4
* This file demonstrates how to use Avahi's core API, this is
5
* the embeddable mDNS stack for embedded applications.
1
/* -*- coding: utf-8 -*- */
3
* Mandos client - get and decrypt data from a Mandos server
7
* End user applications should *not* use this API and should use
8
* the D-Bus or C APIs, please see
9
* client-browse-services.c and glib-integration.c
11
* I repeat, you probably do *not* want to use this example.
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".
11
* Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
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.
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.
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/>.
28
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
29
* <https://www.fukt.bsnet.se/~teddy/>.
15
This file is part of avahi.
17
avahi is free software; you can redistribute it and/or modify it
18
under the terms of the GNU Lesser General Public License as
19
published by the Free Software Foundation; either version 2.1 of the
20
License, or (at your option) any later version.
22
avahi is distributed in the hope that it will be useful, but WITHOUT
23
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
25
Public License for more details.
27
You should have received a copy of the GNU Lesser General Public
28
License along with avahi; if not, write to the Free Software
29
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
32
#define _FORTIFY_SOURCE 2
33
34
#define _LARGEFILE_SOURCE
34
35
#define _FILE_OFFSET_BITS 64
47
48
#include <avahi-common/error.h>
49
50
//mandos client part
50
#include <sys/types.h> /* socket(), setsockopt(), inet_pton() */
51
#include <sys/socket.h> /* socket(), setsockopt(), struct sockaddr_in6, struct in6_addr, inet_pton() */
52
#include <gnutls/gnutls.h> /* ALL GNUTLS STUFF */
53
#include <gnutls/openpgp.h> /* gnutls with openpgp stuff */
51
#include <sys/types.h> /* socket(), setsockopt(),
53
#include <sys/socket.h> /* socket(), setsockopt(),
55
struct in6_addr, inet_pton() */
56
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
57
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
55
59
#include <unistd.h> /* close() */
56
60
#include <netinet/in.h>
79
87
} encrypted_session;
82
ssize_t gpg_packet_decrypt (char *packet, size_t packet_size, char **new_packet, char *homedir){
90
ssize_t pgp_packet_decrypt (char *packet, size_t packet_size,
91
char **new_packet, const char *homedir){
83
92
gpgme_data_t dh_crypto, dh_plain;
87
size_t new_packet_capacity = 0;
88
size_t new_packet_length = 0;
96
ssize_t new_packet_capacity = 0;
97
ssize_t new_packet_length = 0;
89
98
gpgme_engine_info_t engine_info;
101
fprintf(stderr, "Trying to decrypt OpenPGP packet\n");
92
105
gpgme_check_version(NULL);
93
106
gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
139
/* Decrypt data from the FILE pointer to the plaintext data buffer */
152
/* Decrypt data from the FILE pointer to the plaintext data
140
154
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
141
155
if (rc != GPG_ERR_NO_ERROR){
142
156
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
143
157
gpgme_strsource(rc), gpgme_strerror(rc));
162
fprintf(stderr, "Decryption of OpenPGP packet succeeded\n");
166
gpgme_decrypt_result_t result;
167
result = gpgme_op_decrypt_result(ctx);
169
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
171
fprintf(stderr, "Unsupported algorithm: %s\n",
172
result->unsupported_algorithm);
173
fprintf(stderr, "Wrong key usage: %d\n",
174
result->wrong_key_usage);
175
if(result->file_name != NULL){
176
fprintf(stderr, "File name: %s\n", result->file_name);
178
gpgme_recipient_t recipient;
179
recipient = result->recipients;
181
while(recipient != NULL){
182
fprintf(stderr, "Public key algorithm: %s\n",
183
gpgme_pubkey_algo_name(recipient->pubkey_algo));
184
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
185
fprintf(stderr, "Secret key available: %s\n",
186
recipient->status == GPG_ERR_NO_SECKEY
188
