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() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
37
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
#include <stdint.h> /* uint16_t, uint32_t */
40
#include <stddef.h> /* NULL, size_t, ssize_t */
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
#include <stdbool.h> /* bool, true */
44
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), asprintf(), strcpy() */
46
#include <sys/ioctl.h> /* ioctl */
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
sockaddr_in6, PF_INET6,
49
SOCK_STREAM, INET6_ADDRSTRLEN,
50
uid_t, gid_t, open(), opendir(), DIR */
51
#include <sys/stat.h> /* open() */
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
struct in6_addr, inet_pton(),
55
#include <fcntl.h> /* open() */
56
#include <dirent.h> /* opendir(), struct dirent, readdir() */
57
#include <inttypes.h> /* PRIu16 */
58
#include <assert.h> /* assert() */
59
#include <errno.h> /* perror(), errno */
60
#include <time.h> /* time() */
44
61
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
62
SIOCSIFFLAGS, if_indextoname(),
63
if_nametoindex(), IF_NAMESIZE */
64
#include <netinet/in.h>
65
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
66
getuid(), getgid(), setuid(),
68
#include <arpa/inet.h> /* inet_pton(), htons */
69
#include <iso646.h> /* not, and */
70
#include <argp.h> /* struct argp_option, error_t, struct
71
argp_state, struct argp,
72
argp_parse(), ARGP_KEY_ARG,
73
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
76
/* All Avahi types, constants and functions
47
79
#include <avahi-core/core.h>
48
80
#include <avahi-core/lookup.h>
49
81
#include <avahi-core/log.h>
51
83
#include <avahi-common/malloc.h>
52
84
#include <avahi-common/error.h>
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 */
87
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
90
init_gnutls_session(),
92
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
93
GNUTLS_OPENPGP_FMT_BASE64 */
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,
72
#include <errno.h> /* perror() */
96
#include <gpgme.h> /* All GPGME types, constants and
99
GPGME_PROTOCOL_OpenPGP,
75
102
#define BUFFER_SIZE 256
104
#define PATHDIR "/conf/conf.d/mandos"
105
#define SECKEY "seckey.txt"
106
#define PUBKEY "pubkey.txt"
77
108
bool debug = false;
78
static const char *keydir = "/conf/conf.d/mandos";
79
const char *argp_program_version = "mandosclient 0.9";
109
static const char mandos_protocol_version[] = "1";
110
const char *argp_program_version = "mandos-client " VERSION;
80
111
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
81
static const char mandos_protocol_version[] = "1";
83
113
/* Used for passing in values through the Avahi callback functions */
88
118
unsigned int dh_bits;
89
119
gnutls_dh_params_t dh_params;
90
120
const char *priority;
93
/* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
125
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
94
126
* "buffer_capacity" is how much is currently allocated,
95
* "buffer_length" is how much is already used. */
127
* "buffer_length" is how much is already used.
96
129
size_t adjustbuffer(char **buffer, size_t buffer_length,
97
130
size_t buffer_capacity){
98
131
if (buffer_length + BUFFER_SIZE > buffer_capacity){
109
* Decrypt OpenPGP data using keyrings in HOMEDIR.
