40
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
47
strtof(), abort() */
48
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
49
#include <string.h> /* strcmp(), strlen(), strerror(),
50
asprintf(), strncpy() */
51
51
#include <sys/ioctl.h> /* ioctl */
52
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
53
sockaddr_in6, PF_INET6,
57
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
58
inet_pton(), connect(),
60
#include <fcntl.h> /* open() */
60
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
61
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
65
#include <errno.h> /* perror(), errno,
65
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
66
EAI_SYSTEM, ENETUNREACH,
67
EHOSTUNREACH, ECONNREFUSED, EPROTO,
68
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
66
70
program_invocation_short_name */
67
71
#include <time.h> /* nanosleep(), time(), sleep() */
68
72
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
497
517
fprintf_plus(stderr, "GnuTLS: %s", string);
500
__attribute__((nonnull, warn_unused_result))
520
__attribute__((nonnull(1, 2, 4), warn_unused_result))
501
521
static int init_gnutls_global(const char *pubkeyfilename,
502
522
const char *seckeyfilename,
523
const char *dhparamsfilename,
503
524
mandos_context *mc){
507
529
fprintf_plus(stderr, "Initializing GnuTLS\n");
510
ret = gnutls_global_init();
511
if(ret != GNUTLS_E_SUCCESS){
512
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
513
safer_gnutls_strerror(ret));
518
533
/* "Use a log level over 10 to enable all debugging options."
519
534
* - GnuTLS manual
558
572
safer_gnutls_strerror(ret));
561
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
562
if(ret != GNUTLS_E_SUCCESS){
563
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
564
safer_gnutls_strerror(ret));
575
/* If a Diffie-Hellman parameters file was given, try to use it */
576
if(dhparamsfilename != NULL){
577
gnutls_datum_t params = { .data = NULL, .size = 0 };
579
int dhpfile = open(dhparamsfilename, O_RDONLY);
582
dhparamsfilename = NULL;
585
size_t params_capacity = 0;
587
params_capacity = incbuffer((char **)¶ms.data,
589
(size_t)params_capacity);
590
if(params_capacity == 0){
591
perror_plus("incbuffer");
594
dhparamsfilename = NULL;
597
ssize_t bytes_read = read(dhpfile,
598
params.data + params.size,
604
/* check bytes_read for failure */
609
dhparamsfilename = NULL;
612
params.size += (unsigned int)bytes_read;
614
if(params.data == NULL){
615
dhparamsfilename = NULL;
617
if(dhparamsfilename == NULL){
620
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
621
GNUTLS_X509_FMT_PEM);
622
if(ret != GNUTLS_E_SUCCESS){
623
fprintf_plus(stderr, "Failed to parse DH parameters in file"
624
" \"%s\": %s\n", dhparamsfilename,
625
safer_gnutls_strerror(ret));
626
dhparamsfilename = NULL;
630
if(dhparamsfilename == NULL){
631
if(mc->dh_bits == 0){
632
/* Find out the optimal number of DH bits */
633
/* Try to read the private key file */
634
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
636
int secfile = open(seckeyfilename, O_RDONLY);
641
size_t buffer_capacity = 0;
643
buffer_capacity = incbuffer((char **)&buffer.data,
645
(size_t)buffer_capacity);
646
if(buffer_capacity == 0){
647
perror_plus("incbuffer");
652
ssize_t bytes_read = read(secfile,
653
buffer.data + buffer.size,
659
/* check bytes_read for failure */
666
buffer.size += (unsigned int)bytes_read;
670
/* If successful, use buffer to parse private key */
671
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
672
if(buffer.data != NULL){
674
gnutls_openpgp_privkey_t privkey = NULL;
675
ret = gnutls_openpgp_privkey_init(&privkey);
676
if(ret != GNUTLS_E_SUCCESS){
677
fprintf_plus(stderr, "Error initializing OpenPGP key"
679
safer_gnutls_strerror(ret));
683
ret = gnutls_openpgp_privkey_import
684
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
685
if(ret != GNUTLS_E_SUCCESS){
686
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
687
safer_gnutls_strerror(ret));
693
/* Use private key to suggest an appropriate
695
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
696
gnutls_openpgp_privkey_deinit(privkey);
698
fprintf_plus(stderr, "This OpenPGP key implies using"
699
" a GnuTLS security parameter \"%s\".\n",
700
safe_string(gnutls_sec_param_get_name
706
