1
/* -*- coding: utf-8 -*- */
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* Mandos-client - get and decrypt data from a Mandos server
5
* This program is partly derived from an example program for an Avahi
6
* service browser, downloaded from
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* <http://avahi.org/browser/examples/core-browse-services.c>. This
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* includes the following functions: "resolve_callback",
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* "browse_callback", and parts of "main".
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* Copyright © 2008,2009 Teddy Hogeborn
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* Copyright © 2008,2009 Björn Påhlsson
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* This program is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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* Contact the authors at <mandos@fukt.bsnet.se>.
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/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
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#ifndef _FILE_OFFSET_BITS
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#define _FILE_OFFSET_BITS 64
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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
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#include <stdio.h> /* fprintf(), stderr, fwrite(),
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stdout, ferror(), remove() */
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#include <stdint.h> /* uint16_t, uint32_t */
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#include <stddef.h> /* NULL, size_t, ssize_t */
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#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
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srand(), strtof(), abort() */
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#include <stdbool.h> /* bool, false, true */
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#include <string.h> /* memset(), strcmp(), strlen(),
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strerror(), asprintf(), strcpy() */
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#include <sys/ioctl.h> /* ioctl */
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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
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sockaddr_in6, PF_INET6,
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SOCK_STREAM, uid_t, gid_t, open(),
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#include <sys/stat.h> /* open() */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
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inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
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#include <assert.h> /* assert() */
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#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
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#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,
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INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
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getuid(), getgid(), seteuid(),
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#include <arpa/inet.h> /* inet_pton(), htons */
77
#include <iso646.h> /* not, or, and */
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#include <argp.h> /* struct argp_option, error_t, struct
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argp_state, struct argp,
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argp_parse(), ARGP_KEY_ARG,
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ARGP_KEY_END, ARGP_ERR_UNKNOWN */
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#include <signal.h> /* sigemptyset(), sigaddset(),
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sigaction(), SIGTERM, sig_atomic_t,
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#include <sysexits.h> /* EX_OSERR, EX_USAGE */
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#include <sys/klog.h> /* klogctl() */
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#endif /* __linux__ */
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/* All Avahi types, constants and functions
95
#include <avahi-core/core.h>
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#include <avahi-core/lookup.h>
97
#include <avahi-core/log.h>
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#include <avahi-common/simple-watch.h>
99
#include <avahi-common/malloc.h>
100
#include <avahi-common/error.h>
103
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
106
init_gnutls_session(),
108
#include <gnutls/openpgp.h>
109
/* gnutls_certificate_set_openpgp_key_file(),
110
GNUTLS_OPENPGP_FMT_BASE64 */
113
#include <gpgme.h> /* All GPGME types, constants and
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GPGME_PROTOCOL_OpenPGP,
119
#define BUFFER_SIZE 256
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#define PATHDIR "/conf/conf.d/mandos"
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#define SECKEY "seckey.txt"
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#define PUBKEY "pubkey.txt"
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static const char mandos_protocol_version[] = "1";
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const char *argp_program_version = "mandos-client " VERSION;
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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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/* Used for passing in values through the Avahi callback functions */
132
AvahiSimplePoll *simple_poll;
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gnutls_certificate_credentials_t cred;
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unsigned int dh_bits;
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gnutls_dh_params_t dh_params;
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const char *priority;
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/* global context so signal handler can reach it*/
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mandos_context mc = { .simple_poll = NULL, .server = NULL,
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.dh_bits = 1024, .priority = "SECURE256"
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":!CTYPE-X.509:+CTYPE-OPENPGP" };
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sig_atomic_t quit_now = 0;
147
int signal_received = 0;
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* Make additional room in "buffer" for at least BUFFER_SIZE more
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* bytes. "buffer_capacity" is how much is currently allocated,
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* "buffer_length" is how much is already used.
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size_t incbuffer(char **buffer, size_t buffer_length,
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size_t buffer_capacity){
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if(buffer_length + BUFFER_SIZE > buffer_capacity){
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*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
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buffer_capacity += BUFFER_SIZE;
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return buffer_capacity;
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static bool init_gpgme(const char *seckey,
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const char *pubkey, const char *tempdir){
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gpgme_engine_info_t engine_info;
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* Helper function to insert pub and seckey to the engine keyring.
