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() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
41
#include <stdint.h> /* uint16_t, uint32_t */
42
#include <stddef.h> /* NULL, size_t, ssize_t */
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, true */
46
#include <string.h> /* memset(), strcmp(), strlen(),
47
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
55
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
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 */
62
#include <assert.h> /* assert() */
63
#include <errno.h> /* perror(), errno */
64
#include <time.h> /* time() */
44
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
66
SIOCSIFFLAGS, if_indextoname(),
67
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
74
#include <argp.h> /* struct argp_option, error_t, struct
75
argp_state, struct argp,
76
argp_parse(), ARGP_KEY_ARG,
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
80
/* All Avahi types, constants and functions
47
83
#include <avahi-core/core.h>
48
84
#include <avahi-core/lookup.h>
49
85
#include <avahi-core/log.h>
51
87
#include <avahi-common/malloc.h>
52
88
#include <avahi-common/error.h>
54
/* Mandos client part */
55
#include <sys/types.h> /* socket(), inet_pton() */
56
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
57
struct in6_addr, inet_pton() */
58
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
59
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
61
#include <unistd.h> /* close() */
62
#include <netinet/in.h>
63
#include <stdbool.h> /* true */
64
#include <string.h> /* memset */
65
#include <arpa/inet.h> /* inet_pton() */
66
#include <iso646.h> /* not */
67
#include <net/if.h> /* IF_NAMESIZE */
91
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
94
init_gnutls_session(),
96
#include <gnutls/openpgp.h>
97
/* gnutls_certificate_set_openpgp_key_file(),
98
GNUTLS_OPENPGP_FMT_BASE64 */
70
#include <errno.h> /* perror() */
101
#include <gpgme.h> /* All GPGME types, constants and
104
GPGME_PROTOCOL_OpenPGP,
76
107
#define BUFFER_SIZE 256
78
static const char *keydir = "/conf/conf.d/mandos";
79
static const char *pubkeyfile = "pubkey.txt";
80
static const char *seckeyfile = "seckey.txt";
109
#define PATHDIR "/conf/conf.d/mandos"
110
#define SECKEY "seckey.txt"
111
#define PUBKEY "pubkey.txt"
82
113
bool debug = false;
84
const char mandos_protocol_version[] = "1";
86
/* Used for passing in values through all the callback functions */
114
static const char mandos_protocol_version[] = "1";
115
const char *argp_program_version = "mandos-client " VERSION;
116
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
118
/* Used for passing in values through the Avahi callback functions */
88
120
AvahiSimplePoll *simple_poll;
89
121
AvahiServer *server;
109
* Decrypt OpenPGP data using keyrings in HOMEDIR.
110
* Returns -1 on error
112
static ssize_t pgp_packet_decrypt (const char *cryptotext,
115
const char *homedir){
116
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){
118
152
gpgme_error_t rc;
120
size_t plaintext_capacity = 0;
121
ssize_t plaintext_length = 0;
122
153
gpgme_engine_info_t engine_info;
125
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
157
* Helper function to insert pub and seckey to the engine 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");
129
196
gpgme_check_version(NULL);
130
197
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
131
if (rc != GPG_ERR_NO_ERROR){
198
if(rc != GPG_ERR_NO_ERROR){
132
199
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
133
200
gpgme_strsource(rc), gpgme_strerror(rc));
137
/* Set GPGME home directory for the OpenPGP engine only */
138
rc = gpgme_get_engine_info (&engine_info);
139
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){
140
207
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
141
208
gpgme_strsource(rc), gpgme_strerror(rc));
144
211
while(engine_info != NULL){
145
212
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
146
213
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
147
engine_info->file_name, homedir);
214
engine_info->file_name, tempdir);
150
217
engine_info = engine_info->next;
152
219
if(engine_info == NULL){
153
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");
157
257
/* Create new GPGME data buffer from memory cryptotext */
158
258
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
160
if (rc != GPG_ERR_NO_ERROR){
260
if(rc != GPG_ERR_NO_ERROR){
161
261
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
162
262
gpgme_strsource(rc), gpgme_strerror(rc));
166
266
/* Create new empty GPGME data buffer for the plaintext */
167
267
rc = gpgme_data_new(&dh_plain);
168
if (rc != GPG_ERR_NO_ERROR){
268
if(rc != GPG_ERR_NO_ERROR){
169
269
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
170
270
gpgme_strsource(rc), gpgme_strerror(rc));
171
