
errno = old_errno;
1807
return false;
1808
}
1809
strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);
1810
ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */
1811
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1812
if(ret == -1){
1813
if(debug){
1814
old_errno = errno;
1815
perror_plus("ioctl SIOCGIFFLAGS");
1816
errno = old_errno;
1817
}
1818
if((close(s) == -1) and debug){
1819
old_errno = errno;
1820
perror_plus("close");
1821
errno = old_errno;
1822
}
1823
return false;
1824
}
1825
if((close(s) == -1) and debug){
1826
old_errno = errno;
1827
perror_plus("close");
1828
errno = old_errno;
1829
}
1830
return true;
1831
}
1832
1833
__attribute__((nonnull, warn_unused_result))
1834
bool good_flags(const char *ifname, const struct ifreq *ifr){
1835
1836
/* Reject the loopback device */
1837
if(ifr->ifr_flags & IFF_LOOPBACK){
1838
if(debug){
1839
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1840
ifname);
1841
}
1842
return false;
1843
}
1844
/* Accept point-to-point devices only if connect_to is specified */
1845
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1846
if(debug){
1847
fprintf_plus(stderr, "Accepting point-to-point interface"
1848
" \"%s\"\n", ifname);
1849
}
1850
return true;
1851
}
1852
/* Otherwise, reject non-broadcast-capable devices */
1853
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1854
if(debug){
1855
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1856
" \"%s\"\n", ifname);
1857
}
1858
return false;
1859
}
1860
/* Reject non-ARP interfaces (including dummy interfaces) */
1861
if(ifr->ifr_flags & IFF_NOARP){
1862
if(debug){
1863
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1864
ifname);
1865
}
1866
return false;
1867
}
1868
1869
/* Accept this device */
1870
if(debug){
1871
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1872
}
1873
return true;
1874
}
1875
1876
/*
1877
* This function determines if a directory entry in /sys/class/net
1878
* corresponds to an acceptable network device.
1879
* (This function is passed to scandir(3) as a filter function.)
1880
*/
1881
__attribute__((nonnull, warn_unused_result))
1882
int good_interface(const struct dirent *if_entry){
1883
if(if_entry->d_name[0] == '.'){
1884
return 0;
1885
}
1886
1887
struct ifreq ifr;
1888
if(not get_flags(if_entry->d_name, &ifr)){
1889
if(debug){
1890
fprintf_plus(stderr, "Failed to get flags for interface "
1891
"\"%s\"\n", if_entry->d_name);
1892
}
1893
return 0;
1894
}
1895
1896
if(not good_flags(if_entry->d_name, &ifr)){
1897
return 0;
1898
}
1899
return 1;
1900
}
1901
1902
/*
1903
* This function determines if a network interface is up.
1904
*/
1905
__attribute__((nonnull, warn_unused_result))
1906
bool interface_is_up(const char *interface){
1907
struct ifreq ifr;
1908
if(not get_flags(interface, &ifr)){
1909
if(debug){
1910
fprintf_plus(stderr, "Failed to get flags for interface "
1911
"\"%s\"\n", interface);
1912
}
1913
return false;
1914
}
1915
1916
return (bool)(ifr.ifr_flags & IFF_UP);
1917
}
1918
1919
/*
1920
* This function determines if a network interface is running
1921
*/
1922
__attribute__((nonnull, warn_unused_result))
1923
bool interface_is_running(const char *interface){
1924
struct ifreq ifr;
1925
if(not get_flags(interface, &ifr)){
1926
if(debug){
1927
fprintf_plus(stderr, "Failed to get flags for interface "
1928
"\"%s\"\n", interface);
1929
}
1930
return false;
1931
}
1932
1933
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1934
}
1935
1936
__attribute__((nonnull, pure, warn_unused_result))
1937
int notdotentries(const struct dirent *direntry){
1938
/* Skip "." and ".." */
1939
if(direntry->d_name[0] == '.'
1940
and (direntry->d_name[1] == '\0'
1941
or (direntry->d_name[1] == '.'
1942
and direntry->d_name[2] == '\0'))){
1943
return 0;
1944
}
1945
return 1;
1946
}
1947
1948
/* Is this directory entry a runnable program? */
1949
__attribute__((nonnull, warn_unused_result))
1950
int runnable_hook(const struct dirent *direntry){
1951
int ret;
1952
size_t sret;
1953
struct stat st;
1954
1955
if((direntry->d_name)[0] == '\0'){
1956
/* Empty name? */
1957
return 0;
1958
}
1959
1960
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1961
"abcdefghijklmnopqrstuvwxyz"
1962
"0123456789"
1963
"_.-");
1964
if((direntry->d_name)[sret] != '\0'){
1965
/* Contains non-allowed characters */
1966
if(debug){
1967
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1968
direntry->d_name);
1969
}
1970
return 0;
1971
}
1972
1973
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1974
if(ret == -1){
1975
if(debug){
1976
perror_plus("Could not stat hook");
1977
}
1978
return 0;
1979
}
1980
if(not (S_ISREG(st.st_mode))){
1981
/* Not a regular file */
1982
if(debug){
1983
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1984
direntry->d_name);
1985
}
1986
return 0;
1987
}
1988
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1989
/* Not executable */
1990
if(debug){
1991
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1992
direntry->d_name);
1993
}
1994
return 0;
1995
}
1996
if(debug){
1997
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1998
direntry->d_name);
1999
}
2000
return 1;
2001
}
2002
2003
__attribute__((nonnull, warn_unused_result))
2004
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
2005
mandos_context *mc){
2006
int ret;
2007
struct timespec now;
2008
struct timespec waited_time;
2009
intmax_t block_time;
2010
2011
while(true){
2012
if(mc->current_server == NULL){
2013
if(debug){
2014
fprintf_plus(stderr, "Wait until first server is found."
