/mandos/release : revision 237.7.316

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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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* along with this program. If not, see

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

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*

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* Contact the authors at <mandos@fukt.bsnet.se>.

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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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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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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() */

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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 <time.h> /* nanosleep(), time() */

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

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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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SIOCSIFFLAGS, if_indextoname(),

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if_nametoindex(), IF_NAMESIZE */

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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 */

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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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raise() */

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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

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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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118

init_gnutls_session(),

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119

GNUTLS_* */

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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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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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125

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

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133

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

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134

#define SECKEY "seckey.txt"

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135

#define PUBKEY "pubkey.txt"

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

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137

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bool debug = false;

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139

static const char mandos_protocol_version[] = "1";

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const char *argp_program_version = "mandos-client " VERSION;

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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

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const char *argp_program_bug_address = "<mandos@recompile.se>";

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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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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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struct server *next;

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struct server *prev;

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} server;

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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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164

unsigned int dh_bits;

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gnutls_dh_params_t dh_params;

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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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171

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

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AvahiSimplePoll *simple_poll;

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175

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sig_atomic_t quit_now = 0;

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177

int signal_received = 0;

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179

/* Function to use when printing errors */

180

void perror_plus(const char *print_text){

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int e = errno;

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

183

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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188

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

189

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

190

va_list ap;

191

va_start (ap, format);

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193

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

194

program_invocation_short_name));

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

196

}

197

150

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/*

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199

* Make additional room in "buffer" for at least BUFFER_SIZE more

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200

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

153

201

* "buffer_length" is how much is already used.

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202

*/

203

__attribute__((nonnull, warn_unused_result))

155

204

size_t incbuffer(char **buffer, size_t buffer_length,

156

size_t buffer_capacity){

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size_t buffer_capacity){

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206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

158

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

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if(buffer == NULL){

207

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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214

}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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217

}

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return buffer_capacity;

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219

}

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

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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;

226

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

227

if(new_server == NULL){

228

perror_plus("malloc");

229

return false;

230

}

231

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

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.port = port,

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.if_index = if_index,

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.af = af };

235

if(new_server->ip == NULL){

236

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

return false;

253

}

254

/* Special case of first server */

255

if(*current_server == NULL){

256

new_server->next = new_server;

257

new_server->prev = new_server;

258

*current_server = new_server;

259

} else {

260

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

261

new_server->next = *current_server;

262

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

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

266

return true;

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}

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/*

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* Initialize GPGME.

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271

*/

170

static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

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__attribute__((nonnull, warn_unused_result))

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static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

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const char * const tempdir,

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mandos_context *mc){

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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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/*

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281

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

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282

*/

179

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

180

284

int ret;

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285

int fd;

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gpgme_data_t pgp_data;

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288

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

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if(fd == -1){

186

perror("open");

290

perror_plus("open");

187

291

return false;

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292

}

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293

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

191

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

296

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

195

299

}

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300

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rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

198

302

if(rc != GPG_ERR_NO_ERROR){

199

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

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gpgme_strsource(rc), gpgme_strerror(rc));

303

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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305

return false;

202

306

}

203

307

204

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

205

309

if(ret == -1){

206

perror("close");

310

perror_plus("close");

207

311

}

208

312

gpgme_data_release(pgp_data);

209

313

return true;

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314

}

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315

212

316

if(debug){

213

fprintf(stderr, "Initializing GPGME\n");

317

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

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318

}

215

319

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320

/* Init GPGME */

217

321

gpgme_check_version(NULL);

218

322

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

219

323

if(rc != GPG_ERR_NO_ERROR){

220

fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",

221

gpgme_strsource(rc), gpgme_strerror(rc));

324

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

325

gpgme_strsource(rc), gpgme_strerror(rc));

222

326

return false;

223

327

}

224

328

225

/* Set GPGME home directory for the OpenPGP engine only */

329

/* Set GPGME home directory for the OpenPGP engine only */

226

330

rc = gpgme_get_engine_info(&engine_info);

227

331

if(rc != GPG_ERR_NO_ERROR){

228

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

229

gpgme_strsource(rc), gpgme_strerror(rc));

332

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

333

gpgme_strsource(rc), gpgme_strerror(rc));

230

334

return false;

231

335

}

232

336

while(engine_info != NULL){

238

342

engine_info = engine_info->next;

239

343

}

240

344

if(engine_info == NULL){

241

fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

345

fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",

346

tempdir);

242

347

return false;

243

348

}

244

349

245

350

/* Create new GPGME "context" */

246

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

351

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

247

352

if(rc != GPG_ERR_NO_ERROR){

248

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

249

gpgme_strsource(rc), gpgme_strerror(rc));

353

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

354

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

355

gpgme_strerror(rc));

250

356

return false;

251

357

}

252

358

261

367

* Decrypt OpenPGP data.

