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(),
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(), DIR */
52
#include <sys/stat.h> /* open() */
53
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
54
struct in6_addr, inet_pton(),
56
#include <fcntl.h> /* open() */
57
#include <dirent.h> /* opendir(), struct dirent, readdir() */
58
#include <inttypes.h> /* PRIu16 */
59
#include <assert.h> /* assert() */
60
#include <errno.h> /* perror(), errno */
61
#include <time.h> /* time() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
62
44
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
63
SIOCSIFFLAGS, if_indextoname(),
64
if_nametoindex(), IF_NAMESIZE */
65
#include <netinet/in.h>
66
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
67
getuid(), getgid(), setuid(),
69
#include <arpa/inet.h> /* inet_pton(), htons */
70
#include <iso646.h> /* not, and */
71
#include <argp.h> /* struct argp_option, error_t, struct
72
argp_state, struct argp,
73
argp_parse(), ARGP_KEY_ARG,
74
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
77
/* All Avahi types, constants and functions
80
47
#include <avahi-core/core.h>
81
48
#include <avahi-core/lookup.h>
82
49
#include <avahi-core/log.h>
84
51
#include <avahi-common/malloc.h>
85
52
#include <avahi-common/error.h>
88
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
91
init_gnutls_session(),
93
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
94
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,
97
#include <gpgme.h> /* All GPGME types, constants and
100
GPGME_PROTOCOL_OpenPGP,
72
#include <errno.h> /* perror() */
103
75
#define BUFFER_SIZE 256
105
#define PATHDIR "/conf/conf.d/mandos"
106
#define SECKEY "seckey.txt"
107
#define PUBKEY "pubkey.txt"
109
77
bool debug = false;
78
static const char *keydir = "/conf/conf.d/mandos";
110
79
static const char mandos_protocol_version[] = "1";
111
const char *argp_program_version = "mandos-client " VERSION;
80
const char *argp_program_version = "mandosclient 0.9";
112
81
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
114
83
/* Used for passing in values through the Avahi callback functions */
111
* Decrypt OpenPGP data using keyrings in HOMEDIR.
112
* Returns -1 on error
145
static bool init_gpgme(mandos_context *mc, const char *seckey,
146
const char *pubkey, const char *tempdir){
114
static ssize_t pgp_packet_decrypt (const char *cryptotext,
117
const char *homedir){
118
gpgme_data_t dh_crypto, dh_plain;
148
120
gpgme_error_t rc;
122
size_t plaintext_capacity = 0;
123
ssize_t plaintext_length = 0;
149
124
gpgme_engine_info_t engine_info;
153
* Helper function to insert pub and seckey to the enigne keyring.
155
bool import_key(const char *filename){
157
gpgme_data_t pgp_data;
159
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
165
rc = gpgme_data_new_from_fd(&pgp_data, fd);
166
if (rc != GPG_ERR_NO_ERROR){
167
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
168
gpgme_strsource(rc), gpgme_strerror(rc));
172
rc = gpgme_op_import(mc->ctx, pgp_data);
173
if (rc != GPG_ERR_NO_ERROR){
174
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
179
ret = (int)TEMP_FAILURE_RETRY(close(fd));
183
gpgme_data_release(pgp_data);
188
fprintf(stderr, "Initialize gpgme\n");
127
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
194
133
if (rc != GPG_ERR_NO_ERROR){
195
134
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
196
135
gpgme_strsource(rc), gpgme_strerror(rc));
200
/* Set GPGME home directory for the OpenPGP engine only */
139
/* Set GPGME home directory for the OpenPGP engine only */
201
140
rc = gpgme_get_engine_info (&engine_info);
202
141
if (rc != GPG_ERR_NO_ERROR){
203
142
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
204
143
gpgme_strsource(rc), gpgme_strerror(rc));
207
146
while(engine_info != NULL){
208
147
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
209
148
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
210
engine_info->file_name, tempdir);
149
engine_info->file_name, homedir);
213
152
engine_info = engine_info->next;
215
154
if(engine_info == NULL){
216
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
220
/* Create new GPGME "context" */
221
rc = gpgme_new(&(mc->ctx));
222
if (rc != GPG_ERR_NO_ERROR){
223
fprintf(stderr, "bad gpgme_new: %s: %s\n",
224
gpgme_strsource(rc), gpgme_strerror(rc));
228
if (not import_key(pubkey) or not import_key(seckey)){
236
* Decrypt OpenPGP data.
