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*/
140
* Make additional room in "buffer" for at least BUFFER_SIZE more
141
* 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,
142
135
* "buffer_length" is how much is already used.
144
size_t incbuffer(char **buffer, size_t buffer_length,
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
145
138
size_t buffer_capacity){
146
139
if(buffer_length + BUFFER_SIZE > buffer_capacity){
147
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
157
150
* Initialize GPGME.
159
static bool init_gpgme(const char *seckey,
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
160
153
const char *pubkey, const char *tempdir){
162
155
gpgme_error_t rc;
186
rc = gpgme_op_import(mc.ctx, pgp_data);
179
rc = gpgme_op_import(mc->ctx, pgp_data);
187
180
if(rc != GPG_ERR_NO_ERROR){
188
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
189
182
gpgme_strsource(rc), gpgme_strerror(rc));
234
227
/* Create new GPGME "context" */
235
rc = gpgme_new(&(mc.ctx));
228
rc = gpgme_new(&(mc->ctx));
236
229
if(rc != GPG_ERR_NO_ERROR){
237
230
fprintf(stderr, "bad gpgme_new: %s: %s\n",
238
231
gpgme_strsource(rc), gpgme_strerror(rc));
250
243
* Decrypt OpenPGP data.
251
244
* Returns -1 on error
253
static ssize_t pgp_packet_decrypt(const char *cryptotext,
246
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
247
const char *cryptotext,
254
248
size_t crypto_size,
255
249
char **plaintext){
256
250
gpgme_data_t dh_crypto, dh_plain;
284
278
/* Decrypt data from the cryptotext data buffer to the plaintext
286
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
280
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
287
281
if(rc != GPG_ERR_NO_ERROR){
288
282
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
289
283
gpgme_strsource(rc), gpgme_strerror(rc));
290
284
plaintext_length = -1;
292
286
gpgme_decrypt_result_t result;
293
result = gpgme_op_decrypt_result(mc.ctx);
287
result = gpgme_op_decrypt_result(mc->ctx);
294
288
if(result == NULL){
295
289
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
333
327
*plaintext = NULL;
335
plaintext_capacity = incbuffer(plaintext,
329
plaintext_capacity = adjustbuffer(plaintext,
336
330
(size_t)plaintext_length,
337
331
plaintext_capacity);
338
332
if(plaintext_capacity == 0){
333
perror("adjustbuffer");
340
334
plaintext_length = -1;
341
335
goto decrypt_end;
388
382
fprintf(stderr, "GnuTLS: %s", string);
391
static int init_gnutls_global(const char *pubkeyfilename,
385
static int init_gnutls_global(mandos_context *mc,
386
const char *pubkeyfilename,
392
387
const char *seckeyfilename){
414
409
/* OpenPGP credentials */
415
gnutls_certificate_allocate_credentials(&mc.cred);
410
gnutls_certificate_allocate_credentials(&mc->cred);
416
411
if(ret != GNUTLS_E_SUCCESS){
417
412
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
421
416
safer_gnutls_strerror(ret));
422
417
gnutls_global_deinit();
432
427
ret = gnutls_certificate_set_openpgp_key_file
433
(mc.cred, pubkeyfilename, seckeyfilename,
428
(mc->cred, pubkeyfilename, seckeyfilename,
434
429
GNUTLS_OPENPGP_FMT_BASE64);
435
430
if(ret != GNUTLS_E_SUCCESS){
444
439
/* GnuTLS server initialization */
445
ret = gnutls_dh_params_init(&mc.dh_params);
440
ret = gnutls_dh_params_init(&mc->dh_params);
446
441
if(ret != GNUTLS_E_SUCCESS){
447
442
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
448
443
" %s\n", safer_gnutls_strerror(ret));
451
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
452
447
if(ret != GNUTLS_E_SUCCESS){
453
448
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
454
449
safer_gnutls_strerror(ret));
458
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
464
gnutls_certificate_free_credentials(mc.cred);
459
gnutls_certificate_free_credentials(mc->cred);
465
460
gnutls_global_deinit();
466
gnutls_dh_params_deinit(mc.dh_params);
461
gnutls_dh_params_deinit(mc->dh_params);
470
static int init_gnutls_session(gnutls_session_t *session){
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
472
468
/* GnuTLS session creation */
473
469
ret = gnutls_init(session, GNUTLS_SERVER);
481
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
477
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
482
478
if(ret != GNUTLS_E_SUCCESS){
483
479
fprintf(stderr, "Syntax error at: %s\n", err);
484
480
fprintf(stderr, "GnuTLS error: %s\n",
491
487
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
493
489
if(ret != GNUTLS_E_SUCCESS){
494
490
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
495
491
safer_gnutls_strerror(ret));
501
497
gnutls_certificate_server_set_request(*session,
502
498
GNUTLS_CERT_IGNORE);
504
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
500
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
