42
42
#include <stddef.h> /* NULL, size_t, ssize_t */
43
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, false, true */
45
#include <stdbool.h> /* bool, true */
46
46
#include <string.h> /* memset(), strcmp(), strlen(),
47
47
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
48
#include <sys/ioctl.h> /* ioctl */
49
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
50
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, uid_t, gid_t, open(),
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
53
54
#include <sys/stat.h> /* open() */
54
55
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
inet_pton(), connect() */
56
struct in6_addr, inet_pton(),
56
58
#include <fcntl.h> /* open() */
57
59
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
64
66
SIOCSIFFLAGS, if_indextoname(),
65
67
if_nametoindex(), IF_NAMESIZE */
66
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
68
#include <netinet/in.h>
69
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
70
getuid(), getgid(), setuid(),
72
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, or, and */
73
#include <iso646.h> /* not, and, or */
74
74
#include <argp.h> /* struct argp_option, error_t, struct
75
75
argp_state, struct argp,
76
76
argp_parse(), ARGP_KEY_ARG,
77
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
78
#include <signal.h> /* sigemptyset(), sigaddset(),
79
sigaction(), SIGTERM, sigaction,
83
79
#include <sys/klog.h> /* klogctl() */
84
#endif /* __linux__ */
87
83
/* All Avahi types, constants and functions
134
130
} mandos_context;
136
/* global context so signal handler can reach it*/
137
mandos_context mc = { .simple_poll = NULL, .server = NULL,
138
.dh_bits = 1024, .priority = "SECURE256"
139
":!CTYPE-X.509:+CTYPE-OPENPGP" };
142
* Make additional room in "buffer" for at least BUFFER_SIZE more
143
* bytes. "buffer_capacity" is how much is currently allocated,
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
134
* "buffer_capacity" is how much is currently allocated,
144
135
* "buffer_length" is how much is already used.
146
size_t incbuffer(char **buffer, size_t buffer_length,
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
147
138
size_t buffer_capacity){
148
139
if(buffer_length + BUFFER_SIZE > buffer_capacity){
149
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
159
150
* Initialize GPGME.
161
static bool init_gpgme(const char *seckey,
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
162
153
const char *pubkey, const char *tempdir){
164
155
gpgme_error_t rc;
188
rc = gpgme_op_import(mc.ctx, pgp_data);
179
rc = gpgme_op_import(mc->ctx, pgp_data);
189
180
if(rc != GPG_ERR_NO_ERROR){
190
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
191
182
gpgme_strsource(rc), gpgme_strerror(rc));
236
227
/* Create new GPGME "context" */
237
rc = gpgme_new(&(mc.ctx));
228
rc = gpgme_new(&(mc->ctx));
238
229
if(rc != GPG_ERR_NO_ERROR){
239
230
fprintf(stderr, "bad gpgme_new: %s: %s\n",
240
231
gpgme_strsource(rc), gpgme_strerror(rc));
252
243
* Decrypt OpenPGP data.
253
244
* Returns -1 on error
255
static ssize_t pgp_packet_decrypt(const char *cryptotext,
246
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
247
const char *cryptotext,
256
248
size_t crypto_size,
257
249
char **plaintext){
258
250
gpgme_data_t dh_crypto, dh_plain;
286
278
/* Decrypt data from the cryptotext data buffer to the plaintext
288
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
280
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
289
281
if(rc != GPG_ERR_NO_ERROR){
290
282
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
291
283
gpgme_strsource(rc), gpgme_strerror(rc));
292
284
plaintext_length = -1;
294
286
gpgme_decrypt_result_t result;
295
result = gpgme_op_decrypt_result(mc.ctx);
287
result = gpgme_op_decrypt_result(mc->ctx);
296
288
if(result == NULL){
297
289
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
335
327
*plaintext = NULL;
337
plaintext_capacity = incbuffer(plaintext,
329
plaintext_capacity = adjustbuffer(plaintext,
338
330
(size_t)plaintext_length,
339
331
plaintext_capacity);
340
332
if(plaintext_capacity == 0){
333
perror("adjustbuffer");
342
334
plaintext_length = -1;
343
335
goto decrypt_end;
390
382
fprintf(stderr, "GnuTLS: %s", string);