2015
" No timeout!\n");
2016
}
2017
ret = avahi_simple_poll_iterate(s, -1);
2018
} else {
2019
if(debug){
2020
fprintf_plus(stderr, "Check current_server if we should run"
2021
" it, or wait\n");
2022
}
2023
/* the current time */
2024
ret = clock_gettime(CLOCK_MONOTONIC, &now);
2025
if(ret == -1){
2026
perror_plus("clock_gettime");
2027
return -1;
2028
}
2029
/* Calculating in ms how long time between now and server
2030
who we visted longest time ago. Now - last seen. */
2031
waited_time.tv_sec = (now.tv_sec
2032
- mc->current_server->last_seen.tv_sec);
2033
waited_time.tv_nsec = (now.tv_nsec
2034
- mc->current_server->last_seen.tv_nsec);
2035
/* total time is 10s/10,000ms.
2036
Converting to s from ms by dividing by 1,000,
2037
and ns to ms by dividing by 1,000,000. */
2038
block_time = ((retry_interval
2039
- ((intmax_t)waited_time.tv_sec * 1000))
2040
- ((intmax_t)waited_time.tv_nsec / 1000000));
2041
2042
if(debug){
2043
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
2044
block_time);
2045
}
2046
2047
if(block_time <= 0){
2048
ret = start_mandos_communication(mc->current_server->ip,
2049
mc->current_server->port,
2050
mc->current_server->if_index,
2051
mc->current_server->af, mc);
2052
if(ret == 0){
2053
avahi_simple_poll_quit(s);
2054
return 0;
2055
}
2056
ret = clock_gettime(CLOCK_MONOTONIC,
2057
&mc->current_server->last_seen);
2058
if(ret == -1){
2059
perror_plus("clock_gettime");
2060
return -1;
2061
}
2062
mc->current_server = mc->current_server->next;
2063
block_time = 0; /* Call avahi to find new Mandos
2064
servers, but don't block */
2065
}
2066
2067
ret = avahi_simple_poll_iterate(s, (int)block_time);
2068
}
2069
if(ret != 0){
2070
if(ret > 0 or errno != EINTR){
2071
return (ret != 1) ? ret : 0;
2072
}
2073
}
2074
}
2075
}
2076
2077
__attribute__((nonnull))
2078
void run_network_hooks(const char *mode, const char *interface,
2079
const float delay){
2080
struct dirent **direntries = NULL;
2081
if(hookdir_fd == -1){
2082
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
2083
| O_CLOEXEC);
2084
if(hookdir_fd == -1){
2085
if(errno == ENOENT){
2086
if(debug){
2087
fprintf_plus(stderr, "Network hook directory \"%s\" not"
2088
" found\n", hookdir);
2089
}
2090
} else {
2091
perror_plus("open");
2092
}
2093
return;
2094
}
2095
}
2096
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
2097
if(devnull == -1){
2098
perror_plus("open(\"/dev/null\", O_RDONLY)");
2099
return;
2100
}
2101
int numhooks = scandirat(hookdir_fd, ".", &direntries,
2102
runnable_hook, alphasort);
2103
if(numhooks == -1){
2104
perror_plus("scandir");
2105
close(devnull);
2106
return;
2107
}
2108
struct dirent *direntry;
2109
int ret;
2110
for(int i = 0; i < numhooks; i++){
2111
direntry = direntries[i];
2112
if(debug){
2113
fprintf_plus(stderr, "Running network hook \"%s\"\n",
2114
direntry->d_name);
2115
}
2116
pid_t hook_pid = fork();
2117
if(hook_pid == 0){
2118
/* Child */
2119
/* Raise privileges */
2120
errno = raise_privileges_permanently();
2121
if(errno != 0){
2122
perror_plus("Failed to raise privileges");
2123
_exit(EX_NOPERM);
2124
}
2125
/* Set group */
2126
errno = 0;
2127
ret = setgid(0);
2128
if(ret == -1){
2129
perror_plus("setgid");
2130
_exit(EX_NOPERM);
2131
}
2132
/* Reset supplementary groups */
2133
errno = 0;
2134
ret = setgroups(0, NULL);
2135
if(ret == -1){
2136
perror_plus("setgroups");
2137
_exit(EX_NOPERM);
2138
}
2139
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
2140
if(ret == -1){
2141
perror_plus("setenv");
2142
_exit(EX_OSERR);
2143
}
2144
ret = setenv("DEVICE", interface, 1);
2145
if(ret == -1){
2146
perror_plus("setenv");
2147
_exit(EX_OSERR);
2148
}
2149
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
2150
if(ret == -1){
2151
perror_plus("setenv");
2152
_exit(EX_OSERR);
2153
}
2154
ret = setenv("MODE", mode, 1);
2155
if(ret == -1){
2156
perror_plus("setenv");
2157
_exit(EX_OSERR);
2158
}
2159
char *delaystring;
2160
ret = asprintf(&delaystring, "%f", (double)delay);
2161
if(ret == -1){
2162
perror_plus("asprintf");
2163
_exit(EX_OSERR);
2164
}
2165
ret = setenv("DELAY", delaystring, 1);
2166
if(ret == -1){
2167
free(delaystring);
2168
perror_plus("setenv");
2169
_exit(EX_OSERR);
2170
}
2171
free(delaystring);
2172
if(connect_to != NULL){
2173
ret = setenv("CONNECT", connect_to, 1);
2174
if(ret == -1){
2175
perror_plus("setenv");
2176
_exit(EX_OSERR);
2177
}
2178
}
2179
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2180
direntry->d_name,
2181
O_RDONLY));
2182
if(hook_fd == -1){
2183
perror_plus("openat");
2184
_exit(EXIT_FAILURE);
2185
}
2186
