47
48
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
49
sockaddr_in6, PF_INET6,
49
50
SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
51
uid_t, gid_t, open(), opendir(),
53
#include <sys/stat.h> /* open() */
52
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#include <sys/socket.h> /* socket(), struct sockaddr_in6,
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struct in6_addr, inet_pton(),
57
#include <fcntl.h> /* open() */
58
#include <dirent.h> /* opendir(), struct dirent, readdir()
60
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
55
61
#include <assert.h> /* assert() */
56
62
#include <errno.h> /* perror(), errno */
57
63
#include <time.h> /* time() */
58
64
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
59
65
SIOCSIFFLAGS, if_indextoname(),
60
66
if_nametoindex(), IF_NAMESIZE */
67
#include <netinet/in.h>
61
68
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
62
69
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
65
71
#include <arpa/inet.h> /* inet_pton(), htons */
66
#include <iso646.h> /* not, and */
72
#include <iso646.h> /* not, and, or */
67
73
#include <argp.h> /* struct argp_option, error_t, struct
68
74
argp_state, struct argp,
69
75
argp_parse(), ARGP_KEY_ARG,
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;
148
static bool init_gpgme(mandos_context *mc, const char *seckey,
149
const char *pubkey, const char *tempdir){
144
151
gpgme_error_t rc;
146
size_t plaintext_capacity = 0;
147
ssize_t plaintext_length = 0;
148
152
gpgme_engine_info_t engine_info;
151
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
156
* Helper function to insert pub and seckey to the enigne keyring.
158
bool import_key(const char *filename){
160
gpgme_data_t pgp_data;
162
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
168
rc = gpgme_data_new_from_fd(&pgp_data, fd);
169
if(rc != GPG_ERR_NO_ERROR){
170
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
171
gpgme_strsource(rc), gpgme_strerror(rc));
175
rc = gpgme_op_import(mc->ctx, pgp_data);
176
if(rc != GPG_ERR_NO_ERROR){
177
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
178
gpgme_strsource(rc), gpgme_strerror(rc));
182
ret = (int)TEMP_FAILURE_RETRY(close(fd));
186
gpgme_data_release(pgp_data);
191
fprintf(stderr, "Initialize gpgme\n");
155
195
gpgme_check_version(NULL);
156
196
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
157
if (rc != GPG_ERR_NO_ERROR){
197
if(rc != GPG_ERR_NO_ERROR){
158
198
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
159
199
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){
203
/* Set GPGME home directory for the OpenPGP engine only */
204
rc = gpgme_get_engine_info(&engine_info);
205
if(rc != GPG_ERR_NO_ERROR){
166
206
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
167
207
gpgme_strsource(rc), gpgme_strerror(rc));
170
210
while(engine_info != NULL){
171
211
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
172
212
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
173
engine_info->file_name, homedir);
213
engine_info->file_name, tempdir);
176
216
engine_info = engine_info->next;
178
218
if(engine_info == NULL){
179
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
219
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
223
/* Create new GPGME "context" */
224
rc = gpgme_new(&(mc->ctx));
225
if(rc != GPG_ERR_NO_ERROR){
226
fprintf(stderr, "bad gpgme_new: %s: %s\n",
227
gpgme_strsource(rc), gpgme_strerror(rc));
231
if(not import_key(pubkey) or not import_key(seckey)){
239
* Decrypt OpenPGP data.