393
static int init_gnutls_global(const char *pubkeyfilename,
385
static int init_gnutls_global(mandos_context *mc,
386
const char *pubkeyfilename,
394
387
const char *seckeyfilename){
416
409
/* OpenPGP credentials */
417
gnutls_certificate_allocate_credentials(&mc.cred);
410
gnutls_certificate_allocate_credentials(&mc->cred);
418
411
if(ret != GNUTLS_E_SUCCESS){
419
412
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
423
416
safer_gnutls_strerror(ret));
424
417
gnutls_global_deinit();
434
427
ret = gnutls_certificate_set_openpgp_key_file
435
(mc.cred, pubkeyfilename, seckeyfilename,
428
(mc->cred, pubkeyfilename, seckeyfilename,
436
429
GNUTLS_OPENPGP_FMT_BASE64);
437
430
if(ret != GNUTLS_E_SUCCESS){
446
439
/* GnuTLS server initialization */
447
ret = gnutls_dh_params_init(&mc.dh_params);
440
ret = gnutls_dh_params_init(&mc->dh_params);
448
441
if(ret != GNUTLS_E_SUCCESS){
449
442
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
450
443
" %s\n", safer_gnutls_strerror(ret));
453
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
454
447
if(ret != GNUTLS_E_SUCCESS){
455
448
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
456
449
safer_gnutls_strerror(ret));
460
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
466
gnutls_certificate_free_credentials(mc.cred);
459
gnutls_certificate_free_credentials(mc->cred);
467
460
gnutls_global_deinit();
468
gnutls_dh_params_deinit(mc.dh_params);
461
gnutls_dh_params_deinit(mc->dh_params);
472
static int init_gnutls_session(gnutls_session_t *session){
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
474
468
/* GnuTLS session creation */
475
469
ret = gnutls_init(session, GNUTLS_SERVER);
483
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
477
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
484
478
if(ret != GNUTLS_E_SUCCESS){
485
479
fprintf(stderr, "Syntax error at: %s\n", err);
486
480
fprintf(stderr, "GnuTLS error: %s\n",
493
487
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
495
489
if(ret != GNUTLS_E_SUCCESS){
496
490
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
497
491
safer_gnutls_strerror(ret));
503
497
gnutls_certificate_server_set_request(*session,
504
498
GNUTLS_CERT_IGNORE);
506
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
500
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
515
509
/* Called when a Mandos server is found */
516
510
static int start_mandos_communication(const char *ip, uint16_t port,
517
511
AvahiIfIndex if_index,
522
struct sockaddr_in in;
523
struct sockaddr_in6 in6;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
525
516
char *buffer = NULL;
526
517
char *decrypted_buffer;
527
518
size_t buffer_length = 0;
529
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
532
524
gnutls_session_t session;
533
int pf; /* Protocol family */
543
fprintf(stderr, "Bad address family: %d\n", af);
547
ret = init_gnutls_session(&session);
526
ret = init_gnutls_session(mc, &session);
553
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
557
tcp_sd = socket(pf, SOCK_STREAM, 0);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
559
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);
563
550
memset(&to, 0, sizeof(to));
565
to.in6.sin6_family = (uint16_t)af;
566
ret = inet_pton(af, ip, &to.in6.sin6_addr);
568
to.in.sin_family = (sa_family_t)af;
569
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);
572
556
perror("inet_pton");
576
560
fprintf(stderr, "Bad address: %s\n", ip);
580
to.in6.sin6_port = htons(port); /* Spurious warnings from
582
-Wunreachable-code */
584
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
585
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
587
if(if_index == AVAHI_IF_UNSPEC){
588
fprintf(stderr, "An IPv6 link-local address is incomplete"
589
" without a network interface\n");
592
/* Set the network interface number as scope */
593
to.in6.sin6_scope_id = (uint32_t)if_index;
596
to.in.sin_port = htons(port); /* Spurious warnings from
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
598
565
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
602
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
603
char interface[IF_NAMESIZE];
604
if(if_indextoname((unsigned int)if_index, interface) == NULL){
605
