9
9
* "browse_callback", and parts of "main".
11
11
* Everything else is
12
* Copyright © 2008-2014 Teddy Hogeborn
13
* Copyright © 2008-2014 Björn Påhlsson
15
* This program is free software: you can redistribute it and/or
16
* modify it under the terms of the GNU General Public License as
17
* published by the Free Software Foundation, either version 3 of the
18
* License, or (at your option) any later version.
20
* This program is distributed in the hope that it will be useful, but
12
* Copyright © 2008-2018 Teddy Hogeborn
13
* Copyright © 2008-2018 Björn Påhlsson
15
* This file is part of Mandos.
17
* Mandos is free software: you can redistribute it and/or modify it
18
* under the terms of the GNU General Public License as published by
19
* the Free Software Foundation, either version 3 of the License, or
20
* (at your option) any later version.
22
* Mandos is distributed in the hope that it will be useful, but
21
23
* WITHOUT ANY WARRANTY; without even the implied warranty of
22
24
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23
25
* General Public License for more details.
25
27
* You should have received a copy of the GNU General Public License
26
* along with this program. If not, see
27
* <http://www.gnu.org/licenses/>.
28
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
29
30
* Contact the authors at <mandos@recompile.se>.
46
47
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
48
strtof(), abort() */
48
49
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
50
#include <string.h> /* strcmp(), strlen(), strerror(),
51
asprintf(), strncpy(), strsignal()
51
53
#include <sys/ioctl.h> /* ioctl */
52
54
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
55
sockaddr_in6, PF_INET6,
57
59
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
60
inet_pton(), connect(),
60
#include <fcntl.h> /* open(), unlinkat() */
62
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
61
63
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
65
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
65
#include <errno.h> /* perror(), errno,
67
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
68
EAI_SYSTEM, ENETUNREACH,
69
EHOSTUNREACH, ECONNREFUSED, EPROTO,
70
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
66
72
program_invocation_short_name */
67
73
#include <time.h> /* nanosleep(), time(), sleep() */
68
74
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
404
418
if(result == NULL){
405
419
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
407
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
408
result->unsupported_algorithm);
409
fprintf_plus(stderr, "Wrong key usage: %u\n",
410
result->wrong_key_usage);
421
if(result->unsupported_algorithm != NULL) {
422
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
423
result->unsupported_algorithm);
425
fprintf_plus(stderr, "Wrong key usage: %s\n",
426
result->wrong_key_usage ? "Yes" : "No");
411
427
if(result->file_name != NULL){
412
428
fprintf_plus(stderr, "File name: %s\n", result->file_name);
498
519
fprintf_plus(stderr, "GnuTLS: %s", string);
501
__attribute__((nonnull, warn_unused_result))
522
__attribute__((nonnull(1, 2, 4), warn_unused_result))
502
523
static int init_gnutls_global(const char *pubkeyfilename,
503
524
const char *seckeyfilename,
525
const char *dhparamsfilename,
504
526
mandos_context *mc){
508
531
fprintf_plus(stderr, "Initializing GnuTLS\n");
511
ret = gnutls_global_init();
512
if(ret != GNUTLS_E_SUCCESS){
513
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
514
safer_gnutls_strerror(ret));
519
535
/* "Use a log level over 10 to enable all debugging options."
