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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
- 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
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
35
#endif
36
#ifndef _FILE_OFFSET_BITS
37
#define _FILE_OFFSET_BITS 64
38
#endif
39
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
41
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t */
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
47
srand(), strtof() */
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
55
opendir(), DIR */
56
#include <sys/stat.h> /* open() */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
61
*/
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
63
strtoimax() */
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
SIOCSIFFLAGS, if_indextoname(),
69
if_nametoindex(), IF_NAMESIZE */
70
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
72
*/
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), setuid(),
75
setgid() */
76
#include <arpa/inet.h> /* inet_pton(), htons */
77
#include <iso646.h> /* not, or, and */
78
#include <argp.h> /* struct argp_option, error_t, struct
79
argp_state, struct argp,
80
argp_parse(), ARGP_KEY_ARG,
81
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
#include <signal.h> /* sigemptyset(), sigaddset(),
83
sigaction(), SIGTERM, sigaction,
84
sig_atomic_t */
85
86
#ifdef __linux__
87
#include <sys/klog.h> /* klogctl() */
88
#endif /* __linux__ */
89
90
/* Avahi */
91
/* All Avahi types, constants and functions
92
Avahi*, avahi_*,
93
AVAHI_* */
94
#include <avahi-core/core.h>
95
#include <avahi-core/lookup.h>
96
#include <avahi-core/log.h>
97
#include <avahi-common/simple-watch.h>
98
#include <avahi-common/malloc.h>
99
#include <avahi-common/error.h>
100
101
/* GnuTLS */
102
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
103
functions:
104
gnutls_*
105
init_gnutls_session(),
106
GNUTLS_* */
107
#include <gnutls/openpgp.h>
108
/* gnutls_certificate_set_openpgp_key_file(),
109
GNUTLS_OPENPGP_FMT_BASE64 */
110
111
/* GPGME */
112
#include <gpgme.h> /* All GPGME types, constants and
113
functions:
114
gpgme_*
115
GPGME_PROTOCOL_OpenPGP,
116
GPG_ERR_NO_* */
117
118
#define BUFFER_SIZE 256
119
120
#define PATHDIR "/conf/conf.d/mandos"
121
#define SECKEY "seckey.txt"
122
#define PUBKEY "pubkey.txt"
123
124
bool debug = false;
125
static const char mandos_protocol_version[] = "1";
126
const char *argp_program_version = "mandos-client " VERSION;
127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
128
129
/* Used for passing in values through the Avahi callback functions */
130
typedef struct {
131
AvahiSimplePoll *simple_poll;
132
AvahiServer *server;
133
gnutls_certificate_credentials_t cred;
134
unsigned int dh_bits;
135
gnutls_dh_params_t dh_params;
136
const char *priority;
137
gpgme_ctx_t ctx;
138
} mandos_context;
139
140
/* global context so signal handler can reach it*/
141
mandos_context mc = { .simple_poll = NULL, .server = NULL,
142
.dh_bits = 1024, .priority = "SECURE256"
143
":!CTYPE-X.509:+CTYPE-OPENPGP" };
144
145
/*
146
* Make additional room in "buffer" for at least BUFFER_SIZE more
147
* bytes. "buffer_capacity" is how much is currently allocated,
148
* "buffer_length" is how much is already used.
149
*/
150
size_t incbuffer(char **buffer, size_t buffer_length,
151
size_t buffer_capacity){
152
if(buffer_length + BUFFER_SIZE > buffer_capacity){
153
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
154
if(buffer == NULL){
155
return 0;
156
}
157
buffer_capacity += BUFFER_SIZE;
158
}
159
return buffer_capacity;
160
}
161
162
/*
163
* Initialize GPGME.
164
*/
165
static bool init_gpgme(const char *seckey,
166
const char *pubkey, const char *tempdir){
167
int ret;
168
gpgme_error_t rc;
169
gpgme_engine_info_t engine_info;
170
171
172
/*
173
* Helper function to insert pub and seckey to the engine keyring.
