47
48
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
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49
sockaddr_in6, PF_INET6,
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SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
51
uid_t, gid_t, open(), opendir(),
53
#include <sys/stat.h> /* open() */
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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() */
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#include <dirent.h> /* opendir(), struct dirent, readdir()
60
#include <inttypes.h> /* PRIu16, SCNu16 */
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61
#include <assert.h> /* assert() */
56
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#include <errno.h> /* perror(), errno */
57
63
#include <time.h> /* time() */
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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
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SIOCSIFFLAGS, if_indextoname(),
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66
if_nametoindex(), IF_NAMESIZE */
67
#include <netinet/in.h>
61
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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
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69
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
65
71
#include <arpa/inet.h> /* inet_pton(), htons */
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#include <iso646.h> /* not, and */
72
#include <iso646.h> /* not, and, or */
67
73
#include <argp.h> /* struct argp_option, error_t, struct
68
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argp_state, struct argp,
69
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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);
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if(rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
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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",
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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
404
/* OpenPGP credentials */
341
405
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 ();
406
if(ret != GNUTLS_E_SUCCESS){
407
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious
409
safer_gnutls_strerror(ret));
410
gnutls_global_deinit();
351
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
352
" and keyfile %s as GnuTLS credentials\n", pubkeyfilename,
415
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
416
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
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420
ret = gnutls_certificate_set_openpgp_key_file
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421
(mc->cred, pubkeyfilename, seckeyfilename,
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422
GNUTLS_OPENPGP_FMT_BASE64);
359
if (ret != GNUTLS_E_SUCCESS) {
423
if(ret != GNUTLS_E_SUCCESS) {
361
425
"Error[%d] while reading the OpenPGP key pair ('%s',"
362
426
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
363
fprintf(stdout, "The GnuTLS error is: %s\n",
427
fprintf(stderr, "The GnuTLS error is: %s\n",
364
428
safer_gnutls_strerror(ret));
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432
/* GnuTLS server initialization */
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433
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));
434
if(ret != GNUTLS_E_SUCCESS) {
435
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
436
" %s\n", safer_gnutls_strerror(ret));
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439
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));
440
if(ret != GNUTLS_E_SUCCESS) {
441
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
442
safer_gnutls_strerror(ret));
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gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
388
452
gnutls_certificate_free_credentials(mc->cred);
389
453
gnutls_global_deinit();
454
gnutls_dh_params_deinit(mc->dh_params);
394
458
static int init_gnutls_session(mandos_context *mc,
406
470
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
407
if (ret != GNUTLS_E_SUCCESS) {
471
if(ret != GNUTLS_E_SUCCESS) {
408
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fprintf(stderr, "Syntax error at: %s\n", err);
409
473
fprintf(stderr, "GnuTLS error: %s\n",
410
474
safer_gnutls_strerror(ret));
411
gnutls_deinit (*session);
475
gnutls_deinit(*session);
416
480
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
418
if (ret != GNUTLS_E_SUCCESS) {
482
if(ret != GNUTLS_E_SUCCESS) {
419
483
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
420
484
safer_gnutls_strerror(ret));
421
gnutls_deinit (*session);
485
gnutls_deinit(*session);
425
489
/* ignore client certificate if any. */
426
gnutls_certificate_server_set_request (*session,
490
gnutls_certificate_server_set_request(*session,
429
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
493
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
561
626
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
566
631
buffer_capacity = adjustbuffer(&buffer, buffer_length,
567
632
buffer_capacity);
568
if (buffer_capacity == 0){
633
if(buffer_capacity == 0){
569
634
perror("adjustbuffer");
574
ret = gnutls_record_recv(session, buffer+buffer_length,
639
sret = gnutls_record_recv(session, buffer+buffer_length,
581
646
case GNUTLS_E_INTERRUPTED:
582
647
case GNUTLS_E_AGAIN:
584
649
case GNUTLS_E_REHANDSHAKE:
