47
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
50
sockaddr_in6, PF_INET6,
49
51
SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
52
55
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
56
struct in6_addr, inet_pton(),
58
#include <fcntl.h> /* open() */
59
#include <dirent.h> /* opendir(), struct dirent, readdir()
61
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
55
62
#include <assert.h> /* assert() */
56
63
#include <errno.h> /* perror(), errno */
57
#include <time.h> /* time() */
64
#include <time.h> /* nanosleep(), time() */
58
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
59
66
SIOCSIFFLAGS, if_indextoname(),
60
67
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
61
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
62
70
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
65
72
#include <arpa/inet.h> /* inet_pton(), htons */
66
#include <iso646.h> /* not, and */
73
#include <iso646.h> /* not, and, or */
67
74
#include <argp.h> /* struct argp_option, error_t, struct
68
75
argp_state, struct argp,
69
76
argp_parse(), ARGP_KEY_ARG,
70
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
78
#include <sys/klog.h> /* klogctl() */
73
81
/* All Avahi types, constants and functions
135
* Decrypt OpenPGP data using keyrings in HOMEDIR.
136
* Returns -1 on error
138
static ssize_t pgp_packet_decrypt (const char *cryptotext,
141
const char *homedir){
142
gpgme_data_t dh_crypto, dh_plain;
150
static bool init_gpgme(mandos_context *mc, const char *seckey,
151
const char *pubkey, const char *tempdir){
144
153
gpgme_error_t rc;
146
size_t plaintext_capacity = 0;
147
ssize_t plaintext_length = 0;
148
154
gpgme_engine_info_t engine_info;
151
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
158
* Helper function to insert pub and seckey to the engine keyring.
160
bool import_key(const char *filename){
162
gpgme_data_t pgp_data;
164
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
170
rc = gpgme_data_new_from_fd(&pgp_data, fd);
171
if(rc != GPG_ERR_NO_ERROR){
172
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
173
gpgme_strsource(rc), gpgme_strerror(rc));
177
rc = gpgme_op_import(mc->ctx, pgp_data);
178
if(rc != GPG_ERR_NO_ERROR){
179
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
180
gpgme_strsource(rc), gpgme_strerror(rc));
184
ret = (int)TEMP_FAILURE_RETRY(close(fd));
188
gpgme_data_release(pgp_data);
193
fprintf(stderr, "Initialize gpgme\n");
155
197
gpgme_check_version(NULL);
156
198
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
157
if (rc != GPG_ERR_NO_ERROR){
199
if(rc != GPG_ERR_NO_ERROR){
158
200
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
159
201
gpgme_strsource(rc), gpgme_strerror(rc));
163
/* Set GPGME home directory for the OpenPGP engine only */
164
rc = gpgme_get_engine_info (&engine_info);
165
if (rc != GPG_ERR_NO_ERROR){
205
/* Set GPGME home directory for the OpenPGP engine only */
206
rc = gpgme_get_engine_info(&engine_info);
207
if(rc != GPG_ERR_NO_ERROR){
166
208
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
167
209
gpgme_strsource(rc), gpgme_strerror(rc));
170
212
while(engine_info != NULL){
171
213
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
172
214
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
173
engine_info->file_name, homedir);
215
engine_info->file_name, tempdir);
176
218
engine_info = engine_info->next;
178
220
if(engine_info == NULL){
179
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
221
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
225
/* Create new GPGME "context" */
226
rc = gpgme_new(&(mc->ctx));
227
if(rc != GPG_ERR_NO_ERROR){
228
fprintf(stderr, "bad gpgme_new: %s: %s\n",
229
gpgme_strsource(rc), gpgme_strerror(rc));
233
if(not import_key(pubkey) or not import_key(seckey)){
241
* Decrypt OpenPGP data.