271
gpgme_data_release(dh_crypto);
175
/* Create new GPGME "context" */
176
rc = gpgme_new(&ctx);
177
if (rc != GPG_ERR_NO_ERROR){
178
fprintf(stderr, "bad gpgme_new: %s: %s\n",
179
gpgme_strsource(rc), gpgme_strerror(rc));
180
plaintext_length = -1;
184
275
/* Decrypt data from the cryptotext data buffer to the plaintext
186
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
187
if (rc != GPG_ERR_NO_ERROR){
277
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
278
if(rc != GPG_ERR_NO_ERROR){
188
279
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
189
280
gpgme_strsource(rc), gpgme_strerror(rc));
190
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;
191
310
goto decrypt_end;
195
314
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
199
gpgme_decrypt_result_t result;
200
result = gpgme_op_decrypt_result(ctx);
202
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
204
fprintf(stderr, "Unsupported algorithm: %s\n",
205
result->unsupported_algorithm);
206
fprintf(stderr, "Wrong key usage: %d\n",
207
result->wrong_key_usage);
208
if(result->file_name != NULL){
209
fprintf(stderr, "File name: %s\n", result->file_name);
211
gpgme_recipient_t recipient;
212
recipient = result->recipients;
214
while(recipient != NULL){
215
fprintf(stderr, "Public key algorithm: %s\n",
216
gpgme_pubkey_algo_name(recipient->pubkey_algo));
217
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
218
fprintf(stderr, "Secret key available: %s\n",
219
recipient->status == GPG_ERR_NO_SECKEY
221
recipient = recipient->next;
227
317
/* Seek back to the beginning of the GPGME plaintext data buffer */
228
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
229
perror("pgpme_data_seek");
318
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
319
perror("gpgme_data_seek");
230
320
plaintext_length = -1;
231
321
goto decrypt_end;
234
324
*plaintext = NULL;
236
plaintext_capacity = adjustbuffer(plaintext, (size_t)plaintext_length,
326
plaintext_capacity = adjustbuffer(plaintext,
327
(size_t)plaintext_length,
237
328
plaintext_capacity);
238
if (plaintext_capacity == 0){
329
if(plaintext_capacity == 0){
239
330
perror("adjustbuffer");
240
331
plaintext_length = -1;
241
332
goto decrypt_end;
312
406
/* OpenPGP credentials */
313
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
314
!= GNUTLS_E_SUCCESS) {
315
fprintf (stderr, "GnuTLS memory error: %s\n",
316
safer_gnutls_strerror(ret));
407
gnutls_certificate_allocate_credentials(&mc->cred);
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();
321
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
322
" 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,
326
424
ret = gnutls_certificate_set_openpgp_key_file
327
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
328
if (ret != GNUTLS_E_SUCCESS) {
425
(mc->cred, pubkeyfilename, seckeyfilename,
426
GNUTLS_OPENPGP_FMT_BASE64);
427
if(ret != GNUTLS_E_SUCCESS) {
330
429
"Error[%d] while reading the OpenPGP key pair ('%s',"
331
" '%s')\n", ret, pubkeyfile, seckeyfile);
332
fprintf(stdout, "The GnuTLS error is: %s\n",
430
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
431
fprintf(stderr, "The GnuTLS error is: %s\n",
333
432
safer_gnutls_strerror(ret));
337
436
/* GnuTLS server initialization */
338
437
ret = gnutls_dh_params_init(&mc->dh_params);
339
if (ret != GNUTLS_E_SUCCESS) {
340
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
341
" %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));
344
443
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
345
if (ret != GNUTLS_E_SUCCESS) {
346
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
347
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));
351
450
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
456
gnutls_certificate_free_credentials(mc->cred);
457
gnutls_global_deinit();
458
gnutls_dh_params_deinit(mc->dh_params);
356
static int init_gnutls_session(mandos_context *mc, gnutls_session_t *session){
462
static int init_gnutls_session(mandos_context *mc,
463
gnutls_session_t *session){
358
465
/* GnuTLS session creation */
359
466
ret = gnutls_init(session, GNUTLS_SERVER);
360
if (ret != GNUTLS_E_SUCCESS){
467
if(ret != GNUTLS_E_SUCCESS){
361
468
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
362
469
safer_gnutls_strerror(ret));
367
474
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
368
if (ret != GNUTLS_E_SUCCESS) {
475
if(ret != GNUTLS_E_SUCCESS) {
369
476
fprintf(stderr, "Syntax error at: %s\n", err);
370
477
fprintf(stderr, "GnuTLS error: %s\n",
371
478
safer_gnutls_strerror(ret));
479
gnutls_deinit(*session);
376
484
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
378
if (ret != GNUTLS_E_SUCCESS) {
486
if(ret != GNUTLS_E_SUCCESS) {
379
487
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
380
488
safer_gnutls_strerror(ret));
489
