31
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
32
34
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
33
37
#define _FILE_OFFSET_BITS 64
39
#include <net/if.h> /* if_nametoindex */
40
#include <sys/ioctl.h> // ioctl, ifreq, SIOCGIFFLAGS, IFF_UP, SIOCSIFFLAGS
41
#include <net/if.h> // ioctl, ifreq, SIOCGIFFLAGS, IFF_UP, SIOCSIFFLAGS
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t */
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
47
srand(), strtof(), abort() */
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open() */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
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SIOCSIFFLAGS, if_indextoname(),
69
if_nametoindex(), IF_NAMESIZE */
70
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
76
#include <arpa/inet.h> /* inet_pton(), htons */
77
#include <iso646.h> /* not, or, and */
78
#include <argp.h> /* struct argp_option, error_t, struct
79
argp_state, struct argp,
80
argp_parse(), ARGP_KEY_ARG,
81
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
#include <signal.h> /* sigemptyset(), sigaddset(),
83
sigaction(), SIGTERM, sig_atomic_t,
87
#include <sys/klog.h> /* klogctl() */
88
#endif /* __linux__ */
91
/* All Avahi types, constants and functions
43
94
#include <avahi-core/core.h>
44
95
#include <avahi-core/lookup.h>
45
96
#include <avahi-core/log.h>
47
98
#include <avahi-common/malloc.h>
48
99
#include <avahi-common/error.h>
51
#include <sys/types.h> /* socket(), inet_pton() */
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
struct in6_addr, inet_pton() */
54
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
55
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
57
#include <unistd.h> /* close() */
58
#include <netinet/in.h>
59
#include <stdbool.h> /* true */
60
#include <string.h> /* memset */
61
#include <arpa/inet.h> /* inet_pton() */
62
#include <iso646.h> /* not */
65
#include <errno.h> /* perror() */
102
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
105
init_gnutls_session(),
107
#include <gnutls/openpgp.h>
108
/* gnutls_certificate_set_openpgp_key_file(),
109
GNUTLS_OPENPGP_FMT_BASE64 */
112
#include <gpgme.h> /* All GPGME types, constants and
115
GPGME_PROTOCOL_OpenPGP,
71
118
#define BUFFER_SIZE 256
73
static const char *keydir = "/conf/conf.d/mandos";
74
static const char *pubkeyfile = "pubkey.txt";
75
static const char *seckeyfile = "seckey.txt";
120
#define PATHDIR "/conf/conf.d/mandos"
121
#define SECKEY "seckey.txt"
122
#define PUBKEY "pubkey.txt"
77
124
bool debug = false;
125
static const char mandos_protocol_version[] = "1";
126
const char *argp_program_version = "mandos-client " VERSION;
127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
79
/* Used for passing in values through all the callback functions */
129
/* Used for passing in values through the Avahi callback functions */
81
131
AvahiSimplePoll *simple_poll;
82
132
AvahiServer *server;
83
133
gnutls_certificate_credentials_t cred;
84
134
unsigned int dh_bits;
135
gnutls_dh_params_t dh_params;
85
136
const char *priority;
88
static ssize_t pgp_packet_decrypt (char *packet, size_t packet_size,
91
gpgme_data_t dh_crypto, dh_plain;
140
/* global context so signal handler can reach it*/
141
mandos_context mc = { .simple_poll = NULL, .server = NULL,
142
.dh_bits = 1024, .priority = "SECURE256"
143
":!CTYPE-X.509:+CTYPE-OPENPGP" };
145
sig_atomic_t quit_now = 0;
146
int signal_received = 0;
149
* Make additional room in "buffer" for at least BUFFER_SIZE more
150
* bytes. "buffer_capacity" is how much is currently allocated,
151
* "buffer_length" is how much is already used.
153
size_t incbuffer(char **buffer, size_t buffer_length,
154
size_t buffer_capacity){
155
if(buffer_length + BUFFER_SIZE > buffer_capacity){
156
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
160
buffer_capacity += BUFFER_SIZE;
162
return buffer_capacity;
168
static bool init_gpgme(const char *seckey,
169
const char *pubkey, const char *tempdir){
95
ssize_t new_packet_capacity = 0;
96
ssize_t new_packet_length = 0;
97
171
gpgme_engine_info_t engine_info;
100
fprintf(stderr, "Trying to decrypt OpenPGP packet\n");
175
* Helper function to insert pub and seckey to the engine keyring.
