32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
33
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
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34
#define _FILE_OFFSET_BITS 64
40
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
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stdout, ferror(), remove() */
39
stdout, ferror(), sscanf(),
44
41
#include <stdint.h> /* uint16_t, uint32_t */
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#include <stddef.h> /* NULL, size_t, ssize_t */
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43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
47
srand(), strtof(), abort() */
48
#include <stdbool.h> /* bool, false, true */
45
#include <stdbool.h> /* bool, true */
49
46
#include <string.h> /* memset(), strcmp(), strlen(),
50
47
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
48
#include <sys/ioctl.h> /* ioctl */
52
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
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50
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
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SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
56
54
#include <sys/stat.h> /* open() */
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#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
56
struct in6_addr, inet_pton(),
59
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#include <fcntl.h> /* open() */
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#include <dirent.h> /* opendir(), struct dirent, readdir()
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#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
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#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
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#include <assert.h> /* assert() */
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#include <errno.h> /* perror(), errno */
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#include <time.h> /* nanosleep(), time() */
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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
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66
SIOCSIFFLAGS, if_indextoname(),
69
67
if_nametoindex(), IF_NAMESIZE */
70
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
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INET_ADDRSTRLEN, INET6_ADDRSTRLEN
68
#include <netinet/in.h>
73
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
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getuid(), getgid(), seteuid(),
70
getuid(), getgid(), setuid(),
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#include <arpa/inet.h> /* inet_pton(), htons */
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#include <iso646.h> /* not, or, and */
73
#include <iso646.h> /* not, and, or */
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74
#include <argp.h> /* struct argp_option, error_t, struct
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argp_state, struct argp,
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76
argp_parse(), ARGP_KEY_ARG,
81
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
#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 */
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79
#include <sys/klog.h> /* klogctl() */
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#endif /* __linux__ */
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83
/* All Avahi types, constants and functions
139
130
} mandos_context;
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/* global context so signal handler can reach it*/
142
mandos_context mc = { .simple_poll = NULL, .server = NULL,
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.dh_bits = 1024, .priority = "SECURE256"
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":!CTYPE-X.509:+CTYPE-OPENPGP" };
146
sig_atomic_t quit_now = 0;
147
int signal_received = 0;
150
* Make additional room in "buffer" for at least BUFFER_SIZE more
151
* bytes. "buffer_capacity" is how much is currently allocated,
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
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* "buffer_capacity" is how much is currently allocated,
152
135
* "buffer_length" is how much is already used.
154
size_t incbuffer(char **buffer, size_t buffer_length,