174
*/
175
bool import_key(const char *filename){
176
int fd;
177
gpgme_data_t pgp_data;
178
179
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
180
if(fd == -1){
181
perror("open");
182
return false;
183
}
184
185
rc = gpgme_data_new_from_fd(&pgp_data, fd);
186
if(rc != GPG_ERR_NO_ERROR){
187
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
188
gpgme_strsource(rc), gpgme_strerror(rc));
189
return false;
190
}
191
192
rc = gpgme_op_import(mc.ctx, pgp_data);
193
if(rc != GPG_ERR_NO_ERROR){
194
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
195
gpgme_strsource(rc), gpgme_strerror(rc));
196
return false;
197
}
198
199
ret = (int)TEMP_FAILURE_RETRY(close(fd));
200
if(ret == -1){
201
perror("close");
202
}
203
gpgme_data_release(pgp_data);
204
return true;
205
}
206
207
if(debug){
208
fprintf(stderr, "Initializing GPGME\n");
209
}
210
211
/* Init GPGME */
212
gpgme_check_version(NULL);
213
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
214
if(rc != GPG_ERR_NO_ERROR){
215
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
216
gpgme_strsource(rc), gpgme_strerror(rc));
217
return false;
218
}
219
220
/* Set GPGME home directory for the OpenPGP engine only */
221
rc = gpgme_get_engine_info(&engine_info);
222
if(rc != GPG_ERR_NO_ERROR){
223
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
224
gpgme_strsource(rc), gpgme_strerror(rc));
225
return false;
226
}
227
while(engine_info != NULL){
228
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
229
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
230
engine_info->file_name, tempdir);
231
break;
232
}
233
engine_info = engine_info->next;
234
}
235
if(engine_info == NULL){
236
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
237
return false;
238
}
239
240
/* Create new GPGME "context" */
241
rc = gpgme_new(&(mc.ctx));
242
if(rc != GPG_ERR_NO_ERROR){
243
fprintf(stderr, "bad gpgme_new: %s: %s\n",
244
gpgme_strsource(rc), gpgme_strerror(rc));
245
return false;
246
}
247
248
if(not import_key(pubkey) or not import_key(seckey)){
249
return false;
250
}
251
252
return true;
253
}
254
255
/*
256
* Decrypt OpenPGP data.
257
* Returns -1 on error
258
*/
259
static ssize_t pgp_packet_decrypt(const char *cryptotext,
260
size_t crypto_size,
261
char **plaintext){
262
gpgme_data_t dh_crypto, dh_plain;
263
gpgme_error_t rc;
264
ssize_t ret;
265
size_t plaintext_capacity = 0;
266
ssize_t plaintext_length = 0;
267
268
if(debug){
269
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
270
}
271
272
/* Create new GPGME data buffer from memory cryptotext */
273
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
274
0);
275
if(rc != GPG_ERR_NO_ERROR){
276
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
277
gpgme_strsource(rc), gpgme_strerror(rc));
278
return -1;
279
}
280
281
/* Create new empty GPGME data buffer for the plaintext */
282
rc = gpgme_data_new(&dh_plain);
283
if(rc != GPG_ERR_NO_ERROR){
284
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
285
gpgme_strsource(rc), gpgme_strerror(rc));
286
gpgme_data_release(dh_crypto);
287
return -1;
288
}
289
290
/* Decrypt data from the cryptotext data buffer to the plaintext
291
data buffer */
292
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
293
if(rc != GPG_ERR_NO_ERROR){
294
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
295
gpgme_strsource(rc), gpgme_strerror(rc));
296
plaintext_length = -1;
297
if(debug){
298
gpgme_decrypt_result_t result;
299
result = gpgme_op_decrypt_result(mc.ctx);
300
if(result == NULL){
301
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
302
} else {
303
fprintf(stderr, "Unsupported algorithm: %s\n",
304
result->unsupported_algorithm);
305
fprintf(stderr, "Wrong key usage: %u\n",
306
result->wrong_key_usage);
307
if(result->file_name != NULL){
308
fprintf(stderr, "File name: %s\n", result->file_name);
309
}
310
gpgme_recipient_t recipient;
311
recipient = result->recipients;
312
if(recipient){
313
while(recipient != NULL){
314
fprintf(stderr, "Public key algorithm: %s\n",
315
gpgme_pubkey_algo_name(recipient->pubkey_algo));
316
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
317
fprintf(stderr, "Secret key available: %s\n",
318
recipient->status == GPG_ERR_NO_SECKEY
319
? "No" : "Yes");
320
recipient = recipient->next;
321
}
322
}
323
}
324
}
325
goto decrypt_end;
326
}
327
328
if(debug){
329
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
330
}
331
332
/* Seek back to the beginning of the GPGME plaintext data buffer */
333
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
334
perror("gpgme_data_seek");
335
plaintext_length = -1;
336
goto decrypt_end;
337
}
338
339
*plaintext = NULL;
340
while(true){
341
plaintext_capacity = incbuffer(plaintext,
342
(size_t)plaintext_length,
343
plaintext_capacity);
344
if(plaintext_capacity == 0){
345
perror("incbuffer");
346
plaintext_length = -1;
347
goto decrypt_end;
348
}
349
350
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
351
BUFFER_SIZE);
352
/* Print the data, if any */
353
if(ret == 0){
354
/* EOF */
355
break;
356
}
357
if(ret < 0){
358
perror("gpgme_data_read");
359
plaintext_length = -1;
360
goto decrypt_end;
361
}
362
plaintext_length += ret;
363
}
364
365
if(debug){
366
fprintf(stderr, "Decrypted password is: ");
367
for(ssize_t i = 0; i < plaintext_length; i++){
368
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
369
}
370
fprintf(stderr, "\n");
371
}
372
373
decrypt_end:
374
375
/* Delete the GPGME cryptotext data buffer */
376
gpgme_data_release(dh_crypto);
377
378
/* Delete the GPGME plaintext data buffer */
379
gpgme_data_release(dh_plain);
380
return plaintext_length;
381
}
382
383
static const char * safer_gnutls_strerror(int value){
384
const char *ret = gnutls_strerror(value); /* Spurious warning from
385
-Wunreachable-code */
386
if(ret == NULL)
387
ret = "(unknown)";
388
return ret;
389
}
390
391
/* GnuTLS log function callback */
392
static void debuggnutls(__attribute__((unused)) int level,
393
const char* string){
394
fprintf(stderr, "GnuTLS: %s", string);
395
}
396
397
static int init_gnutls_global(const char *pubkeyfilename,
398
const char *seckeyfilename){
399
int ret;
400
401
if(debug){
402
fprintf(stderr, "Initializing GnuTLS\n");
403
}
404
405
ret = gnutls_global_init();
406
if(ret != GNUTLS_E_SUCCESS){
407
fprintf(stderr, "GnuTLS global_init: %s\n",
408
safer_gnutls_strerror(ret));
409
return -1;
410
}
411
412
if(debug){
413
/* "Use a log level over 10 to enable all debugging options."
