575
569
safer_gnutls_strerror(ret));
578
if(mc->dh_bits == 0){
579
/* Find out the optimal number of DH bits */
580
/* Try to read the private key file */
581
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
583
int secfile = open(seckeyfilename, O_RDONLY);
584
size_t buffer_capacity = 0;
586
buffer_capacity = incbuffer((char **)&buffer.data,
588
(size_t)buffer_capacity);
589
if(buffer_capacity == 0){
590
perror_plus("incbuffer");
595
ssize_t bytes_read = read(secfile, buffer.data + buffer.size,
601
/* check bytes_read for failure */
608
buffer.size += (unsigned int)bytes_read;
612
/* If successful, use buffer to parse private key */
613
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
614
if(buffer.data != NULL){
616
gnutls_openpgp_privkey_t privkey = NULL;
617
ret = gnutls_openpgp_privkey_init(&privkey);
618
if(ret != GNUTLS_E_SUCCESS){
619
fprintf_plus(stderr, "Error initializing OpenPGP key"
620
" structure: %s", safer_gnutls_strerror(ret));
624
ret = gnutls_openpgp_privkey_import(privkey, &buffer,
625
GNUTLS_OPENPGP_FMT_BASE64,
627
if(ret != GNUTLS_E_SUCCESS){
628
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
629
safer_gnutls_strerror(ret));
635
/* Use private key to suggest an appropriate sec_param */
636
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
637
gnutls_openpgp_privkey_deinit(privkey);
639
fprintf_plus(stderr, "This OpenPGP key implies using a"
640
" GnuTLS security parameter \"%s\".\n",
641
safe_string(gnutls_sec_param_get_name
647
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
648
/* Err on the side of caution */
649
sec_param = GNUTLS_SEC_PARAM_ULTRA;
651
fprintf_plus(stderr, "Falling back to security parameter"
653
safe_string(gnutls_sec_param_get_name
658
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
662
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
663
" implies %u DH bits; using that.\n",
664
safe_string(gnutls_sec_param_get_name
669
fprintf_plus(stderr, "Failed to get implied number of DH"
670
" bits for security parameter \"%s\"): %s\n",
671
safe_string(gnutls_sec_param_get_name(sec_param)),
672
safer_gnutls_strerror(ret));
676
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
679
572
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
680
573
if(ret != GNUTLS_E_SUCCESS){
681
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"
682
" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));
574
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
575
safer_gnutls_strerror(ret));
757
650
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
758
651
__attribute__((unused)) const char *txt){}
653
/* Set effective uid to 0, return errno */
654
__attribute__((warn_unused_result))
655
error_t raise_privileges(void){
656
error_t old_errno = errno;
657
error_t ret_errno = 0;
658
if(seteuid(0) == -1){
665
/* Set effective and real user ID to 0. Return errno. */
666
__attribute__((warn_unused_result))
667
error_t raise_privileges_permanently(void){
668
error_t old_errno = errno;
669
error_t ret_errno = raise_privileges();
681
/* Set effective user ID to unprivileged saved user ID */
682
__attribute__((warn_unused_result))
683
error_t lower_privileges(void){
684
error_t old_errno = errno;
685
error_t ret_errno = 0;
686
if(seteuid(uid) == -1){
693
/* Lower privileges permanently */
694
__attribute__((warn_unused_result))
695
error_t lower_privileges_permanently(void){
696
error_t old_errno = errno;
697
error_t ret_errno = 0;
698
if(setuid(uid) == -1){
705
/* Helper function to add_local_route() and remove_local_route() */
706
__attribute__((nonnull, warn_unused_result))
707
static bool add_remove_local_route(const bool add,
709
AvahiIfIndex if_index){
711
char helper[] = "mandos-client-iprouteadddel";
712
char add_arg[] = "add";
713
char remove_arg[] = "remove";
714
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
715
if(pluginhelperdir == NULL){
717
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
718
" variable not set; cannot run helper\n");
723
char interface[IF_NAMESIZE];
724
if(if_indextoname((unsigned int)if_index, interface) == NULL){
725
perror_plus("if_indextoname");
729
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
731
perror_plus("open(\"/dev/null\", O_RDONLY)");
737
/* Raise privileges */
738
errno = raise_privileges_permanently();
740
perror_plus("Failed to raise privileges");
741
/* _exit(EX_NOPERM); */
747
perror_plus("setgid");
750
/* Reset supplementary groups */
752
ret = setgroups(0, NULL);
754
perror_plus("setgroups");
758
ret = dup2(devnull, STDIN_FILENO);
760
perror_plus("dup2(devnull, STDIN_FILENO)");
763
ret = (int)TEMP_FAILURE_RETRY(close(devnull));
765
perror_plus("close");
768
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
770
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
