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
41
#include <stdint.h> /* uint16_t, uint32_t */
40
42
#include <stddef.h> /* NULL, size_t, ssize_t */
41
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
45
#include <stdbool.h> /* bool, true */
44
46
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), memcpy(), strcpy() */
47
strerror(), asprintf(), strcpy() */
46
48
#include <sys/ioctl.h> /* ioctl */
47
#include <net/if.h> /* ifreq, SIOCGIFFLAGS, SIOCSIFFLAGS,
49
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
50
sockaddr_in6, PF_INET6,
51
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
53
55
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
54
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 */
56
62
#include <assert.h> /* assert() */
57
63
#include <errno.h> /* perror(), errno */
58
64
#include <time.h> /* time() */
59
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
60
66
SIOCSIFFLAGS, if_indextoname(),
61
67
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
62
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
63
70
getuid(), getgid(), setuid(),
65
#include <netinet/in.h>
66
72
#include <arpa/inet.h> /* inet_pton(), htons */
67
#include <iso646.h> /* not, and */
73
#include <iso646.h> /* not, and, or */
68
74
#include <argp.h> /* struct argp_option, error_t, struct
69
75
argp_state, struct argp,
70
76
argp_parse(), ARGP_KEY_ARG,
82
88
#include <avahi-common/error.h>
85
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and functions
91
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
87
94
init_gnutls_session(),
89
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
96
#include <gnutls/openpgp.h>
97
/* gnutls_certificate_set_openpgp_key_file(),
90
98
GNUTLS_OPENPGP_FMT_BASE64 */
93
#include <gpgme.h> /* All GPGME types, constants and functions
101
#include <gpgme.h> /* All GPGME types, constants and
95
104
GPGME_PROTOCOL_OpenPGP,
98
107
#define BUFFER_SIZE 256
109
#define PATHDIR "/conf/conf.d/mandos"
110
#define SECKEY "seckey.txt"
111
#define PUBKEY "pubkey.txt"
100
113
bool debug = false;
101
static const char *keydir = "/conf/conf.d/mandos";
102
114
static const char mandos_protocol_version[] = "1";
103
const char *argp_program_version = "mandosclient 0.9";
115
const char *argp_program_version = "mandos-client " VERSION;
104
116
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
106
118
/* Used for passing in values through the Avahi callback functions */
134
* Decrypt OpenPGP data using keyrings in HOMEDIR.
135
* Returns -1 on error
137
static ssize_t pgp_packet_decrypt (const char *cryptotext,
140
const char *homedir){
141
gpgme_data_t dh_crypto, dh_plain;
149
static bool init_gpgme(mandos_context *mc, const char *seckey,
150
const char *pubkey, const char *tempdir){
143
152
gpgme_error_t rc;
145
size_t plaintext_capacity = 0;
146
ssize_t plaintext_length = 0;
147
153
gpgme_engine_info_t engine_info;
150
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
157
* Helper function to insert pub and seckey to the enigne keyring.
159
bool import_key(const char *filename){
161
gpgme_data_t pgp_data;
163
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
169
rc = gpgme_data_new_from_fd(&pgp_data, fd);
170
if(rc != GPG_ERR_NO_ERROR){
171
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
172
gpgme_strsource(rc), gpgme_strerror(rc));
176
rc = gpgme_op_import(mc->ctx, pgp_data);
177
if(rc != GPG_ERR_NO_ERROR){
178
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
179
gpgme_strsource(rc), gpgme_strerror(rc));
183
ret = (int)TEMP_FAILURE_RETRY(close(fd));
187
gpgme_data_release(pgp_data);
192
fprintf(stderr, "Initialize gpgme\n");
154
196
gpgme_check_version(NULL);
155
197
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
156
if (rc != GPG_ERR_NO_ERROR){
198
if(rc != GPG_ERR_NO_ERROR){
157
199
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
158
200
gpgme_strsource(rc), gpgme_strerror(rc));
162
/* Set GPGME home directory for the OpenPGP engine only */
163
rc = gpgme_get_engine_info (&engine_info);
164
if (rc != GPG_ERR_NO_ERROR){
204
/* Set GPGME home directory for the OpenPGP engine only */
205
rc = gpgme_get_engine_info(&engine_info);
206
if(rc != GPG_ERR_NO_ERROR){
165
207
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
166
208
gpgme_strsource(rc), gpgme_strerror(rc));
169
211
while(engine_info != NULL){
170
212
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
171
213
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
172
engine_info->file_name, homedir);
214
engine_info->file_name, tempdir);
175
217
engine_info = engine_info->next;
177
219
if(engine_info == NULL){
178
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
220
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
224
/* Create new GPGME "context" */
225
rc = gpgme_new(&(mc->ctx));
226
if(rc != GPG_ERR_NO_ERROR){
227
fprintf(stderr, "bad gpgme_new: %s: %s\n",
228
gpgme_strsource(rc), gpgme_strerror(rc));
232
if(not import_key(pubkey) or not import_key(seckey)){
240
* Decrypt OpenPGP data.