gnutls_deinit(*session);
384
493
/* ignore client certificate if any. */
385
gnutls_certificate_server_set_request (*session,
494
gnutls_certificate_server_set_request(*session,
388
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
497
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
732
833
char *connect_to = NULL;
834
char tempdir[] = "/tmp/mandosXXXXXX";
835
bool tempdir_created = false;
733
836
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
837
const char *seckey = PATHDIR "/" SECKEY;
838
const char *pubkey = PATHDIR "/" PUBKEY;
734
840
mandos_context mc = { .simple_poll = NULL, .server = NULL,
735
.dh_bits = 1024, .priority = "SECURE256"};
841
.dh_bits = 1024, .priority = "SECURE256"
842
":!CTYPE-X.509:+CTYPE-OPENPGP" };
843
bool gnutls_initialized = false;
844
bool gpgme_initialized = false;
738
/* Temporary int to get the address of for getopt_long */
739
int debug_int = debug ? 1 : 0;
741
struct option long_options[] = {
742
{"debug", no_argument, &debug_int, 1},
743
{"connect", required_argument, NULL, 'c'},
744
{"interface", required_argument, NULL, 'i'},
745
{"keydir", required_argument, NULL, 'd'},
746
{"seckey", required_argument, NULL, 's'},
747
{"pubkey", required_argument, NULL, 'p'},
748
{"dh-bits", required_argument, NULL, 'D'},
749
{"priority", required_argument, NULL, 'P'},
752
int option_index = 0;
753
ret = getopt_long (argc, argv, "i:", long_options,
780
mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);
847
struct argp_option options[] = {
848
{ .name = "debug", .key = 128,
849
.doc = "Debug mode", .group = 3 },
850
{ .name = "connect", .key = 'c',
851
.arg = "ADDRESS:PORT",
852
.doc = "Connect directly to a specific Mandos server",
854
{ .name = "interface", .key = 'i',
856
.doc = "Interface that will be used to search for Mandos"
859
{ .name = "seckey", .key = 's',
861
.doc = "OpenPGP secret key file base name",
863
{ .name = "pubkey", .key = 'p',
865
.doc = "OpenPGP public key file base name",
867
{ .name = "dh-bits", .key = 129,
869
.doc = "Bit length of the prime number used in the"
870
" Diffie-Hellman key exchange",
872
{ .name = "priority", .key = 130,
874
.doc = "GnuTLS priority string for the TLS handshake",
879
error_t parse_opt(int key, char *arg,
880
struct argp_state *state) {
882
case 128: /* --debug */
885
case 'c': /* --connect */
888
case 'i': /* --interface */
891
case 's': /* --seckey */
894
case 'p': /* --pubkey */
897
case 129: /* --dh-bits */
898
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
899
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
900
or arg[numchars] != '\0'){
901
fprintf(stderr, "Bad number of DH bits\n");
783
902
exit(EXIT_FAILURE);
787
mc.priority = optarg;
904
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
906
case 130: /* --priority */
791
/* getopt_long() has already printed a message about the
792
unrcognized option, so just exit. */
796
/* Set the global debug flag from the temporary int */
797
debug = debug_int ? true : false;
800
pubkeyfile = combinepath(keydir, pubkeyfile);
801
if (pubkeyfile == NULL){
802
perror("combinepath");
803
exitcode = EXIT_FAILURE;
807
seckeyfile = combinepath(keydir, seckeyfile);
808
if (seckeyfile == NULL){
809
perror("combinepath");
813
ret = init_gnutls_global(&mc);
815
fprintf(stderr, "init_gnutls_global\n");
914
return ARGP_ERR_UNKNOWN;
919
struct argp argp = { .options = options, .parser = parse_opt,
921
.doc = "Mandos client -- Get and decrypt"
922
" passwords from a Mandos server" };
923
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
924
if(ret == ARGP_ERR_UNKNOWN){
925
fprintf(stderr, "Unknown error while parsing arguments\n");
926
exitcode = EXIT_FAILURE;
931
/* If the interface is down, bring it up */
933
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
936
exitcode = EXIT_FAILURE;
939
strcpy(network.ifr_name, interface);
940
ret = ioctl(sd, SIOCGIFFLAGS, &network);
942
perror("ioctl SIOCGIFFLAGS");
943
exitcode = EXIT_FAILURE;
946
if((network.ifr_flags & IFF_UP) == 0){
947
network.ifr_flags |= IFF_UP;
948
ret = ioctl(sd, SIOCSIFFLAGS, &network);
950
perror("ioctl SIOCSIFFLAGS");
951
exitcode = EXIT_FAILURE;
955
ret = (int)TEMP_FAILURE_RETRY(close(sd));
822
969
ret = setuid(uid);
824
971
perror("setuid");
974
ret = init_gnutls_global(&mc, pubkey, seckey);
976
fprintf(stderr, "init_gnutls_global failed\n");
977
exitcode = EXIT_FAILURE;
980
gnutls_initialized = true;
983
if(mkdtemp(tempdir) == NULL){
987
tempdir_created = true;
989
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
990
fprintf(stderr, "init_gpgme failed\n");
991
exitcode = EXIT_FAILURE;
994
gpgme_initialized = true;
832
997
if_index = (AvahiIfIndex) if_nametoindex(interface);
833
998
if(if_index == 0){
834
999
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1000
exitcode = EXIT_FAILURE;
838
1004
if(connect_to != NULL){