33
32
#define _LARGEFILE_SOURCE
34
33
#define _FILE_OFFSET_BITS 64
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf */
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, SCNu16 */
59
#include <assert.h> /* assert() */
60
#include <errno.h> /* perror(), errno */
61
#include <time.h> /* time() */
39
#include <net/if.h> /* if_nametoindex */
40
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
62
42
#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, or */
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
45
#include <avahi-core/core.h>
81
46
#include <avahi-core/lookup.h>
82
47
#include <avahi-core/log.h>
84
49
#include <avahi-common/malloc.h>
85
50
#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 */
52
/* Mandos client part */
53
#include <sys/types.h> /* socket(), inet_pton() */
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
struct in6_addr, inet_pton() */
56
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
57
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
59
#include <unistd.h> /* close() */
60
#include <netinet/in.h>
61
#include <stdbool.h> /* true */
62
#include <string.h> /* memset */
63
#include <arpa/inet.h> /* inet_pton() */
64
#include <iso646.h> /* not */
65
#include <net/if.h> /* IF_NAMESIZE */
97
#include <gpgme.h> /* All GPGME types, constants and
100
GPGME_PROTOCOL_OpenPGP,
68
#include <errno.h> /* perror() */
103
74
#define BUFFER_SIZE 256
105
#define PATHDIR "/conf/conf.d/mandos"
106
#define SECKEY "seckey.txt"
107
#define PUBKEY "pubkey.txt"
76
static const char *keydir = "/conf/conf.d/mandos";
77
static const char *pubkeyfile = "pubkey.txt";
78
static const char *seckeyfile = "seckey.txt";
109
80
bool debug = false;
110
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
/* Used for passing in values through the Avahi callback functions */
82
/* Used for passing in values through all the callback functions */
116
84
AvahiSimplePoll *simple_poll;
117
85
AvahiServer *server;
118
86
gnutls_certificate_credentials_t cred;
119
87
unsigned int dh_bits;
120
gnutls_dh_params_t dh_params;
121
88
const char *priority;
92
* Decrypt OpenPGP data using keyrings in HOMEDIR.
95
static ssize_t pgp_packet_decrypt (const char *cryptotext,
99
gpgme_data_t dh_crypto, dh_plain;
126
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
127
* "buffer_capacity" is how much is currently allocated,
128
* "buffer_length" is how much is already used.
130
size_t adjustbuffer(char **buffer, size_t buffer_length,
131
size_t buffer_capacity){
132
if (buffer_length + BUFFER_SIZE > buffer_capacity){
133
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
137
buffer_capacity += BUFFER_SIZE;
139
return buffer_capacity;
145
static bool init_gpgme(mandos_context *mc, const char *seckey,
146
const char *pubkey, const char *tempdir){
148
101
gpgme_error_t rc;
103
size_t plaintext_capacity = 0;
104
ssize_t plaintext_length = 0;
149
105
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");
108
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
194
114
if (rc != GPG_ERR_NO_ERROR){
195
115
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
196
116
gpgme_strsource(rc), gpgme_strerror(rc));
200
/* Set GPGME home directory for the OpenPGP engine only */
120
/* Set GPGME home directory for the OpenPGP engine only */
201
121
rc = gpgme_get_engine_info (&engine_info);
202
122
if (rc != GPG_ERR_NO_ERROR){
203
123
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
204
124
gpgme_strsource(rc), gpgme_strerror(rc));
207
127
while(engine_info != NULL){
208
128
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
209
129
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
210
engine_info->file_name, tempdir);
130
engine_info->file_name, homedir);
213
133
engine_info = engine_info->next;
215
135
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");
136
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
253
140
/* Create new GPGME data buffer from memory cryptotext */
158
/* Create new GPGME "context" */
159
rc = gpgme_new(&ctx);
160
if (rc != GPG_ERR_NO_ERROR){
161
fprintf(stderr, "bad gpgme_new: %s: %s\n",
162
gpgme_strsource(rc), gpgme_strerror(rc));
163
plaintext_length = -1;
271
167
/* Decrypt data from the cryptotext data buffer to the plaintext
273
