To get this branch, use:
bzr branch
http://bzr.recompile.se/loggerhead/mandos/release
« back to all changes in this revision
Viewing changes to plugins.d/mandos-client.c
- browse files at revision 181
- compare with another revision
- download diff
- download tarball
- view history from revision 181
- Committer: Teddy Hogeborn
- Date: 2008-09-08 18:54:47 UTC
- Revision ID: teddy@fukt.bsnet.se-20080908185447-dm2ertwxa20qbckf
* INSTALL: Even better text.
- files added:
- .bzrignore
- plugins.d
- files removed:
- bad-ca.pem
- 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 © 2007-2008 Teddy Hogeborn & Björn Påhlsson
13
*
14
* This program is free software: you can redistribute it and/or
15
* modify it under the terms of the GNU General Public License as
16
* published by the Free Software Foundation, either version 3 of the
17
* License, or (at your option) any later version.
18
*
19
* This program is distributed in the hope that it will be useful, but
20
* WITHOUT ANY WARRANTY; without even the implied warranty of
21
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22
* General Public License for more details.
23
*
24
* You should have received a copy of the GNU General Public License
25
* along with this program. If not, see
26
* <http://www.gnu.org/licenses/>.
27
*
28
* Contact the authors at <mandos@fukt.bsnet.se>.
29
*/
30
31
/* Needed by GPGME, specifically gpgme_data_seek() */
32
#define _LARGEFILE_SOURCE
33
#define _FILE_OFFSET_BITS 64
34
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
36
37
#include <stdio.h> /* fprintf(), stderr, fwrite(),
38
stdout, ferror() */
39
#include <stdint.h> /* uint16_t, uint32_t */
40
#include <stddef.h> /* NULL, size_t, ssize_t */
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
42
srand() */
43
#include <stdbool.h> /* bool, true */
44
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), asprintf(), strcpy() */
46
#include <sys/ioctl.h> /* ioctl */
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
sockaddr_in6, PF_INET6,
49
SOCK_STREAM, INET6_ADDRSTRLEN,
50
uid_t, gid_t, open(), opendir(), DIR */
51
#include <sys/stat.h> /* open() */
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
struct in6_addr, inet_pton(),
54
connect() */
55
#include <fcntl.h> /* open() */
56
#include <dirent.h> /* opendir(), struct dirent, readdir() */
57
#include <inttypes.h> /* PRIu16 */
58
#include <assert.h> /* assert() */
59
#include <errno.h> /* perror(), errno */
60
#include <time.h> /* time() */
61
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
62
SIOCSIFFLAGS, if_indextoname(),
63
if_nametoindex(), IF_NAMESIZE */
64
#include <netinet/in.h>
65
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
66
getuid(), getgid(), setuid(),
67
setgid() */
68
#include <arpa/inet.h> /* inet_pton(), htons */
69
#include <iso646.h> /* not, and */
70
#include <argp.h> /* struct argp_option, error_t, struct
71
argp_state, struct argp,
72
argp_parse(), ARGP_KEY_ARG,
73
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
74
75
/* Avahi */
76
/* All Avahi types, constants and functions
77
Avahi*, avahi_*,
78
AVAHI_* */
79
#include <avahi-core/core.h>
80
#include <avahi-core/lookup.h>
81
#include <avahi-core/log.h>
82
#include <avahi-common/simple-watch.h>
83
#include <avahi-common/malloc.h>
84
#include <avahi-common/error.h>
85
86
/* GnuTLS */
87
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
88
functions:
89
gnutls_*
90
init_gnutls_session(),
91
GNUTLS_* */
92
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
93
GNUTLS_OPENPGP_FMT_BASE64 */
94
95
/* GPGME */
96
#include <gpgme.h> /* All GPGME types, constants and
97
functions:
98
gpgme_*
99
GPGME_PROTOCOL_OpenPGP,
100
GPG_ERR_NO_* */
101
102
#define BUFFER_SIZE 256
103
104
/*
105
#define PATHDIR "/conf/conf.d/mandos"
106
*/
107
108
#define PATHDIR "/conf/conf.d/mandos"
109
#define SECKEY "seckey.txt"
110
#define PUBKEY "pubkey.txt"
111
112
bool debug = false;
113
static const char mandos_protocol_version[] = "1";
114
const char *argp_program_version = "mandos-client 1.0";
115
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
116
117
/* Used for passing in values through the Avahi callback functions */
118
typedef struct {
119
AvahiSimplePoll *simple_poll;
120
AvahiServer *server;
121
gnutls_certificate_credentials_t cred;
122
unsigned int dh_bits;
123
gnutls_dh_params_t dh_params;
124
const char *priority;
125
gpgme_ctx_t ctx;
126
} mandos_context;
127
128
/*
129
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
130
* "buffer_capacity" is how much is currently allocated,
131
* "buffer_length" is how much is already used.
