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- Committer: Björn Påhlsson
- Date: 2007-10-20 21:38:25 UTC
- Revision ID: belorn@tower-20071020213825-abf6f0d1c33ee961
First working version with: IPv6, GnuTLS, X.509 certificates, DN
retrieval.
retrieval.
- files added:
- bad-ca.pem
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- plugins.d
- 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 © 2008-2011 Teddy Hogeborn
13
* Copyright © 2008-2011 Björn Påhlsson
14
*
15
* This program is free software: you can redistribute it and/or
16
* modify it under the terms of the GNU General Public License as
17
* published by the Free Software Foundation, either version 3 of the
18
* License, or (at your option) any later version.
19
*
20
* This program is distributed in the hope that it will be useful, but
21
* WITHOUT ANY WARRANTY; without even the implied warranty of
22
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23
* General Public License for more details.
24
*
25
* You should have received a copy of the GNU General Public License
26
* along with this program. If not, see
27
* <http://www.gnu.org/licenses/>.
28
*
29
* Contact the authors at <mandos@recompile.se>.
30
*/
31
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
35
#endif
36
#ifndef _FILE_OFFSET_BITS
37
#define _FILE_OFFSET_BITS 64
38
#endif
39
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
41
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t */
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
strtof(), abort() */
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
55
opendir(), DIR */
56
#include <sys/stat.h> /* open() */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
61
*/
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
63
strtoimax() */
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
69
SIOCSIFFLAGS, if_indextoname(),
70
if_nametoindex(), IF_NAMESIZE */
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
*/
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
getuid(), getgid(), seteuid(),
76
setgid(), pause() */
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
78
#include <iso646.h> /* not, or, and */
79
#include <argp.h> /* struct argp_option, error_t, struct
80
argp_state, struct argp,
81
argp_parse(), ARGP_KEY_ARG,
82
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
85
raise() */
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
88
89
#ifdef __linux__
90
#include <sys/klog.h> /* klogctl() */
91
#endif /* __linux__ */
92
93
/* Avahi */
94
/* All Avahi types, constants and functions
95
Avahi*, avahi_*,
96
AVAHI_* */
97
#include <avahi-core/core.h>
98
#include <avahi-core/lookup.h>
99
#include <avahi-core/log.h>
100
#include <avahi-common/simple-watch.h>
101
#include <avahi-common/malloc.h>
102
#include <avahi-common/error.h>
103
104
/* GnuTLS */
105
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
106
functions:
107
gnutls_*
108
init_gnutls_session(),
109
GNUTLS_* */
110
#include <gnutls/openpgp.h>
111
/* gnutls_certificate_set_openpgp_key_file(),
112
GNUTLS_OPENPGP_FMT_BASE64 */
113
114
/* GPGME */
115
#include <gpgme.h> /* All GPGME types, constants and
116
functions:
117
gpgme_*
118
GPGME_PROTOCOL_OpenPGP,
119
GPG_ERR_NO_* */
120
121
#define BUFFER_SIZE 256
122
123
#define PATHDIR "/conf/conf.d/mandos"
124
#define SECKEY "seckey.txt"
125
#define PUBKEY "pubkey.txt"
126
127
bool debug = false;
128
static const char mandos_protocol_version[] = "1";
129
const char *argp_program_version = "mandos-client " VERSION;
130
const char *argp_program_bug_address = "<mandos@recompile.se>";
131
static const char sys_class_net[] = "/sys/class/net";
132
char *connect_to = NULL;
133
134
/* Doubly linked list that need to be circularly linked when used */
135
typedef struct server{
136
const char *ip;
137
uint16_t port;
138
AvahiIfIndex if_index;
139
int af;
140
struct timespec last_seen;
141
struct server *next;
142
struct server *prev;
143
} server;
144
145
/* Used for passing in values through the Avahi callback functions */
146
typedef struct {
147
AvahiSimplePoll *simple_poll;
148
AvahiServer *server;
149
gnutls_certificate_credentials_t cred;
150
unsigned int dh_bits;
151
gnutls_dh_params_t dh_params;
152
const char *priority;
153
gpgme_ctx_t ctx;
154
server *current_server;
155
} mandos_context;
156
157
/* global context so signal handler can reach it*/
158
mandos_context mc = { .simple_poll = NULL, .server = NULL,
159
.dh_bits = 1024, .priority = "SECURE256"
160
":!CTYPE-X.509:+CTYPE-OPENPGP",
161
.current_server = NULL };
162
163
sig_atomic_t quit_now = 0;
164
int signal_received = 0;
165
166
/* Function to use when printing errors */
167
void perror_plus(const char *print_text){
168
fprintf(stderr, "Mandos plugin %s: ",
169
program_invocation_short_name);
170
perror(print_text);
171
}
172
173
/*
174
* Make additional room in "buffer" for at least BUFFER_SIZE more
175
* bytes. "buffer_capacity" is how much is currently allocated,
176
* "buffer_length" is how much is already used.
177
*/
178
size_t incbuffer(char **buffer, size_t buffer_length,
179
size_t buffer_capacity){
180
if(buffer_length + BUFFER_SIZE > buffer_capacity){
181
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
182
if(buffer == NULL){
183
return 0;
184
}
185
buffer_capacity += BUFFER_SIZE;
186
}
187
return buffer_capacity;
188
}
189
190
/* Add server to set of servers to retry periodically */
191
int add_server(const char *ip, uint16_t port,
192
AvahiIfIndex if_index,
193
int af){
194
int ret;
195
server *new_server = malloc(sizeof(server));
196
if(new_server == NULL){
197
perror_plus("malloc");
198
return -1;
199
}
200
*new_server = (server){ .ip = strdup(ip),
201
.port = port,
202
.if_index = if_index,
203
.af = af };
204
if(new_server->ip == NULL){
205
perror_plus("strdup");
206
return -1;
207
}
208
/* Special case of first server */
209
if (mc.current_server == NULL){
210
new_server->next = new_server;
211
new_server->prev = new_server;
212
mc.current_server = new_server;
213
/* Place the new server last in the list */
214
} else {
215
new_server->next = mc.current_server;
216
new_server->prev = mc.current_server->prev;
217
new_server->prev->next = new_server;
218
mc.current_server->prev = new_server;
219
}
220
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
221
if(ret == -1){
222
perror_plus("clock_gettime");
223
return -1;
224
}
225
return 0;
226
}
227
228
/*
229
* Initialize GPGME.
230
*/
231
static bool init_gpgme(const char *seckey,
232
const char *pubkey, const char *tempdir){
233
gpgme_error_t rc;
234
gpgme_engine_info_t engine_info;
235
236
237
/*
238
* Helper function to insert pub and seckey to the engine keyring.
