2
This file is part of avahi.
4
avahi is free software; you can redistribute it and/or modify it
5
under the terms of the GNU Lesser General Public License as
6
published by the Free Software Foundation; either version 2.1 of the
7
License, or (at your option) any later version.
9
avahi is distributed in the hope that it will be useful, but WITHOUT
10
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12
Public License for more details.
14
You should have received a copy of the GNU Lesser General Public
15
License along with avahi; if not, write to the Free Software
16
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
1
/* -*- coding: utf-8 -*- */
3
* Mandos client - get and decrypt data from a Mandos server
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/>.
32
#define _FORTIFY_SOURCE 2
20
34
#define _LARGEFILE_SOURCE
21
35
#define _FILE_OFFSET_BITS 64
34
48
#include <avahi-common/error.h>
36
50
//mandos client part
37
#include <sys/types.h> /* socket(), setsockopt(), inet_pton() */
38
#include <sys/socket.h> /* socket(), setsockopt(), struct sockaddr_in6, struct in6_addr, inet_pton() */
39
#include <gnutls/gnutls.h> /* ALL GNUTLS STUFF */
40
#include <gnutls/openpgp.h> /* gnutls with openpgp stuff */
51
#include <sys/types.h> /* socket(), inet_pton() */
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
struct in6_addr, inet_pton() */
54
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
55
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
42
57
#include <unistd.h> /* close() */
43
58
#include <netinet/in.h>
71
85
} encrypted_session;
74
ssize_t gpg_packet_decrypt (char *packet, size_t packet_size, char **new_packet, char *homedir){
88
ssize_t pgp_packet_decrypt (char *packet, size_t packet_size,
89
char **new_packet, const char *homedir){
75
90
gpgme_data_t dh_crypto, dh_plain;
79
size_t new_packet_capacity = 0;
80
size_t new_packet_length = 0;
94
ssize_t new_packet_capacity = 0;
95
ssize_t new_packet_length = 0;
81
96
gpgme_engine_info_t engine_info;
84
fprintf(stderr, "Attempting to decrypt password from gpg packet\n");
99
fprintf(stderr, "Trying to decrypt OpenPGP packet\n");
150
166
if (result == NULL){
151
167
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
153
fprintf(stderr, "Unsupported algorithm: %s\n", result->unsupported_algorithm);
154
fprintf(stderr, "Wrong key usage: %d\n", result->wrong_key_usage);
169
fprintf(stderr, "Unsupported algorithm: %s\n",
170
result->unsupported_algorithm);
171
fprintf(stderr, "Wrong key usage: %d\n",
172
result->wrong_key_usage);
155
173
if(result->file_name != NULL){
156
174
fprintf(stderr, "File name: %s\n", result->file_name);
174
193
gpgme_data_release(dh_crypto);
176
195
/* Seek back to the beginning of the GPGME plaintext data buffer */
177
gpgme_data_seek(dh_plain, 0, SEEK_SET);
196
gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET);
181
200
if (new_packet_length + BUFFER_SIZE > new_packet_capacity){
182
*new_packet = realloc(*new_packet, new_packet_capacity + BUFFER_SIZE);
201
*new_packet = realloc(*new_packet,
202
(unsigned int)new_packet_capacity
183
204
if (*new_packet == NULL){
184
205
perror("realloc");
223
void debuggnutls(int level, const char* string){
244
void debuggnutls(__attribute__((unused)) int level,
224
246
fprintf(stderr, "%s", string);
227
249
int initgnutls(encrypted_session *es){
232
fprintf(stderr, "Initializing gnutls\n");
254
fprintf(stderr, "Initializing GnuTLS\n");
236
257
if ((ret = gnutls_global_init ())
237
258
!= GNUTLS_E_SUCCESS) {
244
265
gnutls_global_set_log_function(debuggnutls);
248
268
/* openpgp credentials */
249
269
if ((ret = gnutls_certificate_allocate_credentials (&es->cred))
250
270
!= GNUTLS_E_SUCCESS) {
251
fprintf (stderr, "memory error: %s\n", safer_gnutls_strerror(ret));
271
fprintf (stderr, "memory error: %s\n",
272
safer_gnutls_strerror(ret));
256
fprintf(stderr, "Attempting to use openpgp certificate %s"
257
" and keyfile %s as gnutls credentials\n", CERTFILE, KEYFILE);
277
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
278
" and keyfile %s as GnuTLS credentials\n", CERTFILE,
260
282
ret = gnutls_certificate_set_openpgp_key_file
261
283
(es->cred, CERTFILE, KEYFILE, GNUTLS_OPENPGP_FMT_BASE64);
262
284
if (ret != GNUTLS_E_SUCCESS) {
264
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s', '%s')\n",
286
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s',"
