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() */
42
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
39
stdout, ferror(), sscanf(),
44
41
#include <stdint.h> /* uint16_t, uint32_t */
45
42
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
48
45
#include <stdbool.h> /* bool, false, true */
49
46
#include <string.h> /* memset(), strcmp(), strlen(),
50
47
strerror(), asprintf(), strcpy() */
59
56
#include <fcntl.h> /* open() */
60
57
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
59
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
64
60
#include <assert.h> /* assert() */
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61
#include <errno.h> /* perror(), errno */
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#include <time.h> /* nanosleep(), time(), sleep() */
62
#include <time.h> /* nanosleep(), time() */
67
63
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
64
SIOCSIFFLAGS, if_indextoname(),
69
65
if_nametoindex(), IF_NAMESIZE */
71
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INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
70
getuid(), getgid(), setuid(),
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#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
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argp_parse(), ARGP_KEY_ARG,
81
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
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#include <signal.h> /* sigemptyset(), sigaddset(),
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sigaction(), SIGTERM, sig_atomic_t,
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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
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EX_NOHOST, EX_IOERR, EX_PROTOCOL */
79
sigaction(), SIGTERM, sigaction,
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#include <sys/klog.h> /* klogctl() */
317
306
gpgme_recipient_t recipient;
318
307
recipient = result->recipients;
319
while(recipient != NULL){
320
fprintf(stderr, "Public key algorithm: %s\n",
321
gpgme_pubkey_algo_name(recipient->pubkey_algo));
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fprintf(stderr, "Key ID: %s\n", recipient->keyid);
323
fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
326
recipient = recipient->next;
309
while(recipient != NULL){
310
fprintf(stderr, "Public key algorithm: %s\n",
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gpgme_pubkey_algo_name(recipient->pubkey_algo));
312
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
313
fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
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recipient = recipient->next;
589
557
tcp_sd = socket(pf, SOCK_STREAM, 0);
592
559
perror("socket");
602
563
memset(&to, 0, sizeof(to));
603
564
if(af == AF_INET6){
604
to.in6.sin6_family = (sa_family_t)af;
565
to.in6.sin6_family = (uint16_t)af;
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566
ret = inet_pton(af, ip, &to.in6.sin6_addr);
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567
} else { /* IPv4 */
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568
to.in.sin_family = (sa_family_t)af;
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569
ret = inet_pton(af, ip, &to.in.sin_addr);
612
572
perror("inet_pton");
618
576
fprintf(stderr, "Bad address: %s\n", ip);
622
579
if(af == AF_INET6){
623
580
to.in6.sin6_port = htons(port); /* Spurious warnings from
836
736
fprintf(stderr, "Closing TLS session\n");
845
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
850
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
739
gnutls_bye(session, GNUTLS_SHUT_RDWR);
852
741
if(buffer_length > 0){
853
ssize_t decrypted_buffer_size;
854
742
decrypted_buffer_size = pgp_packet_decrypt(buffer,
856
744
&decrypted_buffer);
857
745
if(decrypted_buffer_size >= 0){
860
747
while(written < (size_t) decrypted_buffer_size){
866
748
ret = (int)fwrite(decrypted_buffer + written, 1,
867
749
(size_t)decrypted_buffer_size - written,
869
751
if(ret == 0 and ferror(stdout)){
872
753
fprintf(stderr, "Error writing encrypted data: %s\n",
873
754
strerror(errno));
878
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written += (size_t)ret;
761
free(decrypted_buffer);
884
769
/* Shutdown procedure */
889
free(decrypted_buffer);
892
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
900
gnutls_deinit(session);
773
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
777
gnutls_deinit(session);
991
854
the callback function is called the Avahi server will free the
992
855
resolver for us. */
994
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
995
name, type, domain, protocol, 0,
996
resolve_callback, NULL) == NULL)
857
if(!(avahi_s_service_resolver_new(mc.server, interface,
858
protocol, name, type, domain,
859
AVAHI_PROTO_INET6, 0,
860
resolve_callback, NULL)))
997
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fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
998
862
name, avahi_strerror(avahi_server_errno(mc.server)));
1024
889
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",
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/* 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",
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892
int main(int argc, char *argv[]){
1133
893
AvahiSServiceBrowser *sb = NULL;
1136
896
intmax_t tmpmax;
1138
898
int exitcode = EXIT_SUCCESS;
1139
const char *interface = "";
899
const char *interface = "eth0";
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900
struct ifreq network;
1142
bool take_down_interface = false;
904
char *connect_to = NULL;
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char tempdir[] = "/tmp/mandosXXXXXX";
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906
bool tempdir_created = false;
1147
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AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
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908
const char *seckey = PATHDIR "/" SECKEY;
