36
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
37
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
41
39
#include <stdint.h> /* uint16_t, uint32_t */
42
40
#include <stddef.h> /* NULL, size_t, ssize_t */
43
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, false, true */
43
#include <stdbool.h> /* bool, true */
46
44
#include <string.h> /* memset(), strcmp(), strlen(),
47
45
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
46
#include <sys/ioctl.h> /* ioctl */
49
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
48
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, uid_t, gid_t, open(),
53
#include <sys/stat.h> /* open() */
49
SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
54
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
inet_pton(), connect() */
56
#include <fcntl.h> /* open() */
57
#include <dirent.h> /* opendir(), struct dirent, readdir()
59
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
53
struct in6_addr, inet_pton(),
60
55
#include <assert.h> /* assert() */
61
56
#include <errno.h> /* perror(), errno */
62
#include <time.h> /* nanosleep(), time() */
57
#include <time.h> /* time() */
63
58
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
64
59
SIOCSIFFLAGS, if_indextoname(),
65
60
if_nametoindex(), IF_NAMESIZE */
66
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
67
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
69
61
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
62
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
72
65
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, or, and */
66
#include <iso646.h> /* not, and */
74
67
#include <argp.h> /* struct argp_option, error_t, struct
75
68
argp_state, struct argp,
76
69
argp_parse(), ARGP_KEY_ARG,
77
70
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
79
#include <sys/klog.h> /* klogctl() */
83
73
/* All Avahi types, constants and functions
135
* Decrypt OpenPGP data using keyrings in HOMEDIR.
136
* Returns -1 on error
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
153
const char *pubkey, const char *tempdir){
138
static ssize_t pgp_packet_decrypt (const char *cryptotext,
141
const char *homedir){
142
gpgme_data_t dh_crypto, dh_plain;
155
144
gpgme_error_t rc;
146
size_t plaintext_capacity = 0;
147
ssize_t plaintext_length = 0;
156
148
gpgme_engine_info_t engine_info;
160
* Helper function to insert pub and seckey to the engine keyring.
162
bool import_key(const char *filename){
164
gpgme_data_t pgp_data;
166
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
172
rc = gpgme_data_new_from_fd(&pgp_data, fd);
173
if(rc != GPG_ERR_NO_ERROR){
174
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
179
rc = gpgme_op_import(mc->ctx, pgp_data);
180
if(rc != GPG_ERR_NO_ERROR){
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
186
ret = (int)TEMP_FAILURE_RETRY(close(fd));
190
gpgme_data_release(pgp_data);
195
fprintf(stderr, "Initialize gpgme\n");
151
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
199
155
gpgme_check_version(NULL);
200
156
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
201
if(rc != GPG_ERR_NO_ERROR){
157
if (rc != GPG_ERR_NO_ERROR){
202
158
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
159
gpgme_strsource(rc), gpgme_strerror(rc));
207
/* Set GPGME home directory for the OpenPGP engine only */
208
rc = gpgme_get_engine_info(&engine_info);
209
if(rc != GPG_ERR_NO_ERROR){
163
/* Set GPGME home directory for the OpenPGP engine only */
164
rc = gpgme_get_engine_info (&engine_info);
165
if (rc != GPG_ERR_NO_ERROR){
210
166
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
167
gpgme_strsource(rc), gpgme_strerror(rc));
214
170
while(engine_info != NULL){
215
171
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
216
172
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
217
engine_info->file_name, tempdir);
173
engine_info->file_name, homedir);
220
176
engine_info = engine_info->next;
222
178
if(engine_info == NULL){
223
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
227
/* Create new GPGME "context" */
228
rc = gpgme_new(&(mc->ctx));
229
if(rc != GPG_ERR_NO_ERROR){
230
fprintf(stderr, "bad gpgme_new: %s: %s\n",
231
gpgme_strsource(rc), gpgme_strerror(rc));
235
if(not import_key(pubkey) or not import_key(seckey)){
243
* Decrypt OpenPGP data.