265
288
ret, CERTFILE, KEYFILE);
266
289
fprintf(stdout, "The Error is: %s\n",
267
290
safer_gnutls_strerror(ret));
271
//Gnutls server initialization
294
//GnuTLS server initialization
272
295
if ((ret = gnutls_dh_params_init (&es->dh_params))
273
296
!= GNUTLS_E_SUCCESS) {
274
297
fprintf (stderr, "Error in dh parameter initialization: %s\n",
275
298
safer_gnutls_strerror(ret));
279
302
if ((ret = gnutls_dh_params_generate2 (es->dh_params, DH_BITS))
280
303
!= GNUTLS_E_SUCCESS) {
281
304
fprintf (stderr, "Error in prime generation: %s\n",
282
305
safer_gnutls_strerror(ret));
286
309
gnutls_certificate_set_dh_params (es->cred, es->dh_params);
288
// Gnutls session creation
311
// GnuTLS session creation
289
312
if ((ret = gnutls_init (&es->session, GNUTLS_SERVER))
290
313
!= GNUTLS_E_SUCCESS){
291
fprintf(stderr, "Error in gnutls session initialization: %s\n",
314
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
292
315
safer_gnutls_strerror(ret));
295
318
if ((ret = gnutls_priority_set_direct (es->session, "NORMAL", &err))
296
319
!= GNUTLS_E_SUCCESS) {
297
320
fprintf(stderr, "Syntax error at: %s\n", err);
298
fprintf(stderr, "Gnutls error: %s\n",
321
fprintf(stderr, "GnuTLS error: %s\n",
299
322
safer_gnutls_strerror(ret));
303
326
if ((ret = gnutls_credentials_set
304
327
(es->session, GNUTLS_CRD_CERTIFICATE, es->cred))
305
328
!= GNUTLS_E_SUCCESS) {
307
330
safer_gnutls_strerror(ret));
311
334
/* ignore client certificate if any. */
312
gnutls_certificate_server_set_request (es->session, GNUTLS_CERT_IGNORE);
335
gnutls_certificate_server_set_request (es->session,
314
338
gnutls_dh_set_prime_bits (es->session, DH_BITS);
319
void empty_log(AvahiLogLevel level, const char *txt){}
343
void empty_log(__attribute__((unused)) AvahiLogLevel level,
344
__attribute__((unused)) const char *txt){}
321
int start_mandos_communication(char *ip, uint16_t port){
346
int start_mandos_communication(const char *ip, uint16_t port,
347
unsigned int if_index){
323
349
struct sockaddr_in6 to;
324
350
encrypted_session es;
338
366
perror("socket");
370
if(if_indextoname(if_index, interface) == NULL){
372
perror("if_indextoname");
343
378
fprintf(stderr, "Binding to interface %s\n", interface);
346
ret = setsockopt(tcp_sd, SOL_SOCKET, SO_BINDTODEVICE, interface, 5);
348
perror("setsockopt bindtodevice");
352
memset(&to,0,sizeof(to));
381
memset(&to,0,sizeof(to)); /* Spurious warning */
353
382
to.sin6_family = AF_INET6;
354
383
ret = inet_pton(AF_INET6, ip, &to.sin6_addr);
383
gnutls_transport_set_ptr (es.session, (gnutls_transport_ptr_t) tcp_sd);
412
gnutls_transport_set_ptr (es.session,
413
(gnutls_transport_ptr_t) tcp_sd);
386
fprintf(stderr, "Establishing tls session with %s\n", ip);
416
fprintf(stderr, "Establishing TLS session with %s\n", ip);
390
419
ret = gnutls_handshake (es.session);
392
421
if (ret != GNUTLS_E_SUCCESS){
393
fprintf(stderr, "\n*** Handshake failed ***\n");
423
fprintf(stderr, "\n*** Handshake failed ***\n");
399
//Retrieve gpg packet that contains the wanted password
430
//Retrieve OpenPGP packet that contains the wanted password
402
fprintf(stderr, "Retrieving pgp encrypted password from %s\n", ip);
433
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
435
fprintf(stderr, "Unknown error while reading data from encrypted session with mandos server\n");
467
fprintf(stderr, "Unknown error while reading data from"
468
" encrypted session with mandos server\n");
437
470
gnutls_bye (es.session, GNUTLS_SHUT_RDWR);
441
buffer_length += ret;
474
buffer_length += (size_t) ret;
445
478
if (buffer_length > 0){
446
if ((decrypted_buffer_size = gpg_packet_decrypt(buffer, buffer_length, &decrypted_buffer, CERT_ROOT)) >= 0){
447
fwrite (decrypted_buffer, 1, decrypted_buffer_size, stdout);
479
decrypted_buffer_size = pgp_packet_decrypt(buffer,
483
if (decrypted_buffer_size >= 0){
484
while(written < decrypted_buffer_size){
485
ret = (int)fwrite (decrypted_buffer + written, 1,
486
(size_t)decrypted_buffer_size - written,
488
if(ret == 0 and ferror(stdout)){
490
fprintf(stderr, "Error writing encrypted data: %s\n",
496
written += (size_t)ret;
448
498
free(decrypted_buffer);
481
531
const char *host_name,
482
532
const AvahiAddress *address,
484
AvahiStringList *txt,
485
AvahiLookupResultFlags flags,
534
AVAHI_GCC_UNUSED AvahiStringList *txt,
535
AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
486
