32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
 
33
 
#ifndef _LARGEFILE_SOURCE
 
34
33
#define _LARGEFILE_SOURCE
 
36
 
#ifndef _FILE_OFFSET_BITS
 
37
34
#define _FILE_OFFSET_BITS 64
 
40
36
#define _GNU_SOURCE             /* TEMP_FAILURE_RETRY(), asprintf() */
 
42
38
#include <stdio.h>              /* fprintf(), stderr, fwrite(),
 
43
 
                                   stdout, ferror(), remove() */
 
 
39
                                   stdout, ferror(), sscanf(),
 
44
41
#include <stdint.h>             /* uint16_t, uint32_t */
 
45
42
#include <stddef.h>             /* NULL, size_t, ssize_t */
 
46
43
#include <stdlib.h>             /* free(), EXIT_SUCCESS, EXIT_FAILURE,
 
48
45
#include <stdbool.h>            /* bool, false, true */
 
49
46
#include <string.h>             /* memset(), strcmp(), strlen(),
 
50
47
                                   strerror(), asprintf(), strcpy() */
 
 
59
56
#include <fcntl.h>              /* open() */
 
60
57
#include <dirent.h>             /* opendir(), struct dirent, readdir()
 
62
 
#include <inttypes.h>           /* PRIu16, PRIdMAX, intmax_t,
 
 
59
#include <inttypes.h>           /* PRIu16, intmax_t, SCNdMAX */
 
64
60
#include <assert.h>             /* assert() */
 
65
61
#include <errno.h>              /* perror(), errno */
 
66
62
#include <time.h>               /* nanosleep(), time() */
 
 
79
75
                                   argp_state, struct argp,
 
80
76
                                   argp_parse(), ARGP_KEY_ARG,
 
81
77
                                   ARGP_KEY_END, ARGP_ERR_UNKNOWN */
 
82
 
#include <signal.h>             /* sigemptyset(), sigaddset(),
 
83
 
                                   sigaction(), SIGTERM, sigaction,
 
87
79
#include <sys/klog.h>           /* klogctl() */
 
88
 
#endif  /* __linux__ */
 
91
83
/* All Avahi types, constants and functions
 
 
138
130
} mandos_context;
 
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" };
 
146
 
 * Make additional room in "buffer" for at least BUFFER_SIZE more
 
147
 
 * bytes. "buffer_capacity" is how much is currently allocated,
 
 
133
 * Make room in "buffer" for at least BUFFER_SIZE additional bytes.
 
 
134
 * "buffer_capacity" is how much is currently allocated,
 
148
135
 * "buffer_length" is how much is already used.
 
150
 
size_t incbuffer(char **buffer, size_t buffer_length,
 
 
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
 
151
138
                  size_t buffer_capacity){
 
152
139
  if(buffer_length + BUFFER_SIZE > buffer_capacity){
 
153
140
    *buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
 
 
163
150
 * Initialize GPGME.
 
165
 
static bool init_gpgme(const char *seckey,
 
 
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
 
166
153
                       const char *pubkey, const char *tempdir){
 
168
155
  gpgme_error_t rc;
 
 
192
 
    rc = gpgme_op_import(mc.ctx, pgp_data);
 
 
179
    rc = gpgme_op_import(mc->ctx, pgp_data);
 
193
180
    if(rc != GPG_ERR_NO_ERROR){
 
194
181
      fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
 
195
182
              gpgme_strsource(rc), gpgme_strerror(rc));
 
 
240
227
  /* Create new GPGME "context" */
 
241
 
  rc = gpgme_new(&(mc.ctx));
 
 
228
  rc = gpgme_new(&(mc->ctx));
 
242
229
  if(rc != GPG_ERR_NO_ERROR){
 
243
230
    fprintf(stderr, "bad gpgme_new: %s: %s\n",
 
244
231
            gpgme_strsource(rc), gpgme_strerror(rc));
 
 
256
243
 * Decrypt OpenPGP data.
 
257
244
 * Returns -1 on error
 
259
 
static ssize_t pgp_packet_decrypt(const char *cryptotext,
 
 
246
static ssize_t pgp_packet_decrypt(const mandos_context *mc,
 
 
247
                                  const char *cryptotext,
 
260
248
                                  size_t crypto_size,
 
261
249
                                  char **plaintext){
 
262
250
  gpgme_data_t dh_crypto, dh_plain;
 
 
290
278
  /* Decrypt data from the cryptotext data buffer to the plaintext
 
292
 
  rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
 
 
280
  rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
 
293
281
  if(rc != GPG_ERR_NO_ERROR){
 
294
282
    fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
 
295
283
            gpgme_strsource(rc), gpgme_strerror(rc));
 