241
* Returns -1 on error
243
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
244
const char *cryptotext,
247
gpgme_data_t dh_crypto, dh_plain;
250
size_t plaintext_capacity = 0;
251
ssize_t plaintext_length = 0;
254
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
182
257
/* Create new GPGME data buffer from memory cryptotext */
183
258
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
185
if (rc != GPG_ERR_NO_ERROR){
260
if(rc != GPG_ERR_NO_ERROR){
186
261
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
187
262
gpgme_strsource(rc), gpgme_strerror(rc));
191
266
/* Create new empty GPGME data buffer for the plaintext */
192
267
rc = gpgme_data_new(&dh_plain);
193
if (rc != GPG_ERR_NO_ERROR){
268
if(rc != GPG_ERR_NO_ERROR){
194
269
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
195
270
gpgme_strsource(rc), gpgme_strerror(rc));
196
271
gpgme_data_release(dh_crypto);
200
/* Create new GPGME "context" */
201
rc = gpgme_new(&ctx);
202
if (rc != GPG_ERR_NO_ERROR){
203
fprintf(stderr, "bad gpgme_new: %s: %s\n",
204
gpgme_strsource(rc), gpgme_strerror(rc));
205
plaintext_length = -1;
209
275
/* Decrypt data from the cryptotext data buffer to the plaintext
211
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
212
if (rc != GPG_ERR_NO_ERROR){
277
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
278
if(rc != GPG_ERR_NO_ERROR){
213
279
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
214
280
gpgme_strsource(rc), gpgme_strerror(rc));
215
281
plaintext_length = -1;
283
gpgme_decrypt_result_t result;
284
result = gpgme_op_decrypt_result(mc->ctx);
286
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
288
fprintf(stderr, "Unsupported algorithm: %s\n",
289
result->unsupported_algorithm);
290
fprintf(stderr, "Wrong key usage: %u\n",
291
result->wrong_key_usage);
292
if(result->file_name != NULL){
293
fprintf(stderr, "File name: %s\n", result->file_name);
295
gpgme_recipient_t recipient;
296
recipient = result->recipients;
298
while(recipient != NULL){
299
fprintf(stderr, "Public key algorithm: %s\n",
300
gpgme_pubkey_algo_name(recipient->pubkey_algo));
301
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
302
fprintf(stderr, "Secret key available: %s\n",
303
recipient->status == GPG_ERR_NO_SECKEY
305
recipient = recipient->next;
216
310
goto decrypt_end;
220
314
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
224
gpgme_decrypt_result_t result;
225
result = gpgme_op_decrypt_result(ctx);
227
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
229
fprintf(stderr, "Unsupported algorithm: %s\n",
230
result->unsupported_algorithm);
231
fprintf(stderr, "Wrong key usage: %d\n",
232
result->wrong_key_usage);
233
if(result->file_name != NULL){
234
fprintf(stderr, "File name: %s\n", result->file_name);
236
gpgme_recipient_t recipient;
237
recipient = result->recipients;
239
while(recipient != NULL){
240
fprintf(stderr, "Public key algorithm: %s\n",
241
gpgme_pubkey_algo_name(recipient->pubkey_algo));
242
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
243
fprintf(stderr, "Secret key available: %s\n",
244
recipient->status == GPG_ERR_NO_SECKEY
246
recipient = recipient->next;
252
317
/* Seek back to the beginning of the GPGME plaintext data buffer */
253
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
254
perror("pgpme_data_seek");
318
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
319
perror("gpgme_data_seek");
255
320
plaintext_length = -1;
256
321
goto decrypt_end;
340
406
/* OpenPGP credentials */
341
407
gnutls_certificate_allocate_credentials(&mc->cred);
342
if (ret != GNUTLS_E_SUCCESS){
343
fprintf (stderr, "GnuTLS memory error: %s\n",
344
safer_gnutls_strerror(ret));
345
gnutls_global_deinit ();
408
if(ret != GNUTLS_E_SUCCESS){
409
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
413
safer_gnutls_strerror(ret));
414
gnutls_global_deinit();
350
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
351
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
419
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
420
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
355
424
ret = gnutls_certificate_set_openpgp_key_file
356
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
357
