/mandos/release : revision 237.7.756

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* "browse_callback", and parts of "main".

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*

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* Everything else is

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*

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* This program is free software: you can redistribute it and/or

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* modify it under the terms of the GNU General Public License as

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* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

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* This program is distributed in the hope that it will be useful, but

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*

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* This file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* General Public License for more details.

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*

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* You should have received a copy of the GNU General Public License

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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*/

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/* Needed by GPGME, specifically gpgme_data_seek() */

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif

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#endif /* not _LARGEFILE_SOURCE */

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

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stdout, ferror(), remove() */

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#include <stdint.h> /* uint16_t, uint32_t */

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stdout, ferror() */

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#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

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strtof(), abort() */

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#include <stdbool.h> /* bool, false, true */

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#include <string.h> /* memset(), strcmp(), strlen(),

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strerror(), asprintf(), strcpy() */

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#include <string.h> /* strcmp(), strlen(), strerror(),

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asprintf(), strncpy(), strsignal()

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*/

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#include <sys/ioctl.h> /* ioctl */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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#include <sys/stat.h> /* open(), S_ISREG */

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#include <sys/socket.h> /* socket(), struct sockaddr_in6,

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inet_pton(), connect() */

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#include <fcntl.h> /* open() */

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inet_pton(), connect(),

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getnameinfo() */

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#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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*/

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#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

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strtoimax() */

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#include <assert.h> /* assert() */

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#include <errno.h> /* perror(), errno,

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#include <errno.h> /* perror(), errno, EINTR, EINVAL,

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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program_invocation_short_name */

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#include <time.h> /* nanosleep(), time(), sleep() */

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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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*/

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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), seteuid(),

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setgid(), pause() */

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#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */

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setgid(), pause(), _exit(),

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unlinkat() */

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#include <arpa/inet.h> /* inet_pton(), htons() */

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#include <iso646.h> /* not, or, and */

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#include <argp.h> /* struct argp_option, error_t, struct

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argp_state, struct argp,

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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#include <sys/wait.h> /* waitpid(), WIFEXITED(),

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WEXITSTATUS(), WTERMSIG() */

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#include <grp.h> /* setgroups() */

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#include <argz.h> /* argz_add_sep(), argz_next(),

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

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EAI_SYSTEM, gai_strerror() */

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#ifdef __linux__

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#include <sys/klog.h> /* klogctl() */

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gnutls_*

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init_gnutls_session(),

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GNUTLS_* */

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#if GNUTLS_VERSION_NUMBER < 0x030600

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#include <gnutls/openpgp.h>

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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#elif GNUTLS_VERSION_NUMBER >= 0x030606

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#include <gnutls/x509.h> /* gnutls_pkcs_encrypt_flags_t,

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GNUTLS_PKCS_PLAIN,

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GNUTLS_PKCS_NULL_PASSWORD */

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#endif

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/* GPGME */

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#include <gpgme.h> /* All GPGME types, constants and

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#define PATHDIR "/conf/conf.d/mandos"

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#define SECKEY "seckey.txt"

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#define PUBKEY "pubkey.txt"

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#define TLS_PRIVKEY "tls-privkey.pem"

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#define TLS_PUBKEY "tls-pubkey.pem"

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#define HOOKDIR "/lib/mandos/network-hooks.d"

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bool debug = false;

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static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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int hookdir_fd = -1;

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uid_t uid = 65534;

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gid_t gid = 65534;

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/* Doubly linked list that need to be circularly linked when used */

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typedef struct server{

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const char *ip;

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uint16_t port;

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in_port_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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/* Used for passing in values through the Avahi callback functions */

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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} mandos_context;

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/* global context so signal handler can reach it*/

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mandos_context mc = { .simple_poll = NULL, .server = NULL,

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.dh_bits = 1024, .priority = "SECURE256"

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":!CTYPE-X.509:+CTYPE-OPENPGP",

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.current_server = NULL };

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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/* Function to use when printing errors */

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void perror_plus(const char *print_text){

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int e = errno;

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fprintf(stderr, "Mandos plugin %s: ",

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program_invocation_short_name);

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errno = e;

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perror(print_text);

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}

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__attribute__((format (gnu_printf, 2, 3), nonnull))

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int fprintf_plus(FILE *stream, const char *format, ...){

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va_list ap;

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va_start (ap, format);

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TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

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program_invocation_short_name));

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return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

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return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

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}

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/*

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* bytes. "buffer_capacity" is how much is currently allocated,

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* "buffer_length" is how much is already used.

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*/

217

__attribute__((nonnull, warn_unused_result))

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size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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if(buffer_length + BUFFER_SIZE > buffer_capacity){

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*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

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if(buffer == NULL){

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char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

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if(new_buf == NULL){

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int old_errno = errno;

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free(*buffer);

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errno = old_errno;

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*buffer = NULL;

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return 0;

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}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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231

}

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return buffer_capacity;

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}

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/* Add server to set of servers to retry periodically */

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int add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

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int af){

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__attribute__((nonnull, warn_unused_result))

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bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

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int af, server **current_server){

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int ret;

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server *new_server = malloc(sizeof(server));

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if(new_server == NULL){

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perror_plus("malloc");

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return -1;

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return false;

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}

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*new_server = (server){ .ip = strdup(ip),

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.port = port,

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.af = af };

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if(new_server->ip == NULL){

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perror_plus("strdup");

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return -1;

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free(new_server);

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return false;

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}

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ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

255

if(ret == -1){

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perror_plus("clock_gettime");

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#ifdef __GNUC__

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#pragma GCC diagnostic push

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#pragma GCC diagnostic ignored "-Wcast-qual"

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#endif

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free((char *)(new_server->ip));

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#ifdef __GNUC__

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#pragma GCC diagnostic pop

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#endif

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free(new_server);

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return false;

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}

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/* Special case of first server */

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if (mc.current_server == NULL){

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if(*current_server == NULL){

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new_server->next = new_server;

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new_server->prev = new_server;

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mc.current_server = new_server;

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/* Place the new server last in the list */

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*current_server = new_server;

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} else {

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new_server->next = mc.current_server;

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new_server->prev = mc.current_server->prev;

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/* Place the new server last in the list */

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new_server->next = *current_server;

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new_server->prev = (*current_server)->prev;

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new_server->prev->next = new_server;

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mc.current_server->prev = new_server;

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}

232

ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

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if(ret == -1){

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perror_plus("clock_gettime");

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return -1;

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}

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return 0;

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(*current_server)->prev = new_server;

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}

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return true;

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}

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/* Set effective uid to 0, return errno */

284

__attribute__((warn_unused_result))

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int raise_privileges(void){

286

int old_errno = errno;

287

int ret = 0;

288

if(seteuid(0) == -1){

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ret = errno;

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}

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errno = old_errno;

292

return ret;

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}

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/* Set effective and real user ID to 0. Return errno. */

296

__attribute__((warn_unused_result))

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int raise_privileges_permanently(void){

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int old_errno = errno;

299

int ret = raise_privileges();

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if(ret != 0){

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errno = old_errno;

302

return ret;

303

}

304

if(setuid(0) == -1){

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ret = errno;

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}

307

errno = old_errno;

308

return ret;

309

}

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/* Set effective user ID to unprivileged saved user ID */

312

__attribute__((warn_unused_result))

313

int lower_privileges(void){

314

int old_errno = errno;

315

int ret = 0;

316

if(seteuid(uid) == -1){

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ret = errno;

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}

319

errno = old_errno;

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return ret;

321

}

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/* Lower privileges permanently */

324

__attribute__((warn_unused_result))

325

int lower_privileges_permanently(void){

326

int old_errno = errno;

327

int ret = 0;

328

if(setuid(uid) == -1){

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ret = errno;

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}

331

errno = old_errno;

332

return ret;

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}

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/*

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* Initialize GPGME.

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337

*/

243

static bool init_gpgme(const char *seckey, const char *pubkey,

244

const char *tempdir){

338

__attribute__((nonnull, warn_unused_result))

339

static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

341

const char * const tempdir,

342

mandos_context *mc){

245

343

gpgme_error_t rc;

246

344

gpgme_engine_info_t engine_info;

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345

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/*

250

347

* Helper function to insert pub and seckey to the engine keyring.

251

348

*/

252

bool import_key(const char *filename){

349

bool import_key(const char * const filename){

253

350

int ret;

254

351

int fd;

255

352

gpgme_data_t pgp_data;

260

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return false;

261

358

}

262

359

360

/* Workaround for systems without a real-time clock; see also

361

Debian bug #894495: <https://bugs.debian.org/894495> */

362

do {

363

{

364

time_t currtime = time(NULL);

365

if(currtime != (time_t)-1){

366

struct tm tm;

367

if(gmtime_r(&currtime, &tm) == NULL) {

368

perror_plus("gmtime_r");

369

break;

370

}

371

if(tm.tm_year != 70 or tm.tm_mon != 0){

372

break;

373

}

374

if(debug){

375

fprintf_plus(stderr, "System clock is January 1970");

376

}

377

} else {

378

if(debug){

379

fprintf_plus(stderr, "System clock is invalid");

380

}

381

}

382

}

383

struct stat keystat;

384

ret = fstat(fd, &keystat);

385

if(ret != 0){

386

perror_plus("fstat");

387

break;

388

}

389

ret = raise_privileges();

390

if(ret != 0){

391

errno = ret;

392

perror_plus("Failed to raise privileges");

393

break;

394

}

395

if(debug){

396

fprintf_plus(stderr,

397

"Setting system clock to key file mtime");

398

}

399

time_t keytime = keystat.st_mtim.tv_sec;

400

if(stime(&keytime) != 0){

401

perror_plus("stime");

402

}

403

ret = lower_privileges();

404

if(ret != 0){

405

errno = ret;

406

perror_plus("Failed to lower privileges");

407

}

408

} while(false);

409

263

410

rc = gpgme_data_new_from_fd(&pgp_data, fd);

264

411

if(rc != GPG_ERR_NO_ERROR){

265

412

fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

267

414

return false;

268

415

}

269

416

270

rc = gpgme_op_import(mc.ctx, pgp_data);

417

rc = gpgme_op_import(mc->ctx, pgp_data);

271

418

if(rc != GPG_ERR_NO_ERROR){

272

419

fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",

273

420

gpgme_strsource(rc), gpgme_strerror(rc));

274

421

return false;

275

422

}

423

{

424

gpgme_import_result_t import_result

425

= gpgme_op_import_result(mc->ctx);

426

if((import_result->imported < 1

427

or import_result->not_imported > 0)

428

and import_result->unchanged == 0){

429

fprintf_plus(stderr, "bad gpgme_op_import_results:\n");

430

fprintf_plus(stderr,

431

"The total number of considered keys: %d\n",

432

import_result->considered);

433

fprintf_plus(stderr,

434

"The number of keys without user ID: %d\n",

435

import_result->no_user_id);

436

fprintf_plus(stderr,

437

"The total number of imported keys: %d\n",

438

import_result->imported);

439

fprintf_plus(stderr, "The number of imported RSA keys: %d\n",

440

import_result->imported_rsa);

441

fprintf_plus(stderr, "The number of unchanged keys: %d\n",

442

import_result->unchanged);

443

fprintf_plus(stderr, "The number of new user IDs: %d\n",

444

import_result->new_user_ids);

445

fprintf_plus(stderr, "The number of new sub keys: %d\n",

446

import_result->new_sub_keys);

447

fprintf_plus(stderr, "The number of new signatures: %d\n",

448

import_result->new_signatures);

449

fprintf_plus(stderr, "The number of new revocations: %d\n",

450

import_result->new_revocations);

451

fprintf_plus(stderr,

452

"The total number of secret keys read: %d\n",

453

import_result->secret_read);

454

fprintf_plus(stderr,

455

"The number of imported secret keys: %d\n",

456

import_result->secret_imported);

457

fprintf_plus(stderr,

458

"The number of unchanged secret keys: %d\n",

459

import_result->secret_unchanged);

460

fprintf_plus(stderr, "The number of keys not imported: %d\n",

461

import_result->not_imported);

462

for(gpgme_import_status_t import_status

463

= import_result->imports;

464

import_status != NULL;

465

import_status = import_status->next){

466

fprintf_plus(stderr, "Import status for key: %s\n",

467

import_status->fpr);

468

if(import_status->result != GPG_ERR_NO_ERROR){

469

fprintf_plus(stderr, "Import result: %s: %s\n",

470

gpgme_strsource(import_status->result),

471

gpgme_strerror(import_status->result));

472

}

473

fprintf_plus(stderr, "Key status:\n");

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_NEW

476

? "The key was new.\n"

477

: "The key was not new.\n");

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_UID

480

? "The key contained new user IDs.\n"

481

: "The key did not contain new user IDs.\n");

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SIG

484

? "The key contained new signatures.\n"

485

: "The key did not contain new signatures.\n");

486

fprintf_plus(stderr,

487

import_status->status & GPGME_IMPORT_SUBKEY

488

? "The key contained new sub keys.\n"

489

: "The key did not contain new sub keys.\n");

490

fprintf_plus(stderr,

491

import_status->status & GPGME_IMPORT_SECRET

492

? "The key contained a secret key.\n"

493

: "The key did not contain a secret key.\n");

494

}

495

return false;

496

}

497

}

276

498

277

ret = (int)TEMP_FAILURE_RETRY(close(fd));

499

ret = close(fd);

278

500

if(ret == -1){

279

501

perror_plus("close");

280

502

}

317

539

}

318

540

319

541

/* Create new GPGME "context" */

320

rc = gpgme_new(&(mc.ctx));

542

rc = gpgme_new(&(mc->ctx));

321

543

if(rc != GPG_ERR_NO_ERROR){

322

fprintf_plus(stderr, "Mandos plugin mandos-client: "

323

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

324

gpgme_strerror(rc));

544

fprintf_plus(stderr, "bad gpgme_new: %s: %s\n",

545

gpgme_strsource(rc), gpgme_strerror(rc));

325

546

return false;

326

547

}

327

548

336

557

* Decrypt OpenPGP data.