132
*/
133
size_t adjustbuffer(char **buffer, size_t buffer_length,
134
size_t buffer_capacity){
135
if (buffer_length + BUFFER_SIZE > buffer_capacity){
136
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
137
if (buffer == NULL){
138
return 0;
139
}
140
buffer_capacity += BUFFER_SIZE;
141
}
142
return buffer_capacity;
143
}
144
145
/*
146
* Initialize GPGME.
147
*/
148
static bool init_gpgme(mandos_context *mc, const char *seckey,
149
const char *pubkey, const char *tempdir){
150
int ret;
151
gpgme_error_t rc;
152
gpgme_engine_info_t engine_info;
153
154
155
/*
156
* Helper function to insert pub and seckey to the enigne keyring.
157
*/
158
bool import_key(const char *filename){
159
int fd;
160
gpgme_data_t pgp_data;
161
162
fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
163
if(fd == -1){
164
perror("open");
165
return false;
166
}
167
168
rc = gpgme_data_new_from_fd(&pgp_data, fd);
169
if (rc != GPG_ERR_NO_ERROR){
170
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
171
gpgme_strsource(rc), gpgme_strerror(rc));
172
return false;
173
}
174
175
rc = gpgme_op_import(mc->ctx, pgp_data);
176
if (rc != GPG_ERR_NO_ERROR){
177
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
178
gpgme_strsource(rc), gpgme_strerror(rc));
179
return false;
180
}
181
182
ret = TEMP_FAILURE_RETRY(close(fd));
183
if(ret == -1){
184
perror("close");
185
}
186
gpgme_data_release(pgp_data);
187
return true;
188
}
189
190
if (debug){
191
fprintf(stderr, "Initialize gpgme\n");
192
}
193
194
/* Init GPGME */
195
gpgme_check_version(NULL);
196
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
197
if (rc != GPG_ERR_NO_ERROR){
198
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
199
gpgme_strsource(rc), gpgme_strerror(rc));
200
return false;
201
}
202
203
/* Set GPGME home directory for the OpenPGP engine only */
204
rc = gpgme_get_engine_info (&engine_info);
205
if (rc != GPG_ERR_NO_ERROR){
206
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
207
gpgme_strsource(rc), gpgme_strerror(rc));
208
return false;
209
}
210
while(engine_info != NULL){
211
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
212
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
213
engine_info->file_name, tempdir);
214
break;
215
}
216
engine_info = engine_info->next;
217
}
218
if(engine_info == NULL){
219
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
220
return false;
221
}
222
223
/* Create new GPGME "context" */
224
rc = gpgme_new(&(mc->ctx));
225
if (rc != GPG_ERR_NO_ERROR){
226
fprintf(stderr, "bad gpgme_new: %s: %s\n",
227
gpgme_strsource(rc), gpgme_strerror(rc));
228
return false;
229
}
230
231
if (not import_key(pubkey) or not import_key(seckey)){
232
return false;
233
}
234
235
return true;
236
}
237
238
/*
239
* Decrypt OpenPGP data.
