32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
33
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
37
34
#define _FILE_OFFSET_BITS 64
40
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
43
39
stdout, ferror(), remove() */
44
40
#include <stdint.h> /* uint16_t, uint32_t */
45
41
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
42
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
48
44
#include <stdbool.h> /* bool, false, true */
49
45
#include <string.h> /* memset(), strcmp(), strlen(),
50
46
strerror(), asprintf(), strcpy() */
71
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
70
getuid(), getgid(), setuid(),
76
72
#include <arpa/inet.h> /* inet_pton(), htons */
77
73
#include <iso646.h> /* not, or, and */
78
74
#include <argp.h> /* struct argp_option, error_t, struct
80
76
argp_parse(), ARGP_KEY_ARG,
81
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
78
#include <signal.h> /* sigemptyset(), sigaddset(),
83
sigaction(), SIGTERM, sig_atomic_t,
85
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
79
sigaction(), SIGTERM, sigaction,
89
83
#include <sys/klog.h> /* klogctl() */
144
138
.dh_bits = 1024, .priority = "SECURE256"
145
139
":!CTYPE-X.509:+CTYPE-OPENPGP" };
147
sig_atomic_t quit_now = 0;
148
int signal_received = 0;
151
142
* Make additional room in "buffer" for at least BUFFER_SIZE more
152
143
* bytes. "buffer_capacity" is how much is currently allocated,
315
306
gpgme_recipient_t recipient;
316
307
recipient = result->recipients;
317
while(recipient != NULL){
318
fprintf(stderr, "Public key algorithm: %s\n",
319
gpgme_pubkey_algo_name(recipient->pubkey_algo));
320
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
321
fprintf(stderr, "Secret key available: %s\n",
322
recipient->status == GPG_ERR_NO_SECKEY
324
recipient = recipient->next;
309
while(recipient != NULL){
310
fprintf(stderr, "Public key algorithm: %s\n",
311
gpgme_pubkey_algo_name(recipient->pubkey_algo));
312
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
313
fprintf(stderr, "Secret key available: %s\n",
314
recipient->status == GPG_ERR_NO_SECKEY
316
recipient = recipient->next;
479
472
static int init_gnutls_session(gnutls_session_t *session){
481
474
/* GnuTLS session creation */
483
ret = gnutls_init(session, GNUTLS_SERVER);
487
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
475
ret = gnutls_init(session, GNUTLS_SERVER);
488
476
if(ret != GNUTLS_E_SUCCESS){
489
477
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
490
478
safer_gnutls_strerror(ret));
496
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
498
gnutls_deinit(*session);
501
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
483
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
502
484
if(ret != GNUTLS_E_SUCCESS){
503
485
fprintf(stderr, "Syntax error at: %s\n", err);
504
486
fprintf(stderr, "GnuTLS error: %s\n",
512
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
515
gnutls_deinit(*session);
518
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
493
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
519
495
if(ret != GNUTLS_E_SUCCESS){
520
496
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
521
497
safer_gnutls_strerror(ret));
526
502
/* ignore client certificate if any. */
527
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
503
gnutls_certificate_server_set_request(*session,
529
506
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
539
516
static int start_mandos_communication(const char *ip, uint16_t port,
540
517
AvahiIfIndex if_index,
542
int ret, tcp_sd = -1;
545
522
struct sockaddr_in in;
546
523
struct sockaddr_in6 in6;
548
525
char *buffer = NULL;
549
char *decrypted_buffer = NULL;
526
char *decrypted_buffer;
550
527
size_t buffer_length = 0;
551
528
