/mandos/trunk : revision 237.4.132

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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));

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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;

231

}

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;

306

}

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))

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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;

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}

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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;

330

}

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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*/

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,

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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

if(clock_settime(CLOCK_REALTIME, &keystat.st_mtim) != 0){

400

perror_plus("clock_settime");

401

}

402

ret = lower_privileges();

403

if(ret != 0){

404

errno = ret;

405

perror_plus("Failed to lower privileges");

406

}

407

} while(false);

408

263

409

rc = gpgme_data_new_from_fd(&pgp_data, fd);

264

410

if(rc != GPG_ERR_NO_ERROR){

265

411

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

267

413

return false;

268

414

}

269

415

270

rc = gpgme_op_import(mc.ctx, pgp_data);

416

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

271

417

if(rc != GPG_ERR_NO_ERROR){

272

418

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

273

419

gpgme_strsource(rc), gpgme_strerror(rc));

274

420

return false;

275

421

}

422

{

423

gpgme_import_result_t import_result

424

= gpgme_op_import_result(mc->ctx);

425

if((import_result->imported < 1

426

or import_result->not_imported > 0)

427

and import_result->unchanged == 0){

428

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

429

fprintf_plus(stderr,

430

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

431

import_result->considered);

432

fprintf_plus(stderr,

433

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

434

import_result->no_user_id);

435

fprintf_plus(stderr,

436

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

437

import_result->imported);

438

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

439

import_result->imported_rsa);

440

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

441

import_result->unchanged);

442

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

443

import_result->new_user_ids);

444

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

445

import_result->new_sub_keys);

446

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

447

import_result->new_signatures);

448

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

449

import_result->new_revocations);

450

fprintf_plus(stderr,

451

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

452

import_result->secret_read);

453

fprintf_plus(stderr,

454

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

455

import_result->secret_imported);

456

fprintf_plus(stderr,

457

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

458

import_result->secret_unchanged);

459

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

460

import_result->not_imported);

461

for(gpgme_import_status_t import_status

462

= import_result->imports;

463

import_status != NULL;

464

import_status = import_status->next){

465

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

466

import_status->fpr);

467

if(import_status->result != GPG_ERR_NO_ERROR){

468

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

469

gpgme_strsource(import_status->result),

470

gpgme_strerror(import_status->result));

471

}

472

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

473

fprintf_plus(stderr,

474

import_status->status & GPGME_IMPORT_NEW

475

? "The key was new.\n"

476

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

477

fprintf_plus(stderr,

478

import_status->status & GPGME_IMPORT_UID

479

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

480

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

481

fprintf_plus(stderr,

482

import_status->status & GPGME_IMPORT_SIG

483

? "The key contained new signatures.\n"

484

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

485

fprintf_plus(stderr,

486

import_status->status & GPGME_IMPORT_SUBKEY

487

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

488

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

489

fprintf_plus(stderr,

490

import_status->status & GPGME_IMPORT_SECRET

491

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

492

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

493

}

494

return false;

495

}

496

}

276

497

277

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

498

ret = close(fd);

278

499

if(ret == -1){

279

500

perror_plus("close");

280

501

}

317

538

}

318

539

319

540

/* Create new GPGME "context" */

320

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

541

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

321

542

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));

543

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

544

gpgme_strsource(rc), gpgme_strerror(rc));

325

545

return false;

326

546

}

327

547

336

556

* Decrypt OpenPGP data.

337

557

* Returns -1 on error

338

558

*/

559

__attribute__((nonnull, warn_unused_result))

339

560

static ssize_t pgp_packet_decrypt(const char *cryptotext,

340

561

size_t crypto_size,

341

char **plaintext){

562

char **plaintext,

563

mandos_context *mc){

342

564

gpgme_data_t dh_crypto, dh_plain;

343

565

gpgme_error_t rc;

344

566

ssize_t ret;

361

583

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

362

584

rc = gpgme_data_new(&dh_plain);

363

585

if(rc != GPG_ERR_NO_ERROR){

364

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

365

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

586

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

366

587

gpgme_strsource(rc), gpgme_strerror(rc));

367

588

gpgme_data_release(dh_crypto);

368

589

return -1;

370

591

371

592

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

372

593

data buffer */

373

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

594

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

374

595

if(rc != GPG_ERR_NO_ERROR){

375

596

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

376

597

gpgme_strsource(rc), gpgme_strerror(rc));

377

598

plaintext_length = -1;

378

599

if(debug){

379

600

gpgme_decrypt_result_t result;

380

result = gpgme_op_decrypt_result(mc.ctx);

601

result = gpgme_op_decrypt_result(mc->ctx);

381

602

if(result == NULL){

382

603

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

383

604

} 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);

605

if(result->unsupported_algorithm != NULL) {

606

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

607

result->unsupported_algorithm);

608

}

609

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

610

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

388

611

if(result->file_name != NULL){

389

612

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

390

613

}

391

gpgme_recipient_t recipient;

392

recipient = result->recipients;

393

while(recipient != NULL){

614

615

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

616

r = r->next){

394

617

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);

618

gpgme_pubkey_algo_name(r->pubkey_algo));

619

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

398

620

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

399

recipient->status == GPG_ERR_NO_SECKEY

400

? "No" : "Yes");

401

recipient = recipient->next;

621

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

402

622

}

403

623

}

404

624

}

460

680

return plaintext_length;

461

681

}

462

682

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;

683

__attribute__((warn_unused_result, const))

684

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

685

if(str == NULL)

686

return "(unknown)";

687

return str;

688

}

689

690

__attribute__((warn_unused_result))

691

static const char *safer_gnutls_strerror(int value){

692

const char *ret = gnutls_strerror(value);

693

return safe_string(ret);

469

694

}

470

695

471

696

/* GnuTLS log function callback */

697

__attribute__((nonnull))

472

698

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

473

699

const char* string){

474

700

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

475

701

}

476

702

703

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

477

704

static int init_gnutls_global(const char *pubkeyfilename,

478

const char *seckeyfilename){

705

const char *seckeyfilename,

706

const char *dhparamsfilename,

707

mandos_context *mc){

479

708

int ret;

480

709

481

710

if(debug){

482

711

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

483

712

}

484

713

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

714

if(debug){

493

715

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

494

716

* - GnuTLS manual

498

720

}

499

721

500

722

/* OpenPGP credentials */

501

ret = gnutls_certificate_allocate_credentials(&mc.cred);

723

ret = gnutls_certificate_allocate_credentials(&mc->cred);

502

724

if(ret != GNUTLS_E_SUCCESS){

503

725

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

504

726

safer_gnutls_strerror(ret));

505

gnutls_global_deinit();

506

727

return -1;

507

728

}

508

729

509

730

if(debug){

510

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

511

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

731

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

732

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

512

733

pubkeyfilename,

513

734

seckeyfilename);

514

735

}

515

736

737

#if GNUTLS_VERSION_NUMBER >= 0x030606

738

ret = gnutls_certificate_set_rawpk_key_file

739

(mc->cred, pubkeyfilename, seckeyfilename,

740

GNUTLS_X509_FMT_PEM, /* format */

741

NULL, /* pass */

742

/* key_usage */

743

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

744

NULL, /* names */

745

0, /* names_length */

746

/* privkey_flags */

747

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

748

0); /* pkcs11_flags */

749

#elif GNUTLS_VERSION_NUMBER < 0x030600

516

750

ret = gnutls_certificate_set_openpgp_key_file

517

(mc.cred, pubkeyfilename, seckeyfilename,

751

(mc->cred, pubkeyfilename, seckeyfilename,

518

752

GNUTLS_OPENPGP_FMT_BASE64);

753

#else

754

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

755

#endif

519

756

if(ret != GNUTLS_E_SUCCESS){

520

757

fprintf_plus(stderr,

521

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

758

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

522

759

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

523

760

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

524

761

safer_gnutls_strerror(ret));

526

763

}

527

764

528

765

/* GnuTLS server initialization */

529

ret = gnutls_dh_params_init(&mc.dh_params);

766

ret = gnutls_dh_params_init(&mc->dh_params);