414
* - GnuTLS manual
415
*/
416
gnutls_global_set_log_level(11);
417
gnutls_global_set_log_function(debuggnutls);
418
}
419
420
/* OpenPGP credentials */
421
gnutls_certificate_allocate_credentials(&mc.cred);
422
if(ret != GNUTLS_E_SUCCESS){
423
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
424
from
425
-Wunreachable-code
426
*/
427
safer_gnutls_strerror(ret));
428
gnutls_global_deinit();
429
return -1;
430
}
431
432
if(debug){
433
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
434
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
435
seckeyfilename);
436
}
437
438
ret = gnutls_certificate_set_openpgp_key_file
439
(mc.cred, pubkeyfilename, seckeyfilename,
440
GNUTLS_OPENPGP_FMT_BASE64);
441
if(ret != GNUTLS_E_SUCCESS){
442
fprintf(stderr,
443
"Error[%d] while reading the OpenPGP key pair ('%s',"
444
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
445
fprintf(stderr, "The GnuTLS error is: %s\n",
446
safer_gnutls_strerror(ret));
447
goto globalfail;
448
}
449
450
/* GnuTLS server initialization */
451
ret = gnutls_dh_params_init(&mc.dh_params);
452
if(ret != GNUTLS_E_SUCCESS){
453
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
454
" %s\n", safer_gnutls_strerror(ret));
455
goto globalfail;
456
}
457
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
458
if(ret != GNUTLS_E_SUCCESS){
459
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
460
safer_gnutls_strerror(ret));
461
goto globalfail;
462
}
463
464
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
465
466
return 0;
467
468
globalfail:
469
470
gnutls_certificate_free_credentials(mc.cred);
471
gnutls_global_deinit();
472
gnutls_dh_params_deinit(mc.dh_params);
473
return -1;
474
}
475
476
static int init_gnutls_session(gnutls_session_t *session){
477
int ret;
478
/* GnuTLS session creation */
479
ret = gnutls_init(session, GNUTLS_SERVER);
480
if(ret != GNUTLS_E_SUCCESS){
481
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
482
safer_gnutls_strerror(ret));
483
}
484
485
{
486
const char *err;
487
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
488
if(ret != GNUTLS_E_SUCCESS){
489
fprintf(stderr, "Syntax error at: %s\n", err);
490
fprintf(stderr, "GnuTLS error: %s\n",
491
safer_gnutls_strerror(ret));
492
gnutls_deinit(*session);
493
return -1;
494
}
495
}
496
497
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
498
mc.cred);
499
if(ret != GNUTLS_E_SUCCESS){
500
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
501
safer_gnutls_strerror(ret));
502
gnutls_deinit(*session);
503
return -1;
504
}
505
506
/* ignore client certificate if any. */
507
gnutls_certificate_server_set_request(*session,
508
GNUTLS_CERT_IGNORE);
509
510
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
511
512
return 0;
513
}
514
515
/* Avahi log function callback */
516
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
517
__attribute__((unused)) const char *txt){}
518
519
/* Called when a Mandos server is found */
520
static int start_mandos_communication(const char *ip, uint16_t port,
521
AvahiIfIndex if_index,
522
int af){
523
int ret, tcp_sd;
524
ssize_t sret;
525
union {
526
struct sockaddr_in in;
527
struct sockaddr_in6 in6;
528
} to;
529
char *buffer = NULL;
530
char *decrypted_buffer;
531
size_t buffer_length = 0;
532
size_t buffer_capacity = 0;
533
ssize_t decrypted_buffer_size;
534
size_t written;
535
int retval = 0;
536
gnutls_session_t session;
537
int pf; /* Protocol family */
538
539
switch(af){
540
case AF_INET6:
541
pf = PF_INET6;
542
break;
543
case AF_INET:
544
pf = PF_INET;
545
break;
546
default:
547
fprintf(stderr, "Bad address family: %d\n", af);
548
return -1;
549
}
550
551
ret = init_gnutls_session(&session);
552
if(ret != 0){
553
return -1;
554
}
555
556
if(debug){
557
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
558
"\n", ip, port);
559
}
560
561
tcp_sd = socket(pf, SOCK_STREAM, 0);
562
if(tcp_sd < 0){
563
perror("socket");
564
return -1;
565
}
566
567
memset(&to, 0, sizeof(to));
568
if(af == AF_INET6){
569