if(close(hookdir_fd) == -1){
2187
perror_plus("close");
2188
_exit(EXIT_FAILURE);
2189
}
2190
ret = dup2(devnull, STDIN_FILENO);
2191
if(ret == -1){
2192
perror_plus("dup2(devnull, STDIN_FILENO)");
2193
_exit(EX_OSERR);
2194
}
2195
ret = close(devnull);
2196
if(ret == -1){
2197
perror_plus("close");
2198
_exit(EX_OSERR);
2199
}
2200
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2201
if(ret == -1){
2202
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2203
_exit(EX_OSERR);
2204
}
2205
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2206
environ) == -1){
2207
perror_plus("fexecve");
2208
_exit(EXIT_FAILURE);
2209
}
2210
} else {
2211
if(hook_pid == -1){
2212
perror_plus("fork");
2213
free(direntry);
2214
continue;
2215
}
2216
int status;
2217
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2218
perror_plus("waitpid");
2219
free(direntry);
2220
continue;
2221
}
2222
if(WIFEXITED(status)){
2223
if(WEXITSTATUS(status) != 0){
2224
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2225
" with status %d\n", direntry->d_name,
2226
WEXITSTATUS(status));
2227
free(direntry);
2228
continue;
2229
}
2230
} else if(WIFSIGNALED(status)){
2231
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2232
" signal %d\n", direntry->d_name,
2233
WTERMSIG(status));
2234
free(direntry);
2235
continue;
2236
} else {
2237
fprintf_plus(stderr, "Warning: network hook \"%s\""
2238
" crashed\n", direntry->d_name);
2239
free(direntry);
2240
continue;
2241
}
2242
}
2243
if(debug){
2244
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2245
direntry->d_name);
2246
}
2247
free(direntry);
2248
}
2249
free(direntries);
2250
if(close(hookdir_fd) == -1){
2251
perror_plus("close");
2252
} else {
2253
hookdir_fd = -1;
2254
}
2255
close(devnull);
2256
}
2257
2258
__attribute__((nonnull, warn_unused_result))
2259
int bring_up_interface(const char *const interface,
2260
const float delay){
2261
int old_errno = errno;
2262
int ret;
2263
struct ifreq network;
2264
unsigned int if_index = if_nametoindex(interface);
2265
if(if_index == 0){
2266
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2267
errno = old_errno;
2268
return ENXIO;
2269
}
2270
2271
if(quit_now){
2272
errno = old_errno;
2273
return EINTR;
2274
}
2275
2276
if(not interface_is_up(interface)){
2277
int ret_errno = 0;
2278
int ioctl_errno = 0;
2279
if(not get_flags(interface, &network)){
2280
ret_errno = errno;
2281
fprintf_plus(stderr, "Failed to get flags for interface "
2282
"\"%s\"\n", interface);
2283
errno = old_errno;
2284
return ret_errno;
2285
}
2286
network.ifr_flags |= IFF_UP; /* set flag */
2287
2288
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2289
if(sd == -1){
2290
ret_errno = errno;
2291
perror_plus("socket");
2292
errno = old_errno;
2293
return ret_errno;
2294
}
2295
2296
if(quit_now){
2297
ret = close(sd);
2298
if(ret == -1){
2299
perror_plus("close");
2300
}
2301
errno = old_errno;
2302
return EINTR;
2303
}
2304
2305
if(debug){
2306
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
2307
interface);
2308
}
2309
2310
/* Raise privileges */
2311
ret_errno = raise_privileges();
2312
if(ret_errno != 0){
2313
errno = ret_errno;
2314
perror_plus("Failed to raise privileges");
2315
}
2316
2317
#ifdef __linux__
2318
int ret_linux;
2319
bool restore_loglevel = false;
2320
if(ret_errno == 0){
2321
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
2322
messages about the network interface to mess up the prompt */
2323
ret_linux = klogctl(8, NULL, 5);
2324
if(ret_linux == -1){
2325
perror_plus("klogctl");
2326
} else {
2327
restore_loglevel = true;
2328
}
2329
}
2330
#endif /* __linux__ */
2331
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2332
ioctl_errno = errno;
2333
#ifdef __linux__
2334
if(restore_loglevel){
2335
ret_linux = klogctl(7, NULL, 0);
2336
if(ret_linux == -1){
2337
perror_plus("klogctl");
2338
}
2339
}
2340
#endif /* __linux__ */
2341
2342
/* If raise_privileges() succeeded above */
2343
if(ret_errno == 0){
2344
/* Lower privileges */
2345
ret_errno = lower_privileges();
2346
if(ret_errno != 0){
2347
errno = ret_errno;
2348
perror_plus("Failed to lower privileges");
2349
}
2350
}
2351
2352
/* Close the socket */
2353
ret = close(sd);
2354
if(ret == -1){
2355
perror_plus("close");
2356
}
2357
2358
if(ret_setflags == -1){
2359
errno = ioctl_errno;
2360
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2361
errno = old_errno;
2362
return ioctl_errno;
2363
}
2364
} else if(debug){
2365
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2366
interface);
2367
}
2368
2369
/* Sleep checking until interface is running.