530

767

if(ret != GNUTLS_E_SUCCESS){

531

768

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

532

769

" initialization: %s\n",

533

770

safer_gnutls_strerror(ret));

534

771

goto globalfail;

535

772

}

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);

773

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

774

if(dhparamsfilename != NULL){

775

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

776

do {

777

int dhpfile = open(dhparamsfilename, O_RDONLY);

778

if(dhpfile == -1){

779

perror_plus("open");

780

dhparamsfilename = NULL;

781

break;

782

}

783

size_t params_capacity = 0;

784

while(true){

785

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

786

(size_t)params.size,

787

(size_t)params_capacity);

788

if(params_capacity == 0){

789

perror_plus("incbuffer");

790

free(params.data);

791

params.data = NULL;

792

dhparamsfilename = NULL;

793

break;

794

}

795

ssize_t bytes_read = read(dhpfile,

796

params.data + params.size,

797

BUFFER_SIZE);

798

/* EOF */

799

if(bytes_read == 0){

800

break;

801

}

802

/* check bytes_read for failure */

803

if(bytes_read < 0){

804

perror_plus("read");

805

free(params.data);

806

params.data = NULL;

807

dhparamsfilename = NULL;

808

break;

809

}

810

params.size += (unsigned int)bytes_read;

811

}

812

ret = close(dhpfile);

813

if(ret == -1){

814

perror_plus("close");

815

}

816

if(params.data == NULL){

817

dhparamsfilename = NULL;

818

}

819

if(dhparamsfilename == NULL){

820

break;

821

}

822

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

823

GNUTLS_X509_FMT_PEM);

824

if(ret != GNUTLS_E_SUCCESS){

825

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

826

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

827

safer_gnutls_strerror(ret));

828

dhparamsfilename = NULL;

829

}

830

free(params.data);

831

} while(false);

832

}

833

if(dhparamsfilename == NULL){

834

if(mc->dh_bits == 0){

835

#if GNUTLS_VERSION_NUMBER < 0x030600

836

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

837

/* Try to read the private key file */

838

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

839

do {

840

int secfile = open(seckeyfilename, O_RDONLY);

841

if(secfile == -1){

842

perror_plus("open");

843

break;

844

}

845

size_t buffer_capacity = 0;

846

while(true){

847

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

848

(size_t)buffer.size,

849

(size_t)buffer_capacity);

850

if(buffer_capacity == 0){

851

perror_plus("incbuffer");

852

free(buffer.data);

853

buffer.data = NULL;

854

break;

855

}

856

ssize_t bytes_read = read(secfile,

857

buffer.data + buffer.size,

858

BUFFER_SIZE);

859

/* EOF */

860

if(bytes_read == 0){

861

break;

862

}

863

/* check bytes_read for failure */

864

if(bytes_read < 0){

865

perror_plus("read");

866

free(buffer.data);

867

buffer.data = NULL;

868

break;

869

}

870

buffer.size += (unsigned int)bytes_read;

871

}

872

close(secfile);

873

} while(false);

874

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

875

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

876

if(buffer.data != NULL){

877

{

878

gnutls_openpgp_privkey_t privkey = NULL;

879

ret = gnutls_openpgp_privkey_init(&privkey);

880

if(ret != GNUTLS_E_SUCCESS){

881

fprintf_plus(stderr, "Error initializing OpenPGP key"

882

" structure: %s",

883

safer_gnutls_strerror(ret));

884

free(buffer.data);

885

buffer.data = NULL;

886

} else {

887

ret = gnutls_openpgp_privkey_import

888

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

889

if(ret != GNUTLS_E_SUCCESS){

890

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

891

safer_gnutls_strerror(ret));

892

privkey = NULL;

893

}

894

free(buffer.data);

895

buffer.data = NULL;

896

if(privkey != NULL){

897

/* Use private key to suggest an appropriate

898

sec_param */

899

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

900

gnutls_openpgp_privkey_deinit(privkey);

901

if(debug){

902

fprintf_plus(stderr, "This OpenPGP key implies using"

903

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

904

safe_string(gnutls_sec_param_get_name

905

(sec_param)));

906

}

907

}

908

}

909

}

910

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

911

/* Err on the side of caution */

912

sec_param = GNUTLS_SEC_PARAM_ULTRA;

913

if(debug){

914

fprintf_plus(stderr, "Falling back to security parameter"

915

" \"%s\"\n",

916

safe_string(gnutls_sec_param_get_name

917

(sec_param)));

918

}

919

}

920

}

921

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

922

if(uret != 0){

923

mc->dh_bits = uret;

924

if(debug){

925

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

926

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

927

safe_string(gnutls_sec_param_get_name

928

(sec_param)),

929

mc->dh_bits);

930

}

931

} else {

932

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

933

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

934

safe_string(gnutls_sec_param_get_name

935

(sec_param)),

936

safer_gnutls_strerror(ret));

937

goto globalfail;

938

}

939

#endif

940

} else { /* dh_bits != 0 */

941

if(debug){

942

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

943

mc->dh_bits);

944

}

945

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

946

if(ret != GNUTLS_E_SUCCESS){

947

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

948

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

949

safer_gnutls_strerror(ret));

950

goto globalfail;

951

}

952

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

953

}

954

}

544

955

545

956

return 0;

546

957

547

958

globalfail:

548

959

549

gnutls_certificate_free_credentials(mc.cred);

550

gnutls_global_deinit();

551

gnutls_dh_params_deinit(mc.dh_params);

960

gnutls_certificate_free_credentials(mc->cred);

961

gnutls_dh_params_deinit(mc->dh_params);

552

962

return -1;

553

963

}

554

964

555

static int init_gnutls_session(gnutls_session_t *session){

965

__attribute__((nonnull, warn_unused_result))

966

static int init_gnutls_session(gnutls_session_t *session,

967

mandos_context *mc){

556

968

int ret;

557

969

/* GnuTLS session creation */

558

970

do {

559

ret = gnutls_init(session, GNUTLS_SERVER);

971

ret = gnutls_init(session, (GNUTLS_SERVER

972

#if GNUTLS_VERSION_NUMBER >= 0x030506

973

| GNUTLS_NO_TICKETS

974

#endif

975

#if GNUTLS_VERSION_NUMBER >= 0x030606

976

| GNUTLS_ENABLE_RAWPK

977

#endif

978

));

560

979

if(quit_now){

561

980

return -1;

562

981

}

570

989

{

571

990

const char *err;

572

991

do {

573

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

992

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

574

993

if(quit_now){

575

994

gnutls_deinit(*session);

576

995

return -1;

587

1006

588

1007

do {

589

1008

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

590

mc.cred);

1009

mc->cred);

591

1010

if(quit_now){

592

1011

gnutls_deinit(*session);

593

1012

return -1;

603

1022

/* ignore client certificate if any. */

604

1023

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

605

1024

606

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

607

608

1025

return 0;

609

1026

}

610

1027

612

1029

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

613

1030

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

614

1031

1032

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

1033

__attribute__((nonnull, warn_unused_result))

1034

static bool add_delete_local_route(const bool add,

1035

const char *address,

1036

AvahiIfIndex if_index){

1037

int ret;

1038

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

1039

char add_arg[] = "add";

1040

char delete_arg[] = "delete";

1041

char debug_flag[] = "--debug";

1042

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1043

if(pluginhelperdir == NULL){

1044

if(debug){

1045

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1046

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

1047

}

1048

return false;

1049

}

1050

1051

char interface[IF_NAMESIZE];

1052

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

1053

perror_plus("if_indextoname");

1054

return false;

1055

}

1056

1057

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

1058

if(devnull == -1){

1059

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

1060

return false;

1061

}

1062

pid_t pid = fork();

1063

if(pid == 0){

1064

/* Child */

1065

/* Raise privileges */

1066

errno = raise_privileges_permanently();

1067

if(errno != 0){

1068

perror_plus("Failed to raise privileges");

1069

/* _exit(EX_NOPERM); */

1070

} else {

1071

/* Set group */

1072

errno = 0;

1073

ret = setgid(0);

