32
33
#define _LARGEFILE_SOURCE
33
34
#define _FILE_OFFSET_BITS 64
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf */
39
40
#include <stdint.h> /* uint16_t, uint32_t */
40
41
#include <stddef.h> /* NULL, size_t, ssize_t */
41
42
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
44
#include <stdbool.h> /* bool, true */
44
45
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), memcpy(), strcpy() */
46
strerror(), asprintf(), strcpy() */
46
47
#include <sys/ioctl.h> /* ioctl */
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
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
55
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,
81
87
#include <avahi-common/error.h>
84
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and functions
90
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
86
93
init_gnutls_session(),
88
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
95
#include <gnutls/openpgp.h>
96
/* gnutls_certificate_set_openpgp_key_file(),
89
97
GNUTLS_OPENPGP_FMT_BASE64 */
92
#include <gpgme.h> /* All GPGME types, constants and functions
100
#include <gpgme.h> /* All GPGME types, constants and
94
103
GPGME_PROTOCOL_OpenPGP,
97
106
#define BUFFER_SIZE 256
108
#define PATHDIR "/conf/conf.d/mandos"
109
#define SECKEY "seckey.txt"
110
#define PUBKEY "pubkey.txt"
99
112
bool debug = false;
100
static const char *keydir = "/conf/conf.d/mandos";
101
113
static const char mandos_protocol_version[] = "1";
102
const char *argp_program_version = "password-request 1.0";
114
const char *argp_program_version = "mandos-client " VERSION;
103
115
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
105
117
/* Used for passing in values through the Avahi callback functions */
133
* Decrypt OpenPGP data using keyrings in HOMEDIR.
134
* Returns -1 on error
136
static ssize_t pgp_packet_decrypt (const char *cryptotext,
139
const char *homedir){
140
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){
142
151
gpgme_error_t rc;
144
size_t plaintext_capacity = 0;
145
ssize_t plaintext_length = 0;
146
152
gpgme_engine_info_t engine_info;
149
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");
153
195
gpgme_check_version(NULL);
154
196
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
155
if (rc != GPG_ERR_NO_ERROR){
197
if(rc != GPG_ERR_NO_ERROR){
156
198
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
157
199
gpgme_strsource(rc), gpgme_strerror(rc));
161
/* Set GPGME home directory for the OpenPGP engine only */
162
rc = gpgme_get_engine_info (&engine_info);
163
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){
164
206
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
165
207
gpgme_strsource(rc), gpgme_strerror(rc));
168
210
while(engine_info != NULL){
169
211
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
170
212
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
171
engine_info->file_name, homedir);
213
engine_info->file_name, tempdir);
174
216
engine_info = engine_info->next;
176
218
if(engine_info == NULL){
177
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");
181
256
/* Create new GPGME data buffer from memory cryptotext */
182
257
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
184
if (rc != GPG_ERR_NO_ERROR){
259
if(rc != GPG_ERR_NO_ERROR){
185
260
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
186
261
gpgme_strsource(rc), gpgme_strerror(rc));
190
265
/* Create new empty GPGME data buffer for the plaintext */
191
266
rc = gpgme_data_new(&dh_plain);
192
if (rc != GPG_ERR_NO_ERROR){
267
if(rc != GPG_ERR_NO_ERROR){
193
268
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
194
269
gpgme_strsource(rc), gpgme_strerror(rc));
195
270
gpgme_data_release(dh_crypto);
199
/* Create new GPGME "context" */
200
rc = gpgme_new(&ctx);
201
if (rc != GPG_ERR_NO_ERROR){
202
fprintf(stderr, "bad gpgme_new: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
204
plaintext_length = -1;
208
274
/* Decrypt data from the cryptotext data buffer to the plaintext
210
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
211
if (rc != GPG_ERR_NO_ERROR){
276
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
277
if(rc != GPG_ERR_NO_ERROR){
212
278
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
213
279
gpgme_strsource(rc), gpgme_strerror(rc));
214
280
plaintext_length = -1;
282
gpgme_decrypt_result_t result;
283
result = gpgme_op_decrypt_result(mc->ctx);
285
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
287
fprintf(stderr, "Unsupported algorithm: %s\n",
288
result->unsupported_algorithm);
289
fprintf(stderr, "Wrong key usage: %u\n",
290
result->wrong_key_usage);
291
if(result->file_name != NULL){
292
fprintf(stderr, "File name: %s\n", result->file_name);