177
bool import_key(const char *filename){
180
gpgme_data_t pgp_data;
182
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
188
rc = gpgme_data_new_from_fd(&pgp_data, fd);
189
if(rc != GPG_ERR_NO_ERROR){
190
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
191
gpgme_strsource(rc), gpgme_strerror(rc));
195
rc = gpgme_op_import(mc.ctx, pgp_data);
196
if(rc != GPG_ERR_NO_ERROR){
197
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
198
gpgme_strsource(rc), gpgme_strerror(rc));
202
ret = (int)TEMP_FAILURE_RETRY(close(fd));
206
gpgme_data_release(pgp_data);
211
fprintf(stderr, "Initializing GPGME\n");
104
215
gpgme_check_version(NULL);
105
216
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
106
if (rc != GPG_ERR_NO_ERROR){
217
if(rc != GPG_ERR_NO_ERROR){
107
218
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
108
219
gpgme_strsource(rc), gpgme_strerror(rc));
112
/* Set GPGME home directory */
113
rc = gpgme_get_engine_info (&engine_info);
114
if (rc != GPG_ERR_NO_ERROR){
223
/* Set GPGME home directory for the OpenPGP engine only */
224
rc = gpgme_get_engine_info(&engine_info);
225
if(rc != GPG_ERR_NO_ERROR){
115
226
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
116
227
gpgme_strsource(rc), gpgme_strerror(rc));
119
230
while(engine_info != NULL){
120
231
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
121
232
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
122
engine_info->file_name, homedir);
233
engine_info->file_name, tempdir);
125
236
engine_info = engine_info->next;
127
238
if(engine_info == NULL){
128
fprintf(stderr, "Could not set home dir to %s\n", homedir);
132
/* Create new GPGME data buffer from packet buffer */
133
rc = gpgme_data_new_from_mem(&dh_crypto, packet, packet_size, 0);
134
if (rc != GPG_ERR_NO_ERROR){
239
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
243
/* Create new GPGME "context" */
244
rc = gpgme_new(&(mc.ctx));
245
if(rc != GPG_ERR_NO_ERROR){
246
fprintf(stderr, "bad gpgme_new: %s: %s\n",
247
gpgme_strsource(rc), gpgme_strerror(rc));
251
if(not import_key(pubkey) or not import_key(seckey)){
259
* Decrypt OpenPGP data.
260
* Returns -1 on error
262
static ssize_t pgp_packet_decrypt(const char *cryptotext,
265
gpgme_data_t dh_crypto, dh_plain;
268
size_t plaintext_capacity = 0;
269
ssize_t plaintext_length = 0;
272
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
275
/* Create new GPGME data buffer from memory cryptotext */
276
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
278
if(rc != GPG_ERR_NO_ERROR){
135
279
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
136
280
gpgme_strsource(rc), gpgme_strerror(rc));
198
/* Delete the GPGME FILE pointer cryptotext data buffer */
199
gpgme_data_release(dh_crypto);
330
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
201
333
/* Seek back to the beginning of the GPGME plaintext data buffer */
202
if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){
203
perror("pgpme_data_seek");
334
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
335
perror("gpgme_data_seek");
336
plaintext_length = -1;
208
if (new_packet_length + BUFFER_SIZE > new_packet_capacity){
209
*new_packet = realloc(*new_packet,
210
(unsigned int)new_packet_capacity
212
if (*new_packet == NULL){
216
new_packet_capacity += BUFFER_SIZE;
342
plaintext_capacity = incbuffer(plaintext,
343
(size_t)plaintext_length,
345
if(plaintext_capacity == 0){
347
plaintext_length = -1;
219
ret = gpgme_data_read(dh_plain, *new_packet + new_packet_length,
351
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
221
353
/* Print the data, if any */
226
359
perror("gpgme_data_read");
229
new_packet_length += ret;
232
/* FIXME: check characters before printing to screen so to not print
233
terminal control characters */
235
/* fprintf(stderr, "decrypted password is: "); */
236
/* fwrite(*new_packet, 1, new_packet_length, stderr); */
237
/* fprintf(stderr, "\n"); */
360
plaintext_length = -1;
363
plaintext_length += ret;
367
fprintf(stderr, "Decrypted password is: ");
368
for(ssize_t i = 0; i < plaintext_length; i++){
369
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
371
fprintf(stderr, "\n");
376
/* Delete the GPGME cryptotext data buffer */
377
gpgme_data_release(dh_crypto);
240
379
/* Delete the GPGME plaintext data buffer */
241
380
gpgme_data_release(dh_plain);
242
return new_packet_length;
381
return plaintext_length;
245
static const char * safer_gnutls_strerror (int value) {
246
const char *ret = gnutls_strerror (value);
384
static const char * safer_gnutls_strerror(int value){
385
const char *ret = gnutls_strerror(value); /* Spurious warning from
386
-Wunreachable-code */
248
388
ret = "(unknown)";
392
/* GnuTLS log function callback */
252
393
static void debuggnutls(__attribute__((unused)) int level,
253
394
const char* string){
254
fprintf(stderr, "%s", string);
395
fprintf(stderr, "GnuTLS: %s", string);
257
static int initgnutls(mandos_context *mc, gnutls_session_t *session,
258
gnutls_dh_params_t *dh_params){
398
static int init_gnutls_global(const char *pubkeyfilename,
399
const char *seckeyfilename){
263
403
fprintf(stderr, "Initializing GnuTLS\n");
266
if ((ret = gnutls_global_init ())
267
!= GNUTLS_E_SUCCESS) {
268
fprintf (stderr, "global_init: %s\n", safer_gnutls_strerror(ret));
406
ret = gnutls_global_init();
407
if(ret != GNUTLS_E_SUCCESS){
408
fprintf(stderr, "GnuTLS global_init: %s\n",
409
safer_gnutls_strerror(ret));
414
/* "Use a log level over 10 to enable all debugging options."
