26
26
* along with this program. If not, see
27
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
29
* Contact the authors at <mandos@recompile.se>.
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
33
34
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
34
37
#define _FILE_OFFSET_BITS 64
36
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
43
stdout, ferror(), remove() */
41
44
#include <stdint.h> /* uint16_t, uint32_t */
42
45
#include <stddef.h> /* NULL, size_t, ssize_t */
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, true */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
#include <stdbool.h> /* bool, false, true */
46
49
#include <string.h> /* memset(), strcmp(), strlen(),
47
50
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
51
#include <sys/ioctl.h> /* ioctl */
49
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
53
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open(), S_ISREG */
55
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
56
struct in6_addr, inet_pton(),
58
inet_pton(), connect() */
58
59
#include <fcntl.h> /* open() */
59
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
61
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
62
64
#include <assert.h> /* assert() */
63
#include <errno.h> /* perror(), errno */
64
#include <time.h> /* nanosleep(), time() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
65
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
66
69
SIOCSIFFLAGS, if_indextoname(),
67
70
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
69
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit() */
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
78
#include <iso646.h> /* not, or, and */
74
79
#include <argp.h> /* struct argp_option, error_t, struct
75
80
argp_state, struct argp,
76
81
argp_parse(), ARGP_KEY_ARG,
77
82
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
88
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
89
WEXITSTATUS(), WTERMSIG() */
90
#include <grp.h> /* setgroups() */
79
93
#include <sys/klog.h> /* klogctl() */
94
#endif /* __linux__ */
83
97
/* All Avahi types, constants and functions
160
251
* Helper function to insert pub and seckey to the engine keyring.
162
253
bool import_key(const char *filename){
164
256
gpgme_data_t pgp_data;
166
258
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
172
264
rc = gpgme_data_new_from_fd(&pgp_data, fd);
173
265
if(rc != GPG_ERR_NO_ERROR){
174
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
266
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
267
gpgme_strsource(rc), gpgme_strerror(rc));
179
rc = gpgme_op_import(mc->ctx, pgp_data);
271
rc = gpgme_op_import(mc.ctx, pgp_data);
180
272
if(rc != GPG_ERR_NO_ERROR){
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
273
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
274
gpgme_strsource(rc), gpgme_strerror(rc));
186
278
ret = (int)TEMP_FAILURE_RETRY(close(fd));
280
perror_plus("close");
190
282
gpgme_data_release(pgp_data);
195
fprintf(stderr, "Initialize gpgme\n");
287
fprintf_plus(stderr, "Initializing GPGME\n");
199
291
gpgme_check_version(NULL);
200
292
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
201
293
if(rc != GPG_ERR_NO_ERROR){
202
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
294
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
295
gpgme_strsource(rc), gpgme_strerror(rc));
207
/* Set GPGME home directory for the OpenPGP engine only */
299
/* Set GPGME home directory for the OpenPGP engine only */
208
300
rc = gpgme_get_engine_info(&engine_info);
209
301
if(rc != GPG_ERR_NO_ERROR){
210
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
gpgme_strsource(rc), gpgme_strerror(rc));
302
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
303
gpgme_strsource(rc), gpgme_strerror(rc));
214
306
while(engine_info != NULL){
254
347
ssize_t plaintext_length = 0;
257
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
350
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
260
353
/* Create new GPGME data buffer from memory cryptotext */
261
354
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
263
356
if(rc != GPG_ERR_NO_ERROR){
264
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
265
gpgme_strsource(rc), gpgme_strerror(rc));
357
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
358
gpgme_strsource(rc), gpgme_strerror(rc));
269
362
/* Create new empty GPGME data buffer for the plaintext */
270
363
rc = gpgme_data_new(&dh_plain);
271
364
if(rc != GPG_ERR_NO_ERROR){
272
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
273
gpgme_strsource(rc), gpgme_strerror(rc));
365
fprintf_plus(stderr, "Mandos plugin mandos-client: "
366
"bad gpgme_data_new: %s: %s\n",
367
gpgme_strsource(rc), gpgme_strerror(rc));
274
368
gpgme_data_release(dh_crypto);
278
372
/* Decrypt data from the cryptotext data buffer to the plaintext
280
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
374
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
281
375
if(rc != GPG_ERR_NO_ERROR){
282
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
283
gpgme_strsource(rc), gpgme_strerror(rc));
376
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
377