to.in6.sin6_family = (sa_family_t)af;
570
ret = inet_pton(af, ip, &to.in6.sin6_addr);
571
} else { /* IPv4 */
572
to.in.sin_family = (sa_family_t)af;
573
ret = inet_pton(af, ip, &to.in.sin_addr);
574
}
575
if(ret < 0 ){
576
perror("inet_pton");
577
return -1;
578
}
579
if(ret == 0){
580
fprintf(stderr, "Bad address: %s\n", ip);
581
return -1;
582
}
583
if(af == AF_INET6){
584
to.in6.sin6_port = htons(port); /* Spurious warnings from
585
-Wconversion and
586
-Wunreachable-code */
587
588
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
589
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
590
-Wunreachable-code*/
591
if(if_index == AVAHI_IF_UNSPEC){
592
fprintf(stderr, "An IPv6 link-local address is incomplete"
593
" without a network interface\n");
594
return -1;
595
}
596
/* Set the network interface number as scope */
597
to.in6.sin6_scope_id = (uint32_t)if_index;
598
}
599
} else {
600
to.in.sin_port = htons(port); /* Spurious warnings from
601
-Wconversion and
602
-Wunreachable-code */
603
}
604
605
if(debug){
606
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
607
char interface[IF_NAMESIZE];
608
if(if_indextoname((unsigned int)if_index, interface) == NULL){
609
perror("if_indextoname");
610
} else {
611
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
612
ip, interface, port);
613
}
614
} else {
615
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
616
port);
617
}
618
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
619
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
620
const char *pcret;
621
if(af == AF_INET6){
622
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
623
sizeof(addrstr));
624
} else {
625
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
626
sizeof(addrstr));
627
}
628
if(pcret == NULL){
629
perror("inet_ntop");
630
} else {
631
if(strcmp(addrstr, ip) != 0){
632
fprintf(stderr, "Canonical address form: %s\n", addrstr);
633
}
634
}
635
}
636
637
if(af == AF_INET6){
638
ret = connect(tcp_sd, &to.in6, sizeof(to));
639
} else {
640
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
641
}
642
if(ret < 0){
643
perror("connect");
644
return -1;
645
}
646
647
const char *out = mandos_protocol_version;
648
written = 0;
649
while(true){
650
size_t out_size = strlen(out);
651
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
652
out_size - written));
653
if(ret == -1){
654
perror("write");
655
retval = -1;
656
goto mandos_end;
657
}
658
written += (size_t)ret;
659
if(written < out_size){
660
continue;
661
} else {
662
if(out == mandos_protocol_version){
663
written = 0;
664
out = "\r\n";
665
} else {
666
break;
667
}
668
}
669
}
670
671
if(debug){
672
fprintf(stderr, "Establishing TLS session with %s\n", ip);
673
}
674
675
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
676
677
do{
678
ret = gnutls_handshake(session);
679
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
680
681
if(ret != GNUTLS_E_SUCCESS){
682
if(debug){
683
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
684
gnutls_perror(ret);
685
}
686
retval = -1;
687
goto mandos_end;
688
}
689
690
/* Read OpenPGP packet that contains the wanted password */
691
692
if(debug){
693
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
694
ip);
695
}
696
697
while(true){
698
buffer_capacity = incbuffer(&buffer, buffer_length,
699
buffer_capacity);
700
if(buffer_capacity == 0){
701
perror("incbuffer");
702
retval = -1;
703
goto mandos_end;
704
}
705
706
sret = gnutls_record_recv(session, buffer+buffer_length,
707
BUFFER_SIZE);
708
if(sret == 0){
709
break;
710
}
711
if(sret < 0){
712
switch(sret){
713
case GNUTLS_E_INTERRUPTED:
714
case GNUTLS_E_AGAIN:
715
break;
716
case GNUTLS_E_REHANDSHAKE:
717
do{
718
ret = gnutls_handshake(session);
719
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
720
if(ret < 0){
721
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
722
gnutls_perror(ret);
723
retval = -1;
724
goto mandos_end;
725
}
726
break;
727
default:
728
fprintf(stderr, "Unknown error while reading data from"