242
* Returns -1 on error
244
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
245
const char *cryptotext,
248
gpgme_data_t dh_crypto, dh_plain;
251
size_t plaintext_capacity = 0;
252
ssize_t plaintext_length = 0;
255
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
183
258
/* Create new GPGME data buffer from memory cryptotext */
184
259
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
186
if (rc != GPG_ERR_NO_ERROR){
261
if(rc != GPG_ERR_NO_ERROR){
187
262
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
188
263
gpgme_strsource(rc), gpgme_strerror(rc));
192
267
/* Create new empty GPGME data buffer for the plaintext */
193
268
rc = gpgme_data_new(&dh_plain);
194
if (rc != GPG_ERR_NO_ERROR){
269
if(rc != GPG_ERR_NO_ERROR){
195
270
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
196
271
gpgme_strsource(rc), gpgme_strerror(rc));
197
272
gpgme_data_release(dh_crypto);
201
/* Create new GPGME "context" */
202
rc = gpgme_new(&ctx);
203
if (rc != GPG_ERR_NO_ERROR){
204
fprintf(stderr, "bad gpgme_new: %s: %s\n",
205
gpgme_strsource(rc), gpgme_strerror(rc));
206
plaintext_length = -1;
210
276
/* Decrypt data from the cryptotext data buffer to the plaintext
212
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
213
if (rc != GPG_ERR_NO_ERROR){
278
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
279
if(rc != GPG_ERR_NO_ERROR){
214
280
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
215
281
gpgme_strsource(rc), gpgme_strerror(rc));
216
282
plaintext_length = -1;
218
284
gpgme_decrypt_result_t result;
219
result = gpgme_op_decrypt_result(ctx);
285
result = gpgme_op_decrypt_result(mc->ctx);
221
287
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
223
289
fprintf(stderr, "Unsupported algorithm: %s\n",
340
407
/* OpenPGP credentials */
341
408
gnutls_certificate_allocate_credentials(&mc->cred);
342
if (ret != GNUTLS_E_SUCCESS){
343
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
345
safer_gnutls_strerror(ret));
346
gnutls_global_deinit ();
409
if(ret != GNUTLS_E_SUCCESS){
410
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
414
safer_gnutls_strerror(ret));
415
gnutls_global_deinit();
351
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
352
" and keyfile %s as GnuTLS credentials\n", pubkeyfilename,
420
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
421
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
356
425
ret = gnutls_certificate_set_openpgp_key_file
357
426
(mc->cred, pubkeyfilename, seckeyfilename,
358
427
GNUTLS_OPENPGP_FMT_BASE64);
359
if (ret != GNUTLS_E_SUCCESS) {
428
if(ret != GNUTLS_E_SUCCESS) {
361
430
"Error[%d] while reading the OpenPGP key pair ('%s',"
362
431
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
363
fprintf(stdout, "The GnuTLS error is: %s\n",
432
fprintf(stderr, "The GnuTLS error is: %s\n",
364
433
safer_gnutls_strerror(ret));
368
437
/* GnuTLS server initialization */
369
438
ret = gnutls_dh_params_init(&mc->dh_params);
370
if (ret != GNUTLS_E_SUCCESS) {
371
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
372
" %s\n", safer_gnutls_strerror(ret));
439
if(ret != GNUTLS_E_SUCCESS) {
440
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
441
" %s\n", safer_gnutls_strerror(ret));
375
444
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
376
if (ret != GNUTLS_E_SUCCESS) {
377
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
378
safer_gnutls_strerror(ret));
445
if(ret != GNUTLS_E_SUCCESS) {
446
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
447
safer_gnutls_strerror(ret));
405
475
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
406
if (ret != GNUTLS_E_SUCCESS) {
476
if(ret != GNUTLS_E_SUCCESS) {
407
477
fprintf(stderr, "Syntax error at: %s\n", err);
408
478
fprintf(stderr, "GnuTLS error: %s\n",
409
479
safer_gnutls_strerror(ret));
410
gnutls_deinit (*session);
480
gnutls_deinit(*session);
415
485
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
417
if (ret != GNUTLS_E_SUCCESS) {
487
if(ret != GNUTLS_E_SUCCESS) {
418
488
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
