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,
508
519
fprintf_plus(stderr, "GnuTLS: %s", string);
511
__attribute__((nonnull, warn_unused_result))
522
__attribute__((nonnull(1, 2, 4), warn_unused_result))
512
523
static int init_gnutls_global(const char *pubkeyfilename,
513
524
const char *seckeyfilename,
525
const char *dhparamsfilename,
514
526
mandos_context *mc){
518
531
fprintf_plus(stderr, "Initializing GnuTLS\n");
521
ret = gnutls_global_init();
522
if(ret != GNUTLS_E_SUCCESS){
523
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
524
safer_gnutls_strerror(ret));
529
535
/* "Use a log level over 10 to enable all debugging options."
530
536
* - GnuTLS manual
569
574
safer_gnutls_strerror(ret));
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));
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;
617
if(params.data == NULL){
618
dhparamsfilename = NULL;
620
if(dhparamsfilename == NULL){
623
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
624
GNUTLS_X509_FMT_PEM);
625
if(ret != GNUTLS_E_SUCCESS){
626
fprintf_plus(stderr, "Failed to parse DH parameters in file"
627
" \"%s\": %s\n", dhparamsfilename,
628
safer_gnutls_strerror(ret));
629
dhparamsfilename = NULL;
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 };
640
int secfile = open(seckeyfilename, O_RDONLY);
645
size_t buffer_capacity = 0;
647
buffer_capacity = incbuffer((char **)&buffer.data,
649
(size_t)buffer_capacity);
650
if(buffer_capacity == 0){
651
perror_plus("incbuffer");
656
ssize_t bytes_read = read(secfile,
657
buffer.data + buffer.size,
663
/* check bytes_read for failure */
670
buffer.size += (unsigned int)bytes_read;
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){
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"
683
safer_gnutls_strerror(ret));
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));
697
/* Use private key to suggest an appropriate
699
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
700
gnutls_openpgp_privkey_deinit(privkey);
702
fprintf_plus(stderr, "This OpenPGP key implies using"
703
" a GnuTLS security parameter \"%s\".\n",
704
safe_string(gnutls_sec_param_get_name
710
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
711
/* Err on the side of caution */
712
sec_param = GNUTLS_SEC_PARAM_ULTRA;
714
fprintf_plus(stderr, "Falling back to security parameter"
716
safe_string(gnutls_sec_param_get_name
721
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
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
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
736
safer_gnutls_strerror(ret));
740
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
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));
579
751
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
650
819
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
651
820
__attribute__((unused)) const char *txt){}
822
/* Set effective uid to 0, return errno */
823
__attribute__((warn_unused_result))
824
int raise_privileges(void){
825
int old_errno = errno;
827
if(seteuid(0) == -1){
834
/* Set effective and real user ID to 0. Return errno. */
835
__attribute__((warn_unused_result))
836
int raise_privileges_permanently(void){
837
int old_errno = errno;
838
int ret = raise_privileges();
850
/* Set effective user ID to unprivileged saved user ID */
851
__attribute__((warn_unused_result))
852
int lower_privileges(void){
853
int old_errno = errno;
855
if(seteuid(uid) == -1){
862
/* Lower privileges permanently */
863
__attribute__((warn_unused_result))
864
int lower_privileges_permanently(void){
865
int old_errno = errno;
867
if(setuid(uid) == -1){
874
/* Helper function to add_local_route() and delete_local_route() */
875
__attribute__((nonnull, warn_unused_result))
876
static bool add_delete_local_route(const bool add,
878
AvahiIfIndex if_index){
880
char helper[] = "mandos-client-iprouteadddel";
881
char add_arg[] = "add";
882
char delete_arg[] = "delete";
883
char debug_flag[] = "--debug";
884
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
885
if(pluginhelperdir == NULL){
887
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
888
" variable not set; cannot run helper\n");
893
char interface[IF_NAMESIZE];
894
if(if_indextoname((unsigned int)if_index, interface) == NULL){
895
perror_plus("if_indextoname");
899
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
901
perror_plus("open(\"/dev/null\", O_RDONLY)");
907
/* Raise privileges */
908