520
536
* - GnuTLS manual
559
574
safer_gnutls_strerror(ret));
562
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
563
if(ret != GNUTLS_E_SUCCESS){
564
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
565
safer_gnutls_strerror(ret));
577
/* If a Diffie-Hellman parameters file was given, try to use it */
578
if(dhparamsfilename != NULL){
579
gnutls_datum_t params = { .data = NULL, .size = 0 };
581
int dhpfile = open(dhparamsfilename, O_RDONLY);
584
dhparamsfilename = NULL;
587
size_t params_capacity = 0;
589
params_capacity = incbuffer((char **)¶ms.data,
591
(size_t)params_capacity);
592
if(params_capacity == 0){
593
perror_plus("incbuffer");
596
dhparamsfilename = NULL;
599
ssize_t bytes_read = read(dhpfile,
600
params.data + params.size,
606
/* check bytes_read for failure */
611
dhparamsfilename = NULL;
614
params.size += (unsigned int)bytes_read;
616
ret = close(dhpfile);
618
perror_plus("close");
620
if(params.data == NULL){
621
dhparamsfilename = NULL;
623
if(dhparamsfilename == NULL){
626
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
627
GNUTLS_X509_FMT_PEM);
628
if(ret != GNUTLS_E_SUCCESS){
629
fprintf_plus(stderr, "Failed to parse DH parameters in file"
630
" \"%s\": %s\n", dhparamsfilename,
631
safer_gnutls_strerror(ret));
632
dhparamsfilename = NULL;
637
if(dhparamsfilename == NULL){
638
if(mc->dh_bits == 0){
639
/* Find out the optimal number of DH bits */
640
/* Try to read the private key file */
641
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
643
int secfile = open(seckeyfilename, O_RDONLY);
648
size_t buffer_capacity = 0;
650
buffer_capacity = incbuffer((char **)&buffer.data,
652
(size_t)buffer_capacity);
653
if(buffer_capacity == 0){
654
perror_plus("incbuffer");
659
ssize_t bytes_read = read(secfile,
660
buffer.data + buffer.size,
666
/* check bytes_read for failure */
673
buffer.size += (unsigned int)bytes_read;
677
/* If successful, use buffer to parse private key */
678
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
679
if(buffer.data != NULL){
681
gnutls_openpgp_privkey_t privkey = NULL;
682
ret = gnutls_openpgp_privkey_init(&privkey);
683
if(ret != GNUTLS_E_SUCCESS){
684
fprintf_plus(stderr, "Error initializing OpenPGP key"
686
safer_gnutls_strerror(ret));
690
ret = gnutls_openpgp_privkey_import
691
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
692
if(ret != GNUTLS_E_SUCCESS){
693
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
694
safer_gnutls_strerror(ret));
700
/* Use private key to suggest an appropriate
702
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
703
gnutls_openpgp_privkey_deinit(privkey);
705
fprintf_plus(stderr, "This OpenPGP key implies using"
706
" a GnuTLS security parameter \"%s\".\n",
707
safe_string(gnutls_sec_param_get_name
713
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
714
/* Err on the side of caution */
715
sec_param = GNUTLS_SEC_PARAM_ULTRA;
717
fprintf_plus(stderr, "Falling back to security parameter"
719
safe_string(gnutls_sec_param_get_name
724
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
728
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
729
" implies %u DH bits; using that.\n",
730
safe_string(gnutls_sec_param_get_name
735
fprintf_plus(stderr, "Failed to get implied number of DH"
736
" bits for security parameter \"%s\"): %s\n",
737
safe_string(gnutls_sec_param_get_name
739
safer_gnutls_strerror(ret));
743
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
746
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
747
if(ret != GNUTLS_E_SUCCESS){
748
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
749
" bits): %s\n", mc->dh_bits,
750
safer_gnutls_strerror(ret));
569
754
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
640
822
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
641
823
__attribute__((unused)) const char *txt){}
825
/* Set effective uid to 0, return errno */
826
__attribute__((warn_unused_result))
827
int raise_privileges(void){
828
int old_errno = errno;
830
if(seteuid(0) == -1){
837
/* Set effective and real user ID to 0. Return errno. */
838
__attribute__((warn_unused_result))
839
int raise_privileges_permanently(void){
840
int old_errno = errno;
841
int ret = raise_privileges();
853
/* Set effective user ID to unprivileged saved user ID */
854
__attribute__((warn_unused_result))
855
int lower_privileges(void){
856
int old_errno = errno;
858
if(seteuid(uid) == -1){
865
/* Lower privileges permanently */
866
__attribute__((warn_unused_result))
867
int lower_privileges_permanently(void){
868
int old_errno = errno;
870
if(setuid(uid) == -1){
877
/* Helper function to add_local_route() and delete_local_route() */
878
__attribute__((nonnull, warn_unused_result))
879
static bool add_delete_local_route(const bool add,
881
AvahiIfIndex if_index){
883
char helper[] = "mandos-client-iprouteadddel";
884
char add_arg[] = "add";
885
char delete_arg[] = "delete";
886
char debug_flag[] = "--debug";