240
* Returns -1 on error
242
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
243
const char *cryptotext,
246
gpgme_data_t dh_crypto, dh_plain;
249
size_t plaintext_capacity = 0;
250
ssize_t plaintext_length = 0;
253
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
183
256
/* Create new GPGME data buffer from memory cryptotext */
184
257
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
186
if (rc != GPG_ERR_NO_ERROR){
259
if(rc != GPG_ERR_NO_ERROR){
187
260
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
188
261
gpgme_strsource(rc), gpgme_strerror(rc));
192
265
/* Create new empty GPGME data buffer for the plaintext */
193
266
rc = gpgme_data_new(&dh_plain);
194
if (rc != GPG_ERR_NO_ERROR){
267
if(rc != GPG_ERR_NO_ERROR){
195
268
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
196
269
gpgme_strsource(rc), gpgme_strerror(rc));
197
270
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
274
/* 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){
276
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
277
if(rc != GPG_ERR_NO_ERROR){
214
278
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
215
279
gpgme_strsource(rc), gpgme_strerror(rc));
216
280
plaintext_length = -1;
218
282
gpgme_decrypt_result_t result;
219
result = gpgme_op_decrypt_result(ctx);
283
result = gpgme_op_decrypt_result(mc->ctx);
221
285
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
223
287
fprintf(stderr, "Unsupported algorithm: %s\n",
340
405
/* OpenPGP credentials */
341
406
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 ();
407
if(ret != GNUTLS_E_SUCCESS){
408
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
412
safer_gnutls_strerror(ret));
413
gnutls_global_deinit();
351
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
352
" and keyfile %s as GnuTLS credentials\n", pubkeyfilename,
418
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
419
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
356
423
ret = gnutls_certificate_set_openpgp_key_file
357
424
(mc->cred, pubkeyfilename, seckeyfilename,
358
425
GNUTLS_OPENPGP_FMT_BASE64);
359
if (ret != GNUTLS_E_SUCCESS) {
426
if(ret != GNUTLS_E_SUCCESS) {
361
428
"Error[%d] while reading the OpenPGP key pair ('%s',"
362
429
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
363
fprintf(stdout, "The GnuTLS error is: %s\n",
430
fprintf(stderr, "The GnuTLS error is: %s\n",
364
431
safer_gnutls_strerror(ret));
368
435
/* GnuTLS server initialization */
369
436
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));
437
if(ret != GNUTLS_E_SUCCESS) {
438
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
439
" %s\n", safer_gnutls_strerror(ret));
375
442
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));
443
if(ret != GNUTLS_E_SUCCESS) {
444
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
445
safer_gnutls_strerror(ret));
382
449
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
388
455
gnutls_certificate_free_credentials(mc->cred);
389
456
gnutls_global_deinit();
457
gnutls_dh_params_deinit(mc->dh_params);
394
461
static int init_gnutls_session(mandos_context *mc,
406
473
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
407
if (ret != GNUTLS_E_SUCCESS) {
474
if(ret != GNUTLS_E_SUCCESS) {
408
475
fprintf(stderr, "Syntax error at: %s\n", err);
409
476
fprintf(stderr, "GnuTLS error: %s\n",
410
477
safer_gnutls_strerror(ret));
411
gnutls_deinit (*session);
478
gnutls_deinit(*session);
416
483
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
418
if (ret != GNUTLS_E_SUCCESS) {
485
if(ret != GNUTLS_E_SUCCESS) {
419
486
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
420
487
safer_gnutls_strerror(ret));
421
gnutls_deinit (*session);
488
gnutls_deinit(*session);
425
492
/* ignore client certificate if any. */
426
gnutls_certificate_server_set_request (*session,
493