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bool import_key(const char *filename){
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gpgme_data_t pgp_data;
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fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
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rc = gpgme_data_new_from_fd(&pgp_data, fd);
190
if(rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
196
rc = gpgme_op_import(mc.ctx, pgp_data);
197
if(rc != GPG_ERR_NO_ERROR){
198
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
199
gpgme_strsource(rc), gpgme_strerror(rc));
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ret = (int)TEMP_FAILURE_RETRY(close(fd));
207
gpgme_data_release(pgp_data);
212
fprintf(stderr, "Initializing GPGME\n");
216
gpgme_check_version(NULL);
217
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
218
if(rc != GPG_ERR_NO_ERROR){
219
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
224
/* Set GPGME home directory for the OpenPGP engine only */
225
rc = gpgme_get_engine_info(&engine_info);
226
if(rc != GPG_ERR_NO_ERROR){
227
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
231
while(engine_info != NULL){
232
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
233
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
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engine_info->file_name, tempdir);
237
engine_info = engine_info->next;
239
if(engine_info == NULL){
240
fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);
244
/* Create new GPGME "context" */
245
rc = gpgme_new(&(mc.ctx));
246
if(rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_new: %s: %s\n",
248
gpgme_strsource(rc), gpgme_strerror(rc));
252
if(not import_key(pubkey) or not import_key(seckey)){
260
* Decrypt OpenPGP data.
261
* Returns -1 on error
263
static ssize_t pgp_packet_decrypt(const char *cryptotext,
266
gpgme_data_t dh_crypto, dh_plain;
269
size_t plaintext_capacity = 0;
270
ssize_t plaintext_length = 0;
273
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
276
/* Create new GPGME data buffer from memory cryptotext */
277
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
279
if(rc != GPG_ERR_NO_ERROR){
280
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
281
gpgme_strsource(rc), gpgme_strerror(rc));
285
/* Create new empty GPGME data buffer for the plaintext */
286
rc = gpgme_data_new(&dh_plain);
287
if(rc != GPG_ERR_NO_ERROR){
288
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
289
gpgme_strsource(rc), gpgme_strerror(rc));
290
gpgme_data_release(dh_crypto);
294
/* Decrypt data from the cryptotext data buffer to the plaintext
296
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
297
if(rc != GPG_ERR_NO_ERROR){
298
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
299
gpgme_strsource(rc), gpgme_strerror(rc));
300
plaintext_length = -1;
302
gpgme_decrypt_result_t result;
303
result = gpgme_op_decrypt_result(mc.ctx);
305
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
307
fprintf(stderr, "Unsupported algorithm: %s\n",
308
result->unsupported_algorithm);
309
fprintf(stderr, "Wrong key usage: %u\n",
310
result->wrong_key_usage);
311
if(result->file_name != NULL){
312
fprintf(stderr, "File name: %s\n", result->file_name);
314
gpgme_recipient_t recipient;
315
recipient = result->recipients;
316
while(recipient != NULL){
317
fprintf(stderr, "Public key algorithm: %s\n",
318
gpgme_pubkey_algo_name(recipient->pubkey_algo));
319
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
320
fprintf(stderr, "Secret key available: %s\n",
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recipient->status == GPG_ERR_NO_SECKEY
323
recipient = recipient->next;
331
fprintf(stderr, "Decryption of OpenPGP data succeeded\n");
334
/* Seek back to the beginning of the GPGME plaintext data buffer */
335
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
336
perror("gpgme_data_seek");
337
plaintext_length = -1;
343
plaintext_capacity = incbuffer(plaintext,
344
(size_t)plaintext_length,
346
if(plaintext_capacity == 0){
348
plaintext_length = -1;
352
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
354
/* Print the data, if any */
360
perror("gpgme_data_read");
361
plaintext_length = -1;
364
plaintext_length += ret;
368
fprintf(stderr, "Decrypted password is: ");
369
for(ssize_t i = 0; i < plaintext_length; i++){
370
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
372
fprintf(stderr, "\n");
377
/* Delete the GPGME cryptotext data buffer */
378
gpgme_data_release(dh_crypto);
380
/* Delete the GPGME plaintext data buffer */
381
gpgme_data_release(dh_plain);
382
return plaintext_length;
385
static const char * safer_gnutls_strerror(int value){
386
const char *ret = gnutls_strerror(value); /* Spurious warning from
387
-Wunreachable-code */
393
/* GnuTLS log function callback */
394
static void debuggnutls(__attribute__((unused)) int level,
396
fprintf(stderr, "GnuTLS: %s", string);
399
static int init_gnutls_global(const char *pubkeyfilename,
400
const char *seckeyfilename){
404
fprintf(stderr, "Initializing GnuTLS\n");
407
ret = gnutls_global_init();
408
if(ret != GNUTLS_E_SUCCESS){
409
fprintf(stderr, "GnuTLS global_init: %s\n",
410
safer_gnutls_strerror(ret));
415
/* "Use a log level over 10 to enable all debugging options."