gpgme_strsource(rc), gpgme_strerror(rc));
284
378
plaintext_length = -1;
286
380
gpgme_decrypt_result_t result;
287
result = gpgme_op_decrypt_result(mc->ctx);
381
result = gpgme_op_decrypt_result(mc.ctx);
288
382
if(result == NULL){
289
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
383
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
291
fprintf(stderr, "Unsupported algorithm: %s\n",
292
result->unsupported_algorithm);
293
fprintf(stderr, "Wrong key usage: %u\n",
294
result->wrong_key_usage);
385
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
386
result->unsupported_algorithm);
387
fprintf_plus(stderr, "Wrong key usage: %u\n",
388
result->wrong_key_usage);
295
389
if(result->file_name != NULL){
296
fprintf(stderr, "File name: %s\n", result->file_name);
390
fprintf_plus(stderr, "File name: %s\n", result->file_name);
298
392
gpgme_recipient_t recipient;
299
393
recipient = result->recipients;
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;
394
while(recipient != NULL){
395
fprintf_plus(stderr, "Public key algorithm: %s\n",
396
gpgme_pubkey_algo_name
397
(recipient->pubkey_algo));
398
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
399
fprintf_plus(stderr, "Secret key available: %s\n",
400
recipient->status == GPG_ERR_NO_SECKEY
402
recipient = recipient->next;
409
501
/* OpenPGP credentials */
410
gnutls_certificate_allocate_credentials(&mc->cred);
502
ret = gnutls_certificate_allocate_credentials(&mc.cred);
411
503
if(ret != GNUTLS_E_SUCCESS){
412
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
416
safer_gnutls_strerror(ret));
504
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
505
safer_gnutls_strerror(ret));
417
506
gnutls_global_deinit();
422
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
423
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
511
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
512
" secret key %s as GnuTLS credentials\n",
427
517
ret = gnutls_certificate_set_openpgp_key_file
428
(mc->cred, pubkeyfilename, seckeyfilename,
518
(mc.cred, pubkeyfilename, seckeyfilename,
429
519
GNUTLS_OPENPGP_FMT_BASE64);
430
520
if(ret != GNUTLS_E_SUCCESS){
432
"Error[%d] while reading the OpenPGP key pair ('%s',"
433
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
434
fprintf(stderr, "The GnuTLS error is: %s\n",
435
safer_gnutls_strerror(ret));
522
"Error[%d] while reading the OpenPGP key pair ('%s',"
523
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
524
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
525
safer_gnutls_strerror(ret));
439
529
/* GnuTLS server initialization */
440
ret = gnutls_dh_params_init(&mc->dh_params);
530
ret = gnutls_dh_params_init(&mc.dh_params);
441
531
if(ret != GNUTLS_E_SUCCESS){
442
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
443
" %s\n", safer_gnutls_strerror(ret));
532
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
533
" initialization: %s\n",
534
safer_gnutls_strerror(ret));
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
537
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
447
538
if(ret != GNUTLS_E_SUCCESS){
448
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
449
safer_gnutls_strerror(ret));
539
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
540
safer_gnutls_strerror(ret));
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
544
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
459
gnutls_certificate_free_credentials(mc->cred);
550
gnutls_certificate_free_credentials(mc.cred);
460
551
gnutls_global_deinit();
461
gnutls_dh_params_deinit(mc->dh_params);
552
gnutls_dh_params_deinit(mc.dh_params);
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
556
static int init_gnutls_session(gnutls_session_t *session){
468
558
/* GnuTLS session creation */
469
ret = gnutls_init(session, GNUTLS_SERVER);
560
ret = gnutls_init(session, GNUTLS_SERVER);
564
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
470
565
if(ret != GNUTLS_E_SUCCESS){
471
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
472
safer_gnutls_strerror(ret));
567
"Error in GnuTLS session initialization: %s\n",
568
safer_gnutls_strerror(ret));
477
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
574
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
576
gnutls_deinit(*session);
579
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
478
580
if(ret != GNUTLS_E_SUCCESS){
479
fprintf(stderr, "Syntax error at: %s\n", err);
480
fprintf(stderr, "GnuTLS error: %s\n",
481
safer_gnutls_strerror(ret));
581
fprintf_plus(stderr, "Syntax error at: %s\n", err);
582
fprintf_plus(stderr, "GnuTLS error: %s\n",
583
safer_gnutls_strerror(ret));
482
584
gnutls_deinit(*session);
487
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
590
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
593
gnutls_deinit(*session);
596
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
489
597
if(ret != GNUTLS_E_SUCCESS){
490
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
491
safer_gnutls_strerror(ret));
598
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
599
safer_gnutls_strerror(ret));
492
600
gnutls_deinit(*session);
496
604
/* ignore client certificate if any. */
497
gnutls_certificate_server_set_request(*session,