2370
Check every 0.25s, up to total time of delay */
2371
for(int i = 0; i < delay * 4; i++){
2372
if(interface_is_running(interface)){
2373
break;
2374
}
2375
struct timespec sleeptime = { .tv_nsec = 250000000 };
2376
ret = nanosleep(&sleeptime, NULL);
2377
if(ret == -1 and errno != EINTR){
2378
perror_plus("nanosleep");
2379
}
2380
}
2381
2382
errno = old_errno;
2383
return 0;
2384
}
2385
2386
__attribute__((nonnull, warn_unused_result))
2387
int take_down_interface(const char *const interface){
2388
int old_errno = errno;
2389
struct ifreq network;
2390
unsigned int if_index = if_nametoindex(interface);
2391
if(if_index == 0){
2392
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2393
errno = old_errno;
2394
return ENXIO;
2395
}
2396
if(interface_is_up(interface)){
2397
int ret_errno = 0;
2398
int ioctl_errno = 0;
2399
if(not get_flags(interface, &network) and debug){
2400
ret_errno = errno;
2401
fprintf_plus(stderr, "Failed to get flags for interface "
2402
"\"%s\"\n", interface);
2403
errno = old_errno;
2404
return ret_errno;
2405
}
2406
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2407
2408
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2409
if(sd == -1){
2410
ret_errno = errno;
2411
perror_plus("socket");
2412
errno = old_errno;
2413
return ret_errno;
2414
}
2415
2416
if(debug){
2417
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2418
interface);
2419
}
2420
2421
/* Raise privileges */
2422
ret_errno = raise_privileges();
2423
if(ret_errno != 0){
2424
errno = ret_errno;
2425
perror_plus("Failed to raise privileges");
2426
}
2427
2428
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2429
ioctl_errno = errno;
2430
2431
/* If raise_privileges() succeeded above */
2432
if(ret_errno == 0){
2433
/* Lower privileges */
2434
ret_errno = lower_privileges();
2435
if(ret_errno != 0){
2436
errno = ret_errno;
2437
perror_plus("Failed to lower privileges");
2438
}
2439
}
2440
2441
/* Close the socket */
2442
int ret = close(sd);
2443
if(ret == -1){
2444
perror_plus("close");
2445
}
2446
2447
if(ret_setflags == -1){
2448
errno = ioctl_errno;
2449
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2450
errno = old_errno;
2451
return ioctl_errno;
2452
}
2453
} else if(debug){
2454
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
2455
interface);
2456
}
2457
2458
errno = old_errno;
2459
return 0;
2460
}
2461
2462
int main(int argc, char *argv[]){
2463
mandos_context mc = { .server = NULL, .dh_bits = 0,
2464
#if GNUTLS_VERSION_NUMBER >= 0x030606
2465
.priority = "SECURE128:!CTYPE-X.509"
2466
":+CTYPE-RAWPK:!RSA:!VERS-ALL:+VERS-TLS1.3"
2467
":%PROFILE_ULTRA",
2468
#elif GNUTLS_VERSION_NUMBER < 0x030600
2469
.priority = "SECURE256:!CTYPE-X.509"
2470
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2471
#else
2472
#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"
2473
#endif
2474
.current_server = NULL, .interfaces = NULL,
2475
.interfaces_size = 0 };
2476
AvahiSServiceBrowser *sb = NULL;
2477
error_t ret_errno;
2478
int ret;
2479
intmax_t tmpmax;
2480
char *tmp;
2481
int exitcode = EXIT_SUCCESS;
2482
char *interfaces_to_take_down = NULL;
2483
size_t interfaces_to_take_down_size = 0;
2484
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2485
char old_tempdir[] = "/tmp/mandosXXXXXX";
2486
char *tempdir = NULL;
2487
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2488
const char *seckey = PATHDIR "/" SECKEY;
2489
const char *pubkey = PATHDIR "/" PUBKEY;
2490
#if GNUTLS_VERSION_NUMBER >= 0x030606
2491
const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;
2492
const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;
2493
#endif
2494
const char *dh_params_file = NULL;
2495
char *interfaces_hooks = NULL;
2496
2497
bool gnutls_initialized = false;
2498
bool gpgme_initialized = false;
2499
float delay = 2.5f;
2500
double retry_interval = 10; /* 10s between trying a server and
2501
retrying the same server again */
2502
2503
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
2504
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
2505
2506
uid = getuid();
2507
gid = getgid();
2508
2509
/* Lower any group privileges we might have, just to be safe */
2510
errno = 0;
2511
ret = setgid(gid);
2512
if(ret == -1){
2513
perror_plus("setgid");
2514
}
2515
2516
/* Lower user privileges (temporarily) */
2517
errno = 0;
2518
ret = seteuid(uid);
2519
if(ret == -1){
2520
perror_plus("seteuid");
2521
}
2522
2523
if(quit_now){
2524
goto end;
2525
}
2526
2527
{
2528
struct argp_option options[] = {
2529
{ .name = "debug", .key = 128,
2530
.doc = "Debug mode", .group = 3 },
2531
{ .name = "connect", .key = 'c',
2532
.arg = "ADDRESS:PORT",
2533
.doc = "Connect directly to a specific Mandos server",
2534
.group = 1 },
2535
{ .name = "interface", .key = 'i',
2536
.arg = "NAME",
2537
.doc = "Network interface that will be used to search for"
2538
" Mandos servers",
2539
.group = 1 },
2540
{ .name = "seckey", .key = 's',
2541
.arg = "FILE",
2542
.doc = "OpenPGP secret key file base name",
2543
.group = 1 },
2544
{ .name = "pubkey", .key = 'p',
2545
.arg = "FILE",
2546
.doc = "OpenPGP public key file base name",
2547
.group = 1 },
2548
{ .name = "tls-privkey", .key = 't',
2549
.arg = "FILE",
2550
#if GNUTLS_VERSION_NUMBER >= 0x030606
2551
.doc = "TLS private key file base name",
2552
#else
2553
.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",
2554
#endif
2555
.group = 1 },
2556
{ .name = "tls-pubkey", .key = 'T',