244
* Returns -1 on error
246
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
247
const char *cryptotext,
250
gpgme_data_t dh_crypto, dh_plain;
253
size_t plaintext_capacity = 0;
254
ssize_t plaintext_length = 0;
257
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
179
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
260
183
/* Create new GPGME data buffer from memory cryptotext */
261
184
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
263
if(rc != GPG_ERR_NO_ERROR){
186
if (rc != GPG_ERR_NO_ERROR){
264
187
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
265
188
gpgme_strsource(rc), gpgme_strerror(rc));
748
/* Combines file name and path and returns the malloced new
749
string. some sane checks could/should be added */
750
static char *combinepath(const char *first, const char *second){
752
int ret = asprintf(&tmp, "%s/%s", first, second);
873
760
int main(int argc, char *argv[]){
874
AvahiSServiceBrowser *sb = NULL;
879
int exitcode = EXIT_SUCCESS;
880
const char *interface = "eth0";
881
struct ifreq network;
885
char *connect_to = NULL;
886
char tempdir[] = "/tmp/mandosXXXXXX";
887
bool tempdir_created = false;
888
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
889
const char *seckey = PATHDIR "/" SECKEY;
890
const char *pubkey = PATHDIR "/" PUBKEY;
892
mandos_context mc = { .simple_poll = NULL, .server = NULL,
893
.dh_bits = 1024, .priority = "SECURE256"
894
":!CTYPE-X.509:+CTYPE-OPENPGP" };
895
bool gnutls_initialized = false;
896
bool gpgme_initialized = false;
900
struct argp_option options[] = {
901
{ .name = "debug", .key = 128,
902
.doc = "Debug mode", .group = 3 },
903
{ .name = "connect", .key = 'c',
904
.arg = "ADDRESS:PORT",
905
.doc = "Connect directly to a specific Mandos server",
907
{ .name = "interface", .key = 'i',
909
.doc = "Network interface that will be used to search for"
912
{ .name = "seckey", .key = 's',
914
.doc = "OpenPGP secret key file base name",
916
{ .name = "pubkey", .key = 'p',
918
.doc = "OpenPGP public key file base name",
920
{ .name = "dh-bits", .key = 129,
922
.doc = "Bit length of the prime number used in the"
923
" Diffie-Hellman key exchange",
925
{ .name = "priority", .key = 130,
927
.doc = "GnuTLS priority string for the TLS handshake",
929
{ .name = "delay", .key = 131,
931
.doc = "Maximum delay to wait for interface startup",
936
error_t parse_opt(int key, char *arg,
937
struct argp_state *state){
939
case 128: /* --debug */
942
case 'c': /* --connect */
945
case 'i': /* --interface */
948
case 's': /* --seckey */
951
case 'p': /* --pubkey */
954
case 129: /* --dh-bits */
955
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
956
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
957
or arg[numchars] != '\0'){
958
fprintf(stderr, "Bad number of DH bits\n");
961
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
963
case 130: /* --priority */
966
case 131: /* --delay */
967
ret = sscanf(arg, "%lf%n", &delay, &numchars);
968
if(ret < 1 or arg[numchars] != '\0'){
969
fprintf(stderr, "Bad delay\n");
978
return ARGP_ERR_UNKNOWN;
983
struct argp argp = { .options = options, .parser = parse_opt,
985
.doc = "Mandos client -- Get and decrypt"
986
" passwords from a Mandos server" };
987
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
988
if(ret == ARGP_ERR_UNKNOWN){
989
fprintf(stderr, "Unknown error while parsing arguments\n");
990
exitcode = EXIT_FAILURE;
995
/* If the interface is down, bring it up */
996
if(interface[0] != '\0'){