239
*/
240
bool import_key(const char *filename){
241
int ret;
242
int fd;
243
gpgme_data_t pgp_data;
244
245
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
246
if(fd == -1){
247
perror_plus("open");
248
return false;
249
}
250
251
rc = gpgme_data_new_from_fd(&pgp_data, fd);
252
if(rc != GPG_ERR_NO_ERROR){
253
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
254
gpgme_strsource(rc), gpgme_strerror(rc));
255
return false;
256
}
257
258
rc = gpgme_op_import(mc.ctx, pgp_data);
259
if(rc != GPG_ERR_NO_ERROR){
260
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
261
gpgme_strsource(rc), gpgme_strerror(rc));
262
return false;
263
}
264
265
ret = (int)TEMP_FAILURE_RETRY(close(fd));
266
if(ret == -1){
267
perror_plus("close");
268
}
269
gpgme_data_release(pgp_data);
270
return true;
271
}
272
273
if(debug){
274
fprintf(stderr, "Initializing GPGME\n");
275
}
276
277
/* Init GPGME */
278
gpgme_check_version(NULL);
279
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
280
if(rc != GPG_ERR_NO_ERROR){
281
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
282
gpgme_strsource(rc), gpgme_strerror(rc));
283
return false;
284
}
285
286
/* Set GPGME home directory for the OpenPGP engine only */
287
rc = gpgme_get_engine_info(&engine_info);
288
if(rc != GPG_ERR_NO_ERROR){
289
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
290
gpgme_strsource(rc), gpgme_strerror(rc));
291
return false;
292
}
293
while(engine_info != NULL){
294
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
295
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
296
engine_info->file_name, tempdir);
297
break;
298
}
299
engine_info = engine_info->next;
300
}
301
if(engine_info == NULL){
302
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
303
return false;
304
}
305
306
/* Create new GPGME "context" */
307
rc = gpgme_new(&(mc.ctx));
308
if(rc != GPG_ERR_NO_ERROR){
309
fprintf(stderr, "bad gpgme_new: %s: %s\n",
310
gpgme_strsource(rc), gpgme_strerror(rc));
311
return false;
312
}
313
314
if(not import_key(pubkey) or not import_key(seckey)){
315
return false;
316
}
317
318
return true;
319
}
320
321
/*
322
* Decrypt OpenPGP data.
323
* Returns -1 on error
324
*/
325
static ssize_t pgp_packet_decrypt(const char *cryptotext,
326
size_t crypto_size,
327
char **plaintext){
328
gpgme_data_t dh_crypto, dh_plain;
329
gpgme_error_t rc;
330
ssize_t ret;
331
size_t plaintext_capacity = 0;
332
ssize_t plaintext_length = 0;
333
334
if(debug){
335
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
336
}
337
338
/* Create new GPGME data buffer from memory cryptotext */
339
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
340
0);
341
if(rc != GPG_ERR_NO_ERROR){
342
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
343
gpgme_strsource(rc), gpgme_strerror(rc));
344
return -1;
345
}
346
347
/* Create new empty GPGME data buffer for the plaintext */
348
rc = gpgme_data_new(&dh_plain);
349
if(rc != GPG_ERR_NO_ERROR){
350
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
351
gpgme_strsource(rc), gpgme_strerror(rc));
352
gpgme_data_release(dh_crypto);
353
return -1;
354
}
355
356
/* Decrypt data from the cryptotext data buffer to the plaintext
357
data buffer */
358
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
359
if(rc != GPG_ERR_NO_ERROR){
360
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
361
gpgme_strsource(rc), gpgme_strerror(rc));
362
plaintext_length = -1;
363
if(debug){
364
gpgme_decrypt_result_t result;
365
result = gpgme_op_decrypt_result(mc.ctx);
366
if(result == NULL){
367
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
368
} else {
369
fprintf(stderr, "Unsupported algorithm: %s\n",
370
result->unsupported_algorithm);
371
fprintf(stderr, "Wrong key usage: %u\n",
372
result->wrong_key_usage);
373
if(result->file_name != NULL){
374
fprintf(stderr, "File name: %s\n", result->file_name);
375
}
376
gpgme_recipient_t recipient;
377
recipient = result->recipients;
378
while(recipient != NULL){
379
fprintf(stderr, "Public key algorithm: %s\n",
380
gpgme_pubkey_algo_name(recipient->pubkey_algo));
381
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
382
fprintf(stderr, "Secret key available: %s\n",
383
recipient->status == GPG_ERR_NO_SECKEY
384
? "No" : "Yes");
385
recipient = recipient->next;
386
}
387
}
388
}
389
goto decrypt_end;
390
}
391
392
if(debug){
393
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
394
}
395
396
/* Seek back to the beginning of the GPGME plaintext data buffer */
397
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
398
perror_plus("gpgme_data_seek");
399
plaintext_length = -1;
400
goto decrypt_end;
401
}
402
403
*plaintext = NULL;
404
while(true){
405
plaintext_capacity = incbuffer(plaintext,
406
(size_t)plaintext_length,
407
plaintext_capacity);
408
if(plaintext_capacity == 0){
409
perror_plus("incbuffer");
410
plaintext_length = -1;
411
goto decrypt_end;
412
}
413
414
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
415
BUFFER_SIZE);
416
/* Print the data, if any */
417
if(ret == 0){
418
/* EOF */
419
break;
420
}
421
if(ret < 0){
422
perror_plus("gpgme_data_read");
423
plaintext_length = -1;
424
goto decrypt_end;
425
}
426
plaintext_length += ret;
427
}
428
429
if(debug){
430
fprintf(stderr, "Decrypted password is: ");
431
for(ssize_t i = 0; i < plaintext_length; i++){
432
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
433
}
434
fprintf(stderr, "\n");
435
}
436
437
decrypt_end:
438
439
/* Delete the GPGME cryptotext data buffer */
440
gpgme_data_release(dh_crypto);
441
442
/* Delete the GPGME plaintext data buffer */
443
gpgme_data_release(dh_plain);
444
return plaintext_length;
445
}
446
447
static const char * safer_gnutls_strerror(int value){
448
const char *ret = gnutls_strerror(value); /* Spurious warning from
449
-Wunreachable-code */
450
if(ret == NULL)
451
ret = "(unknown)";
452
return ret;
453
}
454
455
/* GnuTLS log function callback */
456
static void debuggnutls(__attribute__((unused)) int level,
457
const char* string){
458
fprintf(stderr, "GnuTLS: %s", string);
459
}
460
461
static int init_gnutls_global(const char *pubkeyfilename,
462
const char *seckeyfilename){
463
int ret;
464
465
if(debug){
466
fprintf(stderr, "Initializing GnuTLS\n");
467
}
468
469
ret = gnutls_global_init();
470
if(ret != GNUTLS_E_SUCCESS){
471
fprintf(stderr, "GnuTLS global_init: %s\n",
472
safer_gnutls_strerror(ret));
473
return -1;
474
}
475
476
if(debug){
477
/* "Use a log level over 10 to enable all debugging options."