418
gnutls_global_set_log_level(11);
419
gnutls_global_set_log_function(debuggnutls);
422
/* OpenPGP credentials */
423
gnutls_certificate_allocate_credentials(&mc.cred);
424
if(ret != GNUTLS_E_SUCCESS){
425
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
429
safer_gnutls_strerror(ret));
430
gnutls_global_deinit();
435
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
436
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
440
ret = gnutls_certificate_set_openpgp_key_file
441
(mc.cred, pubkeyfilename, seckeyfilename,
442
GNUTLS_OPENPGP_FMT_BASE64);
443
if(ret != GNUTLS_E_SUCCESS){
445
"Error[%d] while reading the OpenPGP key pair ('%s',"
446
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
447
fprintf(stderr, "The GnuTLS error is: %s\n",
448
safer_gnutls_strerror(ret));
452
/* GnuTLS server initialization */
453
ret = gnutls_dh_params_init(&mc.dh_params);
454
if(ret != GNUTLS_E_SUCCESS){
455
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
456
" %s\n", safer_gnutls_strerror(ret));
459
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
460
if(ret != GNUTLS_E_SUCCESS){
461
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
462
safer_gnutls_strerror(ret));
466
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
472
gnutls_certificate_free_credentials(mc.cred);
473
gnutls_global_deinit();
474
gnutls_dh_params_deinit(mc.dh_params);
478
static int init_gnutls_session(gnutls_session_t *session){
480
/* GnuTLS session creation */
482
ret = gnutls_init(session, GNUTLS_SERVER);
486
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
487
if(ret != GNUTLS_E_SUCCESS){
488
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
489
safer_gnutls_strerror(ret));
495
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
497
gnutls_deinit(*session);
500
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
501
if(ret != GNUTLS_E_SUCCESS){
502
fprintf(stderr, "Syntax error at: %s\n", err);
503
fprintf(stderr, "GnuTLS error: %s\n",
504
safer_gnutls_strerror(ret));
505
gnutls_deinit(*session);
511
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
514
gnutls_deinit(*session);
517
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
518
if(ret != GNUTLS_E_SUCCESS){
519
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
520
safer_gnutls_strerror(ret));
521
gnutls_deinit(*session);
525
/* ignore client certificate if any. */
526
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
528
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
533
/* Avahi log function callback */
534
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
535
__attribute__((unused)) const char *txt){}
537
/* Called when a Mandos server is found */
538
static int start_mandos_communication(const char *ip, uint16_t port,
539
AvahiIfIndex if_index,
541
int ret, tcp_sd = -1;
544
struct sockaddr_in in;
545
struct sockaddr_in6 in6;
548
char *decrypted_buffer = NULL;
549
size_t buffer_length = 0;
550
size_t buffer_capacity = 0;
553
gnutls_session_t session;
554
int pf; /* Protocol family */
568
fprintf(stderr, "Bad address family: %d\n", af);
572
ret = init_gnutls_session(&session);
578
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
582
tcp_sd = socket(pf, SOCK_STREAM, 0);
592
memset(&to, 0, sizeof(to));
594
to.in6.sin6_family = (sa_family_t)af;
595
ret = inet_pton(af, ip, &to.in6.sin6_addr);
597
to.in.sin_family = (sa_family_t)af;
598
ret = inet_pton(af, ip, &to.in.sin_addr);
605
fprintf(stderr, "Bad address: %s\n", ip);
609
to.in6.sin6_port = htons(port); /* Spurious warnings from
611
-Wunreachable-code */
613
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
614
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
616
if(if_index == AVAHI_IF_UNSPEC){
617
fprintf(stderr, "An IPv6 link-local address is incomplete"
618
" without a network interface\n");
621
/* Set the network interface number as scope */
622
to.in6.sin6_scope_id = (uint32_t)if_index;
625
to.in.sin_port = htons(port); /* Spurious warnings from
627
-Wunreachable-code */
635
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
636
char interface[IF_NAMESIZE];
637
if(if_indextoname((unsigned int)if_index, interface) == NULL){
