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 */
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(),
53
#include <sys/stat.h> /* open() */
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
struct in6_addr, inet_pton(),
57
#include <fcntl.h> /* open() */
58
#include <dirent.h> /* opendir(), struct dirent, readdir()
60
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
61
#include <assert.h> /* assert() */
62
#include <errno.h> /* perror(), errno */
63
#include <time.h> /* time(), nanosleep() */
41
#include <net/if.h> /* if_nametoindex */
42
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
64
44
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
65
SIOCSIFFLAGS, if_indextoname(),
66
if_nametoindex(), IF_NAMESIZE */
67
#include <netinet/in.h>
68
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
69
getuid(), getgid(), setuid(),
71
#include <arpa/inet.h> /* inet_pton(), htons */
72
#include <iso646.h> /* not, and, or */
73
#include <argp.h> /* struct argp_option, error_t, struct
74
argp_state, struct argp,
75
argp_parse(), ARGP_KEY_ARG,
76
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
77
#include <sys/klog.h> /* klogctl() */
80
/* All Avahi types, constants and functions
83
47
#include <avahi-core/core.h>
84
48
#include <avahi-core/lookup.h>
85
49
#include <avahi-core/log.h>
87
51
#include <avahi-common/malloc.h>
88
52
#include <avahi-common/error.h>
91
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
94
init_gnutls_session(),
96
#include <gnutls/openpgp.h>
97
/* gnutls_certificate_set_openpgp_key_file(),
98
GNUTLS_OPENPGP_FMT_BASE64 */
54
/* Mandos client part */
55
#include <sys/types.h> /* socket(), inet_pton() */
56
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
57
struct in6_addr, inet_pton() */
58
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
59
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
61
#include <unistd.h> /* close() */
62
#include <netinet/in.h>
63
#include <stdbool.h> /* true */
64
#include <string.h> /* memset */
65
#include <arpa/inet.h> /* inet_pton() */
66
#include <iso646.h> /* not */
67
#include <net/if.h> /* IF_NAMESIZE */
68
#include <argp.h> /* struct argp_option,
69
struct argp_state, struct argp,
101
#include <gpgme.h> /* All GPGME types, constants and
104
GPGME_PROTOCOL_OpenPGP,
72
#include <errno.h> /* perror() */
107
75
#define BUFFER_SIZE 256
109
#define PATHDIR "/conf/conf.d/mandos"
110
#define SECKEY "seckey.txt"
111
#define PUBKEY "pubkey.txt"
113
77
bool debug = false;
78
static const char *keydir = "/conf/conf.d/mandos";
114
79
static const char mandos_protocol_version[] = "1";
115
const char *argp_program_version = "mandos-client " VERSION;
80
const char *argp_program_version = "mandosclient 0.9";
116
81
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
118
83
/* Used for passing in values through the Avahi callback functions */
111
* Decrypt OpenPGP data using keyrings in HOMEDIR.
112
* Returns -1 on error
149
static bool init_gpgme(mandos_context *mc, const char *seckey,
150
const char *pubkey, const char *tempdir){
114
static ssize_t pgp_packet_decrypt (const char *cryptotext,
117
const char *homedir){
118
gpgme_data_t dh_crypto, dh_plain;
152
120
gpgme_error_t rc;
122
size_t plaintext_capacity = 0;
123
ssize_t plaintext_length = 0;
153
124
gpgme_engine_info_t engine_info;
157
* Helper function to insert pub and seckey to the enigne keyring.
