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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
while(recipient != NULL){
313
fprintf(stderr, "Public key algorithm: %s\n",
314
gpgme_pubkey_algo_name(recipient->pubkey_algo));
315
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
316
fprintf(stderr, "Secret key available: %s\n",
317
recipient->status == GPG_ERR_NO_SECKEY
318
? "No" : "Yes");
319
recipient = recipient->next;
320
}
321
}
322
}
323
goto decrypt_end;
324
}
325
326
if(debug){
327
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
328
}
329
330
/* Seek back to the beginning of the GPGME plaintext data buffer */
331
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
332
perror("gpgme_data_seek");
333
plaintext_length = -1;
334
goto decrypt_end;
335
}
336
337
*plaintext = NULL;
338
while(true){
339
plaintext_capacity = incbuffer(plaintext,
340
(size_t)plaintext_length,
341
plaintext_capacity);
342
if(plaintext_capacity == 0){
343
perror("incbuffer");
344
plaintext_length = -1;
345
goto decrypt_end;
346
}
347
348
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
349
BUFFER_SIZE);
350
/* Print the data, if any */
351
if(ret == 0){
352
/* EOF */
353
break;
354
}
355
if(ret < 0){
356
perror("gpgme_data_read");
357
plaintext_length = -1;
358
goto decrypt_end;
359
}
360
plaintext_length += ret;
361
}
362
363
if(debug){
364
fprintf(stderr, "Decrypted password is: ");
365
for(ssize_t i = 0; i < plaintext_length; i++){
366
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
367
}
368
fprintf(stderr, "\n");
369
}
370
371
decrypt_end:
372
373
/* Delete the GPGME cryptotext data buffer */
374
gpgme_data_release(dh_crypto);
375
376
/* Delete the GPGME plaintext data buffer */
377
gpgme_data_release(dh_plain);
378
return plaintext_length;
379
}
380
381
static const char * safer_gnutls_strerror(int value){
382
const char *ret = gnutls_strerror(value); /* Spurious warning from
383
-Wunreachable-code */
384
if(ret == NULL)
385
ret = "(unknown)";
386
return ret;
387
}
388
389
/* GnuTLS log function callback */
390
static void debuggnutls(__attribute__((unused)) int level,
391
const char* string){
392
fprintf(stderr, "GnuTLS: %s", string);
393
}
394
395
static int init_gnutls_global(const char *pubkeyfilename,
396
const char *seckeyfilename){
397
int ret;
398
399
if(debug){
400
fprintf(stderr, "Initializing GnuTLS\n");
401
}
402
403
ret = gnutls_global_init();
404
if(ret != GNUTLS_E_SUCCESS){
405
fprintf(stderr, "GnuTLS global_init: %s\n",
406
safer_gnutls_strerror(ret));
407
return -1;
408
}
409
410
if(debug){
411
/* "Use a log level over 10 to enable all debugging options."
412
* - GnuTLS manual
413
*/
414
gnutls_global_set_log_level(11);
415
gnutls_global_set_log_function(debuggnutls);
416
}
417
418
/* OpenPGP credentials */
419
gnutls_certificate_allocate_credentials(&mc.cred);
420
if(ret != GNUTLS_E_SUCCESS){
421
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
422
from
423
-Wunreachable-code
424
*/
425
safer_gnutls_strerror(ret));
426
gnutls_global_deinit();
427
return -1;
428
}
429
430
if(debug){
431
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
432
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
433
seckeyfilename);
434
}
435
436
ret = gnutls_certificate_set_openpgp_key_file
437
(mc.cred, pubkeyfilename, seckeyfilename,
438
GNUTLS_OPENPGP_FMT_BASE64);
439
if(ret != GNUTLS_E_SUCCESS){
440
fprintf(stderr,
441
"Error[%d] while reading the OpenPGP key pair ('%s',"
442
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
443
fprintf(stderr, "The GnuTLS error is: %s\n",
444
safer_gnutls_strerror(ret));
445
goto globalfail;
446
}
447
448
/* GnuTLS server initialization */
449
ret = gnutls_dh_params_init(&mc.dh_params);
450
if(ret != GNUTLS_E_SUCCESS){
451
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
452
" %s\n", safer_gnutls_strerror(ret));