337

558

* Returns -1 on error

338

559

*/

560

__attribute__((nonnull, warn_unused_result))

339

561

static ssize_t pgp_packet_decrypt(const char *cryptotext,

340

562

size_t crypto_size,

341

char **plaintext){

563

char **plaintext,

564

mandos_context *mc){

342

565

gpgme_data_t dh_crypto, dh_plain;

343

566

gpgme_error_t rc;

344

567

ssize_t ret;

361

584

/* Create new empty GPGME data buffer for the plaintext */

362

585

rc = gpgme_data_new(&dh_plain);

363

586

if(rc != GPG_ERR_NO_ERROR){

364

fprintf_plus(stderr, "Mandos plugin mandos-client: "

365

"bad gpgme_data_new: %s: %s\n",

587

fprintf_plus(stderr, "bad gpgme_data_new: %s: %s\n",

366

588

gpgme_strsource(rc), gpgme_strerror(rc));

367

589

gpgme_data_release(dh_crypto);

368

590

return -1;

370

592

371

593

/* Decrypt data from the cryptotext data buffer to the plaintext

372

594

data buffer */

373

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

595

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

374

596

if(rc != GPG_ERR_NO_ERROR){

375

597

fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",

376

598

gpgme_strsource(rc), gpgme_strerror(rc));

377

599

plaintext_length = -1;

378

600

if(debug){

379

601

gpgme_decrypt_result_t result;

380

result = gpgme_op_decrypt_result(mc.ctx);

602

result = gpgme_op_decrypt_result(mc->ctx);

381

603

if(result == NULL){

382

604

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

383

605

} else {

384

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

385

result->unsupported_algorithm);

386

fprintf_plus(stderr, "Wrong key usage: %u\n",

387

result->wrong_key_usage);

606

if(result->unsupported_algorithm != NULL) {

607

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

608

result->unsupported_algorithm);

609

}

610

fprintf_plus(stderr, "Wrong key usage: %s\n",

611

result->wrong_key_usage ? "Yes" : "No");

388

612

if(result->file_name != NULL){

389

613

fprintf_plus(stderr, "File name: %s\n", result->file_name);

390

614

}

391

gpgme_recipient_t recipient;

392

recipient = result->recipients;

393

while(recipient != NULL){

615

616

for(gpgme_recipient_t r = result->recipients; r != NULL;

617

r = r->next){

394

618

fprintf_plus(stderr, "Public key algorithm: %s\n",

395

gpgme_pubkey_algo_name

396

(recipient->pubkey_algo));

397

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

619

gpgme_pubkey_algo_name(r->pubkey_algo));

620

fprintf_plus(stderr, "Key ID: %s\n", r->keyid);

398

621

fprintf_plus(stderr, "Secret key available: %s\n",

399

recipient->status == GPG_ERR_NO_SECKEY

400

? "No" : "Yes");

401

recipient = recipient->next;

622

r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");

402

623

}

403

624

}

404

625

}

460

681

return plaintext_length;

461

682

}

462

683

463

static const char * safer_gnutls_strerror(int value){

464

const char *ret = gnutls_strerror(value); /* Spurious warning from

465

-Wunreachable-code */

466

if(ret == NULL)

467

ret = "(unknown)";

468

return ret;

684

__attribute__((warn_unused_result, const))

685

static const char *safe_string(const char *str){

686

if(str == NULL)

687

return "(unknown)";

688

return str;

689

}

690

691

__attribute__((warn_unused_result))

692

static const char *safer_gnutls_strerror(int value){

693

const char *ret = gnutls_strerror(value);

694

return safe_string(ret);

469

695

}

470

696

471

697

/* GnuTLS log function callback */

698

__attribute__((nonnull))

472

699

static void debuggnutls(__attribute__((unused)) int level,

473

700

const char* string){

474

701

fprintf_plus(stderr, "GnuTLS: %s", string);

475

702

}

476

703

704

__attribute__((nonnull(1, 2, 4), warn_unused_result))

477

705

static int init_gnutls_global(const char *pubkeyfilename,

478

const char *seckeyfilename){

706

const char *seckeyfilename,

707

const char *dhparamsfilename,

708

mandos_context *mc){

479

709

int ret;

480

710

481

711

if(debug){

482

712

fprintf_plus(stderr, "Initializing GnuTLS\n");

483

713

}

484

714

485

ret = gnutls_global_init();

486

if(ret != GNUTLS_E_SUCCESS){

487

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

488

safer_gnutls_strerror(ret));

489

return -1;

490

}

491

492

715

if(debug){

493

716

/* "Use a log level over 10 to enable all debugging options."

494

717

* - GnuTLS manual

498

721

}

499

722

500

723

/* OpenPGP credentials */

501

ret = gnutls_certificate_allocate_credentials(&mc.cred);

724

ret = gnutls_certificate_allocate_credentials(&mc->cred);

502

725

if(ret != GNUTLS_E_SUCCESS){

503

726

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

504

727

safer_gnutls_strerror(ret));

505

gnutls_global_deinit();

506

728

return -1;

507

729

}

508

730

509

731

if(debug){

510

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

511

" secret key %s as GnuTLS credentials\n",

732

fprintf_plus(stderr, "Attempting to use public key %s and"

733

" private key %s as GnuTLS credentials\n",

512

734

pubkeyfilename,

513

735

seckeyfilename);

514

736

}

515

737

738

#if GNUTLS_VERSION_NUMBER >= 0x030606

739

ret = gnutls_certificate_set_rawpk_key_file

740

(mc->cred, pubkeyfilename, seckeyfilename,

741

GNUTLS_X509_FMT_PEM, /* format */

742

NULL, /* pass */

743

/* key_usage */

744

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

745

NULL, /* names */

746

0, /* names_length */

747

/* privkey_flags */

748

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

749

0); /* pkcs11_flags */

750

#elif GNUTLS_VERSION_NUMBER < 0x030600

516

751

ret = gnutls_certificate_set_openpgp_key_file

517

(mc.cred, pubkeyfilename, seckeyfilename,

752

(mc->cred, pubkeyfilename, seckeyfilename,

518

753

GNUTLS_OPENPGP_FMT_BASE64);

754

#else

755

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

756

#endif

519

757

if(ret != GNUTLS_E_SUCCESS){

520

758

fprintf_plus(stderr,

521

"Error[%d] while reading the OpenPGP key pair ('%s',"

759

"Error[%d] while reading the key pair ('%s',"

522

760

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

523

761

fprintf_plus(stderr, "The GnuTLS error is: %s\n",

524

762

safer_gnutls_strerror(ret));

526

764

}

527

765

528

766

/* GnuTLS server initialization */

529

ret = gnutls_dh_params_init(&mc.dh_params);

767

ret = gnutls_dh_params_init(&mc->dh_params);

530

768

if(ret != GNUTLS_E_SUCCESS){

531

769

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

532

770

" initialization: %s\n",

533

771

safer_gnutls_strerror(ret));

534

772

goto globalfail;

535

773

}

536

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

537

if(ret != GNUTLS_E_SUCCESS){

538

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

539

safer_gnutls_strerror(ret));

540

goto globalfail;

541

}

542

543

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

774

/* If a Diffie-Hellman parameters file was given, try to use it */

775

if(dhparamsfilename != NULL){

776

gnutls_datum_t params = { .data = NULL, .size = 0 };

777

do {

778

int dhpfile = open(dhparamsfilename, O_RDONLY);

779

if(dhpfile == -1){

780

perror_plus("open");

781

dhparamsfilename = NULL;

782

break;

783

}

784

size_t params_capacity = 0;

785

while(true){

786

params_capacity = incbuffer((char **)&params.data,

787

(size_t)params.size,

788

(size_t)params_capacity);

789

if(params_capacity == 0){

790

perror_plus("incbuffer");

791

free(params.data);

792

params.data = NULL;

793

dhparamsfilename = NULL;

794

break;

795

}

796

ssize_t bytes_read = read(dhpfile,

797

params.data + params.size,

798

BUFFER_SIZE);

799

/* EOF */

800

if(bytes_read == 0){

801

break;

802

}

803

/* check bytes_read for failure */

804

if(bytes_read < 0){

805

perror_plus("read");

806

free(params.data);

807

params.data = NULL;

808

dhparamsfilename = NULL;

809

break;

810

}

811

params.size += (unsigned int)bytes_read;

812

}

813

ret = close(dhpfile);

814

if(ret == -1){

815

perror_plus("close");

816

}

817

if(params.data == NULL){

818

dhparamsfilename = NULL;

819

}

820

if(dhparamsfilename == NULL){

821

break;

822

}

823

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

824

GNUTLS_X509_FMT_PEM);

825

if(ret != GNUTLS_E_SUCCESS){

826

fprintf_plus(stderr, "Failed to parse DH parameters in file"

827

" \"%s\": %s\n", dhparamsfilename,

828

safer_gnutls_strerror(ret));

829

dhparamsfilename = NULL;

830

}

831

free(params.data);

832

} while(false);

833

}

834

if(dhparamsfilename == NULL){

835

if(mc->dh_bits == 0){

836

#if GNUTLS_VERSION_NUMBER < 0x030600

837

/* Find out the optimal number of DH bits */

838

/* Try to read the private key file */

839

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

840

do {

841

int secfile = open(seckeyfilename, O_RDONLY);

842

if(secfile == -1){

843

perror_plus("open");

844

break;

845

}

846

size_t buffer_capacity = 0;

847

while(true){

848

buffer_capacity = incbuffer((char **)&buffer.data,

849

(size_t)buffer.size,

850

(size_t)buffer_capacity);

851

if(buffer_capacity == 0){

852

perror_plus("incbuffer");

853

free(buffer.data);

854

buffer.data = NULL;

855

break;

856

}

857

ssize_t bytes_read = read(secfile,

858

buffer.data + buffer.size,

859

BUFFER_SIZE);

860

/* EOF */

861

if(bytes_read == 0){

862

break;

863

}

864

/* check bytes_read for failure */

865

if(bytes_read < 0){

866

perror_plus("read");

867

free(buffer.data);

868

buffer.data = NULL;

869

break;

870

}

871

buffer.size += (unsigned int)bytes_read;

872

}

873

close(secfile);

874

} while(false);

875

/* If successful, use buffer to parse private key */

876

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

877

if(buffer.data != NULL){

878

{

879

gnutls_openpgp_privkey_t privkey = NULL;

880

ret = gnutls_openpgp_privkey_init(&privkey);

881

if(ret != GNUTLS_E_SUCCESS){

882

fprintf_plus(stderr, "Error initializing OpenPGP key"

883

" structure: %s",

884

safer_gnutls_strerror(ret));

885

free(buffer.data);

886

buffer.data = NULL;

887

} else {

888

ret = gnutls_openpgp_privkey_import

889

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

890

if(ret != GNUTLS_E_SUCCESS){

891

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

892

safer_gnutls_strerror(ret));

893

privkey = NULL;

894

}

895

free(buffer.data);

896

buffer.data = NULL;

897

if(privkey != NULL){

898

/* Use private key to suggest an appropriate

899

sec_param */

900

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

901

gnutls_openpgp_privkey_deinit(privkey);

902

if(debug){

903

fprintf_plus(stderr, "This OpenPGP key implies using"

904

" a GnuTLS security parameter \"%s\".\n",

905

safe_string(gnutls_sec_param_get_name

906

(sec_param)));

907

}

908

}

909

}

910

}

911

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

912

/* Err on the side of caution */

913

sec_param = GNUTLS_SEC_PARAM_ULTRA;