159
bool import_key(const char *filename){
161
gpgme_data_t pgp_data;
163
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
169
rc = gpgme_data_new_from_fd(&pgp_data, fd);
170
if(rc != GPG_ERR_NO_ERROR){
171
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
172
gpgme_strsource(rc), gpgme_strerror(rc));
176
rc = gpgme_op_import(mc->ctx, pgp_data);
177
if(rc != GPG_ERR_NO_ERROR){
178
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
179
gpgme_strsource(rc), gpgme_strerror(rc));
183
ret = (int)TEMP_FAILURE_RETRY(close(fd));
187
gpgme_data_release(pgp_data);
192
fprintf(stderr, "Initialize gpgme\n");
127
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
196
131
gpgme_check_version(NULL);
197
132
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
198
if(rc != GPG_ERR_NO_ERROR){
133
if (rc != GPG_ERR_NO_ERROR){
199
134
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
200
135
gpgme_strsource(rc), gpgme_strerror(rc));
204
/* Set GPGME home directory for the OpenPGP engine only */
205
rc = gpgme_get_engine_info(&engine_info);
206
if(rc != GPG_ERR_NO_ERROR){
139
/* Set GPGME home directory for the OpenPGP engine only */
140
rc = gpgme_get_engine_info (&engine_info);
141
if (rc != GPG_ERR_NO_ERROR){
207
142
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
208
143
gpgme_strsource(rc), gpgme_strerror(rc));
211
146
while(engine_info != NULL){
212
147
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
213
148
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
214
engine_info->file_name, tempdir);
149
engine_info->file_name, homedir);
217
152
engine_info = engine_info->next;
219
154
if(engine_info == NULL){
220
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
224
/* Create new GPGME "context" */
225
rc = gpgme_new(&(mc->ctx));
226
if(rc != GPG_ERR_NO_ERROR){
227
fprintf(stderr, "bad gpgme_new: %s: %s\n",
228
gpgme_strsource(rc), gpgme_strerror(rc));
232
if(not import_key(pubkey) or not import_key(seckey)){
240
* Decrypt OpenPGP data.
241
* Returns -1 on error
243
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
244
const char *cryptotext,
247
gpgme_data_t dh_crypto, dh_plain;
250
size_t plaintext_capacity = 0;
251
ssize_t plaintext_length = 0;
254
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
155
fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);
257
159
/* Create new GPGME data buffer from memory cryptotext */
258
160
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
260
if(rc != GPG_ERR_NO_ERROR){
162
if (rc != GPG_ERR_NO_ERROR){
261
163
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
262
164
gpgme_strsource(rc), gpgme_strerror(rc));
266
168
/* Create new empty GPGME data buffer for the plaintext */
267
169
rc = gpgme_data_new(&dh_plain);
268
if(rc != GPG_ERR_NO_ERROR){
170
if (rc != GPG_ERR_NO_ERROR){
269
171
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
270
172
gpgme_strsource(rc), gpgme_strerror(rc));
271
173
gpgme_data_release(dh_crypto);
177
/* Create new GPGME "context" */
178
rc = gpgme_new(&ctx);
179
if (rc != GPG_ERR_NO_ERROR){
180
fprintf(stderr, "bad gpgme_new: %s: %s\n",
181
gpgme_strsource(rc), gpgme_strerror(rc));
182
plaintext_length = -1;
275
186
/* Decrypt data from the cryptotext data buffer to the plaintext
277
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
278
if(rc != GPG_ERR_NO_ERROR){
188
rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);
189
if (rc != GPG_ERR_NO_ERROR){
279
190
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
280
191
gpgme_strsource(rc), gpgme_strerror(rc));
281
192
plaintext_length = -1;
283
gpgme_decrypt_result_t result;
284
result = gpgme_op_decrypt_result(mc->ctx);
286
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
288
fprintf(stderr, "Unsupported algorithm: %s\n",
289
result->unsupported_algorithm);
290
fprintf(stderr, "Wrong key usage: %u\n",
291
result->wrong_key_usage);
292
if(result->file_name != NULL){
293
fprintf(stderr, "File name: %s\n", result->file_name);
295
gpgme_recipient_t recipient;
296
recipient = result->recipients;
298
while(recipient != NULL){
299
fprintf(stderr, "Public key algorithm: %s\n",
300
gpgme_pubkey_algo_name(recipient->pubkey_algo));
301
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
302
fprintf(stderr, "Secret key available: %s\n",
303
recipient->status == GPG_ERR_NO_SECKEY
305
recipient = recipient->next;
310
193
goto decrypt_end;
314
197
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
