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(),
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> /* nanosleep(), time() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
65
44
#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 */
78
#include <sys/klog.h> /* klogctl() */
81
/* All Avahi types, constants and functions
84
47
#include <avahi-core/core.h>
85
48
#include <avahi-core/lookup.h>
86
49
#include <avahi-core/log.h>
88
51
#include <avahi-common/malloc.h>
89
52
#include <avahi-common/error.h>
92
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
95
init_gnutls_session(),
97
#include <gnutls/openpgp.h>
98
/* gnutls_certificate_set_openpgp_key_file(),
99
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 */
102
#include <gpgme.h> /* All GPGME types, constants and
105
GPGME_PROTOCOL_OpenPGP,
70
#include <errno.h> /* perror() */
108
76
#define BUFFER_SIZE 256
110
#define PATHDIR "/conf/conf.d/mandos"
111
#define SECKEY "seckey.txt"
112
#define PUBKEY "pubkey.txt"
78
static const char *keydir = "/conf/conf.d/mandos";
79
static const char *pubkeyfile = "pubkey.txt";
80
static const char *seckeyfile = "seckey.txt";
114
82
bool debug = false;
115
static const char mandos_protocol_version[] = "1";
116
const char *argp_program_version = "mandos-client " VERSION;
117
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
119
/* Used for passing in values through the Avahi callback functions */
84
const char mandos_protocol_version[] = "1";
86
/* Used for passing in values through all the callback functions */
121
88
AvahiSimplePoll *simple_poll;
122
89
AvahiServer *server;
109
* Decrypt OpenPGP data using keyrings in HOMEDIR.
110
* Returns -1 on error
150
static bool init_gpgme(mandos_context *mc, const char *seckey,
151
const char *pubkey, const char *tempdir){
112
static ssize_t pgp_packet_decrypt (const char *cryptotext,
115
const char *homedir){
116
gpgme_data_t dh_crypto, dh_plain;
153
118
gpgme_error_t rc;
120
size_t plaintext_capacity = 0;
121
ssize_t plaintext_length = 0;
154
122
gpgme_engine_info_t engine_info;
158
* Helper function to insert pub and seckey to the engine keyring.
160
bool import_key(const char *filename){
162
gpgme_data_t pgp_data;
164
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
170
rc = gpgme_data_new_from_fd(&pgp_data, fd);
171
if(rc != GPG_ERR_NO_ERROR){
172
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
173
gpgme_strsource(rc), gpgme_strerror(rc));
177
rc = gpgme_op_import(mc->ctx, pgp_data);
178
if(rc != GPG_ERR_NO_ERROR){
179
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
180
gpgme_strsource(rc), gpgme_strerror(rc));
184
ret = (int)TEMP_FAILURE_RETRY(close(fd));
188
gpgme_data_release(pgp_data);
193
fprintf(stderr, "Initialize gpgme\n");
125
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
197
129
gpgme_check_version(NULL);
198
130
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
199
if(rc != GPG_ERR_NO_ERROR){
131
if (rc != GPG_ERR_NO_ERROR){
200
132
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
201
133
gpgme_strsource(rc), gpgme_strerror(rc));
205
/* Set GPGME home directory for the OpenPGP engine only */
206
rc = gpgme_get_engine_info(&engine_info);
207
if(rc != GPG_ERR_NO_ERROR){
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){
208
140
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
209
141
gpgme_strsource(rc), gpgme_strerror(rc));
212
144
while(engine_info != NULL){
213
145
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
214
146
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
215
engine_info->file_name, tempdir);
147
engine_info->file_name, homedir);
218
150
engine_info = engine_info->next;
220
152
if(engine_info == NULL){
221
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
225
/* Create new GPGME "context" */
226
rc = gpgme_new(&(mc->ctx));
227
if(rc != GPG_ERR_NO_ERROR){
228
fprintf(stderr, "bad gpgme_new: %s: %s\n",
229
gpgme_strsource(rc), gpgme_strerror(rc));
233
if(not import_key(pubkey) or not import_key(seckey)){
241
* Decrypt OpenPGP data.