262

368

* Returns -1 on error

263

369

*/

370

__attribute__((nonnull, warn_unused_result))

264

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

265

372

size_t crypto_size,

266

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

267

375

gpgme_data_t dh_crypto, dh_plain;

268

376

gpgme_error_t rc;

269

377

ssize_t ret;

271

379

ssize_t plaintext_length = 0;

272

380

273

381

if(debug){

274

fprintf(stderr, "Trying to decrypt OpenPGP data\n");

382

fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");

275

383

}

276

384

277

385

/* Create new GPGME data buffer from memory cryptotext */

278

386

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

279

387

0);

280

388

if(rc != GPG_ERR_NO_ERROR){

281

fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

282

gpgme_strsource(rc), gpgme_strerror(rc));

389

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

390

gpgme_strsource(rc), gpgme_strerror(rc));

283

391

return -1;

284

392

}

285

393

286

394

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

287

395

rc = gpgme_data_new(&dh_plain);

288

396

if(rc != GPG_ERR_NO_ERROR){

289

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

290

gpgme_strsource(rc), gpgme_strerror(rc));

397

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

398

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

399

gpgme_strsource(rc), gpgme_strerror(rc));

291

400

gpgme_data_release(dh_crypto);

292

401

return -1;

293

402

}

294

403

295

404

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

296

405

data buffer */

297

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

406

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

298

407

if(rc != GPG_ERR_NO_ERROR){

299

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

300

gpgme_strsource(rc), gpgme_strerror(rc));

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

301

410

plaintext_length = -1;

302

411

if(debug){

303

412

gpgme_decrypt_result_t result;

304

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

305

414

if(result == NULL){

306

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

415

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

307

416

} else {

308

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

309

result->unsupported_algorithm);

310

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

311

result->wrong_key_usage);

417

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

418

result->unsupported_algorithm);

419

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

420

result->wrong_key_usage);

312

421

if(result->file_name != NULL){

313

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

422

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

314

423

}

315

424

gpgme_recipient_t recipient;

316

425

recipient = result->recipients;

317

426

while(recipient != NULL){

318

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

319

gpgme_pubkey_algo_name(recipient->pubkey_algo));

320

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

321

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

322

recipient->status == GPG_ERR_NO_SECKEY

323

? "No" : "Yes");

427

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

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

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

431

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

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "No" : "Yes");

324

434

recipient = recipient->next;

325

435

}

326

436

}

329

439

}

330

440

331

441

if(debug){

332

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

442

fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");

333

443

}

334

444

335

445

/* Seek back to the beginning of the GPGME plaintext data buffer */

336

446

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

337

perror("gpgme_data_seek");

447

perror_plus("gpgme_data_seek");

338

448

plaintext_length = -1;

339

449

goto decrypt_end;

340

450

}

342

452

*plaintext = NULL;

343

453

while(true){

344

454

plaintext_capacity = incbuffer(plaintext,

345

(size_t)plaintext_length,

346

plaintext_capacity);

455

(size_t)plaintext_length,

456

plaintext_capacity);

347

457

if(plaintext_capacity == 0){

348

perror("incbuffer");

349

plaintext_length = -1;

350

goto decrypt_end;

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

351

461

}

352

462

353

463

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

358

468

break;

359

469

}

360

470

if(ret < 0){

361

perror("gpgme_data_read");

471

perror_plus("gpgme_data_read");

362

472

plaintext_length = -1;

363

473

goto decrypt_end;

364

474

}

366

476

}

367

477

368

478

if(debug){

369

fprintf(stderr, "Decrypted password is: ");

479

fprintf_plus(stderr, "Decrypted password is: ");

370

480

for(ssize_t i = 0; i < plaintext_length; i++){

371

481

fprintf(stderr, "%02hhX ", (*plaintext)[i]);