1074

if(ret == -1){

1075

perror_plus("setgid");

1076

close(devnull);

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

close(devnull);

1085

_exit(EX_NOPERM);

1086

}

1087

}

1088

ret = dup2(devnull, STDIN_FILENO);

1089

if(ret == -1){

1090

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

1091

close(devnull);

1092

_exit(EX_OSERR);

1093

}

1094

ret = close(devnull);

1095

if(ret == -1){

1096

perror_plus("close");

1097

}

1098

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1099

if(ret == -1){

1100

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

1101

_exit(EX_OSERR);

1102

}

1103

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

1104

O_RDONLY

1105

| O_DIRECTORY

1106

| O_PATH

1107

| O_CLOEXEC));

1108

if(helperdir_fd == -1){

1109

perror_plus("open");

1110

_exit(EX_UNAVAILABLE);

1111

}

1112

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

1113

helper, O_RDONLY));

1114

if(helper_fd == -1){

1115

perror_plus("openat");

1116

close(helperdir_fd);

1117

_exit(EX_UNAVAILABLE);

1118

}

1119

close(helperdir_fd);

1120

#ifdef __GNUC__

1121

#pragma GCC diagnostic push

1122

#pragma GCC diagnostic ignored "-Wcast-qual"

1123

#endif

1124

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

1125

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

1126

interface, debug ? debug_flag : NULL, NULL },

1127

environ) == -1){

1128

#ifdef __GNUC__

1129

#pragma GCC diagnostic pop

1130

#endif

1131

perror_plus("fexecve");

1132

_exit(EXIT_FAILURE);

1133

}

1134

}

1135

if(pid == -1){

1136

perror_plus("fork");

1137

close(devnull);

1138

return false;

1139

}

1140

ret = close(devnull);

1141

if(ret == -1){

1142

perror_plus("close");

1143

}

1144

int status;

1145

pid_t pret = -1;

1146

errno = 0;

1147

do {

1148

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

1149

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

1150

int errno_raising = 0;

1151

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

1152

errno_raising = errno;

1153

perror_plus("Failed to raise privileges in order to"

1154

" kill helper program");

1155

}

1156

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

1157

perror_plus("kill");

1158

}

1159

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

1160

perror_plus("Failed to lower privileges after killing"

1161

" helper program");

1162

}

1163

return false;

1164

}

1165

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

1166

if(pret == -1){

1167

perror_plus("waitpid");

1168

return false;

1169

}

1170

if(WIFEXITED(status)){

1171

if(WEXITSTATUS(status) != 0){

1172

fprintf_plus(stderr, "Error: iprouteadddel exited"

1173

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

1174

return false;

1175

}

1176

return true;

1177

}

1178

if(WIFSIGNALED(status)){

1179

fprintf_plus(stderr, "Error: iprouteadddel died by"

1180

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

1181

return false;

1182

}

1183

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

1184

return false;

1185

}

1186

1187

__attribute__((nonnull, warn_unused_result))

1188

static bool add_local_route(const char *address,

1189

AvahiIfIndex if_index){

1190

if(debug){

1191

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

1192

}

1193

return add_delete_local_route(true, address, if_index);

1194

}

1195

1196

__attribute__((nonnull, warn_unused_result))

1197

static bool delete_local_route(const char *address,

1198

AvahiIfIndex if_index){

1199

if(debug){

1200

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

1201

}

1202

return add_delete_local_route(false, address, if_index);

1203

}

1204

615

1205

/* Called when a Mandos server is found */

616

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

1206

__attribute__((nonnull, warn_unused_result))

1207

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

617

1208

AvahiIfIndex if_index,

618

int af){

1209

int af, mandos_context *mc){

619

1210

int ret, tcp_sd = -1;

620

1211

ssize_t sret;

621

union {

622

struct sockaddr_in in;

623

struct sockaddr_in6 in6;

624

} to;

1212

struct sockaddr_storage to;

625

1213

char *buffer = NULL;

626

1214

char *decrypted_buffer = NULL;

627

1215

size_t buffer_length = 0;

630

1218

int retval = -1;

631

1219

gnutls_session_t session;

632

1220

int pf; /* Protocol family */

1221

bool route_added = false;

633

1222

634

1223

errno = 0;

635

1224

651

1240

return -1;

652

1241

}

653

1242

654

ret = init_gnutls_session(&session);

1243

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

1244

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

1245

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

1246

bool match = false;

1247

{

1248

char *interface = NULL;

1249

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

1250

mc->interfaces_size,

1251

interface))){

1252

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

1253

match = true;

1254

break;

1255

}

1256

}

1257

}

1258

if(not match){

1259

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

1260

connect to the server */

1261

if(debug){

1262

char interface[IF_NAMESIZE];

1263

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

1264

perror_plus("if_indextoname");

1265

} else {

1266

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

1267

" \"%s\"\n",

1268

if_indextoname((unsigned int)if_index,

1269

interface));

1270

}

1271

}

1272

return -1;

1273

}

1274

}

1275

1276

ret = init_gnutls_session(&session, mc);

655

1277

if(ret != 0){

656

1278

return -1;

657

1279

}

658

1280

659

1281

if(debug){

660

1282

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

661

PRIu16 "\n", ip, port);

1283

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

662

1284

}

663

1285

664

tcp_sd = socket(pf, SOCK_STREAM, 0);

1286

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

665

1287

if(tcp_sd < 0){

666

1288

int e = errno;

667

1289

perror_plus("socket");

674

1296

goto mandos_end;

675

1297

}

676

1298

677

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

678

1299

if(af == AF_INET6){

679

to.in6.sin6_family = (sa_family_t)af;

680

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

1300

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

1301

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

1302

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

681

1303

} else { /* IPv4 */

682

to.in.sin_family = (sa_family_t)af;

683

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

1304

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

1305

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

1306

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

684

1307

}

685

1308

if(ret < 0 ){

686

1309

int e = errno;

695

1318

goto mandos_end;

696

1319

}

697

1320

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*/

1321

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

1322

if(IN6_IS_ADDR_LINKLOCAL

1323

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

705

1324

if(if_index == AVAHI_IF_UNSPEC){

706

1325

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

707

1326

" incomplete without a network interface\n");

709

1328

goto mandos_end;

710

1329

}

711

1330

/* Set the network interface number as scope */

712

to.in6.sin6_scope_id = (uint32_t)if_index;

1331

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

713

1332

}

714

1333

} else {

715

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

716

-Wconversion and

717

-Wunreachable-code */

1334

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

718

1335

}

719

1336

720

1337

if(quit_now){

728

1345

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

729

1346

perror_plus("if_indextoname");

730

1347

} else {

731

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

732

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

1348

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

1349

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

733

1350

}

734

1351

} else {

735

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

736

ip, port);

1352

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

1353

ip, (uintmax_t)port);

737

1354

}

738

1355

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

739

1356

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;

1357

if(af == AF_INET6){

1358

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

1359

sizeof(struct sockaddr_in6),

1360

addrstr, sizeof(addrstr), NULL, 0,

1361

NI_NUMERICHOST);

1362

} else {

1363

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

1364

sizeof(struct sockaddr_in),

1365

addrstr, sizeof(addrstr), NULL, 0,

1366

NI_NUMERICHOST);

1367

}

1368

if(ret == EAI_SYSTEM){

1369

perror_plus("getnameinfo");

1370

} else if(ret != 0) {

1371

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

1372

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

1373

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

1374

}

1375

}

1376

1377

if(quit_now){

1378

errno = EINTR;

1379

goto mandos_end;

1380

}

1381

1382

while(true){

1383

if(af == AF_INET6){

1384

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

1385

sizeof(struct sockaddr_in6));

1386

} else {

1387

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

1388

sizeof(struct sockaddr_in));

1389

}

1390

if(ret < 0){

1391

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

1392

and if_index != AVAHI_IF_UNSPEC

1393

and connect_to == NULL

1394

and not route_added and

1395

((af == AF_INET6 and not

1396

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1397

&to)->sin6_addr)))