273
417
gnutls_global_set_log_level(11);
274
418
gnutls_global_set_log_function(debuggnutls);
277
/* openpgp credentials */
278
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
279
!= GNUTLS_E_SUCCESS) {
280
fprintf (stderr, "memory error: %s\n",
281
safer_gnutls_strerror(ret));
421
/* OpenPGP credentials */
422
gnutls_certificate_allocate_credentials(&mc.cred);
423
if(ret != GNUTLS_E_SUCCESS){
424
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
428
safer_gnutls_strerror(ret));
429
gnutls_global_deinit();
286
fprintf(stderr, "Attempting to use OpenPGP certificate %s"
287
" and keyfile %s as GnuTLS credentials\n", pubkeyfile,
434
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
435
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
291
439
ret = gnutls_certificate_set_openpgp_key_file
292
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
293
if (ret != GNUTLS_E_SUCCESS) {
295
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s',"
297
ret, pubkeyfile, seckeyfile);
298
fprintf(stdout, "The Error is: %s\n",
299
safer_gnutls_strerror(ret));
303
//GnuTLS server initialization
304
if ((ret = gnutls_dh_params_init(dh_params))
305
!= GNUTLS_E_SUCCESS) {
306
fprintf (stderr, "Error in dh parameter initialization: %s\n",
307
safer_gnutls_strerror(ret));
311
if ((ret = gnutls_dh_params_generate2(*dh_params, mc->dh_bits))
312
!= GNUTLS_E_SUCCESS) {
313
fprintf (stderr, "Error in prime generation: %s\n",
314
safer_gnutls_strerror(ret));
318
gnutls_certificate_set_dh_params(mc->cred, *dh_params);
320
// GnuTLS session creation
321
if ((ret = gnutls_init(session, GNUTLS_SERVER))
322
!= GNUTLS_E_SUCCESS){
440
(mc.cred, pubkeyfilename, seckeyfilename,
441
GNUTLS_OPENPGP_FMT_BASE64);
442
if(ret != GNUTLS_E_SUCCESS){
444
"Error[%d] while reading the OpenPGP key pair ('%s',"
445
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
446
fprintf(stderr, "The GnuTLS error is: %s\n",
447
safer_gnutls_strerror(ret));
451
/* GnuTLS server initialization */
452
ret = gnutls_dh_params_init(&mc.dh_params);
453
if(ret != GNUTLS_E_SUCCESS){
454
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
455
" %s\n", safer_gnutls_strerror(ret));
458
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
459
if(ret != GNUTLS_E_SUCCESS){
460
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
461
safer_gnutls_strerror(ret));
465
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
471
gnutls_certificate_free_credentials(mc.cred);
472
gnutls_global_deinit();
473
gnutls_dh_params_deinit(mc.dh_params);
477
static int init_gnutls_session(gnutls_session_t *session){
479
/* GnuTLS session creation */
481
ret = gnutls_init(session, GNUTLS_SERVER);
485
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
486
if(ret != GNUTLS_E_SUCCESS){
323
487
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
324
488
safer_gnutls_strerror(ret));
327
if ((ret = gnutls_priority_set_direct(*session, mc->priority, &err))
328
!= GNUTLS_E_SUCCESS) {
329
fprintf(stderr, "Syntax error at: %s\n", err);
330
fprintf(stderr, "GnuTLS error: %s\n",
331
safer_gnutls_strerror(ret));
494
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
496
gnutls_deinit(*session);
499
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
500
if(ret != GNUTLS_E_SUCCESS){
501
fprintf(stderr, "Syntax error at: %s\n", err);
502
fprintf(stderr, "GnuTLS error: %s\n",
503
safer_gnutls_strerror(ret));
504
gnutls_deinit(*session);
335
if ((ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
337
!= GNUTLS_E_SUCCESS) {
338
fprintf(stderr, "Error setting a credentials set: %s\n",
510
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
513
gnutls_deinit(*session);
516
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
517
if(ret != GNUTLS_E_SUCCESS){
518
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
339
519
safer_gnutls_strerror(ret));
520
gnutls_deinit(*session);
343
524
/* ignore client certificate if any. */
344
gnutls_certificate_server_set_request (*session,
525
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
347
gnutls_dh_set_prime_bits (*session, mc->dh_bits);
527
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
532
/* Avahi log function callback */
352
533
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
353
534
__attribute__((unused)) const char *txt){}
536
/* Called when a Mandos server is found */
355
537
static int start_mandos_communication(const char *ip, uint16_t port,
356
538
AvahiIfIndex if_index,
