32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
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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() */
43
39
stdout, ferror(), remove() */
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40
#include <stdint.h> /* uint16_t, uint32_t */
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#include <stddef.h> /* NULL, size_t, ssize_t */
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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
42
#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(),
50
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strerror(), asprintf(), strcpy() */
71
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INET_ADDRSTRLEN, INET6_ADDRSTRLEN
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#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 */
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74
#include <argp.h> /* struct argp_option, error_t, struct
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argp_parse(), ARGP_KEY_ARG,
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ARGP_KEY_END, ARGP_ERR_UNKNOWN */
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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 */
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sigaction(), SIGTERM, sigaction,
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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" };
147
sig_atomic_t quit_now = 0;
148
int signal_received = 0;
151
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* Make additional room in "buffer" for at least BUFFER_SIZE more
152
143
* bytes. "buffer_capacity" is how much is currently allocated,
315
306
gpgme_recipient_t recipient;
316
307
recipient = result->recipients;
317
while(recipient != NULL){
318
fprintf(stderr, "Public key algorithm: %s\n",
319
gpgme_pubkey_algo_name(recipient->pubkey_algo));
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fprintf(stderr, "Key ID: %s\n", recipient->keyid);
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fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
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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));
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fprintf(stderr, "Key ID: %s\n", recipient->keyid);
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fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
316
recipient = recipient->next;
479
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static int init_gnutls_session(gnutls_session_t *session){
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/* GnuTLS session creation */
483
ret = gnutls_init(session, GNUTLS_SERVER);
487
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
475
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));
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);
483
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",
512
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
515
gnutls_deinit(*session);
518
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
493
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));
526
502
/* ignore client certificate if any. */
527
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);
539
516
static int start_mandos_communication(const char *ip, uint16_t port,
540
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AvahiIfIndex if_index,
542
int ret, tcp_sd = -1;
545
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struct sockaddr_in in;
546
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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;
550
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size_t buffer_length = 0;
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size_t buffer_capacity = 0;
529
ssize_t decrypted_buffer_size;
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gnutls_session_t session;
555
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int pf; /* Protocol family */
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tcp_sd = socket(pf, SOCK_STREAM, 0);
590
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perror("socket");
600
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memset(&to, 0, sizeof(to));
601
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if(af == AF_INET6){
602
to.in6.sin6_family = (sa_family_t)af;
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to.in6.sin6_family = (uint16_t)af;
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ret = inet_pton(af, ip, &to.in6.sin6_addr);
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} else { /* IPv4 */
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to.in.sin_family = (sa_family_t)af;
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ret = inet_pton(af, ip, &to.in.sin_addr);
610
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perror("inet_pton");
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fprintf(stderr, "Bad address: %s\n", ip);
620
579
if(af == AF_INET6){
621