gnutls_certificate_server_set_request(*session,
429
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
496
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
561
631
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
566
636
buffer_capacity = adjustbuffer(&buffer, buffer_length,
567
637
buffer_capacity);
568
if (buffer_capacity == 0){
638
if(buffer_capacity == 0){
569
639
perror("adjustbuffer");
574
ret = gnutls_record_recv(session, buffer+buffer_length,
644
sret = gnutls_record_recv(session, buffer+buffer_length,
581
651
case GNUTLS_E_INTERRUPTED:
582
652
case GNUTLS_E_AGAIN:
584
654
case GNUTLS_E_REHANDSHAKE:
586
ret = gnutls_handshake (session);
656
ret = gnutls_handshake(session);
587
657
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
589
659
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
608
678
fprintf(stderr, "Closing TLS session\n");
611
gnutls_bye (session, GNUTLS_SHUT_RDWR);
681
gnutls_bye(session, GNUTLS_SHUT_RDWR);
613
if (buffer_length > 0){
614
decrypted_buffer_size = pgp_packet_decrypt(buffer,
683
if(buffer_length > 0){
684
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
618
if (decrypted_buffer_size >= 0){
687
if(decrypted_buffer_size >= 0){
620
689
while(written < (size_t) decrypted_buffer_size){
621
ret = (int)fwrite (decrypted_buffer + written, 1,
622
(size_t)decrypted_buffer_size - written,
690
ret = (int)fwrite(decrypted_buffer + written, 1,
691
(size_t)decrypted_buffer_size - written,
624
693
if(ret == 0 and ferror(stdout)){
626
695
fprintf(stderr, "Error writing encrypted data: %s\n",
682
754
avahi_address_snprint(ip, sizeof(ip), address);
684
756
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
685
PRIu16 ") on port %d\n", name, host_name, ip,
757
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
758
ip, (intmax_t)interface, port);
688
760
int ret = start_mandos_communication(ip, port, interface, mc);
690
762
avahi_simple_poll_quit(mc->simple_poll);
770
832
char *connect_to = NULL;
833
char tempdir[] = "/tmp/mandosXXXXXX";
771
834
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
772
char *pubkeyfilename = NULL;
773
char *seckeyfilename = NULL;
774
const char *pubkeyname = "pubkey.txt";
775
const char *seckeyname = "seckey.txt";
835
const char *seckey = PATHDIR "/" SECKEY;
836
const char *pubkey = PATHDIR "/" PUBKEY;
776
838
mandos_context mc = { .simple_poll = NULL, .server = NULL,
777
.dh_bits = 1024, .priority = "SECURE256"};
778
bool gnutls_initalized = false;
839
.dh_bits = 1024, .priority = "SECURE256"
840
":!CTYPE-X.509:+CTYPE-OPENPGP" };
841
bool gnutls_initialized = false;
842
bool gpgme_initialized = false;
781
845
struct argp_option options[] = {
782
846
{ .name = "debug", .key = 128,
783
847
.doc = "Debug mode", .group = 3 },
784
848
{ .name = "connect", .key = 'c',
786
.doc = "Connect directly to a sepcified mandos server",
849
.arg = "ADDRESS:PORT",
850
.doc = "Connect directly to a specific Mandos server",
788
852
{ .name = "interface", .key = 'i',
790
.doc = "Interface that Avahi will conntect through",
792
{ .name = "keydir", .key = 'd',
794
.doc = "Directory where the openpgp keyring is",
854
.doc = "Interface that will be used to search for Mandos"
796
857
{ .name = "seckey", .key = 's',
798
.doc = "Secret openpgp key for gnutls authentication",
859
.doc = "OpenPGP secret key file base name",
800
861
{ .name = "pubkey", .key = 'p',
802
.doc = "Public openpgp key for gnutls authentication",
863
.doc = "OpenPGP public key file base name",
804
865
{ .name = "dh-bits", .key = 129,
806
.doc = "dh-bits to use in gnutls communication",
867
.doc = "Bit length of the prime number used in the"
868
" Diffie-Hellman key exchange",
808
870
{ .name = "priority", .key = 130,
810
.doc = "GNUTLS priority", .group = 1 },
872
.doc = "GnuTLS priority string for the TLS handshake",
815
error_t parse_opt (int key, char *arg,