914

if(debug){

915

fprintf_plus(stderr, "Falling back to security parameter"

916

" \"%s\"\n",

917

safe_string(gnutls_sec_param_get_name

918

(sec_param)));

919

}

920

}

921

}

922

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

923

if(uret != 0){

924

mc->dh_bits = uret;

925

if(debug){

926

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

927

" implies %u DH bits; using that.\n",

928

safe_string(gnutls_sec_param_get_name

929

(sec_param)),

930

mc->dh_bits);

931

}

932

} else {

933

fprintf_plus(stderr, "Failed to get implied number of DH"

934

" bits for security parameter \"%s\"): %s\n",

935

safe_string(gnutls_sec_param_get_name

936

(sec_param)),

937

safer_gnutls_strerror(ret));

938

goto globalfail;

939

}

940

#endif

941

} else { /* dh_bits != 0 */

942

if(debug){

943

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

944

mc->dh_bits);

945

}

946

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

947

if(ret != GNUTLS_E_SUCCESS){

948

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

949

" bits): %s\n", mc->dh_bits,

950

safer_gnutls_strerror(ret));

951

goto globalfail;

952

}

953

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

954

}

955

}

544

956

545

957

return 0;

546

958

547

959

globalfail:

548

960

549

gnutls_certificate_free_credentials(mc.cred);

550

gnutls_global_deinit();

551

gnutls_dh_params_deinit(mc.dh_params);

961

gnutls_certificate_free_credentials(mc->cred);

962

gnutls_dh_params_deinit(mc->dh_params);

552

963

return -1;

553

964

}

554

965

555

static int init_gnutls_session(gnutls_session_t *session){

966

__attribute__((nonnull, warn_unused_result))

967

static int init_gnutls_session(gnutls_session_t *session,

968

mandos_context *mc){

556

969

int ret;

557

970

/* GnuTLS session creation */

558

971

do {

559

ret = gnutls_init(session, GNUTLS_SERVER);

972

ret = gnutls_init(session, (GNUTLS_SERVER

973

#if GNUTLS_VERSION_NUMBER >= 0x030506

974

| GNUTLS_NO_TICKETS

975

#endif

976

#if GNUTLS_VERSION_NUMBER >= 0x030606

977

| GNUTLS_ENABLE_RAWPK

978

#endif

979

));

560

980

if(quit_now){

561

981

return -1;

562

982

}

570

990

{

571

991

const char *err;

572

992

do {

573

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

993

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

574

994

if(quit_now){

575

995

gnutls_deinit(*session);

576

996

return -1;

587

1007

588

1008

do {

589

1009

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

590

mc.cred);

1010

mc->cred);

591

1011

if(quit_now){

592

1012

gnutls_deinit(*session);

593

1013

return -1;

603

1023

/* ignore client certificate if any. */

604

1024

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

605

1025

606

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

607

608

1026

return 0;

609

1027

}

610

1028

612

1030

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

613

1031

__attribute__((unused)) const char *txt){}

614

1032

1033

/* Helper function to add_local_route() and delete_local_route() */

1034

__attribute__((nonnull, warn_unused_result))

1035

static bool add_delete_local_route(const bool add,

1036

const char *address,

1037

AvahiIfIndex if_index){

1038

int ret;

1039

char helper[] = "mandos-client-iprouteadddel";

1040

char add_arg[] = "add";

1041

char delete_arg[] = "delete";

1042

char debug_flag[] = "--debug";

1043

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1044

if(pluginhelperdir == NULL){

1045

if(debug){

1046

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1047

" variable not set; cannot run helper\n");

1048

}

1049

return false;

1050

}

1051

1052

char interface[IF_NAMESIZE];

1053

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1054

perror_plus("if_indextoname");

1055

return false;

1056

}

1057

1058

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1059

if(devnull == -1){

1060

perror_plus("open(\"/dev/null\", O_RDONLY)");

1061

return false;

1062

}

1063

pid_t pid = fork();

1064

if(pid == 0){

1065

/* Child */

1066

/* Raise privileges */

1067

errno = raise_privileges_permanently();

1068

if(errno != 0){

1069

perror_plus("Failed to raise privileges");

1070

/* _exit(EX_NOPERM); */

1071

} else {

1072

/* Set group */

1073

errno = 0;

1074

ret = setgid(0);

1075

if(ret == -1){

1076

perror_plus("setgid");

1077

_exit(EX_NOPERM);

1078

}

1079

/* Reset supplementary groups */

1080

errno = 0;

1081

ret = setgroups(0, NULL);

1082

if(ret == -1){

1083

perror_plus("setgroups");

1084

_exit(EX_NOPERM);

1085

}

1086

}

1087

ret = dup2(devnull, STDIN_FILENO);

1088

if(ret == -1){

1089

perror_plus("dup2(devnull, STDIN_FILENO)");

1090

_exit(EX_OSERR);

1091

}

1092

ret = close(devnull);

1093

if(ret == -1){

1094

perror_plus("close");

1095

_exit(EX_OSERR);

1096

}

1097

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1098

if(ret == -1){

1099

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1100

_exit(EX_OSERR);

1101

}

1102

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

1103

O_RDONLY

1104

| O_DIRECTORY

1105

| O_PATH

1106

| O_CLOEXEC));

1107

if(helperdir_fd == -1){

1108

perror_plus("open");

1109

_exit(EX_UNAVAILABLE);

1110

}

1111

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

1112

helper, O_RDONLY));

1113

if(helper_fd == -1){

1114

perror_plus("openat");

1115

close(helperdir_fd);

1116

_exit(EX_UNAVAILABLE);

1117

}

1118

close(helperdir_fd);

1119

#ifdef __GNUC__

1120

#pragma GCC diagnostic push

1121

#pragma GCC diagnostic ignored "-Wcast-qual"

1122

#endif

1123

if(fexecve(helper_fd, (char *const [])

1124

{ helper, add ? add_arg : delete_arg, (char *)address,

1125

interface, debug ? debug_flag : NULL, NULL },

1126

environ) == -1){

1127

#ifdef __GNUC__

1128

#pragma GCC diagnostic pop

1129

#endif

1130

perror_plus("fexecve");

1131

_exit(EXIT_FAILURE);

1132

}

1133

}

1134

if(pid == -1){

1135

perror_plus("fork");

1136

return false;

1137

}

1138

int status;

1139

pid_t pret = -1;

1140

errno = 0;

1141

do {

1142

pret = waitpid(pid, &status, 0);

1143

if(pret == -1 and errno == EINTR and quit_now){

1144

int errno_raising = 0;

1145

if((errno = raise_privileges()) != 0){

1146

errno_raising = errno;

1147

perror_plus("Failed to raise privileges in order to"

1148

" kill helper program");

1149

}

1150

if(kill(pid, SIGTERM) == -1){

1151

perror_plus("kill");

1152

}

1153

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

1154

perror_plus("Failed to lower privileges after killing"

1155

" helper program");

1156

}

1157

return false;

1158

}

1159

} while(pret == -1 and errno == EINTR);

1160

if(pret == -1){

1161

perror_plus("waitpid");

1162

return false;

1163

}

1164

if(WIFEXITED(status)){

1165

if(WEXITSTATUS(status) != 0){

1166

fprintf_plus(stderr, "Error: iprouteadddel exited"

1167

" with status %d\n", WEXITSTATUS(status));

1168

return false;

1169

}

1170

return true;

1171

}

1172

if(WIFSIGNALED(status)){

1173

fprintf_plus(stderr, "Error: iprouteadddel died by"

1174

" signal %d\n", WTERMSIG(status));

1175

return false;

1176

}

1177

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1178

return false;

1179

}

1180

1181

__attribute__((nonnull, warn_unused_result))

1182

static bool add_local_route(const char *address,

1183

AvahiIfIndex if_index){

1184

if(debug){

1185

fprintf_plus(stderr, "Adding route to %s\n", address);

1186

}

1187

return add_delete_local_route(true, address, if_index);

1188

}

1189

1190

__attribute__((nonnull, warn_unused_result))

1191

static bool delete_local_route(const char *address,

1192

AvahiIfIndex if_index){

1193

if(debug){

1194

fprintf_plus(stderr, "Removing route to %s\n", address);

1195

}

1196

return add_delete_local_route(false, address, if_index);

1197

}

1198

615

1199

/* Called when a Mandos server is found */

616

static int start_mandos_communication(const char *ip, uint16_t port,

1200

__attribute__((nonnull, warn_unused_result))

1201

static int start_mandos_communication(const char *ip, in_port_t port,

617

1202

AvahiIfIndex if_index,

618

int af){

1203

int af, mandos_context *mc){

619

1204

int ret, tcp_sd = -1;

620

1205

ssize_t sret;

621

union {

622

struct sockaddr_in in;

623

struct sockaddr_in6 in6;

624

} to;

1206

struct sockaddr_storage to;

625

1207

char *buffer = NULL;

626

1208

char *decrypted_buffer = NULL;

627

1209

size_t buffer_length = 0;

630

1212

int retval = -1;

631

1213

gnutls_session_t session;

632

1214

int pf; /* Protocol family */

1215

bool route_added = false;

633

1216

634

1217

errno = 0;

635

1218

651

1234

return -1;

652

1235

}

653

1236

654

ret = init_gnutls_session(&session);

1237

/* If the interface is specified and we have a list of interfaces */

1238

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1239

/* Check if the interface is one of the interfaces we are using */

1240

bool match = false;

1241

{

1242

char *interface = NULL;

1243

while((interface = argz_next(mc->interfaces,

1244

mc->interfaces_size,

1245

interface))){

1246

if(if_nametoindex(interface) == (unsigned int)if_index){

1247

match = true;

1248

break;

1249

}

1250

}

1251

}

1252

if(not match){

1253

/* This interface does not match any in the list, so we don't

1254

connect to the server */

1255

if(debug){

1256

char interface[IF_NAMESIZE];

1257

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1258

perror_plus("if_indextoname");

1259

} else {

1260

fprintf_plus(stderr, "Skipping server on non-used interface"

1261

" \"%s\"\n",

1262

if_indextoname((unsigned int)if_index,

1263

interface));

1264

}

1265

}

1266

return -1;

1267

}

1268

}

1269

1270

ret = init_gnutls_session(&session, mc);

655

1271

if(ret != 0){

656

1272

return -1;

657

1273

}

658

1274

659

1275

if(debug){

660

1276

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

661

PRIu16 "\n", ip, port);

1277

PRIuMAX "\n", ip, (uintmax_t)port);

662

1278

}

663

1279

664

tcp_sd = socket(pf, SOCK_STREAM, 0);

1280

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

665

1281

if(tcp_sd < 0){

666

1282

int e = errno;

667

1283

perror_plus("socket");

674

1290

goto mandos_end;

675

1291

}

676

1292

677

memset(&to, 0, sizeof(to));

678

1293

if(af == AF_INET6){

679

to.in6.sin6_family = (sa_family_t)af;

680

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1294

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1295

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1296

ret = inet_pton(af, ip, &to6->sin6_addr);

681

1297

} else { /* IPv4 */

682

to.in.sin_family = (sa_family_t)af;

683

ret = inet_pton(af, ip, &to.in.sin_addr);

1298

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1299

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1300

ret = inet_pton(af, ip, &to4->sin_addr);

684

1301

}

685

1302

if(ret < 0 ){

686

1303

int e = errno;

695

1312

goto mandos_end;

696

1313

}

697

1314

if(af == AF_INET6){

698

to.in6.sin6_port = htons(port); /* Spurious warnings from

699

-Wconversion and

700

-Wunreachable-code */

701

702

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

703

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

704

-Wunreachable-code*/

1315

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1316

if(IN6_IS_ADDR_LINKLOCAL

1317

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

705

1318

if(if_index == AVAHI_IF_UNSPEC){

706

1319

fprintf_plus(stderr, "An IPv6 link-local address is"

707

1320

" incomplete without a network interface\n");

709

1322

goto mandos_end;

710

1323

}

711

1324

/* Set the network interface number as scope */

712

to.in6.sin6_scope_id = (uint32_t)if_index;

1325

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

713

1326

}

714

1327

} else {

715

to.in.sin_port = htons(port); /* Spurious warnings from

716

-Wconversion and

717

-Wunreachable-code */

1328

((struct sockaddr_in *)&to)->sin_port = htons(port);

718

1329

}

719

1330

720

1331

if(quit_now){

728

1339

if(if_indextoname((unsigned int)if_index, interface) == NULL){

729

1340

perror_plus("if_indextoname");

730

1341

} else {

731

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

732

"\n", ip, interface, port);

1342

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1343

"\n", ip, interface, (uintmax_t)port);