729
" encrypted session with Mandos server\n");
730
retval = -1;
731
gnutls_bye(session, GNUTLS_SHUT_RDWR);
732
goto mandos_end;
733
}
734
} else {
735
buffer_length += (size_t) sret;
736
}
737
}
738
739
if(debug){
740
fprintf(stderr, "Closing TLS session\n");
741
}
742
743
gnutls_bye(session, GNUTLS_SHUT_RDWR);
744
745
if(buffer_length > 0){
746
decrypted_buffer_size = pgp_packet_decrypt(buffer,
747
buffer_length,
748
&decrypted_buffer);
749
if(decrypted_buffer_size >= 0){
750
written = 0;
751
while(written < (size_t) decrypted_buffer_size){
752
ret = (int)fwrite(decrypted_buffer + written, 1,
753
(size_t)decrypted_buffer_size - written,
754
stdout);
755
if(ret == 0 and ferror(stdout)){
756
if(debug){
757
fprintf(stderr, "Error writing encrypted data: %s\n",
758
strerror(errno));
759
}
760
retval = -1;
761
break;
762
}
763
written += (size_t)ret;
764
}
765
free(decrypted_buffer);
766
} else {
767
retval = -1;
768
}
769
} else {
770
retval = -1;
771
}
772
773
/* Shutdown procedure */
774
775
mandos_end:
776
free(buffer);
777
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
778
if(ret == -1){
779
perror("close");
780
}
781
gnutls_deinit(session);
782
return retval;
783
}
784
785
static void resolve_callback(AvahiSServiceResolver *r,
786
AvahiIfIndex interface,
787
AvahiProtocol proto,
788
AvahiResolverEvent event,
789
const char *name,
790
const char *type,
791
const char *domain,
792
const char *host_name,
793
const AvahiAddress *address,
794
uint16_t port,
795
AVAHI_GCC_UNUSED AvahiStringList *txt,
796
AVAHI_GCC_UNUSED AvahiLookupResultFlags
797
flags,
798
AVAHI_GCC_UNUSED void* userdata){
799
assert(r);
800
801
/* Called whenever a service has been resolved successfully or
802
timed out */
803
804
switch(event){
805
default:
806
case AVAHI_RESOLVER_FAILURE:
807
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
808
" of type '%s' in domain '%s': %s\n", name, type, domain,
809
avahi_strerror(avahi_server_errno(mc.server)));
810
break;
811
812
case AVAHI_RESOLVER_FOUND:
813
{
814
char ip[AVAHI_ADDRESS_STR_MAX];
815
avahi_address_snprint(ip, sizeof(ip), address);
816
if(debug){
817
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
818
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
819
ip, (intmax_t)interface, port);
820
}
821
int ret = start_mandos_communication(ip, port, interface,
822
avahi_proto_to_af(proto));
823
if(ret == 0){
824
avahi_simple_poll_quit(mc.simple_poll);
825
}
826
}
827
}
828
avahi_s_service_resolver_free(r);
829
}
830
831
static void browse_callback(AvahiSServiceBrowser *b,
832
AvahiIfIndex interface,
833
AvahiProtocol protocol,
834
AvahiBrowserEvent event,
835
const char *name,
836
const char *type,
837
const char *domain,
838
AVAHI_GCC_UNUSED AvahiLookupResultFlags
839
flags,
840
AVAHI_GCC_UNUSED void* userdata){
841
assert(b);
842
843
/* Called whenever a new services becomes available on the LAN or
844
is removed from the LAN */
845
846
switch(event){
847
default:
848
case AVAHI_BROWSER_FAILURE:
849
850
fprintf(stderr, "(Avahi browser) %s\n",
851
avahi_strerror(avahi_server_errno(mc.server)));
852
avahi_simple_poll_quit(mc.simple_poll);
853
return;
854
855
case AVAHI_BROWSER_NEW:
856
/* We ignore the returned Avahi resolver object. In the callback
857
function we free it. If the Avahi server is terminated before
858
the callback function is called the Avahi server will free the
859
resolver for us. */
860
861
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
862
name, type, domain, protocol, 0,
863
resolve_callback, NULL) == NULL)
864
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
865
name, avahi_strerror(avahi_server_errno(mc.server)));
866
break;
867
868
case AVAHI_BROWSER_REMOVE:
869
break;
870
871
case AVAHI_BROWSER_ALL_FOR_NOW:
872
case AVAHI_BROWSER_CACHE_EXHAUSTED:
873
if(debug){
874
fprintf(stderr, "No Mandos server found, still searching...\n");
875
}
876
break;
877
}
878
}
879
880
sig_atomic_t quit_now = 0;
881
882
/* stop main loop after sigterm has been called */
