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(),
74
getuid(), getgid(), setuid(),
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, 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() */
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;
481
476
static int init_gnutls_session(gnutls_session_t *session){
483
478
/* GnuTLS session creation */
485
ret = gnutls_init(session, GNUTLS_SERVER);
489
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
479
ret = gnutls_init(session, GNUTLS_SERVER);
490
480
if(ret != GNUTLS_E_SUCCESS){
491
481
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
492
482
safer_gnutls_strerror(ret));
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);
487
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
504
488
if(ret != GNUTLS_E_SUCCESS){
505
489
fprintf(stderr, "Syntax error at: %s\n", err);
506
490
fprintf(stderr, "GnuTLS error: %s\n",
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
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
521
499
if(ret != GNUTLS_E_SUCCESS){
522
500
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
523
501
safer_gnutls_strerror(ret));
541
520
static int start_mandos_communication(const char *ip, uint16_t port,
542
521
AvahiIfIndex if_index,
544
int ret, tcp_sd = -1;
547
526
struct sockaddr_in in;
548
527
struct sockaddr_in6 in6;
550
529
char *buffer = NULL;
551
char *decrypted_buffer = NULL;
530
char *decrypted_buffer;
552
531
size_t buffer_length = 0;
553
532
size_t buffer_capacity = 0;
533
ssize_t decrypted_buffer_size;
556
536
gnutls_session_t session;
557
537
int pf; /* Protocol family */
737
672
fprintf(stderr, "Establishing TLS session with %s\n", ip);
745
/* Spurious warnings from -Wint-to-pointer-cast */
746
675
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
754
678
ret = gnutls_handshake(session);
759
679
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
761
681
if(ret != GNUTLS_E_SUCCESS){
806
714
case GNUTLS_E_AGAIN:
808
716
case GNUTLS_E_REHANDSHAKE:
810
718
ret = gnutls_handshake(session);
816
719
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
818
721
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
819
722
gnutls_perror(ret);
825
728
fprintf(stderr, "Unknown error while reading data from"
826
729
" encrypted session with Mandos server\n");
827
731
gnutls_bye(session, GNUTLS_SHUT_RDWR);
837
740
fprintf(stderr, "Closing TLS session\n");
846
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
851
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
743
gnutls_bye(session, GNUTLS_SHUT_RDWR);
853
745
if(buffer_length > 0){
854
ssize_t decrypted_buffer_size;
855
746
decrypted_buffer_size = pgp_packet_decrypt(buffer,
857
748
&decrypted_buffer);
858
749
if(decrypted_buffer_size >= 0){
861
751
while(written < (size_t) decrypted_buffer_size){
867
752
ret = (int)fwrite(decrypted_buffer + written, 1,
868
753
(size_t)decrypted_buffer_size - written,
870
755
if(ret == 0 and ferror(stdout)){
873
757
fprintf(stderr, "Error writing encrypted data: %s\n",
874
758
strerror(errno));
879
763
written += (size_t)ret;
765
free(decrypted_buffer);
885
773
/* Shutdown procedure */
890
free(decrypted_buffer);
893
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
901
gnutls_deinit(session);
777
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
781
gnutls_deinit(session);
1025
892
errno = old_errno;
1029
* This function determines if a directory entry in /sys/class/net
1030
* corresponds to an acceptable network device.
1031
* (This function is passed to scandir(3) as a filter function.)
1033
int good_interface(const struct dirent *if_entry){
1035
char *flagname = NULL;
1036
if(if_entry->d_name[0] == '.'){
1039
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1045
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1052
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1053
/* read line from flags_fd */
1054
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1055
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1056
flagstring[(size_t)to_read] = '\0';
1057
if(flagstring == NULL){
1063
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1080
tmpmax = strtoimax(flagstring, &tmp, 0);
1081
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1082
and not (isspace(*tmp)))
1083
or tmpmax != (ifreq_flags)tmpmax){
1085
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1086
flagstring, if_entry->d_name);
1092
ifreq_flags flags = (ifreq_flags)tmpmax;
1093
/* Reject the loopback device */
1094
if(flags & IFF_LOOPBACK){
1096
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1101
/* Accept point-to-point devices only if connect_to is specified */
1102
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1104
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1109
/* Otherwise, reject non-broadcast-capable devices */
1110
if(not (flags & IFF_BROADCAST)){
1112
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1117
/* Reject non-ARP interfaces (including dummy interfaces) */
1118
if(flags & IFF_NOARP){
1120
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1125
/* Accept this device */
1127
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1133
int notdotentries(const struct dirent *direntry){
1134
/* Skip "." and ".." */
1135
if(direntry->d_name[0] == '.'
1136
and (direntry->d_name[1] == '\0'
1137
or (direntry->d_name[1] == '.'