453
goto globalfail;
454
}
455
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
456
if(ret != GNUTLS_E_SUCCESS){
457
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
458
safer_gnutls_strerror(ret));
459
goto globalfail;
460
}
461
462
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
463
464
return 0;
465
466
globalfail:
467
468
gnutls_certificate_free_credentials(mc.cred);
469
gnutls_global_deinit();
470
gnutls_dh_params_deinit(mc.dh_params);
471
return -1;
472
}
473
474
static int init_gnutls_session(gnutls_session_t *session){
475
int ret;
476
/* GnuTLS session creation */
477
ret = gnutls_init(session, GNUTLS_SERVER);
478
if(ret != GNUTLS_E_SUCCESS){
479
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
480
safer_gnutls_strerror(ret));
481
}
482
483
{
484
const char *err;
485
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
486
if(ret != GNUTLS_E_SUCCESS){
487
fprintf(stderr, "Syntax error at: %s\n", err);
488
fprintf(stderr, "GnuTLS error: %s\n",
489
safer_gnutls_strerror(ret));
490
gnutls_deinit(*session);
491
return -1;
492
}
493
}
494
495
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
496
mc.cred);
497
if(ret != GNUTLS_E_SUCCESS){
498
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
499
safer_gnutls_strerror(ret));
500
gnutls_deinit(*session);
501
return -1;
502
}
503
504
/* ignore client certificate if any. */
505
gnutls_certificate_server_set_request(*session,
506
GNUTLS_CERT_IGNORE);
507
508
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
509
510
return 0;
511
}
512
513
/* Avahi log function callback */
514
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
515
__attribute__((unused)) const char *txt){}
516
517
/* Called when a Mandos server is found */
518
static int start_mandos_communication(const char *ip, uint16_t port,
519
AvahiIfIndex if_index,
520
int af){
521
int ret, tcp_sd;
522
ssize_t sret;
523
union {
524
struct sockaddr_in in;
525
struct sockaddr_in6 in6;
526
} to;
527
char *buffer = NULL;
528
char *decrypted_buffer;
529
size_t buffer_length = 0;
530
size_t buffer_capacity = 0;
531
ssize_t decrypted_buffer_size;
532
size_t written;
533
int retval = 0;
534
gnutls_session_t session;
535
int pf; /* Protocol family */
536
537
switch(af){
538
case AF_INET6:
539
pf = PF_INET6;
540
break;
541
case AF_INET:
542
pf = PF_INET;
543
break;
544
default:
545
fprintf(stderr, "Bad address family: %d\n", af);
546
return -1;
547
}
548
549
ret = init_gnutls_session(&session);
550
if(ret != 0){
551
return -1;
552
}
553
554
if(debug){
555
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
556
"\n", ip, port);
557
}
558
559
tcp_sd = socket(pf, SOCK_STREAM, 0);
560
if(tcp_sd < 0){
561
perror("socket");
562
return -1;
563
}
564
565
memset(&to, 0, sizeof(to));
566
if(af == AF_INET6){
567
to.in6.sin6_family = (sa_family_t)af;
568
ret = inet_pton(af, ip, &to.in6.sin6_addr);
569
} else { /* IPv4 */
570
to.in.sin_family = (sa_family_t)af;
571
ret = inet_pton(af, ip, &to.in.sin_addr);
572
}
573
if(ret < 0 ){
574
perror("inet_pton");
575
return -1;
576
}
577
if(ret == 0){
578
fprintf(stderr, "Bad address: %s\n", ip);
579
return -1;
580
}
581
if(af == AF_INET6){
582
to.in6.sin6_port = htons(port); /* Spurious warnings from
583
-Wconversion and
584
-Wunreachable-code */
585
586
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
587
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
588
-Wunreachable-code*/
589
if(if_index == AVAHI_IF_UNSPEC){
590
fprintf(stderr, "An IPv6 link-local address is incomplete"
591
" without a network interface\n");
592
return -1;
593
}
594
/* Set the network interface number as scope */
595
to.in6.sin6_scope_id = (uint32_t)if_index;
596
}
597
} else {
598
to.in.sin_port = htons(port); /* Spurious warnings from
599
-Wconversion and
600
-Wunreachable-code */
601
}
602
603
if(debug){
