32
33
#define _LARGEFILE_SOURCE
33
34
#define _FILE_OFFSET_BITS 64
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
40
#include <stdint.h> /* uint16_t, uint32_t */
40
41
#include <stddef.h> /* NULL, size_t, ssize_t */
41
42
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
44
#include <stdbool.h> /* bool, true */
44
45
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), memcpy(), strcpy() */
46
strerror(), asprintf(), strcpy() */
46
47
#include <sys/ioctl.h> /* ioctl */
47
#include <net/if.h> /* ifreq, SIOCGIFFLAGS, SIOCSIFFLAGS,
49
48
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
49
sockaddr_in6, PF_INET6,
51
50
SOCK_STREAM, INET6_ADDRSTRLEN,
53
#include <inttypes.h> /* PRIu16 */
51
uid_t, gid_t, open(), opendir(), DIR */
52
#include <sys/stat.h> /* open() */
54
53
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
54
struct in6_addr, inet_pton(),
56
#include <fcntl.h> /* open() */
57
#include <dirent.h> /* opendir(), struct dirent, readdir() */
58
#include <inttypes.h> /* PRIu16 */
57
59
#include <assert.h> /* assert() */
58
60
#include <errno.h> /* perror(), errno */
59
61
#include <time.h> /* time() */
60
62
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
61
63
SIOCSIFFLAGS, if_indextoname(),
62
64
if_nametoindex(), IF_NAMESIZE */
65
#include <netinet/in.h>
63
66
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
64
67
getuid(), getgid(), setuid(),
66
#include <netinet/in.h>
67
69
#include <arpa/inet.h> /* inet_pton(), htons */
68
70
#include <iso646.h> /* not, and */
69
71
#include <argp.h> /* struct argp_option, error_t, struct
91
94
GNUTLS_OPENPGP_FMT_BASE64 */
94
#include <gpgme.h> /* All GPGME types, constants and functions
97
#include <gpgme.h> /* All GPGME types, constants and
96
100
GPGME_PROTOCOL_OpenPGP,
99
103
#define BUFFER_SIZE 256
105
#define PATHDIR "/conf/conf.d/mandos"
106
#define SECKEY "seckey.txt"
107
#define PUBKEY "pubkey.txt"
101
109
bool debug = false;
102
static const char *keydir = "/conf/conf.d/mandos";
103
110
static const char mandos_protocol_version[] = "1";
104
const char *argp_program_version = "password-request 1.0";
111
const char *argp_program_version = "mandos-client " VERSION;
105
112
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
107
114
/* Used for passing in values through the Avahi callback functions */
135
* Decrypt OpenPGP data using keyrings in HOMEDIR.
136
* Returns -1 on error
138
static ssize_t pgp_packet_decrypt (const char *cryptotext,
141
const char *homedir){
142
gpgme_data_t dh_crypto, dh_plain;
145
static bool init_gpgme(mandos_context *mc, const char *seckey,
146
const char *pubkey, const char *tempdir){
144
148
gpgme_error_t rc;
146
size_t plaintext_capacity = 0;
147
ssize_t plaintext_length = 0;
148
149
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 = 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 = TEMP_FAILURE_RETRY(close(fd));
183
gpgme_data_release(pgp_data);
151
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
188
fprintf(stderr, "Initialize gpgme\n");
157
194
if (rc != GPG_ERR_NO_ERROR){
158
195
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
159
196
gpgme_strsource(rc), gpgme_strerror(rc));
163
/* Set GPGME home directory for the OpenPGP engine only */
200
/* Set GPGME home directory for the OpenPGP engine only */
164
201
rc = gpgme_get_engine_info (&engine_info);
165
202
if (rc != GPG_ERR_NO_ERROR){
166
203
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
167
204
gpgme_strsource(rc), gpgme_strerror(rc));
170
207
while(engine_info != NULL){
171
208
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
172
209
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
173
engine_info->file_name, homedir);
210
engine_info->file_name, tempdir);
176
213
engine_info = engine_info->next;
178
215
if(engine_info == NULL){
179
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
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");
183
253
/* Create new GPGME data buffer from memory cryptotext */
201
/* Create new GPGME "context" */
202
rc = gpgme_new(&ctx);
203
if (rc != GPG_ERR_NO_ERROR){
204
fprintf(stderr, "bad gpgme_new: %s: %s\n",
205
gpgme_strsource(rc), gpgme_strerror(rc));
206
plaintext_length = -1;
210
271
/* Decrypt data from the cryptotext data buffer to the plaintext
212
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
273
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
213
274