478
* - GnuTLS manual
479
*/
480
gnutls_global_set_log_level(11);
481
gnutls_global_set_log_function(debuggnutls);
482
}
483
484
/* OpenPGP credentials */
485
ret = gnutls_certificate_allocate_credentials(&mc.cred);
486
if(ret != GNUTLS_E_SUCCESS){
487
fprintf(stderr, "GnuTLS memory error: %s\n",
488
safer_gnutls_strerror(ret));
489
gnutls_global_deinit();
490
return -1;
491
}
492
493
if(debug){
494
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
495
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
496
seckeyfilename);
497
}
498
499
ret = gnutls_certificate_set_openpgp_key_file
500
(mc.cred, pubkeyfilename, seckeyfilename,
501
GNUTLS_OPENPGP_FMT_BASE64);
502
if(ret != GNUTLS_E_SUCCESS){
503
fprintf(stderr,
504
"Error[%d] while reading the OpenPGP key pair ('%s',"
505
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
506
fprintf(stderr, "The GnuTLS error is: %s\n",
507
safer_gnutls_strerror(ret));
508
goto globalfail;
509
}
510
511
/* GnuTLS server initialization */
512
ret = gnutls_dh_params_init(&mc.dh_params);
513
if(ret != GNUTLS_E_SUCCESS){
514
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
515
" %s\n", safer_gnutls_strerror(ret));
516
goto globalfail;
517
}
518
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
519
if(ret != GNUTLS_E_SUCCESS){
520
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
521
safer_gnutls_strerror(ret));
522
goto globalfail;
523
}
524
525
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
526
527
return 0;
528
529
globalfail:
530
531
gnutls_certificate_free_credentials(mc.cred);
532
gnutls_global_deinit();
533
gnutls_dh_params_deinit(mc.dh_params);
534
return -1;
535
}
536
537
static int init_gnutls_session(gnutls_session_t *session){
538
int ret;
539
/* GnuTLS session creation */
540
do {
541
ret = gnutls_init(session, GNUTLS_SERVER);
542
if(quit_now){
543
return -1;
544
}
545
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
546
if(ret != GNUTLS_E_SUCCESS){
547
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
548
safer_gnutls_strerror(ret));
549
}
550
551
{
552
const char *err;
553
do {
554
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
555
if(quit_now){
556
gnutls_deinit(*session);
557
return -1;
558
}
559
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
560
if(ret != GNUTLS_E_SUCCESS){
561
fprintf(stderr, "Syntax error at: %s\n", err);
562
fprintf(stderr, "GnuTLS error: %s\n",
563
safer_gnutls_strerror(ret));
564
gnutls_deinit(*session);
565
return -1;
566
}
567
}
568
569
do {
570
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
571
mc.cred);
572
if(quit_now){
573
gnutls_deinit(*session);
574
return -1;
575
}
576
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
577
if(ret != GNUTLS_E_SUCCESS){
578
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
579
safer_gnutls_strerror(ret));
580
gnutls_deinit(*session);
581
return -1;
582
}
583
584
/* ignore client certificate if any. */
585
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
586
587
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
588
589
return 0;
590
}
591
592
/* Avahi log function callback */
593
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
594
__attribute__((unused)) const char *txt){}
595
596
/* Called when a Mandos server is found */
597
static int start_mandos_communication(const char *ip, uint16_t port,
598
AvahiIfIndex if_index,
599
int af){
600
int ret, tcp_sd = -1;
601
ssize_t sret;
602
union {
603
struct sockaddr_in in;
604
struct sockaddr_in6 in6;
605
} to;
606
char *buffer = NULL;
607
char *decrypted_buffer = NULL;
608
size_t buffer_length = 0;
609
size_t buffer_capacity = 0;
610
size_t written;
611
int retval = -1;
612
gnutls_session_t session;
613
int pf; /* Protocol family */
614
615
errno = 0;
616
617
if(quit_now){
618
errno = EINTR;
619
return -1;
620
}
621
622
switch(af){
623
case AF_INET6:
624
pf = PF_INET6;
625
break;
626
case AF_INET:
627
pf = PF_INET;
628
break;
629
default:
630
fprintf(stderr, "Bad address family: %d\n", af);
631
errno = EINVAL;
632
return -1;
633
}
634
635
ret = init_gnutls_session(&session);
636
if(ret != 0){
637
return -1;
638
}
639
640
if(debug){
641
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
642
"\n", ip, port);
643
}
644
645
tcp_sd = socket(pf, SOCK_STREAM, 0);
646
if(tcp_sd < 0){
647
int e = errno;
648
perror_plus("socket");
649
errno = e;
650
goto mandos_end;
651
}
652
653
if(quit_now){
654
errno = EINTR;
655
goto mandos_end;
656
}
657
658
memset(&to, 0, sizeof(to));
659
if(af == AF_INET6){
660
to.in6.sin6_family = (sa_family_t)af;
661
ret = inet_pton(af, ip, &to.in6.sin6_addr);
662
} else { /* IPv4 */
663
to.in.sin_family = (sa_family_t)af;
664
ret = inet_pton(af, ip, &to.in.sin_addr);
665
}
666
if(ret < 0 ){
667
int e = errno;
668
perror_plus("inet_pton");
669
errno = e;
670
goto mandos_end;
671
}
672
if(ret == 0){
673
int e = errno;
674
fprintf(stderr, "Bad address: %s\n", ip);
675
errno = e;
676
goto mandos_end;
677
}
678
if(af == AF_INET6){
679
to.in6.sin6_port = htons(port); /* Spurious warnings from
680
-Wconversion and
681
-Wunreachable-code */
682
683
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
684
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
685
-Wunreachable-code*/
686
if(if_index == AVAHI_IF_UNSPEC){
687
fprintf(stderr, "An IPv6 link-local address is incomplete"
688
" without a network interface\n");
689
errno = EINVAL;
690
goto mandos_end;
691
}
692
/* Set the network interface number as scope */
693
to.in6.sin6_scope_id = (uint32_t)if_index;
694
}
695
} else {
696
to.in.sin_port = htons(port); /* Spurious warnings from
697
-Wconversion and
698
-Wunreachable-code */
699
}
700
701
if(quit_now){
702
errno = EINTR;
703
goto mandos_end;
704
}
705
706
if(debug){
707
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
708
char interface[IF_NAMESIZE];
709
if(if_indextoname((unsigned int)if_index, interface) == NULL){
710
perror_plus("if_indextoname");
711
} else {
712
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
713
ip, interface, port);
714
}
715
} else {
716
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
717
port);
718
}
719
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
720
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
721
const char *pcret;
722
if(af == AF_INET6){
723
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
724
sizeof(addrstr));
725
} else {
726
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
727
sizeof(addrstr));
728
}
729
if(pcret == NULL){
730
perror_plus("inet_ntop");
731
} else {
732
if(strcmp(addrstr, ip) != 0){
733
fprintf(stderr, "Canonical address form: %s\n", addrstr);
734
}
735
}
736
}
737
738
if(quit_now){
739
errno = EINTR;
740
goto mandos_end;
741
}
742
743
if(af == AF_INET6){
744
ret = connect(tcp_sd, &to.in6, sizeof(to));
745
} else {
746
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
747
}
748
if(ret < 0){
749
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
750
int e = errno;
751
perror_plus("connect");
752
errno = e;
753
}
754
goto mandos_end;
755
}
756
757
if(quit_now){
758
errno = EINTR;
759
goto mandos_end;
760
}
761
762
const char *out = mandos_protocol_version;
763
written = 0;
764
while(true){
765
size_t out_size = strlen(out);
766
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
767
out_size - written));
768
if(ret == -1){
769
int e = errno;
770
perror_plus("write");