638
perror("if_indextoname");
640
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
641
ip, interface, port);
644
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
647
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
648
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
651
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
654
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
660
if(strcmp(addrstr, ip) != 0){
661
fprintf(stderr, "Canonical address form: %s\n", addrstr);
671
ret = connect(tcp_sd, &to.in6, sizeof(to));
673
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
684
const char *out = mandos_protocol_version;
687
size_t out_size = strlen(out);
688
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
689
out_size - written));
694
written += (size_t)ret;
695
if(written < out_size){
698
if(out == mandos_protocol_version){
712
fprintf(stderr, "Establishing TLS session with %s\n", ip);
719
gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);
726
ret = gnutls_handshake(session);
730
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
732
if(ret != GNUTLS_E_SUCCESS){
734
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
740
/* Read OpenPGP packet that contains the wanted password */
743
fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",
753
buffer_capacity = incbuffer(&buffer, buffer_length,
755
if(buffer_capacity == 0){
764
sret = gnutls_record_recv(session, buffer+buffer_length,
771
case GNUTLS_E_INTERRUPTED:
774
case GNUTLS_E_REHANDSHAKE:
776
ret = gnutls_handshake(session);
781
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
783
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
789
fprintf(stderr, "Unknown error while reading data from"
790
" encrypted session with Mandos server\n");
791
gnutls_bye(session, GNUTLS_SHUT_RDWR);
795
buffer_length += (size_t) sret;
800
fprintf(stderr, "Closing TLS session\n");
808
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
812
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
814
if(buffer_length > 0){
815
ssize_t decrypted_buffer_size;
816
decrypted_buffer_size = pgp_packet_decrypt(buffer,
819
if(decrypted_buffer_size >= 0){
822
while(written < (size_t) decrypted_buffer_size){
827
ret = (int)fwrite(decrypted_buffer + written, 1,
828
(size_t)decrypted_buffer_size - written,
830
if(ret == 0 and ferror(stdout)){
832
fprintf(stderr, "Error writing encrypted data: %s\n",
837
written += (size_t)ret;
843
/* Shutdown procedure */
846
free(decrypted_buffer);
849
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
854
gnutls_deinit(session);
861
static void resolve_callback(AvahiSServiceResolver *r,
862
AvahiIfIndex interface,
864
AvahiResolverEvent event,
868
const char *host_name,
869
const AvahiAddress *address,
871
AVAHI_GCC_UNUSED AvahiStringList *txt,
872
AVAHI_GCC_UNUSED AvahiLookupResultFlags
874
AVAHI_GCC_UNUSED void* userdata){
877
/* Called whenever a service has been resolved successfully or
886
case AVAHI_RESOLVER_FAILURE:
887
fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
888
" of type '%s' in domain '%s': %s\n", name, type, domain,
889
avahi_strerror(avahi_server_errno(mc.server)));
892
case AVAHI_RESOLVER_FOUND:
894
char ip[AVAHI_ADDRESS_STR_MAX];
895
avahi_address_snprint(ip, sizeof(ip), address);
897
fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"
898
PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
899
ip, (intmax_t)interface, port);
901
int ret = start_mandos_communication(ip, port, interface,
902
avahi_proto_to_af(proto));
904
avahi_simple_poll_quit(mc.simple_poll);
908
avahi_s_service_resolver_free(r);
911
static void browse_callback(AvahiSServiceBrowser *b,
912
AvahiIfIndex interface,
913
AvahiProtocol protocol,
914
AvahiBrowserEvent event,
918
AVAHI_GCC_UNUSED AvahiLookupResultFlags
920
AVAHI_GCC_UNUSED void* userdata){
923
/* Called whenever a new services becomes available on the LAN or
924
is removed from the LAN */
932
case AVAHI_BROWSER_FAILURE:
934
fprintf(stderr, "(Avahi browser) %s\n",
935
avahi_strerror(avahi_server_errno(mc.server)));
936
avahi_simple_poll_quit(mc.simple_poll);
939
case AVAHI_BROWSER_NEW:
940
