32
32
#define _LARGEFILE_SOURCE
33
33
#define _FILE_OFFSET_BITS 64
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
37
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
39
#include <stdint.h> /* uint16_t, uint32_t */
40
40
#include <stddef.h> /* NULL, size_t, ssize_t */
41
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
43
#include <stdbool.h> /* bool, true */
44
44
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), memcpy(), strcpy() */
45
strerror(), asprintf(), strcpy() */
46
46
#include <sys/ioctl.h> /* ioctl */
47
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
48
sockaddr_in6, PF_INET6,
49
49
SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
50
uid_t, gid_t, open(), opendir(), DIR */
51
#include <sys/stat.h> /* open() */
52
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
53
struct in6_addr, inet_pton(),
55
#include <fcntl.h> /* open() */
56
#include <dirent.h> /* opendir(), struct dirent, readdir() */
57
#include <inttypes.h> /* PRIu16 */
55
58
#include <assert.h> /* assert() */
56
59
#include <errno.h> /* perror(), errno */
57
60
#include <time.h> /* time() */
58
61
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
59
62
SIOCSIFFLAGS, if_indextoname(),
60
63
if_nametoindex(), IF_NAMESIZE */
64
#include <netinet/in.h>
61
65
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
62
66
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
65
68
#include <arpa/inet.h> /* inet_pton(), htons */
66
69
#include <iso646.h> /* not, and */
67
70
#include <argp.h> /* struct argp_option, error_t, struct
89
93
GNUTLS_OPENPGP_FMT_BASE64 */
92
#include <gpgme.h> /* All GPGME types, constants and functions
96
#include <gpgme.h> /* All GPGME types, constants and
94
99
GPGME_PROTOCOL_OpenPGP,
97
102
#define BUFFER_SIZE 256
104
#define PATHDIR "/conf/conf.d/mandos"
105
#define SECKEY "seckey.txt"
106
#define PUBKEY "pubkey.txt"
99
108
bool debug = false;
100
static const char *keydir = "/conf/conf.d/mandos";
101
109
static const char mandos_protocol_version[] = "1";
102
const char *argp_program_version = "password-request 1.0";
110
const char *argp_program_version = "mandos-client " VERSION;
103
111
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
105
113
/* Used for passing in values through the Avahi callback functions */
133
* Decrypt OpenPGP data using keyrings in HOMEDIR.
134
* Returns -1 on error
136
static ssize_t pgp_packet_decrypt (const char *cryptotext,
139
const char *homedir){
140
gpgme_data_t dh_crypto, dh_plain;
144
static bool init_gpgme(mandos_context *mc, const char *seckey,
145
const char *pubkey, const char *tempdir){
142
147
gpgme_error_t rc;
144
size_t plaintext_capacity = 0;
145
ssize_t plaintext_length = 0;
146
148
gpgme_engine_info_t engine_info;
152
* Helper function to insert pub and seckey to the enigne keyring.
154
bool import_key(const char *filename){
156
gpgme_data_t pgp_data;
158
fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
164
rc = gpgme_data_new_from_fd(&pgp_data, fd);
165
if (rc != GPG_ERR_NO_ERROR){
166
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
167
gpgme_strsource(rc), gpgme_strerror(rc));
171
rc = gpgme_op_import(mc->ctx, pgp_data);
172
if (rc != GPG_ERR_NO_ERROR){
173
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
174
gpgme_strsource(rc), gpgme_strerror(rc));
178
ret = TEMP_FAILURE_RETRY(close(fd));
182
gpgme_data_release(pgp_data);
149
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
187
fprintf(stderr, "Initialize gpgme\n");
155
193
if (rc != GPG_ERR_NO_ERROR){
156
194
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
157
195
gpgme_strsource(rc), gpgme_strerror(rc));
161
/* Set GPGME home directory for the OpenPGP engine only */
199
/* Set GPGME home directory for the OpenPGP engine only */
162
200
rc = gpgme_get_engine_info (&engine_info);
163
201
if (rc != GPG_ERR_NO_ERROR){
164
202
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
165
203
gpgme_strsource(rc), gpgme_strerror(rc));
168
206
while(engine_info != NULL){
169
207
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
170
208
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
171
engine_info->file_name, homedir);
209
engine_info->file_name, tempdir);
174
212
engine_info = engine_info->next;
176
214
if(engine_info == NULL){
177
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
215
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
219
/* Create new GPGME "context" */
220
rc = gpgme_new(&(mc->ctx));
221
if (rc != GPG_ERR_NO_ERROR){
222
fprintf(stderr, "bad gpgme_new: %s: %s\n",
223
gpgme_strsource(rc), gpgme_strerror(rc));
227
if (not import_key(pubkey) or not import_key(seckey)){
235
* Decrypt OpenPGP data.
