9
9
* "browse_callback", and parts of "main".
11
11
* Everything else is
12
* Copyright © 2008-2011 Teddy Hogeborn
13
* Copyright © 2008-2011 Björn Påhlsson
12
* Copyright © 2008,2009 Teddy Hogeborn
13
* Copyright © 2008,2009 Björn Påhlsson
15
15
* This program is free software: you can redistribute it and/or
16
16
* modify it under the terms of the GNU General Public License as
43
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
48
48
#include <stdbool.h> /* bool, false, true */
49
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
50
strerror(), asprintf(), strcpy() */
64
64
#include <assert.h> /* assert() */
65
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time(), sleep() */
66
#include <time.h> /* nanosleep(), time() */
67
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
68
SIOCSIFFLAGS, if_indextoname(),
69
69
if_nametoindex(), IF_NAMESIZE */
71
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
76
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
74
getuid(), getgid(), setuid(),
76
#include <arpa/inet.h> /* inet_pton(), htons */
77
77
#include <iso646.h> /* not, or, and */
78
78
#include <argp.h> /* struct argp_option, error_t, struct
79
79
argp_state, struct argp,
80
80
argp_parse(), ARGP_KEY_ARG,
81
81
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
82
#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 */
83
sigaction(), SIGTERM, sigaction,
89
87
#include <sys/klog.h> /* klogctl() */
146
142
.dh_bits = 1024, .priority = "SECURE256"
147
143
":!CTYPE-X.509:+CTYPE-OPENPGP" };
149
sig_atomic_t quit_now = 0;
150
int signal_received = 0;
153
146
* Make additional room in "buffer" for at least BUFFER_SIZE more
154
147
* bytes. "buffer_capacity" is how much is currently allocated,
317
310
gpgme_recipient_t recipient;
318
311
recipient = result->recipients;
319
while(recipient != NULL){
320
fprintf(stderr, "Public key algorithm: %s\n",
321
gpgme_pubkey_algo_name(recipient->pubkey_algo));
322
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
323
fprintf(stderr, "Secret key available: %s\n",
324
recipient->status == GPG_ERR_NO_SECKEY
326
recipient = recipient->next;
313
while(recipient != NULL){
314
fprintf(stderr, "Public key algorithm: %s\n",
315
gpgme_pubkey_algo_name(recipient->pubkey_algo));
316
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
317
fprintf(stderr, "Secret key available: %s\n",
318
recipient->status == GPG_ERR_NO_SECKEY
320
recipient = recipient->next;
425
420
/* OpenPGP credentials */
426
ret = gnutls_certificate_allocate_credentials(&mc.cred);
421
gnutls_certificate_allocate_credentials(&mc.cred);
427
422
if(ret != GNUTLS_E_SUCCESS){
428
fprintf(stderr, "GnuTLS memory error: %s\n",
423
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
429
427
safer_gnutls_strerror(ret));
430
428
gnutls_global_deinit();
478
476
static int init_gnutls_session(gnutls_session_t *session){
480
478
/* GnuTLS session creation */
482
ret = gnutls_init(session, GNUTLS_SERVER);
486
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
479
ret = gnutls_init(session, GNUTLS_SERVER);
487
480
if(ret != GNUTLS_E_SUCCESS){
488
481
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
489
482
safer_gnutls_strerror(ret));
495
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
497
gnutls_deinit(*session);
500
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
487
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
501
488
if(ret != GNUTLS_E_SUCCESS){
502
489
fprintf(stderr, "Syntax error at: %s\n", err);
503
490
fprintf(stderr, "GnuTLS error: %s\n",
511
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
514
gnutls_deinit(*session);
517
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
497
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
518
499
if(ret != GNUTLS_E_SUCCESS){
519
500
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
520
501
safer_gnutls_strerror(ret));
538
520
static int start_mandos_communication(const char *ip, uint16_t port,
539
521
AvahiIfIndex if_index,
541
int ret, tcp_sd = -1;
544
526
struct sockaddr_in in;
545
527
struct sockaddr_in6 in6;
547
529
char *buffer = NULL;
548
char *decrypted_buffer = NULL;
530
char *decrypted_buffer;
549
531
size_t buffer_length = 0;
550
532
size_t buffer_capacity = 0;
533
ssize_t decrypted_buffer_size;
553
536
gnutls_session_t session;
554
537
int pf; /* Protocol family */
627
591
if(if_index == AVAHI_IF_UNSPEC){
628
592