359
struct sockaddr_in6 to;
540
int ret, tcp_sd = -1;
543
struct sockaddr_in in;
544
struct sockaddr_in6 in6;
360
546
char *buffer = NULL;
361
char *decrypted_buffer;
547
char *decrypted_buffer = NULL;
362
548
size_t buffer_length = 0;
363
549
size_t buffer_capacity = 0;
364
ssize_t decrypted_buffer_size;
367
char interface[IF_NAMESIZE];
368
552
gnutls_session_t session;
369
gnutls_dh_params_t dh_params;
553
int pf; /* Protocol family */
567
fprintf(stderr, "Bad address family: %d\n", af);
571
ret = init_gnutls_session(&session);
372
fprintf(stderr, "Setting up a tcp connection to %s, port %d\n",
577
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
376
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
581
tcp_sd = socket(pf, SOCK_STREAM, 0);
378
583
perror("socket");
383
if(if_indextoname((unsigned int)if_index, interface) == NULL){
384
perror("if_indextoname");
387
fprintf(stderr, "Binding to interface %s\n", interface);
390
memset(&to,0,sizeof(to)); /* Spurious warning */
391
to.sin6_family = AF_INET6;
392
ret = inet_pton(AF_INET6, ip, &to.sin6_addr);
591
memset(&to, 0, sizeof(to));
593
to.in6.sin6_family = (sa_family_t)af;
594
ret = inet_pton(af, ip, &to.in6.sin6_addr);
596
to.in.sin_family = (sa_family_t)af;
597
ret = inet_pton(af, ip, &to.in.sin_addr);
394
600
perror("inet_pton");
398
604
fprintf(stderr, "Bad address: %s\n", ip);
401
to.sin6_port = htons(port); /* Spurious warning */
608
to.in6.sin6_port = htons(port); /* Spurious warnings from
610
-Wunreachable-code */
612
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
613
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
615
if(if_index == AVAHI_IF_UNSPEC){
616
fprintf(stderr, "An IPv6 link-local address is incomplete"
617
" without a network interface\n");
620
/* Set the network interface number as scope */
621
to.in6.sin6_scope_id = (uint32_t)if_index;
624
to.in.sin_port = htons(port); /* Spurious warnings from
626
-Wunreachable-code */
403
to.sin6_scope_id = (uint32_t)if_index;
406
fprintf(stderr, "Connection to: %s, port %d\n", ip, port);
407
char addrstr[INET6_ADDRSTRLEN] = "";
408
if(inet_ntop(to.sin6_family, &(to.sin6_addr), addrstr,
409
sizeof(addrstr)) == NULL){
634
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
635
char interface[IF_NAMESIZE];
636
if(if_indextoname((unsigned int)if_index, interface) == NULL){
637
perror("if_indextoname");
639
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
640
ip, interface, port);
643
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
646
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
647
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
650
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
653
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
410
657
perror("inet_ntop");
412
659
if(strcmp(addrstr, ip) != 0){
418
ret = connect(tcp_sd, (struct sockaddr *) &to, sizeof(to));
670
ret = connect(tcp_sd, &to.in6, sizeof(to));
672
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
420
675
perror("connect");
424
ret = initgnutls (mc, &session, &dh_params);
430
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
683
const char *out = mandos_protocol_version;
686
size_t out_size = strlen(out);
687
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
688
out_size - written));
693
written += (size_t)ret;
694
if(written < out_size){
697
if(out == mandos_protocol_version){
433
711
fprintf(stderr, "Establishing TLS session with %s\n", ip);
436
ret = gnutls_handshake (session);
438
if (ret != GNUTLS_E_SUCCESS){
718
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
725
ret = gnutls_handshake(session);
729
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
731
if(ret != GNUTLS_E_SUCCESS){
440
fprintf(stderr, "\n*** Handshake failed ***\n");
733
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
447
//Retrieve OpenPGP packet that contains the wanted password
739
/* Read OpenPGP packet that contains the wanted password */
450
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
742
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
455
if (buffer_length + BUFFER_SIZE > buffer_capacity){
456
buffer = realloc(buffer, buffer_capacity + BUFFER_SIZE);
461
buffer_capacity += BUFFER_SIZE;
464
ret = gnutls_record_recv(session, buffer+buffer_length,
752
buffer_capacity = incbuffer(&buffer, buffer_length,
754
if(buffer_capacity == 0){
763
sret = gnutls_record_recv(session, buffer+buffer_length,
471
770
case GNUTLS_E_INTERRUPTED:
472
771
case GNUTLS_E_AGAIN:
474
773
case GNUTLS_E_REHANDSHAKE:
475
ret = gnutls_handshake (session);
477
fprintf(stderr, "\n*** Handshake failed ***\n");
775
ret = gnutls_handshake(session);
780
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
782
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
484
788
fprintf(stderr, "Unknown error while reading data from"
485
" encrypted session with mandos server\n");
487
gnutls_bye (session, GNUTLS_SHUT_RDWR);
789
" encrypted session with Mandos server\n");
790
gnutls_bye(session, GNUTLS_SHUT_RDWR);
491
buffer_length += (size_t) ret;
495
if (buffer_length > 0){
794
buffer_length += (size_t) sret;
799
fprintf(stderr, "Closing TLS session\n");
807
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
811
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
813
if(buffer_length > 0){
814
ssize_t decrypted_buffer_size;
496
815
decrypted_buffer_size = pgp_packet_decrypt(buffer,
500
if (decrypted_buffer_size >= 0){
818
if(decrypted_buffer_size >= 0){
501
821
while(written < (size_t) decrypted_buffer_size){
502
ret = (int)fwrite (decrypted_buffer + written, 1,
503
(size_t)decrypted_buffer_size - written,
826
ret = (int)fwrite(decrypted_buffer + written, 1,
827
(size_t)decrypted_buffer_size - written,
505
829
if(ret == 0 and ferror(stdout)){
507
831
fprintf(stderr, "Error writing encrypted data: %s\n",
508
832
strerror(errno));
513
836
written += (size_t)ret;
515
free(decrypted_buffer);
524
fprintf(stderr, "Closing TLS session\n");
842
/* Shutdown procedure */
845
free(decrypted_buffer);
528
gnutls_bye (session, GNUTLS_SHUT_RDWR);
531
gnutls_deinit (session);
532
gnutls_certificate_free_credentials (mc->cred);
533
gnutls_global_deinit ();
848
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
853
gnutls_deinit(session);
537
static void resolve_callback( AvahiSServiceResolver *r,
538
AvahiIfIndex interface,
539
AVAHI_GCC_UNUSED AvahiProtocol protocol,
540
AvahiResolverEvent event,
544
const char *host_name,
545
const AvahiAddress *address,
547
AVAHI_GCC_UNUSED AvahiStringList *txt,
548
AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
550
mandos_context *mc = userdata;
551
assert(r); /* Spurious warning */
860
static void resolve_callback(AvahiSServiceResolver *r,
861
AvahiIfIndex interface,
863
AvahiResolverEvent event,
867
const char *host_name,
868
const AvahiAddress *address,
870
AVAHI_GCC_UNUSED AvahiStringList *txt,
871
AVAHI_GCC_UNUSED AvahiLookupResultFlags
873
AVAHI_GCC_UNUSED void* userdata){
553
876
/* Called whenever a service has been resolved successfully or
558
885
case AVAHI_RESOLVER_FAILURE:
559
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of"
560
" type '%s' in domain '%s': %s\n", name, type, domain,
561
avahi_strerror(avahi_server_errno(mc->server)));
886
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
887
" of type '%s' in domain '%s': %s\n", name, type, domain,
888
avahi_strerror(avahi_server_errno(mc.server)));
564
891
case AVAHI_RESOLVER_FOUND:
622
954
case AVAHI_BROWSER_ALL_FOR_NOW:
623
955
case AVAHI_BROWSER_CACHE_EXHAUSTED:
957
fprintf(stderr, "No Mandos server found, still searching...\n");
628
/* Combines file name and path and returns the malloced new
629
string. some sane checks could/should be added */
630
static const char *combinepath(const char *first, const char *second){
631
size_t f_len = strlen(first);
632
size_t s_len = strlen(second);
633
char *tmp = malloc(f_len + s_len + 2);
638
memcpy(tmp, first, f_len); /* Spurious warning */
642
memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */
644
tmp[f_len + 1 + s_len] = '\0';
963
/* stop main loop after sigterm has been called */
964
static void handle_sigterm(int sig){
969
signal_received = sig;
970
int old_errno = errno;
971
if(mc.simple_poll != NULL){
972
avahi_simple_poll_quit(mc.simple_poll);
649
int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char*argv[]) {
650
AvahiServerConfig config;
651
AvahiSServiceBrowser *sb = NULL;
655
int returncode = EXIT_SUCCESS;
656
const char *interface = "eth0";
657
struct ifreq network;
659
char *connect_to = NULL;
660
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
661
mandos_context mc = { .simple_poll = NULL, .server = NULL,
662
.dh_bits = 1024, .priority = "SECURE256"};
977
int main(int argc, char *argv[]){
978
AvahiSServiceBrowser *sb = NULL;
983
int exitcode = EXIT_SUCCESS;
984
const char *interface = "eth0";
985
struct ifreq network;
987