240
* Returns -1 on error
241
*/
242
static ssize_t pgp_packet_decrypt (const mandos_context *mc,
243
const char *cryptotext,
244
size_t crypto_size,
245
char **plaintext){
246
gpgme_data_t dh_crypto, dh_plain;
247
gpgme_error_t rc;
248
ssize_t ret;
249
size_t plaintext_capacity = 0;
250
ssize_t plaintext_length = 0;
251
252
if (debug){
253
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
254
}
255
256
/* Create new GPGME data buffer from memory cryptotext */
257
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
258
0);
259
if (rc != GPG_ERR_NO_ERROR){
260
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
261
gpgme_strsource(rc), gpgme_strerror(rc));
262
return -1;
263
}
264
265
/* Create new empty GPGME data buffer for the plaintext */
266
rc = gpgme_data_new(&dh_plain);
267
if (rc != GPG_ERR_NO_ERROR){
268
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
269
gpgme_strsource(rc), gpgme_strerror(rc));
270
gpgme_data_release(dh_crypto);
271
return -1;
272
}
273
274
/* Decrypt data from the cryptotext data buffer to the plaintext
275
data buffer */
276
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
277
if (rc != GPG_ERR_NO_ERROR){
278
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
279
gpgme_strsource(rc), gpgme_strerror(rc));
280
plaintext_length = -1;
281
if (debug){
282
gpgme_decrypt_result_t result;
283
result = gpgme_op_decrypt_result(mc->ctx);
284
if (result == NULL){
285
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
286
} else {
287
fprintf(stderr, "Unsupported algorithm: %s\n",
288
result->unsupported_algorithm);
289
fprintf(stderr, "Wrong key usage: %u\n",
290
result->wrong_key_usage);
291
if(result->file_name != NULL){
292
fprintf(stderr, "File name: %s\n", result->file_name);
293
}
294
gpgme_recipient_t recipient;
295
recipient = result->recipients;
296
if(recipient){
297
while(recipient != NULL){
298
fprintf(stderr, "Public key algorithm: %s\n",
299
gpgme_pubkey_algo_name(recipient->pubkey_algo));
300
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
301
fprintf(stderr, "Secret key available: %s\n",
302
recipient->status == GPG_ERR_NO_SECKEY
303
? "No" : "Yes");
304
recipient = recipient->next;
305
}
306
}
307
}
308
}
309
goto decrypt_end;
310
}
311
312
if(debug){
313
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
314
}
315
316
/* Seek back to the beginning of the GPGME plaintext data buffer */
317
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
318
perror("gpgme_data_seek");
319
plaintext_length = -1;
320
goto decrypt_end;
321
}
322
323
*plaintext = NULL;
324
while(true){
325
plaintext_capacity = adjustbuffer(plaintext,
326
(size_t)plaintext_length,
327
plaintext_capacity);
328
if (plaintext_capacity == 0){
329
perror("adjustbuffer");
330
plaintext_length = -1;
331
goto decrypt_end;
332
}
333
334
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
335
BUFFER_SIZE);
336
/* Print the data, if any */
337
if (ret == 0){
338
/* EOF */
339
break;
340
}
341
if(ret < 0){
342
perror("gpgme_data_read");
343
plaintext_length = -1;
344
goto decrypt_end;
345
}
346
plaintext_length += ret;
347
}
348
349
if(debug){
350
fprintf(stderr, "Decrypted password is: ");
351
for(ssize_t i = 0; i < plaintext_length; i++){
352
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
353
}
354
fprintf(stderr, "\n");
355
}
356
357
decrypt_end:
358
359
/* Delete the GPGME cryptotext data buffer */
360
gpgme_data_release(dh_crypto);
361
362
/* Delete the GPGME plaintext data buffer */
363
gpgme_data_release(dh_plain);
364
return plaintext_length;
365
}
366
367
static const char * safer_gnutls_strerror (int value) {
368
const char *ret = gnutls_strerror (value); /* Spurious warning */
369
if (ret == NULL)
370
ret = "(unknown)";
371
return ret;
372
}
373
374
/* GnuTLS log function callback */
375
static void debuggnutls(__attribute__((unused)) int level,
376
const char* string){
377
fprintf(stderr, "GnuTLS: %s", string);
378
}
379
380
static int init_gnutls_global(mandos_context *mc,
381
const char *pubkeyfilename,
382
const char *seckeyfilename){
383
int ret;
384
385
if(debug){
386
fprintf(stderr, "Initializing GnuTLS\n");
387
}
388
389
ret = gnutls_global_init();
390
if (ret != GNUTLS_E_SUCCESS) {
391
fprintf (stderr, "GnuTLS global_init: %s\n",
392
safer_gnutls_strerror(ret));
393
return -1;
394
}
395
396
if (debug){
397
/* "Use a log level over 10 to enable all debugging options."