1398

or (af == AF_INET and

1399

/* Not a a IPv4LL address */

1400

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

1401

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

1402

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

1403

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

1404

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

1405

connect to a Mandos server announced by Avahi on a server

1406

host with a global address. Work around this by retrying

1407

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

1408

1409

Avahi bug reference:

1410

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

1411

https://bugs.debian.org/587961

1412

*/

1413

if(debug){

1414

fprintf_plus(stderr, "Mandos server unreachable, trying"

1415

" direct route\n");

1416

}

1417

int e = errno;

1418

route_added = add_local_route(ip, if_index);

1419

if(route_added){

1420

continue;

1421

}

1422

errno = e;

1423

}

1424

if(errno != ECONNREFUSED or debug){

1425

int e = errno;

1426

perror_plus("connect");

1427

errno = e;

1428

}

1429

goto mandos_end;

1430

}

1431

1432

if(quit_now){

1433

errno = EINTR;

1434

goto mandos_end;

1435

}

1436

break;

779

1437

}

780

1438

781

1439

const char *out = mandos_protocol_version;

817

1475

goto mandos_end;

818

1476

}

819

1477

820

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

821

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1478

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

1479

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

1480

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

1481

gnutls_transport_set_ptr(session,

1482

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

822

1483

823

1484

if(quit_now){

824

1485

errno = EINTR;

929

1590

if(buffer_length > 0){

930

1591

ssize_t decrypted_buffer_size;

931

1592

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

932

&decrypted_buffer);

1593

&decrypted_buffer, mc);

933

1594

if(decrypted_buffer_size >= 0){

934

1595

1596

clearerr(stdout);

935

1597

written = 0;

936

1598

while(written < (size_t) decrypted_buffer_size){

937

1599

if(quit_now){

953

1615

}

954

1616

written += (size_t)ret;

955

1617

}

1618

ret = fflush(stdout);

1619

if(ret != 0){

1620

int e = errno;

1621

if(debug){

1622

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

1623

strerror(errno));

1624

}

1625

errno = e;

1626

goto mandos_end;

1627

}

956

1628

retval = 0;

957

1629

}

958

1630

}

961

1633

962

1634

mandos_end:

963

1635

{

1636

if(route_added){

1637

if(not delete_local_route(ip, if_index)){

1638

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

1639

" interface %d", ip, if_index);

1640

}

1641

}

964

1642

int e = errno;

965

1643

free(decrypted_buffer);

966

1644

free(buffer);

967

1645

if(tcp_sd >= 0){

968

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

1646

ret = close(tcp_sd);

969

1647

}

970

1648

if(ret == -1){

971

1649

if(e == 0){

996

1674

AVAHI_GCC_UNUSED AvahiStringList *txt,

997

1675

AVAHI_GCC_UNUSED AvahiLookupResultFlags

998

1676

flags,

999

AVAHI_GCC_UNUSED void* userdata){

1000

assert(r);

1677

void *mc){

1678

if(r == NULL){

1679

return;

1680

}

1001

1681

1002

1682

/* Called whenever a service has been resolved successfully or

1003

1683

timed out */

1004

1684

1005

1685

if(quit_now){

1686

avahi_s_service_resolver_free(r);

1006

1687

return;

1007

1688

}

1008

1689

1012

1693

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

1013

1694

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

1014

1695

domain,

1015

avahi_strerror(avahi_server_errno(mc.server)));

1696

avahi_strerror(avahi_server_errno

1697

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

1016

1698

break;

1017

1699

1018

1700

case AVAHI_RESOLVER_FOUND:

1024

1706

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

1025

1707

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

1026

1708

}

1027

int ret = start_mandos_communication(ip, port, interface,

1028

avahi_proto_to_af(proto));

1709

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

1710

interface,

1711

avahi_proto_to_af(proto),

1712

mc);

1029

1713

if(ret == 0){

1030

avahi_simple_poll_quit(mc.simple_poll);

1714

avahi_simple_poll_quit(simple_poll);

1031

1715

} else {

1032

ret = add_server(ip, port, interface,

1033

avahi_proto_to_af(proto));

1716

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

1717

avahi_proto_to_af(proto),

1718

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

1719

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

1720

" list\n", name);

1721

}

1034

1722

}

1035

1723

}

1036

1724

}

1046

1734

const char *domain,

1047

1735

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1048

1736

flags,

1049

AVAHI_GCC_UNUSED void* userdata){

1050

assert(b);

1737

void *mc){

1738

if(b == NULL){

1739

return;

1740

}

1051

1741

1052

1742

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

1053

1743

is removed from the LAN */

1061

1751

case AVAHI_BROWSER_FAILURE:

1062

1752

1063

1753

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

1064

avahi_strerror(avahi_server_errno(mc.server)));

1065

avahi_simple_poll_quit(mc.simple_poll);

1754

avahi_strerror(avahi_server_errno

1755

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

1756

avahi_simple_poll_quit(simple_poll);

1066

1757

return;

1067

1758

1068

1759

case AVAHI_BROWSER_NEW:

1071

1762

the callback function is called the Avahi server will free the

1072

1763

resolver for us. */

1073

1764

1074

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

1075

name, type, domain, protocol, 0,

1076

resolve_callback, NULL) == NULL)

1765

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

1766

interface, protocol, name, type,

1767

domain, protocol, 0,

1768

resolve_callback, mc) == NULL)

1077

1769

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

1078

1770

" %s\n", name,

1079

avahi_strerror(avahi_server_errno(mc.server)));

1771

avahi_strerror(avahi_server_errno

1772

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

1080

1773

break;

1081

1774

1082

1775

case AVAHI_BROWSER_REMOVE:

1101

1794

signal_received = sig;

1102

1795

int old_errno = errno;

1103

1796

/* set main loop to exit */

1104

if(mc.simple_poll != NULL){

1105

avahi_simple_poll_quit(mc.simple_poll);

1797

if(simple_poll != NULL){

1798

avahi_simple_poll_quit(simple_poll);

1106

1799

}

1107

1800

errno = old_errno;

1108

1801

}

1109

1802

1803

__attribute__((nonnull, warn_unused_result))

1110

1804

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

1111

1805

int ret;

1806

int old_errno;

1112

1807

1113

1808

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

1114

1809

if(s < 0){

1810

old_errno = errno;

1115

1811

perror_plus("socket");

1812

errno = old_errno;

1116

1813

return false;

1117

1814

}

1118

strcpy(ifr->ifr_name, ifname);

1815

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

1816

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

1119

1817

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1120

1818

if(ret == -1){

1121

1819

if(debug){

1820

old_errno = errno;

1122

1821

perror_plus("ioctl SIOCGIFFLAGS");

1822

errno = old_errno;

1823

}

1824

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

1825

old_errno = errno;

1826

perror_plus("close");

1827

errno = old_errno;

1123

1828

}

1124

1829

return false;

1125

1830

}

1831

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

1832

old_errno = errno;

1833

perror_plus("close");

1834

errno = old_errno;

1835

}

1126

1836

return true;

1127

1837

}

1128

1838

1839

__attribute__((nonnull, warn_unused_result))

1129

1840

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

1130

1841

1131

1842

/* Reject the loopback device */

1173

1884

* corresponds to an acceptable network device.

1174

1885

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

1175

1886

*/

1887

__attribute__((nonnull, warn_unused_result))

1176

1888

int good_interface(const struct dirent *if_entry){

1177

1889

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

1178

1890

return 0;

1194

1906

}

1195

1907

1196

1908

/*

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

1909

* This function determines if a network interface is up.