294
gpgme_recipient_t recipient;
295
recipient = result->recipients;
297
while(recipient != NULL){
298
fprintf(stderr, "Public key algorithm: %s\n",
299
gpgme_pubkey_algo_name(recipient->pubkey_algo));
300
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
301
fprintf(stderr, "Secret key available: %s\n",
302
recipient->status == GPG_ERR_NO_SECKEY
304
recipient = recipient->next;
215
309
goto decrypt_end;
219
313
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
223
gpgme_decrypt_result_t result;
224
result = gpgme_op_decrypt_result(ctx);
226
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
228
fprintf(stderr, "Unsupported algorithm: %s\n",
229
result->unsupported_algorithm);
230
fprintf(stderr, "Wrong key usage: %u\n",
231
result->wrong_key_usage);
232
if(result->file_name != NULL){
233
fprintf(stderr, "File name: %s\n", result->file_name);
235
gpgme_recipient_t recipient;
236
recipient = result->recipients;
238
while(recipient != NULL){
239
fprintf(stderr, "Public key algorithm: %s\n",
240
gpgme_pubkey_algo_name(recipient->pubkey_algo));
241
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
242
fprintf(stderr, "Secret key available: %s\n",
243
recipient->status == GPG_ERR_NO_SECKEY
245
recipient = recipient->next;
251
316
/* Seek back to the beginning of the GPGME plaintext data buffer */
252
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
253
perror("pgpme_data_seek");
317
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
318
perror("gpgme_data_seek");
254
319
plaintext_length = -1;
255
320
goto decrypt_end;
339
405
/* OpenPGP credentials */
340
406
gnutls_certificate_allocate_credentials(&mc->cred);
341
if (ret != GNUTLS_E_SUCCESS){
342
fprintf (stderr, "GnuTLS memory error: %s\n",
343
safer_gnutls_strerror(ret));
344
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();
349
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
350
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
418
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
419
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
354
423
ret = gnutls_certificate_set_openpgp_key_file
355
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
356
if (ret != GNUTLS_E_SUCCESS) {
424
(mc->cred, pubkeyfilename, seckeyfilename,
425
GNUTLS_OPENPGP_FMT_BASE64);
426
if(ret != GNUTLS_E_SUCCESS) {
358
428
"Error[%d] while reading the OpenPGP key pair ('%s',"
359
" '%s')\n", ret, pubkeyfile, seckeyfile);
360
fprintf(stdout, "The GnuTLS error is: %s\n",
429
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
430
fprintf(stderr, "The GnuTLS error is: %s\n",
361
431
safer_gnutls_strerror(ret));
365
435
/* GnuTLS server initialization */
366
436
ret = gnutls_dh_params_init(&mc->dh_params);
367
if (ret != GNUTLS_E_SUCCESS) {
368
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
369
" %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));
372
442
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
373
if (ret != GNUTLS_E_SUCCESS) {
374
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
375
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));
379
449
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
385
455
gnutls_certificate_free_credentials(mc->cred);
386
456
gnutls_global_deinit();
457
gnutls_dh_params_deinit(mc->dh_params);
391
461
static int init_gnutls_session(mandos_context *mc,
403
473
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
404
if (ret != GNUTLS_E_SUCCESS) {
474
if(ret != GNUTLS_E_SUCCESS) {
405
475
fprintf(stderr, "Syntax error at: %s\n", err);
406
476
fprintf(stderr, "GnuTLS error: %s\n",
407
477
safer_gnutls_strerror(ret));
408
gnutls_deinit (*session);
478
gnutls_deinit(*session);
413
483
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
415
if (ret != GNUTLS_E_SUCCESS) {
485
if(ret != GNUTLS_E_SUCCESS) {
416
486
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
417
487
safer_gnutls_strerror(ret));
418
gnutls_deinit (*session);
488
gnutls_deinit(*session);
422
492
/* ignore client certificate if any. */
423
gnutls_certificate_server_set_request (*session,
493
gnutls_certificate_server_set_request(*session,
426
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
496
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
558
631
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
563
636
buffer_capacity = adjustbuffer(&buffer, buffer_length,
564
637
buffer_capacity);
565
if (buffer_capacity == 0){
638
if(buffer_capacity == 0){
566
639
perror("adjustbuffer");
571
ret = gnutls_record_recv(session, buffer+buffer_length,
644
sret = gnutls_record_recv(session, buffer+buffer_length,
578
651
case GNUTLS_E_INTERRUPTED:
579
652
case GNUTLS_E_AGAIN:
581
654