605
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
500
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
607
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
509
616
/* Called when a Mandos server is found */
510
617
static int start_mandos_communication(const char *ip, uint16_t port,
511
618
AvahiIfIndex if_index,
620
int ret, tcp_sd = -1;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
623
struct sockaddr_in in;
624
struct sockaddr_in6 in6;
516
626
char *buffer = NULL;
517
char *decrypted_buffer;
627
char *decrypted_buffer = NULL;
518
628
size_t buffer_length = 0;
519
629
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
524
632
gnutls_session_t session;
526
ret = init_gnutls_session(mc, &session);
633
int pf; /* Protocol family */
650
fprintf_plus(stderr, "Bad address family: %d\n", af);
655
ret = init_gnutls_session(&session);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
661
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
662
PRIu16 "\n", ip, port);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
665
tcp_sd = socket(pf, SOCK_STREAM, 0);
668
perror_plus("socket");
543
if(if_indextoname((unsigned int)if_index, interface) == NULL){
544
perror("if_indextoname");
547
fprintf(stderr, "Binding to interface %s\n", interface);
550
678
memset(&to, 0, sizeof(to));
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);
680
to.in6.sin6_family = (sa_family_t)af;
681
ret = inet_pton(af, ip, &to.in6.sin6_addr);
683
to.in.sin_family = (sa_family_t)af;
684
ret = inet_pton(af, ip, &to.in.sin_addr);
688
perror_plus("inet_pton");
560
fprintf(stderr, "Bad address: %s\n", ip);
694
fprintf_plus(stderr, "Bad address: %s\n", ip);
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
699
to.in6.sin6_port = htons(port); /* Spurious warnings from
701
-Wunreachable-code */
703
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
704
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
706
if(if_index == AVAHI_IF_UNSPEC){
707
fprintf_plus(stderr, "An IPv6 link-local address is"
708
" incomplete without a network interface\n");
712
/* Set the network interface number as scope */
713
to.in6.sin6_scope_id = (uint32_t)if_index;
716
to.in.sin_port = htons(port); /* Spurious warnings from
565
718
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
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){
727
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
728
char interface[IF_NAMESIZE];
729
if(if_indextoname((unsigned int)if_index, interface) == NULL){
730
perror_plus("if_indextoname");
732
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16
733
"\n", ip, interface, port);
736
fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",
739
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
740
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
743
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
746
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
750
perror_plus("inet_ntop");
577
752
if(strcmp(addrstr, ip) != 0){
578
fprintf(stderr, "Canonical address form: %s\n", addrstr);
753
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
583
ret = connect(tcp_sd, &to.in, sizeof(to));
764
ret = connect(tcp_sd, &to.in6, sizeof(to));
766
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
769
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
771
perror_plus("connect");
589
782
const char *out = mandos_protocol_version;
815
1086
case AVAHI_BROWSER_ALL_FOR_NOW:
816
1087
case AVAHI_BROWSER_CACHE_EXHAUSTED:
818
fprintf(stderr, "No Mandos server found, still searching...\n");
1089
fprintf_plus(stderr, "No Mandos server found, still"
1096
/* Signal handler that stops main loop after SIGTERM */
1097
static void handle_sigterm(int sig){
1102
signal_received = sig;
1103
int old_errno = errno;
1104
/* set main loop to exit */
1105
if(mc.simple_poll != NULL){
1106
avahi_simple_poll_quit(mc.simple_poll);
1111
bool get_flags(const char *ifname, struct ifreq *ifr){
1114
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1116
perror_plus("socket");
1119
strcpy(ifr->ifr_name, ifname);
1120
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1123
perror_plus("ioctl SIOCGIFFLAGS");
1130
bool good_flags(const char *ifname, const struct ifreq *ifr){
1132
/* Reject the loopback device */
1133
if(ifr->ifr_flags & IFF_LOOPBACK){
1135
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1140
/* Accept point-to-point devices only if connect_to is specified */
1141
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1143
fprintf_plus(stderr, "Accepting point-to-point interface"
1144
" \"%s\"\n", ifname);
1148
/* Otherwise, reject non-broadcast-capable devices */
1149
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1151
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1152
" \"%s\"\n", ifname);
1156
/* Reject non-ARP interfaces (including dummy interfaces) */
1157
if(ifr->ifr_flags & IFF_NOARP){
1159
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1165
/* Accept this device */
1167
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1173
* This function determines if a directory entry in /sys/class/net
1174
* corresponds to an acceptable network device.
