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(),
39
stdout, ferror(), sscanf */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
40
39
#include <stdint.h> /* uint16_t, uint32_t */
41
40
#include <stddef.h> /* NULL, size_t, ssize_t */
42
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
44
43
#include <stdbool.h> /* bool, true */
45
44
#include <string.h> /* memset(), strcmp(), strlen(),
46
strerror(), asprintf(), strcpy() */
45
strerror(), memcpy(), strcpy() */
47
46
#include <sys/ioctl.h> /* ioctl */
48
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
49
48
sockaddr_in6, PF_INET6,
50
49
SOCK_STREAM, INET6_ADDRSTRLEN,
51
uid_t, gid_t, open(), opendir(), DIR */
52
#include <sys/stat.h> /* open() */
51
#include <inttypes.h> /* PRIu16 */
53
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
54
53
struct in6_addr, inet_pton(),
56
#include <fcntl.h> /* open() */
57
#include <dirent.h> /* opendir(), struct dirent, readdir() */
58
#include <inttypes.h> /* PRIu16, SCNu16 */
59
55
#include <assert.h> /* assert() */
60
56
#include <errno.h> /* perror(), errno */
61
57
#include <time.h> /* time() */
62
58
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
63
59
SIOCSIFFLAGS, if_indextoname(),
64
60
if_nametoindex(), IF_NAMESIZE */
65
#include <netinet/in.h>
66
61
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
67
62
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
69
65
#include <arpa/inet.h> /* inet_pton(), htons */
70
#include <iso646.h> /* not, and, or */
66
#include <iso646.h> /* not, and */
71
67
#include <argp.h> /* struct argp_option, error_t, struct
72
68
argp_state, struct argp,
73
69
argp_parse(), ARGP_KEY_ARG,
94
89
GNUTLS_OPENPGP_FMT_BASE64 */
97
#include <gpgme.h> /* All GPGME types, constants and
92
#include <gpgme.h> /* All GPGME types, constants and functions
100
94
GPGME_PROTOCOL_OpenPGP,
103
97
#define BUFFER_SIZE 256
105
#define PATHDIR "/conf/conf.d/mandos"
106
#define SECKEY "seckey.txt"
107
#define PUBKEY "pubkey.txt"
109
99
bool debug = false;
100
static const char *keydir = "/conf/conf.d/mandos";
110
101
static const char mandos_protocol_version[] = "1";
111
const char *argp_program_version = "mandos-client " VERSION;
102
const char *argp_program_version = "password-request 1.0";
112
103
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
114
105
/* Used for passing in values through the Avahi callback functions */
133
* Decrypt OpenPGP data using keyrings in HOMEDIR.
134
* Returns -1 on error
145
static bool init_gpgme(mandos_context *mc, const char *seckey,
146
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;
148
142
gpgme_error_t rc;
144
size_t plaintext_capacity = 0;
145
ssize_t plaintext_length = 0;
149
146
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 = (int)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 = (int)TEMP_FAILURE_RETRY(close(fd));
183
gpgme_data_release(pgp_data);
188
fprintf(stderr, "Initialize gpgme\n");
149
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
194
155
if (rc != GPG_ERR_NO_ERROR){
195
156
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
196
157
gpgme_strsource(rc), gpgme_strerror(rc));
200
/* Set GPGME home directory for the OpenPGP engine only */
161
/* Set GPGME home directory for the OpenPGP engine only */
201
162
rc = gpgme_get_engine_info (&engine_info);
202
163
if (rc != GPG_ERR_NO_ERROR){
203
164
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
204
165
gpgme_strsource(rc), gpgme_strerror(rc));
207
168
while(engine_info != NULL){
208
169
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
209
170
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
210
engine_info->file_name, tempdir);
171
engine_info->file_name, homedir);
213
174
engine_info = engine_info->next;
215
176
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");
177
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
253
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;
271
208
/* Decrypt data from the cryptotext data buffer to the plaintext
273
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
210
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
274
211
if (rc != GPG_ERR_NO_ERROR){
275
212
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
276
213
gpgme_strsource(rc), gpgme_strerror(rc));
277
214
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
215
goto decrypt_end;
310
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;
313
251
/* Seek back to the beginning of the GPGME plaintext data buffer */
314
252
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
315
perror("gpgme_data_seek");
253
perror("pgpme_data_seek");
316
254
plaintext_length = -1;
317
255
goto decrypt_end;
401
339
/* OpenPGP credentials */
402
340
gnutls_certificate_allocate_credentials(&mc->cred);
403
341
if (ret != GNUTLS_E_SUCCESS){
404
