To get this branch, use:
bzr branch
http://bzr.recompile.se/loggerhead/mandos/trunk
« back to all changes in this revision
Viewing changes to plugins.d/mandos-client.c
- browse files at revision 1
- compare with another revision
- download diff
- download tarball
- view history from revision 1
- 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
- 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 © 2008,2009 Teddy Hogeborn
13
* Copyright © 2008,2009 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
#define _LARGEFILE_SOURCE
34
#define _FILE_OFFSET_BITS 64
35
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
37
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), remove() */
40
#include <stdint.h> /* uint16_t, uint32_t */
41
#include <stddef.h> /* NULL, size_t, ssize_t */
42
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
srand(), strtof() */
44
#include <stdbool.h> /* bool, false, true */
45
#include <string.h> /* memset(), strcmp(), strlen(),
46
strerror(), asprintf(), strcpy() */
47
#include <sys/ioctl.h> /* ioctl */
48
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
49
sockaddr_in6, PF_INET6,
50
SOCK_STREAM, uid_t, gid_t, open(),
51
opendir(), DIR */
52
#include <sys/stat.h> /* open() */
53
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
54
inet_pton(), connect() */
55
#include <fcntl.h> /* open() */
56
#include <dirent.h> /* opendir(), struct dirent, readdir()
57
*/
58
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
59
strtoimax() */
60
#include <assert.h> /* assert() */
61
#include <errno.h> /* perror(), errno */
62
#include <time.h> /* nanosleep(), time() */
63
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
64
SIOCSIFFLAGS, if_indextoname(),
65
if_nametoindex(), IF_NAMESIZE */
66
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
68
*/
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
getuid(), getgid(), setuid(),
71
setgid() */
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, or, and */
74
#include <argp.h> /* struct argp_option, error_t, struct
75
argp_state, struct argp,
76
argp_parse(), ARGP_KEY_ARG,
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
78
#include <signal.h> /* sigemptyset(), sigaddset(),
79
sigaction(), SIGTERM, sigaction,
80
sig_atomic_t */
81
82
#ifdef __linux__
83
#include <sys/klog.h> /* klogctl() */
84
#endif /* __linux__ */
85
86
/* Avahi */
87
/* All Avahi types, constants and functions
88
Avahi*, avahi_*,
89
AVAHI_* */
90
#include <avahi-core/core.h>
91
#include <avahi-core/lookup.h>
92
#include <avahi-core/log.h>
93
#include <avahi-common/simple-watch.h>
94
#include <avahi-common/malloc.h>
95
#include <avahi-common/error.h>
96
97
/* GnuTLS */
98
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
99
functions:
100
gnutls_*
101
init_gnutls_session(),
102
GNUTLS_* */
103
#include <gnutls/openpgp.h>
104
/* gnutls_certificate_set_openpgp_key_file(),
105
GNUTLS_OPENPGP_FMT_BASE64 */
106
107
/* GPGME */
108
#include <gpgme.h> /* All GPGME types, constants and
109
functions:
110
gpgme_*
111
GPGME_PROTOCOL_OpenPGP,
112
GPG_ERR_NO_* */
113
114
#define BUFFER_SIZE 256
115
116
#define PATHDIR "/conf/conf.d/mandos"
117
#define SECKEY "seckey.txt"
118
#define PUBKEY "pubkey.txt"
119
120
bool debug = false;
121
static const char mandos_protocol_version[] = "1";
122
const char *argp_program_version = "mandos-client " VERSION;
123
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
124
125
/* Used for passing in values through the Avahi callback functions */
126
typedef struct {
127
AvahiSimplePoll *simple_poll;
128
AvahiServer *server;
129
gnutls_certificate_credentials_t cred;
130
unsigned int dh_bits;
131
gnutls_dh_params_t dh_params;
132
const char *priority;
133
gpgme_ctx_t ctx;
134
} mandos_context;
135
136
/* global context so signal handler can reach it*/
137
mandos_context mc = { .simple_poll = NULL, .server = NULL,
138
.dh_bits = 1024, .priority = "SECURE256"
139
":!CTYPE-X.509:+CTYPE-OPENPGP" };
140
141
/*
142
* Make additional room in "buffer" for at least BUFFER_SIZE more
143
* bytes. "buffer_capacity" is how much is currently allocated,
144
* "buffer_length" is how much is already used.
145
*/
146
size_t incbuffer(char **buffer, size_t buffer_length,
147
size_t buffer_capacity){
148
if(buffer_length + BUFFER_SIZE > buffer_capacity){
149
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
150
if(buffer == NULL){
151
return 0;
152
}
153
buffer_capacity += BUFFER_SIZE;
154
}
155
return buffer_capacity;
156
}
157
158
/*
159
* Initialize GPGME.
160
*/
161
static bool init_gpgme(const char *seckey,
162
const char *pubkey, const char *tempdir){
163
int ret;
164
gpgme_error_t rc;
165
gpgme_engine_info_t engine_info;
166
167
168
/*
169
* Helper function to insert pub and seckey to the engine keyring.