883
static void handle_sigterm(__attribute__((unused)) int sig){
884
if(quit_now){
885
return;
886
}
887
quit_now = 1;
888
int old_errno = errno;
889
if(mc.simple_poll != NULL){
890
avahi_simple_poll_quit(mc.simple_poll);
891
}
892
errno = old_errno;
893
}
894
895
int main(int argc, char *argv[]){
896
AvahiSServiceBrowser *sb = NULL;
897
int error;
898
int ret;
899
intmax_t tmpmax;
900
char *tmp;
901
int exitcode = EXIT_SUCCESS;
902
const char *interface = "eth0";
903
struct ifreq network;
904
int sd;
905
uid_t uid;
906
gid_t gid;
907
char *connect_to = NULL;
908
char tempdir[] = "/tmp/mandosXXXXXX";
909
bool tempdir_created = false;
910
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
911
const char *seckey = PATHDIR "/" SECKEY;
912
const char *pubkey = PATHDIR "/" PUBKEY;
913
914
bool gnutls_initialized = false;
915
bool gpgme_initialized = false;
916
float delay = 2.5f;
917
918
struct sigaction old_sigterm_action;
919
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
920
921
{
922
struct argp_option options[] = {
923
{ .name = "debug", .key = 128,
924
.doc = "Debug mode", .group = 3 },
925
{ .name = "connect", .key = 'c',
926
.arg = "ADDRESS:PORT",
927
.doc = "Connect directly to a specific Mandos server",
928
.group = 1 },
929
{ .name = "interface", .key = 'i',
930
.arg = "NAME",
931
.doc = "Network interface that will be used to search for"
932
" Mandos servers",
933
.group = 1 },
934
{ .name = "seckey", .key = 's',
935
.arg = "FILE",
936
.doc = "OpenPGP secret key file base name",
937
.group = 1 },
938
{ .name = "pubkey", .key = 'p',
939
.arg = "FILE",
940
.doc = "OpenPGP public key file base name",
941
.group = 2 },
942
{ .name = "dh-bits", .key = 129,
943
.arg = "BITS",
944
.doc = "Bit length of the prime number used in the"
945
" Diffie-Hellman key exchange",
946
.group = 2 },
947
{ .name = "priority", .key = 130,
948
.arg = "STRING",
949
.doc = "GnuTLS priority string for the TLS handshake",
950
.group = 1 },
951
{ .name = "delay", .key = 131,
952
.arg = "SECONDS",
953
.doc = "Maximum delay to wait for interface startup",
954
.group = 2 },
955
{ .name = NULL }
956
};
957
958
error_t parse_opt(int key, char *arg,
959
struct argp_state *state){
960
switch(key){
961
case 128: /* --debug */
962
debug = true;
963
break;
964
case 'c': /* --connect */
965
connect_to = arg;
966
break;
967
case 'i': /* --interface */
968
interface = arg;
969
break;
970
case 's': /* --seckey */
971
seckey = arg;
972
break;
973
case 'p': /* --pubkey */
974
pubkey = arg;
975
break;
976
case 129: /* --dh-bits */
977
errno = 0;
978
tmpmax = strtoimax(arg, &tmp, 10);
979
if(errno != 0 or tmp == arg or *tmp != '\0'
980
or tmpmax != (typeof(mc.dh_bits))tmpmax){
981
fprintf(stderr, "Bad number of DH bits\n");
982
exit(EXIT_FAILURE);
983
}
984
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
985
break;
986
case 130: /* --priority */
987
mc.priority = arg;
988
break;
989
case 131: /* --delay */
990
errno = 0;
991
delay = strtof(arg, &tmp);
992
if(errno != 0 or tmp == arg or *tmp != '\0'){
993
fprintf(stderr, "Bad delay\n");
994
exit(EXIT_FAILURE);
995
}
996
break;
997
case ARGP_KEY_ARG:
998
argp_usage(state);
999
case ARGP_KEY_END:
1000
break;
1001
default:
1002
return ARGP_ERR_UNKNOWN;
1003
}
1004
return 0;
1005
}
1006
1007
struct argp argp = { .options = options, .parser = parse_opt,
1008
.args_doc = "",
1009
.doc = "Mandos client -- Get and decrypt"
1010
" passwords from a Mandos server" };
1011
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1012
if(ret == ARGP_ERR_UNKNOWN){
1013
fprintf(stderr, "Unknown error while parsing arguments\n");
1014
exitcode = EXIT_FAILURE;
1015
goto end;
1016
}
1017
}
1018
1019
if(not debug){
1020
avahi_set_log_function(empty_log);
1021
}
1022
1023
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1024
from the signal handler */
1025
/* Initialize the pseudo-RNG for Avahi */
1026
srand((unsigned int) time(NULL));
1027
mc.simple_poll = avahi_simple_poll_new();
1028
if(mc.simple_poll == NULL){
