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";
79
const char *argp_program_version = "mandosclient 0.9";
80
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
110
81
static const char mandos_protocol_version[] = "1";
111
const char *argp_program_version = "mandos-client " VERSION;
112
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
114
83
/* Used for passing in values through the Avahi callback functions */
119
88
unsigned int dh_bits;
120
89
gnutls_dh_params_t dh_params;
121
90
const char *priority;
126
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
93
/* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
127
94
* "buffer_capacity" is how much is currently allocated,
128
* "buffer_length" is how much is already used.
95
* "buffer_length" is how much is already used. */
130
96
size_t adjustbuffer(char **buffer, size_t buffer_length,
131
97
size_t buffer_capacity){
132
98
if (buffer_length + BUFFER_SIZE > buffer_capacity){
109
* Decrypt OpenPGP data using keyrings in HOMEDIR.
110
* Returns -1 on error
145
static bool init_gpgme(mandos_context *mc, const char *seckey,
146
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;
148
118
gpgme_error_t rc;
120
size_t plaintext_capacity = 0;
121
ssize_t plaintext_length = 0;
149
122
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 = 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 = TEMP_FAILURE_RETRY(close(fd));
183
gpgme_data_release(pgp_data);
188
fprintf(stderr, "Initialize gpgme\n");
125
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
194
131
if (rc != GPG_ERR_NO_ERROR){
195
132
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
196
133
gpgme_strsource(rc), gpgme_strerror(rc));
200
/* Set GPGME home directory for the OpenPGP engine only */
137
/* Set GPGME home directory for the OpenPGP engine only */
201
138
rc = gpgme_get_engine_info (&engine_info);
202
139
if (rc != GPG_ERR_NO_ERROR){
203
140
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
204
141
gpgme_strsource(rc), gpgme_strerror(rc));
207
144
while(engine_info != NULL){
208
145
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
209
146
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
210
engine_info->file_name, tempdir);
147
engine_info->file_name, homedir);
213
150
engine_info = engine_info->next;
215
152
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");
153
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
253
157
/* Create new GPGME data buffer from memory cryptotext */
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;
271
184
/* Decrypt data from the cryptotext data buffer to the plaintext
273
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
186
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
274
187
if (rc != GPG_ERR_NO_ERROR){
275
188
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
276
189
gpgme_strsource(rc), gpgme_strerror(rc));
277
190
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
191
goto decrypt_end;
310
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;
313
227
/* Seek back to the beginning of the GPGME plaintext data buffer */
314
228
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
315
perror("gpgme_data_seek");
229
perror("pgpme_data_seek");
316
230
plaintext_length = -1;
317
231
goto decrypt_end;
377
291
static int init_gnutls_global(mandos_context *mc,
378
const char *pubkeyfilename,
379
const char *seckeyfilename){
292
const char *pubkeyfile,
293
const char *seckeyfile){
383
297
fprintf(stderr, "Initializing GnuTLS\n");
386
ret = gnutls_global_init();
387
if (ret != GNUTLS_E_SUCCESS) {
300
if ((ret = gnutls_global_init ())
301
!= GNUTLS_E_SUCCESS) {
388
302
fprintf (stderr, "GnuTLS global_init: %s\n",
389
303
safer_gnutls_strerror(ret));
401
315
/* OpenPGP credentials */
402
gnutls_certificate_allocate_credentials(&mc->cred);
403
if (ret != GNUTLS_E_SUCCESS){
404
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
316
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
317
!= GNUTLS_E_SUCCESS) {
318
fprintf (stderr, "GnuTLS memory error: %s\n",
406
319
safer_gnutls_strerror(ret));
407
gnutls_global_deinit ();
412
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
413
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