if (ret != GNUTLS_E_SUCCESS) {
425
(mc->cred, pubkeyfilename, seckeyfilename,
426
GNUTLS_OPENPGP_FMT_BASE64);
427
if(ret != GNUTLS_E_SUCCESS) {
359
429
"Error[%d] while reading the OpenPGP key pair ('%s',"
360
" '%s')\n", ret, pubkeyfile, seckeyfile);
361
fprintf(stdout, "The GnuTLS error is: %s\n",
430
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
431
fprintf(stderr, "The GnuTLS error is: %s\n",
362
432
safer_gnutls_strerror(ret));
366
436
/* GnuTLS server initialization */
367
437
ret = gnutls_dh_params_init(&mc->dh_params);
368
if (ret != GNUTLS_E_SUCCESS) {
369
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
370
" %s\n", safer_gnutls_strerror(ret));
438
if(ret != GNUTLS_E_SUCCESS) {
439
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
440
" %s\n", safer_gnutls_strerror(ret));
373
443
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
374
if (ret != GNUTLS_E_SUCCESS) {
375
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
376
safer_gnutls_strerror(ret));
444
if(ret != GNUTLS_E_SUCCESS) {
445
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
446
safer_gnutls_strerror(ret));
380
450
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
386
456
gnutls_certificate_free_credentials(mc->cred);
387
457
gnutls_global_deinit();
458
gnutls_dh_params_deinit(mc->dh_params);
392
462
static int init_gnutls_session(mandos_context *mc,
404
474
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
405
if (ret != GNUTLS_E_SUCCESS) {
475
if(ret != GNUTLS_E_SUCCESS) {
406
476
fprintf(stderr, "Syntax error at: %s\n", err);
407
477
fprintf(stderr, "GnuTLS error: %s\n",
408
478
safer_gnutls_strerror(ret));
409
gnutls_deinit (*session);
479
gnutls_deinit(*session);
414
484
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
416
if (ret != GNUTLS_E_SUCCESS) {
486
if(ret != GNUTLS_E_SUCCESS) {
417
487
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
418
488
safer_gnutls_strerror(ret));
419
gnutls_deinit (*session);
489
gnutls_deinit(*session);
423
493
/* ignore client certificate if any. */
424
gnutls_certificate_server_set_request (*session,
494
gnutls_certificate_server_set_request(*session,
427
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
497
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
773
833
char *connect_to = NULL;
834
char tempdir[] = "/tmp/mandosXXXXXX";
774
835
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
775
const char *pubkeyfile = "pubkey.txt";
776
const char *seckeyfile = "seckey.txt";
836
const char *seckey = PATHDIR "/" SECKEY;
837
const char *pubkey = PATHDIR "/" PUBKEY;
777
839
mandos_context mc = { .simple_poll = NULL, .server = NULL,
778
.dh_bits = 1024, .priority = "SECURE256"};
779
bool gnutls_initalized = false;
840
.dh_bits = 1024, .priority = "SECURE256"
841
":!CTYPE-X.509:+CTYPE-OPENPGP" };
842
bool gnutls_initialized = false;
843
bool gpgme_initialized = false;
782
846
struct argp_option options[] = {
783
847
{ .name = "debug", .key = 128,
784
848
.doc = "Debug mode", .group = 3 },
785
849
{ .name = "connect", .key = 'c',
787
.doc = "Connect directly to a sepcified mandos server",
850
.arg = "ADDRESS:PORT",
851
.doc = "Connect directly to a specific Mandos server",
789
853
{ .name = "interface", .key = 'i',
791
.doc = "Interface that Avahi will conntect through",
793
{ .name = "keydir", .key = 'd',
795
.doc = "Directory where the openpgp keyring is",
855
.doc = "Interface that will be used to search for Mandos"
797
858
{ .name = "seckey", .key = 's',
799
.doc = "Secret openpgp key for gnutls authentication",
860
.doc = "OpenPGP secret key file base name",
801
862
{ .name = "pubkey", .key = 'p',
803
.doc = "Public openpgp key for gnutls authentication",
864
.doc = "OpenPGP public key file base name",
805
866
{ .name = "dh-bits", .key = 129,
807
.doc = "dh-bits to use in gnutls communication",
868
.doc = "Bit length of the prime number used in the"
869
" Diffie-Hellman key exchange",
809
871
{ .name = "priority", .key = 130,
811
.doc = "GNUTLS priority", .group = 1 },
873
.doc = "GnuTLS priority string for the TLS handshake",
816
error_t parse_opt (int key, char *arg,
817
struct argp_state *state) {
818
/* Get the INPUT argument from `argp_parse', which we know is
819