773
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
778
if(helperdir_fd == -1){
780
_exit(EX_UNAVAILABLE);
782
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
785
perror_plus("openat");
786
_exit(EX_UNAVAILABLE);
788
TEMP_FAILURE_RETRY(close(helperdir_fd));
790
#pragma GCC diagnostic push
791
#pragma GCC diagnostic ignored "-Wcast-qual"
793
if(fexecve(helper_fd, (char *const [])
794
{ helper, add ? add_arg : remove_arg, (char *)address,
795
interface, NULL }, environ) == -1){
797
#pragma GCC diagnostic pop
799
perror_plus("fexecve");
811
pret = waitpid(pid, &status, 0);
812
if(pret == -1 and errno == EINTR and quit_now){
813
int errno_raising = 0;
814
if((errno = raise_privileges()) != 0){
815
errno_raising = errno;
816
perror_plus("Failed to raise privileges in order to"
817
" kill helper program");
819
if(kill(pid, SIGTERM) == -1){
822
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
823
perror_plus("Failed to lower privileges after killing"
828
} while(pret == -1 and errno == EINTR);
830
perror_plus("waitpid");
833
if(WIFEXITED(status)){
834
if(WEXITSTATUS(status) != 0){
835
fprintf_plus(stderr, "Error: iprouteadddel exited"
836
" with status %d\n", WEXITSTATUS(status));
841
if(WIFSIGNALED(status)){
842
fprintf_plus(stderr, "Error: iprouteadddel died by"
843
" signal %d\n", WTERMSIG(status));
846
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
850
__attribute__((nonnull, warn_unused_result))
851
static bool add_local_route(const char *address,
852
AvahiIfIndex if_index){
853
return add_remove_local_route(true, address, if_index);
856
__attribute__((nonnull, warn_unused_result))
857
static bool remove_local_route(const char *address,
858
AvahiIfIndex if_index){
859
return add_remove_local_route(false, address, if_index);
760
862
/* Called when a Mandos server is found */
761
863
__attribute__((nonnull, warn_unused_result))
762
864
static int start_mandos_communication(const char *ip, in_port_t port,
931
1034
goto mandos_end;
935
ret = connect(tcp_sd, (struct sockaddr *)&to,
936
sizeof(struct sockaddr_in6));
938
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
939
sizeof(struct sockaddr_in));
942
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
944
perror_plus("connect");
1039
ret = connect(tcp_sd, (struct sockaddr *)&to,
1040
sizeof(struct sockaddr_in6));
1042
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1043
sizeof(struct sockaddr_in));
1046
if(errno == ENETUNREACH
1047
and if_index != AVAHI_IF_UNSPEC
1048
and connect_to == NULL
1049
and not route_added and
1050
((af == AF_INET6 and not
1051
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1053
or (af == AF_INET and
1054
/* Not a a IPv4LL address */
1055
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1056
& 0xFFFF0000L) != 0xA9FE0000L))){
1057
/* Work around Avahi bug - Avahi does not announce link-local
1058
addresses if it has a global address, so local hosts with
1059
*only* a link-local address (e.g. Mandos clients) cannot
1060
connect to a Mandos server announced by Avahi on a server
1061
host with a global address. Work around this by retrying
1062
with an explicit route added with the server's address.
1064
Avahi bug reference:
1065
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1066
https://bugs.debian.org/587961
1069
route_added = add_local_route(ip, if_index);
1075
if(errno != ECONNREFUSED or debug){
1077
perror_plus("connect");
955
1090
const char *out = mandos_protocol_version;
1572
/* Set effective uid to 0, return errno */
1573
__attribute__((warn_unused_result))
1574
error_t raise_privileges(void){
1575
error_t old_errno = errno;
1576
error_t ret_errno = 0;
1577
if(seteuid(0) == -1){
1584
/* Set effective and real user ID to 0. Return errno. */
1585
__attribute__((warn_unused_result))
1586
error_t raise_privileges_permanently(void){
1587
error_t old_errno = errno;
1588
error_t ret_errno = raise_privileges();
1593
if(setuid(0) == -1){
1600
/* Set effective user ID to unprivileged saved user ID */
1601
__attribute__((warn_unused_result))
1602
error_t lower_privileges(void){
1603
error_t old_errno = errno;
1604
error_t ret_errno = 0;
1605
if(seteuid(uid) == -1){
1612
/* Lower privileges permanently */
1613
__attribute__((warn_unused_result))
1614
error_t lower_privileges_permanently(void){
1615
error_t old_errno = errno;
1616
error_t ret_errno = 0;
1617
if(setuid(uid) == -1){
1624
1713
__attribute__((nonnull))
1625
1714
void run_network_hooks(const char *mode, const char *interface,
1626
1715
const float delay){
1627
1716
struct dirent **direntries = NULL;
1628
1717
if(hookdir_fd == -1){
1629
hookdir_fd = open(hookdir, O_RDONLY);
1718
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1630
1720
if(hookdir_fd == -1){
1631
1721
if(errno == ENOENT){