170
*/
171
bool import_key(const char *filename){
172
int fd;
173
gpgme_data_t pgp_data;
174
175
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
176
if(fd == -1){
177
perror("open");
178
return false;
179
}
180
181
rc = gpgme_data_new_from_fd(&pgp_data, fd);
182
if(rc != GPG_ERR_NO_ERROR){
183
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
184
gpgme_strsource(rc), gpgme_strerror(rc));
185
return false;
186
}
187
188
rc = gpgme_op_import(mc.ctx, pgp_data);
189
if(rc != GPG_ERR_NO_ERROR){
190
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
191
gpgme_strsource(rc), gpgme_strerror(rc));
192
return false;
193
}
194
195
ret = (int)TEMP_FAILURE_RETRY(close(fd));
196
if(ret == -1){
197
perror("close");
198
}
199
gpgme_data_release(pgp_data);
200
return true;
201
}
202
203
if(debug){
204
fprintf(stderr, "Initializing GPGME\n");
205
}
206
207
/* Init GPGME */
208
gpgme_check_version(NULL);
209
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
210
if(rc != GPG_ERR_NO_ERROR){
211
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
212
gpgme_strsource(rc), gpgme_strerror(rc));
213
return false;
214
}
215
216
/* Set GPGME home directory for the OpenPGP engine only */
217
rc = gpgme_get_engine_info(&engine_info);
218
if(rc != GPG_ERR_NO_ERROR){
219
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
220
gpgme_strsource(rc), gpgme_strerror(rc));
221
return false;
222
}
223
while(engine_info != NULL){
224
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
225
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
226
engine_info->file_name, tempdir);
227
break;
228
}
229
engine_info = engine_info->next;
230
}
231
if(engine_info == NULL){
232
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
233
return false;
234
}
235
236
/* Create new GPGME "context" */
237
rc = gpgme_new(&(mc.ctx));
238
if(rc != GPG_ERR_NO_ERROR){
239
fprintf(stderr, "bad gpgme_new: %s: %s\n",
240
gpgme_strsource(rc), gpgme_strerror(rc));
241
return false;
242
}
243
244
if(not import_key(pubkey) or not import_key(seckey)){
245
return false;
246
}
247
248
return true;
249
}
250
251
/*
252
* Decrypt OpenPGP data.
253
* Returns -1 on error
254
*/
255
static ssize_t pgp_packet_decrypt(const char *cryptotext,
256
size_t crypto_size,
257
char **plaintext){
258
gpgme_data_t dh_crypto, dh_plain;
259
gpgme_error_t rc;
260
ssize_t ret;
261
size_t plaintext_capacity = 0;
262
ssize_t plaintext_length = 0;
263
264
if(debug){
265
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
266
}
267
268
/* Create new GPGME data buffer from memory cryptotext */
269
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
270
0);
271
if(rc != GPG_ERR_NO_ERROR){
272
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
273
gpgme_strsource(rc), gpgme_strerror(rc));
274
return -1;
275
}
276
277
/* Create new empty GPGME data buffer for the plaintext */
278
rc = gpgme_data_new(&dh_plain);
279
if(rc != GPG_ERR_NO_ERROR){
280
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
281
gpgme_strsource(rc), gpgme_strerror(rc));
282
gpgme_data_release(dh_crypto);
283
return -1;
284
}
285
286
/* Decrypt data from the cryptotext data buffer to the plaintext
287
data buffer */
288
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
289
if(rc != GPG_ERR_NO_ERROR){
290
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
291
gpgme_strsource(rc), gpgme_strerror(rc));
292
plaintext_length = -1;
293
if(debug){
294
gpgme_decrypt_result_t result;
295
result = gpgme_op_decrypt_result(mc.ctx);
296
if(result == NULL){
297
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
298
} else {
299
fprintf(stderr, "Unsupported algorithm: %s\n",
300
result->unsupported_algorithm);
301
fprintf(stderr, "Wrong key usage: %u\n",
302
result->wrong_key_usage);
303
if(result->file_name != NULL){
304
fprintf(stderr, "File name: %s\n", result->file_name);
305
}
306
gpgme_recipient_t recipient;
307
recipient = result->recipients;
308
if(recipient){
309
while(recipient != NULL){
310
fprintf(stderr, "Public key algorithm: %s\n",
311
gpgme_pubkey_algo_name(recipient->pubkey_algo));
312
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
313
fprintf(stderr, "Secret key available: %s\n",
314
recipient->status == GPG_ERR_NO_SECKEY
315
? "No" : "Yes");
316
recipient = recipient->next;
317
}
318
}
319
}
320
}
321
goto decrypt_end;
322
}
323
324
if(debug){
325