perror("if_indextoname");
607
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
608
ip, interface, port);
611
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
614
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
615
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
618
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
621
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){
625
575
perror("inet_ntop");
627
577
if(strcmp(addrstr, ip) != 0){
634
ret = connect(tcp_sd, &to.in6, sizeof(to));
636
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
583
ret = connect(tcp_sd, &to.in, sizeof(to));
639
585
perror("connect");
686
632
/* Read OpenPGP packet that contains the wanted password */
689
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
635
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
694
buffer_capacity = incbuffer(&buffer, buffer_length,
640
buffer_capacity = adjustbuffer(&buffer, buffer_length,
695
641
buffer_capacity);
696
642
if(buffer_capacity == 0){
643
perror("adjustbuffer");
739
685
gnutls_bye(session, GNUTLS_SHUT_RDWR);
741
687
if(buffer_length > 0){
742
decrypted_buffer_size = pgp_packet_decrypt(buffer,
688
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
744
690
&decrypted_buffer);
745
691
if(decrypted_buffer_size >= 0){
791
737
AVAHI_GCC_UNUSED AvahiStringList *txt,
792
738
AVAHI_GCC_UNUSED AvahiLookupResultFlags
794
AVAHI_GCC_UNUSED void* userdata){
741
mandos_context *mc = userdata;
797
744
/* Called whenever a service has been resolved successfully or
802
749
case AVAHI_RESOLVER_FAILURE:
803
750
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
804
751
" of type '%s' in domain '%s': %s\n", name, type, domain,
805
avahi_strerror(avahi_server_errno(mc.server)));
752
avahi_strerror(avahi_server_errno(mc->server)));
808
755
case AVAHI_RESOLVER_FOUND:
814
761
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
815
762
ip, (intmax_t)interface, port);
817
int ret = start_mandos_communication(ip, port, interface,
818
avahi_proto_to_af(proto));
764
int ret = start_mandos_communication(ip, port, interface, mc);
820
avahi_simple_poll_quit(mc.simple_poll);
766
avahi_simple_poll_quit(mc->simple_poll);
844
791
case AVAHI_BROWSER_FAILURE:
846
793
fprintf(stderr, "(Avahi browser) %s\n",
847
avahi_strerror(avahi_server_errno(mc.server)));
848
avahi_simple_poll_quit(mc.simple_poll);
794
avahi_strerror(avahi_server_errno(mc->server)));
795
avahi_simple_poll_quit(mc->simple_poll);
851
798
case AVAHI_BROWSER_NEW:
854
801
the callback function is called the Avahi server will free the
855
802
resolver for us. */
857
if(!(avahi_s_service_resolver_new(mc.server, interface,
804
if(!(avahi_s_service_resolver_new(mc->server, interface,
858
805
protocol, name, type, domain,
859
806
AVAHI_PROTO_INET6, 0,
860
resolve_callback, NULL)))
807
resolve_callback, mc)))
861
808
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
862
name, avahi_strerror(avahi_server_errno(mc.server)));
809
name, avahi_strerror(avahi_server_errno(mc->server)));
865
812
case AVAHI_BROWSER_REMOVE:
877
sig_atomic_t quit_now = 0;
879
/* stop main loop after sigterm has been called */
880
static void handle_sigterm(__attribute__((unused)) int sig){
885
int old_errno = errno;
886
if(mc.simple_poll != NULL){
887
avahi_simple_poll_quit(mc.simple_poll);
892
824
int main(int argc, char *argv[]){
893
825
AvahiSServiceBrowser *sb = NULL;
908
840
const char *seckey = PATHDIR "/" SECKEY;
909
841
const char *pubkey = PATHDIR "/" PUBKEY;
911
/* Initialize Mandos context */
912
mc = (mandos_context){ .simple_poll = NULL, .server = NULL,
913
.dh_bits = 1024, .priority = "SECURE256"
914
":!CTYPE-X.509:+CTYPE-OPENPGP" };
843
mandos_context mc = { .simple_poll = NULL, .server = NULL,
844
.dh_bits = 1024, .priority = "SECURE256"
845
":!CTYPE-X.509:+CTYPE-OPENPGP" };
915
846
bool gnutls_initialized = false;
916
847
bool gpgme_initialized = false;
917
848
double delay = 2.5;
919
struct sigaction old_sigterm_action;
920
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
923
851
struct argp_option options[] = {
930
858
{ .name = "interface", .key = 'i',
932
.doc = "Network interface that will be used to search for"
860
.doc = "Interface that will be used to search for Mandos"
935
863
