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