/* We ignore the returned Avahi resolver object. In the callback
941
function we free it. If the Avahi server is terminated before
942
the callback function is called the Avahi server will free the
945
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
946
name, type, domain, protocol, 0,
947
resolve_callback, NULL) == NULL)
948
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
949
name, avahi_strerror(avahi_server_errno(mc.server)));
952
case AVAHI_BROWSER_REMOVE:
955
case AVAHI_BROWSER_ALL_FOR_NOW:
956
case AVAHI_BROWSER_CACHE_EXHAUSTED:
958
fprintf(stderr, "No Mandos server found, still searching...\n");
964
/* stop main loop after sigterm has been called */
965
static void handle_sigterm(int sig){
970
signal_received = sig;
971
int old_errno = errno;
972
if(mc.simple_poll != NULL){
973
avahi_simple_poll_quit(mc.simple_poll);
978
int main(int argc, char *argv[]){
979
AvahiSServiceBrowser *sb = NULL;
984
int exitcode = EXIT_SUCCESS;
985
const char *interface = "eth0";
986
struct ifreq network;
988
bool take_down_interface = false;
991
char *connect_to = NULL;
992
char tempdir[] = "/tmp/mandosXXXXXX";
993
bool tempdir_created = false;
994
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
995
const char *seckey = PATHDIR "/" SECKEY;
996
const char *pubkey = PATHDIR "/" PUBKEY;
998
bool gnutls_initialized = false;
999
bool gpgme_initialized = false;
1002
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1003
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1008
/* Lower any group privileges we might have, just to be safe */
1015
/* Lower user privileges (temporarily) */
1027
struct argp_option options[] = {
1028
{ .name = "debug", .key = 128,
1029
.doc = "Debug mode", .group = 3 },
1030
{ .name = "connect", .key = 'c',
1031
.arg = "ADDRESS:PORT",
1032
.doc = "Connect directly to a specific Mandos server",
1034
{ .name = "interface", .key = 'i',
1036
.doc = "Network interface that will be used to search for"
1039
{ .name = "seckey", .key = 's',
1041
.doc = "OpenPGP secret key file base name",
1043
{ .name = "pubkey", .key = 'p',
1045
.doc = "OpenPGP public key file base name",
1047
{ .name = "dh-bits", .key = 129,
1049
.doc = "Bit length of the prime number used in the"
1050
" Diffie-Hellman key exchange",
1052
{ .name = "priority", .key = 130,
1054
.doc = "GnuTLS priority string for the TLS handshake",
1056
{ .name = "delay", .key = 131,
1058
.doc = "Maximum delay to wait for interface startup",
1061
* These reproduce what we would get without ARGP_NO_HELP
1063
{ .name = "help", .key = '?',
1064
.doc = "Give this help list", .group = -1 },
1065
{ .name = "usage", .key = -3,
1066
.doc = "Give a short usage message", .group = -1 },
1067
{ .name = "version", .key = 'V',
1068
.doc = "Print program version", .group = -1 },
1072
error_t parse_opt(int key, char *arg,
1073
struct argp_state *state){
1076
case 128: /* --debug */
1079
case 'c': /* --connect */
1082
case 'i': /* --interface */
1085
case 's': /* --seckey */
1088
case 'p': /* --pubkey */
1091
case 129: /* --dh-bits */
1093
tmpmax = strtoimax(arg, &tmp, 10);
1094
if(errno != 0 or tmp == arg or *tmp != '\0'
1095
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1096
argp_error(state, "Bad number of DH bits");
1098
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1100
case 130: /* --priority */
1103
case 131: /* --delay */
1105
delay = strtof(arg, &tmp);
1106
if(errno != 0 or tmp == arg or *tmp != '\0'){
1107
argp_error(state, "Bad delay");
1111
* These reproduce what we would get without ARGP_NO_HELP
1113
case '?': /* --help */
1114
argp_state_help(state, state->out_stream,
1115
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1116
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1117
case -3: /* --usage */
1118
argp_state_help(state, state->out_stream,
1119
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1120
case 'V': /* --version */
1121
fprintf(state->out_stream, "%s\n", argp_program_version);
1122
exit(argp_err_exit_status);
1125
return ARGP_ERR_UNKNOWN;
1130
struct argp argp = { .options = options, .parser = parse_opt,
1132
.doc = "Mandos client -- Get and decrypt"
1133
" passwords from a Mandos server" };
