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  • Committer: Teddy Hogeborn
  • Date: 2015-07-16 20:30:35 UTC
  • mto: (237.7.594 trunk)
  • mto: This revision was merged to the branch mainline in revision 325.
  • Revision ID: teddy@recompile.se-20150716203035-z7qjwm270o2vrjah
Assume the C11 language (ISO 9899:2011), when compiling C code.

* Makefile (LANGUAGE): Changed to "-std=gnu11".

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removed removed

Lines of Context:
plugins.d/mandos-client.c
493
493
  return plaintext_length;
494
494
}
495
495
 
 
496
__attribute__((warn_unused_result, const))
 
497
static const char *safe_string(const char *str){
 
498
  if(str == NULL)
 
499
    return "(unknown)";
 
500
  return str;
 
501
}
 
502
 
496
503
__attribute__((warn_unused_result))
497
504
static const char *safer_gnutls_strerror(int value){
498
505
  const char *ret = gnutls_strerror(value);
499
 
  if(ret == NULL)
500
 
    ret = "(unknown)";
501
 
  return ret;
 
506
  return safe_string(ret);
502
507
}
503
508
 
504
509
/* GnuTLS log function callback */
511
516
__attribute__((nonnull, warn_unused_result))
512
517
static int init_gnutls_global(const char *pubkeyfilename,
513
518
                              const char *seckeyfilename,
 
519
                              const char *dhparamsfilename,
514
520
                              mandos_context *mc){
515
521
  int ret;
 
522
  unsigned int uret;
516
523
  
517
524
  if(debug){
518
525
    fprintf_plus(stderr, "Initializing GnuTLS\n");
569
576
                 safer_gnutls_strerror(ret));
570
577
    goto globalfail;
571
578
  }
572
 
  ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
573
 
  if(ret != GNUTLS_E_SUCCESS){
574
 
    fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
575
 
                 safer_gnutls_strerror(ret));
576
 
    goto globalfail;
577
 
  }
578
 
  
 
579
  /* If a Diffie-Hellman parameters file was given, try to use it */
 
580
  if(dhparamsfilename != NULL){
 
581
    gnutls_datum_t params = { .data = NULL, .size = 0 };
 
582
    do {
 
583
      int dhpfile = open(dhparamsfilename, O_RDONLY);
 
584
      if(dhpfile == -1){
 
585
        perror_plus("open");
 
586
        dhparamsfilename = NULL;
 
587
        break;
 
588
      }
 
589
      size_t params_capacity = 0;
 
590
      while(true){
 
591
        params_capacity = incbuffer((char **)&params.data,
 
592
                                    (size_t)params.size,
 
593
                                    (size_t)params_capacity);
 
594
        if(params_capacity == 0){
 
595
          perror_plus("incbuffer");
 
596
          free(params.data);
 
597
          params.data = NULL;
 
598
          dhparamsfilename = NULL;
 
599
          break;
 
600
        }
 
601
        ssize_t bytes_read = read(dhpfile,
 
602
                                  params.data + params.size,
 
603
                                  BUFFER_SIZE);
 
604
        /* EOF */
 
605
        if(bytes_read == 0){
 
606
          break;
 
607
        }
 
608
        /* check bytes_read for failure */
 
609
        if(bytes_read < 0){
 
610
          perror_plus("read");
 
611
          free(params.data);
 
612
          params.data = NULL;
 
613
          dhparamsfilename = NULL;
 
614
          break;
 
615
        }
 
616
        params.size += (unsigned int)bytes_read;
 
617
      }
 
618
      if(params.data == NULL){
 
619
        dhparamsfilename = NULL;
 
620
      }
 
621
      if(dhparamsfilename == NULL){
 
622
        break;
 
623
      }
 
624
      ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,
 
625
                                          GNUTLS_X509_FMT_PEM);
 
626
      if(ret != GNUTLS_E_SUCCESS){
 
627
        fprintf_plus(stderr, "Failed to parse DH parameters in file"
 
628
                     " \"%s\": %s\n", dhparamsfilename,
 
629
                     safer_gnutls_strerror(ret));
 