a pointer to our plugin list pointer. */
878
error_t parse_opt(int key, char *arg,
879
struct argp_state *state) {
881
case 128: /* --debug */
884
case 'c': /* --connect */
825
885
connect_to = arg;
887
case 'i': /* --interface */
841
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
890
case 's': /* --seckey */
893
case 'p': /* --pubkey */
896
case 129: /* --dh-bits */
897
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
898
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
899
or arg[numchars] != '\0'){
900
fprintf(stderr, "Bad number of DH bits\n");
844
901
exit(EXIT_FAILURE);
903
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
905
case 130: /* --priority */
848
906
mc.priority = arg;
850
908
case ARGP_KEY_ARG:
856
913
return ARGP_ERR_UNKNOWN;
861
918
struct argp argp = { .options = options, .parser = parse_opt,
863
920
.doc = "Mandos client -- Get and decrypt"
864
" passwords from mandos server" };
865
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
866
if (ret == ARGP_ERR_UNKNOWN){
867
fprintf(stderr, "Unkown error while parsing arguments\n");
868
exitcode = EXIT_FAILURE;
873
pubkeyfile = combinepath(keydir, pubkeyfile);
874
if (pubkeyfile == NULL){
875
perror("combinepath");
876
exitcode = EXIT_FAILURE;
880
seckeyfile = combinepath(keydir, seckeyfile);
881
if (seckeyfile == NULL){
882
perror("combinepath");
886
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
888
fprintf(stderr, "init_gnutls_global\n");
891
gnutls_initalized = true;
921
" passwords from a Mandos server" };
922
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
923
if(ret == ARGP_ERR_UNKNOWN){
924
fprintf(stderr, "Unknown error while parsing arguments\n");
925
exitcode = EXIT_FAILURE;
930
/* If the interface is down, bring it up */
932
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
935
exitcode = EXIT_FAILURE;
938
strcpy(network.ifr_name, interface);
939
ret = ioctl(sd, SIOCGIFFLAGS, &network);
941
perror("ioctl SIOCGIFFLAGS");
942
exitcode = EXIT_FAILURE;
945
if((network.ifr_flags & IFF_UP) == 0){
946
network.ifr_flags |= IFF_UP;
947
ret = ioctl(sd, SIOCSIFFLAGS, &network);
949
perror("ioctl SIOCSIFFLAGS");
950
exitcode = EXIT_FAILURE;
954
ret = (int)TEMP_FAILURE_RETRY(close(sd));
897
963
ret = setuid(uid);
899
965
perror("setuid");
904
970
perror("setgid");
973
ret = init_gnutls_global(&mc, pubkey, seckey);
975
fprintf(stderr, "init_gnutls_global failed\n");
976
exitcode = EXIT_FAILURE;
979
gnutls_initialized = true;
982
if(mkdtemp(tempdir) == NULL){
988
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
989
fprintf(stderr, "init_gpgme failed\n");
990
exitcode = EXIT_FAILURE;
993
gpgme_initialized = true;
907
996
if_index = (AvahiIfIndex) if_nametoindex(interface);
908
997
if(if_index == 0){
909
998
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1021
1085
/* Run the main loop */
1024
1088
fprintf(stderr, "Starting Avahi loop search\n");
1027
1091
avahi_simple_poll_loop(mc.simple_poll);
1032
1096
fprintf(stderr, "%s exiting\n", argv[0]);
1035
1099
/* Cleanup things */
1037
1101
avahi_s_service_browser_free(sb);
1039
if (mc.server != NULL)
1103
if(mc.server != NULL)
1040
1104
avahi_server_free(mc.server);
1042
if (mc.simple_poll != NULL)
1106
if(mc.simple_poll != NULL)
1043
1107
avahi_simple_poll_free(mc.simple_poll);
1047
if (gnutls_initalized){
1109
if(gnutls_initialized){
1048
1110
gnutls_certificate_free_credentials(mc.cred);
1049
gnutls_global_deinit ();
1111
gnutls_global_deinit();
1112
gnutls_dh_params_deinit(mc.dh_params);
1115
if(gpgme_initialized){
1116
gpgme_release(mc.ctx);
1119
/* Removes the temp directory used by GPGME */
1120
if(tempdir[0] != '\0'){
1122
struct dirent *direntry;
1123
d = opendir(tempdir);
1125
if(errno != ENOENT){
1130
direntry = readdir(d);
1131
if(direntry == NULL){
1134
/* Skip "." and ".." */
1135
if(direntry->d_name[0] == '.'
1136
and (direntry->d_name[1] == '\0'
1137
or (direntry->d_name[1] == '.'
1138
and direntry->d_name[2] == '\0'))){
1141
char *fullname = NULL;
1142
ret = asprintf(&fullname, "%s/%s", tempdir,
1148
ret = remove(fullname);
1150
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1157
ret = rmdir(tempdir);
1158
if(ret == -1 and errno != ENOENT){
1052
1163
return exitcode;