32
32
#define _LARGEFILE_SOURCE
33
33
#define _FILE_OFFSET_BITS 64
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(),
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
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(), asprintf(), strcpy() */
45
strerror(), memcpy(), 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,
50
uid_t, gid_t, open(), opendir(), DIR */
51
#include <sys/stat.h> /* open() */
51
#include <inttypes.h> /* PRIu16 */
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 */
58
55
#include <assert.h> /* assert() */
59
56
#include <errno.h> /* perror(), errno */
60
57
#include <time.h> /* time() */
61
58
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
62
59
SIOCSIFFLAGS, if_indextoname(),
63
60
if_nametoindex(), IF_NAMESIZE */
64
#include <netinet/in.h>
65
61
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
66
62
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
68
65
#include <arpa/inet.h> /* inet_pton(), htons */
69
66
#include <iso646.h> /* not, and */
70
67
#include <argp.h> /* struct argp_option, error_t, struct
93
89
GNUTLS_OPENPGP_FMT_BASE64 */
96
#include <gpgme.h> /* All GPGME types, constants and
92
#include <gpgme.h> /* All GPGME types, constants and functions
99
94
GPGME_PROTOCOL_OpenPGP,
102
97
#define BUFFER_SIZE 256
105
#define PATHDIR "/conf/conf.d/mandos"
108
#define PATHDIR "/conf/conf.d/mandos"
109
#define SECKEY "seckey.txt"
110
#define PUBKEY "pubkey.txt"
112
99
bool debug = false;
100
static const char *keydir = "/conf/conf.d/mandos";
113
101
static const char mandos_protocol_version[] = "1";
114
const char *argp_program_version = "mandos-client 1.0";
102
const char *argp_program_version = "password-request 1.0";
115
103
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
117
105
/* Used for passing in values through the Avahi callback functions */
133
* Decrypt OpenPGP data using keyrings in HOMEDIR.
134
* Returns -1 on error
148
static bool init_gpgme(mandos_context *mc, const char *seckey,
149
const char *pubkey, const char *tempdir){
136
static ssize_t pgp_packet_decrypt (const char *cryptotext,
139
const char *homedir){
140
gpgme_data_t dh_crypto, dh_plain;
151
142
gpgme_error_t rc;
144
size_t plaintext_capacity = 0;
145
ssize_t plaintext_length = 0;
152
146
gpgme_engine_info_t engine_info;
156
* Helper function to insert pub and seckey to the enigne keyring.
158
bool import_key(const char *filename){
160
gpgme_data_t pgp_data;
162
fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
168
rc = gpgme_data_new_from_fd(&pgp_data, fd);
169
if (rc != GPG_ERR_NO_ERROR){
170
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
171
gpgme_strsource(rc), gpgme_strerror(rc));
175
rc = gpgme_op_import(mc->ctx, pgp_data);
176
if (rc != GPG_ERR_NO_ERROR){
177
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
178
gpgme_strsource(rc), gpgme_strerror(rc));
182
ret = TEMP_FAILURE_RETRY(close(fd));
186
gpgme_data_release(pgp_data);
191
fprintf(stderr, "Initialize gpgme\n");
149
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
197
155
if (rc != GPG_ERR_NO_ERROR){
198
156
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
199
157
gpgme_strsource(rc), gpgme_strerror(rc));
203
/* Set GPGME home directory for the OpenPGP engine only */
161
/* Set GPGME home directory for the OpenPGP engine only */
204
162
rc = gpgme_get_engine_info (&engine_info);
205
163
if (rc != GPG_ERR_NO_ERROR){
206
164
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
207
165
gpgme_strsource(rc), gpgme_strerror(rc));
210
168
while(engine_info != NULL){
211
169
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
212
170
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
213
engine_info->file_name, tempdir);
171
engine_info->file_name, homedir);
216
174
engine_info = engine_info->next;
218
176
if(engine_info == NULL){
219
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
223
/* Create new GPGME "context" */
224
rc = gpgme_new(&(mc->ctx));
225
if (rc != GPG_ERR_NO_ERROR){
226
fprintf(stderr, "bad gpgme_new: %s: %s\n",
227
gpgme_strsource(rc), gpgme_strerror(rc));
231
if (not import_key(pubkey) or not import_key(seckey)){
239
* Decrypt OpenPGP data.