1910

*/

1911

__attribute__((nonnull, warn_unused_result))

1912

bool interface_is_up(const char *interface){

1913

struct ifreq ifr;

1914

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

1915

if(debug){

1916

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

1917

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

1918

}

1919

return false;

1920

}

1921

1922

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

1923

}

1924

1925

/*

1926

* This function determines if a network interface is running

1927

*/

1928

__attribute__((nonnull, warn_unused_result))

1929

bool interface_is_running(const char *interface){

1930

struct ifreq ifr;

1931

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

1932

if(debug){

1933

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

1934

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

1935

}

1936

return false;

1937

}

1938

1939

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

1940

}

1941

1942

__attribute__((nonnull, pure, warn_unused_result))

1239

1943

int notdotentries(const struct dirent *direntry){

1240

1944

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

1241

1945

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

1248

1952

}

1249

1953

1250

1954

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

1955

__attribute__((nonnull, warn_unused_result))

1251

1956

int runnable_hook(const struct dirent *direntry){

1252

1957

int ret;

1253

1958

size_t sret;

1261

1966

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

1262

1967

"abcdefghijklmnopqrstuvwxyz"

1263

1968

"0123456789"

1264

"_-");

1969

"_.-");

1265

1970

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

1266

1971

/* Contains non-allowed characters */

1267

1972

if(debug){

1271

1976

return 0;

1272

1977

}

1273

1978

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);

1979

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

1282

1980

if(ret == -1){

1283

1981

if(debug){

1284

1982

perror_plus("Could not stat hook");

1301

1999

}

1302

2000

return 0;

1303

2001

}

2002

if(debug){

2003

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

2004

direntry->d_name);

2005

}

1304

2006

return 1;

1305

2007

}

1306

2008

1307

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

2009

__attribute__((nonnull, warn_unused_result))

2010

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

2011

mandos_context *mc){

1308

2012

int ret;

1309

2013

struct timespec now;

1310

2014

struct timespec waited_time;

1311

2015

intmax_t block_time;

1312

2016

1313

2017

while(true){

1314

if(mc.current_server == NULL){

1315

if (debug){

2018

if(mc->current_server == NULL){

2019

if(debug){

1316

2020

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

1317

2021

" No timeout!\n");

1318

2022

}

1319

2023

ret = avahi_simple_poll_iterate(s, -1);

1320

2024

} else {

1321

if (debug){

2025

if(debug){

1322

2026

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

1323

2027

" it, or wait\n");

1324

2028

}

1331

2035

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

1332

2036

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

1333

2037

waited_time.tv_sec = (now.tv_sec

1334

- mc.current_server->last_seen.tv_sec);

2038

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

1335

2039

waited_time.tv_nsec = (now.tv_nsec

1336

- mc.current_server->last_seen.tv_nsec);

2040

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

1337

2041

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

1338

2042

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

1339

2043

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

1341

2045

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

1342

2046

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

1343

2047

1344

if (debug){

2048

if(debug){

1345

2049

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

1346

2050

block_time);

1347

2051

}

1348

2052

1349

2053

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);

2054

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

2055

mc->current_server->port,

2056

mc->current_server->if_index,

2057

mc->current_server->af, mc);

1354

2058

if(ret == 0){

1355

avahi_simple_poll_quit(mc.simple_poll);

2059

avahi_simple_poll_quit(s);

1356

2060

return 0;

1357

2061

}

1358

2062

ret = clock_gettime(CLOCK_MONOTONIC,

1359

&mc.current_server->last_seen);

2063

&mc->current_server->last_seen);

1360

2064

if(ret == -1){

1361

2065

perror_plus("clock_gettime");

1362

2066

return -1;

1363

2067

}

1364

mc.current_server = mc.current_server->next;

2068

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

1365

2069

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

1366

2070

servers, but don't block */

1367

2071

}

1369

2073

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

1370

2074

}

1371

2075

if(ret != 0){

1372

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

2076

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

1373

2077

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

1374

2078

}

1375

2079

}

1376

2080

}

1377

2081

}

1378

2082

1379

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

2083

__attribute__((nonnull))

2084

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

1380

2085

const float delay){

1381

struct dirent **direntries;

1382

struct dirent *direntry;

1383

int ret;

1384

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

1385

alphasort);

2086

struct dirent **direntries = NULL;

2087

if(hookdir_fd == -1){

2088

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2089

| O_CLOEXEC);

2090

if(hookdir_fd == -1){

2091

if(errno == ENOENT){

2092

if(debug){

2093

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

2094

" found\n", hookdir);

2095

}

2096

} else {

2097

perror_plus("open");

2098

}

2099

return;

2100

}

2101

}

2102

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

2103

if(devnull == -1){

2104

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

2105

return;

2106

}

2107

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

2108

runnable_hook, alphasort);

1386

2109

if(numhooks == -1){

1387

2110

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){

2111

close(devnull);

2112

return;

2113

}

2114

struct dirent *direntry;

2115

int ret;

2116

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

2117

direntry = direntries[i];

2118

if(debug){

2119

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

2120

direntry->d_name);

2121

}

2122

pid_t hook_pid = fork();

2123

if(hook_pid == 0){

2124

/* Child */

2125

/* Raise privileges */

2126

errno = raise_privileges_permanently();

2127

if(errno != 0){

2128

perror_plus("Failed to raise privileges");

2129

_exit(EX_NOPERM);

2130

}

2131

/* Set group */

2132

errno = 0;

2133

ret = setgid(0);

2134

if(ret == -1){

2135

perror_plus("setgid");

2136

_exit(EX_NOPERM);

2137

}

2138

/* Reset supplementary groups */

2139

errno = 0;

2140

ret = setgroups(0, NULL);

2141

if(ret == -1){

2142

perror_plus("setgroups");

2143

_exit(EX_NOPERM);

2144

}

2145

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

2146

if(ret == -1){

2147

perror_plus("setenv");

2148

_exit(EX_OSERR);

2149

}

2150

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

2151

if(ret == -1){

2152

perror_plus("setenv");

2153

_exit(EX_OSERR);

2154

}

2155

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

2156

if(ret == -1){

2157

perror_plus("setenv");

2158

_exit(EX_OSERR);

2159

}

2160

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

2161

if(ret == -1){

2162

perror_plus("setenv");

2163

_exit(EX_OSERR);

2164

}

2165

char *delaystring;

2166

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

2167

if(ret == -1){

1395

2168

perror_plus("asprintf");

1396

continue;

2169

_exit(EX_OSERR);

1397

2170

}

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

}

2171

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

2172

if(ret == -1){

1436

2173

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;

2174

perror_plus("setenv");

2175

_exit(EX_OSERR);

2176

}

2177

free(delaystring);

2178

if(connect_to != NULL){

2179

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

2180

if(ret == -1){

2181

perror_plus("setenv");

2182

_exit(EX_OSERR);

2183

}

2184

}

2185

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

2186

direntry->d_name,

2187

O_RDONLY));

2188

if(hook_fd == -1){

2189

perror_plus("openat");

2190

_exit(EXIT_FAILURE);

2191

}

2192

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

2193

perror_plus("close");

2194

_exit(EXIT_FAILURE);

2195

}

2196

ret = dup2(devnull, STDIN_FILENO);

2197

if(ret == -1){

2198

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

2199

_exit(EX_OSERR);

2200

}

2201

ret = close(devnull);

2202

if(ret == -1){

2203

perror_plus("close");

2204

_exit(EX_OSERR);

2205

}

2206

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2207

if(ret == -1){

2208

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

2209

_exit(EX_OSERR);

2210

}

2211

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

2212

environ) == -1){

2213

perror_plus("fexecve");

2214

_exit(EXIT_FAILURE);

2215

}

2216

} else {

2217

if(hook_pid == -1){

2218

perror_plus("fork");

2219

free(direntry);

2220

continue;

2221

}

2222

int status;

2223

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

2224

perror_plus("waitpid");

2225

free(direntry);

2226

continue;

2227

}

2228

if(WIFEXITED(status)){

2229

if(WEXITSTATUS(status) != 0){

2230

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

2231

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

2232

WEXITSTATUS(status));

2233

free(direntry);

2234

continue;

2235

}

2236

} else if(WIFSIGNALED(status)){

2237

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

2238

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

2239

WTERMSIG(status));

2240

free(direntry);

2241

continue;

2242

} else {

2243

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

2244

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

2245

free(direntry);

2246

continue;

2247

}

2248

}

2249

if(debug){

2250

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

2251

direntry->d_name);

2252

}

2253

free(direntry);

2254

}

2255

free(direntries);

2256

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

2257

perror_plus("close");

2258

} else {

2259

hookdir_fd = -1;

