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() */
65
61
#include <errno.h> /* perror(), errno */
66
62
#include <time.h> /* nanosleep(), time() */
71
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
70
getuid(), getgid(), setuid(),
76
72
#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
79
75
argp_state, struct argp,
80
76
argp_parse(), ARGP_KEY_ARG,
81
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
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 */
78
#include <signal.h> /* sigemptyset(), sigaddset(), sigaction(), SIGTERM, sigaction */
89
80
#include <sys/klog.h> /* klogctl() */
90
#endif /* __linux__ */
93
84
/* All Avahi types, constants and functions
144
135
.dh_bits = 1024, .priority = "SECURE256"
145
136
":!CTYPE-X.509:+CTYPE-OPENPGP" };
147
sig_atomic_t quit_now = 0;
148
int signal_received = 0;
151
* Make additional room in "buffer" for at least BUFFER_SIZE more
152
* bytes. "buffer_capacity" is how much is currently allocated,
153
* "buffer_length" is how much is already used.
139
* Make additional room in "buffer" for at least BUFFER_SIZE
140
* additional bytes. "buffer_capacity" is how much is currently
141
* allocated, "buffer_length" is how much is already used.
155
143
size_t incbuffer(char **buffer, size_t buffer_length,
156
144
size_t buffer_capacity){
315
303
gpgme_recipient_t recipient;
316
304
recipient = result->recipients;
317
while(recipient != NULL){
318
fprintf(stderr, "Public key algorithm: %s\n",
319
gpgme_pubkey_algo_name(recipient->pubkey_algo));
320
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
321
fprintf(stderr, "Secret key available: %s\n",
322
recipient->status == GPG_ERR_NO_SECKEY
324
recipient = recipient->next;
306
while(recipient != NULL){
307
fprintf(stderr, "Public key algorithm: %s\n",
308
gpgme_pubkey_algo_name(recipient->pubkey_algo));
309
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
310
fprintf(stderr, "Secret key available: %s\n",
311
recipient->status == GPG_ERR_NO_SECKEY
313
recipient = recipient->next;
479
469
static int init_gnutls_session(gnutls_session_t *session){
481
471
/* GnuTLS session creation */
483
ret = gnutls_init(session, GNUTLS_SERVER);
487
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
472
ret = gnutls_init(session, GNUTLS_SERVER);
488
473
if(ret != GNUTLS_E_SUCCESS){
489
474
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
490
475
safer_gnutls_strerror(ret));
496
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
498
gnutls_deinit(*session);
501
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
480
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
502
481
if(ret != GNUTLS_E_SUCCESS){
503
482
fprintf(stderr, "Syntax error at: %s\n", err);
504
483
fprintf(stderr, "GnuTLS error: %s\n",
512
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
515
gnutls_deinit(*session);
518
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
490
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
519
492
if(ret != GNUTLS_E_SUCCESS){
520
493
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
521
494
safer_gnutls_strerror(ret));
539
513
static int start_mandos_communication(const char *ip, uint16_t port,
540
514
AvahiIfIndex if_index,
542
int ret, tcp_sd = -1;
545
519
struct sockaddr_in in;
546
520
struct sockaddr_in6 in6;
548
522
char *buffer = NULL;
549
char *decrypted_buffer = NULL;
523
char *decrypted_buffer;
550
524
size_t buffer_length = 0;
551
525
size_t buffer_capacity = 0;
526
ssize_t decrypted_buffer_size;
554
529
gnutls_session_t session;
555
530
int pf; /* Protocol family */
587
554
tcp_sd = socket(pf, SOCK_STREAM, 0);
590
556
perror("socket");
600
560
memset(&to, 0, sizeof(to));
601
561
if(af == AF_INET6){
602
to.in6.sin6_family = (sa_family_t)af;
562
to.in6.sin6_family = (uint16_t)af;
603
563
ret = inet_pton(af, ip, &to.in6.sin6_addr);
604
564
} else { /* IPv4 */
605
565
to.in.sin_family = (sa_family_t)af;
606
566
ret = inet_pton(af, ip, &to.in.sin_addr);
610
569
perror("inet_pton");
616
573
fprintf(stderr, "Bad address: %s\n", ip);
620
576
if(af == AF_INET6){
621
577
to.in6.sin6_port = htons(port); /* Spurious warnings from
733
665
fprintf(stderr, "Establishing TLS session with %s\n", ip);
