33
32
#define _LARGEFILE_SOURCE
34
33
#define _FILE_OFFSET_BITS 64
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf */
40
#include <stdint.h> /* uint16_t, uint32_t */
41
#include <stddef.h> /* NULL, size_t, ssize_t */
42
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
44
#include <stdbool.h> /* bool, true */
45
#include <string.h> /* memset(), strcmp(), strlen(),
46
strerror(), asprintf(), strcpy() */
47
#include <sys/ioctl.h> /* ioctl */
48
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
49
sockaddr_in6, PF_INET6,
50
SOCK_STREAM, INET6_ADDRSTRLEN,
51
uid_t, gid_t, open(), opendir(),
53
#include <sys/stat.h> /* open() */
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
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 */
61
#include <assert.h> /* assert() */
62
#include <errno.h> /* perror(), errno */
63
#include <time.h> /* time() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
64
44
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
65
SIOCSIFFLAGS, if_indextoname(),
66
if_nametoindex(), IF_NAMESIZE */
67
#include <netinet/in.h>
68
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
69
getuid(), getgid(), setuid(),
71
#include <arpa/inet.h> /* inet_pton(), htons */
72
#include <iso646.h> /* not, and, or */
73
#include <argp.h> /* struct argp_option, error_t, struct
74
argp_state, struct argp,
75
argp_parse(), ARGP_KEY_ARG,
76
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
79
/* All Avahi types, constants and functions
82
47
#include <avahi-core/core.h>
83
48
#include <avahi-core/lookup.h>
84
49
#include <avahi-core/log.h>
86
51
#include <avahi-common/malloc.h>
87
52
#include <avahi-common/error.h>
90
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
93
init_gnutls_session(),
95
#include <gnutls/openpgp.h>
96
/* gnutls_certificate_set_openpgp_key_file(),
97
GNUTLS_OPENPGP_FMT_BASE64 */
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 */
68
#include <argp.h> /* struct argp_option,
69
struct argp_state, struct argp,
100
#include <gpgme.h> /* All GPGME types, constants and
103
GPGME_PROTOCOL_OpenPGP,
72
#include <errno.h> /* perror() */
106
75
#define BUFFER_SIZE 256
108
#define PATHDIR "/conf/conf.d/mandos"
109
#define SECKEY "seckey.txt"
110
#define PUBKEY "pubkey.txt"
112
77
bool debug = false;
113
static const char mandos_protocol_version[] = "1";
114
const char *argp_program_version = "mandos-client " VERSION;
78
const char *keydir = "/conf/conf.d/mandos";
79
const char *argp_program_version = "mandosclient 0.9";
115
80
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
81
const char mandos_protocol_version[] = "1";
117
/* Used for passing in values through the Avahi callback functions */
83
/* Used for passing in values through all the callback functions */
119
85
AvahiSimplePoll *simple_poll;
120
86
AvahiServer *server;
106
* Decrypt OpenPGP data using keyrings in HOMEDIR.