604
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
605
char interface[IF_NAMESIZE];
606
if(if_indextoname((unsigned int)if_index, interface) == NULL){
607
perror("if_indextoname");
608
} else {
609
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
610
ip, interface, port);
611
}
612
} else {
613
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
614
port);
615
}
616
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
617
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
618
const char *pcret;
619
if(af == AF_INET6){
620
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
621
sizeof(addrstr));
622
} else {
623
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
624
sizeof(addrstr));
625
}
626
if(pcret == NULL){
627
perror("inet_ntop");
628
} else {
629
if(strcmp(addrstr, ip) != 0){
630
fprintf(stderr, "Canonical address form: %s\n", addrstr);
631
}
632
}
633
}
634
635
if(af == AF_INET6){
636
ret = connect(tcp_sd, &to.in6, sizeof(to));
637
} else {
638
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
639
}
640
if(ret < 0){
641
perror("connect");
642
return -1;
643
}
644
645
const char *out = mandos_protocol_version;
646
written = 0;
647
while(true){
648
size_t out_size = strlen(out);
649
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
650
out_size - written));
651
if(ret == -1){
652
perror("write");
653
retval = -1;
654
goto mandos_end;
655
}
656
written += (size_t)ret;
657
if(written < out_size){
658
continue;
659
} else {
660
if(out == mandos_protocol_version){
661
written = 0;
662
out = "\r\n";
663
} else {
664
break;
665
}
666
}
667
}
668
669
if(debug){
670
fprintf(stderr, "Establishing TLS session with %s\n", ip);
671
}
672
673
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
674
675
do{
676
ret = gnutls_handshake(session);
677
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
678
679
if(ret != GNUTLS_E_SUCCESS){
680
if(debug){
681
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
682
gnutls_perror(ret);
683
}
684
retval = -1;
685
goto mandos_end;
686
}
687
688
/* Read OpenPGP packet that contains the wanted password */
689
690
if(debug){
691
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
692
ip);
693
}
694
695
while(true){
696
buffer_capacity = incbuffer(&buffer, buffer_length,
697
buffer_capacity);
698
if(buffer_capacity == 0){
699
perror("incbuffer");
700
retval = -1;
701
goto mandos_end;
702
}
703
704
sret = gnutls_record_recv(session, buffer+buffer_length,
705
BUFFER_SIZE);
706
if(sret == 0){
707
break;
708
}
709
if(sret < 0){
710
switch(sret){
711
case GNUTLS_E_INTERRUPTED:
712
case GNUTLS_E_AGAIN:
713
break;
714
case GNUTLS_E_REHANDSHAKE:
715
do{
716
ret = gnutls_handshake(session);
717
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
718
if(ret < 0){
719
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
720
gnutls_perror(ret);
721
retval = -1;
722
goto mandos_end;
723
}
724
break;
725
default:
726
fprintf(stderr, "Unknown error while reading data from"
727
" encrypted session with Mandos server\n");
728
retval = -1;
729
gnutls_bye(session, GNUTLS_SHUT_RDWR);
730
goto mandos_end;
731
}
732
} else {
733
buffer_length += (size_t) sret;
734
}
735
}
736
737
if(debug){
738
fprintf(stderr, "Closing TLS session\n");
739
}
740
741
gnutls_bye(session, GNUTLS_SHUT_RDWR);
742
743
if(buffer_length > 0){
744
decrypted_buffer_size = pgp_packet_decrypt(buffer,
745
buffer_length,
746
&decrypted_buffer);
747
if(decrypted_buffer_size >= 0){
748
written = 0;
749
while(written < (size_t) decrypted_buffer_size){
750
ret = (int)fwrite(decrypted_buffer + written, 1,
751
(size_t)decrypted_buffer_size - written,
752
stdout);
753
if(ret == 0 and ferror(stdout)){
754
if(debug){
755
fprintf(stderr, "Error writing encrypted data: %s\n",
756
strerror(errno));
757
}
758
retval = -1;
759
break;
760
}
761
written += (size_t)ret;