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
326
}
327
328
/* Seek back to the beginning of the GPGME plaintext data buffer */
329
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
330
perror("gpgme_data_seek");
331
plaintext_length = -1;
332
goto decrypt_end;
333
}
334
335
*plaintext = NULL;
336
while(true){
337
plaintext_capacity = incbuffer(plaintext,
338
(size_t)plaintext_length,
339
plaintext_capacity);
340
if(plaintext_capacity == 0){
341
perror("incbuffer");
342
plaintext_length = -1;
343
goto decrypt_end;
344
}
345
346
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
347
BUFFER_SIZE);
348
/* Print the data, if any */
349
if(ret == 0){
350
/* EOF */
351
break;
352
}
353
if(ret < 0){
354
perror("gpgme_data_read");
355
plaintext_length = -1;
356
goto decrypt_end;
357
}
358
plaintext_length += ret;
359
}
360
361
if(debug){
362
fprintf(stderr, "Decrypted password is: ");
363
for(ssize_t i = 0; i < plaintext_length; i++){
364
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
365
}
366
fprintf(stderr, "\n");
367
}
368
369
decrypt_end:
370
371
/* Delete the GPGME cryptotext data buffer */
372
gpgme_data_release(dh_crypto);
373
374
/* Delete the GPGME plaintext data buffer */
375
gpgme_data_release(dh_plain);
376
return plaintext_length;
377
}
378
379
static const char * safer_gnutls_strerror(int value){
380
const char *ret = gnutls_strerror(value); /* Spurious warning from
381
-Wunreachable-code */
382
if(ret == NULL)
383
ret = "(unknown)";
384
return ret;
385
}
386
387
/* GnuTLS log function callback */
388
static void debuggnutls(__attribute__((unused)) int level,
389
const char* string){
390
fprintf(stderr, "GnuTLS: %s", string);
391
}
392
393
static int init_gnutls_global(const char *pubkeyfilename,
394
const char *seckeyfilename){
395
int ret;
396
397
if(debug){
398
fprintf(stderr, "Initializing GnuTLS\n");
399
}
400
401
ret = gnutls_global_init();
402
if(ret != GNUTLS_E_SUCCESS){
403
fprintf(stderr, "GnuTLS global_init: %s\n",
404
safer_gnutls_strerror(ret));
405
return -1;
406
}
407
408
if(debug){
409
/* "Use a log level over 10 to enable all debugging options."
410
* - GnuTLS manual
411
*/
412
gnutls_global_set_log_level(11);
413
gnutls_global_set_log_function(debuggnutls);
414
}
415
416
/* OpenPGP credentials */
417
gnutls_certificate_allocate_credentials(&mc.cred);
418
if(ret != GNUTLS_E_SUCCESS){
419
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
420
from
421
-Wunreachable-code
422
*/
423
safer_gnutls_strerror(ret));
424
gnutls_global_deinit();
425
return -1;
426
}
427
428
if(debug){
429
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
430
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
431
seckeyfilename);
432
}
433
434
ret = gnutls_certificate_set_openpgp_key_file
435
(mc.cred, pubkeyfilename, seckeyfilename,
436
GNUTLS_OPENPGP_FMT_BASE64);
437
if(ret != GNUTLS_E_SUCCESS){
438
fprintf(stderr,
439
"Error[%d] while reading the OpenPGP key pair ('%s',"
440
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
441
fprintf(stderr, "The GnuTLS error is: %s\n",
442
safer_gnutls_strerror(ret));
443
goto globalfail;
444
}
445
446
/* GnuTLS server initialization */
447
ret = gnutls_dh_params_init(&mc.dh_params);
448
if(ret != GNUTLS_E_SUCCESS){
449
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
450
" %s\n", safer_gnutls_strerror(ret));
451
goto globalfail;
452
}
453
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
454
if(ret != GNUTLS_E_SUCCESS){
455
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
456
safer_gnutls_strerror(ret));
457
goto globalfail;
458
}
459
460
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
461
462
return 0;
463
464
globalfail:
465
466
gnutls_certificate_free_credentials(mc.cred);
467
gnutls_global_deinit();
468
gnutls_dh_params_deinit(mc.dh_params);
469
return -1;
470
}
471
472
static int init_gnutls_session(gnutls_session_t *session){
473
int ret;
474
/* GnuTLS session creation */
475
ret = gnutls_init(session, GNUTLS_SERVER);
476
if(ret != GNUTLS_E_SUCCESS){
477
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
478
safer_gnutls_strerror(ret));
479
}
480
481
{
482
const char *err;
483
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
484
if(ret != GNUTLS_E_SUCCESS){
485
fprintf(stderr, "Syntax error at: %s\n", err);
486
fprintf(stderr, "GnuTLS error: %s\n",
487
safer_gnutls_strerror(ret));