398
* - GnuTLS manual
399
*/
400
gnutls_global_set_log_level(11);
401
gnutls_global_set_log_function(debuggnutls);
402
}
403
404
/* OpenPGP credentials */
405
gnutls_certificate_allocate_credentials(&mc->cred);
406
if (ret != GNUTLS_E_SUCCESS){
407
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
408
warning */
409
safer_gnutls_strerror(ret));
410
gnutls_global_deinit ();
411
return -1;
412
}
413
414
if(debug){
415
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
416
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
417
seckeyfilename);
418
}
419
420
ret = gnutls_certificate_set_openpgp_key_file
421
(mc->cred, pubkeyfilename, seckeyfilename,
422
GNUTLS_OPENPGP_FMT_BASE64);
423
if (ret != GNUTLS_E_SUCCESS) {
424
fprintf(stderr,
425
"Error[%d] while reading the OpenPGP key pair ('%s',"
426
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
427
fprintf(stderr, "The GnuTLS error is: %s\n",
428
safer_gnutls_strerror(ret));
429
goto globalfail;
430
}
431
432
/* GnuTLS server initialization */
433
ret = gnutls_dh_params_init(&mc->dh_params);
434
if (ret != GNUTLS_E_SUCCESS) {
435
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
436
" %s\n", safer_gnutls_strerror(ret));
437
goto globalfail;
438
}
439
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
440
if (ret != GNUTLS_E_SUCCESS) {
441
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
442
safer_gnutls_strerror(ret));
443
goto globalfail;
444
}
445
446
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
447
448
return 0;
449
450
globalfail:
451
452
gnutls_certificate_free_credentials(mc->cred);
453
gnutls_global_deinit();
454
gnutls_dh_params_deinit(mc->dh_params);
455
return -1;
456
}
457
458
static int init_gnutls_session(mandos_context *mc,
459
gnutls_session_t *session){
460
int ret;
461
/* GnuTLS session creation */
462
ret = gnutls_init(session, GNUTLS_SERVER);
463
if (ret != GNUTLS_E_SUCCESS){
464
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
465
safer_gnutls_strerror(ret));
466
}
467
468
{
469
const char *err;
470
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
471
if (ret != GNUTLS_E_SUCCESS) {
472
fprintf(stderr, "Syntax error at: %s\n", err);
473
fprintf(stderr, "GnuTLS error: %s\n",
474
safer_gnutls_strerror(ret));
475
gnutls_deinit (*session);
476
return -1;
477
}
478
}
479
480
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
481
mc->cred);
482
if (ret != GNUTLS_E_SUCCESS) {
483
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
484
safer_gnutls_strerror(ret));
485
gnutls_deinit (*session);
486
return -1;
487
}
488
489
/* ignore client certificate if any. */
490
gnutls_certificate_server_set_request (*session,
491
GNUTLS_CERT_IGNORE);
492
493
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
494
495
return 0;
496
}
497
498
/* Avahi log function callback */
499
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
500
__attribute__((unused)) const char *txt){}
501
502
/* Called when a Mandos server is found */
503
static int start_mandos_communication(const char *ip, uint16_t port,
504
AvahiIfIndex if_index,
505
mandos_context *mc){
506
int ret, tcp_sd;
507
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
508
char *buffer = NULL;
509
char *decrypted_buffer;
510
size_t buffer_length = 0;
511
size_t buffer_capacity = 0;
512
ssize_t decrypted_buffer_size;
513
size_t written;
514
int retval = 0;
515
char interface[IF_NAMESIZE];
516
gnutls_session_t session;
517
518
ret = init_gnutls_session (mc, &session);
519
if (ret != 0){
520
return -1;
521
}
522
523
if(debug){
524
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
525
"\n", ip, port);
526
}
527
528
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
529
if(tcp_sd < 0) {
530
perror("socket");
531
return -1;
532
}
533
534
if(debug){
535
if(if_indextoname((unsigned int)if_index, interface) == NULL){
536