if (rc != GPG_ERR_NO_ERROR){
214
275
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
215
276
gpgme_strsource(rc), gpgme_strerror(rc));
216
277
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;
217
306
goto decrypt_end;
221
310
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
225
gpgme_decrypt_result_t result;
226
result = gpgme_op_decrypt_result(ctx);
228
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
230
fprintf(stderr, "Unsupported algorithm: %s\n",
231
result->unsupported_algorithm);
232
fprintf(stderr, "Wrong key usage: %u\n",
233
result->wrong_key_usage);
234
if(result->file_name != NULL){
235
fprintf(stderr, "File name: %s\n", result->file_name);
237
gpgme_recipient_t recipient;
238
recipient = result->recipients;
240
while(recipient != NULL){
241
fprintf(stderr, "Public key algorithm: %s\n",
242
gpgme_pubkey_algo_name(recipient->pubkey_algo));
243
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
244
fprintf(stderr, "Secret key available: %s\n",
245
recipient->status == GPG_ERR_NO_SECKEY
247
recipient = recipient->next;
253
313
/* Seek back to the beginning of the GPGME plaintext data buffer */
254
314
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
255
perror("pgpme_data_seek");
315
perror("gpgme_data_seek");
256
316
plaintext_length = -1;
257
317
goto decrypt_end;
341
401
/* OpenPGP credentials */
342
402
gnutls_certificate_allocate_credentials(&mc->cred);
343
403
if (ret != GNUTLS_E_SUCCESS){
344
fprintf (stderr, "GnuTLS memory error: %s\n",
404
fprintf (stderr, "GnuTLS memory error: %s\n", /* Spurious
345
406
safer_gnutls_strerror(ret));
346
407
gnutls_global_deinit ();
351
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
352
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
412
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
413
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
356
417
ret = gnutls_certificate_set_openpgp_key_file
357
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
418
(mc->cred, pubkeyfilename, seckeyfilename,
419
GNUTLS_OPENPGP_FMT_BASE64);
358
420
if (ret != GNUTLS_E_SUCCESS) {
360
422
"Error[%d] while reading the OpenPGP key pair ('%s',"
361
" '%s')\n", ret, pubkeyfile, seckeyfile);
362
fprintf(stdout, "The GnuTLS error is: %s\n",
423
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
424
fprintf(stderr, "The GnuTLS error is: %s\n",
363
425
safer_gnutls_strerror(ret));
745
/* Combines file name and path and returns the malloced new
746
string. some sane checks could/should be added */
747
static const char *combinepath(const char *first, const char *second){
748
size_t f_len = strlen(first);
749
size_t s_len = strlen(second);
750
char *tmp = malloc(f_len + s_len + 2);
755
memcpy(tmp, first, f_len); /* Spurious warning */
759
memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */
761
tmp[f_len + 1 + s_len] = '\0';
766
811
int main(int argc, char *argv[]){
767
812
AvahiSServiceBrowser *sb = NULL;
776
821
char *connect_to = NULL;
822
char tempdir[] = "/tmp/mandosXXXXXX";
777
823
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
778
const char *pubkeyfile = "pubkey.txt";
779
const char *seckeyfile = "seckey.txt";
824
const char *seckey = PATHDIR "/" SECKEY;
825
const char *pubkey = PATHDIR "/" PUBKEY;
780
827
mandos_context mc = { .simple_poll = NULL, .server = NULL,
781
.dh_bits = 1024, .priority = "SECURE256"};
828
.dh_bits = 1024, .priority = "SECURE256"
829
":!CTYPE-X.509:+CTYPE-OPENPGP" };
782
830
bool gnutls_initalized = false;
831
bool gpgme_initalized = false;
785
834
struct argp_option options[] = {
786
835
{ .name = "debug", .key = 128,
787
836
.doc = "Debug mode", .group = 3 },
788
837
{ .name = "connect", .key = 'c',
790
.doc = "Connect directly to a sepcified mandos server",
838
.arg = "ADDRESS:PORT",
839
.doc = "Connect directly to a specific Mandos server",
792
841
{ .name = "interface", .key = 'i',
794
.doc = "Interface that Avahi will conntect through",
796
{ .name = "keydir", .key = 'd',
798
.doc = "Directory where the openpgp keyring is",
843
.doc = "Interface that will be used to search for Mandos"
800
846
{ .name = "seckey", .key = 's',
802
.doc = "Secret openpgp key for gnutls authentication",
848
.doc = "OpenPGP secret key file base name",
804
850
{ .name = "pubkey", .key = 'p',
806
.doc = "Public openpgp key for gnutls authentication",
852
.doc = "OpenPGP public key file base name",
808
854