1134
ret = argp_parse(&argp, argc, argv,
1135
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1142
perror("argp_parse");
1143
exitcode = EX_OSERR;
1146
exitcode = EX_USAGE;
1152
avahi_set_log_function(empty_log);
1155
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1156
from the signal handler */
1157
/* Initialize the pseudo-RNG for Avahi */
1158
srand((unsigned int) time(NULL));
1159
mc.simple_poll = avahi_simple_poll_new();
1160
if(mc.simple_poll == NULL){
1161
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1162
exitcode = EXIT_FAILURE;
1166
sigemptyset(&sigterm_action.sa_mask);
1167
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1169
perror("sigaddset");
1170
exitcode = EXIT_FAILURE;
1173
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1175
perror("sigaddset");
1176
exitcode = EXIT_FAILURE;
1179
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1181
perror("sigaddset");
1182
exitcode = EXIT_FAILURE;
1185
/* Need to check if the handler is SIG_IGN before handling:
1186
| [[info:libc:Initial Signal Actions]] |
1187
| [[info:libc:Basic Signal Handling]] |
1189
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1191
perror("sigaction");
1192
return EXIT_FAILURE;
1194
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
ret = sigaction(SIGINT, &sigterm_action, NULL);
1197
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
1202
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1204
perror("sigaction");
1205
return EXIT_FAILURE;
1207
if(old_sigterm_action.sa_handler != SIG_IGN){
1208
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1210
perror("sigaction");
1211
exitcode = EXIT_FAILURE;
1215
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1217
perror("sigaction");
1218
return EXIT_FAILURE;
1220
if(old_sigterm_action.sa_handler != SIG_IGN){
1221
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1223
perror("sigaction");
1224
exitcode = EXIT_FAILURE;
1229
/* If the interface is down, bring it up */
1230
if(interface[0] != '\0'){
1231
if_index = (AvahiIfIndex) if_nametoindex(interface);
1233
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1234
exitcode = EXIT_FAILURE;
1242
/* Re-raise priviliges */
1250
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1251
messages about the network interface to mess up the prompt */
1252
ret = klogctl(8, NULL, 5);
1253
bool restore_loglevel = true;
1255
restore_loglevel = false;
1258
#endif /* __linux__ */
1260
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1263
exitcode = EXIT_FAILURE;
1265
if(restore_loglevel){
1266
ret = klogctl(7, NULL, 0);
1271
#endif /* __linux__ */
1272
/* Lower privileges */
1280
strcpy(network.ifr_name, interface);
1281
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1283
perror("ioctl SIOCGIFFLAGS");
1285
if(restore_loglevel){
1286
ret = klogctl(7, NULL, 0);
1291
#endif /* __linux__ */
1292
exitcode = EXIT_FAILURE;
1293
/* Lower privileges */
1301
if((network.ifr_flags & IFF_UP) == 0){
1302
network.ifr_flags |= IFF_UP;
1303
take_down_interface = true;
1304
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1306
take_down_interface = false;
1307
perror("ioctl SIOCSIFFLAGS");
1308
exitcode = EXIT_FAILURE;
1310
if(restore_loglevel){
1311
ret = klogctl(7, NULL, 0);
1316
#endif /* __linux__ */
1317
/* Lower privileges */
1326
/* sleep checking until interface is running */
1327
for(int i=0; i < delay * 4; i++){
1328
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1330
perror("ioctl SIOCGIFFLAGS");
1331
} else if(network.ifr_flags & IFF_RUNNING){
1334
struct timespec sleeptime = { .tv_nsec = 250000000 };
1335
ret = nanosleep(&sleeptime, NULL);
1336
if(ret == -1 and errno != EINTR){
1337
perror("nanosleep");
1340
if(not take_down_interface){
1341
/* We won't need the socket anymore */
1342
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1348
if(restore_loglevel){
1349
/* Restores kernel loglevel to default */
1350
ret = klogctl(7, NULL, 0);
1355
#endif /* __linux__ */
1356
/* Lower privileges */
1358
if(take_down_interface){
1359
/* Lower privileges */
1365
/* Lower privileges permanently */
1377
ret = init_gnutls_global(pubkey, seckey);
1379