296
284
    plaintext_length = -1;
 
298
286
      gpgme_decrypt_result_t result;
 
299
 
      result = gpgme_op_decrypt_result(mc.ctx);
 
 
287
      result = gpgme_op_decrypt_result(mc->ctx);
 
300
288
      if(result == NULL){
 
301
289
        fprintf(stderr, "gpgme_op_decrypt_result failed\n");
 
 
339
327
  *plaintext = NULL;
 
341
 
    plaintext_capacity = incbuffer(plaintext,
 
 
329
    plaintext_capacity = adjustbuffer(plaintext,
 
342
330
                                      (size_t)plaintext_length,
 
343
331
                                      plaintext_capacity);
 
344
332
    if(plaintext_capacity == 0){
 
 
333
        perror("adjustbuffer");
 
346
334
        plaintext_length = -1;
 
347
335
        goto decrypt_end;
 
 
394
382
  fprintf(stderr, "GnuTLS: %s", string);
 
397
 
static int init_gnutls_global(const char *pubkeyfilename,
 
 
385
static int init_gnutls_global(mandos_context *mc,
 
 
386
                              const char *pubkeyfilename,
 
398
387
                              const char *seckeyfilename){
 
 
420
409
  /* OpenPGP credentials */
 
421
 
  gnutls_certificate_allocate_credentials(&mc.cred);
 
 
410
  gnutls_certificate_allocate_credentials(&mc->cred);
 
422
411
  if(ret != GNUTLS_E_SUCCESS){
 
423
412
    fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
 
 
438
427
  ret = gnutls_certificate_set_openpgp_key_file
 
439
 
    (mc.cred, pubkeyfilename, seckeyfilename,
 
 
428
    (mc->cred, pubkeyfilename, seckeyfilename,
 
440
429
     GNUTLS_OPENPGP_FMT_BASE64);
 
441
430
  if(ret != GNUTLS_E_SUCCESS){
 
 
450
439
  /* GnuTLS server initialization */
 
451
 
  ret = gnutls_dh_params_init(&mc.dh_params);
 
 
440
  ret = gnutls_dh_params_init(&mc->dh_params);
 
452
441
  if(ret != GNUTLS_E_SUCCESS){
 
453
442
    fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
 
454
443
            " %s\n", safer_gnutls_strerror(ret));
 
457
 
  ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
 
 
446
  ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
 
458
447
  if(ret != GNUTLS_E_SUCCESS){
 
459
448
    fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
 
460
449
            safer_gnutls_strerror(ret));
 
464
 
  gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
 
 
453
  gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
 
470
 
  gnutls_certificate_free_credentials(mc.cred);
 
 
459
  gnutls_certificate_free_credentials(mc->cred);
 
471
460
  gnutls_global_deinit();
 
472
 
  gnutls_dh_params_deinit(mc.dh_params);
 
 
461
  gnutls_dh_params_deinit(mc->dh_params);
 
476
 
static int init_gnutls_session(gnutls_session_t *session){
 
 
465
static int init_gnutls_session(mandos_context *mc,
 
 
466
                               gnutls_session_t *session){
 
478
468
  /* GnuTLS session creation */
 
479
469
  ret = gnutls_init(session, GNUTLS_SERVER);
 
 
487
 
    ret = gnutls_priority_set_direct(*session, mc.priority, &err);
 
 
477
    ret = gnutls_priority_set_direct(*session, mc->priority, &err);
 
488
478
    if(ret != GNUTLS_E_SUCCESS){
 
489
479
      fprintf(stderr, "Syntax error at: %s\n", err);
 
490
480
      fprintf(stderr, "GnuTLS error: %s\n",
 
 
497
487
  ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
 
499
489
  if(ret != GNUTLS_E_SUCCESS){
 
500
490
    fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
 
501
491
            safer_gnutls_strerror(ret));
 
 
507
497
  gnutls_certificate_server_set_request(*session,
 
508
498
                                        GNUTLS_CERT_IGNORE);
 
510
 
  gnutls_dh_set_prime_bits(*session, mc.dh_bits);
 
 
500
  gnutls_dh_set_prime_bits(*session, mc->dh_bits);
 
 
519
509
/* Called when a Mandos server is found */
 
520
510
static int start_mandos_communication(const char *ip, uint16_t port,
 
521
511
                                      AvahiIfIndex if_index,
 
 
512
                                      mandos_context *mc, int af){
 
 
698
 
    buffer_capacity = incbuffer(&buffer, buffer_length,
 
 
688
    buffer_capacity = adjustbuffer(&buffer, buffer_length,
 
699
689
                                   buffer_capacity);
 
700
690
    if(buffer_capacity == 0){
 
 
691
      perror("adjustbuffer");
 