recipient = recipient->next;
147
/* gpgme_decrypt_result_t result; */
148
/* result = gpgme_op_decrypt_result(ctx); */
149
/* fprintf(stderr, "Unsupported algorithm: %s\n", result->unsupported_algorithm); */
150
/* fprintf(stderr, "Wrong key usage: %d\n", result->wrong_key_usage); */
151
/* if(result->file_name != NULL){ */
152
/* fprintf(stderr, "File name: %s\n", result->file_name); */
154
/* gpgme_recipient_t recipient; */
155
/* recipient = result->recipients; */
157
/* while(recipient != NULL){ */
158
/* fprintf(stderr, "Public key algorithm: %s\n", */
159
/* gpgme_pubkey_algo_name(recipient->pubkey_algo)); */
160
/* fprintf(stderr, "Key ID: %s\n", recipient->keyid); */
161
/* fprintf(stderr, "Secret key available: %s\n", */
162
/* recipient->status == GPG_ERR_NO_SECKEY ? "No" : "Yes"); */
163
/* recipient = recipient->next; */
167
194
/* Delete the GPGME FILE pointer cryptotext data buffer */
168
195
gpgme_data_release(dh_crypto);
194
223
new_packet_length += ret;
197
/* Delete the GPGME plaintext data buffer */
226
/* FIXME: check characters before printing to screen so to not print
227
terminal control characters */
229
/* fprintf(stderr, "decrypted password is: "); */
230
/* fwrite(*new_packet, 1, new_packet_length, stderr); */
231
/* fprintf(stderr, "\n"); */
234
/* Delete the GPGME plaintext data buffer */
198
235
gpgme_data_release(dh_plain);
199
236
return new_packet_length;
256
fprintf(stderr, "Initializing GnuTLS\n");
217
259
if ((ret = gnutls_global_init ())
218
260
!= GNUTLS_E_SUCCESS) {
219
261
fprintf (stderr, "global_init: %s\n", safer_gnutls_strerror(ret));
223
/* Uncomment to enable full debuggin on the gnutls library */
224
/* gnutls_global_set_log_level(11); */
225
/* gnutls_global_set_log_function(debuggnutls); */
266
gnutls_global_set_log_level(11);
267
gnutls_global_set_log_function(debuggnutls);
228
270
/* openpgp credentials */
229
271
if ((ret = gnutls_certificate_allocate_credentials (&es->cred))
230
272
!= GNUTLS_E_SUCCESS) {
231
fprintf (stderr, "memory error: %s\n", safer_gnutls_strerror(ret));
273
fprintf (stderr, "memory error: %s\n",
274
safer_gnutls_strerror(ret));
279
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
280
" and keyfile %s as GnuTLS credentials\n", CERTFILE,
235
284
ret = gnutls_certificate_set_openpgp_key_file
236
285
(es->cred, CERTFILE, KEYFILE, GNUTLS_OPENPGP_FMT_BASE64);
237
286
if (ret != GNUTLS_E_SUCCESS) {
239
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s', '%s')\n",
288
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s',"
240
290
ret, CERTFILE, KEYFILE);
241
291
fprintf(stdout, "The Error is: %s\n",
242
292
safer_gnutls_strerror(ret));
246
//Gnutls server initialization
296
//GnuTLS server initialization
247
297
if ((ret = gnutls_dh_params_init (&es->dh_params))
248
298
!= GNUTLS_E_SUCCESS) {
249
299
fprintf (stderr, "Error in dh parameter initialization: %s\n",
250
300
safer_gnutls_strerror(ret));
254
304
if ((ret = gnutls_dh_params_generate2 (es->dh_params, DH_BITS))
255
305
!= GNUTLS_E_SUCCESS) {
256
306
fprintf (stderr, "Error in prime generation: %s\n",
257
307
safer_gnutls_strerror(ret));
261
311
gnutls_certificate_set_dh_params (es->cred, es->dh_params);
263
// Gnutls session creation
313
// GnuTLS session creation
264
314
if ((ret = gnutls_init (&es->session, GNUTLS_SERVER))
265
315
!= GNUTLS_E_SUCCESS){
266
fprintf(stderr, "Error in gnutls session initialization: %s\n",
316
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
267
317
safer_gnutls_strerror(ret));
270
320
if ((ret = gnutls_priority_set_direct (es->session, "NORMAL", &err))
271
321
!= GNUTLS_E_SUCCESS) {
272
322
fprintf(stderr, "Syntax error at: %s\n", err);
273
fprintf(stderr, "Gnutls error: %s\n",
323
fprintf(stderr, "GnuTLS error: %s\n",
274
324
safer_gnutls_strerror(ret));
278
328
if ((ret = gnutls_credentials_set
279
329
(es->session, GNUTLS_CRD_CERTIFICATE, es->cred))
280
330
!= GNUTLS_E_SUCCESS) {
282
332
safer_gnutls_strerror(ret));
286
336
/* ignore client certificate if any. */