741
668
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
749
671
ret = gnutls_handshake(session);
754
672
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
756
674
if(ret != GNUTLS_E_SUCCESS){
801
707
case GNUTLS_E_AGAIN:
803
709
case GNUTLS_E_REHANDSHAKE:
805
711
ret = gnutls_handshake(session);
811
712
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
813
714
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
814
715
gnutls_perror(ret);
820
721
fprintf(stderr, "Unknown error while reading data from"
821
722
" encrypted session with Mandos server\n");
822
724
gnutls_bye(session, GNUTLS_SHUT_RDWR);
832
733
fprintf(stderr, "Closing TLS session\n");
841
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
846
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
736
gnutls_bye(session, GNUTLS_SHUT_RDWR);
848
738
if(buffer_length > 0){
849
ssize_t decrypted_buffer_size;
850
739
decrypted_buffer_size = pgp_packet_decrypt(buffer,
852
741
&decrypted_buffer);
853
742
if(decrypted_buffer_size >= 0){
856
744
while(written < (size_t) decrypted_buffer_size){
862
745
ret = (int)fwrite(decrypted_buffer + written, 1,
863
746
(size_t)decrypted_buffer_size - written,
865
748
if(ret == 0 and ferror(stdout)){
868
750
fprintf(stderr, "Error writing encrypted data: %s\n",
869
751
strerror(errno));
874
756
written += (size_t)ret;
758
free(decrypted_buffer);
880
766
/* Shutdown procedure */
885
free(decrypted_buffer);
888
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
896
gnutls_deinit(session);
770
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
774
gnutls_deinit(session);
916
788
AVAHI_GCC_UNUSED AvahiStringList *txt,
917
789
AVAHI_GCC_UNUSED AvahiLookupResultFlags
919
AVAHI_GCC_UNUSED void* userdata){
791
__attribute__((unused)) void* userdata){
922
794
/* Called whenever a service has been resolved successfully or
931
799
case AVAHI_RESOLVER_FAILURE:
987
851
the callback function is called the Avahi server will free the
988
852
resolver for us. */
990
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
991
name, type, domain, protocol, 0,
992
resolve_callback, NULL) == NULL)
854
if(!(avahi_s_service_resolver_new(mc.server, interface,
855
protocol, name, type, domain,
856
AVAHI_PROTO_INET6, 0,
857
resolve_callback, NULL)))
993
858
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
994
859
name, avahi_strerror(avahi_server_errno(mc.server)));
1009
874
/* stop main loop after sigterm has been called */
1010
static void handle_sigterm(int sig){
1015
signal_received = sig;
875
static void handle_sigterm(__attribute__((unused)) int sig){
1016
876
int old_errno = errno;
1017
if(mc.simple_poll != NULL){
1018
avahi_simple_poll_quit(mc.simple_poll);
877
avahi_simple_poll_quit(mc.simple_poll);
1020
878
errno = old_errno;
1043
900
bool gnutls_initialized = false;
1044
901
bool gpgme_initialized = false;
1047
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
904
struct sigaction old_sigterm_action;
1048
905
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1053
/* Lower any group privileges we might have, just to be safe */
1060
/* Lower user privileges (temporarily) */
1072
908
struct argp_option options[] = {
1073
909
{ .name = "debug", .key = 128,
1102
938
.arg = "SECONDS",
1103
939
.doc = "Maximum delay to wait for interface startup",
1106
* These reproduce what we would get without ARGP_NO_HELP
1108
{ .name = "help", .key = '?',
1109
.doc = "Give this help list", .group = -1 },
1110
{ .name = "usage", .key = -3,
1111
.doc = "Give a short usage message", .group = -1 },
1112
{ .name = "version", .key = 'V',
1113
.doc = "Print program version", .group = -1 },
1114
941
{ .name = NULL }
1117
944
error_t parse_opt(int key, char *arg,
1118
945
struct argp_state *state){
1121
947
case 128: /* --debug */
1136
962
case 129: /* --dh-bits */
1138
tmpmax = strtoimax(arg, &tmp, 10);
1139
if(errno != 0 or tmp == arg or *tmp != '\0'
1140
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1141
argp_error(state, "Bad number of DH bits");
963
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
964
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
965
or arg[numchars] != '\0'){
966
fprintf(stderr, "Bad number of DH bits\n");