324
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
325
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
417
329
ret = gnutls_certificate_set_openpgp_key_file
418
(mc->cred, pubkeyfilename, seckeyfilename,
419
GNUTLS_OPENPGP_FMT_BASE64);
330
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
420
331
if (ret != GNUTLS_E_SUCCESS) {
422
333
"Error[%d] while reading the OpenPGP key pair ('%s',"
423
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
424
fprintf(stderr, "The GnuTLS error is: %s\n",
334
" '%s')\n", ret, pubkeyfile, seckeyfile);
335
fprintf(stdout, "The GnuTLS error is: %s\n",
425
336
safer_gnutls_strerror(ret));
429
340
/* GnuTLS server initialization */
431
342
if (ret != GNUTLS_E_SUCCESS) {
432
343
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
433
344
" %s\n", safer_gnutls_strerror(ret));
436
347
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
437
348
if (ret != GNUTLS_E_SUCCESS) {
438
349
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
439
350
safer_gnutls_strerror(ret));
443
354
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
449
gnutls_certificate_free_credentials(mc->cred);
450
gnutls_global_deinit();
451
gnutls_dh_params_deinit(mc->dh_params);
455
359
static int init_gnutls_session(mandos_context *mc,
549
451
fprintf(stderr, "Bad address: %s\n", ip);
552
to.in6.sin6_port = htons(port); /* Spurious warning */
454
to.in6.sin6_port = htons(port); /* Spurious warning */
554
456
to.in6.sin6_scope_id = (uint32_t)if_index;
557
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
459
fprintf(stderr, "Connection to: %s, port %d\n", ip, port);
559
460
char addrstr[INET6_ADDRSTRLEN] = "";
560
461
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
561
462
sizeof(addrstr)) == NULL){
744
639
char ip[AVAHI_ADDRESS_STR_MAX];
745
640
avahi_address_snprint(ip, sizeof(ip), address);
747
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
748
PRIu16 ") on port %d\n", name, host_name, ip,
642
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %d) on"
643
" port %d\n", name, host_name, ip, interface, port);
751
645
int ret = start_mandos_communication(ip, port, interface, mc);
753
avahi_simple_poll_quit(mc->simple_poll);
705
/* Combines file name and path and returns the malloced new
706
string. some sane checks could/should be added */
707
static const char *combinepath(const char *first, const char *second){
708
size_t f_len = strlen(first);
709
size_t s_len = strlen(second);
710
char *tmp = malloc(f_len + s_len + 2);
715
memcpy(tmp, first, f_len); /* Spurious warning */
719
memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */
721
tmp[f_len + 1 + s_len] = '\0';
811
726
int main(int argc, char *argv[]){
812
727
AvahiSServiceBrowser *sb = NULL;
821
736
char *connect_to = NULL;
822
char tempdir[] = "/tmp/mandosXXXXXX";
823
737
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
824
const char *seckey = PATHDIR "/" SECKEY;
825
const char *pubkey = PATHDIR "/" PUBKEY;
738
const char *pubkeyfile = "pubkey.txt";
739
const char *seckeyfile = "seckey.txt";
827
740
mandos_context mc = { .simple_poll = NULL, .server = NULL,
828
.dh_bits = 1024, .priority = "SECURE256"
829
":!CTYPE-X.509:+CTYPE-OPENPGP" };
830
bool gnutls_initalized = false;
831
bool gpgme_initalized = false;
741
.dh_bits = 1024, .priority = "SECURE256"};
834
744
struct argp_option options[] = {
835
745
{ .name = "debug", .key = 128,
836
746
.doc = "Debug mode", .group = 3 },
837
747
{ .name = "connect", .key = 'c',
838
.arg = "ADDRESS:PORT",
839
.doc = "Connect directly to a specific Mandos server",
749
.doc = "Connect directly to a sepcified mandos server",
841
751
{ .name = "interface", .key = 'i',
843
.doc = "Interface that will be used to search for Mandos"
753
.doc = "Interface that Avahi will conntect through",
755
{ .name = "keydir", .key = 'd',
757
.doc = "Directory where the openpgp keyring is",
846
759
{ .name = "seckey", .key = 's',
848
.doc = "OpenPGP secret key file base name",
761
.doc = "Secret openpgp key for gnutls authentication",
850
763
{ .name = "pubkey", .key = 'p',
852
.doc = "OpenPGP public key file base name",
765
.doc = "Public openpgp key for gnutls authentication",
854
767