488
gnutls_deinit(*session);
489
return -1;
490
}
491
}
492
493
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
494
mc.cred);
495
if(ret != GNUTLS_E_SUCCESS){
496
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
497
safer_gnutls_strerror(ret));
498
gnutls_deinit(*session);
499
return -1;
500
}
501
502
/* ignore client certificate if any. */
503
gnutls_certificate_server_set_request(*session,
504
GNUTLS_CERT_IGNORE);
505
506
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
507
508
return 0;
509
}
510
511
/* Avahi log function callback */
512
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
513
__attribute__((unused)) const char *txt){}
514
515
/* Called when a Mandos server is found */
516
static int start_mandos_communication(const char *ip, uint16_t port,
517
AvahiIfIndex if_index,
518
int af){
519
int ret, tcp_sd;
520
ssize_t sret;
521
union {
522
struct sockaddr_in in;
523
struct sockaddr_in6 in6;
524
} to;
525
char *buffer = NULL;
526
char *decrypted_buffer;
527
size_t buffer_length = 0;
528
size_t buffer_capacity = 0;
529
ssize_t decrypted_buffer_size;
530
size_t written;
531
int retval = 0;
532
gnutls_session_t session;
533
int pf; /* Protocol family */
534
535
switch(af){
536
case AF_INET6:
537
pf = PF_INET6;
538
break;
539
case AF_INET:
540
pf = PF_INET;
541
break;
542
default:
543
fprintf(stderr, "Bad address family: %d\n", af);
544
return -1;
545
}
546
547
ret = init_gnutls_session(&session);
548
if(ret != 0){
549
return -1;
550
}
551
552
if(debug){
553
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
554
"\n", ip, port);
555
}
556
557
tcp_sd = socket(pf, SOCK_STREAM, 0);
558
if(tcp_sd < 0){
559
perror("socket");
560
return -1;
561
}
562
563
memset(&to, 0, sizeof(to));
564
if(af == AF_INET6){
565
to.in6.sin6_family = (uint16_t)af;
566
ret = inet_pton(af, ip, &to.in6.sin6_addr);
567
} else { /* IPv4 */
568
to.in.sin_family = (sa_family_t)af;
569
ret = inet_pton(af, ip, &to.in.sin_addr);
570
}
571
if(ret < 0 ){
572
perror("inet_pton");
573
return -1;
574
}
575
if(ret == 0){
576
fprintf(stderr, "Bad address: %s\n", ip);
577
return -1;
578
}
579
if(af == AF_INET6){
580
to.in6.sin6_port = htons(port); /* Spurious warnings from
581
-Wconversion and
582
-Wunreachable-code */
583
584
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
585
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
586
-Wunreachable-code*/
587
if(if_index == AVAHI_IF_UNSPEC){
588
fprintf(stderr, "An IPv6 link-local address is incomplete"
589
" without a network interface\n");
590
return -1;
591
}
592
/* Set the network interface number as scope */
593
to.in6.sin6_scope_id = (uint32_t)if_index;
594
}
595
} else {
596
to.in.sin_port = htons(port); /* Spurious warnings from
597
-Wconversion and
598
-Wunreachable-code */
599
}
600
601
if(debug){
602
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
603
char interface[IF_NAMESIZE];
604
if(if_indextoname((unsigned int)if_index, interface) == NULL){
605
perror("if_indextoname");
606
} else {
607
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
608
ip, interface, port);
609
}
610
} else {
611
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
612
port);
613
}
614
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
615
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
616
const char *pcret;
617
if(af == AF_INET6){
618
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
619
sizeof(addrstr));
620
} else {
621
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
622
sizeof(addrstr));
623
}
624
if(pcret == NULL){
625
perror("inet_ntop");
626
} else {
627
if(strcmp(addrstr, ip) != 0){
628
fprintf(stderr, "Canonical address form: %s\n", addrstr);
629
}
630
}
631
}
632
633
if(af == AF_INET6){
634
ret = connect(tcp_sd, &to.in6, sizeof(to));
635
} else {
636
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
637
}
638
if(ret < 0){
639
perror("connect");
640
return -1;
641
}
642
643
const char *out = mandos_protocol_version;
644
written = 0;
645
while(true){
646
size_t out_size = strlen(out);
647
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
648
out_size - written));
649
if(ret == -1){
650
perror("write");
651
retval = -1;
652
goto mandos_end;
653
}
654
written += (size_t)ret;
655
if(written < out_size){
656
continue;
657
} else {
658
if(out == mandos_protocol_version){
659
written = 0;
660