586
ret = gnutls_handshake (session);
651
ret = gnutls_handshake(session);
587
652
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
589
654
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
608
673
fprintf(stderr, "Closing TLS session\n");
611
gnutls_bye (session, GNUTLS_SHUT_RDWR);
676
gnutls_bye(session, GNUTLS_SHUT_RDWR);
613
if (buffer_length > 0){
614
decrypted_buffer_size = pgp_packet_decrypt(buffer,
678
if(buffer_length > 0){
679
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
618
if (decrypted_buffer_size >= 0){
682
if(decrypted_buffer_size >= 0){
620
684
while(written < (size_t) decrypted_buffer_size){
621
ret = (int)fwrite (decrypted_buffer + written, 1,
622
(size_t)decrypted_buffer_size - written,
685
ret = (int)fwrite(decrypted_buffer + written, 1,
686
(size_t)decrypted_buffer_size - written,
624
688
if(ret == 0 and ferror(stdout)){
626
690
fprintf(stderr, "Error writing encrypted data: %s\n",
770
825
char *connect_to = NULL;
826
char tempdir[] = "/tmp/mandosXXXXXX";
771
827
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";
828
const char *seckey = PATHDIR "/" SECKEY;
829
const char *pubkey = PATHDIR "/" PUBKEY;
776
831
mandos_context mc = { .simple_poll = NULL, .server = NULL,
777
.dh_bits = 1024, .priority = "SECURE256"};
832
.dh_bits = 1024, .priority = "SECURE256"
833
":!CTYPE-X.509:+CTYPE-OPENPGP" };
778
834
bool gnutls_initalized = false;
835
bool gpgme_initalized = false;
781
838
struct argp_option options[] = {
782
839
{ .name = "debug", .key = 128,
783
840
.doc = "Debug mode", .group = 3 },
784
841
{ .name = "connect", .key = 'c',
786
.doc = "Connect directly to a sepcified mandos server",
842
.arg = "ADDRESS:PORT",
843
.doc = "Connect directly to a specific Mandos server",
788
845
{ .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",
847
.doc = "Interface that will be used to search for Mandos"
796
850
{ .name = "seckey", .key = 's',
798
.doc = "Secret openpgp key for gnutls authentication",
852
.doc = "OpenPGP secret key file base name",
800
854
{ .name = "pubkey", .key = 'p',
802
.doc = "Public openpgp key for gnutls authentication",
856
.doc = "OpenPGP public key file base name",
804
858
{ .name = "dh-bits", .key = 129,
806
.doc = "dh-bits to use in gnutls communication",
860
.doc = "Bit length of the prime number used in the"
861
" Diffie-Hellman key exchange",
808
863
{ .name = "priority", .key = 130,
810
.doc = "GNUTLS priority", .group = 1 },
865
.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. */
870
error_t parse_opt(int key, char *arg,
871
struct argp_state *state) {
873
case 128: /* --debug */
876
case 'c': /* --connect */
824
877
connect_to = arg;
879
case 'i': /* --interface */
840
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
882
case 's': /* --seckey */
885
case 'p': /* --pubkey */
888
case 129: /* --dh-bits */
889
ret = sscanf(arg, "%u", &mc.dh_bits);
891
fprintf(stderr, "Bad number of DH bits\n");
843
892
exit(EXIT_FAILURE);
895
case 130: /* --priority */
847
896
mc.priority = arg;
849
898
case ARGP_KEY_ARG:
851
900
case ARGP_KEY_END:
859
908
struct argp argp = { .options = options, .parser = parse_opt,
861
910
.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){
911
" passwords from a Mandos server" };
912
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
913
if(ret == ARGP_ERR_UNKNOWN){
865
914
fprintf(stderr, "Unknown error while parsing arguments\n");
866
915
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
920
/* If the interface is down, bring it up */
944
ret = (int)TEMP_FAILURE_RETRY(close(sd));
924
953
ret = setuid(uid);
926
955
perror("setuid");
931
960
perror("setgid");
963
ret = init_gnutls_global(&mc, pubkey, seckey);
965
fprintf(stderr, "init_gnutls_global failed\n");
966
exitcode = EXIT_FAILURE;
969
gnutls_initalized = true;
972
if(mkdtemp(tempdir) == NULL){
978
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
979
fprintf(stderr, "gpgme_initalized failed\n");
980
exitcode = EXIT_FAILURE;
983
gpgme_initalized = true;
934
986
if_index = (AvahiIfIndex) if_nametoindex(interface);
935
987
if(if_index == 0){
936
988
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1021
1073
/* Run the main loop */
1024
1076
fprintf(stderr, "Starting Avahi loop search\n");
1027
1079
avahi_simple_poll_loop(mc.simple_poll);
1032
1084
fprintf(stderr, "%s exiting\n", argv[0]);
1035
1087
/* Cleanup things */
1037
1089
avahi_s_service_browser_free(sb);
1039
if (mc.server != NULL)
1091
if(mc.server != NULL)
1040
1092
avahi_server_free(mc.server);
1042
if (mc.simple_poll != NULL)
1094
if(mc.simple_poll != NULL)
1043
1095
avahi_simple_poll_free(mc.simple_poll);
1044
free(pubkeyfilename);
1045
free(seckeyfilename);
1047
if (gnutls_initalized){
1097
if(gnutls_initalized){
1048
1098
gnutls_certificate_free_credentials(mc.cred);
1049
gnutls_global_deinit ();
1099
gnutls_global_deinit();
1100
gnutls_dh_params_deinit(mc.dh_params);
1103
if(gpgme_initalized){
1104
gpgme_release(mc.ctx);
1107
/* Removes the temp directory used by GPGME */
1108
if(tempdir[0] != '\0'){
1110
struct dirent *direntry;
1111
d = opendir(tempdir);
1113
if(errno != ENOENT){
1118
direntry = readdir(d);
1119
if(direntry == NULL){
1122
if(direntry->d_type == DT_REG){
1123
char *fullname = NULL;
1124
ret = asprintf(&fullname, "%s/%s", tempdir,
1130
ret = unlink(fullname);
1132
fprintf(stderr, "unlink(\"%s\"): %s",
1133
fullname, strerror(errno));
1140
ret = rmdir(tempdir);
1141
if(ret == -1 and errno != ENOENT){
1052
1146
return exitcode;