errno = raise_privileges_permanently();
910
perror_plus("Failed to raise privileges");
911
/* _exit(EX_NOPERM); */
917
perror_plus("setgid");
920
/* Reset supplementary groups */
922
ret = setgroups(0, NULL);
924
perror_plus("setgroups");
928
ret = dup2(devnull, STDIN_FILENO);
930
perror_plus("dup2(devnull, STDIN_FILENO)");
933
ret = close(devnull);
935
perror_plus("close");
938
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
940
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
943
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
948
if(helperdir_fd == -1){
950
_exit(EX_UNAVAILABLE);
952
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
955
perror_plus("openat");
957
_exit(EX_UNAVAILABLE);
961
#pragma GCC diagnostic push
962
#pragma GCC diagnostic ignored "-Wcast-qual"
964
if(fexecve(helper_fd, (char *const [])
965
{ helper, add ? add_arg : delete_arg, (char *)address,
966
interface, debug ? debug_flag : NULL, NULL },
969
#pragma GCC diagnostic pop
971
perror_plus("fexecve");
983
pret = waitpid(pid, &status, 0);
984
if(pret == -1 and errno == EINTR and quit_now){
985
int errno_raising = 0;
986
if((errno = raise_privileges()) != 0){
987
errno_raising = errno;
988
perror_plus("Failed to raise privileges in order to"
989
" kill helper program");
991
if(kill(pid, SIGTERM) == -1){
994
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
995
perror_plus("Failed to lower privileges after killing"
1000
} while(pret == -1 and errno == EINTR);
1002
perror_plus("waitpid");
1005
if(WIFEXITED(status)){
1006
if(WEXITSTATUS(status) != 0){
1007
fprintf_plus(stderr, "Error: iprouteadddel exited"
1008
" with status %d\n", WEXITSTATUS(status));
1013
if(WIFSIGNALED(status)){
1014
fprintf_plus(stderr, "Error: iprouteadddel died by"
1015
" signal %d\n", WTERMSIG(status));
1018
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1022
__attribute__((nonnull, warn_unused_result))
1023
static bool add_local_route(const char *address,
1024
AvahiIfIndex if_index){
1026
fprintf_plus(stderr, "Adding route to %s\n", address);
1028
return add_delete_local_route(true, address, if_index);
1031
__attribute__((nonnull, warn_unused_result))
1032
static bool delete_local_route(const char *address,
1033
AvahiIfIndex if_index){
1035
fprintf_plus(stderr, "Removing route to %s\n", address);
1037
return add_delete_local_route(false, address, if_index);
653
1040
/* Called when a Mandos server is found */
654
1041
__attribute__((nonnull, warn_unused_result))
655
1042
static int start_mandos_communication(const char *ip, in_port_t port,
742
1131
goto mandos_end;
745
memset(&to, 0, sizeof(to));
746
1134
if(af == AF_INET6){
747
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
748
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
1135
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1136
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1137
ret = inet_pton(af, ip, &to6->sin6_addr);
749
1138
} else { /* IPv4 */
750
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
751
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
1139
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1140
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1141
ret = inet_pton(af, ip, &to4->sin_addr);
824
1214
goto mandos_end;
828
ret = connect(tcp_sd, (struct sockaddr *)&to,
829
sizeof(struct sockaddr_in6));
831
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
832
sizeof(struct sockaddr_in));
835
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
837
perror_plus("connect");
1219
ret = connect(tcp_sd, (struct sockaddr *)&to,
1220
sizeof(struct sockaddr_in6));
1222
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1223
sizeof(struct sockaddr_in));
1226
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1227
and if_index != AVAHI_IF_UNSPEC
1228
and connect_to == NULL
1229
and not route_added and
1230
((af == AF_INET6 and not
1231
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1233
or (af == AF_INET and
1234
/* Not a a IPv4LL address */
1235
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1236
& 0xFFFF0000L) != 0xA9FE0000L))){
1237
/* Work around Avahi bug - Avahi does not announce link-local
1238
addresses if it has a global address, so local hosts with
1239
*only* a link-local address (e.g. Mandos clients) cannot
1240
connect to a Mandos server announced by Avahi on a server
1241
host with a global address. Work around this by retrying
1242
with an explicit route added with the server's address.