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
169
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
274
170
if (rc != GPG_ERR_NO_ERROR){
275
171
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
276
172
gpgme_strsource(rc), gpgme_strerror(rc));
277
173
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
174
goto decrypt_end;
310
178
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
182
gpgme_decrypt_result_t result;
183
result = gpgme_op_decrypt_result(ctx);
185
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
187
fprintf(stderr, "Unsupported algorithm: %s\n",
188
result->unsupported_algorithm);
189
fprintf(stderr, "Wrong key usage: %d\n",
190
result->wrong_key_usage);
191
if(result->file_name != NULL){
192
fprintf(stderr, "File name: %s\n", result->file_name);
194
gpgme_recipient_t recipient;
195
recipient = result->recipients;
197
while(recipient != NULL){
198
fprintf(stderr, "Public key algorithm: %s\n",
199
gpgme_pubkey_algo_name(recipient->pubkey_algo));
200
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
201
fprintf(stderr, "Secret key available: %s\n",
202
recipient->status == GPG_ERR_NO_SECKEY
204
recipient = recipient->next;
313
210
/* Seek back to the beginning of the GPGME plaintext data buffer */
314
211
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
315
perror("gpgme_data_seek");
212
perror("pgpme_data_seek");
316
213
plaintext_length = -1;
317
214
goto decrypt_end;
320
217
*plaintext = NULL;
322
plaintext_capacity = adjustbuffer(plaintext,
323
(size_t)plaintext_length,
325
if (plaintext_capacity == 0){
326
perror("adjustbuffer");
219
if (plaintext_length + BUFFER_SIZE
220
> (ssize_t) plaintext_capacity){
221
*plaintext = realloc(*plaintext, plaintext_capacity
223
if (*plaintext == NULL){
327
225
plaintext_length = -1;
328
226
goto decrypt_end;
228
plaintext_capacity += BUFFER_SIZE;
331
231
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
401
300
/* OpenPGP credentials */
402
gnutls_certificate_allocate_credentials(&mc->cred);
403
if (ret != GNUTLS_E_SUCCESS){
404
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
301
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
302
!= GNUTLS_E_SUCCESS) {
303
fprintf (stderr, "GnuTLS memory error: %s\n",
406
304
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,
309
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
310
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
417
314
ret = gnutls_certificate_set_openpgp_key_file
418
(mc->cred, pubkeyfilename, seckeyfilename,
419
GNUTLS_OPENPGP_FMT_BASE64);
315
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
420
316
if (ret != GNUTLS_E_SUCCESS) {
422
318
"Error[%d] while reading the OpenPGP key pair ('%s',"
423
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
424
fprintf(stderr, "The GnuTLS error is: %s\n",
319
" '%s')\n", ret, pubkeyfile, seckeyfile);
320
fprintf(stdout, "The GnuTLS error is: %s\n",
425
321
safer_gnutls_strerror(ret));
429
325
/* GnuTLS server initialization */
430
ret = gnutls_dh_params_init(&mc->dh_params);
326
ret = gnutls_dh_params_init(dh_params);
431
327
if (ret != GNUTLS_E_SUCCESS) {
432
328
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
433
329
" %s\n", safer_gnutls_strerror(ret));
436
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
332
ret = gnutls_dh_params_generate2(*dh_params, mc->dh_bits);
437
333
if (ret != GNUTLS_E_SUCCESS) {
438
334
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
439
335
safer_gnutls_strerror(ret));
443
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
static int init_gnutls_session(mandos_context *mc,
456
gnutls_session_t *session){
339
gnutls_certificate_set_dh_params(mc->cred, *dh_params);
458
341
/* GnuTLS session creation */
459
342
ret = gnutls_init(session, GNUTLS_SERVER);
460
343
if (ret != GNUTLS_E_SUCCESS){
817
688
const char *interface = "eth0";
818
689
struct ifreq network;
822
691
char *connect_to = NULL;
823
char tempdir[] = "/tmp/mandosXXXXXX";
824
692
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
825
const char *seckey = PATHDIR "/" SECKEY;
826
const char *pubkey = PATHDIR "/" PUBKEY;
828
693
mandos_context mc = { .simple_poll = NULL, .server = NULL,
829
.dh_bits = 1024, .priority = "SECURE256"
830
":!CTYPE-X.509:+CTYPE-OPENPGP" };