1143
969
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1146
972
mc.priority = arg;
1148
974
case 131: /* --delay */
1150
delay = strtof(arg, &tmp);
1151
if(errno != 0 or tmp == arg or *tmp != '\0'){
1152
argp_error(state, "Bad delay");
975
ret = sscanf(arg, "%lf%n", &delay, &numchars);
976
if(ret < 1 or arg[numchars] != '\0'){
977
fprintf(stderr, "Bad delay\n");
1156
* These reproduce what we would get without ARGP_NO_HELP
1158
case '?': /* --help */
1159
argp_state_help(state, state->out_stream,
1160
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1161
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1162
case -3: /* --usage */
1163
argp_state_help(state, state->out_stream,
1164
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1165
case 'V': /* --version */
1166
fprintf(state->out_stream, "%s\n", argp_program_version);
1167
exit(argp_err_exit_status);
1170
986
return ARGP_ERR_UNKNOWN;
1175
991
struct argp argp = { .options = options, .parser = parse_opt,
1177
993
.doc = "Mandos client -- Get and decrypt"
1178
994
" passwords from a Mandos server" };
1179
ret = argp_parse(&argp, argc, argv,
1180
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1187
perror("argp_parse");
1188
exitcode = EX_OSERR;
1191
exitcode = EX_USAGE;
995
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
996
if(ret == ARGP_ERR_UNKNOWN){
997
fprintf(stderr, "Unknown error while parsing arguments\n");
998
exitcode = EXIT_FAILURE;
1197
1004
avahi_set_log_function(empty_log);
1200
1007
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1201
1008
from the signal handler */
1202
1009
/* Initialize the pseudo-RNG for Avahi */
1204
1011
mc.simple_poll = avahi_simple_poll_new();
1205
1012
if(mc.simple_poll == NULL){
1206
1013
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1207
exitcode = EX_UNAVAILABLE;
1014
exitcode = EXIT_FAILURE;
1211
1018
sigemptyset(&sigterm_action.sa_mask);
1212
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1214
perror("sigaddset");
1215
exitcode = EX_OSERR;
1218
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1220
perror("sigaddset");
1221
exitcode = EX_OSERR;
1224
1019
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1226
1021
perror("sigaddset");
1227
exitcode = EX_OSERR;
1230
/* Need to check if the handler is SIG_IGN before handling:
1231
| [[info:libc:Initial Signal Actions]] |
1232
| [[info:libc:Basic Signal Handling]] |
1234
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1236
perror("sigaction");
1239
if(old_sigterm_action.sa_handler != SIG_IGN){
1240
ret = sigaction(SIGINT, &sigterm_action, NULL);
1242
perror("sigaction");
1243
exitcode = EX_OSERR;
1247
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1249
perror("sigaction");
1252
if(old_sigterm_action.sa_handler != SIG_IGN){
1253
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1255
perror("sigaction");
1256
exitcode = EX_OSERR;
1260
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1262
perror("sigaction");
1265
if(old_sigterm_action.sa_handler != SIG_IGN){
1266
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1268
perror("sigaction");
1269
exitcode = EX_OSERR;
1022
exitcode = EXIT_FAILURE;
1025
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1027
perror("sigaction");
1028
exitcode = EXIT_FAILURE;
1274
1033
/* If the interface is down, bring it up */
1275
1034
if(interface[0] != '\0'){
1276
if_index = (AvahiIfIndex) if_nametoindex(interface);
1278
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1279
exitcode = EX_UNAVAILABLE;
1287
/* Re-raise priviliges */
1294
1035
#ifdef __linux__
1295
1036
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1296
messages about the network interface to mess up the prompt */
1037
messages to mess up the prompt */
1297
1038
ret = klogctl(8, NULL, 5);
1298
1039
bool restore_loglevel = true;
1300
1041
restore_loglevel = false;
1301
1042
perror("klogctl");
1303
#endif /* __linux__ */
1305
1046
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1307
1048
perror("socket");
1308
exitcode = EX_OSERR;
1049
exitcode = EXIT_FAILURE;
1309
1050
#ifdef __linux__
1310
1051
if(restore_loglevel){
1311
1052
ret = klogctl(7, NULL, 0);
1333
1068
perror("klogctl");
1336