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
342
fprintf (stderr, "GnuTLS memory error: %s\n",
406
343
safer_gnutls_strerror(ret));
407
344
gnutls_global_deinit ();
412
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
413
" 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,
417
354
ret = gnutls_certificate_set_openpgp_key_file
418
(mc->cred, pubkeyfilename, seckeyfilename,
419
GNUTLS_OPENPGP_FMT_BASE64);
355
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
420
356
if (ret != GNUTLS_E_SUCCESS) {
422
358
"Error[%d] while reading the OpenPGP key pair ('%s',"
423
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
424
fprintf(stderr, "The GnuTLS error is: %s\n",
359
" '%s')\n", ret, pubkeyfile, seckeyfile);
360
fprintf(stdout, "The GnuTLS error is: %s\n",
425
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';
812
764
int main(int argc, char *argv[]){
813
765
AvahiSServiceBrowser *sb = NULL;
822
774
char *connect_to = NULL;
823
char tempdir[] = "/tmp/mandosXXXXXX";
824
775
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
825
const char *seckey = PATHDIR "/" SECKEY;
826
const char *pubkey = PATHDIR "/" PUBKEY;
776
const char *pubkeyfile = "pubkey.txt";
777
const char *seckeyfile = "seckey.txt";
828
778
mandos_context mc = { .simple_poll = NULL, .server = NULL,
829
.dh_bits = 1024, .priority = "SECURE256"
830
":!CTYPE-X.509:+CTYPE-OPENPGP" };
779
.dh_bits = 1024, .priority = "SECURE256"};
831
780
bool gnutls_initalized = false;
832
bool gpgme_initalized = false;
835
783
struct argp_option options[] = {
836
784
{ .name = "debug", .key = 128,
837
785
.doc = "Debug mode", .group = 3 },
838
786
{ .name = "connect", .key = 'c',
839
.arg = "ADDRESS:PORT",
840
.doc = "Connect directly to a specific Mandos server",
788
.doc = "Connect directly to a sepcified mandos server",
842
790
{ .name = "interface", .key = 'i',
844
.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",
847
798
{ .name = "seckey", .key = 's',
849
.doc = "OpenPGP secret key file base name",
800
.doc = "Secret openpgp key for gnutls authentication",
851
802
{ .name = "pubkey", .key = 'p',
853
.doc = "OpenPGP public key file base name",
804
.doc = "Public openpgp key for gnutls authentication",
855
806
{ .name = "dh-bits", .key = 129,
857
.doc = "Bit length of the prime number used in the"
858
" Diffie-Hellman key exchange",
808
.doc = "dh-bits to use in gnutls communication",
860
810
{ .name = "priority", .key = 130,
862
.doc = "GnuTLS priority string for the TLS handshake",
812
.doc = "GNUTLS priority", .group = 1 },
867
817
error_t parse_opt (int key, char *arg,
868
818
struct argp_state *state) {
819
/* Get the INPUT argument from `argp_parse', which we know is
820
a pointer to our plugin list pointer. */
870
case 128: /* --debug */
873
case 'c': /* --connect */
874
826
connect_to = arg;
876
case 'i': /* --interface */
879
case 's': /* --seckey */
882
case 'p': /* --pubkey */
885
case 129: /* --dh-bits */
886
ret = sscanf(arg, "%u", &mc.dh_bits);
888
fprintf(stderr, "Bad number of DH bits\n");
842
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
889
845
exit(EXIT_FAILURE);
892
case 130: /* --priority */
893
849
mc.priority = arg;
895
851
case ARGP_KEY_ARG:
896
852
argp_usage (state);
900
857
return ARGP_ERR_UNKNOWN;
905
862
struct argp argp = { .options = options, .parser = parse_opt,
907
864
.doc = "Mandos client -- Get and decrypt"
908
" passwords from a Mandos server" };
865
" passwords from mandos server" };
909
866
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
910
867
if (ret == ARGP_ERR_UNKNOWN){
911
868
fprintf(stderr, "Unknown error while parsing arguments\n");
957
934
perror("setgid");
960
ret = init_gnutls_global(&mc, pubkey, seckey);
962
fprintf(stderr, "init_gnutls_global failed\n");
963
exitcode = EXIT_FAILURE;
966
gnutls_initalized = true;
969
if(mkdtemp(tempdir) == NULL){
975
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
976
fprintf(stderr, "gpgme_initalized failed\n");
977
exitcode = EXIT_FAILURE;
980
gpgme_initalized = true;
983
937
if_index = (AvahiIfIndex) if_nametoindex(interface);
984
938
if(if_index == 0){
985
939
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1088
1042
if (mc.server != NULL)
1089
1043
avahi_server_free(mc.server);
1091
1045
if (mc.simple_poll != NULL)
1092
1046
avahi_simple_poll_free(mc.simple_poll);
1094
1050
if (gnutls_initalized){
1095
1051
gnutls_certificate_free_credentials(mc.cred);
1096
1052
gnutls_global_deinit ();
1097
gnutls_dh_params_deinit(mc.dh_params);
1100
if(gpgme_initalized){
1101
gpgme_release(mc.ctx);
1104
/* Removes the temp directory used by GPGME */
1105
if(tempdir[0] != '\0'){
1107
struct dirent *direntry;
1108
d = opendir(tempdir);
1110
if(errno != ENOENT){
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);
1138
if(ret == -1 and errno != ENOENT){
1143
1055
return exitcode;