43
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t */
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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,
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#include <stdbool.h> /* bool, false, true */
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#include <string.h> /* memset(), strcmp(), strlen(),
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strerror(), asprintf(), strcpy() */
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#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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#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,
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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
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#include <sys/klog.h> /* klogctl() */
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.dh_bits = 1024, .priority = "SECURE256"
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":!CTYPE-X.509:+CTYPE-OPENPGP" };
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sig_atomic_t quit_now = 0;
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int signal_received = 0;
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* Make additional room in "buffer" for at least BUFFER_SIZE more
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* bytes. "buffer_capacity" is how much is currently allocated,
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static int init_gnutls_session(gnutls_session_t *session){
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/* GnuTLS session creation */
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ret = gnutls_init(session, GNUTLS_SERVER);
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} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
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ret = gnutls_init(session, GNUTLS_SERVER);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
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safer_gnutls_strerror(ret));
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ret = gnutls_priority_set_direct(*session, mc.priority, &err);
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gnutls_deinit(*session);
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} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
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ret = gnutls_priority_set_direct(*session, mc.priority, &err);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Syntax error at: %s\n", err);
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fprintf(stderr, "GnuTLS error: %s\n",
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ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
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gnutls_deinit(*session);
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} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
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ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
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safer_gnutls_strerror(ret));
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504
/* ignore client certificate if any. */
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gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
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gnutls_certificate_server_set_request(*session,
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gnutls_dh_set_prime_bits(*session, mc.dh_bits);
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static void empty_log(__attribute__((unused)) AvahiLogLevel level,
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__attribute__((unused)) const char *txt){}
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sig_atomic_t quit_now = 0;
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int signal_received = 0;
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/* Called when a Mandos server is found */
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static int start_mandos_communication(const char *ip, uint16_t port,
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522
AvahiIfIndex if_index,
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struct sockaddr_in6 in6;
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char *buffer = NULL;
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char *decrypted_buffer = NULL;
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char *decrypted_buffer;
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532
size_t buffer_length = 0;
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size_t buffer_capacity = 0;
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gnutls_session_t session;
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int pf; /* Protocol family */
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if(if_index == AVAHI_IF_UNSPEC){
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fprintf(stderr, "An IPv6 link-local address is incomplete"
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" without a network interface\n");
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/* Set the network interface number as scope */
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ret = gnutls_handshake(session);
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} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
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fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
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gnutls_perror(ret);
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fprintf(stderr, "Unknown error while reading data from"
821
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" encrypted session with Mandos server\n");
822
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gnutls_bye(session, GNUTLS_SHUT_RDWR);
841
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
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} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