perror("if_indextoname");
537
return -1;
538
}
539
fprintf(stderr, "Binding to interface %s\n", interface);
540
}
541
542
memset(&to, 0, sizeof(to));
543
to.in6.sin6_family = AF_INET6;
544
/* It would be nice to have a way to detect if we were passed an
545
IPv4 address here. Now we assume an IPv6 address. */
546
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
547
if (ret < 0 ){
548
perror("inet_pton");
549
return -1;
550
}
551
if(ret == 0){
552
fprintf(stderr, "Bad address: %s\n", ip);
553
return -1;
554
}
555
to.in6.sin6_port = htons(port); /* Spurious warning */
556
557
to.in6.sin6_scope_id = (uint32_t)if_index;
558
559
if(debug){
560
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
561
port);
562
char addrstr[INET6_ADDRSTRLEN] = "";
563
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
564
sizeof(addrstr)) == NULL){
565
perror("inet_ntop");
566
} else {
567
if(strcmp(addrstr, ip) != 0){
568
fprintf(stderr, "Canonical address form: %s\n", addrstr);
569
}
570
}
571
}
572
573
ret = connect(tcp_sd, &to.in, sizeof(to));
574
if (ret < 0){
575
perror("connect");
576
return -1;
577
}
578
579
const char *out = mandos_protocol_version;
580
written = 0;
581
while (true){
582
size_t out_size = strlen(out);
583
ret = TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
584
out_size - written));
585
if (ret == -1){
586
perror("write");
587
retval = -1;
588
goto mandos_end;
589
}
590
written += (size_t)ret;
591
if(written < out_size){
592
continue;
593
} else {
594
if (out == mandos_protocol_version){
595
written = 0;
596
out = "\r\n";
597
} else {
598
break;
599
}
600
}
601
}
602
603
if(debug){
604
fprintf(stderr, "Establishing TLS session with %s\n", ip);
605
}
606
607
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
608
609
do{
610
ret = gnutls_handshake (session);
611
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
612
613
if (ret != GNUTLS_E_SUCCESS){
614
if(debug){
615
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
616
gnutls_perror (ret);
617
}
618
retval = -1;
619
goto mandos_end;
620
}
621
622
/* Read OpenPGP packet that contains the wanted password */
623
624
if(debug){
625
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
626
ip);
627
}
628
629
while(true){
630
buffer_capacity = adjustbuffer(&buffer, buffer_length,
631
buffer_capacity);
632
if (buffer_capacity == 0){
633
perror("adjustbuffer");
634
retval = -1;
635
goto mandos_end;
636
}
637
638
ret = gnutls_record_recv(session, buffer+buffer_length,
639
BUFFER_SIZE);
640
if (ret == 0){
641
break;
642
}
643
if (ret < 0){
644
switch(ret){
645
case GNUTLS_E_INTERRUPTED:
646
case GNUTLS_E_AGAIN:
647
break;
648
case GNUTLS_E_REHANDSHAKE:
649
do{
650
ret = gnutls_handshake (session);
651
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
652
if (ret < 0){
653
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
654
gnutls_perror (ret);
655
retval = -1;
656
goto mandos_end;
657
}
658
break;
659
default:
660
fprintf(stderr, "Unknown error while reading data from"
661
" encrypted session with Mandos server\n");
662
retval = -1;
663
gnutls_bye (session, GNUTLS_SHUT_RDWR);
664
goto mandos_end;
665
}
666
} else {
667
buffer_length += (size_t) ret;
668
}
669
}
670
671
if(debug){
672
fprintf(stderr, "Closing TLS session\n");
673
}
674
675
gnutls_bye (session, GNUTLS_SHUT_RDWR);
676
677
if (buffer_length > 0){
678
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
679
buffer_length,
680
&decrypted_buffer);
681
if (decrypted_buffer_size >= 0){
682
written = 0;
683
while(written < (size_t) decrypted_buffer_size){
684
ret = (int)fwrite (decrypted_buffer + written, 1,
685
(size_t)decrypted_buffer_size - written,
686
stdout);
687
if(ret == 0 and ferror(stdout)){
688
if(debug){
689
fprintf(stderr, "Error writing encrypted data: %s\n",
690
strerror(errno));
691
}
692
retval = -1;
693
break;
694
}
695
