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