800
gnutls_bye(session, GNUTLS_SHUT_RDWR);
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if(buffer_length > 0){
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ssize_t decrypted_buffer_size;
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820
(size_t)decrypted_buffer_size - written,
865
822
if(ret == 0 and ferror(stdout)){
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fprintf(stderr, "Error writing encrypted data: %s\n",
869
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strerror(errno));
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written += (size_t)ret;
832
free(decrypted_buffer);
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/* Shutdown procedure */
885
free(decrypted_buffer);
888
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
896
gnutls_deinit(session);
845
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
850
gnutls_deinit(session);
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bool gpgme_initialized = false;
1045
996
float delay = 2.5f;
1047
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
998
struct sigaction old_sigterm_action;
1048
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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
1002
struct argp_option options[] = {
1073
1003
{ .name = "debug", .key = 128,
1102
1032
.arg = "SECONDS",
1103
1033
.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
1035
{ .name = NULL }
1117
1038
error_t parse_opt(int key, char *arg,
1118
1039
struct argp_state *state){
1121
1041
case 128: /* --debug */
1138
1058
tmpmax = strtoimax(arg, &tmp, 10);
1139
1059
if(errno != 0 or tmp == arg or *tmp != '\0'
1140
1060
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1141
argp_error(state, "Bad number of DH bits");
1061
fprintf(stderr, "Bad number of DH bits\n");
1143
1064
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1150
1071
delay = strtof(arg, &tmp);
1151
1072
if(errno != 0 or tmp == arg or *tmp != '\0'){
1152
argp_error(state, "Bad delay");
1073
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
1082
return ARGP_ERR_UNKNOWN;
1175
1087
struct argp argp = { .options = options, .parser = parse_opt,
1176
1088
.args_doc = "",
1177
1089
.doc = "Mandos client -- Get and decrypt"
1178
1090
" 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;
1091
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1092
if(ret == ARGP_ERR_UNKNOWN){
1093
fprintf(stderr, "Unknown error while parsing arguments\n");
1094
exitcode = EXIT_FAILURE;
1204
1107
mc.simple_poll = avahi_simple_poll_new();
1205
1108
if(mc.simple_poll == NULL){
1206
1109
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1207
exitcode = EX_UNAVAILABLE;
1110
exitcode = EXIT_FAILURE;
1212
1115
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1214
1117
perror("sigaddset");
1215
exitcode = EX_OSERR;
1118
exitcode = EXIT_FAILURE;
1218
1121
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1220
1123
perror("sigaddset");
1221
exitcode = EX_OSERR;
1124
exitcode = EXIT_FAILURE;
1224
1127
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1226
1129
perror("sigaddset");
1227
exitcode = EX_OSERR;
1130
exitcode = EXIT_FAILURE;
1230
1133
/* Need to check if the handler is SIG_IGN before handling:
1234
1137
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1236
1139
perror("sigaction");
1140
return EXIT_FAILURE;
1239
1142
if(old_sigterm_action.sa_handler != SIG_IGN){
1240
1143
ret = sigaction(SIGINT, &sigterm_action, NULL);
1242
1145
perror("sigaction");
1243
exitcode = EX_OSERR;
1146
exitcode = EXIT_FAILURE;
1247
1150
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1249
1152
perror("sigaction");
1153
return EXIT_FAILURE;
1252
1155
if(old_sigterm_action.sa_handler != SIG_IGN){
1253
1156
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1255
1158
perror("sigaction");
1256
exitcode = EX_OSERR;
1159
exitcode = EXIT_FAILURE;
1260
1163
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1262
1165
perror("sigaction");
1166
return EXIT_FAILURE;
1265
1168
if(old_sigterm_action.sa_handler != SIG_IGN){
1266
1169
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1268
1171
perror("sigaction");
1269
exitcode = EX_OSERR;
1172
exitcode = EXIT_FAILURE;
1287
/* Re-raise priviliges */
1294
1190
#ifdef __linux__
1295
1191
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1296
messages about the network interface to mess up the prompt */
1192
messages to mess up the prompt */
1297
1193
ret = klogctl(8, NULL, 5);
1298
1194
bool restore_loglevel = true;
1400
1278
#endif /* __linux__ */
1401
/* Lower privileges */
1403
if(take_down_interface){
1404
/* Lower privileges */
1410
/* Lower privileges permanently */
1288
/* Drop any group privileges we might have, just to be safe */
1295
/* Drop user privileges */
1297
/* Will we need privileges later? */
1298
if(take_down_interface){
1299
/* Drop user privileges temporarily */
1305
/* Drop user privileges permanently */
1422
1316
ret = init_gnutls_global(pubkey, seckey);
1424
1318
fprintf(stderr, "init_gnutls_global failed\n");
1425
exitcode = EX_UNAVAILABLE;
1319
exitcode = EXIT_FAILURE;
1428
1322
gnutls_initialized = true;
1446
1340
if(not init_gpgme(pubkey, seckey, tempdir)){
1447
1341
fprintf(stderr, "init_gpgme failed\n");
1448
exitcode = EX_UNAVAILABLE;
1342
exitcode = EXIT_FAILURE;
1451
1345
gpgme_initialized = true;
1622
1498
perror("ioctl SIOCGIFFLAGS");
1623
1499
} else if(network.ifr_flags & IFF_UP) {
1624
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1500
network.ifr_flags &= ~IFF_UP; /* clear flag */
1625
1501
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1627
1503
perror("ioctl SIOCSIFFLAGS");
1688
1564
sigemptyset(&old_sigterm_action.sa_mask);
1689
1565
old_sigterm_action.sa_handler = SIG_DFL;
1690
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1691
&old_sigterm_action,
1566
ret = sigaction(signal_received, &old_sigterm_action, NULL);
1694
1568
perror("sigaction");
1697
ret = raise(signal_received);
1698
} while(ret != 0 and errno == EINTR);
1703
TEMP_FAILURE_RETRY(pause());
1570
raise(signal_received);
1706
1573
return exitcode;