case GNUTLS_E_REHANDSHAKE:
583
ret = gnutls_handshake (session);
656
ret = gnutls_handshake(session);
584
657
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
586
659
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
605
678
fprintf(stderr, "Closing TLS session\n");
608
gnutls_bye (session, GNUTLS_SHUT_RDWR);
681
gnutls_bye(session, GNUTLS_SHUT_RDWR);
610
if (buffer_length > 0){
611
decrypted_buffer_size = pgp_packet_decrypt(buffer,
683
if(buffer_length > 0){
684
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
615
if (decrypted_buffer_size >= 0){
687
if(decrypted_buffer_size >= 0){
617
689
while(written < (size_t) decrypted_buffer_size){
618
ret = (int)fwrite (decrypted_buffer + written, 1,
619
(size_t)decrypted_buffer_size - written,
690
ret = (int)fwrite(decrypted_buffer + written, 1,
691
(size_t)decrypted_buffer_size - written,
621
693
if(ret == 0 and ferror(stdout)){
623
695
fprintf(stderr, "Error writing encrypted data: %s\n",
774
832
char *connect_to = NULL;
833
char tempdir[] = "/tmp/mandosXXXXXX";
775
834
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
776
const char *pubkeyfile = "pubkey.txt";
777
const char *seckeyfile = "seckey.txt";
835
const char *seckey = PATHDIR "/" SECKEY;
836
const char *pubkey = PATHDIR "/" PUBKEY;
778
838
mandos_context mc = { .simple_poll = NULL, .server = NULL,
779
.dh_bits = 1024, .priority = "SECURE256"};
780
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;
783
845
struct argp_option options[] = {
784
846
{ .name = "debug", .key = 128,
785
847
.doc = "Debug mode", .group = 3 },
786
848
{ .name = "connect", .key = 'c',
788
.doc = "Connect directly to a sepcified mandos server",
849
.arg = "ADDRESS:PORT",
850
.doc = "Connect directly to a specific Mandos server",
790
852
{ .name = "interface", .key = 'i',
792
.doc = "Interface that Avahi will conntect through",
794
{ .name = "keydir", .key = 'd',
796
.doc = "Directory where the openpgp keyring is",
854
.doc = "Interface that will be used to search for Mandos"
798
857
{ .name = "seckey", .key = 's',
800
.doc = "Secret openpgp key for gnutls authentication",
859
.doc = "OpenPGP secret key file base name",
802
861
{ .name = "pubkey", .key = 'p',
804
.doc = "Public openpgp key for gnutls authentication",
863
.doc = "OpenPGP public key file base name",
806
865
{ .name = "dh-bits", .key = 129,
808
.doc = "dh-bits to use in gnutls communication",
867
.doc = "Bit length of the prime number used in the"
868
" Diffie-Hellman key exchange",
810
870
{ .name = "priority", .key = 130,
812
.doc = "GNUTLS priority", .group = 1 },
872
.doc = "GnuTLS priority string for the TLS handshake",
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. */
877
error_t parse_opt(int key, char *arg,
878
struct argp_state *state) {
880
case 128: /* --debug */
883
case 'c': /* --connect */
826
884
connect_to = arg;
886
case 'i': /* --interface */
842
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");
845
900
exit(EXIT_FAILURE);
902
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
904
case 130: /* --priority */
849
905
mc.priority = arg;
851
907
case ARGP_KEY_ARG:
857
912
return ARGP_ERR_UNKNOWN;
862
917
struct argp argp = { .options = options, .parser = parse_opt,
864
919
.doc = "Mandos client -- Get and decrypt"
865
" passwords from mandos server" };
866
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
867
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){
868
923
fprintf(stderr, "Unknown error while parsing arguments\n");
869
924
exitcode = EXIT_FAILURE;
874
pubkeyfile = combinepath(keydir, pubkeyfile);
875
if (pubkeyfile == NULL){
876
perror("combinepath");
877
exitcode = EXIT_FAILURE;
881
seckeyfile = combinepath(keydir, seckeyfile);
882
if (seckeyfile == NULL){
883
perror("combinepath");
884
exitcode = EXIT_FAILURE;
888
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
890
fprintf(stderr, "init_gnutls_global failed\n");
891
exitcode = EXIT_FAILURE;
894
gnutls_initalized = true;
897
929
/* If the interface is down, bring it up */
1024
1084
/* Run the main loop */
1027
1087
fprintf(stderr, "Starting Avahi loop search\n");
1030
1090
avahi_simple_poll_loop(mc.simple_poll);
1035
1095
fprintf(stderr, "%s exiting\n", argv[0]);
1038
1098
/* Cleanup things */
1040
1100
avahi_s_service_browser_free(sb);
1042
if (mc.server != NULL)
1102
if(mc.server != NULL)
1043
1103
avahi_server_free(mc.server);
1045
if (mc.simple_poll != NULL)
1105
if(mc.simple_poll != NULL)
1046
1106
avahi_simple_poll_free(mc.simple_poll);
1050
if (gnutls_initalized){
1108
if(gnutls_initialized){
1051
1109
gnutls_certificate_free_credentials(mc.cred);
1052
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){
1055
1157
return exitcode;