762
}
763
free(decrypted_buffer);
764
} else {
765
retval = -1;
766
}
767
} else {
768
retval = -1;
769
}
770
771
/* Shutdown procedure */
772
773
mandos_end:
774
free(buffer);
775
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
776
if(ret == -1){
777
perror("close");
778
}
779
gnutls_deinit(session);
780
return retval;
781
}
782
783
static void resolve_callback(AvahiSServiceResolver *r,
784
AvahiIfIndex interface,
785
AvahiProtocol proto,
786
AvahiResolverEvent event,
787
const char *name,
788
const char *type,
789
const char *domain,
790
const char *host_name,
791
const AvahiAddress *address,
792
uint16_t port,
793
AVAHI_GCC_UNUSED AvahiStringList *txt,
794
AVAHI_GCC_UNUSED AvahiLookupResultFlags
795
flags,
796
AVAHI_GCC_UNUSED void* userdata){
797
assert(r);
798
799
/* Called whenever a service has been resolved successfully or
800
timed out */
801
802
switch(event){
803
default:
804
case AVAHI_RESOLVER_FAILURE:
805
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
806
" of type '%s' in domain '%s': %s\n", name, type, domain,
807
avahi_strerror(avahi_server_errno(mc.server)));
808
break;
809
810
case AVAHI_RESOLVER_FOUND:
811
{
812
char ip[AVAHI_ADDRESS_STR_MAX];
813
avahi_address_snprint(ip, sizeof(ip), address);
814
if(debug){
815
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
816
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
817
ip, (intmax_t)interface, port);
818
}
819
int ret = start_mandos_communication(ip, port, interface,
820
avahi_proto_to_af(proto));
821
if(ret == 0){
822
avahi_simple_poll_quit(mc.simple_poll);
823
}
824
}
825
}
826
avahi_s_service_resolver_free(r);
827
}
828
829
static void browse_callback(AvahiSServiceBrowser *b,
830
AvahiIfIndex interface,
831
AvahiProtocol protocol,
832
AvahiBrowserEvent event,
833
const char *name,
834
const char *type,
835
const char *domain,
836
AVAHI_GCC_UNUSED AvahiLookupResultFlags
837
flags,
838
AVAHI_GCC_UNUSED void* userdata){
839
assert(b);
840
841
/* Called whenever a new services becomes available on the LAN or
842
is removed from the LAN */
843
844
switch(event){
845
default:
846
case AVAHI_BROWSER_FAILURE:
847
848
fprintf(stderr, "(Avahi browser) %s\n",
849
avahi_strerror(avahi_server_errno(mc.server)));
850
avahi_simple_poll_quit(mc.simple_poll);
851
return;
852
853
case AVAHI_BROWSER_NEW:
854
/* We ignore the returned Avahi resolver object. In the callback
855
function we free it. If the Avahi server is terminated before
856
the callback function is called the Avahi server will free the
857
resolver for us. */
858
859
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
860
name, type, domain, protocol, 0,
861
resolve_callback, NULL) == NULL)
862
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
863
name, avahi_strerror(avahi_server_errno(mc.server)));
864
break;
865
866
case AVAHI_BROWSER_REMOVE:
867
break;
868
869
case AVAHI_BROWSER_ALL_FOR_NOW:
870
case AVAHI_BROWSER_CACHE_EXHAUSTED:
871
if(debug){
872
fprintf(stderr, "No Mandos server found, still searching...\n");
873
}
874
break;
875
}
876
}
877
878
sig_atomic_t quit_now = 0;
879
880
/* stop main loop after sigterm has been called */
881
static void handle_sigterm(__attribute__((unused)) int sig){
882
if(quit_now){
883
return;
884
}
885
quit_now = 1;
886
int old_errno = errno;
887
if(mc.simple_poll != NULL){
888
avahi_simple_poll_quit(mc.simple_poll);
889
}
890
errno = old_errno;
891
}
892
893
int main(int argc, char *argv[]){
894
AvahiSServiceBrowser *sb = NULL;
895
int error;
896
int ret;
897
intmax_t tmpmax;
898
char *tmp;
899
int exitcode = EXIT_SUCCESS;
900
const char *interface = "eth0";
901
struct ifreq network;
902
int sd = -1;
903
bool interface_taken_up = false;
904
uid_t uid;
905
gid_t gid;
906
char *connect_to = NULL;
907
char tempdir[] = "/tmp/mandosXXXXXX";
908
bool tempdir_created = false;
909