733

1344

}

734

1345

} else {

735

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

736

ip, port);

1346

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1347

ip, (uintmax_t)port);

737

1348

}

738

1349

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

739

1350

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

740

const char *pcret;

741

if(af == AF_INET6){

742

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

743

sizeof(addrstr));

744

} else {

745

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

746

sizeof(addrstr));

747

}

748

if(pcret == NULL){

749

perror_plus("inet_ntop");

750

} else {

751

if(strcmp(addrstr, ip) != 0){

752

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

753

}

754

}

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

760

}

761

762

if(af == AF_INET6){

763

ret = connect(tcp_sd, &to.in6, sizeof(to));

764

} else {

765

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

766

}

767

if(ret < 0){

768

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

769

int e = errno;

770

perror_plus("connect");

771

errno = e;

772

}

773

goto mandos_end;

774

}

775

776

if(quit_now){

777

errno = EINTR;

778

goto mandos_end;

1351

if(af == AF_INET6){

1352

ret = getnameinfo((struct sockaddr *)&to,

1353

sizeof(struct sockaddr_in6),

1354

addrstr, sizeof(addrstr), NULL, 0,

1355

NI_NUMERICHOST);

1356

} else {

1357

ret = getnameinfo((struct sockaddr *)&to,

1358

sizeof(struct sockaddr_in),

1359

addrstr, sizeof(addrstr), NULL, 0,

1360

NI_NUMERICHOST);

1361

}

1362

if(ret == EAI_SYSTEM){

1363

perror_plus("getnameinfo");

1364

} else if(ret != 0) {

1365

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1366

} else if(strcmp(addrstr, ip) != 0){

1367

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1368

}

1369

}

1370

1371

if(quit_now){

1372

errno = EINTR;

1373

goto mandos_end;

1374

}

1375

1376

while(true){

1377

if(af == AF_INET6){

1378

ret = connect(tcp_sd, (struct sockaddr *)&to,

1379

sizeof(struct sockaddr_in6));

1380

} else {

1381

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1382

sizeof(struct sockaddr_in));

1383

}

1384

if(ret < 0){

1385

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1386

and if_index != AVAHI_IF_UNSPEC

1387

and connect_to == NULL

1388

and not route_added and

1389

((af == AF_INET6 and not

1390

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1391

&to)->sin6_addr)))

1392

or (af == AF_INET and

1393

/* Not a a IPv4LL address */

1394

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1395

& 0xFFFF0000L) != 0xA9FE0000L))){

1396

/* Work around Avahi bug - Avahi does not announce link-local

1397

addresses if it has a global address, so local hosts with

1398

*only* a link-local address (e.g. Mandos clients) cannot

1399

connect to a Mandos server announced by Avahi on a server

1400

host with a global address. Work around this by retrying

1401

with an explicit route added with the server's address.

1402

1403

Avahi bug reference:

1404

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1405

https://bugs.debian.org/587961

1406

*/

1407

if(debug){

1408

fprintf_plus(stderr, "Mandos server unreachable, trying"

1409

" direct route\n");

1410

}

1411

int e = errno;

1412

route_added = add_local_route(ip, if_index);

1413

if(route_added){

1414

continue;

1415

}

1416

errno = e;

1417

}

1418

if(errno != ECONNREFUSED or debug){

1419

int e = errno;

1420

perror_plus("connect");

1421

errno = e;

1422

}

1423

goto mandos_end;

1424

}

1425

1426

if(quit_now){

1427

errno = EINTR;

1428

goto mandos_end;

1429

}

1430

break;

779

1431

}

780

1432

781

1433

const char *out = mandos_protocol_version;

817

1469

goto mandos_end;

818

1470

}

819

1471

820

/* Spurious warning from -Wint-to-pointer-cast */

821

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1472

/* This casting via intptr_t is to eliminate warning about casting

1473

an int to a pointer type. This is exactly how the GnuTLS Guile

1474

function "set-session-transport-fd!" does it. */

1475

gnutls_transport_set_ptr(session,

1476

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

822

1477

823

1478

if(quit_now){

824

1479

errno = EINTR;

929

1584

if(buffer_length > 0){

930

1585

ssize_t decrypted_buffer_size;

931

1586

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

932

&decrypted_buffer);

1587

&decrypted_buffer, mc);

933

1588

if(decrypted_buffer_size >= 0){

934

1589

1590

clearerr(stdout);

935

1591

written = 0;

936

1592

while(written < (size_t) decrypted_buffer_size){

937

1593

if(quit_now){

953

1609

}

954

1610

written += (size_t)ret;

955

1611

}

1612

ret = fflush(stdout);

1613

if(ret != 0){

1614

int e = errno;

1615

if(debug){

1616

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1617

strerror(errno));

1618

}

1619

errno = e;

1620

goto mandos_end;

1621

}

956

1622

retval = 0;

957

1623

}

958

1624

}

961

1627

962

1628

mandos_end:

963

1629

{

1630

if(route_added){

1631

if(not delete_local_route(ip, if_index)){

1632

fprintf_plus(stderr, "Failed to delete local route to %s on"

1633

" interface %d", ip, if_index);

1634

}

1635

}

964

1636

int e = errno;

965

1637

free(decrypted_buffer);

966

1638

free(buffer);

967

1639

if(tcp_sd >= 0){

968

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

1640

ret = close(tcp_sd);

969

1641

}

970

1642

if(ret == -1){

971

1643

if(e == 0){

996

1668

AVAHI_GCC_UNUSED AvahiStringList *txt,

997

1669

AVAHI_GCC_UNUSED AvahiLookupResultFlags

998

1670

flags,

999

AVAHI_GCC_UNUSED void* userdata){

1000

assert(r);

1671

void *mc){

1672

if(r == NULL){

1673

return;

1674

}

1001

1675

1002

1676

/* Called whenever a service has been resolved successfully or

1003

1677

timed out */

1004

1678

1005

1679

if(quit_now){

1680

avahi_s_service_resolver_free(r);

1006

1681

return;

1007

1682

}

1008

1683

1012

1687

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1013

1688

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1014

1689

domain,

1015

avahi_strerror(avahi_server_errno(mc.server)));

1690

avahi_strerror(avahi_server_errno

1691

(((mandos_context*)mc)->server)));

1016

1692

break;

1017

1693

1018

1694

case AVAHI_RESOLVER_FOUND:

1024

1700

PRIdMAX ") on port %" PRIu16 "\n", name,

1025

1701

host_name, ip, (intmax_t)interface, port);

1026

1702

}

1027

int ret = start_mandos_communication(ip, port, interface,

1028

avahi_proto_to_af(proto));

1703

int ret = start_mandos_communication(ip, (in_port_t)port,

1704

interface,

1705

avahi_proto_to_af(proto),

1706

mc);

1029

1707

if(ret == 0){

1030

avahi_simple_poll_quit(mc.simple_poll);

1708

avahi_simple_poll_quit(simple_poll);

1031

1709

} else {

1032

ret = add_server(ip, port, interface,

1033

avahi_proto_to_af(proto));

1710

if(not add_server(ip, (in_port_t)port, interface,

1711

avahi_proto_to_af(proto),

1712

&((mandos_context*)mc)->current_server)){

1713

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1714

" list\n", name);

1715

}

1034

1716

}

1035

1717

}

1036

1718

}

1046

1728

const char *domain,

1047

1729

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1048

1730

flags,

1049

AVAHI_GCC_UNUSED void* userdata){

1050

assert(b);

1731

void *mc){

1732

if(b == NULL){

1733

return;

1734

}

1051

1735

1052

1736

/* Called whenever a new services becomes available on the LAN or

1053

1737

is removed from the LAN */

1061

1745

case AVAHI_BROWSER_FAILURE:

1062

1746

1063

1747

fprintf_plus(stderr, "(Avahi browser) %s\n",

1064

avahi_strerror(avahi_server_errno(mc.server)));

1065

avahi_simple_poll_quit(mc.simple_poll);

1748

avahi_strerror(avahi_server_errno

1749

(((mandos_context*)mc)->server)));

1750

avahi_simple_poll_quit(simple_poll);

1066

1751

return;

1067

1752

1068

1753

case AVAHI_BROWSER_NEW:

1071

1756

the callback function is called the Avahi server will free the

1072

1757

resolver for us. */

1073

1758

1074

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1075

name, type, domain, protocol, 0,

1076

resolve_callback, NULL) == NULL)

1759

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1760

interface, protocol, name, type,

1761

domain, protocol, 0,

1762

resolve_callback, mc) == NULL)

1077

1763

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1078

1764

" %s\n", name,

1079

avahi_strerror(avahi_server_errno(mc.server)));

1765

avahi_strerror(avahi_server_errno

1766

(((mandos_context*)mc)->server)));

1080

1767

break;

1081

1768

1082

1769

case AVAHI_BROWSER_REMOVE:

1101

1788

signal_received = sig;

1102

1789

int old_errno = errno;

1103

1790

/* set main loop to exit */

1104

if(mc.simple_poll != NULL){

1105

avahi_simple_poll_quit(mc.simple_poll);

1791

if(simple_poll != NULL){

1792

avahi_simple_poll_quit(simple_poll);

1106

1793

}

1107

1794

errno = old_errno;

1108

1795

}

1109

1796

1797

__attribute__((nonnull, warn_unused_result))

1110

1798

bool get_flags(const char *ifname, struct ifreq *ifr){

1111

1799

int ret;

1800

int old_errno;

1112

1801

1113

1802

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1114

1803

if(s < 0){

1804

old_errno = errno;

1115

1805

perror_plus("socket");

1806

errno = old_errno;

1116

1807

return false;

1117

1808

}

1118

strcpy(ifr->ifr_name, ifname);

1809

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1810

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1119

1811

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1120

1812

if(ret == -1){

1121

1813

if(debug){

1814

old_errno = errno;

1122

1815

perror_plus("ioctl SIOCGIFFLAGS");

1816

errno = old_errno;

1817

}

1818

if((close(s) == -1) and debug){

1819

old_errno = errno;

1820

perror_plus("close");

1821

errno = old_errno;

1123

1822

}

1124

1823

return false;

1125

1824

}

1825

if((close(s) == -1) and debug){

1826

old_errno = errno;

1827

perror_plus("close");

1828

errno = old_errno;

1829

}

1126

1830

return true;

1127

1831

}

1128

1832

1833

__attribute__((nonnull, warn_unused_result))

1129

1834

bool good_flags(const char *ifname, const struct ifreq *ifr){

1130

1835

1131

1836

/* Reject the loopback device */

1173

1878

* corresponds to an acceptable network device.

1174

1879

* (This function is passed to scandir(3) as a filter function.)

1175

1880

*/

1881

__attribute__((nonnull, warn_unused_result))

1176

1882

int good_interface(const struct dirent *if_entry){

1177

1883

if(if_entry->d_name[0] == '.'){

1178

1884

return 0;

1194

1900

}

1195

1901

1196

1902

/*

1197

* This function determines if a directory entry in /sys/class/net

1198

* corresponds to an acceptable network device which is up.

1199

* (This function is passed to scandir(3) as a filter function.)

1200

*/

1201

int up_interface(const struct dirent *if_entry){

1202

if(if_entry->d_name[0] == '.'){

1203

return 0;

1204

}

1205

1206

struct ifreq ifr;

1207

if(not get_flags(if_entry->d_name, &ifr)){

1208

if(debug){

1209

fprintf_plus(stderr, "Failed to get flags for interface "

1210

"\"%s\"\n", if_entry->d_name);

1211

}

1212

return 0;

1213

}

1214

1215

/* Reject down interfaces */

1216

if(not (ifr.ifr_flags & IFF_UP)){

1217

if(debug){

1218

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1219

if_entry->d_name);

1220

}

1221

return 0;

1222

}

1223

1224

/* Reject non-running interfaces */

1225

if(not (ifr.ifr_flags & IFF_RUNNING)){

1226

if(debug){

1227

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1228

if_entry->d_name);

1229

}

1230

return 0;

1231

}

1232

1233

if(not good_flags(if_entry->d_name, &ifr)){

1234

return 0;

1235

}

1236

return 1;

1237

}

1238

1903

* This function determines if a network interface is up.

1904

*/

1905

__attribute__((nonnull, warn_unused_result))

1906

bool interface_is_up(const char *interface){

1907

struct ifreq ifr;

1908

if(not get_flags(interface, &ifr)){

1909

if(debug){

1910

fprintf_plus(stderr, "Failed to get flags for interface "

1911

"\"%s\"\n", interface);

1912

}

1913

return false;

1914

}

1915

1916

return (bool)(ifr.ifr_flags & IFF_UP);

1917

}

1918

1919

/*

1920

* This function determines if a network interface is running

1921

*/

1922

__attribute__((nonnull, warn_unused_result))

1923

bool interface_is_running(const char *interface){

1924

struct ifreq ifr;

1925

if(not get_flags(interface, &ifr)){

1926

if(debug){

1927

fprintf_plus(stderr, "Failed to get flags for interface "

1928

"\"%s\"\n", interface);

1929

}

1930

return false;

1931

}

1932

1933

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1934

}

1935

1936

__attribute__((nonnull, pure, warn_unused_result))

1239

1937

int notdotentries(const struct dirent *direntry){

1240

1938

/* Skip "." and ".." */

1241

1939

if(direntry->d_name[0] == '.'