2557
.arg = "FILE",
2558
#if GNUTLS_VERSION_NUMBER >= 0x030606
2559
.doc = "TLS public key file base name",
2560
#else
2561
.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",
2562
#endif
2563
.group = 1 },
2564
{ .name = "dh-bits", .key = 129,
2565
.arg = "BITS",
2566
.doc = "Bit length of the prime number used in the"
2567
" Diffie-Hellman key exchange",
2568
.group = 2 },
2569
{ .name = "dh-params", .key = 134,
2570
.arg = "FILE",
2571
.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"
2572
" for the Diffie-Hellman key exchange",
2573
.group = 2 },
2574
{ .name = "priority", .key = 130,
2575
.arg = "STRING",
2576
.doc = "GnuTLS priority string for the TLS handshake",
2577
.group = 1 },
2578
{ .name = "delay", .key = 131,
2579
.arg = "SECONDS",
2580
.doc = "Maximum delay to wait for interface startup",
2581
.group = 2 },
2582
{ .name = "retry", .key = 132,
2583
.arg = "SECONDS",
2584
.doc = "Retry interval used when denied by the Mandos server",
2585
.group = 2 },
2586
{ .name = "network-hook-dir", .key = 133,
2587
.arg = "DIR",
2588
.doc = "Directory where network hooks are located",
2589
.group = 2 },
2590
/*
2591
* These reproduce what we would get without ARGP_NO_HELP
2592
*/
2593
{ .name = "help", .key = '?',
2594
.doc = "Give this help list", .group = -1 },
2595
{ .name = "usage", .key = -3,
2596
.doc = "Give a short usage message", .group = -1 },
2597
{ .name = "version", .key = 'V',
2598
.doc = "Print program version", .group = -1 },
2599
{ .name = NULL }
2600
};
2601
2602
error_t parse_opt(int key, char *arg,
2603
struct argp_state *state){
2604
errno = 0;
2605
switch(key){
2606
case 128: /* --debug */
2607
debug = true;
2608
break;
2609
case 'c': /* --connect */
2610
connect_to = arg;
2611
break;
2612
case 'i': /* --interface */
2613
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2614
arg, (int)',');
2615
if(ret_errno != 0){
2616
argp_error(state, "%s", strerror(ret_errno));
2617
}
2618
break;
2619
case 's': /* --seckey */
2620
seckey = arg;
2621
break;
2622
case 'p': /* --pubkey */
2623
pubkey = arg;
2624
break;
2625
case 't': /* --tls-privkey */
2626
#if GNUTLS_VERSION_NUMBER >= 0x030606
2627
tls_privkey = arg;
2628
#endif
2629
break;
2630
case 'T': /* --tls-pubkey */
2631
#if GNUTLS_VERSION_NUMBER >= 0x030606
2632
tls_pubkey = arg;
2633
#endif
2634
break;
2635
case 129: /* --dh-bits */
2636
errno = 0;
2637
tmpmax = strtoimax(arg, &tmp, 10);
2638
if(errno != 0 or tmp == arg or *tmp != '\0'
2639
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2640
argp_error(state, "Bad number of DH bits");
2641
}
2642
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2643
break;
2644
case 134: /* --dh-params */
2645
dh_params_file = arg;
2646
break;
2647
case 130: /* --priority */
2648
mc.priority = arg;
2649
break;
2650
case 131: /* --delay */
2651
errno = 0;
2652
delay = strtof(arg, &tmp);
2653
if(errno != 0 or tmp == arg or *tmp != '\0'){
2654
argp_error(state, "Bad delay");
2655
}
2656
case 132: /* --retry */
2657
errno = 0;
2658
retry_interval = strtod(arg, &tmp);
2659
if(errno != 0 or tmp == arg or *tmp != '\0'
2660
or (retry_interval * 1000) > INT_MAX
2661
or retry_interval < 0){
2662
argp_error(state, "Bad retry interval");
2663
}
2664
break;
2665
case 133: /* --network-hook-dir */
2666
hookdir = arg;
2667
break;
2668
/*
2669
* These reproduce what we would get without ARGP_NO_HELP
2670
*/
2671
case '?': /* --help */
2672
argp_state_help(state, state->out_stream,
2673
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2674
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2675
__builtin_unreachable();
2676
case -3: /* --usage */
2677
argp_state_help(state, state->out_stream,
2678
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2679
__builtin_unreachable();
2680
case 'V': /* --version */
2681
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2682
exit(argp_err_exit_status);
2683
break;
2684
default:
2685
return ARGP_ERR_UNKNOWN;
2686
}
2687
return errno;
2688
}
2689
2690
struct argp argp = { .options = options, .parser = parse_opt,
2691
.args_doc = "",
2692
.doc = "Mandos client -- Get and decrypt"
2693
" passwords from a Mandos server" };
2694
ret_errno = argp_parse(&argp, argc, argv,
2695
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2696
switch(ret_errno){
2697
case 0:
2698
break;
2699
case ENOMEM:
2700
default:
2701
errno = ret_errno;
2702
perror_plus("argp_parse");
2703
exitcode = EX_OSERR;
2704
goto end;
2705
case EINVAL:
2706
exitcode = EX_USAGE;
2707
goto end;
2708
}
2709
}
2710
2711
{
2712
/* Work around Debian bug #633582:
2713
<https://bugs.debian.org/633582> */
2714
2715
/* Re-raise privileges */
2716
ret = raise_privileges();
2717
if(ret != 0){
2718
errno = ret;
2719
perror_plus("Failed to raise privileges");
2720
} else {
2721
struct stat st;
2722
2723
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2724
int seckey_fd = open(seckey, O_RDONLY);
2725
if(seckey_fd == -1){
2726
perror_plus("open");
2727
} else {
2728
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2729
if(ret == -1){
2730
perror_plus("fstat");
2731
} else {
2732
if(S_ISREG(st.st_mode)
2733
and st.st_uid == 0 and st.st_gid == 0){
2734
ret = fchown(seckey_fd, uid, gid);
2735
if(ret == -1){
2736
perror_plus("fchown");
2737
}
2738
}
2739
}
2740
close(seckey_fd);
2741
}
2742
}
2743
2744
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2745
int pubkey_fd = open(pubkey, O_RDONLY);
2746