372

482

}

383

493

return plaintext_length;

384

494

}

385

495

386

static const char * safer_gnutls_strerror(int value){

387

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

388

-Wunreachable-code */

389

if(ret == NULL)

390

ret = "(unknown)";

391

return ret;

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

505

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

392

507

}

393

508

394

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

395

511

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

396

512

const char* string){

397

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

513

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

398

514

}

399

515

516

__attribute__((nonnull, warn_unused_result))

400

517

static int init_gnutls_global(const char *pubkeyfilename,

401

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

402

521

int ret;

522

unsigned int uret;

403

523

404

524

if(debug){

405

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

525

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

406

526

}

407

527

408

528

ret = gnutls_global_init();

409

529

if(ret != GNUTLS_E_SUCCESS){

410

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

411

safer_gnutls_strerror(ret));

530

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

531

safer_gnutls_strerror(ret));

412

532

return -1;

413

533

}

414

534

421

541

}

422

542

423

543

/* OpenPGP credentials */

424

gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

425

545

if(ret != GNUTLS_E_SUCCESS){

426

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

427

from

428

-Wunreachable-code

429

*/

430

safer_gnutls_strerror(ret));

546

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

547

safer_gnutls_strerror(ret));

431

548

gnutls_global_deinit();

432

549

return -1;

433

550

}

434

551

435

552

if(debug){

436

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

437

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

438

seckeyfilename);

553

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

554

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

555

pubkeyfilename,

556

seckeyfilename);

439

557

}

440

558

441

559

ret = gnutls_certificate_set_openpgp_key_file

442

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

443

561

GNUTLS_OPENPGP_FMT_BASE64);

444

562

if(ret != GNUTLS_E_SUCCESS){

445

fprintf(stderr,

446

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

447

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

448

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

449

safer_gnutls_strerror(ret));

563

fprintf_plus(stderr,

564

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

565

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

566

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

567

safer_gnutls_strerror(ret));

450

568

goto globalfail;

451

569

}

452

570

453

571

/* GnuTLS server initialization */

454

ret = gnutls_dh_params_init(&mc.dh_params);

455

if(ret != GNUTLS_E_SUCCESS){

456

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

457

" %s\n", safer_gnutls_strerror(ret));

458

goto globalfail;

459

}

460

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

461

if(ret != GNUTLS_E_SUCCESS){

462

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

463

safer_gnutls_strerror(ret));

464

goto globalfail;

465

}

466

467

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

573

if(ret != GNUTLS_E_SUCCESS){

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

" initialization: %s\n",

576

safer_gnutls_strerror(ret));

577

goto globalfail;

578

}

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

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

468

752

469

753

return 0;

470

754

471

755

globalfail:

472

756

473

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

474

758

gnutls_global_deinit();

475

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

476

760

return -1;

477

761

}

478

762

479

static int init_gnutls_session(gnutls_session_t *session){

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

480

766

int ret;

481

767

/* GnuTLS session creation */

482

768

do {

486

772

}

487

773

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

488

774

if(ret != GNUTLS_E_SUCCESS){

489

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

490

safer_gnutls_strerror(ret));

775

fprintf_plus(stderr,

776

"Error in GnuTLS session initialization: %s\n",

777

safer_gnutls_strerror(ret));

491

778

}

492

779

493

780

{

494

781

const char *err;

495

782

do {

496

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

783

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

497

784

if(quit_now){

498

785

gnutls_deinit(*session);

499

786

return -1;

500

787

}

501

788

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

502

789

if(ret != GNUTLS_E_SUCCESS){

503

fprintf(stderr, "Syntax error at: %s\n", err);

504

fprintf(stderr, "GnuTLS error: %s\n",

505

safer_gnutls_strerror(ret));

790

fprintf_plus(stderr, "Syntax error at: %s\n", err);

791

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

792

safer_gnutls_strerror(ret));

506

793

gnutls_deinit(*session);

507

794

return -1;

508

795

}

510

797

511

798

do {

512

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

513

mc.cred);

800

mc->cred);

514

801

if(quit_now){

515

802

gnutls_deinit(*session);

516

803

return -1;

517

804

}

518

805

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

519

806

if(ret != GNUTLS_E_SUCCESS){

520

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

521

safer_gnutls_strerror(ret));