998
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
999
messages to mess up the prompt */
1000
ret = klogctl(8, NULL, 5);
1001
bool restore_loglevel = true;
1003
restore_loglevel = false;
1008
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1011
exitcode = EXIT_FAILURE;
1013
if(restore_loglevel){
1014
ret = klogctl(7, NULL, 0);
1022
strcpy(network.ifr_name, interface);
1023
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1025
perror("ioctl SIOCGIFFLAGS");
1027
if(restore_loglevel){
1028
ret = klogctl(7, NULL, 0);
1034
exitcode = EXIT_FAILURE;
1037
if((network.ifr_flags & IFF_UP) == 0){
1038
network.ifr_flags |= IFF_UP;
1039
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1041
perror("ioctl SIOCSIFFLAGS");
1042
exitcode = EXIT_FAILURE;
1044
if(restore_loglevel){
1045
ret = klogctl(7, NULL, 0);
761
AvahiSServiceBrowser *sb = NULL;
764
int exitcode = EXIT_SUCCESS;
765
const char *interface = "eth0";
766
struct ifreq network;
770
char *connect_to = NULL;
771
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
772
char *pubkeyfilename = NULL;
773
char *seckeyfilename = NULL;
774
const char *pubkeyname = "pubkey.txt";
775
const char *seckeyname = "seckey.txt";
776
mandos_context mc = { .simple_poll = NULL, .server = NULL,
777
.dh_bits = 1024, .priority = "SECURE256"};
778
bool gnutls_initalized = false;
781
struct argp_option options[] = {
782
{ .name = "debug", .key = 128,
783
.doc = "Debug mode", .group = 3 },
784
{ .name = "connect", .key = 'c',
786
.doc = "Connect directly to a sepcified mandos server",
788
{ .name = "interface", .key = 'i',
790
.doc = "Interface that Avahi will conntect through",
792
{ .name = "keydir", .key = 'd',
794
.doc = "Directory where the openpgp keyring is",
796
{ .name = "seckey", .key = 's',
798
.doc = "Secret openpgp key for gnutls authentication",
800
{ .name = "pubkey", .key = 'p',
802
.doc = "Public openpgp key for gnutls authentication",
804
{ .name = "dh-bits", .key = 129,
806
.doc = "dh-bits to use in gnutls communication",
808
{ .name = "priority", .key = 130,
810
.doc = "GNUTLS priority", .group = 1 },
815
error_t parse_opt (int key, char *arg,
816
struct argp_state *state) {
817
/* Get the INPUT argument from `argp_parse', which we know is
818
a pointer to our plugin list pointer. */
840
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
854
return ARGP_ERR_UNKNOWN;
1054
/* sleep checking until interface is running */
1055
for(int i=0; i < delay * 4; i++){
859
struct argp argp = { .options = options, .parser = parse_opt,
861
.doc = "Mandos client -- Get and decrypt"
862
" passwords from mandos server" };
863
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
864
if (ret == ARGP_ERR_UNKNOWN){
865
fprintf(stderr, "Unknown error while parsing arguments\n");
866
exitcode = EXIT_FAILURE;
871
pubkeyfilename = combinepath(keydir, pubkeyname);
872
if (pubkeyfilename == NULL){
873
perror("combinepath");
874
exitcode = EXIT_FAILURE;
878
seckeyfilename = combinepath(keydir, seckeyname);
879
if (seckeyfilename == NULL){
880
perror("combinepath");
881
exitcode = EXIT_FAILURE;
885
ret = init_gnutls_global(&mc, pubkeyfilename, seckeyfilename);
887
fprintf(stderr, "init_gnutls_global failed\n");
888
exitcode = EXIT_FAILURE;
891
gnutls_initalized = true;
894
/* If the interface is down, bring it up */
896
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
899
exitcode = EXIT_FAILURE;
902
strcpy(network.ifr_name, interface);
1056
903