771
errno = e;
772
goto mandos_end;
773
}
774
written += (size_t)ret;
775
if(written < out_size){
776
continue;
777
} else {
778
if(out == mandos_protocol_version){
779
written = 0;
780
out = "\r\n";
781
} else {
782
break;
783
}
784
}
785
786
if(quit_now){
787
errno = EINTR;
788
goto mandos_end;
789
}
790
}
791
792
if(debug){
793
fprintf(stderr, "Establishing TLS session with %s\n", ip);
794
}
795
796
if(quit_now){
797
errno = EINTR;
798
goto mandos_end;
799
}
800
801
/* Spurious warning from -Wint-to-pointer-cast */
802
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
803
804
if(quit_now){
805
errno = EINTR;
806
goto mandos_end;
807
}
808
809
do {
810
ret = gnutls_handshake(session);
811
if(quit_now){
812
errno = EINTR;
813
goto mandos_end;
814
}
815
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
816
817
if(ret != GNUTLS_E_SUCCESS){
818
if(debug){
819
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
820
gnutls_perror(ret);
821
}
822
errno = EPROTO;
823
goto mandos_end;
824
}
825
826
/* Read OpenPGP packet that contains the wanted password */
827
828
if(debug){
829
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
830
ip);
831
}
832
833
while(true){
834
835
if(quit_now){
836
errno = EINTR;
837
goto mandos_end;
838
}
839
840
buffer_capacity = incbuffer(&buffer, buffer_length,
841
buffer_capacity);
842
if(buffer_capacity == 0){
843
int e = errno;
844
perror_plus("incbuffer");
845
errno = e;
846
goto mandos_end;
847
}
848
849
if(quit_now){
850
errno = EINTR;
851
goto mandos_end;
852
}
853
854
sret = gnutls_record_recv(session, buffer+buffer_length,
855
BUFFER_SIZE);
856
if(sret == 0){
857
break;
858
}
859
if(sret < 0){
860
switch(sret){
861
case GNUTLS_E_INTERRUPTED:
862
case GNUTLS_E_AGAIN:
863
break;
864
case GNUTLS_E_REHANDSHAKE:
865
do {
866
ret = gnutls_handshake(session);
867
868
if(quit_now){
869
errno = EINTR;
870
goto mandos_end;
871
}
872
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
873
if(ret < 0){
874
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
875
gnutls_perror(ret);
876
errno = EPROTO;
877
goto mandos_end;
878
}
879
break;
880
default:
881
fprintf(stderr, "Unknown error while reading data from"
882
" encrypted session with Mandos server\n");
883
gnutls_bye(session, GNUTLS_SHUT_RDWR);
884
errno = EIO;
885
goto mandos_end;
886
}
887
} else {
888
buffer_length += (size_t) sret;
889
}
890
}
891
892
if(debug){
893
fprintf(stderr, "Closing TLS session\n");
894
}
895
896
if(quit_now){
897
errno = EINTR;
898
goto mandos_end;
899
}
900
901
do {
902
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
903
if(quit_now){
904
errno = EINTR;
905
goto mandos_end;
906
}
907
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
908
909
if(buffer_length > 0){
910
ssize_t decrypted_buffer_size;
911
decrypted_buffer_size = pgp_packet_decrypt(buffer,
912
buffer_length,
913
&decrypted_buffer);
914
if(decrypted_buffer_size >= 0){
915
916
written = 0;
917
while(written < (size_t) decrypted_buffer_size){
918
if(quit_now){
919
errno = EINTR;
920
goto mandos_end;
921
}
922
923
ret = (int)fwrite(decrypted_buffer + written, 1,
924
(size_t)decrypted_buffer_size - written,
925
stdout);
926
if(ret == 0 and ferror(stdout)){
927
int e = errno;
928
if(debug){
929
fprintf(stderr, "Error writing encrypted data: %s\n",
930
strerror(errno));
931
}
932
errno = e;
933
goto mandos_end;
934
}
935
written += (size_t)ret;
936
}
937
retval = 0;
938
}
939
}
940
941
/* Shutdown procedure */
942
943
mandos_end:
944
{
945
int e = errno;
946
free(decrypted_buffer);
947
free(buffer);
948
if(tcp_sd >= 0){
949
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
950
}
951
if(ret == -1){
952
if(e == 0){
953
e = errno;
954
}
955
perror_plus("close");
956
}
957
gnutls_deinit(session);
958
errno = e;
959
if(quit_now){
960
errno = EINTR;
961
retval = -1;
962
}
963
}
964
return retval;
965
}
966
967
static void resolve_callback(AvahiSServiceResolver *r,
968
AvahiIfIndex interface,
969
AvahiProtocol proto,
970
AvahiResolverEvent event,
971
const char *name,
972
const char *type,
973
const char *domain,
974
const char *host_name,
975
const AvahiAddress *address,
976
uint16_t port,
977
AVAHI_GCC_UNUSED AvahiStringList *txt,
978
AVAHI_GCC_UNUSED AvahiLookupResultFlags
979
flags,
980
AVAHI_GCC_UNUSED void* userdata){
981
assert(r);
982
983
/* Called whenever a service has been resolved successfully or
984
timed out */
985
986
if(quit_now){
987
return;
988
}
989
990
switch(event){
991
default:
992
case AVAHI_RESOLVER_FAILURE:
993
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
994
" of type '%s' in domain '%s': %s\n", name, type, domain,
995
avahi_strerror(avahi_server_errno(mc.server)));
996
break;
997
998
case AVAHI_RESOLVER_FOUND:
999
{
1000
char ip[AVAHI_ADDRESS_STR_MAX];
1001
avahi_address_snprint(ip, sizeof(ip), address);
1002
if(debug){
1003
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
1004
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
1005
ip, (intmax_t)interface, port);
1006
}
1007
int ret = start_mandos_communication(ip, port, interface,
1008
avahi_proto_to_af(proto));
1009
if(ret == 0){
1010
avahi_simple_poll_quit(mc.simple_poll);
1011
} else {
1012
ret = add_server(ip, port, interface,
1013
avahi_proto_to_af(proto));
1014
}
1015
}
1016
}
1017
avahi_s_service_resolver_free(r);
1018
}
1019
1020
static void browse_callback(AvahiSServiceBrowser *b,
1021
AvahiIfIndex interface,
1022
AvahiProtocol protocol,
1023
AvahiBrowserEvent event,
1024
const char *name,
1025
const char *type,
1026
const char *domain,
1027
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1028
flags,
1029
AVAHI_GCC_UNUSED void* userdata){
1030
assert(b);
1031
1032
/* Called whenever a new services becomes available on the LAN or
1033
is removed from the LAN */
1034
1035
if(quit_now){
1036
return;
1037
}
1038
1039
switch(event){
1040
default:
1041
case AVAHI_BROWSER_FAILURE:
1042
1043
fprintf(stderr, "(Avahi browser) %s\n",
1044
avahi_strerror(avahi_server_errno(mc.server)));
1045
avahi_simple_poll_quit(mc.simple_poll);
1046
return;
1047
1048
case AVAHI_BROWSER_NEW:
1049
/* We ignore the returned Avahi resolver object. In the callback
1050
function we free it. If the Avahi server is terminated before
1051
the callback function is called the Avahi server will free the
1052
resolver for us. */
1053
1054
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
1055
name, type, domain, protocol, 0,
1056
resolve_callback, NULL) == NULL)
1057
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
1058
name, avahi_strerror(avahi_server_errno(mc.server)));
1059
break;
1060
1061
case AVAHI_BROWSER_REMOVE:
1062
break;
1063
1064
case AVAHI_BROWSER_ALL_FOR_NOW:
1065
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1066
if(debug){
1067
fprintf(stderr, "No Mandos server found, still searching...\n");
1068
}
1069
break;
1070
}
1071
}
1072
1073
/* Signal handler that stops main loop after SIGTERM */
1074
static void handle_sigterm(int sig){
1075
if(quit_now){
1076
return;
1077
}
1078
quit_now = 1;
1079
signal_received = sig;
1080
int old_errno = errno;
1081
/* set main loop to exit */
1082
if(mc.simple_poll != NULL){
1083
avahi_simple_poll_quit(mc.simple_poll);
1084
}
1085
errno = old_errno;
1086
}
1087
1088
/*
1089
* This function determines if a directory entry in /sys/class/net
1090
* corresponds to an acceptable network device.