807

fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",

808

safer_gnutls_strerror(ret));

522

809

gnutls_deinit(*session);

523

810

return -1;

524

811

}

526

813

/* ignore client certificate if any. */

527

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

528

815

529

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

530

531

816

return 0;

532

817

}

533

818

535

820

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

536

821

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

537

822

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

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

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

_exit(EX_UNAVAILABLE);

958

}

959

TEMP_FAILURE_RETRY(close(helperdir_fd));

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

538

1040

/* Called when a Mandos server is found */

539

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

1041

__attribute__((nonnull, warn_unused_result))

1042

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

540

1043

AvahiIfIndex if_index,

541

int af){

1044

int af, mandos_context *mc){

542

1045

int ret, tcp_sd = -1;

543

1046

ssize_t sret;

544

union {

545

struct sockaddr_in in;

546

struct sockaddr_in6 in6;

547

} to;

1047

struct sockaddr_storage to;

548

1048

char *buffer = NULL;

549

1049

char *decrypted_buffer = NULL;

550

1050

size_t buffer_length = 0;

553

1053

int retval = -1;

554

1054

gnutls_session_t session;

555

1055

int pf; /* Protocol family */

1056

bool route_added = false;

556

1057

557

1058

errno = 0;

558

1059

569

1070

pf = PF_INET;

570

1071

break;

571

1072

default:

572

fprintf(stderr, "Bad address family: %d\n", af);

1073

fprintf_plus(stderr, "Bad address family: %d\n", af);

573

1074

errno = EINVAL;

574

1075

return -1;

575

1076

}

576

1077

577

ret = init_gnutls_session(&session);

1078

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

1079

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

1080

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

1081

bool match = false;

1082

{

1083

char *interface = NULL;

1084

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

1085

interface))){

1086

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

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

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

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

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

1098

perror_plus("if_indextoname");

1099

} else {

1100

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

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

578

1111

if(ret != 0){

579

1112

return -1;

580

1113

}

581

1114

582

1115

if(debug){

583

fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16

584

"\n", ip, port);

1116

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

1117

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

585

1118

}

586

1119

587

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

588

1121

if(tcp_sd < 0){

589

1122

int e = errno;

590

perror("socket");

1123

perror_plus("socket");

591

1124

errno = e;

592

1125

goto mandos_end;

593

1126

}

599

1132

600

1133

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

601

1134

if(af == AF_INET6){

602

to.in6.sin6_family = (sa_family_t)af;

603

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

1135

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

1136

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

604

1137

} else { /* IPv4 */

605

to.in.sin_family = (sa_family_t)af;

606

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

1138

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

1139

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

607

1140

}

608

1141

if(ret < 0 ){

609

1142

int e = errno;

610

perror("inet_pton");

1143

perror_plus("inet_pton");

611

1144

errno = e;

612

1145

goto mandos_end;

613

1146

}

614

1147

if(ret == 0){

615

1148

int e = errno;

616

fprintf(stderr, "Bad address: %s\n", ip);

1149

fprintf_plus(stderr, "Bad address: %s\n", ip);

617

1150

errno = e;

618

1151

goto mandos_end;

619

1152

}

620

1153

if(af == AF_INET6){

621

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

622

-Wconversion and

623

-Wunreachable-code */

624

625

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

626

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

627

-Wunreachable-code*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

628

1157

if(if_index == AVAHI_IF_UNSPEC){

629

fprintf(stderr, "An IPv6 link-local address is incomplete"

630

" without a network interface\n");

1158

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

1159

" incomplete without a network interface\n");

631

1160

errno = EINVAL;

632

1161

goto mandos_end;

633

1162

}

634

1163

/* Set the network interface number as scope */

635

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

636

1165

}

637

1166

} else {

638

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

639

-Wconversion and

640

-Wunreachable-code */

1167

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

641

1168

}

642

1169

643

1170

if(quit_now){

649

1176

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

650

1177

char interface[IF_NAMESIZE];

651

1178

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

652

perror("if_indextoname");

1179

perror_plus("if_indextoname");

653

1180

} else {

654

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

655

ip, interface, port);

1181

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

1182

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

656

1183

}

657

1184

} else {

658

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

659

port);

1185

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

1186

ip, (uintmax_t)port);

660

1187

}

661

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

662

1189

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

663

const char *pcret;