242
* Returns -1 on error
244
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
245
const char *cryptotext,
248
gpgme_data_t dh_crypto, dh_plain;
251
size_t plaintext_capacity = 0;
252
ssize_t plaintext_length = 0;
255
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
153
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
258
157
/* Create new GPGME data buffer from memory cryptotext */
259
158
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
261
if(rc != GPG_ERR_NO_ERROR){
160
if (rc != GPG_ERR_NO_ERROR){
262
161
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
263
162
gpgme_strsource(rc), gpgme_strerror(rc));
267
166
/* Create new empty GPGME data buffer for the plaintext */
268
167
rc = gpgme_data_new(&dh_plain);
269
if(rc != GPG_ERR_NO_ERROR){
168
if (rc != GPG_ERR_NO_ERROR){
270
169
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
271
170
gpgme_strsource(rc), gpgme_strerror(rc));
272
171
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;
276
184
/* Decrypt data from the cryptotext data buffer to the plaintext
278
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
279
if(rc != GPG_ERR_NO_ERROR){
186
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
187
if (rc != GPG_ERR_NO_ERROR){
280
188
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
281
189
gpgme_strsource(rc), gpgme_strerror(rc));
282
190
plaintext_length = -1;
284
gpgme_decrypt_result_t result;
285
result = gpgme_op_decrypt_result(mc->ctx);
287
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
289
fprintf(stderr, "Unsupported algorithm: %s\n",
290
result->unsupported_algorithm);
291
fprintf(stderr, "Wrong key usage: %u\n",
292
result->wrong_key_usage);
293
if(result->file_name != NULL){
294
fprintf(stderr, "File name: %s\n", result->file_name);
296
gpgme_recipient_t recipient;
297
recipient = result->recipients;
299
while(recipient != NULL){
300
fprintf(stderr, "Public key algorithm: %s\n",
301
gpgme_pubkey_algo_name(recipient->pubkey_algo));
302
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
303
fprintf(stderr, "Secret key available: %s\n",
304
recipient->status == GPG_ERR_NO_SECKEY
306
recipient = recipient->next;
311
191
goto decrypt_end;
315
195
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;
318
227
/* Seek back to the beginning of the GPGME plaintext data buffer */
319
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
320
perror("gpgme_data_seek");
228
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
229
perror("pgpme_data_seek");
321
230
plaintext_length = -1;
322
231
goto decrypt_end;
325
234
*plaintext = NULL;
327
plaintext_capacity = adjustbuffer(plaintext,
328
(size_t)plaintext_length,
236
plaintext_capacity = adjustbuffer(plaintext, (size_t)plaintext_length,
329
237
plaintext_capacity);
330
if(plaintext_capacity == 0){
238
if (plaintext_capacity == 0){
331
239
perror("adjustbuffer");
332
240
plaintext_length = -1;
333
241
goto decrypt_end;
407
312
/* OpenPGP credentials */
408
gnutls_certificate_allocate_credentials(&mc->cred);
409
if(ret != GNUTLS_E_SUCCESS){
410
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
414
safer_gnutls_strerror(ret));
415
gnutls_global_deinit();
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));
420
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
421
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
321
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
322
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
425
326
ret = gnutls_certificate_set_openpgp_key_file
426
(mc->cred, pubkeyfilename, seckeyfilename,
427
GNUTLS_OPENPGP_FMT_BASE64);
428
if(ret != GNUTLS_E_SUCCESS) {
327
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
328
if (ret != GNUTLS_E_SUCCESS) {
430
330
"Error[%d] while reading the OpenPGP key pair ('%s',"
431
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
432
fprintf(stderr, "The GnuTLS error is: %s\n",
331
" '%s')\n", ret, pubkeyfile, seckeyfile);
332
fprintf(stdout, "The GnuTLS error is: %s\n",
433
333
safer_gnutls_strerror(ret));
437
337
/* GnuTLS server initialization */
438
338
ret = gnutls_dh_params_init(&mc->dh_params);
439
if(ret != GNUTLS_E_SUCCESS) {
440
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
441
" %s\n", safer_gnutls_strerror(ret));
339
if (ret != GNUTLS_E_SUCCESS) {
340
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
341
" %s\n", safer_gnutls_strerror(ret));
444
344
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
445
if(ret != GNUTLS_E_SUCCESS) {
446
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
447
safer_gnutls_strerror(ret));
345
if (ret != GNUTLS_E_SUCCESS) {
346
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
347
safer_gnutls_strerror(ret));
451
351
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
457
gnutls_certificate_free_credentials(mc->cred);