201
gpgme_decrypt_result_t result;
202
result = gpgme_op_decrypt_result(ctx);
204
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
206
fprintf(stderr, "Unsupported algorithm: %s\n",
207
result->unsupported_algorithm);
208
fprintf(stderr, "Wrong key usage: %d\n",
209
result->wrong_key_usage);
210
if(result->file_name != NULL){
211
fprintf(stderr, "File name: %s\n", result->file_name);
213
gpgme_recipient_t recipient;
214
recipient = result->recipients;
216
while(recipient != NULL){
217
fprintf(stderr, "Public key algorithm: %s\n",
218
gpgme_pubkey_algo_name(recipient->pubkey_algo));
219
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
220
fprintf(stderr, "Secret key available: %s\n",
221
recipient->status == GPG_ERR_NO_SECKEY
223
recipient = recipient->next;
317
229
/* Seek back to the beginning of the GPGME plaintext data buffer */
318
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
319
perror("gpgme_data_seek");
230
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
231
perror("pgpme_data_seek");
320
232
plaintext_length = -1;
321
233
goto decrypt_end;
406
317
/* OpenPGP credentials */
407
gnutls_certificate_allocate_credentials(&mc->cred);
408
if(ret != GNUTLS_E_SUCCESS){
409
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
413
safer_gnutls_strerror(ret));
414
gnutls_global_deinit();
318
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
319
!= GNUTLS_E_SUCCESS) {
320
fprintf (stderr, "GnuTLS memory error: %s\n",
321
safer_gnutls_strerror(ret));
322
gnutls_global_deinit ();
419
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
420
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
327
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
328
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
424
332
ret = gnutls_certificate_set_openpgp_key_file
425
(mc->cred, pubkeyfilename, seckeyfilename,
426
GNUTLS_OPENPGP_FMT_BASE64);
427
if(ret != GNUTLS_E_SUCCESS) {
333
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
334
if (ret != GNUTLS_E_SUCCESS) {
429
336
"Error[%d] while reading the OpenPGP key pair ('%s',"
430
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
431
fprintf(stderr, "The GnuTLS error is: %s\n",
337
" '%s')\n", ret, pubkeyfile, seckeyfile);
338
fprintf(stdout, "The GnuTLS error is: %s\n",
432
339
safer_gnutls_strerror(ret));
436
343
/* GnuTLS server initialization */
437
344
ret = gnutls_dh_params_init(&mc->dh_params);
438
if(ret != GNUTLS_E_SUCCESS) {
439
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
440
" %s\n", safer_gnutls_strerror(ret));
345
if (ret != GNUTLS_E_SUCCESS) {
346
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
347
" %s\n", safer_gnutls_strerror(ret));
443
350
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
444
if(ret != GNUTLS_E_SUCCESS) {
445
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
446
safer_gnutls_strerror(ret));
351
if (ret != GNUTLS_E_SUCCESS) {
352
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
353
safer_gnutls_strerror(ret));
450
357
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
456
gnutls_certificate_free_credentials(mc->cred);
457
gnutls_global_deinit();
458
gnutls_dh_params_deinit(mc->dh_params);
363
gnutls_certificate_free_credentials (mc->cred);
364
gnutls_global_deinit ();
462
369
static int init_gnutls_session(mandos_context *mc,
833
746
char *connect_to = NULL;
834
char tempdir[] = "/tmp/mandosXXXXXX";
835
747
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
836
const char *seckey = PATHDIR "/" SECKEY;
837
const char *pubkey = PATHDIR "/" PUBKEY;
748
const char *pubkeyfile = "pubkey.txt";
749
const char *seckeyfile = "seckey.txt";
839
750
mandos_context mc = { .simple_poll = NULL, .server = NULL,
840
.dh_bits = 1024, .priority = "SECURE256"
841
":!CTYPE-X.509:+CTYPE-OPENPGP" };
751
.dh_bits = 1024, .priority = "SECURE256"};
842
752
bool gnutls_initalized = false;
843
bool gpgme_initalized = false;
847
755
struct argp_option options[] = {
848
756
{ .name = "debug", .key = 128,
849
757
.doc = "Debug mode", .group = 3 },
850
758
{ .name = "connect", .key = 'c',
851
.arg = "ADDRESS:PORT",
852
.doc = "Connect directly to a specific Mandos server",
760
.doc = "Connect directly to a sepcified mandos server",
854
762
{ .name = "interface", .key = 'i',
856
.doc = "Interface that will be used to search for Mandos"
764
.doc = "Interface that Avahi will conntect through",
766