 
743
733
  gnutls_bye(session, GNUTLS_SHUT_RDWR);
 
745
735
  if(buffer_length > 0){
 
746
 
    decrypted_buffer_size = pgp_packet_decrypt(buffer,
 
 
736
    decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
 
748
738
                                               &decrypted_buffer);
 
749
739
    if(decrypted_buffer_size >= 0){
 
 
795
785
                             AVAHI_GCC_UNUSED AvahiStringList *txt,
 
796
786
                             AVAHI_GCC_UNUSED AvahiLookupResultFlags
 
798
 
                             AVAHI_GCC_UNUSED void* userdata){
 
 
789
  mandos_context *mc = userdata;
 
801
792
  /* Called whenever a service has been resolved successfully or
 
 
806
797
  case AVAHI_RESOLVER_FAILURE:
 
807
798
    fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
 
808
799
            " of type '%s' in domain '%s': %s\n", name, type, domain,
 
809
 
            avahi_strerror(avahi_server_errno(mc.server)));
 
 
800
            avahi_strerror(avahi_server_errno(mc->server)));
 
812
803
  case AVAHI_RESOLVER_FOUND:
 
 
818
809
                PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
 
819
810
                ip, (intmax_t)interface, port);
 
821
 
      int ret = start_mandos_communication(ip, port, interface,
 
 
812
      int ret = start_mandos_communication(ip, port, interface, mc,
 
822
813
                                           avahi_proto_to_af(proto));
 
824
 
        avahi_simple_poll_quit(mc.simple_poll);
 
 
815
        avahi_simple_poll_quit(mc->simple_poll);
 
 
848
840
  case AVAHI_BROWSER_FAILURE:
 
850
842
    fprintf(stderr, "(Avahi browser) %s\n",
 
851
 
            avahi_strerror(avahi_server_errno(mc.server)));
 
852
 
    avahi_simple_poll_quit(mc.simple_poll);
 
 
843
            avahi_strerror(avahi_server_errno(mc->server)));
 
 
844
    avahi_simple_poll_quit(mc->simple_poll);
 
855
847
  case AVAHI_BROWSER_NEW:
 
 
858
850
       the callback function is called the Avahi server will free the
 
859
851
       resolver for us. */
 
861
 
    if(avahi_s_service_resolver_new(mc.server, interface, protocol,
 
862
 
                                    name, type, domain, protocol, 0,
 
863
 
                                    resolve_callback, NULL) == NULL)
 
 
853
    if(!(avahi_s_service_resolver_new(mc->server, interface,
 
 
854
                                       protocol, name, type, domain,
 
 
855
                                       AVAHI_PROTO_INET6, 0,
 
 
856
                                       resolve_callback, mc)))
 
864
857
      fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
 
865
 
              name, avahi_strerror(avahi_server_errno(mc.server)));
 
 
858
              name, avahi_strerror(avahi_server_errno(mc->server)));
 
868
861
  case AVAHI_BROWSER_REMOVE:
 
 
880
 
sig_atomic_t quit_now = 0;
 
882
 
/* stop main loop after sigterm has been called */
 
883
 
static void handle_sigterm(__attribute__((unused)) int sig){
 
888
 
  int old_errno = errno;
 
889
 
  if(mc.simple_poll != NULL){
 
890
 
    avahi_simple_poll_quit(mc.simple_poll);
 
895
873
int main(int argc, char *argv[]){
 
896
874
  AvahiSServiceBrowser *sb = NULL;
 
901
879
  int exitcode = EXIT_SUCCESS;
 
902
880
  const char *interface = "eth0";
 
903
881
  struct ifreq network;
 
 
911
889
  const char *seckey = PATHDIR "/" SECKEY;
 
912
890
  const char *pubkey = PATHDIR "/" PUBKEY;
 
 
892
  mandos_context mc = { .simple_poll = NULL, .server = NULL,
 
 
893
                        .dh_bits = 1024, .priority = "SECURE256"
 
 
894
                        ":!CTYPE-X.509:+CTYPE-OPENPGP" };
 
914
895
  bool gnutls_initialized = false;
 
915
896
  bool gpgme_initialized = false;
 
918
 
  struct sigaction old_sigterm_action;
 
919
 
  struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
 
922
900
    struct argp_option options[] = {
 
 
976
954
      case 129:                 /* --dh-bits */
 
978
 
        tmpmax = strtoimax(arg, &tmp, 10);
 
979
 
        if(errno != 0 or tmp == arg or *tmp != '\0'
 
980
 
           or tmpmax != (typeof(mc.dh_bits))tmpmax){
 
 
955
        ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
 
 
956
        if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
 
 
957
           or arg[numchars] != '\0'){
 
981
958
          fprintf(stderr, "Bad number of DH bits\n");
 
