32
32
#define _LARGEFILE_SOURCE
33
33
#define _FILE_OFFSET_BITS 64
39
#include <net/if.h> /* if_nametoindex */
40
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
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() */
42
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
45
79
#include <avahi-core/core.h>
46
80
#include <avahi-core/lookup.h>
47
81
#include <avahi-core/log.h>
49
83
#include <avahi-common/malloc.h>
50
84
#include <avahi-common/error.h>
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 */
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 */
68
#include <errno.h> /* perror() */
96
#include <gpgme.h> /* All GPGME types, constants and
99
GPGME_PROTOCOL_OpenPGP,
74
102
#define BUFFER_SIZE 256
76
static const char *keydir = "/conf/conf.d/mandos";
77
static const char *pubkeyfile = "pubkey.txt";
78
static const char *seckeyfile = "seckey.txt";
104
#define PATHDIR "/conf/conf.d/mandos"
105
#define SECKEY "seckey.txt"
106
#define PUBKEY "pubkey.txt"
80
108
bool debug = false;
109
static const char mandos_protocol_version[] = "1";
110
const char *argp_program_version = "mandos-client " VERSION;
111
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
82
/* Used for passing in values through all the callback functions */
113
/* Used for passing in values through the Avahi callback functions */
84
115
AvahiSimplePoll *simple_poll;
85
116
AvahiServer *server;
86
117
gnutls_certificate_credentials_t cred;
87
118
unsigned int dh_bits;
119
gnutls_dh_params_t dh_params;
88
120
const char *priority;
125
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
126
* "buffer_capacity" is how much is currently allocated,
127
* "buffer_length" is how much is already used.
129
size_t adjustbuffer(char **buffer, size_t buffer_length,
130
size_t buffer_capacity){
131
if (buffer_length + BUFFER_SIZE > buffer_capacity){
132
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
136
buffer_capacity += BUFFER_SIZE;
138
return buffer_capacity;
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;
144
static bool init_gpgme(mandos_context *mc, const char *seckey,
145
const char *pubkey, const char *tempdir){
101
147
gpgme_error_t rc;
103
size_t plaintext_capacity = 0;
104
ssize_t plaintext_length = 0;
105
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);
108
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
187
fprintf(stderr, "Initialize gpgme\n");
114
193
if (rc != GPG_ERR_NO_ERROR){
115
194
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
116
195
gpgme_strsource(rc), gpgme_strerror(rc));
120
/* Set GPGME home directory for the OpenPGP engine only */
199
/* Set GPGME home directory for the OpenPGP engine only */
121
200
rc = gpgme_get_engine_info (&engine_info);
122
201
if (rc != GPG_ERR_NO_ERROR){
123
202
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
124
203
gpgme_strsource(rc), gpgme_strerror(rc));
127
206
while(engine_info != NULL){
128
207
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
129
208
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
130
engine_info->file_name, homedir);
209
engine_info->file_name, tempdir);
133
212
engine_info = engine_info->next;
135
214
if(engine_info == NULL){
136
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");
140
252
/* 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;
167
270
/* Decrypt data from the cryptotext data buffer to the plaintext
169
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
272
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
170
273
if (rc != GPG_ERR_NO_ERROR){
171
274
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
172
275
gpgme_strsource(rc), gpgme_strerror(rc));
173
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;
174
305
goto decrypt_end;
178
309
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;
210
312
/* Seek back to the beginning of the GPGME plaintext data buffer */
211
313
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
212
perror("pgpme_data_seek");
314
perror("gpgme_data_seek");
213
315
plaintext_length = -1;
214
316
goto decrypt_end;
217
319
*plaintext = NULL;
219
if (plaintext_length + BUFFER_SIZE
220
> (ssize_t) plaintext_capacity){
221
*plaintext = realloc(*plaintext, plaintext_capacity
223
if (*plaintext == NULL){
321
plaintext_capacity = adjustbuffer(plaintext,
322
(size_t)plaintext_length,
324
if (plaintext_capacity == 0){
325
perror("adjustbuffer");
225
326
plaintext_length = -1;
226
327
goto decrypt_end;