664

if(af == AF_INET6){

665

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

666

sizeof(addrstr));

667

} else {

668

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

669

sizeof(addrstr));

670

}

671

if(pcret == NULL){

672

perror("inet_ntop");

673

} else {

674

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

675

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

676

}

677

}

678

}

679

680

if(quit_now){

681

errno = EINTR;

682

goto mandos_end;

683

}

684

685

if(af == AF_INET6){

686

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

687

} else {

688

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

689

}

690

if(ret < 0){

691

int e = errno;

692

perror("connect");

693

errno = e;

694

goto mandos_end;

695

}

696

697

if(quit_now){

698

errno = EINTR;

699

goto mandos_end;

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

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

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(errno == ENETUNREACH

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

700

1270

}

701

1271

702

1272

const char *out = mandos_protocol_version;

704

1274

while(true){

705

1275

size_t out_size = strlen(out);

706

1276

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

707

out_size - written));

1277

out_size - written));

708

1278

if(ret == -1){

709

1279

int e = errno;

710

perror("write");

1280

perror_plus("write");

711

1281

errno = e;

712

1282

goto mandos_end;

713

1283

}

730

1300

}

731

1301

732

1302

if(debug){

733

fprintf(stderr, "Establishing TLS session with %s\n", ip);

1303

fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);

734

1304

}

735

1305

736

1306

if(quit_now){

738

1308

goto mandos_end;

739

1309

}

740

1310

741

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1311

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

1312

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

1313

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

1314

gnutls_transport_set_ptr(session,

1315

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

742

1316

743

1317

if(quit_now){

744

1318

errno = EINTR;

755

1329

756

1330

if(ret != GNUTLS_E_SUCCESS){

757

1331

if(debug){

758

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

1332

fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");

759

1333

gnutls_perror(ret);

760

1334

}

761

1335

errno = EPROTO;

765

1339

/* Read OpenPGP packet that contains the wanted password */

766

1340

767

1341

if(debug){

768

fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",

769

ip);

1342

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1343

" %s\n", ip);

770

1344

}

771

1345

772

1346

while(true){

777

1351

}

778

1352

779

1353

buffer_capacity = incbuffer(&buffer, buffer_length,

780

buffer_capacity);

1354

buffer_capacity);

781

1355

if(buffer_capacity == 0){

782

1356

int e = errno;

783

perror("incbuffer");

1357

perror_plus("incbuffer");

784

1358

errno = e;

785

1359

goto mandos_end;

786

1360

}

810

1384

}

811

1385

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

812

1386

if(ret < 0){

813

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

1387

fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "

1388

"***\n");

814

1389

gnutls_perror(ret);

815

1390

errno = EPROTO;

816

1391

goto mandos_end;

817

1392

}

818

1393

break;

819

1394

default:

820

fprintf(stderr, "Unknown error while reading data from"

821

" encrypted session with Mandos server\n");

1395

fprintf_plus(stderr, "Unknown error while reading data from"

1396

" encrypted session with Mandos server\n");

822

1397

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

1398

errno = EIO;

824

1399

goto mandos_end;

829

1404

}

830

1405

831

1406

if(debug){

832

fprintf(stderr, "Closing TLS session\n");

1407

fprintf_plus(stderr, "Closing TLS session\n");

833

1408

}

834

1409

835

1410

if(quit_now){

847

1422

848

1423

if(buffer_length > 0){

849

1424

ssize_t decrypted_buffer_size;

850

decrypted_buffer_size = pgp_packet_decrypt(buffer,

851

buffer_length,

852

&decrypted_buffer);

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

853

1427

if(decrypted_buffer_size >= 0){

854

1428

855

1429

written = 0;

865

1439

if(ret == 0 and ferror(stdout)){

866

1440

int e = errno;

867

1441

if(debug){

868

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

869

strerror(errno));

1442

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

1443

strerror(errno));

870

1444

}

871

1445

errno = e;

872

1446

goto mandos_end;

881

1455

882

1456

mandos_end:

883

1457

{

1458

if(route_added){

1459

if(not delete_local_route(ip, if_index)){

1460

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

1461

" interface %d", ip, if_index);

1462

}

1463

}

884

1464

int e = errno;

885

1465

free(decrypted_buffer);

886

1466

free(buffer);