982
959
          exit(EXIT_FAILURE);
 
 
987
964
        mc.priority = arg;
 
989
966
      case 131:                 /* --delay */
 
991
 
        delay = strtof(arg, &tmp);
 
992
 
        if(errno != 0 or tmp == arg or *tmp != '\0'){
 
 
967
        ret = sscanf(arg, "%lf%n", &delay, &numchars);
 
 
968
        if(ret < 1 or arg[numchars] != '\0'){
 
993
969
          fprintf(stderr, "Bad delay\n");
 
994
970
          exit(EXIT_FAILURE);
 
 
1020
 
    avahi_set_log_function(empty_log);
 
1023
 
  /* Initialize Avahi early so avahi_simple_poll_quit() can be called
 
1024
 
     from the signal handler */
 
1025
 
  /* Initialize the pseudo-RNG for Avahi */
 
1026
 
  srand((unsigned int) time(NULL));
 
1027
 
  mc.simple_poll = avahi_simple_poll_new();
 
1028
 
  if(mc.simple_poll == NULL){
 
1029
 
    fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
 
1030
 
    exitcode = EXIT_FAILURE;
 
1034
 
  sigemptyset(&sigterm_action.sa_mask);
 
1035
 
  ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
 
1037
 
    perror("sigaddset");
 
1038
 
    exitcode = EXIT_FAILURE;
 
1041
 
  ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
 
1043
 
    perror("sigaddset");
 
1044
 
    exitcode = EXIT_FAILURE;
 
1047
 
  ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
 
1049
 
    perror("sigaddset");
 
1050
 
    exitcode = EXIT_FAILURE;
 
1053
 
  ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
 
1055
 
    perror("sigaction");
 
1056
 
    exitcode = EXIT_FAILURE;
 
1060
995
  /* If the interface is down, bring it up */
 
1061
996
  if(interface[0] != '\0'){
 
1062
997
#ifdef __linux__
 
 
1159
1094
    perror("setuid");
 
1162
 
  ret = init_gnutls_global(pubkey, seckey);
 
 
1097
  ret = init_gnutls_global(&mc, pubkey, seckey);
 
1164
1099
    fprintf(stderr, "init_gnutls_global failed\n");
 
1165
1100
    exitcode = EXIT_FAILURE;
 
 
1175
1110
  tempdir_created = true;
 
1177
 
  if(not init_gpgme(pubkey, seckey, tempdir)){
 
 
1112
  if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
 
1178
1113
    fprintf(stderr, "init_gpgme failed\n");
 
1179
1114
    exitcode = EXIT_FAILURE;
 
 
1205
 
    tmpmax = strtoimax(address+1, &tmp, 10);
 
1206
 
    if(errno != 0 or tmp == address+1 or *tmp != '\0'
 
1207
 
       or tmpmax != (uint16_t)tmpmax){
 
 
1139
    ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
 
 
1140
    if(ret < 1 or tmpmax != (uint16_t)tmpmax
 
 
1141
       or address[numchars+1] != '\0'){
 
1208
1142
      fprintf(stderr, "Bad port number\n");
 
1209
1143
      exitcode = EXIT_FAILURE;
 
 
1222
 
    ret = start_mandos_communication(address, port, if_index, af);
 
 
1156
    ret = start_mandos_communication(address, port, if_index, &mc,
 
1224
1159
      exitcode = EXIT_FAILURE;
 
 
 
1167
    avahi_set_log_function(empty_log);
 
 
1170
  /* Initialize the pseudo-RNG for Avahi */
 
 
1171
  srand((unsigned int) time(NULL));
 
 
1173
  /* Allocate main Avahi loop object */
 
 
1174
  mc.simple_poll = avahi_simple_poll_new();
 
 
1175
  if(mc.simple_poll == NULL){
 
 
1176
    fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
 
 
1177
    exitcode = EXIT_FAILURE;
 
1232
1182
    AvahiServerConfig config;
 
1233
1183
    /* Do not publish any local Zeroconf records */
 
 
1257
1207
  /* Create the Avahi service browser */
 
1258
1208
  sb = avahi_s_service_browser_new(mc.server, if_index,
 
1259
 
                                   AVAHI_PROTO_UNSPEC, "_mandos._tcp",
 
1260
 
                                   NULL, 0, browse_callback, NULL);
 
 
1209
                                   AVAHI_PROTO_INET6, "_mandos._tcp",
 
 
1210
                                   NULL, 0, browse_callback, &mc);
 
1261
1211
  if(sb == NULL){
 
1262
1212
    fprintf(stderr, "Failed to create service browser: %s\n",
 
1263
1213
            avahi_strerror(avahi_server_errno(mc.server)));