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size_t adjustbuffer(char **buffer, size_t buffer_length,
155
138
size_t buffer_capacity){
156
139
if(buffer_length + BUFFER_SIZE > buffer_capacity){
157
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
314
298
gpgme_recipient_t recipient;
315
299
recipient = result->recipients;
316
while(recipient != NULL){
317
fprintf(stderr, "Public key algorithm: %s\n",
318
gpgme_pubkey_algo_name(recipient->pubkey_algo));
319
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
320
fprintf(stderr, "Secret key available: %s\n",
321
recipient->status == GPG_ERR_NO_SECKEY
323
recipient = recipient->next;
301
while(recipient != NULL){
302
fprintf(stderr, "Public key algorithm: %s\n",
303
gpgme_pubkey_algo_name(recipient->pubkey_algo));
304
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
305
fprintf(stderr, "Secret key available: %s\n",
306
recipient->status == GPG_ERR_NO_SECKEY
308
recipient = recipient->next;
452
439
/* GnuTLS server initialization */
453
ret = gnutls_dh_params_init(&mc.dh_params);
440
ret = gnutls_dh_params_init(&mc->dh_params);
454
441
if(ret != GNUTLS_E_SUCCESS){
455
442
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
456
443
" %s\n", safer_gnutls_strerror(ret));
459
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
460
447
if(ret != GNUTLS_E_SUCCESS){
461
448
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
462
449
safer_gnutls_strerror(ret));
466
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
472
gnutls_certificate_free_credentials(mc.cred);
459
gnutls_certificate_free_credentials(mc->cred);
473
460
gnutls_global_deinit();
474
gnutls_dh_params_deinit(mc.dh_params);
461
gnutls_dh_params_deinit(mc->dh_params);
478
static int init_gnutls_session(gnutls_session_t *session){
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
480
468
/* GnuTLS session creation */
482
ret = gnutls_init(session, GNUTLS_SERVER);
486
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
469
ret = gnutls_init(session, GNUTLS_SERVER);
487
470
if(ret != GNUTLS_E_SUCCESS){
488
471
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
489
472
safer_gnutls_strerror(ret));
537
509
/* Called when a Mandos server is found */
538
510
static int start_mandos_communication(const char *ip, uint16_t port,
539
511
AvahiIfIndex if_index,
541
int ret, tcp_sd = -1;
544
struct sockaddr_in in;
545
struct sockaddr_in6 in6;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
547
516
char *buffer = NULL;
548
char *decrypted_buffer = NULL;
517
char *decrypted_buffer;
549
518
size_t buffer_length = 0;
550
519
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
553
524
gnutls_session_t session;
554
int pf; /* Protocol family */
568
fprintf(stderr, "Bad address family: %d\n", af);
572
ret = init_gnutls_session(&session);
526
ret = init_gnutls_session(mc, &session);
578
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
582
tcp_sd = socket(pf, SOCK_STREAM, 0);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
584
538
perror("socket");
543
if(if_indextoname((unsigned int)if_index, interface) == NULL){
544
perror("if_indextoname");
547
fprintf(stderr, "Binding to interface %s\n", interface);
592
550
memset(&to, 0, sizeof(to));
594
to.in6.sin6_family = (sa_family_t)af;
595
ret = inet_pton(af, ip, &to.in6.sin6_addr);
597
to.in.sin_family = (sa_family_t)af;
598
ret = inet_pton(af, ip, &to.in.sin_addr);
551
to.in6.sin6_family = AF_INET6;
552
/* It would be nice to have a way to detect if we were passed an
553
IPv4 address here. Now we assume an IPv6 address. */
554
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
601
556
perror("inet_pton");
605
560
fprintf(stderr, "Bad address: %s\n", ip);
609
to.in6.sin6_port = htons(port); /* Spurious warnings from
611
-Wunreachable-code */
613
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
614
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
616
if(if_index == AVAHI_IF_UNSPEC){
617
fprintf(stderr, "An IPv6 link-local address is incomplete"
618
" without a network interface\n");
621
/* Set the network interface number as scope */
622
to.in6.sin6_scope_id = (uint32_t)if_index;
625
to.in.sin_port = htons(port); /* Spurious warnings from
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
627
565
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
635
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
636