240
* Returns -1 on error
242
static ssize_t pgp_packet_decrypt (const mandos_context *mc,
243
const char *cryptotext,
246
gpgme_data_t dh_crypto, dh_plain;
249
size_t plaintext_capacity = 0;
250
ssize_t plaintext_length = 0;
253
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
177
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
256
181
/* 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;
274
208
/* Decrypt data from the cryptotext data buffer to the plaintext
276
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
210
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
277
211
if (rc != GPG_ERR_NO_ERROR){
278
212
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
279
213
gpgme_strsource(rc), gpgme_strerror(rc));
280
214
plaintext_length = -1;
282
gpgme_decrypt_result_t result;
283
result = gpgme_op_decrypt_result(mc->ctx);
285
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
287
fprintf(stderr, "Unsupported algorithm: %s\n",
288
result->unsupported_algorithm);
289
fprintf(stderr, "Wrong key usage: %u\n",
290
result->wrong_key_usage);
291
if(result->file_name != NULL){
292
fprintf(stderr, "File name: %s\n", result->file_name);
294
gpgme_recipient_t recipient;
295
recipient = result->recipients;
297
while(recipient != NULL){
298
fprintf(stderr, "Public key algorithm: %s\n",
299
gpgme_pubkey_algo_name(recipient->pubkey_algo));
300
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
301
fprintf(stderr, "Secret key available: %s\n",
302
recipient->status == GPG_ERR_NO_SECKEY
304
recipient = recipient->next;
309
215
goto decrypt_end;
313
219
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;
316
251
/* Seek back to the beginning of the GPGME plaintext data buffer */
317
252
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
318
253
perror("pgpme_data_seek");
404
339
/* OpenPGP credentials */
405
340
gnutls_certificate_allocate_credentials(&mc->cred);
406
341
if (ret != GNUTLS_E_SUCCESS){
407
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
342
fprintf (stderr, "GnuTLS memory error: %s\n",
409
343
safer_gnutls_strerror(ret));
410
344
gnutls_global_deinit ();
415
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
416
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
349
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
350
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
420
354
ret = gnutls_certificate_set_openpgp_key_file
421
(mc->cred, pubkeyfilename, seckeyfilename,
422
GNUTLS_OPENPGP_FMT_BASE64);
355
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
423
356
if (ret != GNUTLS_E_SUCCESS) {
425
358
"Error[%d] while reading the OpenPGP key pair ('%s',"
426
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
427
fprintf(stderr, "The GnuTLS error is: %s\n",
359
" '%s')\n", ret, pubkeyfile, seckeyfile);
360
fprintf(stdout, "The GnuTLS error is: %s\n",
428
361
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';
813
764
int main(int argc, char *argv[]){
814
765
AvahiSServiceBrowser *sb = NULL;
823
774
char *connect_to = NULL;
824
char tempdir[] = "/tmp/mandosXXXXXX";
825
775
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
826
const char *seckey = PATHDIR "/" SECKEY;
827
const char *pubkey = PATHDIR "/" PUBKEY;
776
const char *pubkeyfile = "pubkey.txt";
777
const char *seckeyfile = "seckey.txt";
829
778
mandos_context mc = { .simple_poll = NULL, .server = NULL,
830
.dh_bits = 1024, .priority = "SECURE256"
831
":!CTYPE-X.509:+CTYPE-OPENPGP" };
779
.dh_bits = 1024, .priority = "SECURE256"};
832
780
bool gnutls_initalized = false;