1029
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1030
exitcode = EXIT_FAILURE;
1031
goto end;
1032
}
1033
1034
sigemptyset(&sigterm_action.sa_mask);
1035
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1036
if(ret == -1){
1037
perror("sigaddset");
1038
exitcode = EXIT_FAILURE;
1039
goto end;
1040
}
1041
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1042
if(ret == -1){
1043
perror("sigaddset");
1044
exitcode = EXIT_FAILURE;
1045
goto end;
1046
}
1047
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1048
if(ret == -1){
1049
perror("sigaddset");
1050
exitcode = EXIT_FAILURE;
1051
goto end;
1052
}
1053
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1054
if(ret == -1){
1055
perror("sigaction");
1056
exitcode = EXIT_FAILURE;
1057
goto end;
1058
}
1059
1060
/* If the interface is down, bring it up */
1061
if(interface[0] != '\0'){
1062
#ifdef __linux__
1063
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1064
messages to mess up the prompt */
1065
ret = klogctl(8, NULL, 5);
1066
bool restore_loglevel = true;
1067
if(ret == -1){
1068
restore_loglevel = false;
1069
perror("klogctl");
1070
}
1071
#endif /* __linux__ */
1072
1073
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1074
if(sd < 0){
1075
perror("socket");
1076
exitcode = EXIT_FAILURE;
1077
#ifdef __linux__
1078
if(restore_loglevel){
1079
ret = klogctl(7, NULL, 0);
1080
if(ret == -1){
1081
perror("klogctl");
1082
}
1083
}
1084
#endif /* __linux__ */
1085
goto end;
1086
}
1087
strcpy(network.ifr_name, interface);
1088
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1089
if(ret == -1){
1090
perror("ioctl SIOCGIFFLAGS");
1091
#ifdef __linux__
1092
if(restore_loglevel){
1093
ret = klogctl(7, NULL, 0);
1094
if(ret == -1){
1095
perror("klogctl");
1096
}
1097
}
1098
#endif /* __linux__ */
1099
exitcode = EXIT_FAILURE;
1100
goto end;
1101
}
1102
if((network.ifr_flags & IFF_UP) == 0){
1103
network.ifr_flags |= IFF_UP;
1104
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1105
if(ret == -1){
1106
perror("ioctl SIOCSIFFLAGS");
1107
exitcode = EXIT_FAILURE;
1108
#ifdef __linux__
1109
if(restore_loglevel){
1110
ret = klogctl(7, NULL, 0);
1111
if(ret == -1){
1112
perror("klogctl");
1113
}
1114
}
1115
#endif /* __linux__ */
1116
goto end;
1117
}
1118
}
1119
/* sleep checking until interface is running */
1120
for(int i=0; i < delay * 4; i++){
1121
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1122
if(ret == -1){
1123
perror("ioctl SIOCGIFFLAGS");
1124
} else if(network.ifr_flags & IFF_RUNNING){
1125
break;
1126
}
1127
struct timespec sleeptime = { .tv_nsec = 250000000 };
1128
ret = nanosleep(&sleeptime, NULL);
1129
if(ret == -1 and errno != EINTR){
1130
perror("nanosleep");
1131
}
1132
}
1133
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1134
if(ret == -1){
1135
perror("close");
1136
}
1137
#ifdef __linux__
1138
if(restore_loglevel){
1139
/* Restores kernel loglevel to default */
1140
ret = klogctl(7, NULL, 0);
1141
if(ret == -1){
1142
perror("klogctl");
1143
}
1144
}
1145
#endif /* __linux__ */
1146
}
1147
1148
uid = getuid();
1149
gid = getgid();
1150
1151
errno = 0;
1152
setgid(gid);
1153
if(ret == -1){
1154
perror("setgid");
1155
}
1156
1157
ret = setuid(uid);
1158
if(ret == -1){
1159
perror("setuid");
1160
}
1161
1162
ret = init_gnutls_global(pubkey, seckey);
1163
if(ret == -1){
1164
fprintf(stderr, "init_gnutls_global failed\n");
1165
exitcode = EXIT_FAILURE;
1166
goto end;
1167
} else {
1168
gnutls_initialized = true;
1169
}
1170
1171
if(mkdtemp(tempdir) == NULL){
1172
perror("mkdtemp");
1173
goto end;
1174
}
1175
tempdir_created = true;
1176
1177
if(not init_gpgme(pubkey, seckey, tempdir)){
1178
fprintf(stderr, "init_gpgme failed\n");
1179
exitcode = EXIT_FAILURE;
1180
goto end;
1181
} else {
1182
gpgme_initialized = true;
1183
}
1184
1185
if(interface[0] != '\0'){
1186
if_index = (AvahiIfIndex) if_nametoindex(interface);
1187
if(if_index == 0){
1188
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1189