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
910
const char *seckey = PATHDIR "/" SECKEY;
911
const char *pubkey = PATHDIR "/" PUBKEY;
912
913
bool gnutls_initialized = false;
914
bool gpgme_initialized = false;
915
float delay = 2.5f;
916
917
struct sigaction old_sigterm_action;
918
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
919
920
{
921
struct argp_option options[] = {
922
{ .name = "debug", .key = 128,
923
.doc = "Debug mode", .group = 3 },
924
{ .name = "connect", .key = 'c',
925
.arg = "ADDRESS:PORT",
926
.doc = "Connect directly to a specific Mandos server",
927
.group = 1 },
928
{ .name = "interface", .key = 'i',
929
.arg = "NAME",
930
.doc = "Network interface that will be used to search for"
931
" Mandos servers",
932
.group = 1 },
933
{ .name = "seckey", .key = 's',
934
.arg = "FILE",
935
.doc = "OpenPGP secret key file base name",
936
.group = 1 },
937
{ .name = "pubkey", .key = 'p',
938
.arg = "FILE",
939
.doc = "OpenPGP public key file base name",
940
.group = 2 },
941
{ .name = "dh-bits", .key = 129,
942
.arg = "BITS",
943
.doc = "Bit length of the prime number used in the"
944
" Diffie-Hellman key exchange",
945
.group = 2 },
946
{ .name = "priority", .key = 130,
947
.arg = "STRING",
948
.doc = "GnuTLS priority string for the TLS handshake",
949
.group = 1 },
950
{ .name = "delay", .key = 131,
951
.arg = "SECONDS",
952
.doc = "Maximum delay to wait for interface startup",
953
.group = 2 },
954
{ .name = NULL }
955
};
956
957
error_t parse_opt(int key, char *arg,
958
struct argp_state *state){
959
switch(key){
960
case 128: /* --debug */
961
debug = true;
962
break;
963
case 'c': /* --connect */
964
connect_to = arg;
965
break;
966
case 'i': /* --interface */
967
interface = arg;
968
break;
969
case 's': /* --seckey */
970
seckey = arg;
971
break;
972
case 'p': /* --pubkey */
973
pubkey = arg;
974
break;
975
case 129: /* --dh-bits */
976
errno = 0;
977
tmpmax = strtoimax(arg, &tmp, 10);
978
if(errno != 0 or tmp == arg or *tmp != '\0'
979
or tmpmax != (typeof(mc.dh_bits))tmpmax){
980
fprintf(stderr, "Bad number of DH bits\n");
981
exit(EXIT_FAILURE);
982
}
983
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
984
break;
985
case 130: /* --priority */
986
mc.priority = arg;
987
break;
988
case 131: /* --delay */
989
errno = 0;
990
delay = strtof(arg, &tmp);
991
if(errno != 0 or tmp == arg or *tmp != '\0'){
992
fprintf(stderr, "Bad delay\n");
993
exit(EXIT_FAILURE);
994
}
995
break;
996
case ARGP_KEY_ARG:
997
argp_usage(state);
998
case ARGP_KEY_END:
999
break;
1000
default:
1001
return ARGP_ERR_UNKNOWN;
1002
}
1003
return 0;
1004
}
1005
1006
struct argp argp = { .options = options, .parser = parse_opt,
1007
.args_doc = "",
1008
.doc = "Mandos client -- Get and decrypt"
1009
" passwords from a Mandos server" };
1010
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1011
if(ret == ARGP_ERR_UNKNOWN){
1012
fprintf(stderr, "Unknown error while parsing arguments\n");
1013
exitcode = EXIT_FAILURE;
1014
goto end;
1015
}
1016
}
1017
1018
if(not debug){
1019
avahi_set_log_function(empty_log);
1020
}
1021
1022
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1023
from the signal handler */
1024
/* Initialize the pseudo-RNG for Avahi */
1025
srand((unsigned int) time(NULL));
1026
mc.simple_poll = avahi_simple_poll_new();
1027
if(mc.simple_poll == NULL){
1028
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1029
exitcode = EXIT_FAILURE;
1030
goto end;
1031
}
1032
1033
sigemptyset(&sigterm_action.sa_mask);
1034
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1035
if(ret == -1){
1036
perror("sigaddset");
1037
exitcode = EXIT_FAILURE;
1038
goto end;
1039
}
1040
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1041
if(ret == -1){
1042
perror("sigaddset");
1043
exitcode = EXIT_FAILURE;
1044
goto end;
1045
}
1046