1244
Avahi bug reference:
1245
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1246
https://bugs.debian.org/587961
1249
fprintf_plus(stderr, "Mandos server unreachable, trying"
1253
route_added = add_local_route(ip, if_index);
1259
if(errno != ECONNREFUSED or debug){
1261
perror_plus("connect");
848
1274
const char *out = mandos_protocol_version;
1465
/* Set effective uid to 0, return errno */
1466
__attribute__((warn_unused_result))
1467
error_t raise_privileges(void){
1468
error_t old_errno = errno;
1469
error_t ret_errno = 0;
1470
if(seteuid(0) == -1){
1477
/* Set effective and real user ID to 0. Return errno. */
1478
__attribute__((warn_unused_result))
1479
error_t raise_privileges_permanently(void){
1480
error_t old_errno = errno;
1481
error_t ret_errno = raise_privileges();
1486
if(setuid(0) == -1){
1493
/* Set effective user ID to unprivileged saved user ID */
1494
__attribute__((warn_unused_result))
1495
error_t lower_privileges(void){
1496
error_t old_errno = errno;
1497
error_t ret_errno = 0;
1498
if(seteuid(uid) == -1){
1505
/* Lower privileges permanently */
1506
__attribute__((warn_unused_result))
1507
error_t lower_privileges_permanently(void){
1508
error_t old_errno = errno;
1509
error_t ret_errno = 0;
1510
if(setuid(uid) == -1){
1517
1910
__attribute__((nonnull))
1518
1911
void run_network_hooks(const char *mode, const char *interface,
1519
1912
const float delay){
1520
1913
struct dirent **direntries = NULL;
1521
1914
if(hookdir_fd == -1){
1522
hookdir_fd = open(hookdir, O_RDONLY);
1915
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1523
1917
if(hookdir_fd == -1){
1524
1918
if(errno == ENOENT){
1536
#if __GLIBC_PREREQ(2, 15)
1929
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1931
perror_plus("open(\"/dev/null\", O_RDONLY)");
1537
1934
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1538
1935
runnable_hook, alphasort);
1539
#else /* not __GLIBC_PREREQ(2, 15) */
1540
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1542
#endif /* not __GLIBC_PREREQ(2, 15) */
1543
#else /* not __GLIBC__ */
1544
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1546
#endif /* not __GLIBC__ */
1547
1936
if(numhooks == -1){
1548
1937
perror_plus("scandir");
1551
1941
struct dirent *direntry;
1553
int devnull = open("/dev/null", O_RDONLY);
1554
1943
for(int i = 0; i < numhooks; i++){
1555
1944
direntry = direntries[i];
2623
3054
free(interfaces_to_take_down);
2624
3055
free(interfaces_hooks);
3057
void clean_dir_at(int base, const char * const dirname,
3059
struct dirent **direntries = NULL;
3061
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3067
perror_plus("open");
3070
int numentries = scandirat(dir_fd, ".", &direntries,
3071
notdotentries, alphasort);
3072
if(numentries >= 0){
3073
for(int i = 0; i < numentries; i++){
3075
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3076
dirname, direntries[i]->d_name);
3078
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3080
if(errno == EISDIR){
3081
dret = unlinkat(dir_fd, direntries[i]->d_name,
3084
if((dret == -1) and (errno == ENOTEMPTY)
3085
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3086
== 0) and (level == 0)){
3087
/* Recurse only in this special case */
3088
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3091
if((dret == -1) and (errno != ENOENT)){
3092
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3093
direntries[i]->d_name, strerror(errno));
3096
free(direntries[i]);
3099
/* need to clean even if 0 because man page doesn't specify */
3101
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3102
if(dret == -1 and errno != ENOENT){
3103
perror_plus("rmdir");
3106
perror_plus("scandirat");
2626
3111
/* Removes the GPGME temp directory and all files inside */
2627
3112
if(tempdir != NULL){
2628
struct dirent **direntries = NULL;
2629
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2631
if(tempdir_fd == -1){
2632
perror_plus("open");
2635
#if __GLIBC_PREREQ(2, 15)
2636
int numentries = scandirat(tempdir_fd, ".", &direntries,
2637
notdotentries, alphasort);
2638
#else /* not __GLIBC_PREREQ(2, 15) */
2639
int numentries = scandir(tempdir, &direntries, notdotentries,
2641
#endif /* not __GLIBC_PREREQ(2, 15) */
2642
#else /* not __GLIBC__ */
2643
int numentries = scandir(tempdir, &direntries, notdotentries,
2645
#endif /* not __GLIBC__ */
2646
if(numentries >= 0){
2647
for(int i = 0; i < numentries; i++){
2648
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2650
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2651
" \"%s\", 0): %s\n", tempdir,
2652
direntries[i]->d_name, strerror(errno));
2654
free(direntries[i]);
2657
/* need to clean even if 0 because man page doesn't specify */
2659
if(numentries == -1){
2660
perror_plus("scandir");
2662
ret = rmdir(tempdir);
2663
if(ret == -1 and errno != ENOENT){
2664
perror_plus("rmdir");
2667
TEMP_FAILURE_RETRY(close(tempdir_fd));
3113
clean_dir_at(-1, tempdir, 0);