419
489
safer_gnutls_strerror(ret));
420
gnutls_deinit (*session);
490
gnutls_deinit(*session);
424
494
/* ignore client certificate if any. */
425
gnutls_certificate_server_set_request (*session,
495
gnutls_certificate_server_set_request(*session,
428
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
498
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
565
638
buffer_capacity = adjustbuffer(&buffer, buffer_length,
566
639
buffer_capacity);
567
if (buffer_capacity == 0){
640
if(buffer_capacity == 0){
568
641
perror("adjustbuffer");
573
ret = gnutls_record_recv(session, buffer+buffer_length,
646
sret = gnutls_record_recv(session, buffer+buffer_length,
580
653
case GNUTLS_E_INTERRUPTED:
581
654
case GNUTLS_E_AGAIN:
583
656
case GNUTLS_E_REHANDSHAKE:
585
ret = gnutls_handshake (session);
658
ret = gnutls_handshake(session);
586
659
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
588
661
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
607
680
fprintf(stderr, "Closing TLS session\n");
610
gnutls_bye (session, GNUTLS_SHUT_RDWR);
683
gnutls_bye(session, GNUTLS_SHUT_RDWR);
612
if (buffer_length > 0){
613
decrypted_buffer_size = pgp_packet_decrypt(buffer,
685
if(buffer_length > 0){
686
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
617
if (decrypted_buffer_size >= 0){
689
if(decrypted_buffer_size >= 0){
619
691
while(written < (size_t) decrypted_buffer_size){
620
ret = (int)fwrite (decrypted_buffer + written, 1,
621
(size_t)decrypted_buffer_size - written,
692
ret = (int)fwrite(decrypted_buffer + written, 1,
693
(size_t)decrypted_buffer_size - written,
623
695
if(ret == 0 and ferror(stdout)){
625
697
fprintf(stderr, "Error writing encrypted data: %s\n",
681
756
avahi_address_snprint(ip, sizeof(ip), address);
683
758
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
684
PRIu16 ") on port %d\n", name, host_name, ip,
759
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
760
ip, (intmax_t)interface, port);
687
762
int ret = start_mandos_communication(ip, port, interface, mc);
689
764
avahi_simple_poll_quit(mc->simple_poll);
769
834
char *connect_to = NULL;
835
char tempdir[] = "/tmp/mandosXXXXXX";
836
bool tempdir_created = false;
770
837
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
771
char *pubkeyfilename = NULL;
772
char *seckeyfilename = NULL;
773
const char *pubkeyname = "pubkey.txt";
774
const char *seckeyname = "seckey.txt";
838
const char *seckey = PATHDIR "/" SECKEY;
839
const char *pubkey = PATHDIR "/" PUBKEY;
775
841
mandos_context mc = { .simple_poll = NULL, .server = NULL,
776
842
.dh_bits = 1024, .priority = "SECURE256"
777
843
":!CTYPE-X.509:+CTYPE-OPENPGP" };
778
bool gnutls_initalized = false;
844
bool gnutls_initialized = false;
845
bool gpgme_initialized = false;
781
849
struct argp_option options[] = {
812
876
.doc = "GnuTLS priority string for the TLS handshake",
878
{ .name = "delay", .key = 131,
880
.doc = "Maximum delay to wait for interface startup",
817
error_t parse_opt (int key, char *arg,
818
struct argp_state *state) {
819
/* Get the INPUT argument from `argp_parse', which we know is
820
a pointer to our plugin list pointer. */
885
error_t parse_opt(int key, char *arg,
886
struct argp_state *state) {
822
888
case 128: /* --debug */
828
894
case 'i': /* --interface */
831
case 'd': /* --keydir */
834
897
case 's': /* --seckey */
837
900
case 'p': /* --pubkey */
840
903
case 129: /* --dh-bits */
842
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
904
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
905
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
906
or arg[numchars] != '\0'){
907
fprintf(stderr, "Bad number of DH bits\n");
845
908
exit(EXIT_FAILURE);
910
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
848
912
case 130: /* --priority */
849
913
mc.priority = arg;
915
case 131: /* --delay */
916
ret = sscanf(arg, "%lf%n", &delay, &numchars);
917
if(ret < 1 or arg[numchars] != '\0'){
918
fprintf(stderr, "Bad delay\n");
851
922
case ARGP_KEY_ARG:
853
924
case ARGP_KEY_END:
863
934
.doc = "Mandos client -- Get and decrypt"
864
935
" passwords from a Mandos server" };
865
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
866
if (ret == ARGP_ERR_UNKNOWN){
936
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
937
if(ret == ARGP_ERR_UNKNOWN){
867
938
fprintf(stderr, "Unknown error while parsing arguments\n");
868
939
exitcode = EXIT_FAILURE;
873
pubkeyfilename = combinepath(keydir, pubkeyname);
874
if (pubkeyfilename == NULL){
875
perror("combinepath");
876
exitcode = EXIT_FAILURE;
880
seckeyfilename = combinepath(keydir, seckeyname);
881
if (seckeyfilename == NULL){
882
perror("combinepath");
883
exitcode = EXIT_FAILURE;
887
ret = init_gnutls_global(&mc, pubkeyfilename, seckeyfilename);
889
fprintf(stderr, "init_gnutls_global failed\n");
890
exitcode = EXIT_FAILURE;
893
gnutls_initalized = true;
896
944
/* If the interface is down, bring it up */
946
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
947
messages to mess up the prompt */
948
ret = klogctl(8, NULL, 5);
898
953
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
900
955
perror("socket");
901
956
exitcode = EXIT_FAILURE;
957
ret = klogctl(7, NULL, 0);
904
963
strcpy(network.ifr_name, interface);
905
964
ret = ioctl(sd, SIOCGIFFLAGS, &network);
907
966
perror("ioctl SIOCGIFFLAGS");
967
ret = klogctl(7, NULL, 0);
908
971
exitcode = EXIT_FAILURE;
915
978
perror("ioctl SIOCSIFFLAGS");
916
979
exitcode = EXIT_FAILURE;
980
ret = klogctl(7, NULL, 0);
987
/* sleep checking until interface is running */
988
for(int i=0; i < delay * 4; i++){
989
ret = ioctl(sd, SIOCGIFFLAGS, &network);
991
perror("ioctl SIOCGIFFLAGS");
992
} else if(network.ifr_flags & IFF_RUNNING){
995
struct timespec sleeptime = { .tv_nsec = 250000000 };
996
nanosleep(&sleeptime, NULL);
998
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1002
/* Restores kernel loglevel to default */
1003
ret = klogctl(7, NULL, 0);
926
1017
ret = setuid(uid);
928
1019
perror("setuid");
1022
ret = init_gnutls_global(&mc, pubkey, seckey);
1024
fprintf(stderr, "init_gnutls_global failed\n");
1025
exitcode = EXIT_FAILURE;
1028
gnutls_initialized = true;
1031
if(mkdtemp(tempdir) == NULL){
1035
tempdir_created = true;
1037
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1038
fprintf(stderr, "init_gpgme failed\n");
1039
exitcode = EXIT_FAILURE;
1042
gpgme_initialized = true;
936
1045
if_index = (AvahiIfIndex) if_nametoindex(interface);
937
1046
if(if_index == 0){
938
1047
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1048
exitcode = EXIT_FAILURE;
942
1052
if(connect_to != NULL){
1023
1135
/* Run the main loop */
1026
1138
fprintf(stderr, "Starting Avahi loop search\n");
1029
1141
avahi_simple_poll_loop(mc.simple_poll);
1034
1146
fprintf(stderr, "%s exiting\n", argv[0]);
1037
1149
/* Cleanup things */
1039
1151
avahi_s_service_browser_free(sb);
1041
if (mc.server != NULL)
1153
if(mc.server != NULL)
1042
1154
avahi_server_free(mc.server);
1044
if (mc.simple_poll != NULL)
1156
if(mc.simple_poll != NULL)
1045
1157
avahi_simple_poll_free(mc.simple_poll);
1046
free(pubkeyfilename);
1047
free(seckeyfilename);
1049
if (gnutls_initalized){
1159
if(gnutls_initialized){
1050
1160
gnutls_certificate_free_credentials(mc.cred);
1051
gnutls_global_deinit ();
1161
gnutls_global_deinit();
1162
gnutls_dh_params_deinit(mc.dh_params);
1165
if(gpgme_initialized){
1166
gpgme_release(mc.ctx);
1169
/* Removes the temp directory used by GPGME */
1170
if(tempdir_created){
1172
struct dirent *direntry;
1173
d = opendir(tempdir);
1175
if(errno != ENOENT){
1180
direntry = readdir(d);
1181
if(direntry == NULL){
1184
/* Skip "." and ".." */
1185
if(direntry->d_name[0] == '.'
1186
and (direntry->d_name[1] == '\0'
1187
or (direntry->d_name[1] == '.'
1188
and direntry->d_name[2] == '\0'))){
1191
char *fullname = NULL;
1192
ret = asprintf(&fullname, "%s/%s", tempdir,
1198
ret = remove(fullname);
1200
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1207
ret = rmdir(tempdir);
1208
if(ret == -1 and errno != ENOENT){
1054
1213
return exitcode;