size_t buffer_capacity = 0;
529
ssize_t decrypted_buffer_size;
554
532
gnutls_session_t session;
555
533
int pf; /* Protocol family */
587
557
tcp_sd = socket(pf, SOCK_STREAM, 0);
590
559
perror("socket");
600
563
memset(&to, 0, sizeof(to));
601
564
if(af == AF_INET6){
602
to.in6.sin6_family = (sa_family_t)af;
565
to.in6.sin6_family = (uint16_t)af;
603
566
ret = inet_pton(af, ip, &to.in6.sin6_addr);
604
567
} else { /* IPv4 */
605
568
to.in.sin_family = (sa_family_t)af;
606
569
ret = inet_pton(af, ip, &to.in.sin_addr);
610
572
perror("inet_pton");
616
576
fprintf(stderr, "Bad address: %s\n", ip);
620
579
if(af == AF_INET6){
621
580
to.in6.sin6_port = htons(port); /* Spurious warnings from
628
587
if(if_index == AVAHI_IF_UNSPEC){
629
588
fprintf(stderr, "An IPv6 link-local address is incomplete"
630
589
" without a network interface\n");
634
592
/* Set the network interface number as scope */
635
593
to.in6.sin6_scope_id = (uint32_t)if_index;
685
633
if(af == AF_INET6){
686
634
ret = connect(tcp_sd, &to.in6, sizeof(to));
688
636
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
692
639
perror("connect");
702
643
const char *out = mandos_protocol_version;
733
668
fprintf(stderr, "Establishing TLS session with %s\n", ip);
741
671
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
749
674
ret = gnutls_handshake(session);
754
675
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
756
677
if(ret != GNUTLS_E_SUCCESS){
801
710
case GNUTLS_E_AGAIN:
803
712
case GNUTLS_E_REHANDSHAKE:
805
714
ret = gnutls_handshake(session);
811
715
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
813
717
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
814
718
gnutls_perror(ret);
820
724
fprintf(stderr, "Unknown error while reading data from"
821
725
" encrypted session with Mandos server\n");
822
727
gnutls_bye(session, GNUTLS_SHUT_RDWR);
832
736
fprintf(stderr, "Closing TLS session\n");
841
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
846
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
739
gnutls_bye(session, GNUTLS_SHUT_RDWR);
848
741
if(buffer_length > 0){
849
ssize_t decrypted_buffer_size;
850
742
decrypted_buffer_size = pgp_packet_decrypt(buffer,
852
744
&decrypted_buffer);
853
745
if(decrypted_buffer_size >= 0){
856
747
while(written < (size_t) decrypted_buffer_size){
862
748
ret = (int)fwrite(decrypted_buffer + written, 1,
863
749
(size_t)decrypted_buffer_size - written,
865
751
if(ret == 0 and ferror(stdout)){
868
753
fprintf(stderr, "Error writing encrypted data: %s\n",
869
754
strerror(errno));
874
759
written += (size_t)ret;
761
free(decrypted_buffer);
880
769
/* Shutdown procedure */
885
free(decrypted_buffer);
888
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
896
gnutls_deinit(session);
773
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
777
gnutls_deinit(session);
876
sig_atomic_t quit_now = 0;
1009
878
/* stop main loop after sigterm has been called */
1010
static void handle_sigterm(int sig){
879
static void handle_sigterm(__attribute__((unused)) int sig){
1015
signal_received = sig;
1016
884
int old_errno = errno;
1017
885
if(mc.simple_poll != NULL){
1018
886
avahi_simple_poll_quit(mc.simple_poll);
1044
911
bool gpgme_initialized = false;
1045
912
float delay = 2.5f;
1047
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
914
struct sigaction old_sigterm_action;
1048
915
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1053
/* Lower any group privileges we might have, just to be safe */
1060
/* Lower user privileges (temporarily) */
1072
918
struct argp_option options[] = {
1073
919
{ .name = "debug", .key = 128,
1102
948
.arg = "SECONDS",
1103
949
.doc = "Maximum delay to wait for interface startup",
1106
* These reproduce what we would get without ARGP_NO_HELP