if(pubkey_fd == -1){
2747
perror_plus("open");
2748
} else {
2749
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2750
if(ret == -1){
2751
perror_plus("fstat");
2752
} else {
2753
if(S_ISREG(st.st_mode)
2754
and st.st_uid == 0 and st.st_gid == 0){
2755
ret = fchown(pubkey_fd, uid, gid);
2756
if(ret == -1){
2757
perror_plus("fchown");
2758
}
2759
}
2760
}
2761
close(pubkey_fd);
2762
}
2763
}
2764
2765
if(dh_params_file != NULL
2766
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2767
int dhparams_fd = open(dh_params_file, O_RDONLY);
2768
if(dhparams_fd == -1){
2769
perror_plus("open");
2770
} else {
2771
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2772
if(ret == -1){
2773
perror_plus("fstat");
2774
} else {
2775
if(S_ISREG(st.st_mode)
2776
and st.st_uid == 0 and st.st_gid == 0){
2777
ret = fchown(dhparams_fd, uid, gid);
2778
if(ret == -1){
2779
perror_plus("fchown");
2780
}
2781
}
2782
}
2783
close(dhparams_fd);
2784
}
2785
}
2786
2787
/* Lower privileges */
2788
ret = lower_privileges();
2789
if(ret != 0){
2790
errno = ret;
2791
perror_plus("Failed to lower privileges");
2792
}
2793
}
2794
}
2795
2796
/* Remove invalid interface names (except "none") */
2797
{
2798
char *interface = NULL;
2799
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2800
interface))){
2801
if(strcmp(interface, "none") != 0
2802
and if_nametoindex(interface) == 0){
2803
if(interface[0] != '\0'){
2804
fprintf_plus(stderr, "Not using nonexisting interface"
2805
" \"%s\"\n", interface);
2806
}
2807
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2808
interface = NULL;
2809
}
2810
}
2811
}
2812
2813
/* Run network hooks */
2814
{
2815
if(mc.interfaces != NULL){
2816
interfaces_hooks = malloc(mc.interfaces_size);
2817
if(interfaces_hooks == NULL){
2818
perror_plus("malloc");
2819
goto end;
2820
}
2821
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2822
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2823
}
2824
run_network_hooks("start", interfaces_hooks != NULL ?
2825
interfaces_hooks : "", delay);
2826
}
2827
2828
if(not debug){
2829
avahi_set_log_function(empty_log);
2830
}
2831
2832
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2833
from the signal handler */
2834
/* Initialize the pseudo-RNG for Avahi */
2835
srand((unsigned int) time(NULL));
2836
simple_poll = avahi_simple_poll_new();
2837
if(simple_poll == NULL){
2838
fprintf_plus(stderr,
2839
"Avahi: Failed to create simple poll object.\n");
2840
exitcode = EX_UNAVAILABLE;
2841
goto end;
2842
}
2843
2844
sigemptyset(&sigterm_action.sa_mask);
2845
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2846
if(ret == -1){
2847
perror_plus("sigaddset");
2848
exitcode = EX_OSERR;
2849
goto end;
2850
}
2851
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2852
if(ret == -1){
2853
perror_plus("sigaddset");
2854
exitcode = EX_OSERR;
2855
goto end;
2856
}
2857
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2858
if(ret == -1){
2859
perror_plus("sigaddset");
2860
exitcode = EX_OSERR;
2861
goto end;
2862
}
2863
/* Need to check if the handler is SIG_IGN before handling:
2864
| [[info:libc:Initial Signal Actions]] |
2865
| [[info:libc:Basic Signal Handling]] |
2866
*/
2867
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2868
if(ret == -1){
2869
perror_plus("sigaction");
2870
return EX_OSERR;
2871
}
2872
if(old_sigterm_action.sa_handler != SIG_IGN){
2873
ret = sigaction(SIGINT, &sigterm_action, NULL);
2874
if(ret == -1){
2875
perror_plus("sigaction");
2876
exitcode = EX_OSERR;
2877
goto end;
2878
}
2879
}
2880
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2881
if(ret == -1){
2882
perror_plus("sigaction");
2883
return EX_OSERR;
2884
}
2885
if(old_sigterm_action.sa_handler != SIG_IGN){
2886
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2887
if(ret == -1){
2888
perror_plus("sigaction");
2889
exitcode = EX_OSERR;
2890
goto end;
2891
}
2892
}
2893
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2894
if(ret == -1){
2895
perror_plus("sigaction");
2896
return EX_OSERR;
2897
}
2898
if(old_sigterm_action.sa_handler != SIG_IGN){
2899
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2900
if(ret == -1){
2901
perror_plus("sigaction");
2902
exitcode = EX_OSERR;
2903
goto end;
2904
}
2905
}
2906
2907
/* If no interfaces were specified, make a list */
2908
if(mc.interfaces == NULL){
2909
struct dirent **direntries = NULL;
2910
/* Look for any good interfaces */
2911
ret = scandir(sys_class_net, &direntries, good_interface,
2912
alphasort);
2913
if(ret >= 1){
2914
/* Add all found interfaces to interfaces list */
2915
for(int i = 0; i < ret; ++i){
2916
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2917
direntries[i]->d_name);
2918
if(ret_errno != 0){
2919
errno = ret_errno;
2920
perror_plus("argz_add");
2921
free(direntries[i]);
2922
continue;
2923
}
2924
if(debug){
2925
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2926
direntries[i]->d_name);
2927
}
2928
free(direntries[i]);
2929
}
2930
free(direntries);
2931
} else {
2932
if(ret == 0){
2933
free(direntries);
2934
}
2935
fprintf_plus(stderr, "Could not find a network interface\n");
2936
exitcode = EXIT_FAILURE;
2937
goto end;
2938
}
2939
}
2940
2941
/* Bring up interfaces which are down, and remove any "none"s */
2942
{
2943
char *interface = NULL;
2944
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2945
interface))){
2946
/* If interface name is "none", stop bringing up interfaces.
