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, true */
45
#include <stdbool.h> /* bool, false, 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, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
51
SOCK_STREAM, uid_t, gid_t, open(),
54
53
#include <sys/stat.h> /* open() */
55
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
56
struct in6_addr, inet_pton(),
55
inet_pton(), connect() */
58
56
#include <fcntl.h> /* open() */
59
57
#include <dirent.h> /* opendir(), struct dirent, readdir()
65
63
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
66
64
SIOCSIFFLAGS, if_indextoname(),
67
65
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
66
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
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, and, or */
73
#include <iso646.h> /* not, or, and */
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 */
79
82
#include <sys/klog.h> /* klogctl() */
130
133
} mandos_context;
135
/* global context so signal handler can reach it*/
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
134
* "buffer_capacity" is how much is currently allocated,
135
* "buffer_length" is how much is already used.
139
* Make additional room in "buffer" for at least BUFFER_SIZE
140
* additional bytes. "buffer_capacity" is how much is currently
141
* allocated, "buffer_length" is how much is already used.
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
143
size_t incbuffer(char **buffer, size_t buffer_length,
138
144
size_t buffer_capacity){
139
145
if(buffer_length + BUFFER_SIZE > buffer_capacity){
140
146
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
150
156
* Initialize GPGME.
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
158
static bool init_gpgme(const char *seckey,
153
159
const char *pubkey, const char *tempdir){
155
161
gpgme_error_t rc;
179
rc = gpgme_op_import(mc->ctx, pgp_data);
185
rc = gpgme_op_import(mc.ctx, pgp_data);
180
186
if(rc != GPG_ERR_NO_ERROR){
181
187
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
188
gpgme_strsource(rc), gpgme_strerror(rc));
227
233
/* Create new GPGME "context" */
228
rc = gpgme_new(&(mc->ctx));
234
rc = gpgme_new(&(mc.ctx));
229
235
if(rc != GPG_ERR_NO_ERROR){
230
236
fprintf(stderr, "bad gpgme_new: %s: %s\n",
231
237
gpgme_strsource(rc), gpgme_strerror(rc));
243
249
* Decrypt OpenPGP data.
244
250
* Returns -1 on error
246
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
247
const char *cryptotext,
252
static ssize_t pgp_packet_decrypt(const char *cryptotext,
248
253
size_t crypto_size,
249
254
char **plaintext){
250
255
gpgme_data_t dh_crypto, dh_plain;
278
283
/* Decrypt data from the cryptotext data buffer to the plaintext
280
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
285
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
281
286
if(rc != GPG_ERR_NO_ERROR){
282
287
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
283
288
gpgme_strsource(rc), gpgme_strerror(rc));
284
289
plaintext_length = -1;
286
291
gpgme_decrypt_result_t result;
287
result = gpgme_op_decrypt_result(mc->ctx);
292
result = gpgme_op_decrypt_result(mc.ctx);
288
293
if(result == NULL){
289
294
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
327
332
*plaintext = NULL;
329
plaintext_capacity = adjustbuffer(plaintext,
334
plaintext_capacity = incbuffer(plaintext,
330
335
(size_t)plaintext_length,
331
336
plaintext_capacity);
332
337
if(plaintext_capacity == 0){
333
perror("adjustbuffer");
334
339
plaintext_length = -1;
335
340
goto decrypt_end;
382
387
fprintf(stderr, "GnuTLS: %s", string);
385
static int init_gnutls_global(mandos_context *mc,
386
const char *pubkeyfilename,
390
static int init_gnutls_global(const char *pubkeyfilename,
387
391
const char *seckeyfilename){
409
413
/* OpenPGP credentials */
410
gnutls_certificate_allocate_credentials(&mc->cred);
414
gnutls_certificate_allocate_credentials(&mc.cred);
411
415
if(ret != GNUTLS_E_SUCCESS){
412
416
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
416
420
safer_gnutls_strerror(ret));
417
421
gnutls_global_deinit();
427
431
ret = gnutls_certificate_set_openpgp_key_file
428
(mc->cred, pubkeyfilename, seckeyfilename,
432
(mc.cred, pubkeyfilename, seckeyfilename,
429
433
GNUTLS_OPENPGP_FMT_BASE64);
430
434
if(ret != GNUTLS_E_SUCCESS){
439
443
/* GnuTLS server initialization */
440
ret = gnutls_dh_params_init(&mc->dh_params);
444
ret = gnutls_dh_params_init(&mc.dh_params);
441
445
if(ret != GNUTLS_E_SUCCESS){
442
446
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
443
447
" %s\n", safer_gnutls_strerror(ret));
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
450
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
447
451
if(ret != GNUTLS_E_SUCCESS){
448
452
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
449
453
safer_gnutls_strerror(ret));
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
457