107
* Returns -1 on error
148
static bool init_gpgme(mandos_context *mc, const char *seckey,
149
const char *pubkey, const char *tempdir){
109
static ssize_t pgp_packet_decrypt (const char *cryptotext,
112
const char *homedir){
113
gpgme_data_t dh_crypto, dh_plain;
151
115
gpgme_error_t rc;
117
size_t plaintext_capacity = 0;
118
ssize_t plaintext_length = 0;
152
119
gpgme_engine_info_t engine_info;
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");
122
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
195
126
gpgme_check_version(NULL);
196
127
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
197
if(rc != GPG_ERR_NO_ERROR){
128
if (rc != GPG_ERR_NO_ERROR){
198
129
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
199
130
gpgme_strsource(rc), gpgme_strerror(rc));
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){
134
/* Set GPGME home directory for the OpenPGP engine only */
135
rc = gpgme_get_engine_info (&engine_info);
136
if (rc != GPG_ERR_NO_ERROR){
206
137
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
207
138
gpgme_strsource(rc), gpgme_strerror(rc));
210
141
while(engine_info != NULL){
211
142
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
212
143
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
213
engine_info->file_name, tempdir);
144
engine_info->file_name, homedir);
216
147
engine_info = engine_info->next;
218
149
if(engine_info == NULL){
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");
150
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
256
154
/* Create new GPGME data buffer from memory cryptotext */
257
155
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
259
if(rc != GPG_ERR_NO_ERROR){
157
if (rc != GPG_ERR_NO_ERROR){
260
158
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
261
159
gpgme_strsource(rc), gpgme_strerror(rc));
265
163
/* Create new empty GPGME data buffer for the plaintext */
266
164
rc = gpgme_data_new(&dh_plain);
267
if(rc != GPG_ERR_NO_ERROR){
165
if (rc != GPG_ERR_NO_ERROR){
268
166
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
269
167
gpgme_strsource(rc), gpgme_strerror(rc));
270
168
gpgme_data_release(dh_crypto);
172
/* Create new GPGME "context" */
173
rc = gpgme_new(&ctx);
174
if (rc != GPG_ERR_NO_ERROR){
175
fprintf(stderr, "bad gpgme_new: %s: %s\n",
176
gpgme_strsource(rc), gpgme_strerror(rc));
177
plaintext_length = -1;
274
181
/* Decrypt data from the cryptotext data buffer to the plaintext
276
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
277
if(rc != GPG_ERR_NO_ERROR){
183
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
184
if (rc != GPG_ERR_NO_ERROR){
278
185
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
279
186
gpgme_strsource(rc), gpgme_strerror(rc));
280
187
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;
309
188
goto decrypt_end;
313
192
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
196
gpgme_decrypt_result_t result;
197
result = gpgme_op_decrypt_result(ctx);
199
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
201
fprintf(stderr, "Unsupported algorithm: %s\n",
202
result->unsupported_algorithm);
203
fprintf(stderr, "Wrong key usage: %d\n",
204
result->wrong_key_usage);
205
if(result->file_name != NULL){
206
fprintf(stderr, "File name: %s\n", result->file_name);
208
gpgme_recipient_t recipient;
209
recipient = result->recipients;
211
while(recipient != NULL){
212
fprintf(stderr, "Public key algorithm: %s\n",
213
gpgme_pubkey_algo_name(recipient->pubkey_algo));
214
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
215
fprintf(stderr, "Secret key available: %s\n",
216
recipient->status == GPG_ERR_NO_SECKEY
218
recipient = recipient->next;
316
224
/* Seek back to the beginning of the GPGME plaintext data buffer */
317
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
318
perror("gpgme_data_seek");
225
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
226
perror("pgpme_data_seek");
319
227
plaintext_length = -1;
320
228
goto decrypt_end;
323
231
*plaintext = NULL;
325