1248

1946

}

1249

1947

1250

1948

/* Is this directory entry a runnable program? */

1949

__attribute__((nonnull, warn_unused_result))

1251

1950

int runnable_hook(const struct dirent *direntry){

1252

1951

int ret;

1253

1952

size_t sret;

1261

1960

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1262

1961

"abcdefghijklmnopqrstuvwxyz"

1263

1962

"0123456789"

1264

"_-");

1963

"_.-");

1265

1964

if((direntry->d_name)[sret] != '\0'){

1266

1965

/* Contains non-allowed characters */

1267

1966

if(debug){

1271

1970

return 0;

1272

1971

}

1273

1972

1274

char *fullname = NULL;

1275

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1276

if(ret < 0){

1277

perror_plus("asprintf");

1278

return 0;

1279

}

1280

1281

ret = stat(fullname, &st);

1973

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1282

1974

if(ret == -1){

1283

1975

if(debug){

1284

1976

perror_plus("Could not stat hook");

1301

1993

}

1302

1994

return 0;

1303

1995

}

1996

if(debug){

1997

fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",

1998

direntry->d_name);

1999

}

1304

2000

return 1;

1305

2001

}

1306

2002

1307

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

2003

__attribute__((nonnull, warn_unused_result))

2004

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

2005

mandos_context *mc){

1308

2006

int ret;

1309

2007

struct timespec now;

1310

2008

struct timespec waited_time;

1311

2009

intmax_t block_time;

1312

2010

1313

2011

while(true){

1314

if(mc.current_server == NULL){

1315

if (debug){

2012

if(mc->current_server == NULL){

2013

if(debug){

1316

2014

fprintf_plus(stderr, "Wait until first server is found."

1317

2015

" No timeout!\n");

1318

2016

}

1319

2017

ret = avahi_simple_poll_iterate(s, -1);

1320

2018

} else {

1321

if (debug){

2019

if(debug){

1322

2020

fprintf_plus(stderr, "Check current_server if we should run"

1323

2021

" it, or wait\n");

1324

2022

}

1331

2029

/* Calculating in ms how long time between now and server

1332

2030

who we visted longest time ago. Now - last seen. */

1333

2031

waited_time.tv_sec = (now.tv_sec

1334

- mc.current_server->last_seen.tv_sec);

2032

- mc->current_server->last_seen.tv_sec);

1335

2033

waited_time.tv_nsec = (now.tv_nsec

1336

- mc.current_server->last_seen.tv_nsec);

2034

- mc->current_server->last_seen.tv_nsec);

1337

2035

/* total time is 10s/10,000ms.

1338

2036

Converting to s from ms by dividing by 1,000,

1339

2037

and ns to ms by dividing by 1,000,000. */

1341

2039

- ((intmax_t)waited_time.tv_sec * 1000))

1342

2040

- ((intmax_t)waited_time.tv_nsec / 1000000));

1343

2041

1344

if (debug){

2042

if(debug){

1345

2043

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

1346

2044

block_time);

1347

2045

}

1348

2046

1349

2047

if(block_time <= 0){

1350

ret = start_mandos_communication(mc.current_server->ip,

1351

mc.current_server->port,

1352

mc.current_server->if_index,

1353

mc.current_server->af);

2048

ret = start_mandos_communication(mc->current_server->ip,

2049

mc->current_server->port,

2050

mc->current_server->if_index,

2051

mc->current_server->af, mc);

1354

2052

if(ret == 0){

1355

avahi_simple_poll_quit(mc.simple_poll);

2053

avahi_simple_poll_quit(s);

1356

2054

return 0;

1357

2055

}

1358

2056

ret = clock_gettime(CLOCK_MONOTONIC,

1359

&mc.current_server->last_seen);

2057

&mc->current_server->last_seen);

1360

2058

if(ret == -1){

1361

2059

perror_plus("clock_gettime");

1362

2060

return -1;

1363

2061

}

1364

mc.current_server = mc.current_server->next;

2062

mc->current_server = mc->current_server->next;

1365

2063

block_time = 0; /* Call avahi to find new Mandos

1366

2064

servers, but don't block */

1367

2065

}

1369

2067

ret = avahi_simple_poll_iterate(s, (int)block_time);

1370

2068

}

1371

2069

if(ret != 0){

1372

if (ret > 0 or errno != EINTR){

2070

if(ret > 0 or errno != EINTR){

1373

2071

return (ret != 1) ? ret : 0;

1374

2072

}

1375

2073

}

1376

2074

}

1377

2075

}

1378

2076

1379

bool run_network_hooks(const char *mode, const char *interface,

2077

__attribute__((nonnull))

2078

void run_network_hooks(const char *mode, const char *interface,

1380

2079

const float delay){

1381

struct dirent **direntries;

1382

struct dirent *direntry;

1383

int ret;

1384

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1385

alphasort);

2080

struct dirent **direntries = NULL;

2081

if(hookdir_fd == -1){

2082

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2083

| O_CLOEXEC);

2084

if(hookdir_fd == -1){

2085

if(errno == ENOENT){

2086

if(debug){

2087

fprintf_plus(stderr, "Network hook directory \"%s\" not"

2088

" found\n", hookdir);

2089

}

2090

} else {

2091

perror_plus("open");

2092

}

2093

return;

2094

}

2095

}

2096

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

2097

if(devnull == -1){

2098

perror_plus("open(\"/dev/null\", O_RDONLY)");

2099

return;

2100

}

2101

int numhooks = scandirat(hookdir_fd, ".", &direntries,

2102

runnable_hook, alphasort);

1386

2103

if(numhooks == -1){

1387

2104

perror_plus("scandir");

1388

} else {

1389

int devnull = open("/dev/null", O_RDONLY);

1390

for(int i = 0; i < numhooks; i++){

1391

direntry = direntries[0];

1392

char *fullname = NULL;

1393

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1394

if(ret < 0){

2105

close(devnull);

2106

return;

2107

}

2108

struct dirent *direntry;

2109

int ret;

2110

for(int i = 0; i < numhooks; i++){

2111

direntry = direntries[i];

2112

if(debug){

2113

fprintf_plus(stderr, "Running network hook \"%s\"\n",

2114

direntry->d_name);

2115

}

2116

pid_t hook_pid = fork();

2117

if(hook_pid == 0){

2118

/* Child */

2119

/* Raise privileges */

2120

errno = raise_privileges_permanently();

2121

if(errno != 0){

2122

perror_plus("Failed to raise privileges");

2123

_exit(EX_NOPERM);

2124

}

2125

/* Set group */

2126

errno = 0;

2127

ret = setgid(0);

2128

if(ret == -1){

2129

perror_plus("setgid");

2130

_exit(EX_NOPERM);

2131

}

2132

/* Reset supplementary groups */

2133

errno = 0;

2134

ret = setgroups(0, NULL);

2135

if(ret == -1){

2136

perror_plus("setgroups");

2137

_exit(EX_NOPERM);

2138

}

2139

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

2140

if(ret == -1){

2141

perror_plus("setenv");

2142

_exit(EX_OSERR);

2143

}

2144

ret = setenv("DEVICE", interface, 1);

2145

if(ret == -1){

2146

perror_plus("setenv");

2147

_exit(EX_OSERR);

2148

}

2149

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

2150

if(ret == -1){

2151

perror_plus("setenv");

2152

_exit(EX_OSERR);

2153

}

2154

ret = setenv("MODE", mode, 1);

2155

if(ret == -1){

2156

perror_plus("setenv");

2157

_exit(EX_OSERR);

2158

}

2159

char *delaystring;

2160

ret = asprintf(&delaystring, "%f", (double)delay);

2161

if(ret == -1){

1395

2162

perror_plus("asprintf");

1396

continue;

2163

_exit(EX_OSERR);

1397

2164

}

1398

pid_t hook_pid = fork();

1399

if(hook_pid == 0){

1400

/* Child */

1401

dup2(devnull, STDIN_FILENO);

1402

close(devnull);

1403

dup2(STDERR_FILENO, STDOUT_FILENO);

1404

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1405

if(ret == -1){

1406

perror_plus("setenv");

1407

return false;

1408

}

1409

ret = setenv("DEVICE", interface, 1);

1410

if(ret == -1){

1411

perror_plus("setenv");

1412

return false;

1413

}

1414

ret = setenv("VERBOSE", debug ? "1" : "0", 1);

1415

if(ret == -1){

1416

perror_plus("setenv");

1417

return false;

1418

}

1419

ret = setenv("MODE", mode, 1);

1420

if(ret == -1){

1421

perror_plus("setenv");

1422

return false;

1423

}

1424

char *delaystring;

1425

ret = asprintf(&delaystring, "%f", delay);

1426

if(ret == -1){

1427

perror_plus("asprintf");

1428

return false;

1429

}

1430

ret = setenv("DELAY", delaystring, 1);

1431

if(ret == -1){

1432

free(delaystring);

1433

perror_plus("setenv");

1434

return false;

1435

}

2165

ret = setenv("DELAY", delaystring, 1);

2166

if(ret == -1){

1436

2167

free(delaystring);

1437

ret = execl(fullname, direntry->d_name, mode, NULL);

1438

perror_plus("execl");

1439

} else {

1440

int status;

1441

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1442

perror_plus("waitpid");

1443

free(fullname);

1444

continue;

1445

}

1446

if(WIFEXITED(status)){

1447

if(WEXITSTATUS(status) != 0){

1448

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1449

" with status %d\n", direntry->d_name,

1450

WEXITSTATUS(status));

1451

free(fullname);

1452

continue;

1453

}

1454

} else if(WIFSIGNALED(status)){

1455

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1456

" signal %d\n", direntry->d_name,

1457

WTERMSIG(status));

1458

free(fullname);

1459

continue;

1460

} else {

1461

fprintf_plus(stderr, "Warning: network hook \"%s\""

1462

" crashed\n", direntry->d_name);

1463

free(fullname);

1464

continue;

1465

}

1466

}

1467

free(fullname);

1468

if(quit_now){

1469

break;

1470

}

1471

}

1472

close(devnull);

1473

}

1474

return true;

2168

perror_plus("setenv");

2169

_exit(EX_OSERR);

2170

}

2171

free(delaystring);

2172

if(connect_to != NULL){

2173

ret = setenv("CONNECT", connect_to, 1);

2174

if(ret == -1){

2175

perror_plus("setenv");

2176

_exit(EX_OSERR);

2177

}

2178

}

2179

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2180

direntry->d_name,

2181

O_RDONLY));

2182

if(hook_fd == -1){

2183

perror_plus("openat");

2184

_exit(EXIT_FAILURE);

2185

}

2186

if(close(hookdir_fd) == -1){

2187

perror_plus("close");

2188

_exit(EXIT_FAILURE);

2189

}

2190

ret = dup2(devnull, STDIN_FILENO);

2191

if(ret == -1){

2192

perror_plus("dup2(devnull, STDIN_FILENO)");

2193

_exit(EX_OSERR);

2194

}

2195

ret = close(devnull);

2196

if(ret == -1){

2197

perror_plus("close");

2198

_exit(EX_OSERR);

2199

}

2200

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2201

if(ret == -1){

2202

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2203

_exit(EX_OSERR);

2204

}

2205

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2206

environ) == -1){

2207

perror_plus("fexecve");

2208

_exit(EXIT_FAILURE);

2209

}

2210

} else {

2211

if(hook_pid == -1){

2212

perror_plus("fork");

2213

free(direntry);

2214

continue;

2215

}

2216

int status;

2217

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2218

perror_plus("waitpid");

2219

free(direntry);

2220

continue;

2221

}

2222

if(WIFEXITED(status)){

2223

if(WEXITSTATUS(status) != 0){

2224

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2225

" with status %d\n", direntry->d_name,

2226

WEXITSTATUS(status));

2227

free(direntry);

2228

continue;

2229

}

2230

} else if(WIFSIGNALED(status)){

2231

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2232

" signal %d\n", direntry->d_name,

2233

WTERMSIG(status));

2234

free(direntry);

2235

continue;

2236

} else {

2237

fprintf_plus(stderr, "Warning: network hook \"%s\""

2238

" crashed\n", direntry->d_name);

2239

free(direntry);

2240

continue;