630
        dhparamsfilename = NULL;
 
631
      }
 
632
    } while(false);
 
633
  }
 
634
  if(dhparamsfilename == NULL){
 
635
    if(mc->dh_bits == 0){
 
636
      /* Find out the optimal number of DH bits */
 
637
      /* Try to read the private key file */
 
638
      gnutls_datum_t buffer = { .data = NULL, .size = 0 };
 
639
      do {
 
640
        int secfile = open(seckeyfilename, O_RDONLY);
 
641
        if(secfile == -1){
 
642
          perror_plus("open");
 
643
          break;
 
644
        }
 
645
        size_t buffer_capacity = 0;
 
646
        while(true){
 
647
          buffer_capacity = incbuffer((char **)&buffer.data,
 
648
                                      (size_t)buffer.size,
 
649
                                      (size_t)buffer_capacity);
 
650
          if(buffer_capacity == 0){
 
651
            perror_plus("incbuffer");
 
652
            free(buffer.data);
 
653
            buffer.data = NULL;
 
654
            break;
 
655
          }
 
656
          ssize_t bytes_read = read(secfile,
 
657
                                    buffer.data + buffer.size,
 
658
                                    BUFFER_SIZE);
 
659
          /* EOF */
 
660
          if(bytes_read == 0){
 
661
            break;
 
662
          }
 
663
          /* check bytes_read for failure */
 
664
          if(bytes_read < 0){
 
665
            perror_plus("read");
 
666
            free(buffer.data);
 
667
            buffer.data = NULL;
 
668
            break;
 
669
          }
 
670
          buffer.size += (unsigned int)bytes_read;
 
671
        }
 
672
        close(secfile);
 
673
      } while(false);
 
674
      /* If successful, use buffer to parse private key */
 
675
      gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
 
676
      if(buffer.data != NULL){
 
677
        {
 
678
          gnutls_openpgp_privkey_t privkey = NULL;
 
679
          ret = gnutls_openpgp_privkey_init(&privkey);
 
680
          if(ret != GNUTLS_E_SUCCESS){
 
681
            fprintf_plus(stderr, "Error initializing OpenPGP key"
 
682
                         " structure: %s",
 
683
                         safer_gnutls_strerror(ret));
 
684
            free(buffer.data);
 
685
            buffer.data = NULL;
 
686
          } else {
 
687
            ret = gnutls_openpgp_privkey_import
 
688
              (privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
 
689
            if(ret != GNUTLS_E_SUCCESS){
 
690
              fprintf_plus(stderr, "Error importing OpenPGP key : %s",
 
691
                           safer_gnutls_strerror(ret));
 
692
              privkey = NULL;
 
693
            }
 
694
            free(buffer.data);
 
695
            buffer.data = NULL;
 
696
            if(privkey != NULL){
 
697
              /* Use private key to suggest an appropriate
 
698
                 sec_param */
 
699
              sec_param = gnutls_openpgp_privkey_sec_param(privkey);
 
700
              gnutls_openpgp_privkey_deinit(privkey);
 
701
              if(debug){
 
702
                fprintf_plus(stderr, "This OpenPGP key implies using"
 
703
                             " a GnuTLS security parameter \"%s\".\n",
 
704
                             safe_string(gnutls_sec_param_get_name
 
705
                                         (sec_param)));
 
706
              }
 
707
            }
 
708
          }
 
709
        }
 
710
        if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
 
711
          /* Err on the side of caution */
 
712
          sec_param = GNUTLS_SEC_PARAM_ULTRA;
 
713
          if(debug){
 
714
            fprintf_plus(stderr, "Falling back to security parameter"
 
715
                         " \"%s\"\n",
 
716
                         safe_string(gnutls_sec_param_get_name
 
717
                                     (sec_param)));
 
718
          }
 
719
        }
 
720
      }
 
721
      uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
 
722
      if(uret != 0){
 
723
        mc->dh_bits = uret;
 
724
        if(debug){
 
725
          fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
 
726
                       " implies %u DH bits; using that.\n",
 
727
                       safe_string(gnutls_sec_param_get_name
 
728
                                   (sec_param)),
 
729
                       mc->dh_bits);
 