228
plaintext_capacity += BUFFER_SIZE;
231
330
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
300
400
/* OpenPGP credentials */
301
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
302
!= GNUTLS_E_SUCCESS) {
303
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
304
405
safer_gnutls_strerror(ret));
406
gnutls_global_deinit ();
309
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
310
" 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,
314
416
ret = gnutls_certificate_set_openpgp_key_file
315
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
417
(mc->cred, pubkeyfilename, seckeyfilename,
418
GNUTLS_OPENPGP_FMT_BASE64);
316
419
if (ret != GNUTLS_E_SUCCESS) {
318
421
"Error[%d] while reading the OpenPGP key pair ('%s',"
319
" '%s')\n", ret, pubkeyfile, seckeyfile);
320
fprintf(stdout, "The GnuTLS error is: %s\n",
422
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
423
fprintf(stderr, "The GnuTLS error is: %s\n",
321
424
safer_gnutls_strerror(ret));
325
428
/* GnuTLS server initialization */
326
ret = gnutls_dh_params_init(dh_params);
429
ret = gnutls_dh_params_init(&mc->dh_params);
327
430
if (ret != GNUTLS_E_SUCCESS) {
328
431
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
329
432
" %s\n", safer_gnutls_strerror(ret));
332
ret = gnutls_dh_params_generate2(*dh_params, mc->dh_bits);
435
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
333
436
if (ret != GNUTLS_E_SUCCESS) {
334
437
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
335
438
safer_gnutls_strerror(ret));
339
gnutls_certificate_set_dh_params(mc->cred, *dh_params);
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);
454
static int init_gnutls_session(mandos_context *mc,
455
gnutls_session_t *session){
341
457
/* GnuTLS session creation */
342
458
ret = gnutls_init(session, GNUTLS_SERVER);
343
459
if (ret != GNUTLS_E_SUCCESS){
688
815
const char *interface = "eth0";
689
816
struct ifreq network;
691
820
char *connect_to = NULL;
821
char tempdir[] = "/tmp/mandosXXXXXX";
692
822
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
823
const char *seckey = PATHDIR "/" SECKEY;
824
const char *pubkey = PATHDIR "/" PUBKEY;
693
826
mandos_context mc = { .simple_poll = NULL, .server = NULL,
694
.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;
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,
833
struct argp_option options[] = {
834
{ .name = "debug", .key = 128,
835
.doc = "Debug mode", .group = 3 },
836
{ .name = "connect", .key = 'c',
837
.arg = "ADDRESS:PORT",
838
.doc = "Connect directly to a specific Mandos server",
840
{ .name = "interface", .key = 'i',
842
.doc = "Interface that will be used to search for Mandos"
845
{ .name = "seckey", .key = 's',
847
.doc = "OpenPGP secret key file base name",
849
{ .name = "pubkey", .key = 'p',
851
.doc = "OpenPGP public key file base name",
853
{ .name = "dh-bits", .key = 129,
855
.doc = "Bit length of the prime number used in the"
856
" Diffie-Hellman key exchange",
858
{ .name = "priority", .key = 130,
860
.doc = "GnuTLS priority string for the TLS handshake",
865
error_t parse_opt (int key, char *arg,
866
struct argp_state *state) {
867
/* Get the INPUT argument from `argp_parse', which we know is
868
a pointer to our plugin list pointer. */
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 */
739
mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);
887
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
741
889
perror("strtol");
742
890
exit(EXIT_FAILURE);
746
mc.priority = optarg;
893
case 130: /* --priority */
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");
901
return ARGP_ERR_UNKNOWN;
906
struct argp argp = { .options = options, .parser = parse_opt,
908
.doc = "Mandos client -- Get and decrypt"
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));
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;
772
984
if_index = (AvahiIfIndex) if_nametoindex(interface);
781
993
char *address = strrchr(connect_to, ':');
782
994
if(address == NULL){
783
995
fprintf(stderr, "No colon in address\n");
996
exitcode = EXIT_FAILURE;
787
1000
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
789
1002
perror("Bad port number");
1003
exitcode = EXIT_FAILURE;
792
1006
*address = '\0';
793
1007
address = connect_to;
794
1008
ret = start_mandos_communication(address, port, if_index, &mc);
1010
exitcode = EXIT_FAILURE;
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;
1012
exitcode = EXIT_SUCCESS;