out = "\r\n";
661
} else {
662
break;
663
}
664
}
665
}
666
667
if(debug){
668
fprintf(stderr, "Establishing TLS session with %s\n", ip);
669
}
670
671
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
672
673
do{
674
ret = gnutls_handshake(session);
675
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
676
677
if(ret != GNUTLS_E_SUCCESS){
678
if(debug){
679
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
680
gnutls_perror(ret);
681
}
682
retval = -1;
683
goto mandos_end;
684
}
685
686
/* Read OpenPGP packet that contains the wanted password */
687
688
if(debug){
689
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
690
ip);
691
}
692
693
while(true){
694
buffer_capacity = incbuffer(&buffer, buffer_length,
695
buffer_capacity);
696
if(buffer_capacity == 0){
697
perror("incbuffer");
698
retval = -1;
699
goto mandos_end;
700
}
701
702
sret = gnutls_record_recv(session, buffer+buffer_length,
703
BUFFER_SIZE);
704
if(sret == 0){
705
break;
706
}
707
if(sret < 0){
708
switch(sret){
709
case GNUTLS_E_INTERRUPTED:
710
case GNUTLS_E_AGAIN:
711
break;
712
case GNUTLS_E_REHANDSHAKE:
713
do{
714
ret = gnutls_handshake(session);
715
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
716
if(ret < 0){
717
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
718
gnutls_perror(ret);
719
retval = -1;
720
goto mandos_end;
721
}
722
break;
723
default:
724
fprintf(stderr, "Unknown error while reading data from"
725
" encrypted session with Mandos server\n");
726
retval = -1;
727
gnutls_bye(session, GNUTLS_SHUT_RDWR);
728
goto mandos_end;
729
}
730
} else {
731
buffer_length += (size_t) sret;
732
}
733
}
734
735
if(debug){
736
fprintf(stderr, "Closing TLS session\n");
737
}
738
739
gnutls_bye(session, GNUTLS_SHUT_RDWR);
740
741
if(buffer_length > 0){
742
decrypted_buffer_size = pgp_packet_decrypt(buffer,
743
buffer_length,
744
&decrypted_buffer);
745
if(decrypted_buffer_size >= 0){
746
written = 0;
747
while(written < (size_t) decrypted_buffer_size){
748
ret = (int)fwrite(decrypted_buffer + written, 1,
749
(size_t)decrypted_buffer_size - written,
750
stdout);
751
if(ret == 0 and ferror(stdout)){
752
if(debug){
753
fprintf(stderr, "Error writing encrypted data: %s\n",
754
strerror(errno));
755
}
756
retval = -1;
757
break;
758
}
759
written += (size_t)ret;
760
}
761
free(decrypted_buffer);
762
} else {
763
retval = -1;
764
}
765
} else {
766
retval = -1;
767
}
768
769
/* Shutdown procedure */
770
771
mandos_end:
772
free(buffer);
773
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
774
if(ret == -1){
775
perror("close");
776
}
777
gnutls_deinit(session);
778
return retval;
779
}
780
781
static void resolve_callback(AvahiSServiceResolver *r,
782
AvahiIfIndex interface,
783
AvahiProtocol proto,
784
AvahiResolverEvent event,
785
const char *name,
786
const char *type,
787
const char *domain,
788
const char *host_name,
789
const AvahiAddress *address,
790
uint16_t port,
791
AVAHI_GCC_UNUSED AvahiStringList *txt,
792
AVAHI_GCC_UNUSED AvahiLookupResultFlags
793
flags,
794
AVAHI_GCC_UNUSED void* userdata){
795
assert(r);
796
797
/* Called whenever a service has been resolved successfully or
798
timed out */
799
800
switch(event){
801
default:
802
case AVAHI_RESOLVER_FAILURE:
803
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
804
" of type '%s' in domain '%s': %s\n", name, type, domain,
805
avahi_strerror(avahi_server_errno(mc.server)));
806
break;
807
808
case AVAHI_RESOLVER_FOUND:
809
{
810
char ip[AVAHI_ADDRESS_STR_MAX];
811
avahi_address_snprint(ip, sizeof(ip), address);
812
if(debug){
813
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
814
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
815
ip, (intmax_t)interface, port);
816
}
817
int ret = start_mandos_communication(ip, port, interface,
818
avahi_proto_to_af(proto));
819
if(ret == 0){
820
avahi_simple_poll_quit(mc.simple_poll);
821
}
822
}
823
}
824
avahi_s_service_resolver_free(r);
825
}
826
827
static void browse_callback(AvahiSServiceBrowser *b,
828
AvahiIfIndex interface,
829
AvahiProtocol protocol,
830
AvahiBrowserEvent event,
831
const char *name,
832
const char *type,
833
const char *domain,
834
AVAHI_GCC_UNUSED AvahiLookupResultFlags
835
flags,
836
AVAHI_GCC_UNUSED void* userdata){
837
assert(b);
838
839
/* Called whenever a new services becomes available on the LAN or
840
is removed from the LAN */