1138
and direntry->d_name[2] == '\0'))){
1144
895
int main(int argc, char *argv[]){
1145
896
AvahiSServiceBrowser *sb = NULL;
1148
899
intmax_t tmpmax;
1150
901
int exitcode = EXIT_SUCCESS;
1151
const char *interface = "";
902
const char *interface = "eth0";
1152
903
struct ifreq network;
1154
bool take_down_interface = false;
907
char *connect_to = NULL;
1157
908
char tempdir[] = "/tmp/mandosXXXXXX";
1158
909
bool tempdir_created = false;
1159
910
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1164
915
bool gpgme_initialized = false;
1165
916
float delay = 2.5f;
1167
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
918
struct sigaction old_sigterm_action;
1168
919
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1173
/* Lower any group privileges we might have, just to be safe */
1180
/* Lower user privileges (temporarily) */
1192
922
struct argp_option options[] = {
1193
923
{ .name = "debug", .key = 128,
1222
952
.arg = "SECONDS",
1223
953
.doc = "Maximum delay to wait for interface startup",
1226
* These reproduce what we would get without ARGP_NO_HELP
1228
{ .name = "help", .key = '?',
1229
.doc = "Give this help list", .group = -1 },
1230
{ .name = "usage", .key = -3,
1231
.doc = "Give a short usage message", .group = -1 },
1232
{ .name = "version", .key = 'V',
1233
.doc = "Print program version", .group = -1 },
1234
955
{ .name = NULL }
1237
958
error_t parse_opt(int key, char *arg,
1238
959
struct argp_state *state){
1241
961
case 128: /* --debug */
1258
978
tmpmax = strtoimax(arg, &tmp, 10);
1259
979
if(errno != 0 or tmp == arg or *tmp != '\0'
1260
980
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1261
argp_error(state, "Bad number of DH bits");
981
fprintf(stderr, "Bad number of DH bits\n");
1263
984
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1270
991
delay = strtof(arg, &tmp);
1271
992
if(errno != 0 or tmp == arg or *tmp != '\0'){
1272
argp_error(state, "Bad delay");
993
fprintf(stderr, "Bad delay\n");
1276
* These reproduce what we would get without ARGP_NO_HELP
1278
case '?': /* --help */
1279
argp_state_help(state, state->out_stream,
1280
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1281
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1282
case -3: /* --usage */
1283
argp_state_help(state, state->out_stream,
1284
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1285
case 'V': /* --version */
1286
fprintf(state->out_stream, "%s\n", argp_program_version);
1287
exit(argp_err_exit_status);
1290
1002
return ARGP_ERR_UNKNOWN;
1295
1007
struct argp argp = { .options = options, .parser = parse_opt,
1296
1008
.args_doc = "",
1297
1009
.doc = "Mandos client -- Get and decrypt"
1298
1010
" passwords from a Mandos server" };
1299
ret = argp_parse(&argp, argc, argv,
1300
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1307
perror("argp_parse");
1308
exitcode = EX_OSERR;
1311
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;
1317
1020
avahi_set_log_function(empty_log);
1320
if(interface[0] == '\0'){
1321
struct dirent **direntries;
1322
ret = scandir(sys_class_net, &direntries, good_interface,
1325
/* Pick the first good interface */
1326
interface = strdup(direntries[0]->d_name);
1328
fprintf(stderr, "Using interface \"%s\"\n", interface);
1330
if(interface == NULL){
1333
exitcode = EXIT_FAILURE;
1339
fprintf(stderr, "Could not find a network interface\n");
1340
exitcode = EXIT_FAILURE;
1345
1023
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1346
1024
from the signal handler */
1357
1035
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1359
1037
perror("sigaddset");
1360
exitcode = EX_OSERR;
1038
exitcode = EXIT_FAILURE;
1363
1041
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1365
1043
perror("sigaddset");
1366
exitcode = EX_OSERR;
1044
exitcode = EXIT_FAILURE;
1369
1047
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1371
1049
perror("sigaddset");
1372
exitcode = EX_OSERR;
1375
/* Need to check if the handler is SIG_IGN before handling:
1376
| [[info:libc:Initial Signal Actions]] |
1377
| [[info:libc:Basic Signal Handling]] |
1379
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1381
perror("sigaction");
1384
if(old_sigterm_action.sa_handler != SIG_IGN){
1385
ret = sigaction(SIGINT, &sigterm_action, NULL);
1387
perror("sigaction");
1388
exitcode = EX_OSERR;
1392
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1394
perror("sigaction");
1397
if(old_sigterm_action.sa_handler != SIG_IGN){
1398
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1400
perror("sigaction");