1108
{ .name = "help", .key = '?',
1109
.doc = "Give this help list", .group = -1 },
1110
{ .name = "usage", .key = -3,
1111
.doc = "Give a short usage message", .group = -1 },
1112
{ .name = "version", .key = 'V',
1113
.doc = "Print program version", .group = -1 },
1114
951
{ .name = NULL }
1117
954
error_t parse_opt(int key, char *arg,
1118
955
struct argp_state *state){
1121
957
case 128: /* --debug */
1138
974
tmpmax = strtoimax(arg, &tmp, 10);
1139
975
if(errno != 0 or tmp == arg or *tmp != '\0'
1140
976
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1141
argp_error(state, "Bad number of DH bits");
977
fprintf(stderr, "Bad number of DH bits\n");
1143
980
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1150
987
delay = strtof(arg, &tmp);
1151
988
if(errno != 0 or tmp == arg or *tmp != '\0'){
1152
argp_error(state, "Bad delay");
989
fprintf(stderr, "Bad delay\n");
1156
* These reproduce what we would get without ARGP_NO_HELP
1158
case '?': /* --help */
1159
argp_state_help(state, state->out_stream,
1160
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1161
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1162
case -3: /* --usage */
1163
argp_state_help(state, state->out_stream,
1164
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1165
case 'V': /* --version */
1166
fprintf(state->out_stream, "%s\n", argp_program_version);
1167
exit(argp_err_exit_status);
1170
998
return ARGP_ERR_UNKNOWN;
1175
1003
struct argp argp = { .options = options, .parser = parse_opt,
1176
1004
.args_doc = "",
1177
1005
.doc = "Mandos client -- Get and decrypt"
1178
1006
" passwords from a Mandos server" };
1179
ret = argp_parse(&argp, argc, argv,
1180
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1187
perror("argp_parse");
1188
exitcode = EX_OSERR;
1191
exitcode = EX_USAGE;
1007
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1008
if(ret == ARGP_ERR_UNKNOWN){
1009
fprintf(stderr, "Unknown error while parsing arguments\n");
1010
exitcode = EXIT_FAILURE;
1204
1023
mc.simple_poll = avahi_simple_poll_new();
1205
1024
if(mc.simple_poll == NULL){
1206
1025
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1207
exitcode = EX_UNAVAILABLE;
1026
exitcode = EXIT_FAILURE;
1212
1031
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1214
1033
perror("sigaddset");
1215
exitcode = EX_OSERR;
1034
exitcode = EXIT_FAILURE;
1218
1037
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1220
1039
perror("sigaddset");
1221
exitcode = EX_OSERR;
1040
exitcode = EXIT_FAILURE;
1224
1043
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1226
1045
perror("sigaddset");
1227
exitcode = EX_OSERR;
1230
/* Need to check if the handler is SIG_IGN before handling:
1231
| [[info:libc:Initial Signal Actions]] |
1232
| [[info:libc:Basic Signal Handling]] |
1234
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1236
perror("sigaction");
1239
if(old_sigterm_action.sa_handler != SIG_IGN){
1240
ret = sigaction(SIGINT, &sigterm_action, NULL);
1242
perror("sigaction");
1243
exitcode = EX_OSERR;
1247
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1249
perror("sigaction");
1252
if(old_sigterm_action.sa_handler != SIG_IGN){
1253
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1255
perror("sigaction");
1256
exitcode = EX_OSERR;
1260
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1262
perror("sigaction");
1265
if(old_sigterm_action.sa_handler != SIG_IGN){
1266
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1268
perror("sigaction");
1269
exitcode = EX_OSERR;
1046
exitcode = EXIT_FAILURE;
1049
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1051
perror("sigaction");
1052
exitcode = EXIT_FAILURE;
1274
1056
/* If the interface is down, bring it up */
1275
1057
if(interface[0] != '\0'){
1276