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1058
905
perror("ioctl SIOCGIFFLAGS");
1059
} else if(network.ifr_flags & IFF_RUNNING){
1062
struct timespec sleeptime = { .tv_nsec = 250000000 };
1063
ret = nanosleep(&sleeptime, NULL);
1064
if(ret == -1 and errno != EINTR){
1065
perror("nanosleep");
1068
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1073
if(restore_loglevel){
1074
/* Restores kernel loglevel to default */
1075
ret = klogctl(7, NULL, 0);
1097
ret = init_gnutls_global(&mc, pubkey, seckey);
1099
fprintf(stderr, "init_gnutls_global failed\n");
1100
exitcode = EXIT_FAILURE;
1103
gnutls_initialized = true;
1106
if(mkdtemp(tempdir) == NULL){
1110
tempdir_created = true;
1112
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1113
fprintf(stderr, "init_gpgme failed\n");
1114
exitcode = EXIT_FAILURE;
1117
gpgme_initialized = true;
1120
if(interface[0] != '\0'){
906
exitcode = EXIT_FAILURE;
909
if((network.ifr_flags & IFF_UP) == 0){
910
network.ifr_flags |= IFF_UP;
911
ret = ioctl(sd, SIOCSIFFLAGS, &network);
913
perror("ioctl SIOCSIFFLAGS");
914
exitcode = EXIT_FAILURE;
1121
934
if_index = (AvahiIfIndex) if_nametoindex(interface);
1122
935
if(if_index == 0){
1123
936
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1124
exitcode = EXIT_FAILURE;
1129
if(connect_to != NULL){
1130
/* Connect directly, do not use Zeroconf */
1131
/* (Mainly meant for debugging) */
1132
char *address = strrchr(connect_to, ':');
1133
if(address == NULL){
1134
fprintf(stderr, "No colon in address\n");
1135
exitcode = EXIT_FAILURE;
1139
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1140
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1141
or address[numchars+1] != '\0'){
1142
fprintf(stderr, "Bad port number\n");
1143
exitcode = EXIT_FAILURE;
1146
port = (uint16_t)tmpmax;
1148
address = connect_to;
1149
/* Colon in address indicates IPv6 */
1151
if(strchr(address, ':') != NULL){
1156
ret = start_mandos_communication(address, port, if_index, &mc,
1159
exitcode = EXIT_FAILURE;
1161
exitcode = EXIT_SUCCESS;
1167
avahi_set_log_function(empty_log);
1170
/* Initialize the pseudo-RNG for Avahi */
1171
srand((unsigned int) time(NULL));
1173
/* Allocate main Avahi loop object */
1174
mc.simple_poll = avahi_simple_poll_new();
1175
if(mc.simple_poll == NULL){
1176
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1177
exitcode = EXIT_FAILURE;
1182
AvahiServerConfig config;
1183
/* Do not publish any local Zeroconf records */
1184
avahi_server_config_init(&config);
1185
config.publish_hinfo = 0;
1186
config.publish_addresses = 0;
1187
config.publish_workstation = 0;
1188
config.publish_domain = 0;
1190
/* Allocate a new server */
1191
mc.server = avahi_server_new(avahi_simple_poll_get
1192
(mc.simple_poll), &config, NULL,
1195
/* Free the Avahi configuration data */
1196
avahi_server_config_free(&config);
1199
/* Check if creating the Avahi server object succeeded */
1200
if(mc.server == NULL){
1201
fprintf(stderr, "Failed to create Avahi server: %s\n",
1202
avahi_strerror(error));
1203
exitcode = EXIT_FAILURE;
1207
/* Create the Avahi service browser */
1208
sb = avahi_s_service_browser_new(mc.server, if_index,
1209
AVAHI_PROTO_INET6, "_mandos._tcp",
1210
NULL, 0, browse_callback, &mc);
1212
fprintf(stderr, "Failed to create service browser: %s\n",
1213
avahi_strerror(avahi_server_errno(mc.server)));
1214
exitcode = EXIT_FAILURE;
1218
/* Run the main loop */
1221
fprintf(stderr, "Starting Avahi loop search\n");
1224
