9
9
* "browse_callback", and parts of "main".
11
11
* Everything else is
12
* Copyright © 2008,2009 Teddy Hogeborn
13
* Copyright © 2008,2009 Björn Påhlsson
12
* Copyright © 2008-2011 Teddy Hogeborn
13
* Copyright © 2008-2011 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, EXIT_FAILURE,
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
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() */
66
#include <time.h> /* nanosleep(), time(), sleep() */
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(), setuid(),
74
getuid(), getgid(), seteuid(),
76
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
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, sigaction,
83
sigaction(), SIGTERM, sig_atomic_t,
85
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
87
89
#include <sys/klog.h> /* klogctl() */
142
146
.dh_bits = 1024, .priority = "SECURE256"
143
147
":!CTYPE-X.509:+CTYPE-OPENPGP" };
149
sig_atomic_t quit_now = 0;
150
int signal_received = 0;
146
153
* Make additional room in "buffer" for at least BUFFER_SIZE more
147
154
* bytes. "buffer_capacity" is how much is currently allocated,
474
481
static int init_gnutls_session(gnutls_session_t *session){
476
483
/* GnuTLS session creation */
477
ret = gnutls_init(session, GNUTLS_SERVER);
485
ret = gnutls_init(session, GNUTLS_SERVER);
489
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
478
490
if(ret != GNUTLS_E_SUCCESS){
479
491
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
480
492
safer_gnutls_strerror(ret));
485
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
498
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
500
gnutls_deinit(*session);
503
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
486
504
if(ret != GNUTLS_E_SUCCESS){
487
505
fprintf(stderr, "Syntax error at: %s\n", err);
488
506
fprintf(stderr, "GnuTLS error: %s\n",
495
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
514
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
517
gnutls_deinit(*session);
520
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
497
521
if(ret != GNUTLS_E_SUCCESS){
498
522
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
499
523
safer_gnutls_strerror(ret));
518
541
static int start_mandos_communication(const char *ip, uint16_t port,
519
542
AvahiIfIndex if_index,
544
int ret, tcp_sd = -1;
524
547
struct sockaddr_in in;
525
548
struct sockaddr_in6 in6;
527
550
char *buffer = NULL;
528
char *decrypted_buffer;
551
char *decrypted_buffer = NULL;
529
552
size_t buffer_length = 0;
530
553
size_t buffer_capacity = 0;
531
ssize_t decrypted_buffer_size;
534
556
gnutls_session_t session;
535
557
int pf; /* Protocol family */
589
630
if(if_index == AVAHI_IF_UNSPEC){
590
631
fprintf(stderr, "An IPv6 link-local address is incomplete"
591
632
" without a network interface\n");
594
636
/* Set the network interface number as scope */
595
637
to.in6.sin6_scope_id = (uint32_t)if_index;
635
687
if(af == AF_INET6){
636
688
ret = connect(tcp_sd, &to.in6, sizeof(to));
638
690
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
693
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
645
706
const char *out = mandos_protocol_version;
670
737
fprintf(stderr, "Establishing TLS session with %s\n", ip);
673
745
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
676
753
ret = gnutls_handshake(session);
677
758
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
679
760
if(ret != GNUTLS_E_SUCCESS){
712
805
case GNUTLS_E_AGAIN:
714
807
case GNUTLS_E_REHANDSHAKE:
716
809
ret = gnutls_handshake(session);
717
815
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
719
817
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
720
818
gnutls_perror(ret);
726
824
fprintf(stderr, "Unknown error while reading data from"
727
825
" encrypted session with Mandos server\n");
729
826
gnutls_bye(session, GNUTLS_SHUT_RDWR);
738
836
fprintf(stderr, "Closing TLS session\n");
741
gnutls_bye(session, GNUTLS_SHUT_RDWR);
845
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
850
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
743
852
if(buffer_length > 0){
853
ssize_t decrypted_buffer_size;
744
854
decrypted_buffer_size = pgp_packet_decrypt(buffer,
746
856
&decrypted_buffer);
747
857
if(decrypted_buffer_size >= 0){
749
860
while(written < (size_t) decrypted_buffer_size){
750
866
ret = (int)fwrite(decrypted_buffer + written, 1,
751
867
(size_t)decrypted_buffer_size - written,
753
869
if(ret == 0 and ferror(stdout)){
755
872
fprintf(stderr, "Error writing encrypted data: %s\n",
756
873
strerror(errno));
761
878
written += (size_t)ret;
763
free(decrypted_buffer);
771
884
/* Shutdown procedure */
775
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
889
free(decrypted_buffer);
892
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
900
gnutls_deinit(session);
779
gnutls_deinit(session);
878
sig_atomic_t quit_now = 0;
880
1013
/* stop main loop after sigterm has been called */
881
static void handle_sigterm(__attribute__((unused)) int sig){
1014
static void handle_sigterm(int sig){
1019
signal_received = sig;
886
1020
int old_errno = errno;
887
1021
if(mc.simple_poll != NULL){
888
1022
avahi_simple_poll_quit(mc.simple_poll);
890
1024
errno = old_errno;
1028
* This function determines if a directory entry in /sys/class/net
1029
* corresponds to an acceptable network device.