plaintext_capacity = adjustbuffer(plaintext,
326
(size_t)plaintext_length,
233
plaintext_capacity = adjustbuffer(plaintext, (size_t)plaintext_length,
327
234
plaintext_capacity);
328
if(plaintext_capacity == 0){
235
if (plaintext_capacity == 0){
329
236
perror("adjustbuffer");
330
237
plaintext_length = -1;
331
238
goto decrypt_end;
405
311
/* OpenPGP credentials */
406
gnutls_certificate_allocate_credentials(&mc->cred);
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();
312
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
313
!= GNUTLS_E_SUCCESS) {
314
fprintf (stderr, "GnuTLS memory error: %s\n",
315
safer_gnutls_strerror(ret));
418
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
419
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
320
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
321
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
423
325
ret = gnutls_certificate_set_openpgp_key_file
424
(mc->cred, pubkeyfilename, seckeyfilename,
425
GNUTLS_OPENPGP_FMT_BASE64);
426
if(ret != GNUTLS_E_SUCCESS) {
326
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
327
if (ret != GNUTLS_E_SUCCESS) {
428
329
"Error[%d] while reading the OpenPGP key pair ('%s',"
429
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
430
fprintf(stderr, "The GnuTLS error is: %s\n",
330
" '%s')\n", ret, pubkeyfile, seckeyfile);
331
fprintf(stdout, "The GnuTLS error is: %s\n",
431
332
safer_gnutls_strerror(ret));
435
336
/* GnuTLS server initialization */
436
337
ret = gnutls_dh_params_init(&mc->dh_params);
437
if(ret != GNUTLS_E_SUCCESS) {
438
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
439
" %s\n", safer_gnutls_strerror(ret));
338
if (ret != GNUTLS_E_SUCCESS) {
339
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
340
" %s\n", safer_gnutls_strerror(ret));
442
343
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
443
if(ret != GNUTLS_E_SUCCESS) {
444
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
445
safer_gnutls_strerror(ret));
344
if (ret != GNUTLS_E_SUCCESS) {
345
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
346
safer_gnutls_strerror(ret));
449
350
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
455
gnutls_certificate_free_credentials(mc->cred);
456
gnutls_global_deinit();
457
gnutls_dh_params_deinit(mc->dh_params);
461
static int init_gnutls_session(mandos_context *mc,
462
gnutls_session_t *session){
355
static int init_gnutls_session(mandos_context *mc, gnutls_session_t *session){
464
357
/* GnuTLS session creation */
465
358
ret = gnutls_init(session, GNUTLS_SERVER);
466
if(ret != GNUTLS_E_SUCCESS){
359
if (ret != GNUTLS_E_SUCCESS){
467
360
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
468
361
safer_gnutls_strerror(ret));
473
366
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
474
if(ret != GNUTLS_E_SUCCESS) {
367
if (ret != GNUTLS_E_SUCCESS) {
475
368
fprintf(stderr, "Syntax error at: %s\n", err);
476
369
fprintf(stderr, "GnuTLS error: %s\n",
477
370
safer_gnutls_strerror(ret));
478
gnutls_deinit(*session);
483
375
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
485
if(ret != GNUTLS_E_SUCCESS) {
377
if (ret != GNUTLS_E_SUCCESS) {
486
378
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
487
379
safer_gnutls_strerror(ret));
488
gnutls_deinit(*session);
492
383
/* ignore client certificate if any. */
493
gnutls_certificate_server_set_request(*session,
384
gnutls_certificate_server_set_request (*session,
496
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
387
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
832
731
char *connect_to = NULL;
833
char tempdir[] = "/tmp/mandosXXXXXX";
834
732
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
835
const char *seckey = PATHDIR "/" SECKEY;
836
const char *pubkey = PATHDIR "/" PUBKEY;
733
const char *pubkeyfile = "pubkey.txt";
734
const char *seckeyfile = "seckey.txt";
838
735
mandos_context mc = { .simple_poll = NULL, .server = NULL,
839
.dh_bits = 1024, .priority = "SECURE256"
840
":!CTYPE-X.509:+CTYPE-OPENPGP" };