287
gnutls_certificate_server_set_request (es->session, GNUTLS_CERT_IGNORE);
337
gnutls_certificate_server_set_request (es->session,
289
340
gnutls_dh_set_prime_bits (es->session, DH_BITS);
294
void empty_log(AvahiLogLevel level, const char *txt){}
345
void empty_log(__attribute__((unused)) AvahiLogLevel level,
346
__attribute__((unused)) const char *txt){}
296
int start_mandos_communcation(char *ip, uint16_t port){
348
int start_mandos_communication(char *ip, uint16_t port,
349
unsigned int if_index){
298
351
struct sockaddr_in6 to;
299
struct in6_addr ip_addr;
300
352
encrypted_session es;
301
353
char *buffer = NULL;
302
354
char *decrypted_buffer;
315
ret = setsockopt(tcp_sd, SOL_SOCKET, SO_BINDTODEVICE, "eth0", 5);
371
if(if_indextoname(if_index, interface) == NULL){
373
perror("if_indextoname");
379
fprintf(stderr, "Binding to interface %s\n", interface);
382
ret = setsockopt(tcp_sd, SOL_SOCKET, SO_BINDTODEVICE, interface, 5);
317
384
perror("setsockopt bindtodevice");
321
388
memset(&to,0,sizeof(to));
322
389
to.sin6_family = AF_INET6;
323
ret = inet_pton(AF_INET6, ip, &ip_addr);
390
ret = inet_pton(AF_INET6, ip, &to.sin6_addr);
325
392
perror("inet_pton");
329
396
fprintf(stderr, "Bad address: %s\n", ip);
399
/* Spurious warnings for the next line, see for instance
400
<http://bugs.debian.org/488884> */
332
401
to.sin6_port = htons(port);
333
to.sin6_scope_id = if_nametoindex("eth0");
403
to.sin6_scope_id = (uint32_t)if_index;
406
fprintf(stderr, "Connection to: %s\n", ip);
335
409
ret = connect(tcp_sd, (struct sockaddr *) &to, sizeof(to));
390
fprintf(stderr, "Unknown error while reading data from encrypted session with mandos server\n");
474
fprintf(stderr, "Unknown error while reading data from"
475
" encrypted session with mandos server\n");
392
477
gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
396
buffer_length += ret;
481
buffer_length += (size_t) ret;
400
485
if (buffer_length > 0){
401
if ((decrypted_buffer_size = gpg_packet_decrypt(buffer, buffer_length, &decrypted_buffer, CERT_ROOT)) == 0){
486
decrypted_buffer_size = pgp_packet_decrypt(buffer,
490
if (decrypted_buffer_size >= 0){
491
while(decrypted_buffer_size > 0){
492
ret = fwrite (decrypted_buffer, 1, (size_t)decrypted_buffer_size,
494
if(ret == 0 and ferror(stdout)){
496
fprintf(stderr, "Error writing encrypted data: %s\n",
502
decrypted_buffer += ret;
503
decrypted_buffer_size -= ret;
505
free(decrypted_buffer);
404
fwrite (decrypted_buffer, 1, decrypted_buffer_size, stdout);
405
free(decrypted_buffer);
514
fprintf(stderr, "Closing TLS session\n");
412
518
gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
432
538
const char *host_name,
433
539
const AvahiAddress *address,
435
AvahiStringList *txt,
436
AvahiLookupResultFlags flags,
541
AVAHI_GCC_UNUSED AvahiStringList *txt,
542
AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
437
543
AVAHI_GCC_UNUSED void* userdata) {
441
/* Called whenever a service has been resolved successfully or timed out */
444
case AVAHI_RESOLVER_FAILURE:
445
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of type '%s' in domain '%s': %s\n", name, type, domain, avahi_strerror(avahi_server_errno(server)));
448
case AVAHI_RESOLVER_FOUND: {
449
char ip[AVAHI_ADDRESS_STR_MAX];
450
avahi_address_snprint(ip, sizeof(ip), address);
451
int ret = start_mandos_communcation(ip, port);
547
/* Called whenever a service has been resolved successfully or
552
case AVAHI_RESOLVER_FAILURE:
553
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
554
" type '%s' in domain '%s': %s\n", name, type, domain,
555
avahi_strerror(avahi_server_errno(server)));
558
case AVAHI_RESOLVER_FOUND:
560
char ip[AVAHI_ADDRESS_STR_MAX];
561
avahi_address_snprint(ip, sizeof(ip), address);
563
fprintf(stderr, "Mandos server found on %s (%s) on port %d\n",
564
host_name, ip, port);
566
int ret = start_mandos_communication(ip, port,
459
avahi_s_service_resolver_free(r);
576
avahi_s_service_resolver_free(r);
462
579
static void browse_callback(
473
590