fprintf(stderr, "init_gnutls_global failed\n");
1380
exitcode = EXIT_FAILURE;
1383
gnutls_initialized = true;
1390
tempdir_created = true;
1391
if(mkdtemp(tempdir) == NULL){
1392
tempdir_created = false;
1401
if(not init_gpgme(pubkey, seckey, tempdir)){
1402
fprintf(stderr, "init_gpgme failed\n");
1403
exitcode = EXIT_FAILURE;
1406
gpgme_initialized = true;
1413
if(connect_to != NULL){
1414
/* Connect directly, do not use Zeroconf */
1415
/* (Mainly meant for debugging) */
1416
char *address = strrchr(connect_to, ':');
1417
if(address == NULL){
1418
fprintf(stderr, "No colon in address\n");
1419
exitcode = EXIT_FAILURE;
1429
tmpmax = strtoimax(address+1, &tmp, 10);
1430
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1431
or tmpmax != (uint16_t)tmpmax){
1432
fprintf(stderr, "Bad port number\n");
1433
exitcode = EXIT_FAILURE;
1441
port = (uint16_t)tmpmax;
1443
address = connect_to;
1444
/* Colon in address indicates IPv6 */
1446
if(strchr(address, ':') != NULL){
1456
ret = start_mandos_communication(address, port, if_index, af);
1458
exitcode = EXIT_FAILURE;
1460
exitcode = EXIT_SUCCESS;
1470
AvahiServerConfig config;
1471
/* Do not publish any local Zeroconf records */
1472
avahi_server_config_init(&config);
1473
config.publish_hinfo = 0;
1474
config.publish_addresses = 0;
1475
config.publish_workstation = 0;
1476
config.publish_domain = 0;
1478
/* Allocate a new server */
1479
mc.server = avahi_server_new(avahi_simple_poll_get
1480
(mc.simple_poll), &config, NULL,
1483
/* Free the Avahi configuration data */
1484
avahi_server_config_free(&config);
1487
/* Check if creating the Avahi server object succeeded */
1488
if(mc.server == NULL){
1489
fprintf(stderr, "Failed to create Avahi server: %s\n",
1490
avahi_strerror(error));
1491
exitcode = EXIT_FAILURE;
1499
/* Create the Avahi service browser */
1500
sb = avahi_s_service_browser_new(mc.server, if_index,
1501
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1502
NULL, 0, browse_callback, NULL);
1504
fprintf(stderr, "Failed to create service browser: %s\n",
1505
avahi_strerror(avahi_server_errno(mc.server)));
1506
exitcode = EXIT_FAILURE;
1514
/* Run the main loop */
1517
fprintf(stderr, "Starting Avahi loop search\n");
1520
avahi_simple_poll_loop(mc.simple_poll);
1525
fprintf(stderr, "%s exiting\n", argv[0]);
1528
/* Cleanup things */
1530
avahi_s_service_browser_free(sb);
1532
if(mc.server != NULL)
1533
avahi_server_free(mc.server);
1535
if(mc.simple_poll != NULL)
1536
avahi_simple_poll_free(mc.simple_poll);
1538
if(gnutls_initialized){
1539
gnutls_certificate_free_credentials(mc.cred);
1540
gnutls_global_deinit();
1541
gnutls_dh_params_deinit(mc.dh_params);
1544
if(gpgme_initialized){
1545
gpgme_release(mc.ctx);
1548
/* Take down the network interface */
1549
if(take_down_interface){
1550
/* Re-raise priviliges */
1557
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1559
perror("ioctl SIOCGIFFLAGS");
1560
} else if(network.ifr_flags & IFF_UP) {
1561
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1562
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1564
perror("ioctl SIOCSIFFLAGS");
1567
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1571
/* Lower privileges permanently */
1580
/* Removes the temp directory used by GPGME */
1581
if(tempdir_created){
1583
struct dirent *direntry;
1584
d = opendir(tempdir);
1586
if(errno != ENOENT){
1591
direntry = readdir(d);
1592
if(direntry == NULL){
1595
/* Skip "." and ".." */
1596
if(direntry->d_name[0] == '.'
1597
and (direntry->d_name[1] == '\0'
1598
or (direntry->d_name[1] == '.'
1599
and direntry->d_name[2] == '\0'))){
1602
char *fullname = NULL;
1603
ret = asprintf(&fullname, "%s/%s", tempdir,
1609
ret = remove(fullname);
1611
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1618
ret = rmdir(tempdir);
1619
if(ret == -1 and errno != ENOENT){
1625
sigemptyset(&old_sigterm_action.sa_mask);
1626
old_sigterm_action.sa_handler = SIG_DFL;
1627
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
1628
&old_sigterm_action,
1631
perror("sigaction");
1634
ret = raise(signal_received);
1635
} while(ret != 0 and errno == EINTR);
1640
TEMP_FAILURE_RETRY(pause());