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to.in6.sin6_port = htons(port); /* Spurious warnings from
628
587
if(if_index == AVAHI_IF_UNSPEC){
629
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fprintf(stderr, "An IPv6 link-local address is incomplete"
630
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" without a network interface\n");
634
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/* Set the network interface number as scope */
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to.in6.sin6_scope_id = (uint32_t)if_index;
685
633
if(af == AF_INET6){
686
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ret = connect(tcp_sd, &to.in6, sizeof(to));
688
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ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
692
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perror("connect");
702
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const char *out = mandos_protocol_version;
733
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fprintf(stderr, "Establishing TLS session with %s\n", ip);
741
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gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
749
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ret = gnutls_handshake(session);
754
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} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
756
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if(ret != GNUTLS_E_SUCCESS){
801
710
case GNUTLS_E_AGAIN:
803
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case GNUTLS_E_REHANDSHAKE:
805
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ret = gnutls_handshake(session);
811
715
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
813
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fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
814
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gnutls_perror(ret);
820
724
fprintf(stderr, "Unknown error while reading data from"
821
725
" encrypted session with Mandos server\n");
822
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gnutls_bye(session, GNUTLS_SHUT_RDWR);
832
736
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);
739
gnutls_bye(session, GNUTLS_SHUT_RDWR);
848
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if(buffer_length > 0){
849
ssize_t decrypted_buffer_size;
850
742
decrypted_buffer_size = pgp_packet_decrypt(buffer,
852
744
&decrypted_buffer);
853
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if(decrypted_buffer_size >= 0){
856
747
while(written < (size_t) decrypted_buffer_size){
862
748
ret = (int)fwrite(decrypted_buffer + written, 1,
863
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(size_t)decrypted_buffer_size - written,
865
751
if(ret == 0 and ferror(stdout)){
868
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fprintf(stderr, "Error writing encrypted data: %s\n",
869
754
strerror(errno));
874
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written += (size_t)ret;
761
free(decrypted_buffer);
880
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/* Shutdown procedure */
885
free(decrypted_buffer);
888
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
896
gnutls_deinit(session);
773
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
777
gnutls_deinit(session);
987
854
the callback function is called the Avahi server will free the
988
855
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)
857
if(!(avahi_s_service_resolver_new(mc.server, interface,
858
protocol, name, type, domain,
859
AVAHI_PROTO_INET6, 0,
860
resolve_callback, NULL)))
993
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fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
994
862
name, avahi_strerror(avahi_server_errno(mc.server)));
877
sig_atomic_t quit_now = 0;
1009
879
/* stop main loop after sigterm has been called */
1010
static void handle_sigterm(int sig){
880
static void handle_sigterm(__attribute__((unused)) int sig){
1015
signal_received = sig;
1016
885
int old_errno = errno;
1017
886
if(mc.simple_poll != NULL){
1018
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avahi_simple_poll_quit(mc.simple_poll);
1040
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" };
1043
915
bool gnutls_initialized = false;
1044
916
bool gpgme_initialized = false;
1045
917
float delay = 2.5f;
1047
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
919
struct sigaction old_sigterm_action;
1048
920
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
923
struct argp_option options[] = {
1073
924
{ .name = "debug", .key = 128,
1102
953
.arg = "SECONDS",
1103
954
.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
956
{ .name = NULL }
1117
959
error_t parse_opt(int key, char *arg,
1118
960
struct argp_state *state){
1121
962
case 128: /* --debug */
1138
979
tmpmax = strtoimax(arg, &tmp, 10);
1139
980
if(errno != 0 or tmp == arg or *tmp != '\0'
1140
981
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1141
argp_error(state, "Bad number of DH bits");
982
fprintf(stderr, "Bad number of DH bits\n");
1143
985