1175
* (This function is passed to scandir(3) as a filter function.)
1177
int good_interface(const struct dirent *if_entry){
1178
if(if_entry->d_name[0] == '.'){
1183
if(not get_flags(if_entry->d_name, &ifr)){
1185
fprintf_plus(stderr, "Failed to get flags for interface "
1186
"\"%s\"\n", if_entry->d_name);
1191
if(not good_flags(if_entry->d_name, &ifr)){
1198
* This function determines if a directory entry in /sys/class/net
1199
* corresponds to an acceptable network device which is up.
1200
* (This function is passed to scandir(3) as a filter function.)
1202
int up_interface(const struct dirent *if_entry){
1203
if(if_entry->d_name[0] == '.'){
1208
if(not get_flags(if_entry->d_name, &ifr)){
1210
fprintf_plus(stderr, "Failed to get flags for interface "
1211
"\"%s\"\n", if_entry->d_name);
1216
/* Reject down interfaces */
1217
if(not (ifr.ifr_flags & IFF_UP)){
1219
fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",
1225
/* Reject non-running interfaces */
1226
if(not (ifr.ifr_flags & IFF_RUNNING)){
1228
fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",
1234
if(not good_flags(if_entry->d_name, &ifr)){
1240
int notdotentries(const struct dirent *direntry){
1241
/* Skip "." and ".." */
1242
if(direntry->d_name[0] == '.'
1243
and (direntry->d_name[1] == '\0'
1244
or (direntry->d_name[1] == '.'
1245
and direntry->d_name[2] == '\0'))){
1251
/* Is this directory entry a runnable program? */
1252
int runnable_hook(const struct dirent *direntry){
1257
if((direntry->d_name)[0] == '\0'){
1262
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1263
"abcdefghijklmnopqrstuvwxyz"
1266
if((direntry->d_name)[sret] != '\0'){
1267
/* Contains non-allowed characters */
1269
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1275
char *fullname = NULL;
1276
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1278
perror_plus("asprintf");
1282
ret = stat(fullname, &st);
1285
perror_plus("Could not stat hook");
1289
if(not (S_ISREG(st.st_mode))){
1290
/* Not a regular file */
1292
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1297
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1298
/* Not executable */
1300
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1306
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1312
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1314
struct timespec now;
1315
struct timespec waited_time;
1316
intmax_t block_time;
1319
if(mc.current_server == NULL){
1321
fprintf_plus(stderr, "Wait until first server is found."
1324
ret = avahi_simple_poll_iterate(s, -1);
1327
fprintf_plus(stderr, "Check current_server if we should run"
1330
/* the current time */
1331
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1333
perror_plus("clock_gettime");
1336
/* Calculating in ms how long time between now and server
1337
who we visted longest time ago. Now - last seen. */
1338
waited_time.tv_sec = (now.tv_sec
1339
- mc.current_server->last_seen.tv_sec);
1340
waited_time.tv_nsec = (now.tv_nsec
1341
- mc.current_server->last_seen.tv_nsec);
1342
/* total time is 10s/10,000ms.