2260

}

2261

close(devnull);

2262

}

2263

2264

__attribute__((nonnull, warn_unused_result))

2265

int bring_up_interface(const char *const interface,

2266

const float delay){

2267

int old_errno = errno;

2268

int ret;

2269

struct ifreq network;

2270

unsigned int if_index = if_nametoindex(interface);

2271

if(if_index == 0){

2272

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

2273

errno = old_errno;

2274

return ENXIO;

2275

}

2276

2277

if(quit_now){

2278

errno = old_errno;

2279

return EINTR;

2280

}

2281

2282

if(not interface_is_up(interface)){

2283

int ret_errno = 0;

2284

int ioctl_errno = 0;

2285

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

2286

ret_errno = errno;

2287

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

2288

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

2289

errno = old_errno;

2290

return ret_errno;

2291

}

2292

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

2293

2294

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

2295

if(sd == -1){

2296

ret_errno = errno;

2297

perror_plus("socket");

2298

errno = old_errno;

2299

return ret_errno;

2300

}

2301

2302

if(quit_now){

2303

ret = close(sd);

2304

if(ret == -1){

2305

perror_plus("close");

2306

}

2307

errno = old_errno;

2308

return EINTR;

2309

}

2310

2311

if(debug){

2312

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

2313

interface);

2314

}

2315

2316

/* Raise privileges */

2317

ret_errno = raise_privileges();

2318

if(ret_errno != 0){

2319

errno = ret_errno;

2320

perror_plus("Failed to raise privileges");

2321

}

2322

2323

#ifdef __linux__

2324

int ret_linux;

2325

bool restore_loglevel = false;

2326

if(ret_errno == 0){

2327

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2328

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

2329

ret_linux = klogctl(8, NULL, 5);

2330

if(ret_linux == -1){

2331

perror_plus("klogctl");

2332

} else {

2333

restore_loglevel = true;

2334

}

2335

}

2336

#endif /* __linux__ */

2337

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

2338

ioctl_errno = errno;

2339

#ifdef __linux__

2340

if(restore_loglevel){

2341

ret_linux = klogctl(7, NULL, 0);

2342

if(ret_linux == -1){

2343

perror_plus("klogctl");

2344

}

2345

}

2346

#endif /* __linux__ */

2347

2348

/* If raise_privileges() succeeded above */

2349

if(ret_errno == 0){

2350

/* Lower privileges */

2351

ret_errno = lower_privileges();

2352

if(ret_errno != 0){

2353

errno = ret_errno;

2354

perror_plus("Failed to lower privileges");

2355

}

2356

}

2357

2358

/* Close the socket */

2359

ret = close(sd);

2360

if(ret == -1){

2361

perror_plus("close");

2362

}

2363

2364

if(ret_setflags == -1){

2365

errno = ioctl_errno;

2366

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2367

errno = old_errno;

2368

return ioctl_errno;

2369

}

2370

} else if(debug){

2371

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

2372

interface);

2373

}

2374

2375

/* Sleep checking until interface is running.

2376

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

2377

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

2378

if(interface_is_running(interface)){

2379

break;

2380

}

2381

struct timespec sleeptime = { .tv_nsec = 250000000 };

2382

ret = nanosleep(&sleeptime, NULL);

2383

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

2384

perror_plus("nanosleep");

2385

}

2386

}

2387

2388

errno = old_errno;

2389

return 0;

2390

}

2391

2392

__attribute__((nonnull, warn_unused_result))

2393

int take_down_interface(const char *const interface){

2394

int old_errno = errno;

2395

struct ifreq network;

2396

unsigned int if_index = if_nametoindex(interface);

2397

if(if_index == 0){

2398

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

2399

errno = old_errno;

2400

return ENXIO;

2401

}

2402

if(interface_is_up(interface)){

2403

int ret_errno = 0;

2404

int ioctl_errno = 0;

2405

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

2406

ret_errno = errno;

2407

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

2408

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

2409

errno = old_errno;

2410

return ret_errno;

2411

}

2412

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

2413

2414

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

2415

if(sd == -1){

2416

ret_errno = errno;

2417

perror_plus("socket");

2418

errno = old_errno;

2419

return ret_errno;

2420

}

2421

2422

if(debug){

2423

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

2424

interface);

2425

}

2426

2427

/* Raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

2432

}

2433

2434

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

2435

ioctl_errno = errno;

2436

2437

/* If raise_privileges() succeeded above */

2438

if(ret_errno == 0){

2439

/* Lower privileges */

2440

ret_errno = lower_privileges();

2441

if(ret_errno != 0){

2442

errno = ret_errno;

2443

perror_plus("Failed to lower privileges");

2444

}

2445

}

2446

2447

/* Close the socket */

2448

int ret = close(sd);

2449

if(ret == -1){

2450

perror_plus("close");

2451

}

2452

2453

if(ret_setflags == -1){

2454

errno = ioctl_errno;

2455

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2456

errno = old_errno;

2457

return ioctl_errno;

2458

}

2459

} else if(debug){

2460

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

2461

interface);

2462

}

2463

2464

errno = old_errno;

2465

return 0;

1475

2466

}

1476

2467

1477

2468

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

2469

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

2470

#if GNUTLS_VERSION_NUMBER >= 0x030606

2471

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

2472

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

2473

":%PROFILE_ULTRA",

2474

#elif GNUTLS_VERSION_NUMBER < 0x030600

2475

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

2476

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

2477

#else

2478

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

2479

#endif

2480

.current_server = NULL, .interfaces = NULL,

2481

.interfaces_size = 0 };

1478

2482

AvahiSServiceBrowser *sb = NULL;

1479

int error;

2483

error_t ret_errno;

1480

2484

int ret;

1481

2485

intmax_t tmpmax;

1482

2486

char *tmp;

1483

2487

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;

2488

char *interfaces_to_take_down = NULL;

2489

size_t interfaces_to_take_down_size = 0;

2490

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

2491

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

2492

char *tempdir = NULL;

1492

2493

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1493

2494

const char *seckey = PATHDIR "/" SECKEY;

1494

2495

const char *pubkey = PATHDIR "/" PUBKEY;

2496

#if GNUTLS_VERSION_NUMBER >= 0x030606

2497

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2498

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2499

#endif

2500

const char *dh_params_file = NULL;

2501

char *interfaces_hooks = NULL;

1495

2502

1496

2503

bool gnutls_initialized = false;

1497

2504

bool gpgme_initialized = false;

1543

2550

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

1544

2551

.arg = "FILE",

1545

2552

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

1546

.group = 2 },

2553

.group = 1 },

2554

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

2555

.arg = "FILE",

2556

#if GNUTLS_VERSION_NUMBER >= 0x030606

2557

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

2558

#else

2559

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

2560

#endif

2561

.group = 1 },

2562

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

2563

.arg = "FILE",

2564

#if GNUTLS_VERSION_NUMBER >= 0x030606

2565

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

2566

#else

2567

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

2568

#endif

2569

.group = 1 },

1547

2570

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

1548

2571

.arg = "BITS",

1549

2572

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

1550

2573

" Diffie-Hellman key exchange",

1551

2574

.group = 2 },

2575

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

2576

.arg = "FILE",

2577

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

2578

" for the Diffie-Hellman key exchange",

2579

.group = 2 },

1552

2580

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

1553

2581

.arg = "STRING",

1554

2582

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

1559

2587

.group = 2 },

1560

2588

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

1561

2589

.arg = "SECONDS",

1562

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

2590

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

1563

2591

.group = 2 },

1564

2592

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

1565

2593

.arg = "DIR",

1588

2616

connect_to = arg;

1589

2617

break;

1590

2618

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

1591

interface = arg;

2619

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

2620

arg, (int)',');

2621

if(ret_errno != 0){

2622

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

2623

}

1592

2624

break;

1593

2625

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

1594

2626

seckey = arg;

1596

2628

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

1597

2629

pubkey = arg;

1598

2630

break;

2631

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

2632

#if GNUTLS_VERSION_NUMBER >= 0x030606

2633

tls_privkey = arg;

2634

#endif

2635

break;