1030
* (This function is passed to scandir(3) as a filter function.)
1032
int good_interface(const struct dirent *if_entry){
1034
char *flagname = NULL;
1035
if(if_entry->d_name[0] == '.'){
1038
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1044
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1051
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1052
/* read line from flags_fd */
1053
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1054
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1055
flagstring[(size_t)to_read] = '\0';
1056
if(flagstring == NULL){
1062
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1079
tmpmax = strtoimax(flagstring, &tmp, 0);
1080
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1081
and not (isspace(*tmp)))
1082
or tmpmax != (ifreq_flags)tmpmax){
1084
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1085
flagstring, if_entry->d_name);
1091
ifreq_flags flags = (ifreq_flags)tmpmax;
1092
/* Reject the loopback device */
1093
if(flags & IFF_LOOPBACK){
1095
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1100
/* Accept point-to-point devices only if connect_to is specified */
1101
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1103
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1108
/* Otherwise, reject non-broadcast-capable devices */
1109
if(not (flags & IFF_BROADCAST)){
1111
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1116
/* Reject non-ARP interfaces (including dummy interfaces) */
1117
if(flags & IFF_NOARP){
1119
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1124
/* Accept this device */
1126
fprintf(stderr, "Interface \"%s\" is acceptable\n",
893
1132
int main(int argc, char *argv[]){
894
1133
AvahiSServiceBrowser *sb = NULL;
897
1136
intmax_t tmpmax;
899
1138
int exitcode = EXIT_SUCCESS;
900
const char *interface = "eth0";
1139
const char *interface = "";
901
1140
struct ifreq network;
1142
bool take_down_interface = false;
905
char *connect_to = NULL;
906
1145
char tempdir[] = "/tmp/mandosXXXXXX";
907
1146
bool tempdir_created = false;
908
1147
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
913
1152
bool gpgme_initialized = false;
914
1153
float delay = 2.5f;
916
struct sigaction old_sigterm_action;
1155
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
917
1156
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1161
/* Lower any group privileges we might have, just to be safe */
1168
/* Lower user privileges (temporarily) */
920
1180
struct argp_option options[] = {
921
1181
{ .name = "debug", .key = 128,
950
1210
.arg = "SECONDS",
951
1211
.doc = "Maximum delay to wait for interface startup",
1214
* These reproduce what we would get without ARGP_NO_HELP
1216
{ .name = "help", .key = '?',
1217
.doc = "Give this help list", .group = -1 },
1218
{ .name = "usage", .key = -3,
1219
.doc = "Give a short usage message", .group = -1 },
1220
{ .name = "version", .key = 'V',
1221
.doc = "Print program version", .group = -1 },
953
1222
{ .name = NULL }
956
1225
error_t parse_opt(int key, char *arg,
957
1226
struct argp_state *state){
959
1229
case 128: /* --debug */
976
1246
tmpmax = strtoimax(arg, &tmp, 10);
977
1247
if(errno != 0 or tmp == arg or *tmp != '\0'
978
1248
or tmpmax != (typeof(mc.dh_bits))tmpmax){
979
fprintf(stderr, "Bad number of DH bits\n");
1249
argp_error(state, "Bad number of DH bits");
982
1251
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
989
1258
delay = strtof(arg, &tmp);
990
1259
if(errno != 0 or tmp == arg or *tmp != '\0'){
991
fprintf(stderr, "Bad delay\n");
1260