458
gnutls_global_deinit();
459
gnutls_dh_params_deinit(mc->dh_params);
463
static int init_gnutls_session(mandos_context *mc,
464
gnutls_session_t *session){
356
static int init_gnutls_session(mandos_context *mc, gnutls_session_t *session){
466
358
/* GnuTLS session creation */
467
359
ret = gnutls_init(session, GNUTLS_SERVER);
468
if(ret != GNUTLS_E_SUCCESS){
360
if (ret != GNUTLS_E_SUCCESS){
469
361
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
470
362
safer_gnutls_strerror(ret));
834
732
char *connect_to = NULL;
835
char tempdir[] = "/tmp/mandosXXXXXX";
836
bool tempdir_created = false;
837
733
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
838
const char *seckey = PATHDIR "/" SECKEY;
839
const char *pubkey = PATHDIR "/" PUBKEY;
841
734
mandos_context mc = { .simple_poll = NULL, .server = NULL,
842
.dh_bits = 1024, .priority = "SECURE256"
843
":!CTYPE-X.509:+CTYPE-OPENPGP" };
844
bool gnutls_initialized = false;
845
bool gpgme_initialized = false;
735
.dh_bits = 1024, .priority = "SECURE256"};
849
struct argp_option options[] = {
850
{ .name = "debug", .key = 128,
851
.doc = "Debug mode", .group = 3 },
852
{ .name = "connect", .key = 'c',
853
.arg = "ADDRESS:PORT",
854
.doc = "Connect directly to a specific Mandos server",
856
{ .name = "interface", .key = 'i',
858
.doc = "Interface that will be used to search for Mandos"
861
{ .name = "seckey", .key = 's',
863
.doc = "OpenPGP secret key file base name",
865
{ .name = "pubkey", .key = 'p',
867
.doc = "OpenPGP public key file base name",
869
{ .name = "dh-bits", .key = 129,
871
.doc = "Bit length of the prime number used in the"
872
" Diffie-Hellman key exchange",
874
{ .name = "priority", .key = 130,
876
.doc = "GnuTLS priority string for the TLS handshake",
878
{ .name = "delay", .key = 131,
880
.doc = "Maximum delay to wait for interface startup",
885
error_t parse_opt(int key, char *arg,
886
struct argp_state *state) {
888
case 128: /* --debug */
891
case 'c': /* --connect */
894
case 'i': /* --interface */
897
case 's': /* --seckey */
900
case 'p': /* --pubkey */
903
case 129: /* --dh-bits */
904
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
905
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
906
or arg[numchars] != '\0'){
907
fprintf(stderr, "Bad number of DH bits\n");
910
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
912
case 130: /* --priority */
915
case 131: /* --delay */
916
ret = sscanf(arg, "%lf%n", &delay, &numchars);
917
if(ret < 1 or arg[numchars] != '\0'){
918
fprintf(stderr, "Bad delay\n");
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);
787
mc.priority = optarg;
927
return ARGP_ERR_UNKNOWN;
932
struct argp argp = { .options = options, .parser = parse_opt,
934
.doc = "Mandos client -- Get and decrypt"
935
" passwords from a Mandos server" };
936
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
937
if(ret == ARGP_ERR_UNKNOWN){
938
fprintf(stderr, "Unknown error while parsing arguments\n");
939
exitcode = EXIT_FAILURE;
944
/* If the interface is down, bring it up */
946
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
947
messages to mess up the prompt */
948
ret = klogctl(8, NULL, 5);
953
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
956
exitcode = EXIT_FAILURE;
957
ret = klogctl(7, NULL, 0);
963
strcpy(network.ifr_name, interface);
964
ret = ioctl(sd, SIOCGIFFLAGS, &network);
966
perror("ioctl SIOCGIFFLAGS");
967
ret = klogctl(7, NULL, 0);
971
exitcode = EXIT_FAILURE;
974
if((network.ifr_flags & IFF_UP) == 0){
975
network.ifr_flags |= IFF_UP;
976
ret = ioctl(sd, SIOCSIFFLAGS, &network);
978
perror("ioctl SIOCSIFFLAGS");
979
exitcode = EXIT_FAILURE;
980
ret = klogctl(7, NULL, 0);
987
/* sleep checking until interface is running */
988
for(int i=0; i < delay * 4; i++){
989
ret = ioctl(sd, SIOCGIFFLAGS, &network);
991
perror("ioctl SIOCGIFFLAGS");
992
} else if(network.ifr_flags & IFF_RUNNING){
995
struct timespec sleeptime = { .tv_nsec = 250000000 };
996
nanosleep(&sleeptime, NULL);
998
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1002
/* Restores kernel loglevel to default */
1003
ret = klogctl(7, NULL, 0);
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");
1014
829
perror("setgid");
1022
ret = init_gnutls_global(&mc, pubkey, seckey);
1024
fprintf(stderr, "init_gnutls_global failed\n");
1025
exitcode = EXIT_FAILURE;
1028
gnutls_initialized = true;
1031
if(mkdtemp(tempdir) == NULL){
1035
tempdir_created = true;
1037
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1038
fprintf(stderr, "init_gpgme failed\n");
1039
exitcode = EXIT_FAILURE;
1042
gpgme_initialized = true;
1045
832
if_index = (AvahiIfIndex) if_nametoindex(interface);
1046
833
if(if_index == 0){
1047
834
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1048
exitcode = EXIT_FAILURE;
1052
838
if(connect_to != NULL){