1091
* (This function is passed to scandir(3) as a filter function.)
1092
*/
1093
int good_interface(const struct dirent *if_entry){
1094
ssize_t ssret;
1095
char *flagname = NULL;
1096
if(if_entry->d_name[0] == '.'){
1097
return 0;
1098
}
1099
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1100
if_entry->d_name);
1101
if(ret < 0){
1102
perror_plus("asprintf");
1103
return 0;
1104
}
1105
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1106
if(flags_fd == -1){
1107
perror_plus("open");
1108
free(flagname);
1109
return 0;
1110
}
1111
free(flagname);
1112
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1113
/* read line from flags_fd */
1114
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1115
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1116
flagstring[(size_t)to_read] = '\0';
1117
if(flagstring == NULL){
1118
perror_plus("malloc");
1119
close(flags_fd);
1120
return 0;
1121
}
1122
while(to_read > 0){
1123
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1124
(size_t)to_read));
1125
if(ssret == -1){
1126
perror_plus("read");
1127
free(flagstring);
1128
close(flags_fd);
1129
return 0;
1130
}
1131
to_read -= ssret;
1132
if(ssret == 0){
1133
break;
1134
}
1135
}
1136
close(flags_fd);
1137
intmax_t tmpmax;
1138
char *tmp;
1139
errno = 0;
1140
tmpmax = strtoimax(flagstring, &tmp, 0);
1141
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1142
and not (isspace(*tmp)))
1143
or tmpmax != (ifreq_flags)tmpmax){
1144
if(debug){
1145
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1146
flagstring, if_entry->d_name);
1147
}
1148
free(flagstring);
1149
return 0;
1150
}
1151
free(flagstring);
1152
ifreq_flags flags = (ifreq_flags)tmpmax;
1153
/* Reject the loopback device */
1154
if(flags & IFF_LOOPBACK){
1155
if(debug){
1156
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1157
if_entry->d_name);
1158
}
1159
return 0;
1160
}
1161
/* Accept point-to-point devices only if connect_to is specified */
1162
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1163
if(debug){
1164
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1165
if_entry->d_name);
1166
}
1167
return 1;
1168
}
1169
/* Otherwise, reject non-broadcast-capable devices */
1170
if(not (flags & IFF_BROADCAST)){
1171
if(debug){
1172
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1173
if_entry->d_name);
1174
}
1175
return 0;
1176
}
1177
/* Reject non-ARP interfaces (including dummy interfaces) */
1178
if(flags & IFF_NOARP){
1179
if(debug){
1180
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1181
if_entry->d_name);
1182
}
1183
return 0;
1184
}
1185
/* Accept this device */
1186
if(debug){
1187
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1188
if_entry->d_name);
1189
}
1190
return 1;
1191
}
1192
1193
int notdotentries(const struct dirent *direntry){
1194
/* Skip "." and ".." */
1195
if(direntry->d_name[0] == '.'
1196
and (direntry->d_name[1] == '\0'
1197
or (direntry->d_name[1] == '.'
1198
and direntry->d_name[2] == '\0'))){
1199
return 0;
1200
}
1201
return 1;
1202
}
1203
1204
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1205
int ret;
1206
struct timespec now;
1207
struct timespec waited_time;
1208
intmax_t block_time;
1209
1210
while(true){
1211
if(mc.current_server == NULL){
1212
if (debug){
1213
fprintf(stderr,
1214
"Wait until first server is found. No timeout!\n");
1215
}
1216
ret = avahi_simple_poll_iterate(s, -1);
1217
} else {
1218
if (debug){
1219
fprintf(stderr, "Check current_server if we should run it,"
1220
" or wait\n");
1221
}
1222
/* the current time */
1223
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1224
if(ret == -1){
1225
perror_plus("clock_gettime");
1226
return -1;
1227
}
1228
/* Calculating in ms how long time between now and server
1229
who we visted longest time ago. Now - last seen. */
1230
waited_time.tv_sec = (now.tv_sec
1231
- mc.current_server->last_seen.tv_sec);
1232
waited_time.tv_nsec = (now.tv_nsec
1233
- mc.current_server->last_seen.tv_nsec);
1234
/* total time is 10s/10,000ms.
1235
Converting to s from ms by dividing by 1,000,
1236
and ns to ms by dividing by 1,000,000. */
1237
block_time = ((retry_interval
1238
- ((intmax_t)waited_time.tv_sec * 1000))
1239
- ((intmax_t)waited_time.tv_nsec / 1000000));
1240
1241
if (debug){
1242
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1243
}
1244
1245
if(block_time <= 0){
1246
ret = start_mandos_communication(mc.current_server->ip,
1247
mc.current_server->port,
1248
mc.current_server->if_index,
1249
mc.current_server->af);
1250
if(ret == 0){
1251
avahi_simple_poll_quit(mc.simple_poll);
1252
return 0;
1253
}
1254
ret = clock_gettime(CLOCK_MONOTONIC,
1255
&mc.current_server->last_seen);
1256
if(ret == -1){
1257
perror_plus("clock_gettime");
1258
return -1;
1259
}
1260
mc.current_server = mc.current_server->next;
1261
block_time = 0; /* Call avahi to find new Mandos
1262
servers, but don't block */
1263
}
1264
1265
ret = avahi_simple_poll_iterate(s, (int)block_time);
1266
}
1267
if(ret != 0){
1268
if (ret > 0 or errno != EINTR) {
1269
return (ret != 1) ? ret : 0;
1270
}
1271
}
1272
}
1273
}
1274
1275
int main(int argc, char *argv[]){
1276
AvahiSServiceBrowser *sb = NULL;
1277
int error;
1278
int ret;
1279
intmax_t tmpmax;
1280
char *tmp;
1281
int exitcode = EXIT_SUCCESS;
1282
const char *interface = "";
1283
struct ifreq network;
1284
int sd = -1;
1285
bool take_down_interface = false;
1286
uid_t uid;
1287
gid_t gid;
1288
char tempdir[] = "/tmp/mandosXXXXXX";
1289
bool tempdir_created = false;
1290
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1291
const char *seckey = PATHDIR "/" SECKEY;
1292
const char *pubkey = PATHDIR "/" PUBKEY;
1293
1294
bool gnutls_initialized = false;
1295
bool gpgme_initialized = false;
1296
float delay = 2.5f;
1297
double retry_interval = 10; /* 10s between trying a server and
1298
retrying the same server again */
1299
1300
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1301
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1302
1303
uid = getuid();
1304
gid = getgid();
1305
1306
/* Lower any group privileges we might have, just to be safe */
1307
errno = 0;
1308
ret = setgid(gid);
1309
if(ret == -1){
1310
perror_plus("setgid");
1311
}
1312
1313
/* Lower user privileges (temporarily) */
1314
errno = 0;
1315
ret = seteuid(uid);
1316
if(ret == -1){
1317
perror_plus("seteuid");
1318
}
1319
1320
if(quit_now){