fprintf(stderr, "An IPv6 link-local address is incomplete"
629
593
" without a network interface\n");
633
596
/* Set the network interface number as scope */
634
597
to.in6.sin6_scope_id = (uint32_t)if_index;
684
637
if(af == AF_INET6){
685
638
ret = connect(tcp_sd, &to.in6, sizeof(to));
687
640
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
690
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
703
647
const char *out = mandos_protocol_version;
734
672
fprintf(stderr, "Establishing TLS session with %s\n", ip);
742
675
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
750
678
ret = gnutls_handshake(session);
755
679
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
757
681
if(ret != GNUTLS_E_SUCCESS){
802
714
case GNUTLS_E_AGAIN:
804
716
case GNUTLS_E_REHANDSHAKE:
806
718
ret = gnutls_handshake(session);
812
719
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
814
721
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
815
722
gnutls_perror(ret);
821
728
fprintf(stderr, "Unknown error while reading data from"
822
729
" encrypted session with Mandos server\n");
823
731
gnutls_bye(session, GNUTLS_SHUT_RDWR);
833
740
fprintf(stderr, "Closing TLS session\n");
842
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
847
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
743
gnutls_bye(session, GNUTLS_SHUT_RDWR);
849
745
if(buffer_length > 0){
850
ssize_t decrypted_buffer_size;
851
746
decrypted_buffer_size = pgp_packet_decrypt(buffer,
853
748
&decrypted_buffer);
854
749
if(decrypted_buffer_size >= 0){
857
751
while(written < (size_t) decrypted_buffer_size){
863
752
ret = (int)fwrite(decrypted_buffer + written, 1,
864
753
(size_t)decrypted_buffer_size - written,
866
755
if(ret == 0 and ferror(stdout)){
869
757
fprintf(stderr, "Error writing encrypted data: %s\n",
870
758
strerror(errno));
875
763
written += (size_t)ret;
765
free(decrypted_buffer);
881
773
/* Shutdown procedure */
886
free(decrypted_buffer);
889
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
897
gnutls_deinit(session);
777
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
781
gnutls_deinit(session);
880
sig_atomic_t quit_now = 0;
1010
882
/* stop main loop after sigterm has been called */
1011
static void handle_sigterm(int sig){
883
static void handle_sigterm(__attribute__((unused)) int sig){
1016
signal_received = sig;
1017
888
int old_errno = errno;
1018
889
if(mc.simple_poll != NULL){
1019
890
avahi_simple_poll_quit(mc.simple_poll);
1021
892
errno = old_errno;
1025
* This function determines if a directory entry in /sys/class/net
1026
* corresponds to an acceptable network device.
1027
* (This function is passed to scandir(3) as a filter function.)
1029
int good_interface(const struct dirent *if_entry){
1031
char *flagname = NULL;
1032
if(if_entry->d_name[0] == '.'){
1035
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1041
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1048
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1049
/* read line from flags_fd */
1050
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1051
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1052
flagstring[(size_t)to_read] = '\0';
1053
if(flagstring == NULL){
1059
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1076
tmpmax = strtoimax(flagstring, &tmp, 0);
1077
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1078
and not (isspace(*tmp)))
1079
or tmpmax != (ifreq_flags)tmpmax){
1081
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1082
flagstring, if_entry->d_name);
1088
ifreq_flags flags = (ifreq_flags)tmpmax;
1089
/* Reject the loopback device */
1090
if(flags & IFF_LOOPBACK){
1092
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1097
/* Accept point-to-point devices only if connect_to is specified */
1098
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1100
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1105
/* Otherwise, reject non-broadcast-capable devices */
1106
if(not (flags & IFF_BROADCAST)){
1108
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1113
/* Reject non-ARP interfaces (including dummy interfaces) */
1114
if(flags & IFF_NOARP){
1116
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1121
/* Accept this device */
1123
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1129
895
int main(int argc, char *argv[]){
1130
896
AvahiSServiceBrowser *sb = NULL;
1133
899
intmax_t tmpmax;
1135
901
int exitcode = EXIT_SUCCESS;
1136