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
707
/* Err on the side of caution */
708
sec_param = GNUTLS_SEC_PARAM_ULTRA;
710
fprintf_plus(stderr, "Falling back to security parameter"
712
safe_string(gnutls_sec_param_get_name
717
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
721
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
722
" implies %u DH bits; using that.\n",
723
safe_string(gnutls_sec_param_get_name
728
fprintf_plus(stderr, "Failed to get implied number of DH"
729
" bits for security parameter \"%s\"): %s\n",
730
safe_string(gnutls_sec_param_get_name
732
safer_gnutls_strerror(ret));
736
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
739
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
740
if(ret != GNUTLS_E_SUCCESS){
741
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
742
" bits): %s\n", mc->dh_bits,
743
safer_gnutls_strerror(ret));
568
747
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
639
815
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
640
816
__attribute__((unused)) const char *txt){}
818
/* Set effective uid to 0, return errno */
819
__attribute__((warn_unused_result))
820
int raise_privileges(void){
821
int old_errno = errno;
823
if(seteuid(0) == -1){
830
/* Set effective and real user ID to 0. Return errno. */
831
__attribute__((warn_unused_result))
832
int raise_privileges_permanently(void){
833
int old_errno = errno;
834
int ret = raise_privileges();
846
/* Set effective user ID to unprivileged saved user ID */
847
__attribute__((warn_unused_result))
848
int lower_privileges(void){
849
int old_errno = errno;
851
if(seteuid(uid) == -1){
858
/* Lower privileges permanently */
859
__attribute__((warn_unused_result))
860
int lower_privileges_permanently(void){
861
int old_errno = errno;
863
if(setuid(uid) == -1){
870
/* Helper function to add_local_route() and delete_local_route() */
871
__attribute__((nonnull, warn_unused_result))
872
static bool add_delete_local_route(const bool add,
874
AvahiIfIndex if_index){
876
char helper[] = "mandos-client-iprouteadddel";
877
char add_arg[] = "add";
878
char delete_arg[] = "delete";
879
char debug_flag[] = "--debug";
880
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
881
if(pluginhelperdir == NULL){
883
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
884
" variable not set; cannot run helper\n");
889
char interface[IF_NAMESIZE];
890
if(if_indextoname((unsigned int)if_index, interface) == NULL){
891
perror_plus("if_indextoname");
895
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
897
perror_plus("open(\"/dev/null\", O_RDONLY)");
903
/* Raise privileges */
904
errno = raise_privileges_permanently();
906
perror_plus("Failed to raise privileges");
907
/* _exit(EX_NOPERM); */
913
perror_plus("setgid");
916
/* Reset supplementary groups */
918
ret = setgroups(0, NULL);
920
perror_plus("setgroups");
924
ret = dup2(devnull, STDIN_FILENO);
926
perror_plus("dup2(devnull, STDIN_FILENO)");
929
ret = close(devnull);
931
perror_plus("close");
934
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
936
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
939
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
944
if(helperdir_fd == -1){
946
_exit(EX_UNAVAILABLE);
948
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
951
perror_plus("openat");
953
_exit(EX_UNAVAILABLE);
957
#pragma GCC diagnostic push
958
#pragma GCC diagnostic ignored "-Wcast-qual"
960
if(fexecve(helper_fd, (char *const [])
961
{ helper, add ? add_arg : delete_arg, (char *)address,
962
interface, debug ? debug_flag : NULL, NULL },
965
#pragma GCC diagnostic pop
967
perror_plus("fexecve");
979
pret = waitpid(pid, &status, 0);
980
if(pret == -1 and errno == EINTR and quit_now){
981
int errno_raising = 0;
982
if((errno = raise_privileges()) != 0){
983
errno_raising = errno;
984
perror_plus("Failed to raise privileges in order to"
985
" kill helper program");
987
if(kill(pid, SIGTERM) == -1){
990
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
991
perror_plus("Failed to lower privileges after killing"
996
} while(pret == -1 and errno == EINTR);
998
perror_plus("waitpid");
1001
if(WIFEXITED(status)){
1002
if(WEXITSTATUS(status) != 0){
1003
fprintf_plus(stderr, "Error: iprouteadddel exited"
1004
" with status %d\n", WEXITSTATUS(status));