2241

}

2242

}

2243

if(debug){

2244

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2245

direntry->d_name);

2246

}

2247

free(direntry);

2248

}

2249

free(direntries);

2250

if(close(hookdir_fd) == -1){

2251

perror_plus("close");

2252

} else {

2253

hookdir_fd = -1;

2254

}

2255

close(devnull);

2256

}

2257

2258

__attribute__((nonnull, warn_unused_result))

2259

int bring_up_interface(const char *const interface,

2260

const float delay){

2261

int old_errno = errno;

2262

int ret;

2263

struct ifreq network;

2264

unsigned int if_index = if_nametoindex(interface);

2265

if(if_index == 0){

2266

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2267

errno = old_errno;

2268

return ENXIO;

2269

}

2270

2271

if(quit_now){

2272

errno = old_errno;

2273

return EINTR;

2274

}

2275

2276

if(not interface_is_up(interface)){

2277

int ret_errno = 0;

2278

int ioctl_errno = 0;

2279

if(not get_flags(interface, &network)){

2280

ret_errno = errno;

2281

fprintf_plus(stderr, "Failed to get flags for interface "

2282

"\"%s\"\n", interface);

2283

errno = old_errno;

2284

return ret_errno;

2285

}

2286

network.ifr_flags |= IFF_UP; /* set flag */

2287

2288

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2289

if(sd == -1){

2290

ret_errno = errno;

2291

perror_plus("socket");

2292

errno = old_errno;

2293

return ret_errno;

2294

}

2295

2296

if(quit_now){

2297

ret = close(sd);

2298

if(ret == -1){

2299

perror_plus("close");

2300

}

2301

errno = old_errno;

2302

return EINTR;

2303

}

2304

2305

if(debug){

2306

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2307

interface);

2308

}

2309

2310

/* Raise privileges */

2311

ret_errno = raise_privileges();

2312

if(ret_errno != 0){

2313

errno = ret_errno;

2314

perror_plus("Failed to raise privileges");

2315

}

2316

2317

#ifdef __linux__

2318

int ret_linux;

2319

bool restore_loglevel = false;

2320

if(ret_errno == 0){

2321

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2322

messages about the network interface to mess up the prompt */

2323

ret_linux = klogctl(8, NULL, 5);

2324

if(ret_linux == -1){

2325

perror_plus("klogctl");

2326

} else {

2327

restore_loglevel = true;

2328

}

2329

}

2330

#endif /* __linux__ */

2331

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2332

ioctl_errno = errno;

2333

#ifdef __linux__

2334

if(restore_loglevel){

2335

ret_linux = klogctl(7, NULL, 0);

2336

if(ret_linux == -1){

2337

perror_plus("klogctl");

2338

}

2339

}

2340

#endif /* __linux__ */

2341

2342

/* If raise_privileges() succeeded above */

2343

if(ret_errno == 0){

2344

/* Lower privileges */

2345

ret_errno = lower_privileges();

2346

if(ret_errno != 0){

2347

errno = ret_errno;

2348

perror_plus("Failed to lower privileges");

2349

}

2350

}

2351

2352

/* Close the socket */

2353

ret = close(sd);

2354

if(ret == -1){

2355

perror_plus("close");

2356

}

2357

2358

if(ret_setflags == -1){

2359

errno = ioctl_errno;

2360

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2361

errno = old_errno;

2362

return ioctl_errno;

2363

}

2364

} else if(debug){

2365

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

2366

interface);

2367

}

2368

2369

/* Sleep checking until interface is running.

2370

Check every 0.25s, up to total time of delay */

2371

for(int i = 0; i < delay * 4; i++){

2372

if(interface_is_running(interface)){

2373

break;

2374

}

2375

struct timespec sleeptime = { .tv_nsec = 250000000 };

2376

ret = nanosleep(&sleeptime, NULL);

2377

if(ret == -1 and errno != EINTR){

2378

perror_plus("nanosleep");

2379

}

2380

}

2381

2382

errno = old_errno;

2383

return 0;

2384

}

2385

2386

__attribute__((nonnull, warn_unused_result))

2387

int take_down_interface(const char *const interface){

2388

int old_errno = errno;

2389

struct ifreq network;

2390

unsigned int if_index = if_nametoindex(interface);

2391

if(if_index == 0){

2392

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2393

errno = old_errno;

2394

return ENXIO;

2395

}

2396

if(interface_is_up(interface)){

2397

int ret_errno = 0;

2398

int ioctl_errno = 0;

2399

if(not get_flags(interface, &network) and debug){

2400

ret_errno = errno;

2401

fprintf_plus(stderr, "Failed to get flags for interface "

2402

"\"%s\"\n", interface);

2403

errno = old_errno;

2404

return ret_errno;

2405

}

2406

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2407

2408

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2409

if(sd == -1){

2410

ret_errno = errno;

2411

perror_plus("socket");

2412

errno = old_errno;

2413

return ret_errno;

2414

}

2415

2416

if(debug){

2417

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2418

interface);

2419

}

2420

2421

/* Raise privileges */

2422

ret_errno = raise_privileges();

2423

if(ret_errno != 0){

2424

errno = ret_errno;

2425

perror_plus("Failed to raise privileges");

2426

}

2427

2428

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2429

ioctl_errno = errno;

2430

2431

/* If raise_privileges() succeeded above */

2432

if(ret_errno == 0){

2433

/* Lower privileges */

2434

ret_errno = lower_privileges();

2435

if(ret_errno != 0){

2436

errno = ret_errno;

2437

perror_plus("Failed to lower privileges");

2438

}

2439

}

2440

2441

/* Close the socket */

2442

int ret = close(sd);

2443

if(ret == -1){

2444

perror_plus("close");

2445

}

2446

2447

if(ret_setflags == -1){

2448

errno = ioctl_errno;

2449

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2450

errno = old_errno;

2451

return ioctl_errno;

2452

}

2453

} else if(debug){

2454

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

2455

interface);

2456

}

2457

2458

errno = old_errno;

2459

return 0;

1475

2460

}

1476

2461

1477

2462

int main(int argc, char *argv[]){

2463

mandos_context mc = { .server = NULL, .dh_bits = 0,

2464

#if GNUTLS_VERSION_NUMBER >= 0x030606

2465

.priority = "SECURE128:!CTYPE-X.509"

2466

":+CTYPE-RAWPK:!RSA:!VERS-ALL:+VERS-TLS1.3"

2467

":%PROFILE_ULTRA",

2468

#elif GNUTLS_VERSION_NUMBER < 0x030600

2469

.priority = "SECURE256:!CTYPE-X.509"

2470

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2471

#else

2472

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

2473

#endif

2474

.current_server = NULL, .interfaces = NULL,

2475

.interfaces_size = 0 };

1478

2476

AvahiSServiceBrowser *sb = NULL;

1479

int error;

2477

error_t ret_errno;

1480

2478

int ret;

1481

2479

intmax_t tmpmax;

1482

2480

char *tmp;

1483

2481

int exitcode = EXIT_SUCCESS;

1484

const char *interface = "";

1485

struct ifreq network;

1486

int sd = -1;

1487

bool take_down_interface = false;

1488

uid_t uid;

1489

gid_t gid;

1490

char tempdir[] = "/tmp/mandosXXXXXX";

1491

bool tempdir_created = false;

2482

char *interfaces_to_take_down = NULL;

2483

size_t interfaces_to_take_down_size = 0;

2484

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2485

char old_tempdir[] = "/tmp/mandosXXXXXX";

2486

char *tempdir = NULL;

1492

2487

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1493

2488

const char *seckey = PATHDIR "/" SECKEY;

1494

2489

const char *pubkey = PATHDIR "/" PUBKEY;

2490

#if GNUTLS_VERSION_NUMBER >= 0x030606

2491

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2492

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2493

#endif

2494

const char *dh_params_file = NULL;

2495

char *interfaces_hooks = NULL;

1495

2496

1496

2497

bool gnutls_initialized = false;

1497

2498

bool gpgme_initialized = false;

1543

2544

{ .name = "pubkey", .key = 'p',

1544

2545

.arg = "FILE",

1545

2546

.doc = "OpenPGP public key file base name",

1546

.group = 2 },

2547

.group = 1 },

2548

{ .name = "tls-privkey", .key = 't',

2549

.arg = "FILE",

2550

#if GNUTLS_VERSION_NUMBER >= 0x030606

2551

.doc = "TLS private key file base name",

2552

#else

2553

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2554

#endif

2555

.group = 1 },

2556

{ .name = "tls-pubkey", .key = 'T',

2557

.arg = "FILE",

2558

#if GNUTLS_VERSION_NUMBER >= 0x030606

2559

.doc = "TLS public key file base name",

2560

#else

2561

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2562

#endif

2563

.group = 1 },

1547

2564

{ .name = "dh-bits", .key = 129,

1548

2565

.arg = "BITS",

1549

2566

.doc = "Bit length of the prime number used in the"

1550

2567

" Diffie-Hellman key exchange",

1551

2568

.group = 2 },

2569

{ .name = "dh-params", .key = 134,

2570

.arg = "FILE",

2571

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2572

" for the Diffie-Hellman key exchange",

2573

.group = 2 },

1552

2574

{ .name = "priority", .key = 130,

1553

2575

.arg = "STRING",

1554

2576

.doc = "GnuTLS priority string for the TLS handshake",

1559

2581

.group = 2 },

1560

2582

{ .name = "retry", .key = 132,

1561

2583

.arg = "SECONDS",

1562

.doc = "Retry interval used when denied by the mandos server",

2584

.doc = "Retry interval used when denied by the Mandos server",

1563

2585

.group = 2 },

1564

2586

{ .name = "network-hook-dir", .key = 133,

1565

2587

.arg = "DIR",

1588

2610

connect_to = arg;

1589

2611

break;

1590

2612

case 'i': /* --interface */

1591

interface = arg;

2613

ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,

2614

arg, (int)',');

2615

if(ret_errno != 0){

2616

argp_error(state, "%s", strerror(ret_errno));

2617

}

1592

2618

break;

1593

2619

case 's': /* --seckey */

1594

2620

seckey = arg;

1596

2622

case 'p': /* --pubkey */

1597

2623

pubkey = arg;

1598

2624

break;

2625

case 't': /* --tls-privkey */

2626

#if GNUTLS_VERSION_NUMBER >= 0x030606

2627

tls_privkey = arg;

2628

#endif

2629

break;

2630

case 'T': /* --tls-pubkey */

2631

#if GNUTLS_VERSION_NUMBER >= 0x030606

2632

tls_pubkey = arg;

2633

#endif

2634

break;

1599

2635

case 129: /* --dh-bits */

1600

2636

errno = 0;

1601

2637

tmpmax = strtoimax(arg, &tmp, 10);

1605

2641

}

1606

2642

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

1607

2643

break;

2644

case 134: /* --dh-params */

2645

dh_params_file = arg;

2646

break;

1608

2647

case 130: /* --priority */

1609

2648

mc.priority = arg;

1610

2649

break;

1633

2672

argp_state_help(state, state->out_stream,

1634

2673

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1635

2674

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2675

__builtin_unreachable();

1636

2676

case -3: /* --usage */

1637

2677

argp_state_help(state, state->out_stream,

1638

2678

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2679

__builtin_unreachable();

1639

2680

case 'V': /* --version */

1640

fprintf_plus(state->out_stream,

1641

"Mandos plugin mandos-client: ");

1642

2681

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

1643

2682

exit(argp_err_exit_status);

1644

2683

break;

1652

2691

.args_doc = "",

1653

2692

.doc = "Mandos client -- Get and decrypt"

1654

2693

" passwords from a Mandos server" };

1655

ret = argp_parse(&argp, argc, argv,

1656

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1657

switch(ret){

2694

ret_errno = argp_parse(&argp, argc, argv,

2695

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2696

switch(ret_errno){

1658

2697

case 0:

1659

2698

break;

1660

2699

case ENOMEM:

1661

2700

default:

1662

errno = ret;

2701

errno = ret_errno;

1663

2702

perror_plus("argp_parse");

1664

2703

exitcode = EX_OSERR;

1665

2704

goto end;

1668

2707

goto end;

1669

2708

}

1670

2709

}

1671

2710

1672

2711

{

1673

2712

/* Work around Debian bug #633582:

1674

<http://bugs.debian.org/633582> */

1675

struct stat st;

1676

1677

/* Re-raise priviliges */

1678

errno = 0;

1679

ret = seteuid(0);

1680

if(ret == -1){

1681

perror_plus("seteuid");

1682

}

1683

1684

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1685

int seckey_fd = open(seckey, O_RDONLY);

1686

if(seckey_fd == -1){

1687

perror_plus("open");

1688

} else {

1689

ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));

1690

if(ret == -1){

1691

perror_plus("fstat");