exitcode = EXIT_FAILURE;
1190
goto end;
1191
}
1192
}
1193
1194
if(connect_to != NULL){
1195
/* Connect directly, do not use Zeroconf */
1196
/* (Mainly meant for debugging) */
1197
char *address = strrchr(connect_to, ':');
1198
if(address == NULL){
1199
fprintf(stderr, "No colon in address\n");
1200
exitcode = EXIT_FAILURE;
1201
goto end;
1202
}
1203
uint16_t port;
1204
errno = 0;
1205
tmpmax = strtoimax(address+1, &tmp, 10);
1206
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1207
or tmpmax != (uint16_t)tmpmax){
1208
fprintf(stderr, "Bad port number\n");
1209
exitcode = EXIT_FAILURE;
1210
goto end;
1211
}
1212
port = (uint16_t)tmpmax;
1213
*address = '\0';
1214
address = connect_to;
1215
/* Colon in address indicates IPv6 */
1216
int af;
1217
if(strchr(address, ':') != NULL){
1218
af = AF_INET6;
1219
} else {
1220
af = AF_INET;
1221
}
1222
ret = start_mandos_communication(address, port, if_index, af);
1223
if(ret < 0){
1224
exitcode = EXIT_FAILURE;
1225
} else {
1226
exitcode = EXIT_SUCCESS;
1227
}
1228
goto end;
1229
}
1230
1231
{
1232
AvahiServerConfig config;
1233
/* Do not publish any local Zeroconf records */
1234
avahi_server_config_init(&config);
1235
config.publish_hinfo = 0;
1236
config.publish_addresses = 0;
1237
config.publish_workstation = 0;
1238
config.publish_domain = 0;
1239
1240
/* Allocate a new server */
1241
mc.server = avahi_server_new(avahi_simple_poll_get
1242
(mc.simple_poll), &config, NULL,
1243
NULL, &error);
1244
1245
/* Free the Avahi configuration data */
1246
avahi_server_config_free(&config);
1247
}
1248
1249
/* Check if creating the Avahi server object succeeded */
1250
if(mc.server == NULL){
1251
fprintf(stderr, "Failed to create Avahi server: %s\n",
1252
avahi_strerror(error));
1253
exitcode = EXIT_FAILURE;
1254
goto end;
1255
}
1256
1257
/* Create the Avahi service browser */
1258
sb = avahi_s_service_browser_new(mc.server, if_index,
1259
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1260
NULL, 0, browse_callback, NULL);
1261
if(sb == NULL){
1262
fprintf(stderr, "Failed to create service browser: %s\n",
1263
avahi_strerror(avahi_server_errno(mc.server)));
1264
exitcode = EXIT_FAILURE;
1265
goto end;
1266
}
1267
1268
/* Run the main loop */
1269
1270
if(debug){
1271
fprintf(stderr, "Starting Avahi loop search\n");
1272
}
1273
1274
avahi_simple_poll_loop(mc.simple_poll);
1275
1276
end:
1277
1278
if(debug){
1279
fprintf(stderr, "%s exiting\n", argv[0]);
1280
}
1281
1282
/* Cleanup things */
1283
if(sb != NULL)
1284
avahi_s_service_browser_free(sb);
1285
1286
if(mc.server != NULL)
1287
avahi_server_free(mc.server);
1288
1289
if(mc.simple_poll != NULL)
1290
avahi_simple_poll_free(mc.simple_poll);
1291
1292
if(gnutls_initialized){
1293
gnutls_certificate_free_credentials(mc.cred);
1294
gnutls_global_deinit();
1295
gnutls_dh_params_deinit(mc.dh_params);
1296
}
1297
1298
if(gpgme_initialized){
1299
gpgme_release(mc.ctx);
1300
}
1301
1302
/* Removes the temp directory used by GPGME */
1303
if(tempdir_created){
1304
DIR *d;
1305
struct dirent *direntry;
1306
d = opendir(tempdir);
1307
if(d == NULL){
1308
if(errno != ENOENT){
1309
perror("opendir");
1310
}
1311
} else {
1312
while(true){
1313
direntry = readdir(d);
1314
if(direntry == NULL){
1315
break;
1316
}
1317
/* Skip "." and ".." */
1318
if(direntry->d_name[0] == '.'
1319
and (direntry->d_name[1] == '\0'
1320
or (direntry->d_name[1] == '.'
1321
and direntry->d_name[2] == '\0'))){
1322
continue;
1323
}
1324
char *fullname = NULL;
1325
ret = asprintf(&fullname, "%s/%s", tempdir,
1326
direntry->d_name);
1327
if(ret < 0){
1328
perror("asprintf");
1329
continue;
1330
}
1331
ret = remove(fullname);
1332
if(ret == -1){
1333
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1334
strerror(errno));
1335
}
1336
free(fullname);
1337
}
1338
closedir(d);
1339
}
1340
ret = rmdir(tempdir);
1341
if(ret == -1 and errno != ENOENT){
1342
perror("rmdir");
1343
}
1344
}
1345
1346
return exitcode;
1347
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0