char interface[IF_NAMESIZE];
637
if(if_indextoname((unsigned int)if_index, interface) == NULL){
638
perror("if_indextoname");
640
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
641
ip, interface, port);
644
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
647
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
648
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
651
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
654
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
570
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
572
char addrstr[INET6_ADDRSTRLEN] = "";
573
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
574
sizeof(addrstr)) == NULL){
658
575
perror("inet_ntop");
660
577
if(strcmp(addrstr, ip) != 0){
800
682
fprintf(stderr, "Closing TLS session\n");
808
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
812
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
685
gnutls_bye(session, GNUTLS_SHUT_RDWR);
814
687
if(buffer_length > 0){
815
ssize_t decrypted_buffer_size;
816
decrypted_buffer_size = pgp_packet_decrypt(buffer,
688
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
818
690
&decrypted_buffer);
819
691
if(decrypted_buffer_size >= 0){
822
693
while(written < (size_t) decrypted_buffer_size){
827
694
ret = (int)fwrite(decrypted_buffer + written, 1,
828
695
(size_t)decrypted_buffer_size - written,
942
801
the callback function is called the Avahi server will free the
943
802
resolver for us. */
945
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
946
name, type, domain, protocol, 0,
947
resolve_callback, NULL) == NULL)
804
if(!(avahi_s_service_resolver_new(mc->server, interface,
805
protocol, name, type, domain,
806
AVAHI_PROTO_INET6, 0,
807
resolve_callback, mc)))
948
808
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
949
name, avahi_strerror(avahi_server_errno(mc.server)));
809
name, avahi_strerror(avahi_server_errno(mc->server)));
952
812
case AVAHI_BROWSER_REMOVE:
1057
881
.arg = "SECONDS",
1058
882
.doc = "Maximum delay to wait for interface startup",
1061
* These reproduce what we would get without ARGP_NO_HELP
1063
{ .name = "help", .key = '?',
1064
.doc = "Give this help list", .group = -1 },
1065
{ .name = "usage", .key = -3,
1066
.doc = "Give a short usage message", .group = -1 },
1067
{ .name = "version", .key = 'V',
1068
.doc = "Print program version", .group = -1 },
1069
884
{ .name = NULL }
1072
887
error_t parse_opt(int key, char *arg,
1073
888
struct argp_state *state){
1076
890
case 128: /* --debug */
1101
915
mc.priority = arg;
1103
917
case 131: /* --delay */
1105
delay = strtof(arg, &tmp);
1106
if(errno != 0 or tmp == arg or *tmp != '\0'){
1107
argp_error(state, "Bad delay");
918
ret = sscanf(arg, "%lf%n", &delay, &numchars);
919
if(ret < 1 or arg[numchars] != '\0'){
920
fprintf(stderr, "Bad delay\n");
1111
* These reproduce what we would get without ARGP_NO_HELP
1113
case '?': /* --help */
1114
argp_state_help(state, state->out_stream,
1115
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1116
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1117
case -3: /* --usage */
1118
argp_state_help(state, state->out_stream,
1119
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1120
case 'V': /* --version */
1121
fprintf(state->out_stream, "%s\n", argp_program_version);
1122
exit(argp_err_exit_status);
1125
929
return ARGP_ERR_UNKNOWN;
1130
934
struct argp argp = { .options = options, .parser = parse_opt,
1132
936
.doc = "Mandos client -- Get and decrypt"
1133
937
" passwords from a Mandos server" };
1134
ret = argp_parse(&argp, argc, argv,
1135
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1142
perror("argp_parse");
1143
exitcode = EX_OSERR;
1146
exitcode = EX_USAGE;
1152
avahi_set_log_function(empty_log);
1155
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1156
from the signal handler */
1157
/* Initialize the pseudo-RNG for Avahi */
1158
srand((unsigned int) time(NULL));
1159
mc.simple_poll = avahi_simple_poll_new();
1160
if(mc.simple_poll == NULL){
1161
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1162
exitcode = EXIT_FAILURE;
1166
sigemptyset(&sigterm_action.sa_mask);
1167
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1169
perror("sigaddset");
1170
exitcode = EXIT_FAILURE;
1173
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1175
perror("sigaddset");
1176
exitcode = EXIT_FAILURE;