{ .name = "dh-bits", .key = 129,
856
.doc = "Bit length of the prime number used in the"
857
" Diffie-Hellman key exchange",
769
.doc = "dh-bits to use in gnutls communication",
859
771
{ .name = "priority", .key = 130,
861
.doc = "GnuTLS priority string for the TLS handshake",
773
.doc = "GNUTLS priority", .group = 1 },
866
778
error_t parse_opt (int key, char *arg,
867
779
struct argp_state *state) {
868
780
/* Get the INPUT argument from `argp_parse', which we know is
869
781
a pointer to our plugin list pointer. */
871
case 128: /* --debug */
874
case 'c': /* --connect */
875
787
connect_to = arg;
877
case 'i': /* --interface */
880
case 's': /* --seckey */
883
case 'p': /* --pubkey */
886
case 129: /* --dh-bits */
888
803
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
891
806
exit(EXIT_FAILURE);
894
case 130: /* --priority */
895
810
mc.priority = arg;
897
812
case ARGP_KEY_ARG:
898
813
argp_usage (state);
902
818
return ARGP_ERR_UNKNOWN;
907
823
struct argp argp = { .options = options, .parser = parse_opt,
909
825
.doc = "Mandos client -- Get and decrypt"
910
" passwords from a Mandos server" };
911
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
912
if (ret == ARGP_ERR_UNKNOWN){
913
fprintf(stderr, "Unknown error while parsing arguments\n");
914
exitcode = EXIT_FAILURE;
919
/* If the interface is down, bring it up */
921
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
924
exitcode = EXIT_FAILURE;
927
strcpy(network.ifr_name, interface);
928
ret = ioctl(sd, SIOCGIFFLAGS, &network);
930
perror("ioctl SIOCGIFFLAGS");
931
exitcode = EXIT_FAILURE;
934
if((network.ifr_flags & IFF_UP) == 0){
935
network.ifr_flags |= IFF_UP;
936
ret = ioctl(sd, SIOCSIFFLAGS, &network);
938
perror("ioctl SIOCSIFFLAGS");
939
exitcode = EXIT_FAILURE;
943
ret = TEMP_FAILURE_RETRY(close(sd));
826
" passwords from mandos server" };
827
argp_parse (&argp, argc, argv, 0, 0, NULL);
830
pubkeyfile = combinepath(keydir, pubkeyfile);
831
if (pubkeyfile == NULL){
832
perror("combinepath");
833
exitcode = EXIT_FAILURE;
837
seckeyfile = combinepath(keydir, seckeyfile);
838
if (seckeyfile == NULL){
839
perror("combinepath");
843
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
845
fprintf(stderr, "init_gnutls_global\n");
952
852
ret = setuid(uid);
954
854
perror("setuid");
959
859
perror("setgid");
962
ret = init_gnutls_global(&mc, pubkey, seckey);
964
fprintf(stderr, "init_gnutls_global failed\n");
965
exitcode = EXIT_FAILURE;
968
gnutls_initalized = true;
971
if(mkdtemp(tempdir) == NULL){
977
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
978
fprintf(stderr, "gpgme_initalized failed\n");
979
exitcode = EXIT_FAILURE;
982
gpgme_initalized = true;
985
862
if_index = (AvahiIfIndex) if_nametoindex(interface);
986
863
if(if_index == 0){
987
864
fprintf(stderr, "No such interface: \"%s\"\n", interface);
895
/* If the interface is down, bring it up */
897
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
900
exitcode = EXIT_FAILURE;
903
strcpy(network.ifr_name, interface); /* Spurious warning */
904
ret = ioctl(sd, SIOCGIFFLAGS, &network);
906
perror("ioctl SIOCGIFFLAGS");
907
exitcode = EXIT_FAILURE;
910
if((network.ifr_flags & IFF_UP) == 0){
911
network.ifr_flags |= IFF_UP;
912
ret = ioctl(sd, SIOCSIFFLAGS, &network);
914
perror("ioctl SIOCSIFFLAGS");
915
exitcode = EXIT_FAILURE;
1019
923
avahi_set_log_function(empty_log);
1090
994
if (mc.server != NULL)
1091
995
avahi_server_free(mc.server);
1093
997
if (mc.simple_poll != NULL)
1094
998
avahi_simple_poll_free(mc.simple_poll);
1096
if (gnutls_initalized){
1097
gnutls_certificate_free_credentials(mc.cred);
1098
gnutls_global_deinit ();
1099
gnutls_dh_params_deinit(mc.dh_params);
1102
if(gpgme_initalized){
1103
gpgme_release(mc.ctx);
1106
/* Removes the temp directory used by GPGME */
1107
if(tempdir[0] != '\0'){
1109
struct dirent *direntry;
1110
d = opendir(tempdir);
1115
direntry = readdir(d);
1116
if(direntry == NULL){
1119
if (direntry->d_type == DT_REG){
1120
char *fullname = NULL;
1121
ret = asprintf(&fullname, "%s/%s", tempdir,
1127
ret = unlink(fullname);
1129
fprintf(stderr, "unlink(\"%s\"): %s",
1130
fullname, strerror(errno));
1137
ret = rmdir(tempdir);
1143
1002
return exitcode;