2947
Also remove all instances of "none" from the list */
2948
if(strcmp(interface, "none") == 0){
2949
argz_delete(&mc.interfaces, &mc.interfaces_size,
2950
interface);
2951
interface = NULL;
2952
while((interface = argz_next(mc.interfaces,
2953
mc.interfaces_size, interface))){
2954
if(strcmp(interface, "none") == 0){
2955
argz_delete(&mc.interfaces, &mc.interfaces_size,
2956
interface);
2957
interface = NULL;
2958
}
2959
}
2960
break;
2961
}
2962
bool interface_was_up = interface_is_up(interface);
2963
errno = bring_up_interface(interface, delay);
2964
if(not interface_was_up){
2965
if(errno != 0){
2966
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2967
" %s\n", interface, strerror(errno));
2968
} else {
2969
errno = argz_add(&interfaces_to_take_down,
2970
&interfaces_to_take_down_size,
2971
interface);
2972
if(errno != 0){
2973
perror_plus("argz_add");
2974
}
2975
}
2976
}
2977
}
2978
if(debug and (interfaces_to_take_down == NULL)){
2979
fprintf_plus(stderr, "No interfaces were brought up\n");
2980
}
2981
}
2982
2983
/* If we only got one interface, explicitly use only that one */
2984
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2985
if(debug){
2986
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2987
mc.interfaces);
2988
}
2989
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2990
}
2991
2992
if(quit_now){
2993
goto end;
2994
}
2995
2996
#if GNUTLS_VERSION_NUMBER >= 0x030606
2997
ret = init_gnutls_global(tls_pubkey, tls_privkey, dh_params_file, &mc);
2998
#elif GNUTLS_VERSION_NUMBER < 0x030600
2999
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
3000
#else
3001
#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"
3002
#endif
3003
if(ret == -1){
3004
fprintf_plus(stderr, "init_gnutls_global failed\n");
3005
exitcode = EX_UNAVAILABLE;
3006
goto end;
3007
} else {
3008
gnutls_initialized = true;
3009
}
3010
3011
if(quit_now){
3012
goto end;
3013
}
3014
3015
/* Try /run/tmp before /tmp */
3016
tempdir = mkdtemp(run_tempdir);
3017
if(tempdir == NULL and errno == ENOENT){
3018
if(debug){
3019
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
3020
run_tempdir, old_tempdir);
3021
}
3022
tempdir = mkdtemp(old_tempdir);
3023
}
3024
if(tempdir == NULL){
3025
perror_plus("mkdtemp");
3026
goto end;
3027
}
3028
3029
if(quit_now){
3030
goto end;
3031
}
3032
3033
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
3034
fprintf_plus(stderr, "init_gpgme failed\n");
3035
exitcode = EX_UNAVAILABLE;
3036
goto end;
3037
} else {
3038
gpgme_initialized = true;
3039
}
3040
3041
if(quit_now){
3042
goto end;
3043
}
3044
3045
if(connect_to != NULL){
3046
/* Connect directly, do not use Zeroconf */
3047
/* (Mainly meant for debugging) */
3048
char *address = strrchr(connect_to, ':');
3049
3050
if(address == NULL){
3051
fprintf_plus(stderr, "No colon in address\n");
3052
exitcode = EX_USAGE;
3053
goto end;
3054
}
3055
3056
if(quit_now){
3057
goto end;
3058
}
3059
3060
in_port_t port;
3061
errno = 0;
3062
tmpmax = strtoimax(address+1, &tmp, 10);
3063
if(errno != 0 or tmp == address+1 or *tmp != '\0'
3064
or tmpmax != (in_port_t)tmpmax){
3065
fprintf_plus(stderr, "Bad port number\n");
3066
exitcode = EX_USAGE;
3067
goto end;
3068
}
3069
3070
if(quit_now){
3071
goto end;
3072
}
3073
3074
port = (in_port_t)tmpmax;
3075
*address = '\0';
3076
/* Colon in address indicates IPv6 */
3077
int af;
3078
if(strchr(connect_to, ':') != NULL){
3079
af = AF_INET6;
3080
/* Accept [] around IPv6 address - see RFC 5952 */
3081
if(connect_to[0] == '[' and address[-1] == ']')
3082
{
3083
connect_to++;
3084
address[-1] = '\0';
3085
}
3086
} else {
3087
af = AF_INET;
3088
}
3089
address = connect_to;
3090
3091
if(quit_now){
3092
goto end;
3093
}
3094
3095
while(not quit_now){
3096
ret = start_mandos_communication(address, port, if_index, af,
3097
&mc);
3098
if(quit_now or ret == 0){
3099
break;
3100
}
3101
if(debug){
3102
fprintf_plus(stderr, "Retrying in %d seconds\n",
3103
(int)retry_interval);
3104
}
3105
sleep((unsigned int)retry_interval);
3106
}
3107
3108
if(not quit_now){
3109
exitcode = EXIT_SUCCESS;
3110
}
3111
3112
goto end;
3113
}
3114
3115
if(quit_now){
3116
goto end;
3117
}
3118
3119
{
3120
AvahiServerConfig config;
3121
/* Do not publish any local Zeroconf records */
3122
avahi_server_config_init(&config);
3123
config.publish_hinfo = 0;
3124
config.publish_addresses = 0;
3125
config.publish_workstation = 0;
3126
config.publish_domain = 0;
3127
3128
/* Allocate a new server */
3129
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
3130
&config, NULL, NULL, &ret);
3131
3132
/* Free the Avahi configuration data */
3133
avahi_server_config_free(&config);
3134
}
3135
3136
/* Check if creating the Avahi server object succeeded */
3137
if(mc.server == NULL){
3138
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
3139
avahi_strerror(ret));
3140
exitcode = EX_UNAVAILABLE;
3141
goto end;
3142
}
3143
3144
if(quit_now){
3145
goto end;
3146
}
3147
3148
/* Create the Avahi service browser */
3149
sb = avahi_s_service_browser_new(mc.server, if_index,
3150
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
3151
NULL, 0, browse_callback,
3152
(void *)&mc);
3153
if(sb == NULL){