110
* Returns -1 on error
112
static ssize_t pgp_packet_decrypt (const char *cryptotext,
115
const char *homedir){
116
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){
118
147
gpgme_error_t rc;
120
size_t plaintext_capacity = 0;
121
ssize_t plaintext_length = 0;
122
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);
125
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
187
fprintf(stderr, "Initialize gpgme\n");
131
193
if (rc != GPG_ERR_NO_ERROR){
132
194
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
133
195
gpgme_strsource(rc), gpgme_strerror(rc));
137
/* Set GPGME home directory for the OpenPGP engine only */
199
/* Set GPGME home directory for the OpenPGP engine only */
138
200
rc = gpgme_get_engine_info (&engine_info);
139
201
if (rc != GPG_ERR_NO_ERROR){
140
202
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
141
203
gpgme_strsource(rc), gpgme_strerror(rc));
144
206
while(engine_info != NULL){
145
207
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
146
208
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
147
engine_info->file_name, homedir);
209
engine_info->file_name, tempdir);
150
212
engine_info = engine_info->next;
152
214
if(engine_info == NULL){
153
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");
157
252
/* 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;
184
270
/* Decrypt data from the cryptotext data buffer to the plaintext
186
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
272
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
187
273
if (rc != GPG_ERR_NO_ERROR){
188
274
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
189
275
gpgme_strsource(rc), gpgme_strerror(rc));
190
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;
191
305
goto decrypt_end;
195
309
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;
227
312
/* Seek back to the beginning of the GPGME plaintext data buffer */
228
313
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
229
perror("pgpme_data_seek");
314
perror("gpgme_data_seek");
230
315
plaintext_length = -1;
231
316
goto decrypt_end;
291
376
static int init_gnutls_global(mandos_context *mc,
292
const char *pubkeyfile,
293
const char *seckeyfile){
377
const char *pubkeyfilename,
378
const char *seckeyfilename){
297
382
fprintf(stderr, "Initializing GnuTLS\n");
300
if ((ret = gnutls_global_init ())
301
!= GNUTLS_E_SUCCESS) {
385
ret = gnutls_global_init();
386
if (ret != GNUTLS_E_SUCCESS) {
302
387
fprintf (stderr, "GnuTLS global_init: %s\n",
303
388
safer_gnutls_strerror(ret));
315
400
/* OpenPGP credentials */
316
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
317
!= GNUTLS_E_SUCCESS) {
318
fprintf (stderr, "GnuTLS memory error: %s\n",
401
gnutls_certificate_allocate_credentials(&mc->cred);
402
if (ret != GNUTLS_E_SUCCESS){
403
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
319
405
safer_gnutls_strerror(ret));
406
gnutls_global_deinit ();
324
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
325
" 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,
329
416
ret = gnutls_certificate_set_openpgp_key_file
330
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
417
(mc->cred, pubkeyfilename, seckeyfilename,
418
GNUTLS_OPENPGP_FMT_BASE64);
331
419
if (ret != GNUTLS_E_SUCCESS) {
333
421
"Error[%d] while reading the OpenPGP key pair ('%s',"
334
" '%s')\n", ret, pubkeyfile, seckeyfile);
335
fprintf(stdout, "The GnuTLS error is: %s\n",
422
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
423
fprintf(stderr, "The GnuTLS error is: %s\n",
336
424
safer_gnutls_strerror(ret));
340
428
/* GnuTLS server initialization */
342
430
if (ret != GNUTLS_E_SUCCESS) {
343
431
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
344
432
" %s\n", safer_gnutls_strerror(ret));
347
435
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
348
436
if (ret != GNUTLS_E_SUCCESS) {
349
437
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
350
438
safer_gnutls_strerror(ret));
354
442
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
448
gnutls_certificate_free_credentials(mc->cred);
449
gnutls_global_deinit();
450
gnutls_dh_params_deinit(mc->dh_params);
359
454
static int init_gnutls_session(mandos_context *mc,
451
548
fprintf(stderr, "Bad address: %s\n", ip);
454
to.in6.sin6_port = htons(port); /* Spurious warning */
551
to.in6.sin6_port = htons(port); /* Spurious warning */
456
553
to.in6.sin6_scope_id = (uint32_t)if_index;
459
fprintf(stderr, "Connection to: %s, port %d\n", ip, port);
556
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
460
558
char addrstr[INET6_ADDRSTRLEN] = "";