1692

} else {

1693

if(S_ISREG(st.st_mode)

1694

and st.st_uid == 0 and st.st_gid == 0){

1695

ret = fchown(seckey_fd, uid, gid);

1696

if(ret == -1){

1697

perror_plus("fchown");

1698

}

1699

}

1700

}

1701

TEMP_FAILURE_RETRY(close(seckey_fd));

1702

}

1703

}

1704

1705

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

1706

int pubkey_fd = open(pubkey, O_RDONLY);

1707

if(pubkey_fd == -1){

1708

perror_plus("open");

1709

} else {

1710

ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));

1711

if(ret == -1){

1712

perror_plus("fstat");

1713

} else {

1714

if(S_ISREG(st.st_mode)

1715

and st.st_uid == 0 and st.st_gid == 0){

1716

ret = fchown(pubkey_fd, uid, gid);

1717

if(ret == -1){

1718

perror_plus("fchown");

1719

}

1720

}

1721

}

1722

TEMP_FAILURE_RETRY(close(pubkey_fd));

1723

}

1724

}

1725

1726

/* Lower privileges */

1727

errno = 0;

1728

ret = seteuid(uid);

1729

if(ret == -1){

1730

perror_plus("seteuid");

2713

<https://bugs.debian.org/633582> */

2714

2715

/* Re-raise privileges */

2716

ret = raise_privileges();

2717

if(ret != 0){

2718

errno = ret;

2719

perror_plus("Failed to raise privileges");

2720

} else {

2721

struct stat st;

2722

2723

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

2724

int seckey_fd = open(seckey, O_RDONLY);

2725

if(seckey_fd == -1){

2726

perror_plus("open");

2727

} else {

2728

ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));

2729

if(ret == -1){

2730

perror_plus("fstat");

2731

} else {

2732

if(S_ISREG(st.st_mode)

2733

and st.st_uid == 0 and st.st_gid == 0){

2734

ret = fchown(seckey_fd, uid, gid);

2735

if(ret == -1){

2736

perror_plus("fchown");

2737

}

2738

}

2739

}

2740

close(seckey_fd);

2741

}

2742

}

2743

2744

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2745

int pubkey_fd = open(pubkey, O_RDONLY);

2746

if(pubkey_fd == -1){

2747

perror_plus("open");

2748

} else {

2749

ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));

2750

if(ret == -1){

2751

perror_plus("fstat");

2752

} else {

2753

if(S_ISREG(st.st_mode)

2754

and st.st_uid == 0 and st.st_gid == 0){

2755

ret = fchown(pubkey_fd, uid, gid);

2756

if(ret == -1){

2757

perror_plus("fchown");

2758

}

2759

}

2760

}

2761

close(pubkey_fd);

2762

}

2763

}

2764

2765

if(dh_params_file != NULL

2766

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2767

int dhparams_fd = open(dh_params_file, O_RDONLY);

2768

if(dhparams_fd == -1){

2769

perror_plus("open");

2770

} else {

2771

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2772

if(ret == -1){

2773

perror_plus("fstat");

2774

} else {

2775

if(S_ISREG(st.st_mode)

2776

and st.st_uid == 0 and st.st_gid == 0){

2777

ret = fchown(dhparams_fd, uid, gid);

2778

if(ret == -1){

2779

perror_plus("fchown");

2780

}

2781

}

2782

}

2783

close(dhparams_fd);

2784

}

2785

}

2786

2787

/* Lower privileges */

2788

ret = lower_privileges();

2789

if(ret != 0){

2790

errno = ret;

2791

perror_plus("Failed to lower privileges");

2792

}

2793

}

2794

}

2795

2796

/* Remove invalid interface names (except "none") */

2797

{

2798

char *interface = NULL;

2799

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2800

interface))){

2801

if(strcmp(interface, "none") != 0

2802

and if_nametoindex(interface) == 0){

2803

if(interface[0] != '\0'){

2804

fprintf_plus(stderr, "Not using nonexisting interface"

2805

" \"%s\"\n", interface);

2806

}

2807

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2808

interface = NULL;

2809

}

1731

2810

}

1732

2811

}

1733

2812

1734

2813

/* Run network hooks */

1735

2814

{

1736

/* Re-raise priviliges */

1737

errno = 0;

1738

ret = seteuid(0);

1739

if(ret == -1){

1740

perror_plus("seteuid");

1741

}

1742

if(not run_network_hooks("start", interface, delay)){

1743

goto end;

1744

}

1745

/* Lower privileges */

1746

errno = 0;

1747

ret = seteuid(uid);

1748

if(ret == -1){

1749

perror_plus("seteuid");

1750

}

2815

if(mc.interfaces != NULL){

2816

interfaces_hooks = malloc(mc.interfaces_size);

2817

if(interfaces_hooks == NULL){

2818

perror_plus("malloc");

2819

goto end;

2820

}

2821

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2822

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2823

}

2824

run_network_hooks("start", interfaces_hooks != NULL ?

2825

interfaces_hooks : "", delay);

1751

2826

}

1752

2827

1753

2828

if(not debug){

1754

2829

avahi_set_log_function(empty_log);

1755

2830

}

1756

2831

1757

if(interface[0] == '\0'){

1758

struct dirent **direntries;

1759

/* First look for interfaces that are up */

1760

ret = scandir(sys_class_net, &direntries, up_interface,

1761

alphasort);

1762

if(ret == 0){

1763

/* No up interfaces, look for any good interfaces */

1764

free(direntries);

1765

ret = scandir(sys_class_net, &direntries, good_interface,

1766

alphasort);

1767

}

1768

if(ret >= 1){

1769

/* Pick the first interface returned */

1770

interface = strdup(direntries[0]->d_name);

1771

if(debug){

1772

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1773

}

1774

if(interface == NULL){

1775

perror_plus("malloc");

1776

free(direntries);

1777

exitcode = EXIT_FAILURE;

1778

goto end;

1779

}

1780

free(direntries);

1781

} else {

1782

free(direntries);

1783

fprintf_plus(stderr, "Could not find a network interface\n");

1784

exitcode = EXIT_FAILURE;

1785

goto end;

1786

}

1787

}

1788

1789

2832

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1790

2833

from the signal handler */

1791

2834

/* Initialize the pseudo-RNG for Avahi */

1792

2835

srand((unsigned int) time(NULL));

1793

mc.simple_poll = avahi_simple_poll_new();

1794

if(mc.simple_poll == NULL){

2836

simple_poll = avahi_simple_poll_new();

2837

if(simple_poll == NULL){

1795

2838

fprintf_plus(stderr,

1796

2839

"Avahi: Failed to create simple poll object.\n");

1797

2840

exitcode = EX_UNAVAILABLE;

1861

2904

}

1862

2905

}

1863

2906

1864

/* If the interface is down, bring it up */

1865

if(strcmp(interface, "none") != 0){

1866

if_index = (AvahiIfIndex) if_nametoindex(interface);

1867

if(if_index == 0){

1868

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1869

exitcode = EX_UNAVAILABLE;

1870

goto end;

1871

}

1872

1873

if(quit_now){

1874

goto end;

1875

}

1876

1877

/* Re-raise priviliges */

1878

errno = 0;

1879

ret = seteuid(0);

1880

if(ret == -1){

1881

perror_plus("seteuid");

1882

}

1883

1884

#ifdef __linux__

1885

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1886

messages about the network interface to mess up the prompt */

1887

ret = klogctl(8, NULL, 5);

1888

bool restore_loglevel = true;

1889

if(ret == -1){

1890

restore_loglevel = false;

1891

perror_plus("klogctl");

1892

}

1893

#endif /* __linux__ */

1894

1895

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1896

if(sd < 0){

1897

perror_plus("socket");

1898

exitcode = EX_OSERR;

1899

#ifdef __linux__

1900

if(restore_loglevel){

1901

ret = klogctl(7, NULL, 0);

1902

if(ret == -1){

1903

perror_plus("klogctl");

1904

}

1905

}

1906

#endif /* __linux__ */

1907

/* Lower privileges */

1908

errno = 0;

1909

ret = seteuid(uid);

1910

if(ret == -1){

1911

perror_plus("seteuid");

1912

}

1913

goto end;

1914

}

1915

strcpy(network.ifr_name, interface);

1916

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1917

if(ret == -1){

1918

perror_plus("ioctl SIOCGIFFLAGS");

1919

#ifdef __linux__

1920

if(restore_loglevel){

1921

ret = klogctl(7, NULL, 0);

1922

if(ret == -1){

1923

perror_plus("klogctl");

1924

}

1925

}

1926

#endif /* __linux__ */

1927

exitcode = EX_OSERR;

1928

/* Lower privileges */

1929

errno = 0;

1930

ret = seteuid(uid);

1931

if(ret == -1){

1932

perror_plus("seteuid");

1933

}

1934

goto end;

1935

}

1936

if((network.ifr_flags & IFF_UP) == 0){

1937

network.ifr_flags |= IFF_UP;

1938

take_down_interface = true;

1939

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1940

if(ret == -1){

1941

take_down_interface = false;

1942

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1943

exitcode = EX_OSERR;

1944

#ifdef __linux__

1945

if(restore_loglevel){

1946

ret = klogctl(7, NULL, 0);

1947

if(ret == -1){

1948

perror_plus("klogctl");

2907

/* If no interfaces were specified, make a list */

2908

if(mc.interfaces == NULL){

2909

struct dirent **direntries = NULL;

2910

/* Look for any good interfaces */

2911

ret = scandir(sys_class_net, &direntries, good_interface,

2912

alphasort);

2913

if(ret >= 1){

2914

/* Add all found interfaces to interfaces list */

2915

for(int i = 0; i < ret; ++i){

2916

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2917

direntries[i]->d_name);

2918

if(ret_errno != 0){

2919

errno = ret_errno;

2920

perror_plus("argz_add");

2921

free(direntries[i]);

2922

continue;

2923

}

2924

if(debug){

2925

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2926

direntries[i]->d_name);

2927

}

2928

free(direntries[i]);

2929

}

2930

free(direntries);

2931

} else {

2932

if(ret == 0){

2933

free(direntries);

2934

}

2935

fprintf_plus(stderr, "Could not find a network interface\n");

2936

exitcode = EXIT_FAILURE;

2937

goto end;

2938

}

2939

}

2940

2941

/* Bring up interfaces which are down, and remove any "none"s */

2942

{

2943

char *interface = NULL;

2944

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2945

interface))){

2946

/* If interface name is "none", stop bringing up interfaces.

2947

Also remove all instances of "none" from the list */

2948

if(strcmp(interface, "none") == 0){

2949

argz_delete(&mc.interfaces, &mc.interfaces_size,

2950

interface);

2951

interface = NULL;

2952

while((interface = argz_next(mc.interfaces,

2953

mc.interfaces_size, interface))){

2954

if(strcmp(interface, "none") == 0){

2955

argz_delete(&mc.interfaces, &mc.interfaces_size,

2956

interface);

2957

interface = NULL;

1949

2958

}

1950

2959

}

1951

#endif /* __linux__ */

1952

/* Lower privileges */

1953

errno = 0;

1954

ret = seteuid(uid);

1955

if(ret == -1){

1956

perror_plus("seteuid");

1957

}

1958

goto end;

1959

}

1960

}

1961

/* Sleep checking until interface is running.