written += (size_t)ret;
696
}
697
free(decrypted_buffer);
698
} else {
699
retval = -1;
700
}
701
} else {
702
retval = -1;
703
}
704
705
/* Shutdown procedure */
706
707
mandos_end:
708
free(buffer);
709
ret = TEMP_FAILURE_RETRY(close(tcp_sd));
710
if(ret == -1){
711
perror("close");
712
}
713
gnutls_deinit (session);
714
return retval;
715
}
716
717
static void resolve_callback(AvahiSServiceResolver *r,
718
AvahiIfIndex interface,
719
AVAHI_GCC_UNUSED AvahiProtocol protocol,
720
AvahiResolverEvent event,
721
const char *name,
722
const char *type,
723
const char *domain,
724
const char *host_name,
725
const AvahiAddress *address,
726
uint16_t port,
727
AVAHI_GCC_UNUSED AvahiStringList *txt,
728
AVAHI_GCC_UNUSED AvahiLookupResultFlags
729
flags,
730
void* userdata) {
731
mandos_context *mc = userdata;
732
assert(r);
733
734
/* Called whenever a service has been resolved successfully or
735
timed out */
736
737
switch (event) {
738
default:
739
case AVAHI_RESOLVER_FAILURE:
740
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
741
" of type '%s' in domain '%s': %s\n", name, type, domain,
742
avahi_strerror(avahi_server_errno(mc->server)));
743
break;
744
745
case AVAHI_RESOLVER_FOUND:
746
{
747
char ip[AVAHI_ADDRESS_STR_MAX];
748
avahi_address_snprint(ip, sizeof(ip), address);
749
if(debug){
750
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
751
PRIu16 ") on port %d\n", name, host_name, ip,
752
interface, port);
753
}
754
int ret = start_mandos_communication(ip, port, interface, mc);
755
if (ret == 0){
756
avahi_simple_poll_quit(mc->simple_poll);
757
}
758
}
759
}
760
avahi_s_service_resolver_free(r);
761
}
762
763
static void browse_callback( AvahiSServiceBrowser *b,
764
AvahiIfIndex interface,
765
AvahiProtocol protocol,
766
AvahiBrowserEvent event,
767
const char *name,
768
const char *type,
769
const char *domain,
770
AVAHI_GCC_UNUSED AvahiLookupResultFlags
771
flags,
772
void* userdata) {
773
mandos_context *mc = userdata;
774
assert(b);
775
776
/* Called whenever a new services becomes available on the LAN or
777
is removed from the LAN */
778
779
switch (event) {
780
default:
781
case AVAHI_BROWSER_FAILURE:
782
783
fprintf(stderr, "(Avahi browser) %s\n",
784
avahi_strerror(avahi_server_errno(mc->server)));
785
avahi_simple_poll_quit(mc->simple_poll);
786
return;
787
788
case AVAHI_BROWSER_NEW:
789
/* We ignore the returned Avahi resolver object. In the callback
790
function we free it. If the Avahi server is terminated before
791
the callback function is called the Avahi server will free the
792
resolver for us. */
793
794
if (!(avahi_s_service_resolver_new(mc->server, interface,
795
protocol, name, type, domain,
796
AVAHI_PROTO_INET6, 0,
797
resolve_callback, mc)))
798
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
799
name, avahi_strerror(avahi_server_errno(mc->server)));
800
break;
801
802
case AVAHI_BROWSER_REMOVE:
803
break;
804
805
case AVAHI_BROWSER_ALL_FOR_NOW:
806
case AVAHI_BROWSER_CACHE_EXHAUSTED:
807
if(debug){
808
fprintf(stderr, "No Mandos server found, still searching...\n");
809
}
810
break;
811
}
812
}
813
814
int main(int argc, char *argv[]){
815
AvahiSServiceBrowser *sb = NULL;
816
int error;
817
int ret;
818
int exitcode = EXIT_SUCCESS;
819
const char *interface = "eth0";
820
struct ifreq network;
821
int sd;
822
uid_t uid;
823
gid_t gid;
824
char *connect_to = NULL;
825
char tempdir[] = "/tmp/mandosXXXXXX";
826
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
827
const char *seckey = PATHDIR "/" SECKEY;
828
const char *pubkey = PATHDIR "/" PUBKEY;
829
830
mandos_context mc = { .simple_poll = NULL, .server = NULL,
831
.dh_bits = 1024, .priority = "SECURE256"
832
":!CTYPE-X.509:+CTYPE-OPENPGP" };
833
bool gnutls_initalized = false;
834
bool gpgme_initalized = false;
835
836
{
837
struct argp_option options[] = {
838