bool take_down_interface = false;
990
char *connect_to = NULL;
991
char tempdir[] = "/tmp/mandosXXXXXX";
992
bool tempdir_created = false;
993
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
994
const char *seckey = PATHDIR "/" SECKEY;
995
const char *pubkey = PATHDIR "/" PUBKEY;
997
bool gnutls_initialized = false;
998
bool gpgme_initialized = false;
1001
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1002
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1007
/* Lower any group privileges we might have, just to be safe */
1014
/* Lower user privileges (temporarily) */
1026
struct argp_option options[] = {
1027
{ .name = "debug", .key = 128,
1028
.doc = "Debug mode", .group = 3 },
1029
{ .name = "connect", .key = 'c',
1030
.arg = "ADDRESS:PORT",
1031
.doc = "Connect directly to a specific Mandos server",
1033
{ .name = "interface", .key = 'i',
1035
.doc = "Network interface that will be used to search for"
1038
{ .name = "seckey", .key = 's',
1040
.doc = "OpenPGP secret key file base name",
1042
{ .name = "pubkey", .key = 'p',
1044
.doc = "OpenPGP public key file base name",
1046
{ .name = "dh-bits", .key = 129,
1048
.doc = "Bit length of the prime number used in the"
1049
" Diffie-Hellman key exchange",
1051
{ .name = "priority", .key = 130,
1053
.doc = "GnuTLS priority string for the TLS handshake",
1055
{ .name = "delay", .key = 131,
1057
.doc = "Maximum delay to wait for interface startup",
664
debug_int = debug ? 1 : 0;
666
struct option long_options[] = {
667
{"debug", no_argument, &debug_int, 1},
668
{"connect", required_argument, NULL, 'c'},
669
{"interface", required_argument, NULL, 'i'},
670
{"keydir", required_argument, NULL, 'd'},
671
{"seckey", required_argument, NULL, 's'},
672
{"pubkey", required_argument, NULL, 'p'},
673
{"dh-bits", required_argument, NULL, 'D'},
674
{"priority", required_argument, NULL, 'P'},
677
int option_index = 0;
678
ret = getopt_long (argc, argv, "i:", long_options,
705
mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);
712
mc.priority = optarg;
1062
error_t parse_opt(int key, char *arg,
1063
struct argp_state *state){
1065
case 128: /* --debug */
1068
case 'c': /* --connect */
1071
case 'i': /* --interface */
1074
case 's': /* --seckey */
1077
case 'p': /* --pubkey */
1080
case 129: /* --dh-bits */
1082
tmpmax = strtoimax(arg, &tmp, 10);
1083
if(errno != 0 or tmp == arg or *tmp != '\0'
1084
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1085
fprintf(stderr, "Bad number of DH bits\n");
1088
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1090
case 130: /* --priority */
1093
case 131: /* --delay */
1095
delay = strtof(arg, &tmp);
1096
if(errno != 0 or tmp == arg or *tmp != '\0'){
1097
fprintf(stderr, "Bad delay\n");
1106
return ARGP_ERR_UNKNOWN;
719
debug = debug_int ? true : false;
721
pubkeyfile = combinepath(keydir, pubkeyfile);
722
if (pubkeyfile == NULL){
723
perror("combinepath");
724
returncode = EXIT_FAILURE;
728
seckeyfile = combinepath(keydir, seckeyfile);
729
if (seckeyfile == NULL){
730
perror("combinepath");
1111
struct argp argp = { .options = options, .parser = parse_opt,
1113
.doc = "Mandos client -- Get and decrypt"
1114
" passwords from a Mandos server" };
1115
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1116
if(ret == ARGP_ERR_UNKNOWN){
1117
fprintf(stderr, "Unknown error while parsing arguments\n");
1118
exitcode = EXIT_FAILURE;
1124
avahi_set_log_function(empty_log);
1127
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1128
from the signal handler */
1129
/* Initialize the pseudo-RNG for Avahi */
1130
srand((unsigned int) time(NULL));
1131
mc.simple_poll = avahi_simple_poll_new();
1132
if(mc.simple_poll == NULL){
1133
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1134
exitcode = EXIT_FAILURE;
1138
sigemptyset(&sigterm_action.sa_mask);
1139
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1141
perror("sigaddset");
1142
exitcode = EXIT_FAILURE;
1145
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1147
perror("sigaddset");
1148
exitcode = EXIT_FAILURE;
1151
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1153
perror("sigaddset");
1154
exitcode = EXIT_FAILURE;
1157
/* Need to check if the handler is SIG_IGN before handling:
1158
| [[info:libc:Initial Signal Actions]] |
1159
| [[info:libc:Basic Signal Handling]] |
1161
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1163
perror("sigaction");
1164
return EXIT_FAILURE;
1166
if(old_sigterm_action.sa_handler != SIG_IGN){
