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 */
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49
#include <string.h> /* memset(), strcmp(), strlen(),
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strerror(), asprintf(), strcpy() */
73
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
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getuid(), getgid(), seteuid(),
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#include <arpa/inet.h> /* inet_pton(), htons */
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#include <iso646.h> /* not, or, and */
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78
#include <argp.h> /* struct argp_option, error_t, struct
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#include <signal.h> /* sigemptyset(), sigaddset(),
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sigaction(), SIGTERM, sig_atomic_t,
85
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
89
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#include <sys/klog.h> /* klogctl() */
127
125
static const char mandos_protocol_version[] = "1";
128
126
const char *argp_program_version = "mandos-client " VERSION;
129
127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
130
static const char sys_class_net[] = "/sys/class/net";
131
char *connect_to = NULL;
133
129
/* Used for passing in values through the Avahi callback functions */
146
142
.dh_bits = 1024, .priority = "SECURE256"
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":!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,
483
476
/* GnuTLS session creation */
485
478
ret = gnutls_init(session, GNUTLS_SERVER);
489
479
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
490
480
if(ret != GNUTLS_E_SUCCESS){
491
481
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
498
488
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
500
gnutls_deinit(*session);
503
489
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
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490
if(ret != GNUTLS_E_SUCCESS){
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491
fprintf(stderr, "Syntax error at: %s\n", err);
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500
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
517
gnutls_deinit(*session);
520
502
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
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if(ret != GNUTLS_E_SUCCESS){
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504
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
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519
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
538
520
__attribute__((unused)) const char *txt){}
522
sig_atomic_t quit_now = 0;
523
int signal_received = 0;
540
525
/* Called when a Mandos server is found */
541
526
static int start_mandos_communication(const char *ip, uint16_t port,
542
527
AvahiIfIndex if_index,
807
772
ret = gnutls_handshake(session);
813
777
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
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779
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
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780
gnutls_perror(ret);
822
786
fprintf(stderr, "Unknown error while reading data from"
823
787
" encrypted session with Mandos server\n");
824
789
gnutls_bye(session, GNUTLS_SHUT_RDWR);
843
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
848
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
805
gnutls_bye(session, GNUTLS_SHUT_RDWR);
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811
if(buffer_length > 0){
851
812
ssize_t decrypted_buffer_size;
865
825
(size_t)decrypted_buffer_size - written,
867
827
if(ret == 0 and ferror(stdout)){
870
829
fprintf(stderr, "Error writing encrypted data: %s\n",
871
830
strerror(errno));
876
835
written += (size_t)ret;
837
free(decrypted_buffer);
882
845
/* Shutdown procedure */
887
free(decrypted_buffer);
890
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
898
gnutls_deinit(session);
850
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
855
gnutls_deinit(session);
1022
976
errno = old_errno;
1026
* This function determines if a directory entry in /sys/class/net
1027
* corresponds to an acceptable network device.
1028
* (This function is passed to scandir(3) as a filter function.)
1030
int good_interface(const struct dirent *if_entry){
1032
char *flagname = NULL;
1033
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1039
if(if_entry->d_name[0] == '.'){
1042
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1047
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1048
/* read line from flags_fd */
1049
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1050
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1051
flagstring[(size_t)to_read] = '\0';
1052
if(flagstring == NULL){
1058
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1075
tmpmax = strtoimax(flagstring, &tmp, 0);
1076
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1077
and not (isspace(*tmp)))
1078
or tmpmax != (ifreq_flags)tmpmax){
1080
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1081
flagstring, if_entry->d_name);
1087
ifreq_flags flags = (ifreq_flags)tmpmax;
1088
/* Reject the loopback device */
1089
if(flags & IFF_LOOPBACK){
1091
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1096
/* Accept point-to-point devices only if connect_to is specified */
1097
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1099
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1104
/* Otherwise, reject non-broadcast-capable devices */
1105
if(not (flags & IFF_BROADCAST)){
1107
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1112
/* Accept this device */
1114
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1120
979
int main(int argc, char *argv[]){
1121
980
AvahiSServiceBrowser *sb = NULL;
1124
983
intmax_t tmpmax;
1126
985
int exitcode = EXIT_SUCCESS;
1127
const char *interface = "";
986
const char *interface = "eth0";
1128
987
struct ifreq network;
1130
989
bool take_down_interface = false;
992
char *connect_to = NULL;
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993
char tempdir[] = "/tmp/mandosXXXXXX";
1134
994
bool tempdir_created = false;
1135
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AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1198