1343
Converting to s from ms by dividing by 1,000,
1344
and ns to ms by dividing by 1,000,000. */
1345
block_time = ((retry_interval
1346
- ((intmax_t)waited_time.tv_sec * 1000))
1347
- ((intmax_t)waited_time.tv_nsec / 1000000));
1350
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1354
if(block_time <= 0){
1355
ret = start_mandos_communication(mc.current_server->ip,
1356
mc.current_server->port,
1357
mc.current_server->if_index,
1358
mc.current_server->af);
1360
avahi_simple_poll_quit(mc.simple_poll);
1363
ret = clock_gettime(CLOCK_MONOTONIC,
1364
&mc.current_server->last_seen);
1366
perror_plus("clock_gettime");
1369
mc.current_server = mc.current_server->next;
1370
block_time = 0; /* Call avahi to find new Mandos
1371
servers, but don't block */
1374
ret = avahi_simple_poll_iterate(s, (int)block_time);
1377
if (ret > 0 or errno != EINTR){
1378
return (ret != 1) ? ret : 0;
1384
bool run_network_hooks(const char *mode, const char *interface,
1386
struct dirent **direntries;
1387
struct dirent *direntry;
1389
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1392
perror_plus("scandir");
1394
int devnull = open("/dev/null", O_RDONLY);
1395
for(int i = 0; i < numhooks; i++){
1396
direntry = direntries[i];
1397
char *fullname = NULL;
1398
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1400
perror_plus("asprintf");
1404
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1407
pid_t hook_pid = fork();
1410
/* Raise privileges */
1414
perror_plus("seteuid");
1416
/* Raise privileges even more */
1420
perror_plus("setuid");
1426
perror_plus("setgid");
1428
/* Reset supplementary groups */
1430
ret = setgroups(0, NULL);
1432
perror_plus("setgroups");
1434
fprintf_plus(stderr, "Child: getuid() = %d\n", getuid());
1435
fprintf_plus(stderr, "Child: geteuid() = %d\n", geteuid());
1436
dup2(devnull, STDIN_FILENO);
1438
dup2(STDERR_FILENO, STDOUT_FILENO);
1439
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1441
perror_plus("setenv");
1444
ret = setenv("DEVICE", interface, 1);
1446
perror_plus("setenv");
1449
ret = setenv("VERBOSE", debug ? "1" : "0", 1);
1451
perror_plus("setenv");
1454
ret = setenv("MODE", mode, 1);
1456
perror_plus("setenv");
1460
ret = asprintf(&delaystring, "%f", delay);
1462
perror_plus("asprintf");
1465
ret = setenv("DELAY", delaystring, 1);
1468
perror_plus("setenv");
1472
ret = execl(fullname, direntry->d_name, mode, NULL);
1473
perror_plus("execl");
1476
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1477
perror_plus("waitpid");
1481
if(WIFEXITED(status)){
1482
if(WEXITSTATUS(status) != 0){
1483
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1484
" with status %d\n", direntry->d_name,
1485
WEXITSTATUS(status));
1489
} else if(WIFSIGNALED(status)){
1490
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1491
" signal %d\n", direntry->d_name,
1496
fprintf_plus(stderr, "Warning: network hook \"%s\""
1497
" crashed\n", direntry->d_name);
1504
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
824
1513
int main(int argc, char *argv[]){
825
1514
AvahiSServiceBrowser *sb = NULL;
828
1517
intmax_t tmpmax;
830
1519
int exitcode = EXIT_SUCCESS;
831
const char *interface = "eth0";
1520
const char *interface = "";
832
1521
struct ifreq network;
1523
bool take_down_interface = false;
836
char *connect_to = NULL;
837
1526
char tempdir[] = "/tmp/mandosXXXXXX";
838
1527
bool tempdir_created = false;
839
1528
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
840
1529
const char *seckey = PATHDIR "/" SECKEY;
841
1530
const char *pubkey = PATHDIR "/" PUBKEY;
843
mandos_context mc = { .simple_poll = NULL, .server = NULL,
844
.dh_bits = 1024, .priority = "SECURE256"
845
":!CTYPE-X.509:+CTYPE-OPENPGP" };
846
1532
bool gnutls_initialized = false;
847
1533
bool gpgme_initialized = false;
1535
double retry_interval = 10; /* 10s between trying a server and