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1150
992
delay = strtof(arg, &tmp);
1151
993
if(errno != 0 or tmp == arg or *tmp != '\0'){
1152
argp_error(state, "Bad delay");
994
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
1003
return ARGP_ERR_UNKNOWN;
1175
1008
struct argp argp = { .options = options, .parser = parse_opt,
1176
1009
.args_doc = "",
1177
1010
.doc = "Mandos client -- Get and decrypt"
1178
1011
" 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;
1012
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1013
if(ret == ARGP_ERR_UNKNOWN){
1014
fprintf(stderr, "Unknown error while parsing arguments\n");
1015
exitcode = EXIT_FAILURE;
1204
1028
mc.simple_poll = avahi_simple_poll_new();
1205
1029
if(mc.simple_poll == NULL){
1206
1030
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1207
exitcode = EX_UNAVAILABLE;
1031
exitcode = EXIT_FAILURE;
1212
1036
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1214
1038
perror("sigaddset");
1215
exitcode = EX_OSERR;
1039
exitcode = EXIT_FAILURE;
1218
1042
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1220
1044
perror("sigaddset");
1221
exitcode = EX_OSERR;
1045
exitcode = EXIT_FAILURE;
1224
1048
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1226
1050
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;
1051
exitcode = EXIT_FAILURE;
1054
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1056
perror("sigaction");
1057
exitcode = EXIT_FAILURE;
1274
1061
/* If the interface is down, bring it up */
1275
1062
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
1063
#ifdef __linux__
1295
1064
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1296
messages about the network interface to mess up the prompt */
1065
messages to mess up the prompt */
1297
1066
ret = klogctl(8, NULL, 5);
1298
1067
bool restore_loglevel = true;
1336
1099
#endif /* __linux__ */
1337
exitcode = EX_OSERR;
1338
/* Lower privileges */
1100
exitcode = EXIT_FAILURE;
1346
1103
if((network.ifr_flags & IFF_UP) == 0){
1347
1104
network.ifr_flags |= IFF_UP;
1348
take_down_interface = true;
1349
1105
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1351
take_down_interface = false;
1352
1107
perror("ioctl SIOCSIFFLAGS");
1353
exitcode = EX_OSERR;
1108
exitcode = EXIT_FAILURE;
1354
1109
#ifdef __linux__
1355
1110
if(restore_loglevel){
1356
1111
ret = klogctl(7, NULL, 0);
1400
1146
#endif /* __linux__ */
1401
/* Lower privileges */
1403
if(take_down_interface){
1404
/* Lower privileges */
1410
/* Lower privileges permanently */
1422
1163
ret = init_gnutls_global(pubkey, seckey);
1424
1165
fprintf(stderr, "init_gnutls_global failed\n");
1425
exitcode = EX_UNAVAILABLE;
1166
exitcode = EXIT_FAILURE;
1428
1169
gnutls_initialized = true;
1435
tempdir_created = true;
1436
1172
if(mkdtemp(tempdir) == NULL){
1437
tempdir_created = false;
1438
1173
perror("mkdtemp");
1176
tempdir_created = true;
1446
1178
if(not init_gpgme(pubkey, seckey, tempdir)){
1447
1179
fprintf(stderr, "init_gpgme failed\n");
1448
exitcode = EX_UNAVAILABLE;
1180
exitcode = EXIT_FAILURE;
1451
1183
gpgme_initialized = true;
1186
if(interface[0] != '\0'){
1187
if_index = (AvahiIfIndex) if_nametoindex(interface);
1189
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1190
exitcode = EXIT_FAILURE;
1458
1195
if(connect_to != NULL){
1461
1198
char *address = strrchr(connect_to, ':');
1462
1199
if(address == NULL){
1463
1200
fprintf(stderr, "No colon in address\n");
1464
exitcode = EX_USAGE;
1201
exitcode = EXIT_FAILURE;
1474
1206
tmpmax = strtoimax(address+1, &tmp, 10);
1475
1207
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1476
1208
or tmpmax != (uint16_t)tmpmax){
1477
1209
fprintf(stderr, "Bad port number\n");
1478
exitcode = EX_USAGE;
1210
exitcode = EXIT_FAILURE;
1486
1213
port = (uint16_t)tmpmax;
1487
1214
*address = '\0';
1488
1215
address = connect_to;
1501
1223
ret = start_mandos_communication(address, port, if_index, af);
1507
exitcode = EX_NOHOST;
1510
exitcode = EX_USAGE;
1513
exitcode = EX_IOERR;
1516
exitcode = EX_PROTOCOL;
1519
exitcode = EX_OSERR;
1225
exitcode = EXIT_FAILURE;
1523
1227
exitcode = EXIT_SUCCESS;
1533
1233
AvahiServerConfig config;
1534
1234
/* Do not publish any local Zeroconf records */
1551
1251
if(mc.server == NULL){
1552
1252
fprintf(stderr, "Failed to create Avahi server: %s\n",
1553
1253
avahi_strerror(error));
1554
exitcode = EX_UNAVAILABLE;
1254
exitcode = EXIT_FAILURE;
1562
1258
/* Create the Avahi service browser */
1563
1259
sb = avahi_s_service_browser_new(mc.server, if_index,
1564
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1260
AVAHI_PROTO_INET6, "_mandos._tcp",
1565
1261
NULL, 0, browse_callback, NULL);
1566
1262
if(sb == NULL){
1567
1263
fprintf(stderr, "Failed to create service browser: %s\n",
1568
1264
avahi_strerror(avahi_server_errno(mc.server)));
1569
exitcode = EX_UNAVAILABLE;
1265
exitcode = EXIT_FAILURE;
1608
1300
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
1303
/* Removes the temp directory used by GPGME */
1644
1304
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
1347
return exitcode;