AvahiServer *s = userdata;
476
/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
593
/* Called whenever a new services becomes available on the LAN or
594
is removed from the LAN */
480
case AVAHI_BROWSER_FAILURE:
482
fprintf(stderr, "(Browser) %s\n", avahi_strerror(avahi_server_errno(server)));
483
avahi_simple_poll_quit(simple_poll);
486
case AVAHI_BROWSER_NEW:
487
/* We ignore the returned resolver object. In the callback
488
function we free it. If the server is terminated before
489
the callback function is called the server will free
490
the resolver for us. */
492
if (!(avahi_s_service_resolver_new(s, interface, protocol, name, type, domain, AVAHI_PROTO_INET6, 0, resolve_callback, s)))
493
fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(s)));
497
case AVAHI_BROWSER_REMOVE:
500
case AVAHI_BROWSER_ALL_FOR_NOW:
501
case AVAHI_BROWSER_CACHE_EXHAUSTED:
598
case AVAHI_BROWSER_FAILURE:
600
fprintf(stderr, "(Browser) %s\n",
601
avahi_strerror(avahi_server_errno(server)));
602
avahi_simple_poll_quit(simple_poll);
605
case AVAHI_BROWSER_NEW:
606
/* We ignore the returned resolver object. In the callback
607
function we free it. If the server is terminated before
608
the callback function is called the server will free
609
the resolver for us. */
611
if (!(avahi_s_service_resolver_new(s, interface, protocol, name,
613
AVAHI_PROTO_INET6, 0,
614
resolve_callback, s)))
615
fprintf(stderr, "Failed to resolve service '%s': %s\n", name,
616
avahi_strerror(avahi_server_errno(s)));
619
case AVAHI_BROWSER_REMOVE:
622
case AVAHI_BROWSER_ALL_FOR_NOW:
623
case AVAHI_BROWSER_CACHE_EXHAUSTED:
507
629
AvahiServerConfig config;
508
630
AvahiSServiceBrowser *sb = NULL;
512
avahi_set_log_function(empty_log);
633
int returncode = EXIT_SUCCESS;
634
const char *interface = "eth0";
637
static struct option long_options[] = {
638
{"debug", no_argument, (int *)&debug, 1},
639
{"interface", required_argument, 0, 'i'},
642
int option_index = 0;
643
ret = getopt_long (argc, argv, "i:", long_options,
662
avahi_set_log_function(empty_log);
514
665
/* Initialize the psuedo-RNG */
666
srand((unsigned int) time(NULL));
517
668
/* Allocate main loop object */
518
669
if (!(simple_poll = avahi_simple_poll_new())) {
519
670
fprintf(stderr, "Failed to create simple poll object.\n");
523
675
/* Do not publish any local records */
527
679
config.publish_workstation = 0;
528
680
config.publish_domain = 0;
530
/* /\* Set a unicast DNS server for wide area DNS-SD *\/ */
531
/* avahi_address_parse("193.11.177.11", AVAHI_PROTO_UNSPEC, &config.wide_area_servers[0]); */
532
/* config.n_wide_area_servers = 1; */
533
/* config.enable_wide_area = 1; */
535
682
/* Allocate a new server */
536
server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
683
server = avahi_server_new(avahi_simple_poll_get(simple_poll),
684
&config, NULL, NULL, &error);
538
686
/* Free the configuration data */
539
687
avahi_server_config_free(&config);
541
/* Check wether creating the server object succeeded */
689
/* Check if creating the server object succeeded */
543
fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
691
fprintf(stderr, "Failed to create server: %s\n",
692
avahi_strerror(error));
693
returncode = EXIT_FAILURE;
547
697
/* Create the service browser */
548
if (!(sb = avahi_s_service_browser_new(server, if_nametoindex("eth0"), AVAHI_PROTO_INET6, "_mandos._tcp", NULL, 0, browse_callback, server))) {
549
fprintf(stderr, "Failed to create service browser: %s\n", avahi_strerror(avahi_server_errno(server)));
698
sb = avahi_s_service_browser_new(server,
700
if_nametoindex(interface),
702
"_mandos._tcp", NULL, 0,
703
browse_callback, server);
705
fprintf(stderr, "Failed to create service browser: %s\n",
706
avahi_strerror(avahi_server_errno(server)));
707
returncode = EXIT_FAILURE;
553
711
/* Run the main loop */
714
fprintf(stderr, "Starting avahi loop search\n");
554
717
avahi_simple_poll_loop(simple_poll);
722
fprintf(stderr, "%s exiting\n", argv[0]);
560
725
/* Cleanup things */