536
AVAHI_GCC_UNUSED void* userdata) {
490
/* Called whenever a service has been resolved successfully or timed out */
493
case AVAHI_RESOLVER_FAILURE:
494
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)));
497
case AVAHI_RESOLVER_FOUND: {
498
char ip[AVAHI_ADDRESS_STR_MAX];
499
avahi_address_snprint(ip, sizeof(ip), address);
501
fprintf(stderr, "Mandos server found at %s on port %d\n", ip, port);
503
int ret = start_mandos_communication(ip, port);
538
assert(r); /* Spurious warning */
540
/* Called whenever a service has been resolved successfully or
545
case AVAHI_RESOLVER_FAILURE:
546
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
547
" type '%s' in domain '%s': %s\n", name, type, domain,
548
avahi_strerror(avahi_server_errno(server)));
551
case AVAHI_RESOLVER_FOUND:
553
char ip[AVAHI_ADDRESS_STR_MAX];
554
avahi_address_snprint(ip, sizeof(ip), address);
556
fprintf(stderr, "Mandos server \"%s\" found on %s (%s) on"
557
" port %d\n", name, host_name, ip, port);
559
int ret = start_mandos_communication(ip, port,
560
(unsigned int) interface);
511
avahi_s_service_resolver_free(r);
566
avahi_s_service_resolver_free(r);
514
569
static void browse_callback(
523
578
void* userdata) {
525
580
AvahiServer *s = userdata;
528
/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
581
assert(b); /* Spurious warning */
583
/* Called whenever a new services becomes available on the LAN or
584
is removed from the LAN */
532
case AVAHI_BROWSER_FAILURE:
534
fprintf(stderr, "(Browser) %s\n", avahi_strerror(avahi_server_errno(server)));
535
avahi_simple_poll_quit(simple_poll);
538
case AVAHI_BROWSER_NEW:
539
/* We ignore the returned resolver object. In the callback
540
function we free it. If the server is terminated before
541
the callback function is called the server will free
542
the resolver for us. */
544
if (!(avahi_s_service_resolver_new(s, interface, protocol, name, type, domain, AVAHI_PROTO_INET6, 0, resolve_callback, s)))
545
fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(s)));
549
case AVAHI_BROWSER_REMOVE:
552
case AVAHI_BROWSER_ALL_FOR_NOW:
553
case AVAHI_BROWSER_CACHE_EXHAUSTED:
588
case AVAHI_BROWSER_FAILURE:
590
fprintf(stderr, "(Browser) %s\n",
591
avahi_strerror(avahi_server_errno(server)));
592
avahi_simple_poll_quit(simple_poll);
595
case AVAHI_BROWSER_NEW:
596
/* We ignore the returned resolver object. In the callback
597
function we free it. If the server is terminated before
598
the callback function is called the server will free
599
the resolver for us. */
601
if (!(avahi_s_service_resolver_new(s, interface, protocol, name,
603
AVAHI_PROTO_INET6, 0,
604
resolve_callback, s)))
605
fprintf(stderr, "Failed to resolve service '%s': %s\n", name,
606
avahi_strerror(avahi_server_errno(s)));
609
case AVAHI_BROWSER_REMOVE:
612
case AVAHI_BROWSER_ALL_FOR_NOW:
613
case AVAHI_BROWSER_CACHE_EXHAUSTED:
563
623
int returncode = EXIT_SUCCESS;
624
const char *interface = "eth0";
566
627
static struct option long_options[] = {
567
628
{"debug", no_argument, (int *)&debug, 1},
568
629
{"interface", required_argument, 0, 'i'},
571
632
int option_index = 0;
572
ret = getopt_long (argc, argv, "i:", long_options, &option_index);
633
ret = getopt_long (argc, argv, "i:", long_options,
608
670
config.publish_domain = 0;
610
672
/* Allocate a new server */
611
server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
673
server = avahi_server_new(avahi_simple_poll_get(simple_poll),
674
&config, NULL, NULL, &error);
613
676
/* Free the configuration data */
614
677
avahi_server_config_free(&config);
616
679
/* Check if creating the server object succeeded */
618
fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
681
fprintf(stderr, "Failed to create server: %s\n",
682
avahi_strerror(error));
619
683
returncode = EXIT_FAILURE;
623
687
/* Create the service browser */
624
if (!(sb = avahi_s_service_browser_new(server, if_nametoindex("eth0"), AVAHI_PROTO_INET6, "_mandos._tcp", NULL, 0, browse_callback, server))) {
625
fprintf(stderr, "Failed to create service browser: %s\n", avahi_strerror(avahi_server_errno(server)));
688
sb = avahi_s_service_browser_new(server,
690
if_nametoindex(interface),
692
"_mandos._tcp", NULL, 0,
693
browse_callback, server);
695
fprintf(stderr, "Failed to create service browser: %s\n",
696
avahi_strerror(avahi_server_errno(server)));
626
697
returncode = EXIT_FAILURE;