237
* Returns -1 on error
239
static ssize_t pgp_packet_decrypt (const mandos_context *mc,
240
const char *cryptotext,
243
gpgme_data_t dh_crypto, dh_plain;
246
size_t plaintext_capacity = 0;
247
ssize_t plaintext_length = 0;
250
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
155
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
253
159
/* Create new GPGME data buffer from memory cryptotext */
177
/* Create new GPGME "context" */
178
rc = gpgme_new(&ctx);
179
if (rc != GPG_ERR_NO_ERROR){
180
fprintf(stderr, "bad gpgme_new: %s: %s\n",
181
gpgme_strsource(rc), gpgme_strerror(rc));
182
plaintext_length = -1;
271
186
/* Decrypt data from the cryptotext data buffer to the plaintext
273
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
188
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
274
189
if (rc != GPG_ERR_NO_ERROR){
275
190
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
276
191
gpgme_strsource(rc), gpgme_strerror(rc));
277
192
plaintext_length = -1;
279
gpgme_decrypt_result_t result;
280
result = gpgme_op_decrypt_result(mc->ctx);
282
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
284
fprintf(stderr, "Unsupported algorithm: %s\n",
285
result->unsupported_algorithm);
286
fprintf(stderr, "Wrong key usage: %u\n",
287
result->wrong_key_usage);
288
if(result->file_name != NULL){
289
fprintf(stderr, "File name: %s\n", result->file_name);
291
gpgme_recipient_t recipient;
292
recipient = result->recipients;
294
while(recipient != NULL){
295
fprintf(stderr, "Public key algorithm: %s\n",
296
gpgme_pubkey_algo_name(recipient->pubkey_algo));
297
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
298
fprintf(stderr, "Secret key available: %s\n",
299
recipient->status == GPG_ERR_NO_SECKEY
301
recipient = recipient->next;
306
193
goto decrypt_end;
310
197
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
201
gpgme_decrypt_result_t result;
202
result = gpgme_op_decrypt_result(ctx);
204
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
206
fprintf(stderr, "Unsupported algorithm: %s\n",
207
result->unsupported_algorithm);
208
fprintf(stderr, "Wrong key usage: %d\n",
209
result->wrong_key_usage);
210
if(result->file_name != NULL){
211
fprintf(stderr, "File name: %s\n", result->file_name);
213
gpgme_recipient_t recipient;
214
recipient = result->recipients;
216
while(recipient != NULL){
217
fprintf(stderr, "Public key algorithm: %s\n",
218
gpgme_pubkey_algo_name(recipient->pubkey_algo));
219
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
220
fprintf(stderr, "Secret key available: %s\n",
221
recipient->status == GPG_ERR_NO_SECKEY
223
recipient = recipient->next;
313
229
/* Seek back to the beginning of the GPGME plaintext data buffer */
314
230
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
315
perror("gpgme_data_seek");
231
perror("pgpme_data_seek");
316
232
plaintext_length = -1;
317
233
goto decrypt_end;
377
293
static int init_gnutls_global(mandos_context *mc,
378
const char *pubkeyfilename,
379
const char *seckeyfilename){
294
const char *pubkeyfile,
295
const char *seckeyfile){
383
299
fprintf(stderr, "Initializing GnuTLS\n");
386
ret = gnutls_global_init();
387
if (ret != GNUTLS_E_SUCCESS) {
302
if ((ret = gnutls_global_init ())
303
!= GNUTLS_E_SUCCESS) {
388
304
fprintf (stderr, "GnuTLS global_init: %s\n",
389
305
safer_gnutls_strerror(ret));
401
317
/* OpenPGP credentials */
402
gnutls_certificate_allocate_credentials(&mc->cred);
403
if (ret != GNUTLS_E_SUCCESS){
404
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
318
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
319
!= GNUTLS_E_SUCCESS) {
320
fprintf (stderr, "GnuTLS memory error: %s\n",
406
321
safer_gnutls_strerror(ret));
407
322
gnutls_global_deinit ();
412
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
413
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
327
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
328
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
417
332
ret = gnutls_certificate_set_openpgp_key_file
418
(mc->cred, pubkeyfilename, seckeyfilename,