1009
if(WIFSIGNALED(status)){
1010
fprintf_plus(stderr, "Error: iprouteadddel died by"
1011
" signal %d\n", WTERMSIG(status));
1014
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1018
__attribute__((nonnull, warn_unused_result))
1019
static bool add_local_route(const char *address,
1020
AvahiIfIndex if_index){
1022
fprintf_plus(stderr, "Adding route to %s\n", address);
1024
return add_delete_local_route(true, address, if_index);
1027
__attribute__((nonnull, warn_unused_result))
1028
static bool delete_local_route(const char *address,
1029
AvahiIfIndex if_index){
1031
fprintf_plus(stderr, "Removing route to %s\n", address);
1033
return add_delete_local_route(false, address, if_index);
642
1036
/* Called when a Mandos server is found */
643
1037
__attribute__((nonnull, warn_unused_result))
644
1038
static int start_mandos_communication(const char *ip, in_port_t port,
731
1126
goto mandos_end;
734
memset(&to, 0, sizeof(to));
735
1129
if(af == AF_INET6){
736
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
737
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
1130
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1131
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1132
ret = inet_pton(af, ip, &to6->sin6_addr);
738
1133
} else { /* IPv4 */
739
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
740
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
1134
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1135
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1136
ret = inet_pton(af, ip, &to4->sin_addr);
813
1209
goto mandos_end;
817
ret = connect(tcp_sd, (struct sockaddr *)&to,
818
sizeof(struct sockaddr_in6));
820
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
821
sizeof(struct sockaddr_in));
824
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
826
perror_plus("connect");
1214
ret = connect(tcp_sd, (struct sockaddr *)&to,
1215
sizeof(struct sockaddr_in6));
1217
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1218
sizeof(struct sockaddr_in));
1221
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1222
and if_index != AVAHI_IF_UNSPEC
1223
and connect_to == NULL
1224
and not route_added and
1225
((af == AF_INET6 and not
1226
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1228
or (af == AF_INET and
1229
/* Not a a IPv4LL address */
1230
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1231
& 0xFFFF0000L) != 0xA9FE0000L))){
1232
/* Work around Avahi bug - Avahi does not announce link-local
1233
addresses if it has a global address, so local hosts with
1234
*only* a link-local address (e.g. Mandos clients) cannot
1235
connect to a Mandos server announced by Avahi on a server
1236
host with a global address. Work around this by retrying
1237
with an explicit route added with the server's address.
1239
Avahi bug reference:
1240
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1241
https://bugs.debian.org/587961
1244
fprintf_plus(stderr, "Mandos server unreachable, trying"
1248
route_added = add_local_route(ip, if_index);
1254
if(errno != ECONNREFUSED or debug){
1256
perror_plus("connect");
837
1269
const char *out = mandos_protocol_version;
1453
/* Set effective uid to 0, return errno */
1454
__attribute__((warn_unused_result))
1455
error_t raise_privileges(void){
1456
error_t old_errno = errno;
1457
error_t ret_errno = 0;
1458
if(seteuid(0) == -1){
1460
perror_plus("seteuid");
1466
/* Set effective and real user ID to 0. Return errno. */
1467
__attribute__((warn_unused_result))
1468
error_t raise_privileges_permanently(void){
1469
error_t old_errno = errno;
1470
error_t ret_errno = raise_privileges();
1475
if(setuid(0) == -1){
1477
perror_plus("seteuid");
1483
/* Set effective user ID to unprivileged saved user ID */
1484
__attribute__((warn_unused_result))
1485
error_t lower_privileges(void){
1486
error_t old_errno = errno;
1487
error_t ret_errno = 0;
1488
if(seteuid(uid) == -1){
1490
perror_plus("seteuid");
1496
/* Lower privileges permanently */
1497
__attribute__((warn_unused_result))
1498
error_t lower_privileges_permanently(void){
1499
error_t old_errno = errno;
1500
error_t ret_errno = 0;
1501
if(setuid(uid) == -1){
1503
perror_plus("setuid");
1511
* Based on the example in the GNU LibC manual chapter 13.13 "File
1512
* Descriptor Flags".