1962

Check every 0.25s, up to total time of delay */

1963

for(int i=0; i < delay * 4; i++){

1964

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1965

if(ret == -1){

1966

perror_plus("ioctl SIOCGIFFLAGS");

1967

} else if(network.ifr_flags & IFF_RUNNING){

1968

2960

break;

1969

2961

}

1970

struct timespec sleeptime = { .tv_nsec = 250000000 };

1971

ret = nanosleep(&sleeptime, NULL);

1972

if(ret == -1 and errno != EINTR){

1973

perror_plus("nanosleep");

1974

}

1975

}

1976

if(not take_down_interface){

1977

/* We won't need the socket anymore */

1978

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1979

if(ret == -1){

1980

perror_plus("close");

1981

}

1982

}

1983

#ifdef __linux__

1984

if(restore_loglevel){

1985

/* Restores kernel loglevel to default */

1986

ret = klogctl(7, NULL, 0);

1987

if(ret == -1){

1988

perror_plus("klogctl");

1989

}

1990

}

1991

#endif /* __linux__ */

1992

/* Lower privileges */

1993

errno = 0;

1994

/* Lower privileges */

1995

ret = seteuid(uid);

1996

if(ret == -1){

1997

perror_plus("seteuid");

1998

}

2962

bool interface_was_up = interface_is_up(interface);

2963

errno = bring_up_interface(interface, delay);

2964

if(not interface_was_up){

2965

if(errno != 0){

2966

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2967

" %s\n", interface, strerror(errno));

2968

} else {

2969

errno = argz_add(&interfaces_to_take_down,

2970

&interfaces_to_take_down_size,

2971

interface);

2972

if(errno != 0){

2973

perror_plus("argz_add");

2974

}

2975

}

2976

}

2977

}

2978

if(debug and (interfaces_to_take_down == NULL)){

2979

fprintf_plus(stderr, "No interfaces were brought up\n");

2980

}

2981

}

2982

2983

/* If we only got one interface, explicitly use only that one */

2984

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2985

if(debug){

2986

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2987

mc.interfaces);

2988

}

2989

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

1999

2990

}

2000

2991

2001

2992

if(quit_now){

2002

2993

goto end;

2003

2994

}

2004

2995

2005

ret = init_gnutls_global(pubkey, seckey);

2996

#if GNUTLS_VERSION_NUMBER >= 0x030606

2997

ret = init_gnutls_global(tls_pubkey, tls_privkey, dh_params_file, &mc);

2998

#elif GNUTLS_VERSION_NUMBER < 0x030600

2999

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

3000

#else

3001

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

3002

#endif

2006

3003

if(ret == -1){

2007

3004

fprintf_plus(stderr, "init_gnutls_global failed\n");

2008

3005

exitcode = EX_UNAVAILABLE;

2015

3012

goto end;

2016

3013

}

2017

3014

2018

if(mkdtemp(tempdir) == NULL){

3015

/* Try /run/tmp before /tmp */

3016

tempdir = mkdtemp(run_tempdir);

3017

if(tempdir == NULL and errno == ENOENT){

3018

if(debug){

3019

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

3020

run_tempdir, old_tempdir);

3021

}

3022

tempdir = mkdtemp(old_tempdir);

3023

}

3024

if(tempdir == NULL){

2019

3025

perror_plus("mkdtemp");

2020

3026

goto end;

2021

3027

}

2022

tempdir_created = true;

2023

3028

2024

3029

if(quit_now){

2025

3030

goto end;

2026

3031

}

2027

3032

2028

if(not init_gpgme(pubkey, seckey, tempdir)){

3033

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2029

3034

fprintf_plus(stderr, "init_gpgme failed\n");

2030

3035

exitcode = EX_UNAVAILABLE;

2031

3036

goto end;

2041

3046

/* Connect directly, do not use Zeroconf */

2042

3047

/* (Mainly meant for debugging) */

2043

3048

char *address = strrchr(connect_to, ':');

3049

2044

3050

if(address == NULL){

2045

3051

fprintf_plus(stderr, "No colon in address\n");

2046

3052

exitcode = EX_USAGE;

2051

3057

goto end;

2052

3058

}

2053

3059

2054

uint16_t port;

3060

in_port_t port;

2055

3061

errno = 0;

2056

3062

tmpmax = strtoimax(address+1, &tmp, 10);

2057

3063

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2058

or tmpmax != (uint16_t)tmpmax){

3064

or tmpmax != (in_port_t)tmpmax){

2059

3065

fprintf_plus(stderr, "Bad port number\n");

2060

3066

exitcode = EX_USAGE;

2061

3067

goto end;

2062

3068

}

2063

3069

2064

3070

if(quit_now){

2065

3071

goto end;

2066

3072

}

2067

3073

2068

port = (uint16_t)tmpmax;

3074

port = (in_port_t)tmpmax;

2069

3075

*address = '\0';

2070

3076

/* Colon in address indicates IPv6 */

2071

3077

int af;

2087

3093

}

2088

3094

2089

3095

while(not quit_now){

2090

ret = start_mandos_communication(address, port, if_index, af);

3096

ret = start_mandos_communication(address, port, if_index, af,

3097

&mc);

2091

3098

if(quit_now or ret == 0){

2092

3099

break;

2093

3100

}

2095

3102

fprintf_plus(stderr, "Retrying in %d seconds\n",

2096

3103

(int)retry_interval);

2097

3104

}

2098

sleep((int)retry_interval);

3105

sleep((unsigned int)retry_interval);

2099

3106

}

2100

3107

2101

if (not quit_now){

3108

if(not quit_now){

2102

3109

exitcode = EXIT_SUCCESS;

2103

3110

}

2104

3111

2119

3126

config.publish_domain = 0;

2120

3127

2121

3128

/* Allocate a new server */

2122

mc.server = avahi_server_new(avahi_simple_poll_get

2123

(mc.simple_poll), &config, NULL,

2124

NULL, &error);

3129

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3130

&config, NULL, NULL, &ret);

2125

3131

2126

3132

/* Free the Avahi configuration data */

2127

3133

avahi_server_config_free(&config);

2130

3136

/* Check if creating the Avahi server object succeeded */

2131

3137

if(mc.server == NULL){

2132

3138

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2133

avahi_strerror(error));

3139

avahi_strerror(ret));

2134

3140

exitcode = EX_UNAVAILABLE;

2135

3141

goto end;

2136

3142

}

2142

3148

/* Create the Avahi service browser */

2143

3149

sb = avahi_s_service_browser_new(mc.server, if_index,

2144

3150

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2145

NULL, 0, browse_callback, NULL);

3151

NULL, 0, browse_callback,

3152

(void *)&mc);

2146

3153

if(sb == NULL){

2147

3154

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2148

3155

avahi_strerror(avahi_server_errno(mc.server)));

2159

3166

if(debug){

2160

3167

fprintf_plus(stderr, "Starting Avahi loop search\n");

2161

3168

}

2162

2163

ret = avahi_loop_with_timeout(mc.simple_poll,

2164

(int)(retry_interval * 1000));

3169

3170

ret = avahi_loop_with_timeout(simple_poll,

3171

(int)(retry_interval * 1000), &mc);

2165

3172

if(debug){

2166

3173

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2167

3174

(ret == 0) ? "successfully" : "with error");

2170

3177

end:

2171

3178

2172

3179

if(debug){

2173

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3180

if(signal_received){

3181

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

3182

argv[0], signal_received,

3183

strsignal(signal_received));

3184

} else {

3185

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3186

}

2174

3187

}

2175

3188

2176

3189

/* Cleanup things */

3190

free(mc.interfaces);

3191

2177

3192

if(sb != NULL)

2178

3193

avahi_s_service_browser_free(sb);

2179

3194

2180

3195

if(mc.server != NULL)

2181

3196

avahi_server_free(mc.server);

2182

3197

2183

if(mc.simple_poll != NULL)

2184

avahi_simple_poll_free(mc.simple_poll);

3198

if(simple_poll != NULL)

3199

avahi_simple_poll_free(simple_poll);

2185

3200

2186

3201

if(gnutls_initialized){

2187

3202

gnutls_certificate_free_credentials(mc.cred);

2188

gnutls_global_deinit();

2189

3203

gnutls_dh_params_deinit(mc.dh_params);

2190

3204

}

2191

3205

2192

3206

if(gpgme_initialized){

2193

3207

gpgme_release(mc.ctx);

2194

3208

}

2195

3209

2196

3210

/* Cleans up the circular linked list of Mandos servers the client

2197

3211

has seen */

2198

3212

if(mc.current_server != NULL){

2199

3213

mc.current_server->prev->next = NULL;

2200

3214

while(mc.current_server != NULL){

2201

3215

server *next = mc.current_server->next;

3216

#ifdef __GNUC__

3217

#pragma GCC diagnostic push

3218

#pragma GCC diagnostic ignored "-Wcast-qual"

3219

#endif

3220

free((char *)(mc.current_server->ip));

3221

#ifdef __GNUC__

3222

#pragma GCC diagnostic pop

3223

#endif

2202

3224

free(mc.current_server);

2203

3225

mc.current_server = next;

2204

3226

}

2205

3227

}

2206

3228

2207

/* Re-raise priviliges */

3229

/* Re-raise privileges */

2208

3230

{

2209

errno = 0;

2210

ret = seteuid(0);

2211

if(ret == -1){

2212

perror_plus("seteuid");

2213

}

2214

/* Run network hooks */

2215

if(not run_network_hooks("stop", interface, delay)){

2216

goto end;

3231

ret = raise_privileges();

3232

if(ret != 0){

3233

errno = ret;

3234

perror_plus("Failed to raise privileges");

3235

} else {

3236

3237

/* Run network hooks */

3238

run_network_hooks("stop", interfaces_hooks != NULL ?

3239

interfaces_hooks : "", delay);

3240

3241

/* Take down the network interfaces which were brought up */

3242

{

3243

char *interface = NULL;

3244

while((interface = argz_next(interfaces_to_take_down,

3245

interfaces_to_take_down_size,

3246

interface))){

3247

ret = take_down_interface(interface);

3248

if(ret != 0){

3249

errno = ret;

3250

perror_plus("Failed to take down interface");

3251

}

3252

}

3253

if(debug and (interfaces_to_take_down == NULL)){

3254

fprintf_plus(stderr, "No interfaces needed to be taken"

3255

" down\n");

3256

}

3257

}

2217

3258

}

2218

3259

2219

/* Take down the network interface */

2220

if(take_down_interface and geteuid() == 0){

2221

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2222

if(ret == -1){

2223

perror_plus("ioctl SIOCGIFFLAGS");

2224

} else if(network.ifr_flags & IFF_UP){

2225

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2226

ret = ioctl(sd, SIOCSIFFLAGS, &network);

2227

if(ret == -1){

2228

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2229

}

2230

}

2231

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2232

if(ret == -1){

2233

perror_plus("close");

2234

}

3260

ret = lower_privileges_permanently();

3261

if(ret != 0){

3262

errno = ret;

3263

perror_plus("Failed to lower privileges permanently");

2235

3264

}

2236

3265

}

2237

/* Lower privileges permanently */

2238

errno = 0;

2239

ret = setuid(uid);

2240

if(ret == -1){

2241

perror_plus("setuid");

3266

3267

free(interfaces_to_take_down);

3268

free(interfaces_hooks);

3269

3270

void clean_dir_at(int base, const char * const dirname,

3271

uintmax_t level){

3272

struct dirent **direntries = NULL;

3273

int dret;

3274

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3275

O_RDONLY

3276

| O_NOFOLLOW

3277

| O_DIRECTORY

3278

| O_PATH));

3279

if(dir_fd == -1){

3280

perror_plus("open");

3281

return;

3282

}

3283

int numentries = scandirat(dir_fd, ".", &direntries,

3284

notdotentries, alphasort);

3285

if(numentries >= 0){

3286

for(int i = 0; i < numentries; i++){

3287

if(debug){

3288

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3289

dirname, direntries[i]->d_name);

3290

}

3291

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3292

if(dret == -1){

3293

if(errno == EISDIR){

3294

dret = unlinkat(dir_fd, direntries[i]->d_name,

3295

AT_REMOVEDIR);

3296

}

3297

if((dret == -1) and (errno == ENOTEMPTY)

3298

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3299

== 0) and (level == 0)){

3300

/* Recurse only in this special case */

3301

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3302

dret = 0;

3303

}

3304

if((dret == -1) and (errno != ENOENT)){

3305

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3306

direntries[i]->d_name, strerror(errno));

3307

}

3308

}

3309

free(direntries[i]);

3310

}

3311

3312

/* need to clean even if 0 because man page doesn't specify */

3313

free(direntries);

3314

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3315

if(dret == -1 and errno != ENOENT){

3316

perror_plus("rmdir");

3317

}

3318

} else {

3319

perror_plus("scandirat");

3320

}

3321

close(dir_fd);

2242

3322

}

2243

3323

2244

3324

/* Removes the GPGME temp directory and all files inside */

2245

if(tempdir_created){

2246

struct dirent **direntries = NULL;

2247

struct dirent *direntry = NULL;

2248

int numentries = scandir(tempdir, &direntries, notdotentries,

2249

alphasort);

2250

if (numentries > 0){

2251

for(int i = 0; i < numentries; i++){

2252

direntry = direntries[i];

2253

char *fullname = NULL;

2254

ret = asprintf(&fullname, "%s/%s", tempdir,

2255

direntry->d_name);

2256

if(ret < 0){

2257

perror_plus("asprintf");

2258

continue;

2259

}

2260

ret = remove(fullname);

2261

if(ret == -1){

2262

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2263

strerror(errno));

2264

}

2265

free(fullname);

2266

}

2267

}

2268

2269

/* need to clean even if 0 because man page doesn't specify */

2270

free(direntries);

2271

if (numentries == -1){

2272

perror_plus("scandir");

2273

}

2274

ret = rmdir(tempdir);

2275

if(ret == -1 and errno != ENOENT){

2276

perror_plus("rmdir");

2277

}

3325

if(tempdir != NULL){

3326

clean_dir_at(-1, tempdir, 0);

2278

3327

}

2279

3328

2280

3329

if(quit_now){