419
GNUTLS_OPENPGP_FMT_BASE64);
333
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
420
334
if (ret != GNUTLS_E_SUCCESS) {
422
336
"Error[%d] while reading the OpenPGP key pair ('%s',"
423
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
424
fprintf(stderr, "The GnuTLS error is: %s\n",
337
" '%s')\n", ret, pubkeyfile, seckeyfile);
338
fprintf(stdout, "The GnuTLS error is: %s\n",
425
339
safer_gnutls_strerror(ret));
550
463
fprintf(stderr, "Bad address: %s\n", ip);
553
to.in6.sin6_port = htons(port); /* Spurious warning */
466
to.in6.sin6_port = htons(port); /* Spurious warning */
555
468
to.in6.sin6_scope_id = (uint32_t)if_index;
558
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
471
fprintf(stderr, "Connection to: %s, port %d\n", ip, port);
560
472
char addrstr[INET6_ADDRSTRLEN] = "";
561
473
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
562
474
sizeof(addrstr)) == NULL){
636
sret = gnutls_record_recv(session, buffer+buffer_length,
546
ret = gnutls_record_recv(session, buffer+buffer_length,
643
553
case GNUTLS_E_INTERRUPTED:
644
554
case GNUTLS_E_AGAIN:
646
556
case GNUTLS_E_REHANDSHAKE:
648
ret = gnutls_handshake (session);
649
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
557
ret = gnutls_handshake (session);
651
559
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
652
560
gnutls_perror (ret);
745
649
char ip[AVAHI_ADDRESS_STR_MAX];
746
650
avahi_address_snprint(ip, sizeof(ip), address);
748
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
749
PRIu16 ") on port %d\n", name, host_name, ip,
652
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %d) on"
653
" port %d\n", name, host_name, ip, interface, port);
752
655
int ret = start_mandos_communication(ip, port, interface, mc);
754
avahi_simple_poll_quit(mc->simple_poll);
715
/* Combines file name and path and returns the malloced new
716
string. some sane checks could/should be added */
717
static const char *combinepath(const char *first, const char *second){
718
size_t f_len = strlen(first);
719
size_t s_len = strlen(second);
720
char *tmp = malloc(f_len + s_len + 2);
725
memcpy(tmp, first, f_len); /* Spurious warning */
729
memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */
731
tmp[f_len + 1 + s_len] = '\0';
812
736
int main(int argc, char *argv[]){
813
737
AvahiSServiceBrowser *sb = NULL;
822
746
char *connect_to = NULL;
823
char tempdir[] = "/tmp/mandosXXXXXX";
824
747
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
825
const char *seckey = PATHDIR "/" SECKEY;
826
const char *pubkey = PATHDIR "/" PUBKEY;
748
const char *pubkeyfile = "pubkey.txt";
749
const char *seckeyfile = "seckey.txt";
828
750
mandos_context mc = { .simple_poll = NULL, .server = NULL,
829
.dh_bits = 1024, .priority = "SECURE256"
830
":!CTYPE-X.509:+CTYPE-OPENPGP" };
751
.dh_bits = 1024, .priority = "SECURE256"};
831
752
bool gnutls_initalized = false;
832
bool gpgme_initalized = false;
835
755
struct argp_option options[] = {
836
756
{ .name = "debug", .key = 128,
837
757
.doc = "Debug mode", .group = 3 },
838
758
{ .name = "connect", .key = 'c',
839
.arg = "ADDRESS:PORT",
840
.doc = "Connect directly to a specific Mandos server",
760
.doc = "Connect directly to a sepcified mandos server",
842
762
{ .name = "interface", .key = 'i',
844
.doc = "Interface that will be used to search for Mandos"
764
.doc = "Interface that Avahi will conntect through",
766
{ .name = "keydir", .key = 'd',
768
.doc = "Directory where the openpgp keyring is",
847
770
{ .name = "seckey", .key = 's',
849
.doc = "OpenPGP secret key file base name",
772
.doc = "Secret openpgp key for gnutls authentication",
851
774
{ .name = "pubkey", .key = 'p',
853
.doc = "OpenPGP public key file base name",
776
.doc = "Public openpgp key for gnutls authentication",
855
778
{ .name = "dh-bits", .key = 129,
857
.doc = "Bit length of the prime number used in the"
858
" Diffie-Hellman key exchange",
780
.doc = "dh-bits to use in gnutls communication",
860
782
{ .name = "priority", .key = 130,
862
.doc = "GnuTLS priority string for the TLS handshake",