513
509
/* Called when a Mandos server is found */
514
510
static int start_mandos_communication(const char *ip, uint16_t port,
515
511
AvahiIfIndex if_index,
520
struct sockaddr_in in;
521
struct sockaddr_in6 in6;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
523
516
char *buffer = NULL;
524
517
char *decrypted_buffer;
525
518
size_t buffer_length = 0;
527
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
530
524
gnutls_session_t session;
531
int pf; /* Protocol family */
541
fprintf(stderr, "Bad address family: %d\n", af);
545
ret = init_gnutls_session(&session);
526
ret = init_gnutls_session(mc, &session);
551
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
555
tcp_sd = socket(pf, SOCK_STREAM, 0);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
557
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);
561
550
memset(&to, 0, sizeof(to));
563
to.in6.sin6_family = (uint16_t)af;
564
ret = inet_pton(af, ip, &to.in6.sin6_addr);
566
to.in.sin_family = (sa_family_t)af;
567
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);
570
556
perror("inet_pton");
574
560
fprintf(stderr, "Bad address: %s\n", ip);
578
to.in6.sin6_port = htons(port); /* Spurious warnings from
580
-Wunreachable-code */
582
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
583
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
585
if(if_index == AVAHI_IF_UNSPEC){
586
fprintf(stderr, "An IPv6 link-local address is incomplete"
587
" without a network interface\n");
590
/* Set the network interface number as scope */
591
to.in6.sin6_scope_id = (uint32_t)if_index;
594
to.in.sin_port = htons(port); /* Spurious warnings from
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
596
565
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
600
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
601
char interface[IF_NAMESIZE];
602
if(if_indextoname((unsigned int)if_index, interface) == NULL){
603
perror("if_indextoname");
605
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
606
ip, interface, port);
609
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
612
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
613
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
616
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
619
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){
623
575
perror("inet_ntop");
625
577
if(strcmp(addrstr, ip) != 0){
632
ret = connect(tcp_sd, &to.in6, sizeof(to));
634
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
583
ret = connect(tcp_sd, &to.in, sizeof(to));
637
585
perror("connect");
684
632
/* Read OpenPGP packet that contains the wanted password */
687
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
635
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
692
buffer_capacity = incbuffer(&buffer, buffer_length,
640
buffer_capacity = adjustbuffer(&buffer, buffer_length,
693
641
buffer_capacity);
694
642
if(buffer_capacity == 0){
643
perror("adjustbuffer");
737
685
gnutls_bye(session, GNUTLS_SHUT_RDWR);
739
687
if(buffer_length > 0){
740
decrypted_buffer_size = pgp_packet_decrypt(buffer,
688
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
742
690
&decrypted_buffer);
743
691
if(decrypted_buffer_size >= 0){
789
737
AVAHI_GCC_UNUSED AvahiStringList *txt,
790
738
AVAHI_GCC_UNUSED AvahiLookupResultFlags
792
AVAHI_GCC_UNUSED void* userdata){
741
mandos_context *mc = userdata;
795
744
/* Called whenever a service has been resolved successfully or
800
749
case AVAHI_RESOLVER_FAILURE:
801
750
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
802
751
" of type '%s' in domain '%s': %s\n", name, type, domain,
803
avahi_strerror(avahi_server_errno(mc.server)));
752
avahi_strerror(avahi_server_errno(mc->server)));
806
755
case AVAHI_RESOLVER_FOUND:
812
761
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
813
762
ip, (intmax_t)interface, port);
815
int ret = start_mandos_communication(ip, port, interface,
816
avahi_proto_to_af(proto));
764
int ret = start_mandos_communication(ip, port, interface, mc);
818
avahi_simple_poll_quit(mc.simple_poll);
766
avahi_simple_poll_quit(mc->simple_poll);
842
791
case AVAHI_BROWSER_FAILURE:
844
793
fprintf(stderr, "(Avahi browser) %s\n",
845
avahi_strerror(avahi_server_errno(mc.server)));
846
avahi_simple_poll_quit(mc.simple_poll);
794
avahi_strerror(avahi_server_errno(mc->server)));
795
avahi_simple_poll_quit(mc->simple_poll);
849
798
case AVAHI_BROWSER_NEW:
852
801
the callback function is called the Avahi server will free the
853
802
resolver for us. */
855
if(!(avahi_s_service_resolver_new(mc.server, interface,
804
if(!(avahi_s_service_resolver_new(mc->server, interface,
856
805
protocol, name, type, domain,
857
806
AVAHI_PROTO_INET6, 0,
858
resolve_callback, NULL)))