461
559
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
462
560
sizeof(addrstr)) == NULL){
639
743
char ip[AVAHI_ADDRESS_STR_MAX];
640
744
avahi_address_snprint(ip, sizeof(ip), address);
642
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %d) on"
643
" port %d\n", name, host_name, ip, interface, port);
746
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
747
PRIu16 ") on port %d\n", name, host_name, ip,
645
750
int ret = start_mandos_communication(ip, port, interface, mc);
752
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';
726
810
int main(int argc, char *argv[]){
727
811
AvahiSServiceBrowser *sb = NULL;
736
820
char *connect_to = NULL;
821
char tempdir[] = "/tmp/mandosXXXXXX";
737
822
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
738
const char *pubkeyfile = "pubkey.txt";
739
const char *seckeyfile = "seckey.txt";
823
const char *seckey = PATHDIR "/" SECKEY;
824
const char *pubkey = PATHDIR "/" PUBKEY;
740
826
mandos_context mc = { .simple_poll = NULL, .server = NULL,
741
.dh_bits = 1024, .priority = "SECURE256"};
827
.dh_bits = 1024, .priority = "SECURE256"
828
":!CTYPE-X.509:+CTYPE-OPENPGP" };
829
bool gnutls_initalized = false;
830
bool gpgme_initalized = false;
744
833
struct argp_option options[] = {
745
834
{ .name = "debug", .key = 128,
746
835
.doc = "Debug mode", .group = 3 },
747
836
{ .name = "connect", .key = 'c',
749
.doc = "Connect directly to a sepcified mandos server",
837
.arg = "ADDRESS:PORT",
838
.doc = "Connect directly to a specific Mandos server",
751
840
{ .name = "interface", .key = 'i',
753
.doc = "Interface that Avahi will conntect through",
755
{ .name = "keydir", .key = 'd',
757
.doc = "Directory where the openpgp keyring is",
842
.doc = "Interface that will be used to search for Mandos"
759
845
{ .name = "seckey", .key = 's',
761
.doc = "Secret openpgp key for gnutls authentication",
847
.doc = "OpenPGP secret key file base name",
763
849
{ .name = "pubkey", .key = 'p',
765
.doc = "Public openpgp key for gnutls authentication",
851
.doc = "OpenPGP public key file base name",
767
853
{ .name = "dh-bits", .key = 129,
769
.doc = "dh-bits to use in gnutls communication",
855
.doc = "Bit length of the prime number used in the"
856
" Diffie-Hellman key exchange",
771
858
{ .name = "priority", .key = 130,
773
.doc = "GNUTLS priority", .group = 1 },
860
.doc = "GnuTLS priority string for the TLS handshake",
778
865
error_t parse_opt (int key, char *arg,
779
866
struct argp_state *state) {
780
867
/* Get the INPUT argument from `argp_parse', which we know is
781
868
a pointer to our plugin list pointer. */
870
case 128: /* --debug */
873
case 'c': /* --connect */
787
874
connect_to = arg;
876
case 'i': /* --interface */
879
case 's': /* --seckey */
882
case 'p': /* --pubkey */
885
case 129: /* --dh-bits */
803
887
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
806
890
exit(EXIT_FAILURE);
893
case 130: /* --priority */
810
894
mc.priority = arg;
812
896
case ARGP_KEY_ARG:
813
897
argp_usage (state);
818
901
return ARGP_ERR_UNKNOWN;
823
906
struct argp argp = { .options = options, .parser = parse_opt,
825
908
.doc = "Mandos client -- Get and decrypt"
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");
909
" passwords from a Mandos server" };
910
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
911
if (ret == ARGP_ERR_UNKNOWN){
912
fprintf(stderr, "Unknown error while parsing arguments\n");
913
exitcode = EXIT_FAILURE;
918
/* If the interface is down, bring it up */
920
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
923
exitcode = EXIT_FAILURE;
926
strcpy(network.ifr_name, interface);
927
ret = ioctl(sd, SIOCGIFFLAGS, &network);
929
perror("ioctl SIOCGIFFLAGS");
930
exitcode = EXIT_FAILURE;
933
if((network.ifr_flags & IFF_UP) == 0){
934
network.ifr_flags |= IFF_UP;
935
ret = ioctl(sd, SIOCSIFFLAGS, &network);
937
perror("ioctl SIOCSIFFLAGS");
938
exitcode = EXIT_FAILURE;
942
ret = TEMP_FAILURE_RETRY(close(sd));
852
951
ret = setuid(uid);
854
953
perror("setuid");
859
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;
862
984
if_index = (AvahiIfIndex) if_nametoindex(interface);
863
985
if(if_index == 0){
864
986
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;
923
1018
avahi_set_log_function(empty_log);
994
1089
if (mc.server != NULL)
995
1090
avahi_server_free(mc.server);
997
1092
if (mc.simple_poll != NULL)
998
1093
avahi_simple_poll_free(mc.simple_poll);
1095
if (gnutls_initalized){
1096
gnutls_certificate_free_credentials(mc.cred);
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);
1002
1142
return exitcode;