784
.doc = "GNUTLS priority", .group = 1 },
867
789
error_t parse_opt (int key, char *arg,
868
790
struct argp_state *state) {
869
791
/* Get the INPUT argument from `argp_parse', which we know is
870
792
a pointer to our plugin list pointer. */
872
case 128: /* --debug */
875
case 'c': /* --connect */
876
798
connect_to = arg;
878
case 'i': /* --interface */
881
case 's': /* --seckey */
884
case 'p': /* --pubkey */
887
case 129: /* --dh-bits */
889
814
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
892
817
exit(EXIT_FAILURE);
895
case 130: /* --priority */
896
821
mc.priority = arg;
898
823
case ARGP_KEY_ARG:
899
824
argp_usage (state);
903
829
return ARGP_ERR_UNKNOWN;
908
834
struct argp argp = { .options = options, .parser = parse_opt,
910
836
.doc = "Mandos client -- Get and decrypt"
911
" passwords from a Mandos server" };
912
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
913
if (ret == ARGP_ERR_UNKNOWN){
914
fprintf(stderr, "Unknown error while parsing arguments\n");
915
exitcode = EXIT_FAILURE;
920
/* If the interface is down, bring it up */
922
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
925
exitcode = EXIT_FAILURE;
928
strcpy(network.ifr_name, interface);
929
ret = ioctl(sd, SIOCGIFFLAGS, &network);
931
perror("ioctl SIOCGIFFLAGS");
932
exitcode = EXIT_FAILURE;
935
if((network.ifr_flags & IFF_UP) == 0){
936
network.ifr_flags |= IFF_UP;
937
ret = ioctl(sd, SIOCSIFFLAGS, &network);
939
perror("ioctl SIOCSIFFLAGS");
940
exitcode = EXIT_FAILURE;
944
ret = (int)TEMP_FAILURE_RETRY(close(sd));
837
" passwords from mandos server" };
838
argp_parse (&argp, argc, argv, 0, 0, NULL);
841
pubkeyfile = combinepath(keydir, pubkeyfile);
842
if (pubkeyfile == NULL){
843
perror("combinepath");
844
exitcode = EXIT_FAILURE;
848
seckeyfile = combinepath(keydir, seckeyfile);
849
if (seckeyfile == NULL){
850
perror("combinepath");
854
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
856
fprintf(stderr, "init_gnutls_global\n");
859
gnutls_initalized = true;
953
865
ret = setuid(uid);
955
867
perror("setuid");
960
872
perror("setgid");
963
ret = init_gnutls_global(&mc, pubkey, seckey);
965
fprintf(stderr, "init_gnutls_global failed\n");
966
exitcode = EXIT_FAILURE;
969
gnutls_initalized = true;
972
if(mkdtemp(tempdir) == NULL){
978
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
979
fprintf(stderr, "gpgme_initalized failed\n");
980
exitcode = EXIT_FAILURE;
983
gpgme_initalized = true;
986
875
if_index = (AvahiIfIndex) if_nametoindex(interface);
987
876
if(if_index == 0){
988
877
fprintf(stderr, "No such interface: \"%s\"\n", interface);
908
/* If the interface is down, bring it up */
910
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
913
exitcode = EXIT_FAILURE;
916
strcpy(network.ifr_name, interface); /* Spurious warning */
917
ret = ioctl(sd, SIOCGIFFLAGS, &network);
919
perror("ioctl SIOCGIFFLAGS");
920
exitcode = EXIT_FAILURE;
923
if((network.ifr_flags & IFF_UP) == 0){
924
network.ifr_flags |= IFF_UP;
925
ret = ioctl(sd, SIOCSIFFLAGS, &network);
927
perror("ioctl SIOCSIFFLAGS");
928
exitcode = EXIT_FAILURE;
1020
936
avahi_set_log_function(empty_log);
1091
1007
if (mc.server != NULL)
1092
1008
avahi_server_free(mc.server);
1094
1010
if (mc.simple_poll != NULL)
1095
1011
avahi_simple_poll_free(mc.simple_poll);
1097
1015
if (gnutls_initalized){
1098
gnutls_certificate_free_credentials(mc.cred);
1016
gnutls_certificate_free_credentials (mc.cred);
1099
1017
gnutls_global_deinit ();
1100
gnutls_dh_params_deinit(mc.dh_params);
1103
if(gpgme_initalized){
1104
gpgme_release(mc.ctx);
1107
/* Removes the temp directory used by GPGME */
1108
if(tempdir[0] != '\0'){
1110
struct dirent *direntry;
1111
d = opendir(tempdir);
1116
direntry = readdir(d);
1117
if(direntry == NULL){
1120
if (direntry->d_type == DT_REG){
1121
char *fullname = NULL;
1122
ret = asprintf(&fullname, "%s/%s", tempdir,
1128
ret = unlink(fullname);
1130
fprintf(stderr, "unlink(\"%s\"): %s",
1131
fullname, strerror(errno));
1138
ret = rmdir(tempdir);
1144
1020
return exitcode;