807
resolve_callback, mc)))
859
808
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
860
name, avahi_strerror(avahi_server_errno(mc.server)));
809
name, avahi_strerror(avahi_server_errno(mc->server)));
863
812
case AVAHI_BROWSER_REMOVE:
875
sig_atomic_t quit_now = 0;
877
static void handle_sigterm(__attribute__((unused)) int sig){
882
int old_errno = errno;
883
if(mc.simple_poll != NULL){
884
avahi_simple_poll_quit(mc.simple_poll);
889
824
int main(int argc, char *argv[]){
890
825
AvahiSServiceBrowser *sb = NULL;
905
840
const char *seckey = PATHDIR "/" SECKEY;
906
841
const char *pubkey = PATHDIR "/" PUBKEY;
908
/* Initialize Mandos context */
909
mc = (mandos_context){ .simple_poll = NULL, .server = NULL,
910
.dh_bits = 1024, .priority = "SECURE256"
911
":!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" };
912
846
bool gnutls_initialized = false;
913
847
bool gpgme_initialized = false;
914
848
double delay = 2.5;
916
struct sigaction old_sigterm_action;
917
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
920
851
struct argp_option options[] = {
927
858
{ .name = "interface", .key = 'i',
929
.doc = "Network interface that will be used to search for"
860
.doc = "Interface that will be used to search for Mandos"
932
863
{ .name = "seckey", .key = 's',
1015
946
/* If the interface is down, bring it up */
1016
if(interface[0] != '\0'){
1017
948
#ifdef __linux__
1018
949
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1019
950
messages to mess up the prompt */
1020
951
ret = klogctl(8, NULL, 5);
1021
bool restore_loglevel = true;
1023
restore_loglevel = false;
1024
953
perror("klogctl");
1026
#endif /* __linux__ */
1028
957
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1030
959
perror("socket");
1031
960
exitcode = EXIT_FAILURE;
1032
961
#ifdef __linux__
1033
if(restore_loglevel){
1034
ret = klogctl(7, NULL, 0);
962
ret = klogctl(7, NULL, 0);
1039
#endif /* __linux__ */
1042
969
strcpy(network.ifr_name, interface);
1045
972
perror("ioctl SIOCGIFFLAGS");
1046
973
#ifdef __linux__
1047
if(restore_loglevel){
1048
ret = klogctl(7, NULL, 0);
974
ret = klogctl(7, NULL, 0);
1053
#endif /* __linux__ */
1054
979
exitcode = EXIT_FAILURE;
1061
986
perror("ioctl SIOCSIFFLAGS");
1062
987
exitcode = EXIT_FAILURE;
1063
988
#ifdef __linux__
1064
if(restore_loglevel){
1065
ret = klogctl(7, NULL, 0);
989
ret = klogctl(7, NULL, 0);
1070
#endif /* __linux__ */
1090
1013
perror("close");
1092
1015
#ifdef __linux__
1093
if(restore_loglevel){
1094
/* Restores kernel loglevel to default */
1095
ret = klogctl(7, NULL, 0);
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
1100
#endif /* __linux__ */
1103
1024
uid = getuid();
1104
1025
gid = getgid();
1109
1029
perror("setgid");
1114
1034
perror("setuid");
1117
ret = init_gnutls_global(pubkey, seckey);
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1119
1039
fprintf(stderr, "init_gnutls_global failed\n");
1120
1040
exitcode = EXIT_FAILURE;
1130
1050
tempdir_created = true;
1132
if(not init_gpgme(pubkey, seckey, tempdir)){
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1133
1053
fprintf(stderr, "init_gpgme failed\n");
1134
1054
exitcode = EXIT_FAILURE;
1137
1057
gpgme_initialized = true;
1140
if(interface[0] != '\0'){
1141
if_index = (AvahiIfIndex) if_nametoindex(interface);
1143
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1144
exitcode = EXIT_FAILURE;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;
1149
1067
if(connect_to != NULL){
1166
1084
port = (uint16_t)tmpmax;
1167
1085
*address = '\0';
1168
1086
address = connect_to;
1169
/* Colon in address indicates IPv6 */
1171
if(strchr(address, ':') != NULL){
1176
ret = start_mandos_communication(address, port, if_index, af);
1087
ret = start_mandos_communication(address, port, if_index, &mc);
1178
1089
exitcode = EXIT_FAILURE;
1226
1137
/* Create the Avahi service browser */
1227
1138
sb = avahi_s_service_browser_new(mc.server, if_index,
1228
1139
AVAHI_PROTO_INET6, "_mandos._tcp",
1229
NULL, 0, browse_callback, NULL);
1140
NULL, 0, browse_callback, &mc);
1230
1141
if(sb == NULL){
1231
1142
fprintf(stderr, "Failed to create service browser: %s\n",
1232
1143
avahi_strerror(avahi_server_errno(mc.server)));
1237
sigemptyset(&sigterm_action.sa_mask);
1238
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1240
perror("sigaddset");
1241
exitcode = EXIT_FAILURE;
1244
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1246
perror("sigaddset");
1247
exitcode = EXIT_FAILURE;
1250
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1252
perror("sigaddset");
1253
exitcode = EXIT_FAILURE;
1256
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1258
perror("sigaction");
1259
exitcode = EXIT_FAILURE;
1263
1148
/* Run the main loop */