887
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
888
if(pluginhelperdir == NULL){
890
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
891
" variable not set; cannot run helper\n");
896
char interface[IF_NAMESIZE];
897
if(if_indextoname((unsigned int)if_index, interface) == NULL){
898
perror_plus("if_indextoname");
902
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
904
perror_plus("open(\"/dev/null\", O_RDONLY)");
910
/* Raise privileges */
911
errno = raise_privileges_permanently();
913
perror_plus("Failed to raise privileges");
914
/* _exit(EX_NOPERM); */
920
perror_plus("setgid");
923
/* Reset supplementary groups */
925
ret = setgroups(0, NULL);
927
perror_plus("setgroups");
931
ret = dup2(devnull, STDIN_FILENO);
933
perror_plus("dup2(devnull, STDIN_FILENO)");
936
ret = close(devnull);
938
perror_plus("close");
941
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
943
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
946
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
951
if(helperdir_fd == -1){
953
_exit(EX_UNAVAILABLE);
955
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
958
perror_plus("openat");
960
_exit(EX_UNAVAILABLE);
964
#pragma GCC diagnostic push
965
#pragma GCC diagnostic ignored "-Wcast-qual"
967
if(fexecve(helper_fd, (char *const [])
968
{ helper, add ? add_arg : delete_arg, (char *)address,
969
interface, debug ? debug_flag : NULL, NULL },
972
#pragma GCC diagnostic pop
974
perror_plus("fexecve");
986
pret = waitpid(pid, &status, 0);
987
if(pret == -1 and errno == EINTR and quit_now){
988
int errno_raising = 0;
989
if((errno = raise_privileges()) != 0){
990
errno_raising = errno;
991
perror_plus("Failed to raise privileges in order to"
992
" kill helper program");
994
if(kill(pid, SIGTERM) == -1){
997
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
998
perror_plus("Failed to lower privileges after killing"
1003
} while(pret == -1 and errno == EINTR);
1005
perror_plus("waitpid");
1008
if(WIFEXITED(status)){
1009
if(WEXITSTATUS(status) != 0){
1010
fprintf_plus(stderr, "Error: iprouteadddel exited"
1011
" with status %d\n", WEXITSTATUS(status));
1016
if(WIFSIGNALED(status)){
1017
fprintf_plus(stderr, "Error: iprouteadddel died by"
1018
" signal %d\n", WTERMSIG(status));
1021
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1025
__attribute__((nonnull, warn_unused_result))
1026
static bool add_local_route(const char *address,
1027
AvahiIfIndex if_index){
1029
fprintf_plus(stderr, "Adding route to %s\n", address);
1031
return add_delete_local_route(true, address, if_index);
1034
__attribute__((nonnull, warn_unused_result))
1035
static bool delete_local_route(const char *address,
1036
AvahiIfIndex if_index){
1038
fprintf_plus(stderr, "Removing route to %s\n", address);
1040
return add_delete_local_route(false, address, if_index);
643
1043
/* Called when a Mandos server is found */
644
1044
__attribute__((nonnull, warn_unused_result))
645
1045
static int start_mandos_communication(const char *ip, in_port_t port,
732
1134
goto mandos_end;
735
memset(&to, 0, sizeof(to));
736
1137
if(af == AF_INET6){
737
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
738
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
1138
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1139
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1140
ret = inet_pton(af, ip, &to6->sin6_addr);
739
1141
} else { /* IPv4 */
740
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
741
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
1142
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1143
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1144
ret = inet_pton(af, ip, &to4->sin_addr);
814
1217
goto mandos_end;
818
ret = connect(tcp_sd, (struct sockaddr *)&to,
819
sizeof(struct sockaddr_in6));
821
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
822
sizeof(struct sockaddr_in));
825
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
827
perror_plus("connect");
1222
ret = connect(tcp_sd, (struct sockaddr *)&to,
1223
sizeof(struct sockaddr_in6));
1225
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1226
sizeof(struct sockaddr_in));
1229
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1230
and if_index != AVAHI_IF_UNSPEC
1231
and connect_to == NULL
1232
and not route_added and
1233
((af == AF_INET6 and not
1234
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1236
or (af == AF_INET and
1237
/* Not a a IPv4LL address */
1238
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1239
& 0xFFFF0000L) != 0xA9FE0000L))){
1240
/* Work around Avahi bug - Avahi does not announce link-local
1241
addresses if it has a global address, so local hosts with
1242
*only* a link-local address (e.g. Mandos clients) cannot
1243
connect to a Mandos server announced by Avahi on a server
1244
host with a global address. Work around this by retrying
1245
with an explicit route added with the server's address.