avahi_simple_poll_loop(mc.simple_poll);
940
if(connect_to != NULL){
941
/* Connect directly, do not use Zeroconf */
942
/* (Mainly meant for debugging) */
943
char *address = strrchr(connect_to, ':');
945
fprintf(stderr, "No colon in address\n");
946
exitcode = EXIT_FAILURE;
950
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
952
perror("Bad port number");
953
exitcode = EXIT_FAILURE;
957
address = connect_to;
958
ret = start_mandos_communication(address, port, if_index, &mc);
960
exitcode = EXIT_FAILURE;
962
exitcode = EXIT_SUCCESS;
968
avahi_set_log_function(empty_log);
971
/* Initialize the pseudo-RNG for Avahi */
972
srand((unsigned int) time(NULL));
974
/* Allocate main Avahi loop object */
975
mc.simple_poll = avahi_simple_poll_new();
976
if (mc.simple_poll == NULL) {
977
fprintf(stderr, "Avahi: Failed to create simple poll"
979
exitcode = EXIT_FAILURE;
984
AvahiServerConfig config;
985
/* Do not publish any local Zeroconf records */
986
avahi_server_config_init(&config);
987
config.publish_hinfo = 0;
988
config.publish_addresses = 0;
989
config.publish_workstation = 0;
990
config.publish_domain = 0;
992
/* Allocate a new server */
993
mc.server = avahi_server_new(avahi_simple_poll_get
994
(mc.simple_poll), &config, NULL,
997
/* Free the Avahi configuration data */
998
avahi_server_config_free(&config);
1001
/* Check if creating the Avahi server object succeeded */
1002
if (mc.server == NULL) {
1003
fprintf(stderr, "Failed to create Avahi server: %s\n",
1004
avahi_strerror(error));
1005
exitcode = EXIT_FAILURE;
1009
/* Create the Avahi service browser */
1010
sb = avahi_s_service_browser_new(mc.server, if_index,
1012
"_mandos._tcp", NULL, 0,
1013
browse_callback, &mc);
1015
fprintf(stderr, "Failed to create service browser: %s\n",
1016
avahi_strerror(avahi_server_errno(mc.server)));
1017
exitcode = EXIT_FAILURE;
1021
/* Run the main loop */
1024
fprintf(stderr, "Starting Avahi loop search\n");
1027
avahi_simple_poll_loop(mc.simple_poll);
1229
fprintf(stderr, "%s exiting\n", argv[0]);
1232
/* Cleanup things */
1234
avahi_s_service_browser_free(sb);
1236
if(mc.server != NULL)
1237
avahi_server_free(mc.server);
1239
if(mc.simple_poll != NULL)
1240
avahi_simple_poll_free(mc.simple_poll);
1242
if(gnutls_initialized){
1243
gnutls_certificate_free_credentials(mc.cred);
1244
gnutls_global_deinit();
1245
gnutls_dh_params_deinit(mc.dh_params);
1248
if(gpgme_initialized){
1249
gpgme_release(mc.ctx);
1252
/* Removes the temp directory used by GPGME */
1253
if(tempdir_created){
1255
struct dirent *direntry;
1256
d = opendir(tempdir);
1258
if(errno != ENOENT){
1263
direntry = readdir(d);
1264
if(direntry == NULL){
1267
/* Skip "." and ".." */
1268
if(direntry->d_name[0] == '.'
1269
and (direntry->d_name[1] == '\0'
1270
or (direntry->d_name[1] == '.'
1271
and direntry->d_name[2] == '\0'))){
1274
char *fullname = NULL;
1275
ret = asprintf(&fullname, "%s/%s", tempdir,
1281
ret = remove(fullname);
1283
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1290
ret = rmdir(tempdir);
1291
if(ret == -1 and errno != ENOENT){
1032
fprintf(stderr, "%s exiting\n", argv[0]);
1035
/* Cleanup things */
1037
avahi_s_service_browser_free(sb);
1039
if (mc.server != NULL)
1040
avahi_server_free(mc.server);
1042
if (mc.simple_poll != NULL)
1043
avahi_simple_poll_free(mc.simple_poll);
1044
free(pubkeyfilename);
1045
free(seckeyfilename);
1047
if (gnutls_initalized){
1048
gnutls_certificate_free_credentials(mc.cred);
1049
gnutls_global_deinit ();