236
* Returns -1 on error
238
static ssize_t pgp_packet_decrypt (const mandos_context *mc,
239
const char *cryptotext,
242
gpgme_data_t dh_crypto, dh_plain;
245
size_t plaintext_capacity = 0;
246
ssize_t plaintext_length = 0;
249
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
181
252
/* Create new GPGME data buffer from memory cryptotext */
199
/* Create new GPGME "context" */
200
rc = gpgme_new(&ctx);
201
if (rc != GPG_ERR_NO_ERROR){
202
fprintf(stderr, "bad gpgme_new: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
204
plaintext_length = -1;
208
270
/* Decrypt data from the cryptotext data buffer to the plaintext
210
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
272
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
211
273
if (rc != GPG_ERR_NO_ERROR){
212
274
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
213
275
gpgme_strsource(rc), gpgme_strerror(rc));
214
276
plaintext_length = -1;
278
gpgme_decrypt_result_t result;
279
result = gpgme_op_decrypt_result(mc->ctx);
281
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
283
fprintf(stderr, "Unsupported algorithm: %s\n",
284
result->unsupported_algorithm);
285
fprintf(stderr, "Wrong key usage: %u\n",
286
result->wrong_key_usage);
287
if(result->file_name != NULL){
288
fprintf(stderr, "File name: %s\n", result->file_name);
290
gpgme_recipient_t recipient;
291
recipient = result->recipients;
293
while(recipient != NULL){
294
fprintf(stderr, "Public key algorithm: %s\n",
295
gpgme_pubkey_algo_name(recipient->pubkey_algo));
296
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
297
fprintf(stderr, "Secret key available: %s\n",
298
recipient->status == GPG_ERR_NO_SECKEY
300
recipient = recipient->next;
215
305
goto decrypt_end;
219
309
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
223
gpgme_decrypt_result_t result;
224
result = gpgme_op_decrypt_result(ctx);
226
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
228
fprintf(stderr, "Unsupported algorithm: %s\n",
229
result->unsupported_algorithm);
230
fprintf(stderr, "Wrong key usage: %u\n",
231
result->wrong_key_usage);
232
if(result->file_name != NULL){
233
fprintf(stderr, "File name: %s\n", result->file_name);
235
gpgme_recipient_t recipient;
236
recipient = result->recipients;
238
while(recipient != NULL){
239
fprintf(stderr, "Public key algorithm: %s\n",
240
gpgme_pubkey_algo_name(recipient->pubkey_algo));
241
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
242
fprintf(stderr, "Secret key available: %s\n",
243
recipient->status == GPG_ERR_NO_SECKEY
245
recipient = recipient->next;
251
312
/* Seek back to the beginning of the GPGME plaintext data buffer */
252
313
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
253
perror("pgpme_data_seek");
314
perror("gpgme_data_seek");
254
315
plaintext_length = -1;
255
316
goto decrypt_end;
339
400
/* OpenPGP credentials */
340
401
gnutls_certificate_allocate_credentials(&mc->cred);
341
402
if (ret != GNUTLS_E_SUCCESS){
342
fprintf (stderr, "GnuTLS memory error: %s\n",
403
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
343
405
safer_gnutls_strerror(ret));
344
406
gnutls_global_deinit ();
349
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
350
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
411
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
412
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
354
416
ret = gnutls_certificate_set_openpgp_key_file
355
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
417
(mc->cred, pubkeyfilename, seckeyfilename,
418
GNUTLS_OPENPGP_FMT_BASE64);
356
419
if (ret != GNUTLS_E_SUCCESS) {
358
421
"Error[%d] while reading the OpenPGP key pair ('%s',"
359
" '%s')\n", ret, pubkeyfile, seckeyfile);
360
fprintf(stdout, "The GnuTLS error is: %s\n",
422
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
423
fprintf(stderr, "The GnuTLS error is: %s\n",
361
424
safer_gnutls_strerror(ret));
743
/* Combines file name and path and returns the malloced new
744
string. some sane checks could/should be added */
745
static const char *combinepath(const char *first, const char *second){
746
size_t f_len = strlen(first);
747
size_t s_len = strlen(second);
748
char *tmp = malloc(f_len + s_len + 2);
753
memcpy(tmp, first, f_len); /* Spurious warning */
757
memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */
759
tmp[f_len + 1 + s_len] = '\0';
764
810
int main(int argc, char *argv[]){
765
811
AvahiSServiceBrowser *sb = NULL;
774
820
char *connect_to = NULL;
821