1247
Avahi bug reference:
1248
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1249
https://bugs.debian.org/587961
1252
fprintf_plus(stderr, "Mandos server unreachable, trying"
1256
route_added = add_local_route(ip, if_index);
1262
if(errno != ECONNREFUSED or debug){
1264
perror_plus("connect");
838
1277
const char *out = mandos_protocol_version;
1454
/* Set effective uid to 0, return errno */
1455
__attribute__((warn_unused_result))
1456
error_t raise_privileges(void){
1457
error_t old_errno = errno;
1458
error_t ret_errno = 0;
1459
if(seteuid(0) == -1){
1461
perror_plus("seteuid");
1467
/* Set effective and real user ID to 0. Return errno. */
1468
__attribute__((warn_unused_result))
1469
error_t raise_privileges_permanently(void){
1470
error_t old_errno = errno;
1471
error_t ret_errno = raise_privileges();
1476
if(setuid(0) == -1){
1478
perror_plus("seteuid");
1484
/* Set effective user ID to unprivileged saved user ID */
1485
__attribute__((warn_unused_result))
1486
error_t lower_privileges(void){
1487
error_t old_errno = errno;
1488
error_t ret_errno = 0;
1489
if(seteuid(uid) == -1){
1491
perror_plus("seteuid");
1497
/* Lower privileges permanently */
1498
__attribute__((warn_unused_result))
1499
error_t lower_privileges_permanently(void){
1500
error_t old_errno = errno;
1501
error_t ret_errno = 0;
1502
if(setuid(uid) == -1){
1504
perror_plus("setuid");
1510
1921
__attribute__((nonnull))
1511
1922
void run_network_hooks(const char *mode, const char *interface,
1512
1923
const float delay){
1513
struct dirent **direntries;
1924
struct dirent **direntries = NULL;
1514
1925
if(hookdir_fd == -1){
1515
hookdir_fd = open(hookdir, O_RDONLY);
1926
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1516
1928
if(hookdir_fd == -1){
1517
1929
if(errno == ENOENT){
1529
#if __GLIBC_PREREQ(2, 15)
1940
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1942
perror_plus("open(\"/dev/null\", O_RDONLY)");
1530
1945
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1531
1946
runnable_hook, alphasort);
1532
#else /* not __GLIBC_PREREQ(2, 15) */
1533
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1535
#endif /* not __GLIBC_PREREQ(2, 15) */
1536
#else /* not __GLIBC__ */
1537
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1539
#endif /* not __GLIBC__ */
1540
1947
if(numhooks == -1){
1541
1948
perror_plus("scandir");
1544
1952
struct dirent *direntry;
1546
int devnull = open("/dev/null", O_RDONLY);
1547
1954
for(int i = 0; i < numhooks; i++){
1548
1955
direntry = direntries[i];
2588
3065
free(interfaces_to_take_down);
2589
3066
free(interfaces_hooks);
3068
void clean_dir_at(int base, const char * const dirname,
3070
struct dirent **direntries = NULL;
3072
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3078
perror_plus("open");
3081
int numentries = scandirat(dir_fd, ".", &direntries,
3082
notdotentries, alphasort);
3083
if(numentries >= 0){
3084
for(int i = 0; i < numentries; i++){
3086
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3087
dirname, direntries[i]->d_name);
3089
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3091
if(errno == EISDIR){
3092
dret = unlinkat(dir_fd, direntries[i]->d_name,
3095
if((dret == -1) and (errno == ENOTEMPTY)
3096
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3097
== 0) and (level == 0)){
3098
/* Recurse only in this special case */
3099
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3102
if((dret == -1) and (errno != ENOENT)){
3103
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3104
direntries[i]->d_name, strerror(errno));
3107
free(direntries[i]);
3110
/* need to clean even if 0 because man page doesn't specify */
3112
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3113
if(dret == -1 and errno != ENOENT){
3114
perror_plus("rmdir");
3117
perror_plus("scandirat");
2591
3122
/* Removes the GPGME temp directory and all files inside */
2592
3123
if(tempdir != NULL){
2593
struct dirent **direntries = NULL;
2594
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2596
if(tempdir_fd == -1){
2597
perror_plus("open");
2600
#if __GLIBC_PREREQ(2, 15)
2601
int numentries = scandirat(tempdir_fd, ".", &direntries,
2602
notdotentries, alphasort);
2603
#else /* not __GLIBC_PREREQ(2, 15) */
2604
int numentries = scandir(tempdir, &direntries, notdotentries,
2606
#endif /* not __GLIBC_PREREQ(2, 15) */
2607
#else /* not __GLIBC__ */
2608
int numentries = scandir(tempdir, &direntries, notdotentries,
2610
#endif /* not __GLIBC__ */
2612
for(int i = 0; i < numentries; i++){
2613
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2615
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2616
" \"%s\", 0): %s\n", tempdir,
2617
direntries[i]->d_name, strerror(errno));
2621
/* need to clean even if 0 because man page doesn't specify */
2623
if(numentries == -1){
2624
perror_plus("scandir");
2626
ret = rmdir(tempdir);
2627
if(ret == -1 and errno != ENOENT){
2628
perror_plus("rmdir");
2631
TEMP_FAILURE_RETRY(close(tempdir_fd));
3124
clean_dir_at(-1, tempdir, 0);