1167
ret = sigaction(SIGINT, &sigterm_action, NULL);
1169
perror("sigaction");
1170
exitcode = EXIT_FAILURE;
1174
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1176
perror("sigaction");
1177
return EXIT_FAILURE;
1179
if(old_sigterm_action.sa_handler != SIG_IGN){
1180
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1182
perror("sigaction");
1183
exitcode = EXIT_FAILURE;
1187
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1189
perror("sigaction");
1190
return EXIT_FAILURE;
1192
if(old_sigterm_action.sa_handler != SIG_IGN){
1193
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1195
perror("sigaction");
1196
exitcode = EXIT_FAILURE;
1201
/* If the interface is down, bring it up */
1202
if(interface[0] != '\0'){
734
1203
if_index = (AvahiIfIndex) if_nametoindex(interface);
735
1204
if(if_index == 0){
736
1205
fprintf(stderr, "No such interface: \"%s\"\n", interface);
740
if(connect_to != NULL){
741
/* Connect directly, do not use Zeroconf */
742
/* (Mainly meant for debugging) */
743
char *address = strrchr(connect_to, ':');
745
fprintf(stderr, "No colon in address\n");
749
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
751
perror("Bad port number");
755
address = connect_to;
756
ret = start_mandos_communication(address, port, if_index, &mc);
1206
exitcode = EXIT_FAILURE;
1214
/* Re-raise priviliges */
1222
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1223
messages to mess up the prompt */
1224
ret = klogctl(8, NULL, 5);
1225
bool restore_loglevel = true;
1227
restore_loglevel = false;
1230
#endif /* __linux__ */
764
1232
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
766
1234
perror("socket");
767
returncode = EXIT_FAILURE;
1235
exitcode = EXIT_FAILURE;
1237
if(restore_loglevel){
1238
ret = klogctl(7, NULL, 0);
1243
#endif /* __linux__ */
1244
/* Lower privileges */
770
strcpy(network.ifr_name, interface); /* Spurious warning */
1252
strcpy(network.ifr_name, interface);
771
1253
ret = ioctl(sd, SIOCGIFFLAGS, &network);
774
1255
perror("ioctl SIOCGIFFLAGS");
775
returncode = EXIT_FAILURE;
1257
if(restore_loglevel){
1258
ret = klogctl(7, NULL, 0);
1263
#endif /* __linux__ */
1264
exitcode = EXIT_FAILURE;
1265
/* Lower privileges */
778
1273
if((network.ifr_flags & IFF_UP) == 0){
779
1274
network.ifr_flags |= IFF_UP;
1275
take_down_interface = true;
780
1276
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1278
take_down_interface = false;
782
1279
perror("ioctl SIOCSIFFLAGS");
783
returncode = EXIT_FAILURE;
790
avahi_set_log_function(empty_log);
793
/* Initialize the psuedo-RNG */
794
srand((unsigned int) time(NULL));
796
/* Allocate main loop object */
797
if (!(mc.simple_poll = avahi_simple_poll_new())) {
798
fprintf(stderr, "Failed to create simple poll object.\n");
799
returncode = EXIT_FAILURE;
803
/* Do not publish any local records */
1280
exitcode = EXIT_FAILURE;
1282
if(restore_loglevel){
1283
ret = klogctl(7, NULL, 0);
1288
#endif /* __linux__ */
1289
/* Lower privileges */
1298
/* sleep checking until interface is running */
1299
for(int i=0; i < delay * 4; i++){
1300
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1302
perror("ioctl SIOCGIFFLAGS");
1303
} else if(network.ifr_flags & IFF_RUNNING){
1306
struct timespec sleeptime = { .tv_nsec = 250000000 };
1307
ret = nanosleep(&sleeptime, NULL);
1308
if(ret == -1 and errno != EINTR){
1309
perror("nanosleep");
1312
if(not take_down_interface){
1313
/* We won't need the socket anymore */
1314
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1320
if(restore_loglevel){
1321
/* Restores kernel loglevel to default */
1322
ret = klogctl(7, NULL, 0);
1327
#endif /* __linux__ */
1328
/* Lower privileges */
1330
if(take_down_interface){
1331
/* Lower privileges */
1337
/* Lower privileges permanently */
1349
ret = init_gnutls_global(pubkey, seckey);
1351
fprintf(stderr, "init_gnutls_global failed\n");
1352
exitcode = EXIT_FAILURE;
1355
gnutls_initialized = true;
1362
tempdir_created = true;
1363
if(mkdtemp(tempdir) == NULL){
1364
tempdir_created = false;
1373
if(not init_gpgme(pubkey, seckey, tempdir)){
1374
fprintf(stderr, "init_gpgme failed\n");
1375
exitcode = EXIT_FAILURE;
1378
gpgme_initialized = true;
1385
if(connect_to != NULL){
1386
/* Connect directly, do not use Zeroconf */
1387
/* (Mainly meant for debugging) */
1388
char *address = strrchr(connect_to, ':');
1389
if(address == NULL){
1390
fprintf(stderr, "No colon in address\n");
1391
exitcode = EXIT_FAILURE;