1321
goto end;
1322
}
1323
1324
{
1325
struct argp_option options[] = {
1326
{ .name = "debug", .key = 128,
1327
.doc = "Debug mode", .group = 3 },
1328
{ .name = "connect", .key = 'c',
1329
.arg = "ADDRESS:PORT",
1330
.doc = "Connect directly to a specific Mandos server",
1331
.group = 1 },
1332
{ .name = "interface", .key = 'i',
1333
.arg = "NAME",
1334
.doc = "Network interface that will be used to search for"
1335
" Mandos servers",
1336
.group = 1 },
1337
{ .name = "seckey", .key = 's',
1338
.arg = "FILE",
1339
.doc = "OpenPGP secret key file base name",
1340
.group = 1 },
1341
{ .name = "pubkey", .key = 'p',
1342
.arg = "FILE",
1343
.doc = "OpenPGP public key file base name",
1344
.group = 2 },
1345
{ .name = "dh-bits", .key = 129,
1346
.arg = "BITS",
1347
.doc = "Bit length of the prime number used in the"
1348
" Diffie-Hellman key exchange",
1349
.group = 2 },
1350
{ .name = "priority", .key = 130,
1351
.arg = "STRING",
1352
.doc = "GnuTLS priority string for the TLS handshake",
1353
.group = 1 },
1354
{ .name = "delay", .key = 131,
1355
.arg = "SECONDS",
1356
.doc = "Maximum delay to wait for interface startup",
1357
.group = 2 },
1358
{ .name = "retry", .key = 132,
1359
.arg = "SECONDS",
1360
.doc = "Retry interval used when denied by the mandos server",
1361
.group = 2 },
1362
/*
1363
* These reproduce what we would get without ARGP_NO_HELP
1364
*/
1365
{ .name = "help", .key = '?',
1366
.doc = "Give this help list", .group = -1 },
1367
{ .name = "usage", .key = -3,
1368
.doc = "Give a short usage message", .group = -1 },
1369
{ .name = "version", .key = 'V',
1370
.doc = "Print program version", .group = -1 },
1371
{ .name = NULL }
1372
};
1373
1374
error_t parse_opt(int key, char *arg,
1375
struct argp_state *state){
1376
errno = 0;
1377
switch(key){
1378
case 128: /* --debug */
1379
debug = true;
1380
break;
1381
case 'c': /* --connect */
1382
connect_to = arg;
1383
break;
1384
case 'i': /* --interface */
1385
interface = arg;
1386
break;
1387
case 's': /* --seckey */
1388
seckey = arg;
1389
break;
1390
case 'p': /* --pubkey */
1391
pubkey = arg;
1392
break;
1393
case 129: /* --dh-bits */
1394
errno = 0;
1395
tmpmax = strtoimax(arg, &tmp, 10);
1396
if(errno != 0 or tmp == arg or *tmp != '\0'
1397
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1398
argp_error(state, "Bad number of DH bits");
1399
}
1400
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1401
break;
1402
case 130: /* --priority */
1403
mc.priority = arg;
1404
break;
1405
case 131: /* --delay */
1406
errno = 0;
1407
delay = strtof(arg, &tmp);
1408
if(errno != 0 or tmp == arg or *tmp != '\0'){
1409
argp_error(state, "Bad delay");
1410
}
1411
case 132: /* --retry */
1412
errno = 0;
1413
retry_interval = strtod(arg, &tmp);
1414
if(errno != 0 or tmp == arg or *tmp != '\0'
1415
or (retry_interval * 1000) > INT_MAX
1416
or retry_interval < 0){
1417
argp_error(state, "Bad retry interval");
1418
}
1419
break;
1420
/*
1421
* These reproduce what we would get without ARGP_NO_HELP
1422
*/
1423
case '?': /* --help */
1424
argp_state_help(state, state->out_stream,
1425
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1426
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1427
case -3: /* --usage */
1428
argp_state_help(state, state->out_stream,
1429
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1430
case 'V': /* --version */
1431
fprintf(state->out_stream, "%s\n", argp_program_version);
1432
exit(argp_err_exit_status);
1433
break;
1434
default:
1435
return ARGP_ERR_UNKNOWN;
1436
}
1437
return errno;
1438
}
1439
1440
struct argp argp = { .options = options, .parser = parse_opt,
1441
.args_doc = "",
1442
.doc = "Mandos client -- Get and decrypt"
1443
" passwords from a Mandos server" };
1444
ret = argp_parse(&argp, argc, argv,
1445
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1446
switch(ret){
1447
case 0:
1448
break;
1449
case ENOMEM:
1450
default:
1451
errno = ret;
1452
perror_plus("argp_parse");
1453
exitcode = EX_OSERR;
1454
goto end;
1455
case EINVAL:
1456
exitcode = EX_USAGE;
1457
goto end;
1458
}
1459
}
1460
1461
{
1462
/* Work around Debian bug #633582:
1463
<http://bugs.debian.org/633582> */
1464
struct stat st;
1465
1466
/* Re-raise priviliges */
1467
errno = 0;
1468
ret = seteuid(0);
1469
if(ret == -1){
1470
perror_plus("seteuid");
1471
}
1472
1473
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1474
int seckey_fd = open(seckey, O_RDONLY);
1475
if(seckey_fd == -1){
1476
perror_plus("open");
1477
} else {
1478
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1479
if(ret == -1){
1480
perror_plus("fstat");
1481
} else {
1482
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1483
ret = fchown(seckey_fd, uid, gid);
1484
if(ret == -1){
1485
perror_plus("fchown");
1486
}
1487
}
1488
}
1489
TEMP_FAILURE_RETRY(close(seckey_fd));
1490
}
1491
}
1492
1493
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1494
int pubkey_fd = open(pubkey, O_RDONLY);
1495
if(pubkey_fd == -1){
1496
perror_plus("open");
1497
} else {
1498
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1499
if(ret == -1){
1500
perror_plus("fstat");
1501
} else {
1502
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1503
ret = fchown(pubkey_fd, uid, gid);
1504
if(ret == -1){
1505
perror_plus("fchown");
1506
}
1507
}
1508
}
1509
TEMP_FAILURE_RETRY(close(pubkey_fd));
1510
}
1511
}
1512
1513
/* Lower privileges */
1514
errno = 0;
1515
ret = seteuid(uid);
1516
if(ret == -1){
1517
perror_plus("seteuid");
1518
}
1519
}
1520
1521
if(not debug){
1522
avahi_set_log_function(empty_log);
1523
}
1524
1525
if(interface[0] == '\0'){
1526
struct dirent **direntries;
1527
ret = scandir(sys_class_net, &direntries, good_interface,
1528
alphasort);
1529
if(ret >= 1){
1530
/* Pick the first good interface */
1531
interface = strdup(direntries[0]->d_name);
1532
if(debug){
1533
fprintf(stderr, "Using interface \"%s\"\n", interface);
1534
}
1535
if(interface == NULL){
1536
perror_plus("malloc");
1537
free(direntries);
1538
exitcode = EXIT_FAILURE;
1539
goto end;
1540
}
1541
free(direntries);
1542
} else {
1543
free(direntries);
1544
fprintf(stderr, "Could not find a network interface\n");
1545
exitcode = EXIT_FAILURE;
1546
goto end;
1547
}
1548
}
1549
1550
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1551
from the signal handler */
1552
/* Initialize the pseudo-RNG for Avahi */
1553