841
842
switch(event){
843
default:
844
case AVAHI_BROWSER_FAILURE:
845
846
fprintf(stderr, "(Avahi browser) %s\n",
847
avahi_strerror(avahi_server_errno(mc.server)));
848
avahi_simple_poll_quit(mc.simple_poll);
849
return;
850
851
case AVAHI_BROWSER_NEW:
852
/* We ignore the returned Avahi resolver object. In the callback
853
function we free it. If the Avahi server is terminated before
854
the callback function is called the Avahi server will free the
855
resolver for us. */
856
857
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
858
name, type, domain, protocol, 0,
859
resolve_callback, NULL) == NULL)
860
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
861
name, avahi_strerror(avahi_server_errno(mc.server)));
862
break;
863
864
case AVAHI_BROWSER_REMOVE:
865
break;
866
867
case AVAHI_BROWSER_ALL_FOR_NOW:
868
case AVAHI_BROWSER_CACHE_EXHAUSTED:
869
if(debug){
870
fprintf(stderr, "No Mandos server found, still searching...\n");
871
}
872
break;
873
}
874
}
875
876
sig_atomic_t quit_now = 0;
877
878
/* stop main loop after sigterm has been called */
879
static void handle_sigterm(__attribute__((unused)) int sig){
880
if(quit_now){
881
return;
882
}
883
quit_now = 1;
884
int old_errno = errno;
885
if(mc.simple_poll != NULL){
886
avahi_simple_poll_quit(mc.simple_poll);
887
}
888
errno = old_errno;
889
}
890
891
int main(int argc, char *argv[]){
892
AvahiSServiceBrowser *sb = NULL;
893
int error;
894
int ret;
895
intmax_t tmpmax;
896
char *tmp;
897
int exitcode = EXIT_SUCCESS;
898
const char *interface = "eth0";
899
struct ifreq network;
900
int sd;
901
uid_t uid;
902
gid_t gid;
903
char *connect_to = NULL;
904
char tempdir[] = "/tmp/mandosXXXXXX";
905
bool tempdir_created = false;
906
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
907
const char *seckey = PATHDIR "/" SECKEY;
908
const char *pubkey = PATHDIR "/" PUBKEY;
909
910
bool gnutls_initialized = false;
911
bool gpgme_initialized = false;
912
float delay = 2.5f;
913
914
struct sigaction old_sigterm_action;
915
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
916
917
{
918
struct argp_option options[] = {
919
{ .name = "debug", .key = 128,
920
.doc = "Debug mode", .group = 3 },
921
{ .name = "connect", .key = 'c',
922
.arg = "ADDRESS:PORT",
923
.doc = "Connect directly to a specific Mandos server",
924
.group = 1 },
925
{ .name = "interface", .key = 'i',
926
.arg = "NAME",
927
.doc = "Network interface that will be used to search for"
928
" Mandos servers",
929
.group = 1 },
930
{ .name = "seckey", .key = 's',
931
.arg = "FILE",
932
.doc = "OpenPGP secret key file base name",
933
.group = 1 },
934
{ .name = "pubkey", .key = 'p',
935
.arg = "FILE",
936
.doc = "OpenPGP public key file base name",
937
.group = 2 },
938
{ .name = "dh-bits", .key = 129,
939
.arg = "BITS",
940
.doc = "Bit length of the prime number used in the"
941
" Diffie-Hellman key exchange",
942
.group = 2 },
943
{ .name = "priority", .key = 130,
944
.arg = "STRING",
945
.doc = "GnuTLS priority string for the TLS handshake",
946
.group = 1 },
947
{ .name = "delay", .key = 131,
948
.arg = "SECONDS",
949
.doc = "Maximum delay to wait for interface startup",
950
.group = 2 },
951
{ .name = NULL }
952
};
953
954
error_t parse_opt(int key, char *arg,
955
struct argp_state *state){
956
switch(key){
957
case 128: /* --debug */
958
debug = true;
959
break;
960
case 'c': /* --connect */
961
connect_to = arg;
962
break;
963
case 'i': /* --interface */
964
interface = arg;
965
break;
966
case 's': /* --seckey */
967
seckey = arg;
968
break;
969
case 'p': /* --pubkey */
970
pubkey = arg;
971
break;
972
case 129: /* --dh-bits */
973
errno = 0;
974
tmpmax = strtoimax(arg, &tmp, 10);
975
if(errno != 0 or tmp == arg or *tmp != '\0'
976
or tmpmax != (typeof(mc.dh_bits))tmpmax){
977
fprintf(stderr, "Bad number of DH bits\n");
978
exit(EXIT_FAILURE);
979
}
980
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
981
break;
982
case 130: /* --priority */
983
mc.priority = arg;
984
break;
985
case 131: /* --delay */
986
errno = 0;
987
delay = strtof(arg, &tmp);
988
if(errno != 0 or tmp == arg or *tmp != '\0'){
989
fprintf(stderr, "Bad delay\n");
990
exit(EXIT_FAILURE);
991
}
992
break;
993
case ARGP_KEY_ARG:
994
argp_usage(state);
995
case ARGP_KEY_END:
996
break;
997
default:
998
return ARGP_ERR_UNKNOWN;
999
}
1000
return 0;
1001
}
1002
1003