{ .name = "debug", .key = 128,
839
.doc = "Debug mode", .group = 3 },
840
{ .name = "connect", .key = 'c',
841
.arg = "ADDRESS:PORT",
842
.doc = "Connect directly to a specific Mandos server",
843
.group = 1 },
844
{ .name = "interface", .key = 'i',
845
.arg = "NAME",
846
.doc = "Interface that will be used to search for Mandos"
847
" servers",
848
.group = 1 },
849
{ .name = "seckey", .key = 's',
850
.arg = "FILE",
851
.doc = "OpenPGP secret key file base name",
852
.group = 1 },
853
{ .name = "pubkey", .key = 'p',
854
.arg = "FILE",
855
.doc = "OpenPGP public key file base name",
856
.group = 2 },
857
{ .name = "dh-bits", .key = 129,
858
.arg = "BITS",
859
.doc = "Bit length of the prime number used in the"
860
" Diffie-Hellman key exchange",
861
.group = 2 },
862
{ .name = "priority", .key = 130,
863
.arg = "STRING",
864
.doc = "GnuTLS priority string for the TLS handshake",
865
.group = 1 },
866
{ .name = NULL }
867
};
868
869
error_t parse_opt (int key, char *arg,
870
struct argp_state *state) {
871
/* Get the INPUT argument from `argp_parse', which we know is
872
a pointer to our plugin list pointer. */
873
switch (key) {
874
case 128: /* --debug */
875
debug = true;
876
break;
877
case 'c': /* --connect */
878
connect_to = arg;
879
break;
880
case 'i': /* --interface */
881
interface = arg;
882
break;
883
case 's': /* --seckey */
884
seckey = arg;
885
break;
886
case 'p': /* --pubkey */
887
pubkey = arg;
888
break;
889
case 129: /* --dh-bits */
890
errno = 0;
891
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
892
if (errno){
893
perror("strtol");
894
exit(EXIT_FAILURE);
895
}
896
break;
897
case 130: /* --priority */
898
mc.priority = arg;
899
break;
900
case ARGP_KEY_ARG:
901
argp_usage (state);
902
case ARGP_KEY_END:
903
break;
904
default:
905
return ARGP_ERR_UNKNOWN;
906
}
907
return 0;
908
}
909
910
struct argp argp = { .options = options, .parser = parse_opt,
911
.args_doc = "",
912
.doc = "Mandos client -- Get and decrypt"
913
" passwords from a Mandos server" };
914
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
915
if (ret == ARGP_ERR_UNKNOWN){
916
fprintf(stderr, "Unknown error while parsing arguments\n");
917
exitcode = EXIT_FAILURE;
918
goto end;
919
}
920
}
921
922
/* If the interface is down, bring it up */
923
{
924
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
925
if(sd < 0) {
926
perror("socket");
927
exitcode = EXIT_FAILURE;
928
goto end;
929
}
930
strcpy(network.ifr_name, interface);
931
ret = ioctl(sd, SIOCGIFFLAGS, &network);
932
if(ret == -1){
933
perror("ioctl SIOCGIFFLAGS");
934
exitcode = EXIT_FAILURE;
935
goto end;
936
}
937
if((network.ifr_flags & IFF_UP) == 0){
938
network.ifr_flags |= IFF_UP;
939
ret = ioctl(sd, SIOCSIFFLAGS, &network);
940
if(ret == -1){
941
perror("ioctl SIOCSIFFLAGS");
942
exitcode = EXIT_FAILURE;
943
goto end;
944
}
945
}
946
ret = TEMP_FAILURE_RETRY(close(sd));
947
if(ret == -1){
948
perror("close");
949
}
950
}
951
952
uid = getuid();
953
gid = getgid();
954
955
ret = setuid(uid);
956
if (ret == -1){
957
perror("setuid");
958
}
959
960
setgid(gid);
961
if (ret == -1){
962
perror("setgid");
963
}
964
965
ret = init_gnutls_global(&mc, pubkey, seckey);
966
if (ret == -1){
967
fprintf(stderr, "init_gnutls_global failed\n");
968
exitcode = EXIT_FAILURE;
969
goto end;
970
} else {
971
gnutls_initalized = true;
972
}
973
974
if(mkdtemp(tempdir) == NULL){
975
perror("mkdtemp");
976
tempdir[0] = '\0';
977
goto end;
978
}
979
980
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
981
fprintf(stderr, "gpgme_initalized failed\n");
982
exitcode = EXIT_FAILURE;
983
goto end;
984
} else {
985
gpgme_initalized = true;
986
}
987
988
if_index = (AvahiIfIndex) if_nametoindex(interface);
989
if(if_index == 0){
990
fprintf(stderr, "No such interface: \"%s\"\n", interface);
991
exit(EXIT_FAILURE);
992
}
993
994
if(connect_to != NULL){