{ .name = "dh-bits", .key = 129,
810
.doc = "dh-bits to use in gnutls communication",
856
.doc = "Bit length of the prime number used in the"
857
" Diffie-Hellman key exchange",
812
859
{ .name = "priority", .key = 130,
814
.doc = "GNUTLS priority", .group = 1 },
861
.doc = "GnuTLS priority string for the TLS handshake",
819
866
error_t parse_opt (int key, char *arg,
820
867
struct argp_state *state) {
821
868
/* Get the INPUT argument from `argp_parse', which we know is
822
869
a pointer to our plugin list pointer. */
871
case 128: /* --debug */
874
case 'c': /* --connect */
828
875
connect_to = arg;
877
case 'i': /* --interface */
880
case 's': /* --seckey */
883
case 'p': /* --pubkey */
886
case 129: /* --dh-bits */
844
888
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
847
891
exit(EXIT_FAILURE);
894
case 130: /* --priority */
851
895
mc.priority = arg;
853
897
case ARGP_KEY_ARG:
854
898
argp_usage (state);
859
902
return ARGP_ERR_UNKNOWN;
864
907
struct argp argp = { .options = options, .parser = parse_opt,
866
909
.doc = "Mandos client -- Get and decrypt"
867
" passwords from mandos server" };
910
" passwords from a Mandos server" };
868
911
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
869
912
if (ret == ARGP_ERR_UNKNOWN){
870
fprintf(stderr, "Unkown error while parsing arguments\n");
871
exitcode = EXIT_FAILURE;
876
pubkeyfile = combinepath(keydir, pubkeyfile);
877
if (pubkeyfile == NULL){
878
perror("combinepath");
879
exitcode = EXIT_FAILURE;
883
seckeyfile = combinepath(keydir, seckeyfile);
884
if (seckeyfile == NULL){
885
perror("combinepath");
889
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
891
fprintf(stderr, "init_gnutls_global\n");
894
gnutls_initalized = true;
913
fprintf(stderr, "Unknown error while parsing arguments\n");
914
exitcode = EXIT_FAILURE;
919
/* If the interface is down, bring it up */
921
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
924
exitcode = EXIT_FAILURE;
927
strcpy(network.ifr_name, interface);
928
ret = ioctl(sd, SIOCGIFFLAGS, &network);
930
perror("ioctl SIOCGIFFLAGS");
931
exitcode = EXIT_FAILURE;
934
if((network.ifr_flags & IFF_UP) == 0){
935
network.ifr_flags |= IFF_UP;
936
ret = ioctl(sd, SIOCSIFFLAGS, &network);
938
perror("ioctl SIOCSIFFLAGS");
939
exitcode = EXIT_FAILURE;
943
ret = TEMP_FAILURE_RETRY(close(sd));
900
952
ret = setuid(uid);
902
954
perror("setuid");
907
959
perror("setgid");
962
ret = init_gnutls_global(&mc, pubkey, seckey);
964
fprintf(stderr, "init_gnutls_global failed\n");
965
exitcode = EXIT_FAILURE;
968
gnutls_initalized = true;
971
if(mkdtemp(tempdir) == NULL){
977
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
978
fprintf(stderr, "gpgme_initalized failed\n");
979
exitcode = EXIT_FAILURE;
982
gpgme_initalized = true;
910
985
if_index = (AvahiIfIndex) if_nametoindex(interface);
911
986
if(if_index == 0){
912
987
fprintf(stderr, "No such interface: \"%s\"\n", interface);
943
/* If the interface is down, bring it up */
945
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
948
exitcode = EXIT_FAILURE;
951
strcpy(network.ifr_name, interface); /* Spurious warning */
952
ret = ioctl(sd, SIOCGIFFLAGS, &network);
954
perror("ioctl SIOCGIFFLAGS");
955
exitcode = EXIT_FAILURE;
958
if((network.ifr_flags & IFF_UP) == 0){
959
network.ifr_flags |= IFF_UP;
960
ret = ioctl(sd, SIOCSIFFLAGS, &network);
962
perror("ioctl SIOCSIFFLAGS");
963
exitcode = EXIT_FAILURE;
971
1019
avahi_set_log_function(empty_log);
991
1039
config.publish_addresses = 0;
992
1040
config.publish_workstation = 0;
993
1041
config.publish_domain = 0;
995
1043
/* Allocate a new server */
996
1044
mc.server = avahi_server_new(avahi_simple_poll_get
997
1045
(mc.simple_poll), &config, NULL,
1000
1048
/* Free the Avahi configuration data */
1001
1049
avahi_server_config_free(&config);
1042
1090
if (mc.server != NULL)
1043
1091
avahi_server_free(mc.server);
1045
1093
if (mc.simple_poll != NULL)
1046
1094
avahi_simple_poll_free(mc.simple_poll);
1050
1096
if (gnutls_initalized){
1051
1097
gnutls_certificate_free_credentials(mc.cred);
1052
1098
gnutls_global_deinit ();
1099
gnutls_dh_params_deinit(mc.dh_params);
1102
if(gpgme_initalized){
1103
gpgme_release(mc.ctx);
1106
/* Removes the temp directory used by GPGME */
1107
if(tempdir[0] != '\0'){
1109
struct dirent *direntry;
1110
d = opendir(tempdir);
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);
1055
1143
return exitcode;