if_index = (AvahiIfIndex) if_nametoindex(interface);
1278
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1279
exitcode = EX_UNAVAILABLE;
1287
/* Re-raise priviliges */
1294
1058
#ifdef __linux__
1295
1059
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1296
messages about the network interface to mess up the prompt */
1060
messages to mess up the prompt */
1297
1061
ret = klogctl(8, NULL, 5);
1298
1062
bool restore_loglevel = true;
1336
1094
#endif /* __linux__ */
1337
exitcode = EX_OSERR;
1338
/* Lower privileges */
1095
exitcode = EXIT_FAILURE;
1346
1098
if((network.ifr_flags & IFF_UP) == 0){
1347
1099
network.ifr_flags |= IFF_UP;
1348
take_down_interface = true;
1349
1100
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1351
take_down_interface = false;
1352
1102
perror("ioctl SIOCSIFFLAGS");
1353
exitcode = EX_OSERR;
1103
exitcode = EXIT_FAILURE;
1354
1104
#ifdef __linux__
1355
1105
if(restore_loglevel){
1356
1106
ret = klogctl(7, NULL, 0);
1400
1141
#endif /* __linux__ */
1401
/* Lower privileges */
1403
if(take_down_interface){
1404
/* Lower privileges */
1410
/* Lower privileges permanently */
1422
1158
ret = init_gnutls_global(pubkey, seckey);
1424
1160
fprintf(stderr, "init_gnutls_global failed\n");
1425
exitcode = EX_UNAVAILABLE;
1161
exitcode = EXIT_FAILURE;
1428
1164
gnutls_initialized = true;
1435
tempdir_created = true;
1436
1167
if(mkdtemp(tempdir) == NULL){
1437
tempdir_created = false;
1438
1168
perror("mkdtemp");
1171
tempdir_created = true;
1446
1173
if(not init_gpgme(pubkey, seckey, tempdir)){
1447
1174
fprintf(stderr, "init_gpgme failed\n");
1448
exitcode = EX_UNAVAILABLE;
1175
exitcode = EXIT_FAILURE;
1451
1178
gpgme_initialized = true;
1181
if(interface[0] != '\0'){
1182
if_index = (AvahiIfIndex) if_nametoindex(interface);
1184
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1185
exitcode = EXIT_FAILURE;
1458
1190
if(connect_to != NULL){
1461
1193
char *address = strrchr(connect_to, ':');
1462
1194
if(address == NULL){
1463
1195
fprintf(stderr, "No colon in address\n");
1464
exitcode = EX_USAGE;
1196
exitcode = EXIT_FAILURE;
1474
1201
tmpmax = strtoimax(address+1, &tmp, 10);
1475
1202
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1476
1203
or tmpmax != (uint16_t)tmpmax){
1477
1204
fprintf(stderr, "Bad port number\n");
1478
exitcode = EX_USAGE;
1205
exitcode = EXIT_FAILURE;
1486
1208
port = (uint16_t)tmpmax;
1487
1209
*address = '\0';
1488
1210
address = connect_to;
1501
1218
ret = start_mandos_communication(address, port, if_index, af);
1507
exitcode = EX_NOHOST;
1510
exitcode = EX_USAGE;
1513
exitcode = EX_IOERR;
1516
exitcode = EX_PROTOCOL;
1519
exitcode = EX_OSERR;
1220
exitcode = EXIT_FAILURE;
1523
1222
exitcode = EXIT_SUCCESS;
1533
1228
AvahiServerConfig config;
1534
1229
/* Do not publish any local Zeroconf records */
1608
1295
gpgme_release(mc.ctx);
1611
/* Take down the network interface */
1612
if(take_down_interface){
1613
/* Re-raise priviliges */
1620
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1622
perror("ioctl SIOCGIFFLAGS");
1623
} else if(network.ifr_flags & IFF_UP) {
1624
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1625
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1627
perror("ioctl SIOCSIFFLAGS");
1630
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1634
/* Lower privileges permanently */
1643
1298
/* Removes the temp directory used by GPGME */
1644
1299
if(tempdir_created){
1688
sigemptyset(&old_sigterm_action.sa_mask);
1689
old_sigterm_action.sa_handler = SIG_DFL;
1690
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1691
&old_sigterm_action,
1694
perror("sigaction");
1697
ret = raise(signal_received);
1698
} while(ret != 0 and errno == EINTR);
1703
TEMP_FAILURE_RETRY(pause());
1706
1342
return exitcode;