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
459
gnutls_certificate_free_credentials(mc->cred);
463
gnutls_certificate_free_credentials(mc.cred);
460
464
gnutls_global_deinit();
461
gnutls_dh_params_deinit(mc->dh_params);
465
gnutls_dh_params_deinit(mc.dh_params);
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
469
static int init_gnutls_session(gnutls_session_t *session){
468
471
/* GnuTLS session creation */
469
472
ret = gnutls_init(session, GNUTLS_SERVER);
477
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
480
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
478
481
if(ret != GNUTLS_E_SUCCESS){
479
482
fprintf(stderr, "Syntax error at: %s\n", err);
480
483
fprintf(stderr, "GnuTLS error: %s\n",
487
490
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
489
492
if(ret != GNUTLS_E_SUCCESS){
490
493
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
491
494
safer_gnutls_strerror(ret));
497
500
gnutls_certificate_server_set_request(*session,
498
501
GNUTLS_CERT_IGNORE);
500
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
503
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
509
512
/* Called when a Mandos server is found */
510
513
static int start_mandos_communication(const char *ip, uint16_t port,
511
514
AvahiIfIndex if_index,
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
519
struct sockaddr_in in;
520
struct sockaddr_in6 in6;
516
522
char *buffer = NULL;
517
523
char *decrypted_buffer;
518
524
size_t buffer_length = 0;
520
526
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
524
529
gnutls_session_t session;
526
ret = init_gnutls_session(mc, &session);
530
int pf; /* Protocol family */
540
fprintf(stderr, "Bad address family: %d\n", af);
544
ret = init_gnutls_session(&session);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
550
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
554
tcp_sd = socket(pf, SOCK_STREAM, 0);
538
556
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);
550
560
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);
562
to.in6.sin6_family = (uint16_t)af;
563
ret = inet_pton(af, ip, &to.in6.sin6_addr);
565
to.in.sin_family = (sa_family_t)af;
566
ret = inet_pton(af, ip, &to.in.sin_addr);
556
569
perror("inet_pton");
560
573
fprintf(stderr, "Bad address: %s\n", ip);
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
577
to.in6.sin6_port = htons(port); /* Spurious warnings from
579
-Wunreachable-code */
581
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
582
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
584
if(if_index == AVAHI_IF_UNSPEC){
585
fprintf(stderr, "An IPv6 link-local address is incomplete"
586
" without a network interface\n");
589
/* Set the network interface number as scope */
590
to.in6.sin6_scope_id = (uint32_t)if_index;
593
to.in.sin_port = htons(port); /* Spurious warnings from
565
595
-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){
599
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
600
char interface[IF_NAMESIZE];
601
if(if_indextoname((unsigned int)if_index, interface) == NULL){
602
perror("if_indextoname");
604
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
605
ip, interface, port);
608
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
611
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
612
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
615
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
618
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
575
622
perror("inet_ntop");
577
624
if(strcmp(addrstr, ip) != 0){
583
ret = connect(tcp_sd, &to.in, sizeof(to));
631
ret = connect(tcp_sd, &to.in6, sizeof(to));
633
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
585
636
perror("connect");
632
683
/* Read OpenPGP packet that contains the wanted password */
635
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
686
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
640
buffer_capacity = adjustbuffer(&buffer, buffer_length,
691
buffer_capacity = incbuffer(&buffer, buffer_length,
641
692
buffer_capacity);
642
693
if(buffer_capacity == 0){
643
perror("adjustbuffer");
685
736
gnutls_bye(session, GNUTLS_SHUT_RDWR);
687
738
if(buffer_length > 0){
688
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
739
decrypted_buffer_size = pgp_packet_decrypt(buffer,
690
741
&decrypted_buffer);
691
742
if(decrypted_buffer_size >= 0){
737
788
AVAHI_GCC_UNUSED AvahiStringList *txt,
738
789
AVAHI_GCC_UNUSED AvahiLookupResultFlags
741
mandos_context *mc = userdata;
791
AVAHI_GCC_UNUSED void* userdata){
744
794
/* Called whenever a service has been resolved successfully or
749
799
case AVAHI_RESOLVER_FAILURE:
750
800
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
751
801
" of type '%s' in domain '%s': %s\n", name, type, domain,
752
avahi_strerror(avahi_server_errno(mc->server)));
802
avahi_strerror(avahi_server_errno(mc.server)));
755
805
case AVAHI_RESOLVER_FOUND:
761
811
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
762
812
ip, (intmax_t)interface, port);
764
int ret = start_mandos_communication(ip, port, interface, mc);
814
int ret = start_mandos_communication(ip, port, interface,
815
avahi_proto_to_af(proto));
766
avahi_simple_poll_quit(mc->simple_poll);
817
avahi_simple_poll_quit(mc.simple_poll);
791
841
case AVAHI_BROWSER_FAILURE:
793
843
fprintf(stderr, "(Avahi browser) %s\n",
794
avahi_strerror(avahi_server_errno(mc->server)));
795
avahi_simple_poll_quit(mc->simple_poll);
844
avahi_strerror(avahi_server_errno(mc.server)));
845
avahi_simple_poll_quit(mc.simple_poll);
798
848
case AVAHI_BROWSER_NEW:
801
851
the callback function is called the Avahi server will free the
802
852
resolver for us. */
804
if(!(avahi_s_service_resolver_new(mc->server, interface,
854
if(!(avahi_s_service_resolver_new(mc.server, interface,
805
855
protocol, name, type, domain,
806
856
AVAHI_PROTO_INET6, 0,
807
resolve_callback, mc)))
857
resolve_callback, NULL)))
808
858
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
809
name, avahi_strerror(avahi_server_errno(mc->server)));
859
name, avahi_strerror(avahi_server_errno(mc.server)));
812
862
case AVAHI_BROWSER_REMOVE:
874
static void handle_sigterm(__attribute__((unused)) int sig){
875
int old_errno = errno;
876
avahi_simple_poll_quit(mc.simple_poll);
824
880
int main(int argc, char *argv[]){
825
881
AvahiSServiceBrowser *sb = NULL;
840
896
const char *seckey = PATHDIR "/" SECKEY;
841
897
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" };
899
/* Initialize Mandos context */
900
mc = (mandos_context){ .simple_poll = NULL, .server = NULL,
901
.dh_bits = 1024, .priority = "SECURE256"
902
":!CTYPE-X.509:+CTYPE-OPENPGP" };
846
903
bool gnutls_initialized = false;
847
904
bool gpgme_initialized = false;
848
905
double delay = 2.5;
907
struct sigaction old_sigterm_action;
908
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
851
911
struct argp_option options[] = {
858
918
{ .name = "interface", .key = 'i',
860
.doc = "Interface that will be used to search for Mandos"
920
.doc = "Network interface that will be used to search for"
863
923
{ .name = "seckey", .key = 's',
946
1006
/* If the interface is down, bring it up */
1007
if(interface[0] != '\0'){
948
1008
#ifdef __linux__
949
1009
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
950
1010
messages to mess up the prompt */
951
1011
ret = klogctl(8, NULL, 5);
1012
bool restore_loglevel = true;
1014
restore_loglevel = false;
953
1015
perror("klogctl");
972
1036
perror("ioctl SIOCGIFFLAGS");
973
1037
#ifdef __linux__
974
ret = klogctl(7, NULL, 0);
1038
if(restore_loglevel){
1039
ret = klogctl(7, NULL, 0);
979
1045
exitcode = EXIT_FAILURE;
986
1052
perror("ioctl SIOCSIFFLAGS");
987
1053
exitcode = EXIT_FAILURE;
988
1054
#ifdef __linux__
989
ret = klogctl(7, NULL, 0);
1055
if(restore_loglevel){
1056
ret = klogctl(7, NULL, 0);
1013
1081
perror("close");
1015
1083
#ifdef __linux__
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
1084
if(restore_loglevel){
1085
/* Restores kernel loglevel to default */
1086
ret = klogctl(7, NULL, 0);
1034
1105
perror("setuid");
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1108
ret = init_gnutls_global(pubkey, seckey);
1039
1110
fprintf(stderr, "init_gnutls_global failed\n");
1040
1111
exitcode = EXIT_FAILURE;
1050
1121
tempdir_created = true;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1123
if(not init_gpgme(pubkey, seckey, tempdir)){
1053
1124
fprintf(stderr, "init_gpgme failed\n");
1054
1125
exitcode = EXIT_FAILURE;
1057
1128
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;
1131
if(interface[0] != '\0'){
1132
if_index = (AvahiIfIndex) if_nametoindex(interface);
1134
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1135
exitcode = EXIT_FAILURE;
1067
1140
if(connect_to != NULL){
1084
1157
port = (uint16_t)tmpmax;
1085
1158
*address = '\0';
1086
1159
address = connect_to;
1087
ret = start_mandos_communication(address, port, if_index, &mc);
1160
/* Colon in address indicates IPv6 */
1162
if(strchr(address, ':') != NULL){
1167
ret = start_mandos_communication(address, port, if_index, af);
1089
1169
exitcode = EXIT_FAILURE;
1137
1217
/* Create the Avahi service browser */
1138
1218
sb = avahi_s_service_browser_new(mc.server, if_index,
1139
1219
AVAHI_PROTO_INET6, "_mandos._tcp",
1140
NULL, 0, browse_callback, &mc);
1220
NULL, 0, browse_callback, NULL);
1141
1221
if(sb == NULL){
1142
1222
fprintf(stderr, "Failed to create service browser: %s\n",
1143
1223
avahi_strerror(avahi_server_errno(mc.server)));
1228
sigemptyset(&sigterm_action.sa_mask);
1229
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1231
perror("sigaddset");
1232
exitcode = EXIT_FAILURE;
1235
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1237
perror("sigaction");
1238
exitcode = EXIT_FAILURE;
1148
1242
/* Run the main loop */