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const char *pubkey = PATHDIR "/" PUBKEY;
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/* Initialize Mandos context */
912
mc = (mandos_context){ .simple_poll = NULL, .server = NULL,
913
.dh_bits = 1024, .priority = "SECURE256"
914
":!CTYPE-X.509:+CTYPE-OPENPGP" };
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915
bool gnutls_initialized = false;
1152
916
bool gpgme_initialized = false;
1155
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
919
struct sigaction old_sigterm_action;
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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) */
1180
923
struct argp_option options[] = {
1181
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{ .name = "debug", .key = 128,
1210
953
.arg = "SECONDS",
1211
954
.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 },
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{ .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 },
1222
956
{ .name = NULL }
1225
959
error_t parse_opt(int key, char *arg,
1226
960
struct argp_state *state){
1229
962
case 128: /* --debug */
1244
977
case 129: /* --dh-bits */
1246
tmpmax = strtoimax(arg, &tmp, 10);
1247
if(errno != 0 or tmp == arg or *tmp != '\0'
1248
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1249
argp_error(state, "Bad number of DH bits");
978
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
979
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
980
or arg[numchars] != '\0'){
981
fprintf(stderr, "Bad number of DH bits\n");
1251
984
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1254
987
mc.priority = arg;
1256
989
case 131: /* --delay */
1258
delay = strtof(arg, &tmp);
1259
if(errno != 0 or tmp == arg or *tmp != '\0'){
1260
argp_error(state, "Bad delay");
990
ret = sscanf(arg, "%lf%n", &delay, &numchars);
991
if(ret < 1 or arg[numchars] != '\0'){
992
fprintf(stderr, "Bad delay\n");
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);
1278
1001
return ARGP_ERR_UNKNOWN;
1283
1006
struct argp argp = { .options = options, .parser = parse_opt,
1284
1007
.args_doc = "",
1285
1008
.doc = "Mandos client -- Get and decrypt"
1286
1009
" passwords from a Mandos server" };
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;
1010
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1011
if(ret == ARGP_ERR_UNKNOWN){
1012
fprintf(stderr, "Unknown error while parsing arguments\n");
1013
exitcode = EXIT_FAILURE;
1305
1019
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;
1333
1022
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1334
1023
from the signal handler */
1345
1034
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1347
1036
perror("sigaddset");
1348
exitcode = EX_OSERR;
1037
exitcode = EXIT_FAILURE;
1351
1040
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1353
1042
perror("sigaddset");
1354
exitcode = EX_OSERR;
1043
exitcode = EXIT_FAILURE;
1357
1046
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1359
1048
perror("sigaddset");
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;
1049
exitcode = EXIT_FAILURE;
1052
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1054
perror("sigaction");
1055
exitcode = EXIT_FAILURE;
1407
1059
/* If the interface is down, bring it up */
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
if(interface[0] != '\0'){
1427
1061
#ifdef __linux__
1428
1062
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1429
messages about the network interface to mess up the prompt */
1063
messages to mess up the prompt */
1430
1064
ret = klogctl(8, NULL, 5);
1431
1065
bool restore_loglevel = true;
1533
1144
#endif /* __linux__ */
1534
/* Lower privileges */
1536
if(take_down_interface){
1537
/* Lower privileges */
1543
/* Lower privileges permanently */
1555
1161
ret = init_gnutls_global(pubkey, seckey);
1557
1163
fprintf(stderr, "init_gnutls_global failed\n");
1558
exitcode = EX_UNAVAILABLE;
1164
exitcode = EXIT_FAILURE;
1561
1167
gnutls_initialized = true;
1568
tempdir_created = true;
1569
1170
if(mkdtemp(tempdir) == NULL){
1570
tempdir_created = false;
1571
1171
perror("mkdtemp");
1174
tempdir_created = true;
1579
1176
if(not init_gpgme(pubkey, seckey, tempdir)){
1580
1177
fprintf(stderr, "init_gpgme failed\n");
1581
exitcode = EX_UNAVAILABLE;
1178
exitcode = EXIT_FAILURE;
1584
1181
gpgme_initialized = true;
1184
if(interface[0] != '\0'){
1185
if_index = (AvahiIfIndex) if_nametoindex(interface);
1187
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1188
exitcode = EXIT_FAILURE;
1591
1193
if(connect_to != NULL){
1594
1196
char *address = strrchr(connect_to, ':');
1595
1197
if(address == NULL){
1596
1198
fprintf(stderr, "No colon in address\n");
1597
exitcode = EX_USAGE;
1199
exitcode = EXIT_FAILURE;
1607
tmpmax = strtoimax(address+1, &tmp, 10);
1608
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1609
or tmpmax != (uint16_t)tmpmax){
1203
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1204
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1205
or address[numchars+1] != '\0'){
1610
1206
fprintf(stderr, "Bad port number\n");
1611
exitcode = EX_USAGE;
1207
exitcode = EXIT_FAILURE;
1619
1210
port = (uint16_t)tmpmax;
1620
1211
*address = '\0';
1621
1212
address = connect_to;
1672
1248
if(mc.server == NULL){
1673
1249
fprintf(stderr, "Failed to create Avahi server: %s\n",
1674
1250
avahi_strerror(error));
1675
exitcode = EX_UNAVAILABLE;
1251
exitcode = EXIT_FAILURE;
1683
1255
/* Create the Avahi service browser */
1684
1256
sb = avahi_s_service_browser_new(mc.server, if_index,
1685
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1257
AVAHI_PROTO_INET6, "_mandos._tcp",
1686
1258
NULL, 0, browse_callback, NULL);
1687
1259
if(sb == NULL){
1688
1260
fprintf(stderr, "Failed to create service browser: %s\n",
1689
1261
avahi_strerror(avahi_server_errno(mc.server)));
1690
exitcode = EX_UNAVAILABLE;
1262
exitcode = EXIT_FAILURE;
1729
1297
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 */
1764
1300
/* Removes the temp directory used by GPGME */
1765
1301
if(tempdir_created){