2636

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

2637

#if GNUTLS_VERSION_NUMBER >= 0x030606

2638

tls_pubkey = arg;

2639

#endif

2640

break;

1599

2641

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

1600

2642

errno = 0;

1601

2643

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

1605

2647

}

1606

2648

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

1607

2649

break;

2650

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

2651

dh_params_file = arg;

2652

break;

1608

2653

case 130: /* --priority */

1609

2654

mc.priority = arg;

1610

2655

break;

1633

2678

argp_state_help(state, state->out_stream,

1634

2679

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1635

2680

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2681

__builtin_unreachable();

1636

2682

case -3: /* --usage */

1637

2683

argp_state_help(state, state->out_stream,

1638

2684

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2685

__builtin_unreachable();

1639

2686

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

1640

fprintf_plus(state->out_stream,

1641

"Mandos plugin mandos-client: ");

1642

2687

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

1643

2688

exit(argp_err_exit_status);

1644

2689

break;

1652

2697

.args_doc = "",

1653

2698

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

1654

2699

" passwords from a Mandos server" };

1655

ret = argp_parse(&argp, argc, argv,

1656

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1657

switch(ret){

2700

ret_errno = argp_parse(&argp, argc, argv,

2701

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2702

switch(ret_errno){

1658

2703

case 0:

1659

2704

break;

1660

2705

case ENOMEM:

1661

2706

default:

1662

errno = ret;

2707

errno = ret_errno;

1663

2708

perror_plus("argp_parse");

1664

2709

exitcode = EX_OSERR;

1665

2710

goto end;

1668

2713

goto end;

1669

2714

}

1670

2715

}

1671

2716

1672

2717

{

1673

2718

/* 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");

2719

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

2720

2721

/* Re-raise privileges */

2722

ret = raise_privileges();

2723

if(ret != 0){

2724

errno = ret;

2725

perror_plus("Failed to raise privileges");

2726

} else {

2727

struct stat st;

2728

2729

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

2730

int seckey_fd = open(seckey, O_RDONLY);

2731

if(seckey_fd == -1){

2732

perror_plus("open");

2733

} else {

2734

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

2735

if(ret == -1){

2736

perror_plus("fstat");

2737

} else {

2738

if(S_ISREG(st.st_mode)

2739

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

2740

ret = fchown(seckey_fd, uid, gid);

2741

if(ret == -1){

2742

perror_plus("fchown");

2743

}

2744

}

2745

}

2746

close(seckey_fd);

2747

}

2748

}

2749

2750

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

2751

int pubkey_fd = open(pubkey, O_RDONLY);

2752

if(pubkey_fd == -1){

2753

perror_plus("open");

2754

} else {

2755

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

2756

if(ret == -1){

2757

perror_plus("fstat");

2758

} else {

2759

if(S_ISREG(st.st_mode)

2760

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

2761

ret = fchown(pubkey_fd, uid, gid);

2762

if(ret == -1){

2763

perror_plus("fchown");

2764

}

2765

}

2766

}

2767

close(pubkey_fd);

2768

}

2769

}

2770

2771

if(dh_params_file != NULL

2772

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

2773

int dhparams_fd = open(dh_params_file, O_RDONLY);

2774

if(dhparams_fd == -1){

2775

perror_plus("open");

2776

} else {

2777

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

2778

if(ret == -1){

2779

perror_plus("fstat");

2780

} else {

2781

if(S_ISREG(st.st_mode)

2782

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

2783

ret = fchown(dhparams_fd, uid, gid);

2784

if(ret == -1){

2785

perror_plus("fchown");

2786

}

2787

}

2788

}

2789

close(dhparams_fd);

2790

}

2791

}

2792

2793

/* Lower privileges */

2794

ret = lower_privileges();

2795

if(ret != 0){

2796

errno = ret;

2797

perror_plus("Failed to lower privileges");

2798

}

2799

}

2800

}

2801

2802

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

2803

{

2804

char *interface = NULL;

2805

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

2806

interface))){

2807

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

2808

and if_nametoindex(interface) == 0){

2809

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

2810

fprintf_plus(stderr, "Not using nonexisting interface"

2811

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

2812

}

2813

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

2814

interface = NULL;

2815

}

1731

2816

}

1732

2817

}

1733

2818

1734

2819

/* Run network hooks */

1735

2820

{

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

}

2821

if(mc.interfaces != NULL){

2822

interfaces_hooks = malloc(mc.interfaces_size);

2823

if(interfaces_hooks == NULL){

2824

perror_plus("malloc");

2825

goto end;

2826

}

2827

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

2828

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

2829

}

2830

run_network_hooks("start", interfaces_hooks != NULL ?

2831

interfaces_hooks : "", delay);

1751

2832

}

1752

2833

1753

2834

if(not debug){

1754

2835

avahi_set_log_function(empty_log);

1755

2836

}

1756

2837

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

2838

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

1790

2839

from the signal handler */

1791

2840

/* Initialize the pseudo-RNG for Avahi */

1792

2841

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

1793

mc.simple_poll = avahi_simple_poll_new();

1794

if(mc.simple_poll == NULL){

2842

simple_poll = avahi_simple_poll_new();

2843

if(simple_poll == NULL){

1795

2844

fprintf_plus(stderr,

1796

2845

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

1797

2846

exitcode = EX_UNAVAILABLE;

1861

2910

}

1862

2911

}

1863

2912

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");

2913

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

2914

if(mc.interfaces == NULL){

2915

struct dirent **direntries = NULL;

2916

/* Look for any good interfaces */

2917

ret = scandir(sys_class_net, &direntries, good_interface,

2918

alphasort);

2919

if(ret >= 1){

2920

/* Add all found interfaces to interfaces list */

2921

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

2922

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

2923

direntries[i]->d_name);

2924

if(ret_errno != 0){

2925

errno = ret_errno;

2926

perror_plus("argz_add");

2927

free(direntries[i]);

2928

continue;

2929

}

2930

if(debug){

2931

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

2932

direntries[i]->d_name);

2933

}

2934

free(direntries[i]);

2935

}

2936

free(direntries);

2937

} else {

2938

if(ret == 0){

2939

free(direntries);

2940

}

2941

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

2942

exitcode = EXIT_FAILURE;

2943

goto end;

2944

}

2945

}

2946

2947

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

2948

{

2949

char *interface = NULL;

2950

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

2951

interface))){

2952

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

2953

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

2954

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

2955

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

2956

interface);

2957

interface = NULL;

2958

while((interface = argz_next(mc.interfaces,

2959

mc.interfaces_size, interface))){

2960

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

2961

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

2962

interface);

2963

interface = NULL;

1949

2964

}

1950

2965

}

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

2966

break;

1969

2967

}

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

}

2968

bool interface_was_up = interface_is_up(interface);

2969

errno = bring_up_interface(interface, delay);

2970

if(not interface_was_up){

2971

if(errno != 0){

2972

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

2973

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

2974

} else {

2975

errno = argz_add(&interfaces_to_take_down,

2976

&interfaces_to_take_down_size,

2977

interface);

2978

if(errno != 0){

2979

perror_plus("argz_add");

2980

}

2981

}

2982

}

2983

}

2984

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

2985

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

2986

}

2987

}

2988

2989

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

2990

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

2991

if(debug){

2992

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

2993

mc.interfaces);

2994

}

2995

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

1999

2996

}

2000

2997

2001

2998

if(quit_now){

2002

2999

goto end;

2003

3000

}

2004

3001

2005

ret = init_gnutls_global(pubkey, seckey);

3002

#if GNUTLS_VERSION_NUMBER >= 0x030606

3003

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

3004

#elif GNUTLS_VERSION_NUMBER < 0x030600

3005

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

3006

#else

3007

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

3008

#endif

2006

3009

if(ret == -1){

2007

3010

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

2008

3011

exitcode = EX_UNAVAILABLE;

2015

3018

goto end;

2016

3019

}

2017

3020

2018

if(mkdtemp(tempdir) == NULL){

3021

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

3022

tempdir = mkdtemp(run_tempdir);