srand((unsigned int) time(NULL));
1554
mc.simple_poll = avahi_simple_poll_new();
1555
if(mc.simple_poll == NULL){
1556
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1557
exitcode = EX_UNAVAILABLE;
1558
goto end;
1559
}
1560
1561
sigemptyset(&sigterm_action.sa_mask);
1562
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1563
if(ret == -1){
1564
perror_plus("sigaddset");
1565
exitcode = EX_OSERR;
1566
goto end;
1567
}
1568
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1569
if(ret == -1){
1570
perror_plus("sigaddset");
1571
exitcode = EX_OSERR;
1572
goto end;
1573
}
1574
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1575
if(ret == -1){
1576
perror_plus("sigaddset");
1577
exitcode = EX_OSERR;
1578
goto end;
1579
}
1580
/* Need to check if the handler is SIG_IGN before handling:
1581
| [[info:libc:Initial Signal Actions]] |
1582
| [[info:libc:Basic Signal Handling]] |
1583
*/
1584
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1585
if(ret == -1){
1586
perror_plus("sigaction");
1587
return EX_OSERR;
1588
}
1589
if(old_sigterm_action.sa_handler != SIG_IGN){
1590
ret = sigaction(SIGINT, &sigterm_action, NULL);
1591
if(ret == -1){
1592
perror_plus("sigaction");
1593
exitcode = EX_OSERR;
1594
goto end;
1595
}
1596
}
1597
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1598
if(ret == -1){
1599
perror_plus("sigaction");
1600
return EX_OSERR;
1601
}
1602
if(old_sigterm_action.sa_handler != SIG_IGN){
1603
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1604
if(ret == -1){
1605
perror_plus("sigaction");
1606
exitcode = EX_OSERR;
1607
goto end;
1608
}
1609
}
1610
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1611
if(ret == -1){
1612
perror_plus("sigaction");
1613
return EX_OSERR;
1614
}
1615
if(old_sigterm_action.sa_handler != SIG_IGN){
1616
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1617
if(ret == -1){
1618
perror_plus("sigaction");
1619
exitcode = EX_OSERR;
1620
goto end;
1621
}
1622
}
1623
1624
/* If the interface is down, bring it up */
1625
if(strcmp(interface, "none") != 0){
1626
if_index = (AvahiIfIndex) if_nametoindex(interface);
1627
if(if_index == 0){
1628
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1629
exitcode = EX_UNAVAILABLE;
1630
goto end;
1631
}
1632
1633
if(quit_now){
1634
goto end;
1635
}
1636
1637
/* Re-raise priviliges */
1638
errno = 0;
1639
ret = seteuid(0);
1640
if(ret == -1){
1641
perror_plus("seteuid");
1642
}
1643
1644
#ifdef __linux__
1645
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1646
messages about the network interface to mess up the prompt */
1647
ret = klogctl(8, NULL, 5);
1648
bool restore_loglevel = true;
1649
if(ret == -1){
1650
restore_loglevel = false;
1651
perror_plus("klogctl");
1652
}
1653
#endif /* __linux__ */
1654
1655
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1656
if(sd < 0){
1657
perror_plus("socket");
1658
exitcode = EX_OSERR;
1659
#ifdef __linux__
1660
if(restore_loglevel){
1661
ret = klogctl(7, NULL, 0);
1662
if(ret == -1){
1663
perror_plus("klogctl");
1664
}
1665
}
1666
#endif /* __linux__ */
1667
/* Lower privileges */
1668
errno = 0;
1669
ret = seteuid(uid);
1670
if(ret == -1){
1671
perror_plus("seteuid");
1672
}
1673
goto end;
1674
}
1675
strcpy(network.ifr_name, interface);
1676
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1677
if(ret == -1){
1678
perror_plus("ioctl SIOCGIFFLAGS");
1679
#ifdef __linux__
1680
if(restore_loglevel){
1681
ret = klogctl(7, NULL, 0);
1682
if(ret == -1){
1683
perror_plus("klogctl");
1684
}
1685
}
1686
#endif /* __linux__ */
1687
exitcode = EX_OSERR;
1688
/* Lower privileges */
1689
errno = 0;
1690
ret = seteuid(uid);
1691
if(ret == -1){
1692
perror_plus("seteuid");
1693
}
1694
goto end;
1695
}
1696
if((network.ifr_flags & IFF_UP) == 0){
1697
network.ifr_flags |= IFF_UP;
1698
take_down_interface = true;
1699
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1700
if(ret == -1){
1701
take_down_interface = false;
1702
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1703
exitcode = EX_OSERR;
1704
#ifdef __linux__
1705
if(restore_loglevel){
1706
ret = klogctl(7, NULL, 0);
1707
if(ret == -1){
1708
perror_plus("klogctl");
1709
}
1710
}
1711
#endif /* __linux__ */
1712
/* Lower privileges */
1713
errno = 0;
1714
ret = seteuid(uid);
1715
if(ret == -1){
1716
perror_plus("seteuid");
1717
}
1718
goto end;
1719
}
1720
}
1721
/* Sleep checking until interface is running.
1722
Check every 0.25s, up to total time of delay */
1723
for(int i=0; i < delay * 4; i++){
1724
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1725
if(ret == -1){
1726
perror_plus("ioctl SIOCGIFFLAGS");
1727
} else if(network.ifr_flags & IFF_RUNNING){
1728
break;
1729
}
1730
struct timespec sleeptime = { .tv_nsec = 250000000 };
1731
ret = nanosleep(&sleeptime, NULL);
1732
if(ret == -1 and errno != EINTR){
1733
perror_plus("nanosleep");
1734
}
1735
}
1736
if(not take_down_interface){
1737
/* We won't need the socket anymore */
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1739
if(ret == -1){
1740
perror_plus("close");
1741
}
1742
}
1743
#ifdef __linux__
1744
if(restore_loglevel){
1745
/* Restores kernel loglevel to default */
1746
ret = klogctl(7, NULL, 0);
1747
if(ret == -1){
1748
perror_plus("klogctl");
1749
}
1750
}
1751
#endif /* __linux__ */
1752
/* Lower privileges */
1753
errno = 0;
1754
if(take_down_interface){
1755
/* Lower privileges */
1756
ret = seteuid(uid);
1757
if(ret == -1){
1758
perror_plus("seteuid");
1759
}
1760
} else {
1761
/* Lower privileges permanently */
1762
ret = setuid(uid);
1763
if(ret == -1){
1764
perror_plus("setuid");
1765
}
1766
}
1767
}
1768
1769
if(quit_now){
1770
goto end;
1771
}
1772
1773
ret = init_gnutls_global(pubkey, seckey);
1774
if(ret == -1){
1775
fprintf(stderr, "init_gnutls_global failed\n");
1776
exitcode = EX_UNAVAILABLE;
1777
goto end;
1778
} else {
1779
gnutls_initialized = true;
1780
}
1781
1782
if(quit_now){
1783
goto end;
1784
}
1785
1786
if(mkdtemp(tempdir) == NULL){
1787
perror_plus("mkdtemp");
1788
goto end;
1789
}
1790
tempdir_created = true;
1791
1792
if(quit_now){
1793
goto end;
1794
}
1795
1796
if(not init_gpgme(pubkey, seckey, tempdir)){
1797
fprintf(stderr, "init_gpgme failed\n");
1798
exitcode = EX_UNAVAILABLE;
1799
goto end;
1800
} else {
1801
gpgme_initialized = true;
1802
}
1803
1804
if(quit_now){
1805
goto end;
1806
}
1807
1808
if(connect_to != NULL){