891

1471

if(e == 0){

892

1472

e = errno;

893

1473

}

894

perror("close");

1474

perror_plus("close");

895

1475

}

896

1476

gnutls_deinit(session);

1477

errno = e;

897

1478

if(quit_now){

898

e = EINTR;

1479

errno = EINTR;

899

1480

retval = -1;

900

1481

}

901

errno = e;

902

1482

}

903

1483

return retval;

904

1484

}

905

1485

1486

__attribute__((nonnull))

906

1487

static void resolve_callback(AvahiSServiceResolver *r,

907

1488

AvahiIfIndex interface,

908

1489

AvahiProtocol proto,

916

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

917

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

918

1499

flags,

919

AVAHI_GCC_UNUSED void* userdata){

920

assert(r);

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

921

1504

922

1505

/* Called whenever a service has been resolved successfully or

923

1506

timed out */

924

1507

925

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

926

1510

return;

927

1511

}

928

1512

929

1513

switch(event){

930

1514

default:

931

1515

case AVAHI_RESOLVER_FAILURE:

932

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

933

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

934

avahi_strerror(avahi_server_errno(mc.server)));

1516

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

1517

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

1518

domain,

1519

avahi_strerror(avahi_server_errno

1520

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

935

1521

break;

936

1522

937

1523

case AVAHI_RESOLVER_FOUND:

939

1525

char ip[AVAHI_ADDRESS_STR_MAX];

940

1526

avahi_address_snprint(ip, sizeof(ip), address);

941

1527

if(debug){

942

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"

943

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

944

ip, (intmax_t)interface, port);

1528

fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"

1529

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

1530

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

945

1531

}

946

int ret = start_mandos_communication(ip, port, interface,

947

avahi_proto_to_af(proto));

1532

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

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

948

1536

if(ret == 0){

949

avahi_simple_poll_quit(mc.simple_poll);

1537

avahi_simple_poll_quit(simple_poll);

1538

} else {

1539

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

1540

avahi_proto_to_af(proto),

1541

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

1542

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

1543

" list\n", name);

1544

}

950

1545

}

951

1546

}

952

1547

}

962

1557

const char *domain,

963

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

964

1559

flags,

965

AVAHI_GCC_UNUSED void* userdata){

966

assert(b);

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

967

1564

968

1565

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

969

1566

is removed from the LAN */

976

1573

default:

977

1574

case AVAHI_BROWSER_FAILURE:

978

1575

979

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

980

avahi_strerror(avahi_server_errno(mc.server)));

981

avahi_simple_poll_quit(mc.simple_poll);

1576

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

1577

avahi_strerror(avahi_server_errno

1578

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

1579

avahi_simple_poll_quit(simple_poll);

982

1580

return;

983

1581

984

1582

case AVAHI_BROWSER_NEW:

987

1585

the callback function is called the Avahi server will free the

988

1586

resolver for us. */

989

1587

990

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

991

name, type, domain, protocol, 0,

992

resolve_callback, NULL) == NULL)

993

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

994

name, avahi_strerror(avahi_server_errno(mc.server)));

1588

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

1589

interface, protocol, name, type,

1590

domain, protocol, 0,

1591

resolve_callback, mc) == NULL)

1592

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

1593

" %s\n", name,

1594

avahi_strerror(avahi_server_errno

1595

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

995

1596

break;

996

1597

997

1598

case AVAHI_BROWSER_REMOVE:

1000

1601

case AVAHI_BROWSER_ALL_FOR_NOW:

1001

1602

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1002

1603

if(debug){

1003

fprintf(stderr, "No Mandos server found, still searching...\n");

1604

fprintf_plus(stderr, "No Mandos server found, still"

1605

" searching...\n");

1004

1606

}

1005

1607

break;

1006

1608

}

1007

1609

}

1008

1610

1009

/* stop main loop after sigterm has been called */

1611

/* Signal handler that stops main loop after SIGTERM */

1010

1612

static void handle_sigterm(int sig){

1011

1613

if(quit_now){

1012

1614

return;

1014

1616

quit_now = 1;

1015

1617

signal_received = sig;

1016

1618

int old_errno = errno;

1017

if(mc.simple_poll != NULL){

1018

avahi_simple_poll_quit(mc.simple_poll);

1019

}

1020

errno = old_errno;