3023

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

3024

if(debug){

3025

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

3026

run_tempdir, old_tempdir);

3027

}

3028

tempdir = mkdtemp(old_tempdir);

3029

}

3030

if(tempdir == NULL){

2019

3031

perror_plus("mkdtemp");

2020

3032

goto end;

2021

3033

}

2022

tempdir_created = true;

2023

3034

2024

3035

if(quit_now){

2025

3036

goto end;

2026

3037

}

2027

3038

2028

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

3039

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

2029

3040

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

2030

3041

exitcode = EX_UNAVAILABLE;

2031

3042

goto end;

2041

3052

/* Connect directly, do not use Zeroconf */

2042

3053

/* (Mainly meant for debugging) */

2043

3054

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

3055

2044

3056

if(address == NULL){

2045

3057

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

2046

3058

exitcode = EX_USAGE;

2051

3063

goto end;

2052

3064

}

2053

3065

2054

uint16_t port;

3066

in_port_t port;

2055

3067

errno = 0;

2056

3068

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

2057

3069

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

2058

or tmpmax != (uint16_t)tmpmax){

3070

or tmpmax != (in_port_t)tmpmax){

2059

3071

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

2060

3072

exitcode = EX_USAGE;

2061

3073

goto end;

2062

3074

}

2063

3075

2064

3076

if(quit_now){

2065

3077

goto end;

2066

3078

}

2067

3079

2068

port = (uint16_t)tmpmax;

3080

port = (in_port_t)tmpmax;

2069

3081

*address = '\0';

2070

3082

/* Colon in address indicates IPv6 */

2071

3083

int af;

2087

3099

}

2088

3100

2089

3101

while(not quit_now){

2090

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

3102

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

3103

&mc);

2091

3104

if(quit_now or ret == 0){

2092

3105

break;

2093

3106

}

2095

3108

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

2096

3109

(int)retry_interval);

2097

3110

}

2098

sleep((int)retry_interval);

3111

sleep((unsigned int)retry_interval);

2099

3112

}

2100

3113

2101

if (not quit_now){

3114

if(not quit_now){

2102

3115

exitcode = EXIT_SUCCESS;

2103

3116

}

2104

3117

2119

3132

config.publish_domain = 0;

2120

3133

2121

3134

/* Allocate a new server */

2122

mc.server = avahi_server_new(avahi_simple_poll_get

2123

(mc.simple_poll), &config, NULL,

2124

NULL, &error);

3135

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3136

&config, NULL, NULL, &ret);

2125

3137

2126

3138

/* Free the Avahi configuration data */

2127

3139

avahi_server_config_free(&config);

2130

3142

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

2131

3143

if(mc.server == NULL){

2132

3144

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

2133

avahi_strerror(error));

3145

avahi_strerror(ret));

2134

3146

exitcode = EX_UNAVAILABLE;

2135

3147

goto end;

2136

3148

}

2142

3154

/* Create the Avahi service browser */

2143

3155

sb = avahi_s_service_browser_new(mc.server, if_index,

2144

3156

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2145

NULL, 0, browse_callback, NULL);

3157

NULL, 0, browse_callback,

3158

(void *)&mc);

2146

3159

if(sb == NULL){

2147

3160

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

2148

3161

avahi_strerror(avahi_server_errno(mc.server)));

2159

3172

if(debug){

2160

3173

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

2161

3174

}

2162

2163

ret = avahi_loop_with_timeout(mc.simple_poll,

2164

(int)(retry_interval * 1000));

3175

3176

ret = avahi_loop_with_timeout(simple_poll,

3177

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

2165

3178

if(debug){

2166

3179

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

2167

3180

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

2170

3183

end:

2171

3184

2172

3185

if(debug){

2173

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

3186

if(signal_received){

3187

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

3188

argv[0], signal_received,

3189

strsignal(signal_received));

3190

} else {

3191

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

3192

}

2174

3193

}

2175

3194

2176

3195

/* Cleanup things */

3196

free(mc.interfaces);

3197

2177

3198

if(sb != NULL)

2178

3199

avahi_s_service_browser_free(sb);

2179

3200

2180

3201

if(mc.server != NULL)

2181

3202

avahi_server_free(mc.server);

2182

3203

2183

if(mc.simple_poll != NULL)

2184

avahi_simple_poll_free(mc.simple_poll);

3204

if(simple_poll != NULL)

3205

avahi_simple_poll_free(simple_poll);

2185

3206

2186

3207

if(gnutls_initialized){

2187

3208

gnutls_certificate_free_credentials(mc.cred);

2188

gnutls_global_deinit();

2189

3209

gnutls_dh_params_deinit(mc.dh_params);

2190

3210

}

2191

3211

2192

3212

if(gpgme_initialized){

2193

3213

gpgme_release(mc.ctx);

2194

3214

}

2195

3215

2196

3216

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

2197

3217

has seen */

2198

3218

if(mc.current_server != NULL){

2199

3219

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

2200

3220

while(mc.current_server != NULL){

2201

3221

server *next = mc.current_server->next;

3222

#ifdef __GNUC__

3223

#pragma GCC diagnostic push

3224

#pragma GCC diagnostic ignored "-Wcast-qual"

3225

#endif

3226

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

3227

#ifdef __GNUC__

3228

#pragma GCC diagnostic pop

3229

#endif

2202

3230

free(mc.current_server);

2203

3231

mc.current_server = next;

2204

3232

}

2205

3233

}

2206

3234

2207

/* Re-raise priviliges */

3235

/* Re-raise privileges */

2208

3236

{

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;

3237

ret = raise_privileges();

3238

if(ret != 0){

3239

errno = ret;

3240

perror_plus("Failed to raise privileges");

3241

} else {

3242

3243

/* Run network hooks */

3244

run_network_hooks("stop", interfaces_hooks != NULL ?

3245

interfaces_hooks : "", delay);

3246

3247

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

3248

{

3249

char *interface = NULL;

3250

while((interface = argz_next(interfaces_to_take_down,

3251

interfaces_to_take_down_size,

3252

interface))){

3253

ret = take_down_interface(interface);

3254

if(ret != 0){

3255

errno = ret;

3256

perror_plus("Failed to take down interface");

3257

}

3258

}

3259

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

3260

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

3261

" down\n");

3262

}

3263

}

2217

3264

}

2218

3265

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

}

3266

ret = lower_privileges_permanently();

3267

if(ret != 0){

3268

errno = ret;

3269

perror_plus("Failed to lower privileges permanently");

2235

3270

}

2236

3271

}

2237

/* Lower privileges permanently */

2238

errno = 0;

2239

ret = setuid(uid);

2240

if(ret == -1){

2241

perror_plus("setuid");

3272

3273

free(interfaces_to_take_down);

3274

free(interfaces_hooks);

3275

3276

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

3277

uintmax_t level){

3278

struct dirent **direntries = NULL;

3279

int dret;

3280

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

3281

O_RDONLY

3282

| O_NOFOLLOW

3283

| O_DIRECTORY

3284

| O_PATH));

3285

if(dir_fd == -1){

3286

perror_plus("open");

3287

return;

3288

}

3289

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

3290

notdotentries, alphasort);

3291

if(numentries >= 0){

3292

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

3293

if(debug){

3294

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

3295

dirname, direntries[i]->d_name);

3296

}

3297

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

3298

if(dret == -1){

3299

if(errno == EISDIR){

3300

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

3301

AT_REMOVEDIR);

3302

}

3303

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

3304

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

3305

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

3306

/* Recurse only in this special case */

3307

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

3308

dret = 0;

3309

}

3310

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

3311

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

3312

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

3313

}

3314

}

3315

free(direntries[i]);

3316

}

3317

3318

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

3319

free(direntries);

3320

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3321

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

3322

perror_plus("rmdir");

3323

}

3324

} else {

3325

perror_plus("scandirat");

3326

}

3327

close(dir_fd);

2242

3328

}

2243

3329

2244

3330

/* 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

}

3331

if(tempdir != NULL){

3332

clean_dir_at(-1, tempdir, 0);

2278

3333

}

2279

3334

2280

3335

if(quit_now){