const char *interface = "";
902
const char *interface = "eth0";
1137
903
struct ifreq network;
1139
bool take_down_interface = false;
907
char *connect_to = NULL;
1142
908
char tempdir[] = "/tmp/mandosXXXXXX";
1143
909
bool tempdir_created = false;
1144
910
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1149
915
bool gpgme_initialized = false;
1150
916
float delay = 2.5f;
1152
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
918
struct sigaction old_sigterm_action;
1153
919
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1158
/* Lower any group privileges we might have, just to be safe */
1165
/* Lower user privileges (temporarily) */
1177
922
struct argp_option options[] = {
1178
923
{ .name = "debug", .key = 128,
1207
952
.arg = "SECONDS",
1208
953
.doc = "Maximum delay to wait for interface startup",
1211
* These reproduce what we would get without ARGP_NO_HELP
1213
{ .name = "help", .key = '?',
1214
.doc = "Give this help list", .group = -1 },
1215
{ .name = "usage", .key = -3,
1216
.doc = "Give a short usage message", .group = -1 },
1217
{ .name = "version", .key = 'V',
1218
.doc = "Print program version", .group = -1 },
1219
955
{ .name = NULL }
1222
958
error_t parse_opt(int key, char *arg,
1223
959
struct argp_state *state){
1226
961
case 128: /* --debug */
1243
978
tmpmax = strtoimax(arg, &tmp, 10);
1244
979
if(errno != 0 or tmp == arg or *tmp != '\0'
1245
980
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1246
argp_error(state, "Bad number of DH bits");
981
fprintf(stderr, "Bad number of DH bits\n");
1248
984
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1255
991
delay = strtof(arg, &tmp);
1256
992
if(errno != 0 or tmp == arg or *tmp != '\0'){
1257
argp_error(state, "Bad delay");
993
fprintf(stderr, "Bad delay\n");
1261
* These reproduce what we would get without ARGP_NO_HELP
1263
case '?': /* --help */
1264
argp_state_help(state, state->out_stream,
1265
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1266
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1267
case -3: /* --usage */
1268
argp_state_help(state, state->out_stream,
1269
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1270
case 'V': /* --version */
1271
fprintf(state->out_stream, "%s\n", argp_program_version);
1272
exit(argp_err_exit_status);
1275
1002
return ARGP_ERR_UNKNOWN;
1280
1007
struct argp argp = { .options = options, .parser = parse_opt,
1281
1008
.args_doc = "",
1282
1009
.doc = "Mandos client -- Get and decrypt"
1283
1010
" passwords from a Mandos server" };
1284
ret = argp_parse(&argp, argc, argv,
1285
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1292
perror("argp_parse");
1293
exitcode = EX_OSERR;
1296
exitcode = EX_USAGE;
1011
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1012
if(ret == ARGP_ERR_UNKNOWN){
1013
fprintf(stderr, "Unknown error while parsing arguments\n");
1014
exitcode = EXIT_FAILURE;
1302
1020
avahi_set_log_function(empty_log);
1305
if(interface[0] == '\0'){
1306
struct dirent **direntries;
1307
ret = scandir(sys_class_net, &direntries, good_interface,
1310
/* Pick the first good interface */
1311
interface = strdup(direntries[0]->d_name);
1313
fprintf(stderr, "Using interface \"%s\"\n", interface);
1315
if(interface == NULL){
1318
exitcode = EXIT_FAILURE;
1324
fprintf(stderr, "Could not find a network interface\n");
1325
exitcode = EXIT_FAILURE;
1330
1023
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1331
1024
from the signal handler */
1342
1035
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1344
1037
perror("sigaddset");
1345
exitcode = EX_OSERR;
1038
exitcode = EXIT_FAILURE;
1348
1041
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1350
1043
perror("sigaddset");
1351
exitcode = EX_OSERR;
1044
exitcode = EXIT_FAILURE;
1354
1047
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1356
1049
perror("sigaddset");
1357
exitcode = EX_OSERR;
1360
/* Need to check if the handler is SIG_IGN before handling:
1361
| [[info:libc:Initial Signal Actions]] |
1362
| [[info:libc:Basic Signal Handling]] |
1364
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1366
perror("sigaction");
1369
if(old_sigterm_action.sa_handler != SIG_IGN){
1370
ret = sigaction(SIGINT, &sigterm_action, NULL);
1372
perror("sigaction");
1373
exitcode = EX_OSERR;
1377
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1379
perror("sigaction");
1382
if(old_sigterm_action.sa_handler != SIG_IGN){
1383