1536
retrying the same server again */
1538
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1539
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1544
/* Lower any group privileges we might have, just to be safe */
1548
perror_plus("setgid");
1551
/* Lower user privileges (temporarily) */
1555
perror_plus("seteuid");
851
1563
struct argp_option options[] = {
915
1645
mc.priority = arg;
917
1647
case 131: /* --delay */
918
ret = sscanf(arg, "%lf%n", &delay, &numchars);
919
if(ret < 1 or arg[numchars] != '\0'){
920
fprintf(stderr, "Bad delay\n");
1649
delay = strtof(arg, &tmp);
1650
if(errno != 0 or tmp == arg or *tmp != '\0'){
1651
argp_error(state, "Bad delay");
1653
case 132: /* --retry */
1655
retry_interval = strtod(arg, &tmp);
1656
if(errno != 0 or tmp == arg or *tmp != '\0'
1657
or (retry_interval * 1000) > INT_MAX
1658
or retry_interval < 0){
1659
argp_error(state, "Bad retry interval");
1662
case 133: /* --network-hook-dir */
1666
* These reproduce what we would get without ARGP_NO_HELP
1668
case '?': /* --help */
1669
argp_state_help(state, state->out_stream,
1670
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1671
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1672
case -3: /* --usage */
1673
argp_state_help(state, state->out_stream,
1674
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1675
case 'V': /* --version */
1676
fprintf_plus(state->out_stream,
1677
"Mandos plugin mandos-client: ");
1678
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1679
exit(argp_err_exit_status);
929
1682
return ARGP_ERR_UNKNOWN;
934
1687
struct argp argp = { .options = options, .parser = parse_opt,
936
1689
.doc = "Mandos client -- Get and decrypt"
937
1690
" passwords from a Mandos server" };
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");
1691
ret = argp_parse(&argp, argc, argv,
1692
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1699
perror_plus("argp_parse");
1700
exitcode = EX_OSERR;
1703
exitcode = EX_USAGE;
1709
/* Work around Debian bug #633582:
1710
<http://bugs.debian.org/633582> */
1712
/* Re-raise priviliges */
1716
perror_plus("seteuid");
1720
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1721
int seckey_fd = open(seckey, O_RDONLY);
1722
if(seckey_fd == -1){
1723
perror_plus("open");
1725
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1727
perror_plus("fstat");
1729
if(S_ISREG(st.st_mode)
1730
and st.st_uid == 0 and st.st_gid == 0){
1731
ret = fchown(seckey_fd, uid, gid);
1733
perror_plus("fchown");
1737
TEMP_FAILURE_RETRY(close(seckey_fd));
1741
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1742
int pubkey_fd = open(pubkey, O_RDONLY);
1743
if(pubkey_fd == -1){
1744
perror_plus("open");
1746
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1748
perror_plus("fstat");
1750
if(S_ISREG(st.st_mode)
1751
and st.st_uid == 0 and st.st_gid == 0){
1752
ret = fchown(pubkey_fd, uid, gid);
1754
perror_plus("fchown");
1758
TEMP_FAILURE_RETRY(close(pubkey_fd));
1762
/* Lower privileges */
1766
perror_plus("seteuid");
1771
/* Run network hooks */
1772
if(not run_network_hooks("start", interface, delay)){
1777
avahi_set_log_function(empty_log);
1780
if(interface[0] == '\0'){
1781
struct dirent **direntries;
1782
/* First look for interfaces that are up */
1783
ret = scandir(sys_class_net, &direntries, up_interface,
1786
/* No up interfaces, look for any good interfaces */
1788
ret = scandir(sys_class_net, &direntries, good_interface,
1792
/* Pick the first interface returned */
1793
interface = strdup(direntries[0]->d_name);
1795
fprintf_plus(stderr, "Using interface \"%s\"\n", interface);
1797
if(interface == NULL){
1798
perror_plus("malloc");
1800
exitcode = EXIT_FAILURE;
1806
fprintf_plus(stderr, "Could not find a network interface\n");
941
1807
exitcode = EXIT_FAILURE;
1812