816
struct argp_state *state) {
817
/* Get the INPUT argument from `argp_parse', which we know is
818
a pointer to our plugin list pointer. */
877
error_t parse_opt(int key, char *arg,
878
struct argp_state *state) {
880
case 128: /* --debug */
883
case 'c': /* --connect */
824
884
connect_to = arg;
886
case 'i': /* --interface */
840
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
889
case 's': /* --seckey */
892
case 'p': /* --pubkey */
895
case 129: /* --dh-bits */
896
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
897
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
898
or arg[numchars] != '\0'){
899
fprintf(stderr, "Bad number of DH bits\n");
843
900
exit(EXIT_FAILURE);
902
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
904
case 130: /* --priority */
847
905
mc.priority = arg;
849
907
case ARGP_KEY_ARG:
851
909
case ARGP_KEY_END:
859
917
struct argp argp = { .options = options, .parser = parse_opt,
861
919
.doc = "Mandos client -- Get and decrypt"
862
" passwords from mandos server" };
863
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
864
if (ret == ARGP_ERR_UNKNOWN){
920
" passwords from a Mandos server" };
921
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
922
if(ret == ARGP_ERR_UNKNOWN){
865
923
fprintf(stderr, "Unknown error while parsing arguments\n");
866
924
exitcode = EXIT_FAILURE;
871
pubkeyfilename = combinepath(keydir, pubkeyname);
872
if (pubkeyfilename == NULL){
873
perror("combinepath");
874
exitcode = EXIT_FAILURE;
878
seckeyfilename = combinepath(keydir, seckeyname);
879
if (seckeyfilename == NULL){
880
perror("combinepath");
881
exitcode = EXIT_FAILURE;
885
ret = init_gnutls_global(&mc, pubkeyfilename, seckeyfilename);
887
fprintf(stderr, "init_gnutls_global failed\n");
888
exitcode = EXIT_FAILURE;
891
gnutls_initalized = true;
894
929
/* If the interface is down, bring it up */
953
ret = (int)TEMP_FAILURE_RETRY(close(sd));
924
962
ret = setuid(uid);
926
964
perror("setuid");
931
969
perror("setgid");
972
ret = init_gnutls_global(&mc, pubkey, seckey);
974
fprintf(stderr, "init_gnutls_global failed\n");
975
exitcode = EXIT_FAILURE;
978
gnutls_initialized = true;
981
if(mkdtemp(tempdir) == NULL){
987
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
988
fprintf(stderr, "init_gpgme failed\n");
989
exitcode = EXIT_FAILURE;
992
gpgme_initialized = true;
934
995
if_index = (AvahiIfIndex) if_nametoindex(interface);
935
996
if(if_index == 0){
936
997
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1021
1084
/* Run the main loop */
1024
1087
fprintf(stderr, "Starting Avahi loop search\n");
1027
1090
avahi_simple_poll_loop(mc.simple_poll);
1032
1095
fprintf(stderr, "%s exiting\n", argv[0]);
1035
1098
/* Cleanup things */
1037
1100
avahi_s_service_browser_free(sb);
1039
if (mc.server != NULL)
1102
if(mc.server != NULL)
1040
1103
avahi_server_free(mc.server);
1042
if (mc.simple_poll != NULL)
1105
if(mc.simple_poll != NULL)
1043
1106
avahi_simple_poll_free(mc.simple_poll);
1044
free(pubkeyfilename);
1045
free(seckeyfilename);
1047
if (gnutls_initalized){
1108
if(gnutls_initialized){
1048
1109
gnutls_certificate_free_credentials(mc.cred);
1049
gnutls_global_deinit ();
1110
gnutls_global_deinit();
1111
gnutls_dh_params_deinit(mc.dh_params);
1114
if(gpgme_initialized){
1115
gpgme_release(mc.ctx);
1118
/* Removes the temp directory used by GPGME */
1119
if(tempdir[0] != '\0'){
1121
struct dirent *direntry;
1122
d = opendir(tempdir);
1124
if(errno != ENOENT){
1129
direntry = readdir(d);
1130
if(direntry == NULL){
1133
if(direntry->d_type == DT_REG){
1134
char *fullname = NULL;
1135
ret = asprintf(&fullname, "%s/%s", tempdir,
1141
ret = unlink(fullname);
1143
fprintf(stderr, "unlink(\"%s\"): %s",
1144
fullname, strerror(errno));
1151
ret = rmdir(tempdir);
1152
if(ret == -1 and errno != ENOENT){
1052
1157
return exitcode;