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1385
perror("sigaction");
1386
exitcode = EX_OSERR;
1390
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1392
perror("sigaction");
1395
if(old_sigterm_action.sa_handler != SIG_IGN){
1396
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1398
perror("sigaction");
1399
exitcode = EX_OSERR;
1050
exitcode = EXIT_FAILURE;
1053
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1055
perror("sigaction");
1056
exitcode = EXIT_FAILURE;
1404
1060
/* If the interface is down, bring it up */
1405
if(strcmp(interface, "none") != 0){
1406
if_index = (AvahiIfIndex) if_nametoindex(interface);
1408
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1409
exitcode = EX_UNAVAILABLE;
1417
/* Re-raise priviliges */
1061
if(interface[0] != '\0'){
1424
1062
#ifdef __linux__
1425
1063
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1426
messages about the network interface to mess up the prompt */
1064
messages to mess up the prompt */
1427
1065
ret = klogctl(8, NULL, 5);
1428
1066
bool restore_loglevel = true;
1466
1098
#endif /* __linux__ */
1467
exitcode = EX_OSERR;
1468
/* Lower privileges */
1099
exitcode = EXIT_FAILURE;
1476
1102
if((network.ifr_flags & IFF_UP) == 0){
1477
1103
network.ifr_flags |= IFF_UP;
1478
take_down_interface = true;
1479
1104
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1481
take_down_interface = false;
1482
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1483
exitcode = EX_OSERR;
1106
perror("ioctl SIOCSIFFLAGS");
1107
exitcode = EXIT_FAILURE;
1484
1108
#ifdef __linux__
1485
1109
if(restore_loglevel){
1486
1110
ret = klogctl(7, NULL, 0);
1530
1145
#endif /* __linux__ */
1531
/* Lower privileges */
1533
if(take_down_interface){
1534
/* Lower privileges */
1540
/* Lower privileges permanently */
1552
1162
ret = init_gnutls_global(pubkey, seckey);
1554
1164
fprintf(stderr, "init_gnutls_global failed\n");
1555
exitcode = EX_UNAVAILABLE;
1165
exitcode = EXIT_FAILURE;
1558
1168
gnutls_initialized = true;
1565
tempdir_created = true;
1566
1171
if(mkdtemp(tempdir) == NULL){
1567
tempdir_created = false;
1568
1172
perror("mkdtemp");
1175
tempdir_created = true;
1576
1177
if(not init_gpgme(pubkey, seckey, tempdir)){
1577
1178
fprintf(stderr, "init_gpgme failed\n");
1578
exitcode = EX_UNAVAILABLE;
1179
exitcode = EXIT_FAILURE;
1581
1182
gpgme_initialized = true;
1185
if(interface[0] != '\0'){
1186
if_index = (AvahiIfIndex) if_nametoindex(interface);
1188
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1189
exitcode = EXIT_FAILURE;
1588
1194
if(connect_to != NULL){
1591
1197
char *address = strrchr(connect_to, ':');
1592
1198
if(address == NULL){
1593
1199
fprintf(stderr, "No colon in address\n");
1594
exitcode = EX_USAGE;
1200
exitcode = EXIT_FAILURE;
1604
1205
tmpmax = strtoimax(address+1, &tmp, 10);
1605
1206
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1606
1207
or tmpmax != (uint16_t)tmpmax){
1607
1208
fprintf(stderr, "Bad port number\n");
1608
exitcode = EX_USAGE;
1209
exitcode = EXIT_FAILURE;
1616
1212
port = (uint16_t)tmpmax;
1617
1213
*address = '\0';
1618
1214
address = connect_to;
1631
while(not quit_now){
1632
ret = start_mandos_communication(address, port, if_index, af);
1633
if(quit_now or ret == 0){
1222
ret = start_mandos_communication(address, port, if_index, af);
1224
exitcode = EXIT_FAILURE;
1640
1226
exitcode = EXIT_SUCCESS;
1651
1232
AvahiServerConfig config;
1652
1233
/* Do not publish any local Zeroconf records */
1726
1299
gpgme_release(mc.ctx);
1729
/* Take down the network interface */
1730
if(take_down_interface){
1731
/* Re-raise priviliges */
1738
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1740
perror("ioctl SIOCGIFFLAGS");
1741
} else if(network.ifr_flags & IFF_UP) {
1742
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1743
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1745
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1748
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1752
/* Lower privileges permanently */
1761
1302
/* Removes the temp directory used by GPGME */
1762
1303
if(tempdir_created){
1806
sigemptyset(&old_sigterm_action.sa_mask);
1807
old_sigterm_action.sa_handler = SIG_DFL;
1808
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1809
&old_sigterm_action,
1812
perror("sigaction");
1815
ret = raise(signal_received);
1816
} while(ret != 0 and errno == EINTR);
1821
TEMP_FAILURE_RETRY(pause());
1824
1346
return exitcode;