995
/* Connect directly, do not use Zeroconf */
996
/* (Mainly meant for debugging) */
997
char *address = strrchr(connect_to, ':');
998
if(address == NULL){
999
fprintf(stderr, "No colon in address\n");
1000
exitcode = EXIT_FAILURE;
1001
goto end;
1002
}
1003
errno = 0;
1004
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
1005
if(errno){
1006
perror("Bad port number");
1007
exitcode = EXIT_FAILURE;
1008
goto end;
1009
}
1010
*address = '\0';
1011
address = connect_to;
1012
ret = start_mandos_communication(address, port, if_index, &mc);
1013
if(ret < 0){
1014
exitcode = EXIT_FAILURE;
1015
} else {
1016
exitcode = EXIT_SUCCESS;
1017
}
1018
goto end;
1019
}
1020
1021
if (not debug){
1022
avahi_set_log_function(empty_log);
1023
}
1024
1025
/* Initialize the pseudo-RNG for Avahi */
1026
srand((unsigned int) time(NULL));
1027
1028
/* Allocate main Avahi loop object */
1029
mc.simple_poll = avahi_simple_poll_new();
1030
if (mc.simple_poll == NULL) {
1031
fprintf(stderr, "Avahi: Failed to create simple poll"
1032
" object.\n");
1033
exitcode = EXIT_FAILURE;
1034
goto end;
1035
}
1036
1037
{
1038
AvahiServerConfig config;
1039
/* Do not publish any local Zeroconf records */
1040
avahi_server_config_init(&config);
1041
config.publish_hinfo = 0;
1042
config.publish_addresses = 0;
1043
config.publish_workstation = 0;
1044
config.publish_domain = 0;
1045
1046
/* Allocate a new server */
1047
mc.server = avahi_server_new(avahi_simple_poll_get
1048
(mc.simple_poll), &config, NULL,
1049
NULL, &error);
1050
1051
/* Free the Avahi configuration data */
1052
avahi_server_config_free(&config);
1053
}
1054
1055
/* Check if creating the Avahi server object succeeded */
1056
if (mc.server == NULL) {
1057
fprintf(stderr, "Failed to create Avahi server: %s\n",
1058
avahi_strerror(error));
1059
exitcode = EXIT_FAILURE;
1060
goto end;
1061
}
1062
1063
/* Create the Avahi service browser */
1064
sb = avahi_s_service_browser_new(mc.server, if_index,
1065
AVAHI_PROTO_INET6,
1066
"_mandos._tcp", NULL, 0,
1067
browse_callback, &mc);
1068
if (sb == NULL) {
1069
fprintf(stderr, "Failed to create service browser: %s\n",
1070
avahi_strerror(avahi_server_errno(mc.server)));
1071
exitcode = EXIT_FAILURE;
1072
goto end;
1073
}
1074
1075
/* Run the main loop */
1076
1077
if (debug){
1078
fprintf(stderr, "Starting Avahi loop search\n");
1079
}
1080
1081
avahi_simple_poll_loop(mc.simple_poll);
1082
1083
end:
1084
1085
if (debug){
1086
fprintf(stderr, "%s exiting\n", argv[0]);
1087
}
1088
1089
/* Cleanup things */
1090
if (sb != NULL)
1091
avahi_s_service_browser_free(sb);
1092
1093
if (mc.server != NULL)
1094
avahi_server_free(mc.server);
1095
1096
if (mc.simple_poll != NULL)
1097
avahi_simple_poll_free(mc.simple_poll);
1098
1099
if (gnutls_initalized){
1100
gnutls_certificate_free_credentials(mc.cred);
1101
gnutls_global_deinit ();
1102
gnutls_dh_params_deinit(mc.dh_params);
1103
}
1104
1105
if(gpgme_initalized){
1106
gpgme_release(mc.ctx);
1107
}
1108
1109
/* Removes the temp directory used by GPGME */
1110
if(tempdir[0] != '\0'){
1111
DIR *d;
1112
struct dirent *direntry;
1113
d = opendir(tempdir);
1114
if(d == NULL){
1115
perror("opendir");
1116
} else {
1117
while(true){
1118
direntry = readdir(d);
1119
if(direntry == NULL){
1120
break;
1121
}
1122
if (direntry->d_type == DT_REG){
1123
char *fullname = NULL;
1124
ret = asprintf(&fullname, "%s/%s", tempdir,
1125
direntry->d_name);
1126
if(ret < 0){
1127
perror("asprintf");
1128
continue;
1129
}
1130
ret = unlink(fullname);
1131
if(ret == -1){
1132
fprintf(stderr, "unlink(\"%s\"): %s",
1133
fullname, strerror(errno));
1134
}
1135
free(fullname);
1136
}
1137
}
1138
closedir(d);
1139
}
1140
ret = rmdir(tempdir);
1141
if(ret == -1){
1142
perror("rmdir");
1143
}
1144
}
1145
1146
return exitcode;
1147
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0