1809
/* Connect directly, do not use Zeroconf */
1810
/* (Mainly meant for debugging) */
1811
char *address = strrchr(connect_to, ':');
1812
if(address == NULL){
1813
fprintf(stderr, "No colon in address\n");
1814
exitcode = EX_USAGE;
1815
goto end;
1816
}
1817
1818
if(quit_now){
1819
goto end;
1820
}
1821
1822
uint16_t port;
1823
errno = 0;
1824
tmpmax = strtoimax(address+1, &tmp, 10);
1825
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1826
or tmpmax != (uint16_t)tmpmax){
1827
fprintf(stderr, "Bad port number\n");
1828
exitcode = EX_USAGE;
1829
goto end;
1830
}
1831
1832
if(quit_now){
1833
goto end;
1834
}
1835
1836
port = (uint16_t)tmpmax;
1837
*address = '\0';
1838
/* Colon in address indicates IPv6 */
1839
int af;
1840
if(strchr(connect_to, ':') != NULL){
1841
af = AF_INET6;
1842
/* Accept [] around IPv6 address - see RFC 5952 */
1843
if(connect_to[0] == '[' and address[-1] == ']')
1844
{
1845
connect_to++;
1846
address[-1] = '\0';
1847
}
1848
} else {
1849
af = AF_INET;
1850
}
1851
address = connect_to;
1852
1853
if(quit_now){
1854
goto end;
1855
}
1856
1857
while(not quit_now){
1858
ret = start_mandos_communication(address, port, if_index, af);
1859
if(quit_now or ret == 0){
1860
break;
1861
}
1862
if(debug){
1863
fprintf(stderr, "Retrying in %d seconds\n",
1864
(int)retry_interval);
1865
}
1866
sleep((int)retry_interval);
1867
}
1868
1869
if (not quit_now){
1870
exitcode = EXIT_SUCCESS;
1871
}
1872
1873
goto end;
1874
}
1875
1876
if(quit_now){
1877
goto end;
1878
}
1879
1880
{
1881
AvahiServerConfig config;
1882
/* Do not publish any local Zeroconf records */
1883
avahi_server_config_init(&config);
1884
config.publish_hinfo = 0;
1885
config.publish_addresses = 0;
1886
config.publish_workstation = 0;
1887
config.publish_domain = 0;
1888
1889
/* Allocate a new server */
1890
mc.server = avahi_server_new(avahi_simple_poll_get
1891
(mc.simple_poll), &config, NULL,
1892
NULL, &error);
1893
1894
/* Free the Avahi configuration data */
1895
avahi_server_config_free(&config);
1896
}
1897
1898
/* Check if creating the Avahi server object succeeded */
1899
if(mc.server == NULL){
1900
fprintf(stderr, "Failed to create Avahi server: %s\n",
1901
avahi_strerror(error));
1902
exitcode = EX_UNAVAILABLE;
1903
goto end;
1904
}
1905
1906
if(quit_now){
1907
goto end;
1908
}
1909
1910
/* Create the Avahi service browser */
1911
sb = avahi_s_service_browser_new(mc.server, if_index,
1912
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1913
NULL, 0, browse_callback, NULL);
1914
if(sb == NULL){
1915
fprintf(stderr, "Failed to create service browser: %s\n",
1916
avahi_strerror(avahi_server_errno(mc.server)));
1917
exitcode = EX_UNAVAILABLE;
1918
goto end;
1919
}
1920
1921
if(quit_now){
1922
goto end;
1923
}
1924
1925
/* Run the main loop */
1926
1927
if(debug){
1928
fprintf(stderr, "Starting Avahi loop search\n");
1929
}
1930
1931
ret = avahi_loop_with_timeout(mc.simple_poll,
1932
(int)(retry_interval * 1000));
1933
if(debug){
1934
fprintf(stderr, "avahi_loop_with_timeout exited %s\n",
1935
(ret == 0) ? "successfully" : "with error");
1936
}
1937
1938
end:
1939
1940
if(debug){
1941
fprintf(stderr, "%s exiting\n", argv[0]);
1942
}
1943
1944
/* Cleanup things */
1945
if(sb != NULL)
1946
avahi_s_service_browser_free(sb);
1947
1948
if(mc.server != NULL)
1949
avahi_server_free(mc.server);
1950
1951
if(mc.simple_poll != NULL)
1952
avahi_simple_poll_free(mc.simple_poll);
1953
1954
if(gnutls_initialized){
1955
gnutls_certificate_free_credentials(mc.cred);
1956
gnutls_global_deinit();
1957
gnutls_dh_params_deinit(mc.dh_params);
1958
}
1959
1960
if(gpgme_initialized){
1961
gpgme_release(mc.ctx);
1962
}
1963
1964
/* Cleans up the circular linked list of Mandos servers the client
1965
has seen */
1966
if(mc.current_server != NULL){
1967
mc.current_server->prev->next = NULL;
1968
while(mc.current_server != NULL){
1969
server *next = mc.current_server->next;
1970
free(mc.current_server);
1971
mc.current_server = next;
1972
}
1973
}
1974
1975
/* Take down the network interface */
1976
if(take_down_interface){
1977
/* Re-raise priviliges */
1978
errno = 0;
1979
ret = seteuid(0);
1980
if(ret == -1){
1981
perror_plus("seteuid");
1982
}
1983
if(geteuid() == 0){
1984
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1985
if(ret == -1){
1986
perror_plus("ioctl SIOCGIFFLAGS");
1987
} else if(network.ifr_flags & IFF_UP) {
1988
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1989
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1990
if(ret == -1){
1991
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1992
}
1993
}
1994
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1995
if(ret == -1){
1996
perror_plus("close");
1997
}
1998
/* Lower privileges permanently */
1999
errno = 0;
2000
ret = setuid(uid);
2001
if(ret == -1){
2002
perror_plus("setuid");
2003
}
2004
}
2005
}
2006
2007
/* Removes the GPGME temp directory and all files inside */
2008
if(tempdir_created){
2009
struct dirent **direntries = NULL;
2010
struct dirent *direntry = NULL;
2011
int numentries = scandir(tempdir, &direntries, notdotentries,
2012
alphasort);
2013
if (numentries > 0){
2014
for(int i = 0; i < numentries; i++){
2015
direntry = direntries[i];
2016
char *fullname = NULL;
2017
ret = asprintf(&fullname, "%s/%s", tempdir,
2018
direntry->d_name);
2019
if(ret < 0){
2020
perror_plus("asprintf");
2021
continue;
2022
}
2023
ret = remove(fullname);
2024
if(ret == -1){
2025
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
2026
strerror(errno));
2027
}
2028
free(fullname);
2029
}
2030
}
2031
2032
/* need to clean even if 0 because man page doesn't specify */
2033
free(direntries);
2034
if (numentries == -1){
2035
perror_plus("scandir");
2036
}
2037
ret = rmdir(tempdir);
2038
if(ret == -1 and errno != ENOENT){
2039
perror_plus("rmdir");
2040
}
2041
}
2042
2043
if(quit_now){
2044
sigemptyset(&old_sigterm_action.sa_mask);
2045
old_sigterm_action.sa_handler = SIG_DFL;
2046
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2047
&old_sigterm_action,
2048
NULL));
2049
if(ret == -1){
2050
perror_plus("sigaction");
2051
}
2052
do {
2053
ret = raise(signal_received);
2054
} while(ret != 0 and errno == EINTR);
2055
if(ret != 0){
2056
perror_plus("raise");
2057
abort();
2058
}
2059
TEMP_FAILURE_RETRY(pause());
2060
}
2061
2062
return exitcode;
2063
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0