1179
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1181
perror("sigaddset");
1182
exitcode = EXIT_FAILURE;
1185
/* Need to check if the handler is SIG_IGN before handling:
1186
| [[info:libc:Initial Signal Actions]] |
1187
| [[info:libc:Basic Signal Handling]] |
1189
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1191
perror("sigaction");
1192
return EXIT_FAILURE;
1194
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
ret = sigaction(SIGINT, &sigterm_action, NULL);
1197
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
1202
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1204
perror("sigaction");
1205
return EXIT_FAILURE;
1207
if(old_sigterm_action.sa_handler != SIG_IGN){
1208
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1210
perror("sigaction");
1211
exitcode = EXIT_FAILURE;
1215
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1217
perror("sigaction");
1218
return EXIT_FAILURE;
1220
if(old_sigterm_action.sa_handler != SIG_IGN){
1221
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1223
perror("sigaction");
938
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
939
if(ret == ARGP_ERR_UNKNOWN){
940
fprintf(stderr, "Unknown error while parsing arguments\n");
1224
941
exitcode = EXIT_FAILURE;
1229
946
/* If the interface is down, bring it up */
1230
if(interface[0] != '\0'){
1231
if_index = (AvahiIfIndex) if_nametoindex(interface);
1233
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1234
exitcode = EXIT_FAILURE;
1242
/* Re-raise priviliges */
1249
948
#ifdef __linux__
1250
949
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1251
messages about the network interface to mess up the prompt */
950
messages to mess up the prompt */
1252
951
ret = klogctl(8, NULL, 5);
1253
bool restore_loglevel = true;
1255
restore_loglevel = false;
1256
953
perror("klogctl");
1258
#endif /* __linux__ */
1260
957
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1262
959
perror("socket");
1263
960
exitcode = EXIT_FAILURE;
1264
961
#ifdef __linux__
1265
if(restore_loglevel){
1266
ret = klogctl(7, NULL, 0);
1271
#endif /* __linux__ */
1272
/* Lower privileges */
962
ret = klogctl(7, NULL, 0);
1280
969
strcpy(network.ifr_name, interface);
1283
972
perror("ioctl SIOCGIFFLAGS");
1284
973
#ifdef __linux__
1285
if(restore_loglevel){
1286
ret = klogctl(7, NULL, 0);
974
ret = klogctl(7, NULL, 0);
1291
#endif /* __linux__ */
1292
979
exitcode = EXIT_FAILURE;
1293
/* Lower privileges */
1301
982
if((network.ifr_flags & IFF_UP) == 0){
1302
983
network.ifr_flags |= IFF_UP;
1303
take_down_interface = true;
1304
984
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1306
take_down_interface = false;
1307
986
perror("ioctl SIOCSIFFLAGS");
1308
987
exitcode = EXIT_FAILURE;
1309
988
#ifdef __linux__
1310
if(restore_loglevel){
1311
ret = klogctl(7, NULL, 0);
1316
#endif /* __linux__ */
1317
/* Lower privileges */
989
ret = klogctl(7, NULL, 0);
1337
1008
perror("nanosleep");
1340
if(not take_down_interface){
1341
/* We won't need the socket anymore */
1342
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1011
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1347
1015
#ifdef __linux__
1348
if(restore_loglevel){
1349
/* Restores kernel loglevel to default */
1350
ret = klogctl(7, NULL, 0);
1355
#endif /* __linux__ */
1356
/* Lower privileges */
1358
if(take_down_interface){
1359
/* Lower privileges */
1365
/* Lower privileges permanently */
1377
ret = init_gnutls_global(pubkey, seckey);
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1379
1039
fprintf(stderr, "init_gnutls_global failed\n");
1380
1040
exitcode = EXIT_FAILURE;
1419
1073
exitcode = EXIT_FAILURE;
1429
tmpmax = strtoimax(address+1, &tmp, 10);
1430
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1431
or tmpmax != (uint16_t)tmpmax){
1077
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1078
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1079
or address[numchars+1] != '\0'){
1432
1080
fprintf(stderr, "Bad port number\n");
1433
1081
exitcode = EXIT_FAILURE;
1441
1084
port = (uint16_t)tmpmax;
1442
1085
*address = '\0';
1443
1086
address = connect_to;
1444
/* Colon in address indicates IPv6 */
1446
if(strchr(address, ':') != NULL){
1456
ret = start_mandos_communication(address, port, if_index, af);
1087
ret = start_mandos_communication(address, port, if_index, &mc);
1458
1089
exitcode = EXIT_FAILURE;