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1047
if(ret == -1){
1048
perror("sigaddset");
1049
exitcode = EXIT_FAILURE;
1050
goto end;
1051
}
1052
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1053
if(ret == -1){
1054
perror("sigaction");
1055
exitcode = EXIT_FAILURE;
1056
goto end;
1057
}
1058
1059
/* If the interface is down, bring it up */
1060
if(interface[0] != '\0'){
1061
#ifdef __linux__
1062
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1063
messages to mess up the prompt */
1064
ret = klogctl(8, NULL, 5);
1065
bool restore_loglevel = true;
1066
if(ret == -1){
1067
restore_loglevel = false;
1068
perror("klogctl");
1069
}
1070
#endif /* __linux__ */
1071
1072
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1073
if(sd < 0){
1074
perror("socket");
1075
exitcode = EXIT_FAILURE;
1076
#ifdef __linux__
1077
if(restore_loglevel){
1078
ret = klogctl(7, NULL, 0);
1079
if(ret == -1){
1080
perror("klogctl");
1081
}
1082
}
1083
#endif /* __linux__ */
1084
goto end;
1085
}
1086
strcpy(network.ifr_name, interface);
1087
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1088
if(ret == -1){
1089
perror("ioctl SIOCGIFFLAGS");
1090
#ifdef __linux__
1091
if(restore_loglevel){
1092
ret = klogctl(7, NULL, 0);
1093
if(ret == -1){
1094
perror("klogctl");
1095
}
1096
}
1097
#endif /* __linux__ */
1098
exitcode = EXIT_FAILURE;
1099
goto end;
1100
}
1101
if((network.ifr_flags & IFF_UP) == 0){
1102
network.ifr_flags |= IFF_UP;
1103
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1104
if(ret == -1){
1105
perror("ioctl SIOCSIFFLAGS");
1106
exitcode = EXIT_FAILURE;
1107
#ifdef __linux__
1108
if(restore_loglevel){
1109
ret = klogctl(7, NULL, 0);
1110
if(ret == -1){
1111
perror("klogctl");
1112
}
1113
}
1114
#endif /* __linux__ */
1115
goto end;
1116
}
1117
interface_taken_up = true;
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
if(not interface_taken_up){
1134
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1135
if(ret == -1){
1136
perror("close");
1137
}
1138
}
1139
#ifdef __linux__
1140
if(restore_loglevel){
1141
/* Restores kernel loglevel to default */
1142
ret = klogctl(7, NULL, 0);
1143
if(ret == -1){
1144
perror("klogctl");
1145
}
1146
}
1147
#endif /* __linux__ */
1148
}
1149
1150
uid = getuid();
1151
gid = getgid();
1152
1153
errno = 0;
1154
setgid(gid);
1155
if(ret == -1){
1156
perror("setgid");
1157
}
1158
1159
ret = setuid(uid);
1160
if(ret == -1){
1161
perror("setuid");
1162
}
1163
1164
ret = init_gnutls_global(pubkey, seckey);
1165
if(ret == -1){
1166
fprintf(stderr, "init_gnutls_global failed\n");
1167
exitcode = EXIT_FAILURE;
1168
goto end;
1169
} else {
1170
gnutls_initialized = true;
1171
}
1172
1173
if(mkdtemp(tempdir) == NULL){
1174
perror("mkdtemp");
1175
goto end;
1176
}
1177
tempdir_created = true;
1178
1179
if(not init_gpgme(pubkey, seckey, tempdir)){
1180
fprintf(stderr, "init_gpgme failed\n");
1181
exitcode = EXIT_FAILURE;
1182
goto end;
1183
} else {
1184
gpgme_initialized = true;
1185
}
1186
1187
if(interface[0] != '\0'){
1188
if_index = (AvahiIfIndex) if_nametoindex(interface);
1189
if(if_index == 0){
1190
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1191
exitcode = EXIT_FAILURE;
1192
goto end;
1193
}
1194
}
1195
1196
if(connect_to != NULL){
1197
/* Connect directly, do not use Zeroconf */
1198
/* (Mainly meant for debugging) */
1199
char *address = strrchr(connect_to, ':');
1200
if(address == NULL){
1201
fprintf(stderr, "No colon in address\n");
1202
exitcode = EXIT_FAILURE;
1203
goto end;
1204
}
1205
uint16_t port;
1206
errno = 0;
1207
tmpmax = strtoimax(address+1, &tmp, 10);
1208
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1209
or tmpmax != (uint16_t)tmpmax){
1210
fprintf(stderr, "Bad port number\n");
1211
exitcode = EXIT_FAILURE;
1212
goto end;
1213
}
1214
port = (uint16_t)tmpmax;
1215
*address = '\0';
1216
address = connect_to;