730
        }
 
731
      } else {
 
732
        fprintf_plus(stderr, "Failed to get implied number of DH"
 
733
                     " bits for security parameter \"%s\"): %s\n",
 
734
                     safe_string(gnutls_sec_param_get_name
 
735
                                 (sec_param)),
 
736
                     safer_gnutls_strerror(ret));
 
737
        goto globalfail;
 
738
      }
 
739
    } else if(debug){
 
740
      fprintf_plus(stderr, "DH bits explicitly set to %u\n",
 
741
                   mc->dh_bits);
 
742
    }
 
743
    ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
 
744
    if(ret != GNUTLS_E_SUCCESS){
 
745
      fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
 
746
                   " bits): %s\n", mc->dh_bits,
 
747
                   safer_gnutls_strerror(ret));
 
748
      goto globalfail;
 
749
    }
 
750
  }
579
751
  gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
580
752
  
581
753
  return 0;
641
813
  /* ignore client certificate if any. */
642
814
  gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
643
815
  
644
 
  gnutls_dh_set_prime_bits(*session, mc->dh_bits);
645
 
  
646
816
  return 0;
647
817
}
648
818
 
702
872
  return ret_errno;
703
873
}
704
874
 
705
 
/* Helper function to add_local_route() and remove_local_route() */
 
875
/* Helper function to add_local_route() and delete_local_route() */
706
876
__attribute__((nonnull, warn_unused_result))
707
 
static bool add_remove_local_route(const bool add,
 
877
static bool add_delete_local_route(const bool add,
708
878
                                   const char *address,
709
879
                                   AvahiIfIndex if_index){
710
880
  int ret;
711
881
  char helper[] = "mandos-client-iprouteadddel";
712
882
  char add_arg[] = "add";
713
883
  char delete_arg[] = "delete";
 
884
  char debug_flag[] = "--debug";
714
885
  char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
715
886
  if(pluginhelperdir == NULL){
716
887
    if(debug){
792
963
#endif
793
964
    if(fexecve(helper_fd, (char *const [])
794
965
               { helper, add ? add_arg : delete_arg, (char *)address,
795
 
                   interface, NULL }, environ) == -1){
 
966
                   interface, debug ? debug_flag : NULL, NULL },
 
967
               environ) == -1){
796
968
#ifdef __GNUC__
797
969
#pragma GCC diagnostic pop
798
970
#endif
850
1022
__attribute__((nonnull, warn_unused_result))
851
1023
static bool add_local_route(const char *address,
852
1024
                            AvahiIfIndex if_index){
853
 
  return add_remove_local_route(true, address, if_index);
 
1025
  if(debug){
 
1026
    fprintf_plus(stderr, "Adding route to %s\n", address);
 
1027
  }
 
1028
  return add_delete_local_route(true, address, if_index);
854
1029
}
855
1030
 
856
1031
__attribute__((nonnull, warn_unused_result))
857
 
static bool remove_local_route(const char *address,
 
1032
static bool delete_local_route(const char *address,
858
1033
                               AvahiIfIndex if_index){
859
 
  return add_remove_local_route(false, address, if_index);
 
1034
  if(debug){
 
1035
    fprintf_plus(stderr, "Removing route to %s\n", address);
 
1036
  }
 
1037
  return add_delete_local_route(false, address, if_index);
860
1038
}
861
1039
 
862
1040
/* Called when a Mandos server is found */
1065
1243
           http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1066
1244
           https://bugs.debian.org/587961
1067
1245
        */
 
1246
        if(debug){
 
1247
          fprintf_plus(stderr, "Mandos server unreachable, trying"
 
1248
                       " direct route\n");
 
1249
        }
1068
1250
        int e = errno;
1069
1251
        route_added = add_local_route(ip, if_index);
1070
1252
        if(route_added){
1274
1456
 mandos_end:
1275
1457
  {
1276
1458
    if(route_added){
1277
 
      if(not remove_local_route(ip, if_index)){
1278
 
        fprintf_plus(stderr, "Failed to remove local route to %s on"
 