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1813
from the signal handler */
1814
/* Initialize the pseudo-RNG for Avahi */
1815
srand((unsigned int) time(NULL));
1816
mc.simple_poll = avahi_simple_poll_new();
1817
if(mc.simple_poll == NULL){
1818
fprintf_plus(stderr,
1819
"Avahi: Failed to create simple poll object.\n");
1820
exitcode = EX_UNAVAILABLE;
1824
sigemptyset(&sigterm_action.sa_mask);
1825
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1827
perror_plus("sigaddset");
1828
exitcode = EX_OSERR;
1831
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1833
perror_plus("sigaddset");
1834
exitcode = EX_OSERR;
1837
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1839
perror_plus("sigaddset");
1840
exitcode = EX_OSERR;
1843
/* Need to check if the handler is SIG_IGN before handling:
1844
| [[info:libc:Initial Signal Actions]] |
1845
| [[info:libc:Basic Signal Handling]] |
1847
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1849
perror_plus("sigaction");
1852
if(old_sigterm_action.sa_handler != SIG_IGN){
1853
ret = sigaction(SIGINT, &sigterm_action, NULL);
1855
perror_plus("sigaction");
1856
exitcode = EX_OSERR;
1860
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1862
perror_plus("sigaction");
1865
if(old_sigterm_action.sa_handler != SIG_IGN){
1866
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1868
perror_plus("sigaction");
1869
exitcode = EX_OSERR;
1873
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1875
perror_plus("sigaction");
1878
if(old_sigterm_action.sa_handler != SIG_IGN){
1879
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1881
perror_plus("sigaction");
1882
exitcode = EX_OSERR;
946
1887
/* If the interface is down, bring it up */
1888
if(strcmp(interface, "none") != 0){
1889
if_index = (AvahiIfIndex) if_nametoindex(interface);
1891
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1892
exitcode = EX_UNAVAILABLE;
1900
/* Re-raise priviliges */
1904
perror_plus("seteuid");
948
1907
#ifdef __linux__
949
1908
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
950
messages to mess up the prompt */
1909
messages about the network interface to mess up the prompt */
951
1910
ret = klogctl(8, NULL, 5);
1911
bool restore_loglevel = true;
1913
restore_loglevel = false;
1914
perror_plus("klogctl");
1916
#endif /* __linux__ */
957
1918
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
960
exitcode = EXIT_FAILURE;
1920
perror_plus("socket");
1921
exitcode = EX_OSERR;
961
1922
#ifdef __linux__
962
ret = klogctl(7, NULL, 0);
1923
if(restore_loglevel){
1924
ret = klogctl(7, NULL, 0);
1926
perror_plus("klogctl");
1929
#endif /* __linux__ */
1930
/* Lower privileges */
1934
perror_plus("seteuid");
969
1938
strcpy(network.ifr_name, interface);
970
1939
ret = ioctl(sd, SIOCGIFFLAGS, &network);
972
perror("ioctl SIOCGIFFLAGS");
1941
perror_plus("ioctl SIOCGIFFLAGS");
973
1942
#ifdef __linux__
974
ret = klogctl(7, NULL, 0);
1943
if(restore_loglevel){
1944
ret = klogctl(7, NULL, 0);
1946
perror_plus("klogctl");
1949
#endif /* __linux__ */
1950
exitcode = EX_OSERR;
1951
/* Lower privileges */
1955
perror_plus("seteuid");
979
exitcode = EXIT_FAILURE;
982
1959
if((network.ifr_flags & IFF_UP) == 0){
983
1960
network.ifr_flags |= IFF_UP;
1961
take_down_interface = true;
984
1962
ret = ioctl(sd, SIOCSIFFLAGS, &network);
986
perror("ioctl SIOCSIFFLAGS");
987
exitcode = EXIT_FAILURE;
1964
take_down_interface = false;
1965
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1966
exitcode = EX_OSERR;
988
1967
#ifdef __linux__
989
ret = klogctl(7, NULL, 0);
1968
if(restore_loglevel){
1969
ret = klogctl(7, NULL, 0);
1971
perror_plus("klogctl");
1974
#endif /* __linux__ */
1975
/* Lower privileges */
1979
perror_plus("seteuid");
997
/* sleep checking until interface is running */
1984
/* Sleep checking until interface is running.