1401
tmpmax = strtoimax(address+1, &tmp, 10);
1402
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1403
or tmpmax != (uint16_t)tmpmax){
1404
fprintf(stderr, "Bad port number\n");
1405
exitcode = EXIT_FAILURE;
1413
port = (uint16_t)tmpmax;
1415
address = connect_to;
1416
/* Colon in address indicates IPv6 */
1418
if(strchr(address, ':') != NULL){
1428
ret = start_mandos_communication(address, port, if_index, af);
1430
exitcode = EXIT_FAILURE;
1432
exitcode = EXIT_SUCCESS;
1442
AvahiServerConfig config;
1443
/* Do not publish any local Zeroconf records */
804
1444
avahi_server_config_init(&config);
805
1445
config.publish_hinfo = 0;
806
1446
config.publish_addresses = 0;
807
1447
config.publish_workstation = 0;
808
1448
config.publish_domain = 0;
810
1450
/* Allocate a new server */
811
mc.server=avahi_server_new(avahi_simple_poll_get(mc.simple_poll),
812
&config, NULL, NULL, &error);
1451
mc.server = avahi_server_new(avahi_simple_poll_get
1452
(mc.simple_poll), &config, NULL,
814
/* Free the configuration data */
1455
/* Free the Avahi configuration data */
815
1456
avahi_server_config_free(&config);
817
/* Check if creating the server object succeeded */
819
fprintf(stderr, "Failed to create server: %s\n",
820
avahi_strerror(error));
821
returncode = EXIT_FAILURE;
825
/* Create the service browser */
826
sb = avahi_s_service_browser_new(mc.server, if_index,
828
"_mandos._tcp", NULL, 0,
829
browse_callback, &mc);
831
fprintf(stderr, "Failed to create service browser: %s\n",
832
avahi_strerror(avahi_server_errno(mc.server)));
833
returncode = EXIT_FAILURE;
837
/* Run the main loop */
840
fprintf(stderr, "Starting avahi loop search\n");
843
avahi_simple_poll_loop(mc.simple_poll);
848
fprintf(stderr, "%s exiting\n", argv[0]);
853
avahi_s_service_browser_free(sb);
856
avahi_server_free(mc.server);
859
avahi_simple_poll_free(mc.simple_poll);
1459
/* Check if creating the Avahi server object succeeded */
1460
if(mc.server == NULL){
1461
fprintf(stderr, "Failed to create Avahi server: %s\n",
1462
avahi_strerror(error));
1463
exitcode = EXIT_FAILURE;
1471
/* Create the Avahi service browser */
1472
sb = avahi_s_service_browser_new(mc.server, if_index,
1473
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1474
NULL, 0, browse_callback, NULL);
1476
fprintf(stderr, "Failed to create service browser: %s\n",
1477
avahi_strerror(avahi_server_errno(mc.server)));
1478
exitcode = EXIT_FAILURE;
1486
/* Run the main loop */
1489
fprintf(stderr, "Starting Avahi loop search\n");
1492
avahi_simple_poll_loop(mc.simple_poll);
1497
fprintf(stderr, "%s exiting\n", argv[0]);
1500
/* Cleanup things */
1502
avahi_s_service_browser_free(sb);
1504
if(mc.server != NULL)
1505
avahi_server_free(mc.server);
1507
if(mc.simple_poll != NULL)
1508
avahi_simple_poll_free(mc.simple_poll);
1510
if(gnutls_initialized){
1511
gnutls_certificate_free_credentials(mc.cred);
1512
gnutls_global_deinit();
1513
gnutls_dh_params_deinit(mc.dh_params);
1516
if(gpgme_initialized){
1517
gpgme_release(mc.ctx);
1520
/* Take down the network interface */
1521
if(take_down_interface){
1522
/* Re-raise priviliges */
1529
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1531
perror("ioctl SIOCGIFFLAGS");
1532
} else if(network.ifr_flags & IFF_UP) {
1533
network.ifr_flags &= ~IFF_UP; /* clear flag */
1534
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1536
perror("ioctl SIOCSIFFLAGS");
1539
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1543
/* Lower privileges permanently */
1552
/* Removes the temp directory used by GPGME */
1553
if(tempdir_created){
1555
struct dirent *direntry;
1556
d = opendir(tempdir);
1558
if(errno != ENOENT){
1563
direntry = readdir(d);
1564
if(direntry == NULL){
1567
/* Skip "." and ".." */
1568
if(direntry->d_name[0] == '.'
1569
and (direntry->d_name[1] == '\0'
1570
or (direntry->d_name[1] == '.'
1571
and direntry->d_name[2] == '\0'))){
1574
char *fullname = NULL;
1575
ret = asprintf(&fullname, "%s/%s", tempdir,
1581
ret = remove(fullname);
1583
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1590
ret = rmdir(tempdir);
1591
if(ret == -1 and errno != ENOENT){
1597
sigemptyset(&old_sigterm_action.sa_mask);
1598
old_sigterm_action.sa_handler = SIG_DFL;
1599
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1600
&old_sigterm_action,
1603
perror("sigaction");
1606
ret = raise(signal_received);
1607
} while(ret != 0 and errno == EINTR);
1612
TEMP_FAILURE_RETRY(pause());