argp_error(state, "Bad delay");
1264
* These reproduce what we would get without ARGP_NO_HELP
1266
case '?': /* --help */
1267
argp_state_help(state, state->out_stream,
1268
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1269
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1270
case -3: /* --usage */
1271
argp_state_help(state, state->out_stream,
1272
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1273
case 'V': /* --version */
1274
fprintf(state->out_stream, "%s\n", argp_program_version);
1275
exit(argp_err_exit_status);
1000
1278
return ARGP_ERR_UNKNOWN;
1005
1283
struct argp argp = { .options = options, .parser = parse_opt,
1006
1284
.args_doc = "",
1007
1285
.doc = "Mandos client -- Get and decrypt"
1008
1286
" passwords from a Mandos server" };
1009
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1010
if(ret == ARGP_ERR_UNKNOWN){
1011
fprintf(stderr, "Unknown error while parsing arguments\n");
1012
exitcode = EXIT_FAILURE;
1287
ret = argp_parse(&argp, argc, argv,
1288
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1295
perror("argp_parse");
1296
exitcode = EX_OSERR;
1299
exitcode = EX_USAGE;
1018
1305
avahi_set_log_function(empty_log);
1308
if(interface[0] == '\0'){
1309
struct dirent **direntries;
1310
ret = scandir(sys_class_net, &direntries, good_interface,
1313
/* Pick the first good interface */
1314
interface = strdup(direntries[0]->d_name);
1316
fprintf(stderr, "Using interface \"%s\"\n", interface);
1318
if(interface == NULL){
1321
exitcode = EXIT_FAILURE;
1327
fprintf(stderr, "Could not find a network interface\n");
1328
exitcode = EXIT_FAILURE;
1021
1333
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1022
1334
from the signal handler */
1033
1345
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1035
1347
perror("sigaddset");
1036
exitcode = EXIT_FAILURE;
1348
exitcode = EX_OSERR;
1039
1351
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1041
1353
perror("sigaddset");
1042
exitcode = EXIT_FAILURE;
1354
exitcode = EX_OSERR;
1045
1357
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1047
1359
perror("sigaddset");
1048
exitcode = EXIT_FAILURE;
1051
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1053
perror("sigaction");
1054
exitcode = EXIT_FAILURE;
1360
exitcode = EX_OSERR;
1363
/* Need to check if the handler is SIG_IGN before handling:
1364
| [[info:libc:Initial Signal Actions]] |
1365
| [[info:libc:Basic Signal Handling]] |
1367
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1369
perror("sigaction");
1372
if(old_sigterm_action.sa_handler != SIG_IGN){
1373
ret = sigaction(SIGINT, &sigterm_action, NULL);
1375
perror("sigaction");
1376
exitcode = EX_OSERR;
1380
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1382
perror("sigaction");
1385
if(old_sigterm_action.sa_handler != SIG_IGN){
1386
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1388
perror("sigaction");
1389
exitcode = EX_OSERR;
1393
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1395
perror("sigaction");
1398
if(old_sigterm_action.sa_handler != SIG_IGN){
1399
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1401
perror("sigaction");
1402
exitcode = EX_OSERR;
1058
1407
/* If the interface is down, bring it up */
1059
if(interface[0] != '\0'){
1408
if(strcmp(interface, "none") != 0){
1409
if_index = (AvahiIfIndex) if_nametoindex(interface);
1411
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1412
exitcode = EX_UNAVAILABLE;
1420
/* Re-raise priviliges */
1060
1427
#ifdef __linux__
1061
1428
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1062