3154
fprintf_plus(stderr, "Failed to create service browser: %s\n",
3155
avahi_strerror(avahi_server_errno(mc.server)));
3156
exitcode = EX_UNAVAILABLE;
3157
goto end;
3158
}
3159
3160
if(quit_now){
3161
goto end;
3162
}
3163
3164
/* Run the main loop */
3165
3166
if(debug){
3167
fprintf_plus(stderr, "Starting Avahi loop search\n");
3168
}
3169
3170
ret = avahi_loop_with_timeout(simple_poll,
3171
(int)(retry_interval * 1000), &mc);
3172
if(debug){
3173
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
3174
(ret == 0) ? "successfully" : "with error");
3175
}
3176
3177
end:
3178
3179
if(debug){
3180
if(signal_received){
3181
fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",
3182
argv[0], signal_received,
3183
strsignal(signal_received));
3184
} else {
3185
fprintf_plus(stderr, "%s exiting\n", argv[0]);
3186
}
3187
}
3188
3189
/* Cleanup things */
3190
free(mc.interfaces);
3191
3192
if(sb != NULL)
3193
avahi_s_service_browser_free(sb);
3194
3195
if(mc.server != NULL)
3196
avahi_server_free(mc.server);
3197
3198
if(simple_poll != NULL)
3199
avahi_simple_poll_free(simple_poll);
3200
3201
if(gnutls_initialized){
3202
gnutls_certificate_free_credentials(mc.cred);
3203
gnutls_dh_params_deinit(mc.dh_params);
3204
}
3205
3206
if(gpgme_initialized){
3207
gpgme_release(mc.ctx);
3208
}
3209
3210
/* Cleans up the circular linked list of Mandos servers the client
3211
has seen */
3212
if(mc.current_server != NULL){
3213
mc.current_server->prev->next = NULL;
3214
while(mc.current_server != NULL){
3215
server *next = mc.current_server->next;
3216
#ifdef __GNUC__
3217
#pragma GCC diagnostic push
3218
#pragma GCC diagnostic ignored "-Wcast-qual"
3219
#endif
3220
free((char *)(mc.current_server->ip));
3221
#ifdef __GNUC__
3222
#pragma GCC diagnostic pop
3223
#endif
3224
free(mc.current_server);
3225
mc.current_server = next;
3226
}
3227
}
3228
3229
/* Re-raise privileges */
3230
{
3231
ret = raise_privileges();
3232
if(ret != 0){
3233
errno = ret;
3234
perror_plus("Failed to raise privileges");
3235
} else {
3236
3237
/* Run network hooks */
3238
run_network_hooks("stop", interfaces_hooks != NULL ?
3239
interfaces_hooks : "", delay);
3240
3241
/* Take down the network interfaces which were brought up */
3242
{
3243
char *interface = NULL;
3244
while((interface = argz_next(interfaces_to_take_down,
3245
interfaces_to_take_down_size,
3246
interface))){
3247
ret = take_down_interface(interface);
3248
if(ret != 0){
3249
errno = ret;
3250
perror_plus("Failed to take down interface");
3251
}
3252
}
3253
if(debug and (interfaces_to_take_down == NULL)){
3254
fprintf_plus(stderr, "No interfaces needed to be taken"
3255
" down\n");
3256
}
3257
}
3258
}
3259
3260
ret = lower_privileges_permanently();
3261
if(ret != 0){
3262
errno = ret;
3263
perror_plus("Failed to lower privileges permanently");
3264
}
3265
}
3266
3267
free(interfaces_to_take_down);
3268
free(interfaces_hooks);
3269
3270
void clean_dir_at(int base, const char * const dirname,
3271
uintmax_t level){
3272
struct dirent **direntries = NULL;
3273
int dret;
3274
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3275
O_RDONLY
3276
| O_NOFOLLOW
3277
| O_DIRECTORY
3278
| O_PATH));
3279
if(dir_fd == -1){
3280
perror_plus("open");
3281
return;
3282
}
3283
int numentries = scandirat(dir_fd, ".", &direntries,
3284
notdotentries, alphasort);
3285
if(numentries >= 0){
3286
for(int i = 0; i < numentries; i++){
3287
if(debug){
3288
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3289
dirname, direntries[i]->d_name);
3290
}
3291
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3292
if(dret == -1){
3293
if(errno == EISDIR){
3294
dret = unlinkat(dir_fd, direntries[i]->d_name,
3295
AT_REMOVEDIR);
3296
}
3297
if((dret == -1) and (errno == ENOTEMPTY)
3298
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3299
== 0) and (level == 0)){
3300
/* Recurse only in this special case */
3301
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3302
dret = 0;
3303
}
3304
if((dret == -1) and (errno != ENOENT)){
3305
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3306
direntries[i]->d_name, strerror(errno));
3307
}
3308
}
3309
free(direntries[i]);
3310
}
3311
3312
/* need to clean even if 0 because man page doesn't specify */
3313
free(direntries);
3314
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3315
if(dret == -1 and errno != ENOENT){
3316
perror_plus("rmdir");
3317
}
3318
} else {
3319
perror_plus("scandirat");
3320
}
3321
close(dir_fd);
3322
}
3323
3324
/* Removes the GPGME temp directory and all files inside */
3325
if(tempdir != NULL){
3326
clean_dir_at(-1, tempdir, 0);
3327
}
3328
3329
if(quit_now){
3330
sigemptyset(&old_sigterm_action.sa_mask);
3331
old_sigterm_action.sa_handler = SIG_DFL;
3332
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
3333
&old_sigterm_action,
3334
NULL));
3335
if(ret == -1){
3336
perror_plus("sigaction");
3337
}
3338
do {
3339
ret = raise(signal_received);
3340
} while(ret != 0 and errno == EINTR);
3341
if(ret != 0){
3342
perror_plus("raise");
3343
abort();
3344
}
3345
TEMP_FAILURE_RETRY(pause());
3346
}
3347
3348
return exitcode;
3349
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0