833
bool pgpme_initalized = false;
836
783
struct argp_option options[] = {
837
784
{ .name = "debug", .key = 128,
838
785
.doc = "Debug mode", .group = 3 },
839
786
{ .name = "connect", .key = 'c',
840
.arg = "ADDRESS:PORT",
841
.doc = "Connect directly to a specific Mandos server",
788
.doc = "Connect directly to a sepcified mandos server",
843
790
{ .name = "interface", .key = 'i',
845
.doc = "Interface that will be used to search for Mandos"
792
.doc = "Interface that Avahi will conntect through",
794
{ .name = "keydir", .key = 'd',
796
.doc = "Directory where the openpgp keyring is",
848
798
{ .name = "seckey", .key = 's',
850
.doc = "OpenPGP secret key file base name",
800
.doc = "Secret openpgp key for gnutls authentication",
852
802
{ .name = "pubkey", .key = 'p',
854
.doc = "OpenPGP public key file base name",
804
.doc = "Public openpgp key for gnutls authentication",
856
806
{ .name = "dh-bits", .key = 129,
858
.doc = "Bit length of the prime number used in the"
859
" Diffie-Hellman key exchange",
808
.doc = "dh-bits to use in gnutls communication",
861
810
{ .name = "priority", .key = 130,
863
.doc = "GnuTLS priority string for the TLS handshake",
812
.doc = "GNUTLS priority", .group = 1 },
868
817
error_t parse_opt (int key, char *arg,
869
818
struct argp_state *state) {
870
819
/* Get the INPUT argument from `argp_parse', which we know is
871
820
a pointer to our plugin list pointer. */
873
case 128: /* --debug */
876
case 'c': /* --connect */
877
826
connect_to = arg;
879
case 'i': /* --interface */
882
case 's': /* --seckey */
885
case 'p': /* --pubkey */
888
case 129: /* --dh-bits */
890
842
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
893
845
exit(EXIT_FAILURE);
896
case 130: /* --priority */
897
849
mc.priority = arg;
899
851
case ARGP_KEY_ARG:
900
852
argp_usage (state);
904
857
return ARGP_ERR_UNKNOWN;
909
862
struct argp argp = { .options = options, .parser = parse_opt,
911
864
.doc = "Mandos client -- Get and decrypt"
912
" passwords from a Mandos server" };
865
" passwords from mandos server" };
913
866
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
914
867
if (ret == ARGP_ERR_UNKNOWN){
915
868
fprintf(stderr, "Unknown error while parsing arguments\n");
961
932
perror("setgid");
964
ret = init_gnutls_global(&mc, pubkey, seckey);
966
fprintf(stderr, "init_gnutls_global failed\n");
967
exitcode = EXIT_FAILURE;
970
gnutls_initalized = true;
973
if(mkdtemp(tempdir) == NULL){
979
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
980
fprintf(stderr, "pgpme_initalized failed\n");
981
exitcode = EXIT_FAILURE;
984
pgpme_initalized = true;
987
935
if_index = (AvahiIfIndex) if_nametoindex(interface);
988
936
if(if_index == 0){
989
937
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1041
989
config.publish_addresses = 0;
1042
990
config.publish_workstation = 0;
1043
991
config.publish_domain = 0;
1045
993
/* Allocate a new server */
1046
994
mc.server = avahi_server_new(avahi_simple_poll_get
1047
995
(mc.simple_poll), &config, NULL,
1050
998
/* Free the Avahi configuration data */
1051
999
avahi_server_config_free(&config);
1092
1040
if (mc.server != NULL)
1093
1041
avahi_server_free(mc.server);
1095
1043
if (mc.simple_poll != NULL)
1096
1044
avahi_simple_poll_free(mc.simple_poll);
1098
1048
if (gnutls_initalized){
1099
1049
gnutls_certificate_free_credentials(mc.cred);
1100
1050
gnutls_global_deinit ();
1103
if(pgpme_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));
1137
ret = rmdir(tempdir);
1143
1053
return exitcode;