{ .name = "keydir", .key = 'd',
768
.doc = "Directory where the openpgp keyring is",
859
770
{ .name = "seckey", .key = 's',
861
.doc = "OpenPGP secret key file base name",
772
.doc = "Secret openpgp key for gnutls authentication",
863
774
{ .name = "pubkey", .key = 'p',
865
.doc = "OpenPGP public key file base name",
776
.doc = "Public openpgp key for gnutls authentication",
867
778
{ .name = "dh-bits", .key = 129,
869
.doc = "Bit length of the prime number used in the"
870
" Diffie-Hellman key exchange",
780
.doc = "dh-bits to use in gnutls communication",
872
782
{ .name = "priority", .key = 130,
874
.doc = "GnuTLS priority string for the TLS handshake",
876
{ .name = "delay", .key = 131,
878
.doc = "Maximum delay to wait for interface startup",
784
.doc = "GNUTLS priority", .group = 1 },
883
error_t parse_opt(int key, char *arg,
884
struct argp_state *state) {
886
case 128: /* --debug */
789
error_t parse_opt (int key, char *arg,
790
struct argp_state *state) {
791
/* Get the INPUT argument from `argp_parse', which we know is
792
a pointer to our plugin list pointer. */
889
case 'c': /* --connect */
890
798
connect_to = arg;
892
case 'i': /* --interface */
895
case 's': /* --seckey */
898
case 'p': /* --pubkey */
901
case 129: /* --dh-bits */
902
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
903
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
904
or arg[numchars] != '\0'){
905
fprintf(stderr, "Bad number of DH bits\n");
814
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
906
817
exit(EXIT_FAILURE);
908
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
910
case 130: /* --priority */
911
821
mc.priority = arg;
913
case 131: /* --delay */
914
ret = sscanf(arg, "%lf%n", &delay, &numchars);
915
if(ret < 1 or arg[numchars] != '\0'){
916
fprintf(stderr, "Bad delay\n");
920
823
case ARGP_KEY_ARG:
925
829
return ARGP_ERR_UNKNOWN;
930
834
struct argp argp = { .options = options, .parser = parse_opt,
932
836
.doc = "Mandos client -- Get and decrypt"
933
" passwords from a Mandos server" };
934
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
935
if(ret == ARGP_ERR_UNKNOWN){
936
fprintf(stderr, "Unknown error while parsing arguments\n");
937
exitcode = EXIT_FAILURE;
942
/* If the interface is down, bring it up */
944
// Lower kernel loglevel to KERN_NOTICE to avoid
945
// KERN_INFO messages to mess up the prompt
946
ret = klogctl(8, NULL, 5);
951
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
954
exitcode = EXIT_FAILURE;
955
ret = klogctl(7, NULL, 0);
961
strcpy(network.ifr_name, interface);
962
ret = ioctl(sd, SIOCGIFFLAGS, &network);
964
perror("ioctl SIOCGIFFLAGS");
965
ret = klogctl(7, NULL, 0);
969
exitcode = EXIT_FAILURE;
972
if((network.ifr_flags & IFF_UP) == 0){
973
network.ifr_flags |= IFF_UP;
974
ret = ioctl(sd, SIOCSIFFLAGS, &network);
976
perror("ioctl SIOCSIFFLAGS");
977
exitcode = EXIT_FAILURE;
978
ret = klogctl(7, NULL, 0);
985
// sleep checking until interface is running
986
for(int i=0; i < delay * 4; i++){
987
ret = ioctl(sd, SIOCGIFFLAGS, &network);
989
perror("ioctl SIOCGIFFLAGS");
990
} else if(network.ifr_flags & IFF_RUNNING){
993
struct timespec sleeptime = { .tv_nsec = 250000000 };
994
nanosleep(&sleeptime, NULL);
996
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1000
// Restores kernel loglevel to default
1001
ret = klogctl(7, NULL, 0);
837
" passwords from mandos server" };
838
argp_parse (&argp, argc, argv, 0, 0, NULL);
841
pubkeyfile = combinepath(keydir, pubkeyfile);
842
if (pubkeyfile == NULL){
843
perror("combinepath");
844
exitcode = EXIT_FAILURE;
848
seckeyfile = combinepath(keydir, seckeyfile);
849
if (seckeyfile == NULL){
850
perror("combinepath");
854
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
856
fprintf(stderr, "init_gnutls_global\n");
859
gnutls_initalized = true;
1010
865
ret = setuid(uid);
1012
867
perror("setuid");
1017
872
perror("setgid");
1020
ret = init_gnutls_global(&mc, pubkey, seckey);
1022
fprintf(stderr, "init_gnutls_global failed\n");
1023
exitcode = EXIT_FAILURE;
1026
gnutls_initalized = true;
1029
if(mkdtemp(tempdir) == NULL){
1035
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1036
fprintf(stderr, "gpgme_initalized failed\n");
1037
exitcode = EXIT_FAILURE;
1040
gpgme_initalized = true;
1043
875
if_index = (AvahiIfIndex) if_nametoindex(interface);
1044
876
if(if_index == 0){
1045
877
fprintf(stderr, "No such interface: \"%s\"\n", interface);