1985
Check every 0.25s, up to total time of delay */
998
1986
for(int i=0; i < delay * 4; i++){
999
1987
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1001
perror("ioctl SIOCGIFFLAGS");
1989
perror_plus("ioctl SIOCGIFFLAGS");
1002
1990
} else if(network.ifr_flags & IFF_RUNNING){
1005
1993
struct timespec sleeptime = { .tv_nsec = 250000000 };
1006
1994
ret = nanosleep(&sleeptime, NULL);
1007
1995
if(ret == -1 and errno != EINTR){
1008
perror("nanosleep");
1996
perror_plus("nanosleep");
1011
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1999
if(not take_down_interface){
2000
/* We won't need the socket anymore */
2001
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2003
perror_plus("close");
1015
2006
#ifdef __linux__
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
2007
if(restore_loglevel){
2008
/* Restores kernel loglevel to default */
2009
ret = klogctl(7, NULL, 0);
2011
perror_plus("klogctl");
2014
#endif /* __linux__ */
2015
/* Lower privileges */
2017
/* Lower privileges */
2020
perror_plus("seteuid");
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1039
fprintf(stderr, "init_gnutls_global failed\n");
1040
exitcode = EXIT_FAILURE;
2028
ret = init_gnutls_global(pubkey, seckey);
2030
fprintf_plus(stderr, "init_gnutls_global failed\n");
2031
exitcode = EX_UNAVAILABLE;
1043
2034
gnutls_initialized = true;
1046
2041
if(mkdtemp(tempdir) == NULL){
2042
perror_plus("mkdtemp");
1050
2045
tempdir_created = true;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1053
fprintf(stderr, "init_gpgme failed\n");
1054
exitcode = EXIT_FAILURE;
2051
if(not init_gpgme(pubkey, seckey, tempdir)){
2052
fprintf_plus(stderr, "init_gpgme failed\n");
2053
exitcode = EX_UNAVAILABLE;
1057
2056
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;
1179
2216
gpgme_release(mc.ctx);
1182
/* Removes the temp directory used by GPGME */
2219
/* Cleans up the circular linked list of Mandos servers the client
2221
if(mc.current_server != NULL){
2222
mc.current_server->prev->next = NULL;
2223
while(mc.current_server != NULL){
2224
server *next = mc.current_server->next;
2225
free(mc.current_server);
2226
mc.current_server = next;
2230
/* Run network hooks */
2231
run_network_hooks("stop", interface, delay);
2233
/* Re-raise priviliges */
2238
perror_plus("seteuid");
2241
/* Take down the network interface */
2242
if(take_down_interface and geteuid() == 0){
2243
ret = ioctl(sd, SIOCGIFFLAGS, &network);
2245
perror_plus("ioctl SIOCGIFFLAGS");
2246
} else if(network.ifr_flags & IFF_UP){
2247
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2248
ret = ioctl(sd, SIOCSIFFLAGS, &network);
2250
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2253
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2255
perror_plus("close");
2259
/* Lower privileges permanently */
2263
perror_plus("setuid");
2266
/* Removes the GPGME temp directory and all files inside */
1183
2267
if(tempdir_created){
1185
struct dirent *direntry;
1186
d = opendir(tempdir);
1188
if(errno != ENOENT){
1193
direntry = readdir(d);
1194
if(direntry == NULL){
1197
/* Skip "." and ".." */
1198
if(direntry->d_name[0] == '.'
1199
and (direntry->d_name[1] == '\0'
1200
or (direntry->d_name[1] == '.'
1201
and direntry->d_name[2] == '\0'))){
2268
struct dirent **direntries = NULL;
2269
struct dirent *direntry = NULL;
2270
int numentries = scandir(tempdir, &direntries, notdotentries,
2272
if (numentries > 0){
2273
for(int i = 0; i < numentries; i++){
2274
direntry = direntries[i];
1204
2275
char *fullname = NULL;
1205
2276
ret = asprintf(&fullname, "%s/%s", tempdir,
1206
2277
direntry->d_name);
2279
perror_plus("asprintf");
1211
2282
ret = remove(fullname);
1213
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
2284
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
1216
2287
free(fullname);
2291
/* need to clean even if 0 because man page doesn't specify */
2293
if (numentries == -1){
2294
perror_plus("scandir");
1220
2296
ret = rmdir(tempdir);
1221
2297
if(ret == -1 and errno != ENOENT){
2298
perror_plus("rmdir");
2303
sigemptyset(&old_sigterm_action.sa_mask);
2304
old_sigterm_action.sa_handler = SIG_DFL;
2305
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2306
&old_sigterm_action,
2309
perror_plus("sigaction");
2312
ret = raise(signal_received);
2313
} while(ret != 0 and errno == EINTR);
2315
perror_plus("raise");
2318
TEMP_FAILURE_RETRY(pause());
1226
2321
return exitcode;