struct argp argp = { .options = options, .parser = parse_opt,
1004
.args_doc = "",
1005
.doc = "Mandos client -- Get and decrypt"
1006
" passwords from a Mandos server" };
1007
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1008
if(ret == ARGP_ERR_UNKNOWN){
1009
fprintf(stderr, "Unknown error while parsing arguments\n");
1010
exitcode = EXIT_FAILURE;
1011
goto end;
1012
}
1013
}
1014
1015
if(not debug){
1016
avahi_set_log_function(empty_log);
1017
}
1018
1019
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1020
from the signal handler */
1021
/* Initialize the pseudo-RNG for Avahi */
1022
srand((unsigned int) time(NULL));
1023
mc.simple_poll = avahi_simple_poll_new();
1024
if(mc.simple_poll == NULL){
1025
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1026
exitcode = EXIT_FAILURE;
1027
goto end;
1028
}
1029
1030
sigemptyset(&sigterm_action.sa_mask);
1031
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1032
if(ret == -1){
1033
perror("sigaddset");
1034
exitcode = EXIT_FAILURE;
1035
goto end;
1036
}
1037
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1038
if(ret == -1){
1039
perror("sigaddset");
1040
exitcode = EXIT_FAILURE;
1041
goto end;
1042
}
1043
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1044
if(ret == -1){
1045
perror("sigaddset");
1046
exitcode = EXIT_FAILURE;
1047
goto end;
1048
}
1049
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1050
if(ret == -1){
1051
perror("sigaction");
1052
exitcode = EXIT_FAILURE;
1053
goto end;
1054
}
1055
1056
/* If the interface is down, bring it up */
1057
if(interface[0] != '\0'){
1058
#ifdef __linux__
1059
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1060
messages to mess up the prompt */
1061
ret = klogctl(8, NULL, 5);
1062
bool restore_loglevel = true;
1063
if(ret == -1){
1064
restore_loglevel = false;
1065
perror("klogctl");
1066
}
1067
#endif /* __linux__ */
1068
1069
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1070
if(sd < 0){
1071
perror("socket");
1072
exitcode = EXIT_FAILURE;
1073
#ifdef __linux__
1074
if(restore_loglevel){
1075
ret = klogctl(7, NULL, 0);
1076
if(ret == -1){
1077
perror("klogctl");
1078
}
1079
}
1080
#endif /* __linux__ */
1081
goto end;
1082
}
1083
strcpy(network.ifr_name, interface);
1084
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1085
if(ret == -1){
1086
perror("ioctl SIOCGIFFLAGS");
1087
#ifdef __linux__
1088
if(restore_loglevel){
1089
ret = klogctl(7, NULL, 0);
1090
if(ret == -1){
1091
perror("klogctl");
1092
}
1093
}
1094
#endif /* __linux__ */
1095
exitcode = EXIT_FAILURE;
1096
goto end;
1097
}
1098
if((network.ifr_flags & IFF_UP) == 0){
1099
network.ifr_flags |= IFF_UP;
1100
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1101
if(ret == -1){
1102
perror("ioctl SIOCSIFFLAGS");
1103
exitcode = EXIT_FAILURE;
1104
#ifdef __linux__
1105
if(restore_loglevel){
1106
ret = klogctl(7, NULL, 0);
1107
if(ret == -1){
1108
perror("klogctl");
1109
}
1110
}
1111
#endif /* __linux__ */
1112
goto end;
1113
}
1114
}
1115
/* sleep checking until interface is running */
1116
for(int i=0; i < delay * 4; i++){
1117
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1118
if(ret == -1){
1119
perror("ioctl SIOCGIFFLAGS");
1120
} else if(network.ifr_flags & IFF_RUNNING){
1121
break;
1122
}
1123
struct timespec sleeptime = { .tv_nsec = 250000000 };
1124
ret = nanosleep(&sleeptime, NULL);
1125
if(ret == -1 and errno != EINTR){
1126
perror("nanosleep");
1127
}
1128
}
1129
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1130
if(ret == -1){
1131
perror("close");
1132
}
1133
#ifdef __linux__
1134
if(restore_loglevel){
1135
/* Restores kernel loglevel to default */
1136
ret = klogctl(7, NULL, 0);
1137
if(ret == -1){
1138
perror("klogctl");
1139
}
1140
}
1141
#endif /* __linux__ */
1142
}
1143
1144
uid = getuid();
1145
gid = getgid();
1146
1147
errno = 0;
1148
setgid(gid);
1149
if(ret == -1){
1150
perror("setgid");
1151
}
1152
1153
ret = setuid(uid);
1154
if(ret == -1){
1155
perror("setuid");
1156
}
1157
1158
ret = init_gnutls_global(pubkey, seckey);
1159
if(ret == -1){
1160
fprintf(stderr, "init_gnutls_global failed\n");
1161
exitcode = EXIT_FAILURE;
1162
goto end;
1163
} else {
1164
gnutls_initialized = true;
1165
}
1166
1167
if(mkdtemp(tempdir) == NULL){
1168
perror("mkdtemp");
1169
goto end;
1170
}
1171
tempdir_created = true;
1172
1173