841
bool gnutls_initalized = false;
842
bool gpgme_initalized = false;
736
.dh_bits = 1024, .priority = "SECURE256"};
845
739
struct argp_option options[] = {
846
740
{ .name = "debug", .key = 128,
847
741
.doc = "Debug mode", .group = 3 },
848
742
{ .name = "connect", .key = 'c',
849
.arg = "ADDRESS:PORT",
850
.doc = "Connect directly to a specific Mandos server",
744
.doc = "Connect directly to a sepcified mandos server", .group = 1 },
852
745
{ .name = "interface", .key = 'i',
854
.doc = "Interface that will be used to search for Mandos"
747
.doc = "Interface that Avahi will conntect through", .group = 1 },
748
{ .name = "keydir", .key = 'd',
750
.doc = "Directory where the openpgp keyring is", .group = 1 },
857
751
{ .name = "seckey", .key = 's',
859
.doc = "OpenPGP secret key file base name",
753
.doc = "Secret openpgp key for gnutls authentication", .group = 1 },
861
754
{ .name = "pubkey", .key = 'p',
863
.doc = "OpenPGP public key file base name",
756
.doc = "Public openpgp key for gnutls authentication", .group = 2 },
865
757
{ .name = "dh-bits", .key = 129,
867
.doc = "Bit length of the prime number used in the"
868
" Diffie-Hellman key exchange",
759
.doc = "dh-bits to use in gnutls communication", .group = 2 },
870
760
{ .name = "priority", .key = 130,
872
.doc = "GnuTLS priority string for the TLS handshake",
762
.doc = "GNUTLS priority", .group = 1 },
877
error_t parse_opt(int key, char *arg,
878
struct argp_state *state) {
880
case 128: /* --debug */
767
error_t parse_opt (int key, char *arg, struct argp_state *state) {
768
/* Get the INPUT argument from `argp_parse', which we know is a
769
pointer to our plugin list pointer. */
883
case 'c': /* --connect */
884
775
connect_to = arg;
886
case 'i': /* --interface */
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");
791
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
900
794
exit(EXIT_FAILURE);
902
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
904
case 130: /* --priority */
905
798
mc.priority = arg;
907
800
case ARGP_KEY_ARG:
912
806
return ARGP_ERR_UNKNOWN;
917
811
struct argp argp = { .options = options, .parser = parse_opt,
919
.doc = "Mandos client -- Get and decrypt"
920
" passwords from a Mandos server" };
921
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
922
if(ret == ARGP_ERR_UNKNOWN){
923
fprintf(stderr, "Unknown error while parsing arguments\n");
924
exitcode = EXIT_FAILURE;
929
/* If the interface is down, bring it up */
931
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
934
exitcode = EXIT_FAILURE;
937
strcpy(network.ifr_name, interface);
938
ret = ioctl(sd, SIOCGIFFLAGS, &network);
940
perror("ioctl SIOCGIFFLAGS");
941
exitcode = EXIT_FAILURE;
944
if((network.ifr_flags & IFF_UP) == 0){
945
network.ifr_flags |= IFF_UP;
946
ret = ioctl(sd, SIOCSIFFLAGS, &network);
948
perror("ioctl SIOCSIFFLAGS");
949
exitcode = EXIT_FAILURE;
953
ret = (int)TEMP_FAILURE_RETRY(close(sd));
813
.doc = "Mandos client -- Get and decrypt passwords from mandos server" };
814
argp_parse (&argp, argc, argv, 0, 0, NULL);
817
pubkeyfile = combinepath(keydir, pubkeyfile);
818
if (pubkeyfile == NULL){
819
perror("combinepath");
820
exitcode = EXIT_FAILURE;
824
seckeyfile = combinepath(keydir, seckeyfile);
825
if (seckeyfile == NULL){
826
perror("combinepath");
830
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
832
fprintf(stderr, "init_gnutls_global\n");
962
839
ret = setuid(uid);
964
841
perror("setuid");
969
846
perror("setgid");
972
ret = init_gnutls_global(&mc, pubkey, seckey);
974
fprintf(stderr, "init_gnutls_global failed\n");
975
exitcode = EXIT_FAILURE;
978
gnutls_initalized = true;
981
if(mkdtemp(tempdir) == NULL){
987
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
988
fprintf(stderr, "gpgme_initalized failed\n");
989
exitcode = EXIT_FAILURE;
992
gpgme_initalized = true;
995
849
if_index = (AvahiIfIndex) if_nametoindex(interface);
996
850
if(if_index == 0){
997
851
fprintf(stderr, "No such interface: \"%s\"\n", interface);