1217
/* Colon in address indicates IPv6 */
1218
int af;
1219
if(strchr(address, ':') != NULL){
1220
af = AF_INET6;
1221
} else {
1222
af = AF_INET;
1223
}
1224
ret = start_mandos_communication(address, port, if_index, af);
1225
if(ret < 0){
1226
exitcode = EXIT_FAILURE;
1227
} else {
1228
exitcode = EXIT_SUCCESS;
1229
}
1230
goto end;
1231
}
1232
1233
{
1234
AvahiServerConfig config;
1235
/* Do not publish any local Zeroconf records */
1236
avahi_server_config_init(&config);
1237
config.publish_hinfo = 0;
1238
config.publish_addresses = 0;
1239
config.publish_workstation = 0;
1240
config.publish_domain = 0;
1241
1242
/* Allocate a new server */
1243
mc.server = avahi_server_new(avahi_simple_poll_get
1244
(mc.simple_poll), &config, NULL,
1245
NULL, &error);
1246
1247
/* Free the Avahi configuration data */
1248
avahi_server_config_free(&config);
1249
}
1250
1251
/* Check if creating the Avahi server object succeeded */
1252
if(mc.server == NULL){
1253
fprintf(stderr, "Failed to create Avahi server: %s\n",
1254
avahi_strerror(error));
1255
exitcode = EXIT_FAILURE;
1256
goto end;
1257
}
1258
1259
/* Create the Avahi service browser */
1260
sb = avahi_s_service_browser_new(mc.server, if_index,
1261
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1262
NULL, 0, browse_callback, NULL);
1263
if(sb == NULL){
1264
fprintf(stderr, "Failed to create service browser: %s\n",
1265
avahi_strerror(avahi_server_errno(mc.server)));
1266
exitcode = EXIT_FAILURE;
1267
goto end;
1268
}
1269
1270
/* Run the main loop */
1271
1272
if(debug){
1273
fprintf(stderr, "Starting Avahi loop search\n");
1274
}
1275
1276
avahi_simple_poll_loop(mc.simple_poll);
1277
1278
end:
1279
1280
if(debug){
1281
fprintf(stderr, "%s exiting\n", argv[0]);
1282
}
1283
1284
/* Cleanup things */
1285
if(sb != NULL)
1286
avahi_s_service_browser_free(sb);
1287
1288
if(mc.server != NULL)
1289
avahi_server_free(mc.server);
1290
1291
if(mc.simple_poll != NULL)
1292
avahi_simple_poll_free(mc.simple_poll);
1293
1294
if(gnutls_initialized){
1295
gnutls_certificate_free_credentials(mc.cred);
1296
gnutls_global_deinit();
1297
gnutls_dh_params_deinit(mc.dh_params);
1298
}
1299
1300
if(gpgme_initialized){
1301
gpgme_release(mc.ctx);
1302
}
1303
1304
/* Take down the network interface */
1305
if(interface_taken_up){
1306
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1307
if(ret == -1){
1308
perror("ioctl SIOCGIFFLAGS");
1309
} else if(network.ifr_flags & IFF_UP) {
1310
network.ifr_flags &= ~IFF_UP; /* clear flag */
1311
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1312
if(ret == -1){
1313
perror("ioctl SIOCSIFFLAGS");
1314
}
1315
}
1316
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1317
if(ret == -1){
1318
perror("close");
1319
}
1320
}
1321
1322
/* Removes the temp directory used by GPGME */
1323
if(tempdir_created){
1324
DIR *d;
1325
struct dirent *direntry;
1326
d = opendir(tempdir);
1327
if(d == NULL){
1328
if(errno != ENOENT){
1329
perror("opendir");
1330
}
1331
} else {
1332
while(true){
1333
direntry = readdir(d);
1334
if(direntry == NULL){
1335
break;
1336
}
1337
/* Skip "." and ".." */
1338
if(direntry->d_name[0] == '.'
1339
and (direntry->d_name[1] == '\0'
1340
or (direntry->d_name[1] == '.'
1341
and direntry->d_name[2] == '\0'))){
1342
continue;
1343
}
1344
char *fullname = NULL;
1345
ret = asprintf(&fullname, "%s/%s", tempdir,
1346
direntry->d_name);
1347
if(ret < 0){
1348
perror("asprintf");
1349
continue;
1350
}
1351
ret = remove(fullname);
1352
if(ret == -1){
1353
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1354
strerror(errno));
1355
}
1356
free(fullname);
1357
}
1358
closedir(d);
1359
}
1360
ret = rmdir(tempdir);
1361
if(ret == -1 and errno != ENOENT){
1362
perror("rmdir");
1363
}
1364
}
1365
1366
return exitcode;
1367
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0