1058
.arg = "SECONDS",
1199
1059
.doc = "Maximum delay to wait for interface startup",
1202
* These reproduce what we would get without ARGP_NO_HELP
1204
{ .name = "help", .key = '?',
1205
.doc = "Give this help list", .group = -1 },
1206
{ .name = "usage", .key = -3,
1207
.doc = "Give a short usage message", .group = -1 },
1208
{ .name = "version", .key = 'V',
1209
.doc = "Print program version", .group = -1 },
1210
1061
{ .name = NULL }
1213
1064
error_t parse_opt(int key, char *arg,
1214
1065
struct argp_state *state){
1217
1067
case 128: /* --debug */
1234
1084
tmpmax = strtoimax(arg, &tmp, 10);
1235
1085
if(errno != 0 or tmp == arg or *tmp != '\0'
1236
1086
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1237
argp_error(state, "Bad number of DH bits");
1087
fprintf(stderr, "Bad number of DH bits\n");
1239
1090
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1246
1097
delay = strtof(arg, &tmp);
1247
1098
if(errno != 0 or tmp == arg or *tmp != '\0'){
1248
argp_error(state, "Bad delay");
1099
fprintf(stderr, "Bad delay\n");
1252
* These reproduce what we would get without ARGP_NO_HELP
1254
case '?': /* --help */
1255
argp_state_help(state, state->out_stream,
1256
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1257
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1258
case -3: /* --usage */
1259
argp_state_help(state, state->out_stream,
1260
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1261
case 'V': /* --version */
1262
fprintf(state->out_stream, "%s\n", argp_program_version);
1263
exit(argp_err_exit_status);
1266
1108
return ARGP_ERR_UNKNOWN;
1271
1113
struct argp argp = { .options = options, .parser = parse_opt,
1272
1114
.args_doc = "",
1273
1115
.doc = "Mandos client -- Get and decrypt"
1274
1116
" passwords from a Mandos server" };
1275
ret = argp_parse(&argp, argc, argv,
1276
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1283
perror("argp_parse");
1284
exitcode = EX_OSERR;
1287
exitcode = EX_USAGE;
1117
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1118
if(ret == ARGP_ERR_UNKNOWN){
1119
fprintf(stderr, "Unknown error while parsing arguments\n");
1120
exitcode = EXIT_FAILURE;
1293
1126
avahi_set_log_function(empty_log);
1296
if(interface[0] == '\0'){
1297
struct dirent **direntries;
1298
ret = scandir(sys_class_net, &direntries, good_interface,
1301
/* Pick the first good interface */
1302
interface = strdup(direntries[0]->d_name);
1304
fprintf(stderr, "Using interface \"%s\"\n", interface);
1306
if(interface == NULL){
1309
exitcode = EXIT_FAILURE;
1315
fprintf(stderr, "Could not find a network interface\n");
1316
exitcode = EXIT_FAILURE;
1321
1129
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1322
1130
from the signal handler */
1333
1141
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1335
1143
perror("sigaddset");
1336
exitcode = EX_OSERR;
1144
exitcode = EXIT_FAILURE;
1339
1147
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1341
1149
perror("sigaddset");
1342
exitcode = EX_OSERR;
1150
exitcode = EXIT_FAILURE;
1345
1153
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1347
1155
perror("sigaddset");
1348
exitcode = EX_OSERR;
1156
exitcode = EXIT_FAILURE;
1351
1159
/* Need to check if the handler is SIG_IGN before handling:
1355
1163
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1357
1165
perror("sigaction");
1166
return EXIT_FAILURE;
1360
1168
if(old_sigterm_action.sa_handler != SIG_IGN){
1361
1169
ret = sigaction(SIGINT, &sigterm_action, NULL);
1363
1171
perror("sigaction");
1364
exitcode = EX_OSERR;
1172
exitcode = EXIT_FAILURE;
1368
1176
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1370
1178
perror("sigaction");
1179
return EXIT_FAILURE;
1373
1181
if(old_sigterm_action.sa_handler != SIG_IGN){
1374
1182
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1376
1184
perror("sigaction");
1377
exitcode = EX_OSERR;
1185
exitcode = EXIT_FAILURE;
1381
1189
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1383
1191
perror("sigaction");
1192
return EXIT_FAILURE;
1386
1194
if(old_sigterm_action.sa_handler != SIG_IGN){
1387
1195
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1389
1197
perror("sigaction");
1390
exitcode = EX_OSERR;
1198
exitcode = EXIT_FAILURE;
1395
1203
/* If the interface is down, bring it up */
1396
if(strcmp(interface, "none") != 0){
1204
if(interface[0] != '\0'){
1397
1205
if_index = (AvahiIfIndex) if_nametoindex(interface);
1398
1206
if(if_index == 0){
1399
1207
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1400
exitcode = EX_UNAVAILABLE;
1208
exitcode = EXIT_FAILURE;
1415
1223
#ifdef __linux__
1416
1224
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1417
messages about the network interface to mess up the prompt */
1225
messages to mess up the prompt */
1418
1226
ret = klogctl(8, NULL, 5);
1419
1227
bool restore_loglevel = true;
1470
1278
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1472
1280
take_down_interface = false;
1473
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1474
exitcode = EX_OSERR;
1281
perror("ioctl SIOCSIFFLAGS");
1282
exitcode = EXIT_FAILURE;
1475
1283
#ifdef __linux__
1476
1284
if(restore_loglevel){
1477
1285
ret = klogctl(7, NULL, 0);
1567
1375
if(not init_gpgme(pubkey, seckey, tempdir)){
1568
1376
fprintf(stderr, "init_gpgme failed\n");
1569
exitcode = EX_UNAVAILABLE;
1377
exitcode = EXIT_FAILURE;
1572
1380
gpgme_initialized = true;
1743
1533
perror("ioctl SIOCGIFFLAGS");
1744
1534
} else if(network.ifr_flags & IFF_UP) {
1745
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1535
network.ifr_flags &= ~IFF_UP; /* clear flag */
1746
1536
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1748
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1538
perror("ioctl SIOCSIFFLAGS");
1751
1541
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1809
1599
sigemptyset(&old_sigterm_action.sa_mask);
1810
1600
old_sigterm_action.sa_handler = SIG_DFL;
1811
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1812
&old_sigterm_action,
1601
ret = sigaction(signal_received, &old_sigterm_action, NULL);
1815
1603
perror("sigaction");
1818
ret = raise(signal_received);
1819
} while(ret != 0 and errno == EINTR);
1824
TEMP_FAILURE_RETRY(pause());
1605
raise(signal_received);
1827
1608
return exitcode;