char tempdir[] = "/tmp/mandosXXXXXX";
775
822
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
776
const char *pubkeyfile = "pubkey.txt";
777
const char *seckeyfile = "seckey.txt";
823
const char *seckey = PATHDIR "/" SECKEY;
824
const char *pubkey = PATHDIR "/" PUBKEY;
778
826
mandos_context mc = { .simple_poll = NULL, .server = NULL,
779
.dh_bits = 1024, .priority = "SECURE256"};
827
.dh_bits = 1024, .priority = "SECURE256"
828
":!CTYPE-X.509:+CTYPE-OPENPGP" };
780
829
bool gnutls_initalized = false;
830
bool gpgme_initalized = false;
783
833
struct argp_option options[] = {
784
834
{ .name = "debug", .key = 128,
785
835
.doc = "Debug mode", .group = 3 },
786
836
{ .name = "connect", .key = 'c',
788
.doc = "Connect directly to a sepcified mandos server",
837
.arg = "ADDRESS:PORT",
838
.doc = "Connect directly to a specific Mandos server",
790
840
{ .name = "interface", .key = 'i',
792
.doc = "Interface that Avahi will conntect through",
794
{ .name = "keydir", .key = 'd',
796
.doc = "Directory where the openpgp keyring is",
842
.doc = "Interface that will be used to search for Mandos"
798
845
{ .name = "seckey", .key = 's',
800
.doc = "Secret openpgp key for gnutls authentication",
847
.doc = "OpenPGP secret key file base name",
802
849
{ .name = "pubkey", .key = 'p',
804
.doc = "Public openpgp key for gnutls authentication",
851
.doc = "OpenPGP public key file base name",
806
853
{ .name = "dh-bits", .key = 129,
808
.doc = "dh-bits to use in gnutls communication",
855
.doc = "Bit length of the prime number used in the"
856
" Diffie-Hellman key exchange",
810
858
{ .name = "priority", .key = 130,
812
.doc = "GNUTLS priority", .group = 1 },
860
.doc = "GnuTLS priority string for the TLS handshake",
817
865
error_t parse_opt (int key, char *arg,
818
866
struct argp_state *state) {
819
867
/* Get the INPUT argument from `argp_parse', which we know is
820
868
a pointer to our plugin list pointer. */
870
case 128: /* --debug */
873
case 'c': /* --connect */
826
874
connect_to = arg;
876
case 'i': /* --interface */
879
case 's': /* --seckey */
882
case 'p': /* --pubkey */
885
case 129: /* --dh-bits */
842
887
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
845
890
exit(EXIT_FAILURE);
893
case 130: /* --priority */
849
894
mc.priority = arg;
851
896
case ARGP_KEY_ARG:
852
897
argp_usage (state);
857
901
return ARGP_ERR_UNKNOWN;
862
906
struct argp argp = { .options = options, .parser = parse_opt,
864
908
.doc = "Mandos client -- Get and decrypt"
865
" passwords from mandos server" };
909
" passwords from a Mandos server" };
866
910
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
867
911
if (ret == ARGP_ERR_UNKNOWN){
868
912
fprintf(stderr, "Unknown error while parsing arguments\n");
932
958
perror("setgid");
961
ret = init_gnutls_global(&mc, pubkey, seckey);
963
fprintf(stderr, "init_gnutls_global failed\n");
964
exitcode = EXIT_FAILURE;
967
gnutls_initalized = true;
970
if(mkdtemp(tempdir) == NULL){
976
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
977
fprintf(stderr, "gpgme_initalized failed\n");
978
exitcode = EXIT_FAILURE;
981
gpgme_initalized = true;
935
984
if_index = (AvahiIfIndex) if_nametoindex(interface);
936
985
if(if_index == 0){
937
986
fprintf(stderr, "No such interface: \"%s\"\n", interface);
989
1038
config.publish_addresses = 0;
990
1039
config.publish_workstation = 0;
991
1040
config.publish_domain = 0;
993
1042
/* Allocate a new server */
994
1043
mc.server = avahi_server_new(avahi_simple_poll_get
995
1044
(mc.simple_poll), &config, NULL,
998
1047
/* Free the Avahi configuration data */
999
1048
avahi_server_config_free(&config);
1040
1089
if (mc.server != NULL)
1041
1090
avahi_server_free(mc.server);
1043
1092
if (mc.simple_poll != NULL)
1044
1093
avahi_simple_poll_free(mc.simple_poll);
1048
1095
if (gnutls_initalized){
1049
1096
gnutls_certificate_free_credentials(mc.cred);
1050
1097
gnutls_global_deinit ();
1098
gnutls_dh_params_deinit(mc.dh_params);
1101
if(gpgme_initalized){
1102
gpgme_release(mc.ctx);
1105
/* Removes the temp directory used by GPGME */
1106
if(tempdir[0] != '\0'){
1108
struct dirent *direntry;
1109
d = opendir(tempdir);
1114
direntry = readdir(d);
1115
if(direntry == NULL){
1118
if (direntry->d_type == DT_REG){
1119
char *fullname = NULL;
1120
ret = asprintf(&fullname, "%s/%s", tempdir,
1126
ret = unlink(fullname);
1128
fprintf(stderr, "unlink(\"%s\"): %s",
1129
fullname, strerror(errno));
1136
ret = rmdir(tempdir);
1053
1142
return exitcode;