#endif /* __linux__ */
1337
exitcode = EX_OSERR;
1338
/* Lower privileges */
1072
exitcode = EXIT_FAILURE;
1346
1075
if((network.ifr_flags & IFF_UP) == 0){
1347
1076
network.ifr_flags |= IFF_UP;
1348
take_down_interface = true;
1349
1077
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1351
take_down_interface = false;
1352
1079
perror("ioctl SIOCSIFFLAGS");
1353
exitcode = EX_OSERR;
1080
exitcode = EXIT_FAILURE;
1354
1081
#ifdef __linux__
1355
1082
if(restore_loglevel){
1356
1083
ret = klogctl(7, NULL, 0);
1397
1115
perror("klogctl");
1400
#endif /* __linux__ */
1401
/* Lower privileges */
1403
if(take_down_interface){
1404
/* Lower privileges */
1410
/* Lower privileges permanently */
1422
1135
ret = init_gnutls_global(pubkey, seckey);
1424
1137
fprintf(stderr, "init_gnutls_global failed\n");
1425
exitcode = EX_UNAVAILABLE;
1138
exitcode = EXIT_FAILURE;
1428
1141
gnutls_initialized = true;
1435
tempdir_created = true;
1436
1144
if(mkdtemp(tempdir) == NULL){
1437
tempdir_created = false;
1438
1145
perror("mkdtemp");
1148
tempdir_created = true;
1446
1150
if(not init_gpgme(pubkey, seckey, tempdir)){
1447
1151
fprintf(stderr, "init_gpgme failed\n");
1448
exitcode = EX_UNAVAILABLE;
1152
exitcode = EXIT_FAILURE;
1451
1155
gpgme_initialized = true;
1158
if(interface[0] != '\0'){
1159
if_index = (AvahiIfIndex) if_nametoindex(interface);
1161
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1162
exitcode = EXIT_FAILURE;
1458
1167
if(connect_to != NULL){
1461
1170
char *address = strrchr(connect_to, ':');
1462
1171
if(address == NULL){
1463
1172
fprintf(stderr, "No colon in address\n");
1464
exitcode = EX_USAGE;
1173
exitcode = EXIT_FAILURE;
1474
tmpmax = strtoimax(address+1, &tmp, 10);
1475
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1476
or tmpmax != (uint16_t)tmpmax){
1177
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1178
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1179
or address[numchars+1] != '\0'){
1477
1180
fprintf(stderr, "Bad port number\n");
1478
exitcode = EX_USAGE;
1181
exitcode = EXIT_FAILURE;
1486
1184
port = (uint16_t)tmpmax;
1487
1185
*address = '\0';
1488
1186
address = connect_to;
1501
ret = start_mandos_communication(address, port, if_index, af);
1194
ret = start_mandos_communication(address, port, if_index,
1507
exitcode = EX_NOHOST;
1510
exitcode = EX_USAGE;
1513
exitcode = EX_IOERR;
1516
exitcode = EX_PROTOCOL;
1519
exitcode = EX_OSERR;
1197
exitcode = EXIT_FAILURE;
1523
1199
exitcode = EXIT_SUCCESS;
1533
1205
AvahiServerConfig config;
1534
1206
/* Do not publish any local Zeroconf records */
1551
1223
if(mc.server == NULL){
1552
1224
fprintf(stderr, "Failed to create Avahi server: %s\n",
1553
1225
avahi_strerror(error));
1554
exitcode = EX_UNAVAILABLE;
1226
exitcode = EXIT_FAILURE;
1562
1230
/* Create the Avahi service browser */
1563
1231
sb = avahi_s_service_browser_new(mc.server, if_index,
1564
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1232
AVAHI_PROTO_INET6, "_mandos._tcp",
1565
1233
NULL, 0, browse_callback, NULL);
1566
1234
if(sb == NULL){
1567
1235
fprintf(stderr, "Failed to create service browser: %s\n",
1568
1236
avahi_strerror(avahi_server_errno(mc.server)));
1569
exitcode = EX_UNAVAILABLE;
1237
exitcode = EXIT_FAILURE;
1608
1272
gpgme_release(mc.ctx);
1611
/* Take down the network interface */
1612
if(take_down_interface){
1613
/* Re-raise priviliges */
1620
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1622
perror("ioctl SIOCGIFFLAGS");
1623
} else if(network.ifr_flags & IFF_UP) {
1624
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1625
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1627
perror("ioctl SIOCSIFFLAGS");
1630
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1634
/* Lower privileges permanently */
1643
1275
/* Removes the temp directory used by GPGME */
1644
1276
if(tempdir_created){
1688
sigemptyset(&old_sigterm_action.sa_mask);
1689
old_sigterm_action.sa_handler = SIG_DFL;
1690
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1691
&old_sigterm_action,
1694
perror("sigaction");
1697
ret = raise(signal_received);
1698
} while(ret != 0 and errno == EINTR);
1703
TEMP_FAILURE_RETRY(pause());
1706
1319
return exitcode;