1513
| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |
1515
__attribute__((warn_unused_result))
1516
static int set_cloexec_flag(int fd){
1517
int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));
1518
/* If reading the flags failed, return error indication now. */
1522
/* Store modified flag word in the descriptor. */
1523
return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,
1526
#endif /* not O_CLOEXEC */
1528
1893
__attribute__((nonnull))
1529
1894
void run_network_hooks(const char *mode, const char *interface,
1530
1895
const float delay){
1531
struct dirent **direntries;
1896
struct dirent **direntries = NULL;
1532
1897
if(hookdir_fd == -1){
1533
hookdir_fd = open(hookdir, O_RDONLY |
1536
#else /* not O_CLOEXEC */
1538
#endif /* not O_CLOEXEC */
1898
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1540
1900
if(hookdir_fd == -1){
1541
1901
if(errno == ENOENT){
1552
if(set_cloexec_flag(hookdir_fd) < 0){
1553
perror_plus("set_cloexec_flag");
1554
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1555
perror_plus("close");
1561
#endif /* not O_CLOEXEC */
1564
#if __GLIBC_PREREQ(2, 15)
1565
1912
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1566
1913
runnable_hook, alphasort);
1567
#else /* not __GLIBC_PREREQ(2, 15) */
1568
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1570
#endif /* not __GLIBC_PREREQ(2, 15) */
1571
#else /* not __GLIBC__ */
1572
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1574
#endif /* not __GLIBC__ */
1575
1914
if(numhooks == -1){
1576
1915
perror_plus("scandir");
1579
1918
struct dirent *direntry;
1581
int devnull = open("/dev/null", O_RDONLY);
1920
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1922
perror_plus("open(\"/dev/null\", O_RDONLY)");
1582
1925
for(int i = 0; i < numhooks; i++){
1583
1926
direntry = direntries[i];
1662
1991
_exit(EX_OSERR);
1665
if(fexecve(hookdir_fd, (char *const [])
1666
{ direntry->d_name, NULL }, environ) == -1){
1994
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
1998
perror_plus("openat");
1999
_exit(EXIT_FAILURE);
2001
if(close(hookdir_fd) == -1){
2002
perror_plus("close");
2003
_exit(EXIT_FAILURE);
2005
ret = dup2(devnull, STDIN_FILENO);
2007
perror_plus("dup2(devnull, STDIN_FILENO)");
2010
ret = close(devnull);
2012
perror_plus("close");
2015
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2017
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2020
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1667
2022
perror_plus("fexecve");
1668
2023
_exit(EXIT_FAILURE);
2027
perror_plus("fork");
1672
2032
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1673
2033
perror_plus("waitpid");
1676
2037
if(WIFEXITED(status)){
2614
3030
free(interfaces_to_take_down);
2615
3031
free(interfaces_hooks);
3033
void clean_dir_at(int base, const char * const dirname,
3035
struct dirent **direntries = NULL;
3037
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3043
perror_plus("open");
3045
int numentries = scandirat(dir_fd, ".", &direntries,
3046
notdotentries, alphasort);
3047
if(numentries >= 0){
3048
for(int i = 0; i < numentries; i++){
3050
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3051
dirname, direntries[i]->d_name);
3053
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3055
if(errno == EISDIR){
3056
dret = unlinkat(dir_fd, direntries[i]->d_name,
3059
if((dret == -1) and (errno == ENOTEMPTY)
3060
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3061
== 0) and (level == 0)){
3062
/* Recurse only in this special case */
3063
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3067
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3068
direntries[i]->d_name, strerror(errno));
3071
free(direntries[i]);
3074
/* need to clean even if 0 because man page doesn't specify */
3076
if(numentries == -1){
3077
perror_plus("scandirat");
3079
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3080
if(dret == -1 and errno != ENOENT){
3081
perror_plus("rmdir");
3084
perror_plus("scandirat");
2617
3089
/* Removes the GPGME temp directory and all files inside */
2618
3090
if(tempdir != NULL){
2619
struct dirent **direntries = NULL;
2620
struct dirent *direntry = NULL;
2621
int numentries = scandir(tempdir, &direntries, notdotentries,
2624
for(int i = 0; i < numentries; i++){
2625
direntry = direntries[i];
2626
char *fullname = NULL;
2627
ret = asprintf(&fullname, "%s/%s", tempdir,
2630
perror_plus("asprintf");
2633
ret = remove(fullname);
2635
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2642
/* need to clean even if 0 because man page doesn't specify */
2644
if(numentries == -1){
2645
perror_plus("scandir");
2647
ret = rmdir(tempdir);
2648
if(ret == -1 and errno != ENOENT){
2649
perror_plus("rmdir");
3091
clean_dir_at(-1, tempdir, 0);