{ .name = "seckey", .key = 's',
1019
avahi_set_log_function(empty_log);
1022
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1023
from the signal handler */
1024
/* Initialize the pseudo-RNG for Avahi */
1025
srand((unsigned int) time(NULL));
1026
mc.simple_poll = avahi_simple_poll_new();
1027
if(mc.simple_poll == NULL){
1028
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1029
exitcode = EXIT_FAILURE;
1033
sigemptyset(&sigterm_action.sa_mask);
1034
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1036
perror("sigaddset");
1037
exitcode = EXIT_FAILURE;
1040
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1042
perror("sigaddset");
1043
exitcode = EXIT_FAILURE;
1046
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1048
perror("sigaddset");
1049
exitcode = EXIT_FAILURE;
1052
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1054
perror("sigaction");
1055
exitcode = EXIT_FAILURE;
1059
946
/* If the interface is down, bring it up */
1060
if(interface[0] != '\0'){
1061
948
#ifdef __linux__
1062
949
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1063
950
messages to mess up the prompt */
1064
951
ret = klogctl(8, NULL, 5);
1065
bool restore_loglevel = true;
1067
restore_loglevel = false;
1068
953
perror("klogctl");
1070
#endif /* __linux__ */
1072
957
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1074
959
perror("socket");
1075
960
exitcode = EXIT_FAILURE;
1076
961
#ifdef __linux__
1077
if(restore_loglevel){
1078
ret = klogctl(7, NULL, 0);
962
ret = klogctl(7, NULL, 0);
1083
#endif /* __linux__ */
1086
969
strcpy(network.ifr_name, interface);
1089
972
perror("ioctl SIOCGIFFLAGS");
1090
973
#ifdef __linux__
1091
if(restore_loglevel){
1092
ret = klogctl(7, NULL, 0);
974
ret = klogctl(7, NULL, 0);
1097
#endif /* __linux__ */
1098
979
exitcode = EXIT_FAILURE;
1105
986
perror("ioctl SIOCSIFFLAGS");
1106
987
exitcode = EXIT_FAILURE;
1107
988
#ifdef __linux__
1108
if(restore_loglevel){
1109
ret = klogctl(7, NULL, 0);
989
ret = klogctl(7, NULL, 0);
1114
#endif /* __linux__ */
1134
1013
perror("close");
1136
1015
#ifdef __linux__
1137
if(restore_loglevel){
1138
/* Restores kernel loglevel to default */
1139
ret = klogctl(7, NULL, 0);
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
1144
#endif /* __linux__ */
1147
1024
uid = getuid();
1148
1025
gid = getgid();
1153
1029
perror("setgid");
1158
1034
perror("setuid");
1161
ret = init_gnutls_global(pubkey, seckey);
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1163
1039
fprintf(stderr, "init_gnutls_global failed\n");
1164
1040
exitcode = EXIT_FAILURE;
1174
1050
tempdir_created = true;
1176
if(not init_gpgme(pubkey, seckey, tempdir)){
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1177
1053
fprintf(stderr, "init_gpgme failed\n");
1178
1054
exitcode = EXIT_FAILURE;
1181
1057
gpgme_initialized = true;
1184
if(interface[0] != '\0'){
1185
if_index = (AvahiIfIndex) if_nametoindex(interface);
1187
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1188
exitcode = EXIT_FAILURE;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;
1193
1067
if(connect_to != NULL){
1210
1084
port = (uint16_t)tmpmax;
1211
1085
*address = '\0';
1212
1086
address = connect_to;
1213
/* Colon in address indicates IPv6 */
1215
if(strchr(address, ':') != NULL){
1220
ret = start_mandos_communication(address, port, if_index, af);
1087
ret = start_mandos_communication(address, port, if_index, &mc);
1222
1089
exitcode = EXIT_FAILURE;
1097
avahi_set_log_function(empty_log);
1100
/* Initialize the pseudo-RNG for Avahi */
1101
srand((unsigned int) time(NULL));
1103
/* Allocate main Avahi loop object */
1104
mc.simple_poll = avahi_simple_poll_new();
1105
if(mc.simple_poll == NULL){
1106
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1107
exitcode = EXIT_FAILURE;
1230
1112
AvahiServerConfig config;
1231
1113
/* Do not publish any local Zeroconf records */
1255
1137
/* Create the Avahi service browser */
1256
1138
sb = avahi_s_service_browser_new(mc.server, if_index,
1257
1139
AVAHI_PROTO_INET6, "_mandos._tcp",
1258
NULL, 0, browse_callback, NULL);
1140
NULL, 0, browse_callback, &mc);
1259
1141
if(sb == NULL){
1260
1142
fprintf(stderr, "Failed to create service browser: %s\n",
1261
1143
avahi_strerror(avahi_server_errno(mc.server)));