1401
exitcode = EX_OSERR;
1405
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1407
perror("sigaction");
1410
if(old_sigterm_action.sa_handler != SIG_IGN){
1411
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1413
perror("sigaction");
1414
exitcode = EX_OSERR;
1050
exitcode = EXIT_FAILURE;
1053
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1055
perror("sigaction");
1056
exitcode = EXIT_FAILURE;
1419
1060
/* If the interface is down, bring it up */
1420
if(strcmp(interface, "none") != 0){
1421
if_index = (AvahiIfIndex) if_nametoindex(interface);
1423
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1424
exitcode = EX_UNAVAILABLE;
1432
/* Re-raise priviliges */
1061
if(interface[0] != '\0'){
1439
1062
#ifdef __linux__
1440
1063
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1441
messages about the network interface to mess up the prompt */
1064
messages to mess up the prompt */
1442
1065
ret = klogctl(8, NULL, 5);
1443
1066
bool restore_loglevel = true;
1481
1098
#endif /* __linux__ */
1482
exitcode = EX_OSERR;
1483
/* Lower privileges */
1099
exitcode = EXIT_FAILURE;
1491
1102
if((network.ifr_flags & IFF_UP) == 0){
1492
1103
network.ifr_flags |= IFF_UP;
1493
take_down_interface = true;
1494
1104
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1496
take_down_interface = false;
1497
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1498
exitcode = EX_OSERR;
1106
perror("ioctl SIOCSIFFLAGS");
1107
exitcode = EXIT_FAILURE;
1499
1108
#ifdef __linux__
1500
1109
if(restore_loglevel){
1501
1110
ret = klogctl(7, NULL, 0);
1545
1145
#endif /* __linux__ */
1546
/* Lower privileges */
1548
if(take_down_interface){
1549
/* Lower privileges */
1555
/* Lower privileges permanently */
1567
1162
ret = init_gnutls_global(pubkey, seckey);
1569
1164
fprintf(stderr, "init_gnutls_global failed\n");
1570
exitcode = EX_UNAVAILABLE;
1165
exitcode = EXIT_FAILURE;
1573
1168
gnutls_initialized = true;
1580
1171
if(mkdtemp(tempdir) == NULL){
1581
1172
perror("mkdtemp");
1584
1175
tempdir_created = true;
1590
1177
if(not init_gpgme(pubkey, seckey, tempdir)){
1591
1178
fprintf(stderr, "init_gpgme failed\n");
1592
exitcode = EX_UNAVAILABLE;
1179
exitcode = EXIT_FAILURE;
1595
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;
1602
1194
if(connect_to != NULL){
1605
1197
char *address = strrchr(connect_to, ':');
1606
1198
if(address == NULL){
1607
1199
fprintf(stderr, "No colon in address\n");
1608
exitcode = EX_USAGE;
1200
exitcode = EXIT_FAILURE;
1618
1205
tmpmax = strtoimax(address+1, &tmp, 10);
1619
1206
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1620
1207
or tmpmax != (uint16_t)tmpmax){
1621
1208
fprintf(stderr, "Bad port number\n");
1622
exitcode = EX_USAGE;
1209
exitcode = EXIT_FAILURE;
1630
1212
port = (uint16_t)tmpmax;
1631
1213
*address = '\0';
1632
1214
address = connect_to;
1645
while(not quit_now){
1646
ret = start_mandos_communication(address, port, if_index, af);
1647
if(quit_now or ret == 0){
1222
ret = start_mandos_communication(address, port, if_index, af);
1224
exitcode = EXIT_FAILURE;
1654
1226
exitcode = EXIT_SUCCESS;
1665
1232
AvahiServerConfig config;
1666
1233
/* Do not publish any local Zeroconf records */
1740
1299
gpgme_release(mc.ctx);
1743
/* Take down the network interface */
1744
if(take_down_interface){
1745
/* Re-raise priviliges */
1752
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1754
perror("ioctl SIOCGIFFLAGS");
1755
} else if(network.ifr_flags & IFF_UP) {
1756
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1757
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1759
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1762
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1766
/* Lower privileges permanently */
1775
/* Removes the GPGME temp directory and all files inside */
1302
/* Removes the temp directory used by GPGME */
1776
1303
if(tempdir_created){
1777
struct dirent **direntries = NULL;
1778
struct dirent *direntry = NULL;
1779
ret = scandir(tempdir, &direntries, notdotentries, alphasort);
1781
for(int i = 0; i < ret; i++){
1782
direntry = direntries[i];
1305
struct dirent *direntry;
1306
d = opendir(tempdir);
1308
if(errno != ENOENT){
1313
direntry = readdir(d);
1314
if(direntry == NULL){
1317
/* Skip "." and ".." */
1318
if(direntry->d_name[0] == '.'
1319
and (direntry->d_name[1] == '\0'
1320
or (direntry->d_name[1] == '.'
1321
and direntry->d_name[2] == '\0'))){
1783
1324
char *fullname = NULL;
1784
1325
ret = asprintf(&fullname, "%s/%s", tempdir,
1785
1326
direntry->d_name);