831
bool gnutls_initalized = false;
832
bool gpgme_initalized = false;
694
.dh_bits = 1024, .priority = "SECURE256"};
835
struct argp_option options[] = {
836
{ .name = "debug", .key = 128,
837
.doc = "Debug mode", .group = 3 },
838
{ .name = "connect", .key = 'c',
839
.arg = "ADDRESS:PORT",
840
.doc = "Connect directly to a specific Mandos server",
842
{ .name = "interface", .key = 'i',
844
.doc = "Interface that will be used to search for Mandos"
847
{ .name = "seckey", .key = 's',
849
.doc = "OpenPGP secret key file base name",
851
{ .name = "pubkey", .key = 'p',
853
.doc = "OpenPGP public key file base name",
855
{ .name = "dh-bits", .key = 129,
857
.doc = "Bit length of the prime number used in the"
858
" Diffie-Hellman key exchange",
860
{ .name = "priority", .key = 130,
862
.doc = "GnuTLS priority string for the TLS handshake",
867
error_t parse_opt (int key, char *arg,
868
struct argp_state *state) {
870
case 128: /* --debug */
873
case 'c': /* --connect */
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");
697
/* Temporary int to get the address of for getopt_long */
698
int debug_int = debug ? 1 : 0;
700
struct option long_options[] = {
701
{"debug", no_argument, &debug_int, 1},
702
{"connect", required_argument, NULL, 'c'},
703
{"interface", required_argument, NULL, 'i'},
704
{"keydir", required_argument, NULL, 'd'},
705
{"seckey", required_argument, NULL, 's'},
706
{"pubkey", required_argument, NULL, 'p'},
707
{"dh-bits", required_argument, NULL, 'D'},
708
{"priority", required_argument, NULL, 'P'},
711
int option_index = 0;
712
ret = getopt_long (argc, argv, "i:", long_options,
739
mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);
889
742
exit(EXIT_FAILURE);
892
case 130: /* --priority */
746
mc.priority = optarg;
900
return ARGP_ERR_UNKNOWN;
905
struct argp argp = { .options = options, .parser = parse_opt,
907
.doc = "Mandos client -- Get and decrypt"
908
" passwords from a Mandos server" };
909
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
910
if (ret == ARGP_ERR_UNKNOWN){
911
fprintf(stderr, "Unknown error while parsing arguments\n");
912
exitcode = EXIT_FAILURE;
917
/* If the interface is down, bring it up */
919
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
922
exitcode = EXIT_FAILURE;
925
strcpy(network.ifr_name, interface);
926
ret = ioctl(sd, SIOCGIFFLAGS, &network);
928
perror("ioctl SIOCGIFFLAGS");
929
exitcode = EXIT_FAILURE;
932
if((network.ifr_flags & IFF_UP) == 0){
933
network.ifr_flags |= IFF_UP;
934
ret = ioctl(sd, SIOCSIFFLAGS, &network);
936
perror("ioctl SIOCSIFFLAGS");
937
exitcode = EXIT_FAILURE;
941
ret = (int)TEMP_FAILURE_RETRY(close(sd));
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;
750
/* getopt_long() has already printed a message about the
751
unrcognized option, so just exit. */
755
/* Set the global debug flag from the temporary int */
756
debug = debug_int ? true : false;
759
pubkeyfile = combinepath(keydir, pubkeyfile);
760
if (pubkeyfile == NULL){
761
perror("combinepath");
762
exitcode = EXIT_FAILURE;
766
seckeyfile = combinepath(keydir, seckeyfile);
767
if (seckeyfile == NULL){
768
perror("combinepath");
983
772
if_index = (AvahiIfIndex) if_nametoindex(interface);
992
781
char *address = strrchr(connect_to, ':');
993
782
if(address == NULL){
994
783
fprintf(stderr, "No colon in address\n");
995
exitcode = EXIT_FAILURE;
999
ret = sscanf(address+1, "%" SCNu16, &port);
1001
fprintf(stderr, "Bad port number\n");
1002
exitcode = EXIT_FAILURE;
787
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
789
perror("Bad port number");
1005
792
*address = '\0';
1006
793
address = connect_to;
1007
794
ret = start_mandos_communication(address, port, if_index, &mc);
1009
exitcode = EXIT_FAILURE;
1011
exitcode = EXIT_SUCCESS;
802
/* If the interface is down, bring it up */
804
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
807
exitcode = EXIT_FAILURE;
810
strcpy(network.ifr_name, interface); /* Spurious warning */
811
ret = ioctl(sd, SIOCGIFFLAGS, &network);
813
perror("ioctl SIOCGIFFLAGS");
814
exitcode = EXIT_FAILURE;
817
if((network.ifr_flags & IFF_UP) == 0){
818
network.ifr_flags |= IFF_UP;
819
ret = ioctl(sd, SIOCSIFFLAGS, &network);
821
perror("ioctl SIOCSIFFLAGS");
822
exitcode = EXIT_FAILURE;