if(not init_gpgme(pubkey, seckey, tempdir)){
1174
fprintf(stderr, "init_gpgme failed\n");
1175
exitcode = EXIT_FAILURE;
1176
goto end;
1177
} else {
1178
gpgme_initialized = true;
1179
}
1180
1181
if(interface[0] != '\0'){
1182
if_index = (AvahiIfIndex) if_nametoindex(interface);
1183
if(if_index == 0){
1184
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1185
exitcode = EXIT_FAILURE;
1186
goto end;
1187
}
1188
}
1189
1190
if(connect_to != NULL){
1191
/* Connect directly, do not use Zeroconf */
1192
/* (Mainly meant for debugging) */
1193
char *address = strrchr(connect_to, ':');
1194
if(address == NULL){
1195
fprintf(stderr, "No colon in address\n");
1196
exitcode = EXIT_FAILURE;
1197
goto end;
1198
}
1199
uint16_t port;
1200
errno = 0;
1201
tmpmax = strtoimax(address+1, &tmp, 10);
1202
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1203
or tmpmax != (uint16_t)tmpmax){
1204
fprintf(stderr, "Bad port number\n");
1205
exitcode = EXIT_FAILURE;
1206
goto end;
1207
}
1208
port = (uint16_t)tmpmax;
1209
*address = '\0';
1210
address = connect_to;
1211
/* Colon in address indicates IPv6 */
1212
int af;
1213
if(strchr(address, ':') != NULL){
1214
af = AF_INET6;
1215
} else {
1216
af = AF_INET;
1217
}
1218
ret = start_mandos_communication(address, port, if_index, af);
1219
if(ret < 0){
1220
exitcode = EXIT_FAILURE;
1221
} else {
1222
exitcode = EXIT_SUCCESS;
1223
}
1224
goto end;
1225
}
1226
1227
{
1228
AvahiServerConfig config;
1229
/* Do not publish any local Zeroconf records */
1230
avahi_server_config_init(&config);
1231
config.publish_hinfo = 0;
1232
config.publish_addresses = 0;
1233
config.publish_workstation = 0;
1234
config.publish_domain = 0;
1235
1236
/* Allocate a new server */
1237
mc.server = avahi_server_new(avahi_simple_poll_get
1238
(mc.simple_poll), &config, NULL,
1239
NULL, &error);
1240
1241
/* Free the Avahi configuration data */
1242
avahi_server_config_free(&config);
1243
}
1244
1245
/* Check if creating the Avahi server object succeeded */
1246
if(mc.server == NULL){
1247
fprintf(stderr, "Failed to create Avahi server: %s\n",
1248
avahi_strerror(error));
1249
exitcode = EXIT_FAILURE;
1250
goto end;
1251
}
1252
1253
/* Create the Avahi service browser */
1254
sb = avahi_s_service_browser_new(mc.server, if_index,
1255
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1256
NULL, 0, browse_callback, NULL);
1257
if(sb == NULL){
1258
fprintf(stderr, "Failed to create service browser: %s\n",
1259
avahi_strerror(avahi_server_errno(mc.server)));
1260
exitcode = EXIT_FAILURE;
1261
goto end;
1262
}
1263
1264
/* Run the main loop */
1265
1266
if(debug){
1267
fprintf(stderr, "Starting Avahi loop search\n");
1268
}
1269
1270
avahi_simple_poll_loop(mc.simple_poll);
1271
1272
end:
1273
1274
if(debug){
1275
fprintf(stderr, "%s exiting\n", argv[0]);
1276
}
1277
1278
/* Cleanup things */
1279
if(sb != NULL)
1280
avahi_s_service_browser_free(sb);
1281
1282
if(mc.server != NULL)
1283
avahi_server_free(mc.server);
1284
1285
if(mc.simple_poll != NULL)
1286
avahi_simple_poll_free(mc.simple_poll);
1287
1288
if(gnutls_initialized){
1289
gnutls_certificate_free_credentials(mc.cred);
1290
gnutls_global_deinit();
1291
gnutls_dh_params_deinit(mc.dh_params);
1292
}
1293
1294
if(gpgme_initialized){
1295
gpgme_release(mc.ctx);
1296
}
1297
1298
/* Removes the temp directory used by GPGME */
1299
if(tempdir_created){
1300
DIR *d;
1301
struct dirent *direntry;
1302
d = opendir(tempdir);
1303
if(d == NULL){
1304
if(errno != ENOENT){
1305
perror("opendir");
1306
}
1307
} else {
1308
while(true){
1309
direntry = readdir(d);
1310
if(direntry == NULL){
1311
break;
1312
}
1313
/* Skip "." and ".." */
1314
if(direntry->d_name[0] == '.'
1315
and (direntry->d_name[1] == '\0'
1316
or (direntry->d_name[1] == '.'
1317
and direntry->d_name[2] == '\0'))){
1318
continue;
1319
}
1320
char *fullname = NULL;
1321
ret = asprintf(&fullname, "%s/%s", tempdir,
1322
direntry->d_name);
1323
if(ret < 0){
1324
perror("asprintf");
1325
continue;
1326
}
1327
ret = remove(fullname);
1328
if(ret == -1){
1329
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1330
strerror(errno));
1331
}
1332
free(fullname);
1333
}
1334
closedir(d);
1335
}
1336
ret = rmdir(tempdir);
1337
if(ret == -1 and errno != ENOENT){
1338
perror("rmdir");
1339
}
1340
}
1341
1342
return exitcode;
1343
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0