messages to mess up the prompt */
1429
messages about the network interface to mess up the prompt */
1063
1430
ret = klogctl(8, NULL, 5);
1064
1431
bool restore_loglevel = true;
1096
1469
#endif /* __linux__ */
1097
exitcode = EXIT_FAILURE;
1470
exitcode = EX_OSERR;
1471
/* Lower privileges */
1100
1479
if((network.ifr_flags & IFF_UP) == 0){
1101
1480
network.ifr_flags |= IFF_UP;
1481
take_down_interface = true;
1102
1482
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1104
perror("ioctl SIOCSIFFLAGS");
1105
exitcode = EXIT_FAILURE;
1484
take_down_interface = false;
1485
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1486
exitcode = EX_OSERR;
1106
1487
#ifdef __linux__
1107
1488
if(restore_loglevel){
1108
1489
ret = klogctl(7, NULL, 0);
1143
1533
#endif /* __linux__ */
1534
/* Lower privileges */
1536
if(take_down_interface){
1537
/* Lower privileges */
1543
/* Lower privileges permanently */
1160
1555
ret = init_gnutls_global(pubkey, seckey);
1162
1557
fprintf(stderr, "init_gnutls_global failed\n");
1163
exitcode = EXIT_FAILURE;
1558
exitcode = EX_UNAVAILABLE;
1166
1561
gnutls_initialized = true;
1568
tempdir_created = true;
1169
1569
if(mkdtemp(tempdir) == NULL){
1570
tempdir_created = false;
1170
1571
perror("mkdtemp");
1173
tempdir_created = true;
1175
1579
if(not init_gpgme(pubkey, seckey, tempdir)){
1176
1580
fprintf(stderr, "init_gpgme failed\n");
1177
exitcode = EXIT_FAILURE;
1581
exitcode = EX_UNAVAILABLE;
1180
1584
gpgme_initialized = true;
1183
if(interface[0] != '\0'){
1184
if_index = (AvahiIfIndex) if_nametoindex(interface);
1186
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1187
exitcode = EXIT_FAILURE;
1192
1591
if(connect_to != NULL){
1195
1594
char *address = strrchr(connect_to, ':');
1196
1595
if(address == NULL){
1197
1596
fprintf(stderr, "No colon in address\n");
1198
exitcode = EXIT_FAILURE;
1597
exitcode = EX_USAGE;
1203
1607
tmpmax = strtoimax(address+1, &tmp, 10);
1204
1608
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1205
1609
or tmpmax != (uint16_t)tmpmax){
1206
1610
fprintf(stderr, "Bad port number\n");
1207
exitcode = EXIT_FAILURE;
1611
exitcode = EX_USAGE;
1210
1619
port = (uint16_t)tmpmax;
1211
1620
*address = '\0';
1212
1621
address = connect_to;
1220
ret = start_mandos_communication(address, port, if_index, af);
1222
exitcode = EXIT_FAILURE;
1634
while(not quit_now){
1635
ret = start_mandos_communication(address, port, if_index, af);
1636
if(quit_now or ret == 0){
1224
1643
exitcode = EXIT_SUCCESS;
1230
1654
AvahiServerConfig config;
1231
1655
/* Do not publish any local Zeroconf records */
1297
1729
gpgme_release(mc.ctx);
1732
/* Take down the network interface */
1733
if(take_down_interface){
1734
/* Re-raise priviliges */
1741
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1743
perror("ioctl SIOCGIFFLAGS");
1744
} else if(network.ifr_flags & IFF_UP) {
1745
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1746
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1748
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1751
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1755
/* Lower privileges permanently */
1300
1764
/* Removes the temp directory used by GPGME */
1301
1765
if(tempdir_created){
1809
sigemptyset(&old_sigterm_action.sa_mask);
1810
old_sigterm_action.sa_handler = SIG_DFL;
1811
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1812
&old_sigterm_action,
1815
perror("sigaction");
1818
ret = raise(signal_received);
1819
} while(ret != 0 and errno == EINTR);
1824
TEMP_FAILURE_RETRY(pause());
1344
1827
return exitcode;