1459
      if(not delete_local_route(ip, if_index)){
 
1460
        fprintf_plus(stderr, "Failed to delete local route to %s on"
1279
1461
                     " interface %d", ip, if_index);
1280
1462
      }
1281
1463
    }
2103
2285
}
2104
2286
 
2105
2287
int main(int argc, char *argv[]){
2106
 
  mandos_context mc = { .server = NULL, .dh_bits = 1024,
 
2288
  mandos_context mc = { .server = NULL, .dh_bits = 0,
2107
2289
                        .priority = "SECURE256:!CTYPE-X.509:"
2108
 
                        "+CTYPE-OPENPGP", .current_server = NULL,
 
2290
                        "+CTYPE-OPENPGP:!RSA", .current_server = NULL,
2109
2291
                        .interfaces = NULL, .interfaces_size = 0 };
2110
2292
  AvahiSServiceBrowser *sb = NULL;
2111
2293
  error_t ret_errno;
2121
2303
  AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2122
2304
  const char *seckey = PATHDIR "/" SECKEY;
2123
2305
  const char *pubkey = PATHDIR "/" PUBKEY;
 
2306
  const char *dh_params_file = NULL;
2124
2307
  char *interfaces_hooks = NULL;
2125
2308
  
2126
2309
  bool gnutls_initialized = false;
2179
2362
        .doc = "Bit length of the prime number used in the"
2180
2363
        " Diffie-Hellman key exchange",
2181
2364
        .group = 2 },
 
2365
      { .name = "dh-params", .key = 134,
 
2366
        .arg = "FILE",
 
2367
        .doc = "PEM-encoded PKCS#3 file with pre-generated parameters"
 
2368
        " for the Diffie-Hellman key exchange",
 
2369
        .group = 2 },
2182
2370
      { .name = "priority", .key = 130,
2183
2371
        .arg = "STRING",
2184
2372
        .doc = "GnuTLS priority string for the TLS handshake",
2239
2427
        }
2240
2428
        mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2241
2429
        break;
 
2430
      case 134:                 /* --dh-params */
 
2431
        dh_params_file = arg;
 
2432
        break;
2242
2433
      case 130:                 /* --priority */
2243
2434
        mc.priority = arg;
2244
2435
        break;
2355
2546
        }
2356
2547
      }
2357
2548
      
 
2549
      if(strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
 
2550
        int dhparams_fd = open(dh_params_file, O_RDONLY);
 
2551
        if(dhparams_fd == -1){
 
2552
          perror_plus("open");
 
2553
        } else {
 
2554
          ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
 
2555
          if(ret == -1){
 
2556
            perror_plus("fstat");
 
2557
          } else {
 
2558
            if(S_ISREG(st.st_mode)
 
2559
               and st.st_uid == 0 and st.st_gid == 0){
 
2560
              ret = fchown(dhparams_fd, uid, gid);
 
2561
              if(ret == -1){
 
2562
                perror_plus("fchown");
 
2563
              }
 
2564
            }
 
2565
          }
 
2566
          TEMP_FAILURE_RETRY(close(dhparams_fd));
 
2567
        }
 
2568
      }
 
2569
      
2358
2570
      /* Lower privileges */
2359
2571
      ret_errno = lower_privileges();
2360
2572
      if(ret_errno != 0){
2534
2746
      errno = bring_up_interface(interface, delay);
2535
2747
      if(not interface_was_up){
2536
2748
        if(errno != 0){
2537
 
          perror_plus("Failed to bring up interface");
 
2749
          fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
 
2750
                       " %s\n", interface, strerror(errno));
2538
2751
        } else {
2539
2752
          errno = argz_add(&interfaces_to_take_down,
2540
2753
                           &interfaces_to_take_down_size,
2563
2776
    goto end;
2564
2777
  }
2565
2778
  
2566
 
  ret = init_gnutls_global(pubkey, seckey, &mc);
 
2779
  ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
2567
2780
  if(ret == -1){
2568
2781
    fprintf_plus(stderr, "init_gnutls_global failed\n");
2569
2782
    exitcode = EX_UNAVAILABLE;