1619

/* set main loop to exit */

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1622

}

1623

errno = old_errno;

1624

}

1625

1626

__attribute__((nonnull, warn_unused_result))

1627

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

1628

int ret;

1629

error_t ret_errno;

1630

1631

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

1632

if(s < 0){

1633

ret_errno = errno;

1634

perror_plus("socket");

1635

errno = ret_errno;

1636

return false;

1637

}

1638

strcpy(ifr->ifr_name, ifname);

1639

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1640

if(ret == -1){

1641

if(debug){

1642

ret_errno = errno;

1643

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1645

}

1646

return false;

1647

}

1648

return true;

1649

}

1650

1651

__attribute__((nonnull, warn_unused_result))

1652

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

1653

1654

/* Reject the loopback device */

1655

if(ifr->ifr_flags & IFF_LOOPBACK){

1656

if(debug){

1657

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

1658

ifname);

1659

}

1660

return false;

1661

}

1662

/* Accept point-to-point devices only if connect_to is specified */

1663

if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){

1664

if(debug){

1665

fprintf_plus(stderr, "Accepting point-to-point interface"

1666

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

1667

}

1668

return true;

1669

}

1670

/* Otherwise, reject non-broadcast-capable devices */

1671

if(not (ifr->ifr_flags & IFF_BROADCAST)){

1672

if(debug){

1673

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1674

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

1675

}

1676

return false;

1677

}

1678

/* Reject non-ARP interfaces (including dummy interfaces) */

1679

if(ifr->ifr_flags & IFF_NOARP){

1680

if(debug){

1681

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

1682

ifname);

1683

}

1684

return false;

1685

}

1686

1687

/* Accept this device */

1688

if(debug){

1689

fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);

1690

}

1691

return true;

1692

}

1693

1694

/*

1695

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

1696

* corresponds to an acceptable network device.

1697

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

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

int good_interface(const struct dirent *if_entry){

1701

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

1702

return 0;

1703

}

1704

1705

struct ifreq ifr;

1706

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

1707

if(debug){

1708

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

1709

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

1710

}

1711

return 0;

1712

}

1713

1714

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

1715

return 0;

1716

}

1717

return 1;

1718

}

1719

1720

/*

1721

* This function determines if a network interface is up.

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1724

bool interface_is_up(const char *interface){

1725

struct ifreq ifr;

1726

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

1727

if(debug){

1728

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

1729

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

1730

}

1731

return false;

1732

}

1733

1734

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

1735

}

1736

1737

/*

1738

* This function determines if a network interface is running

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1741

bool interface_is_running(const char *interface){

1742

struct ifreq ifr;

1743

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

1744

if(debug){

1745

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

1746

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

1747

}

1748

return false;

1749

}

1750

1751

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

1752

}

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1755

int notdotentries(const struct dirent *direntry){

1756

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

1757

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

1758

and (direntry->d_name[1] == '\0'

1759

or (direntry->d_name[1] == '.'

1760

and direntry->d_name[2] == '\0'))){

1761

return 0;

1762

}

1763

return 1;

1764

}

1765

1766

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

1767

__attribute__((nonnull, warn_unused_result))

1768

int runnable_hook(const struct dirent *direntry){

1769

int ret;

1770

size_t sret;

1771

struct stat st;

1772

1773

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

1774

/* Empty name? */

1775

return 0;

1776

}

1777

1778

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

1779

"abcdefghijklmnopqrstuvwxyz"

1780

"0123456789"

1781

"_.-");

1782

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

1783

/* Contains non-allowed characters */

1784

if(debug){

1785

fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",

1786

direntry->d_name);

1787

}

1788

return 0;

1789

}

1790

1791

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

1792

if(ret == -1){

1793

if(debug){

1794

perror_plus("Could not stat hook");

1795

}

1796

return 0;

1797

}

1798

if(not (S_ISREG(st.st_mode))){

1799

/* Not a regular file */

1800

if(debug){

1801

fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",

1802

direntry->d_name);

1803

}

1804

return 0;

1805

}

1806

if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){

1807

/* Not executable */

1808

if(debug){

1809

fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",

1810

direntry->d_name);

1811

}

1812

return 0;

1813

}

1814

if(debug){

1815

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

1816

direntry->d_name);

1817

}

1818

return 1;

1819

}

1820

1821

__attribute__((nonnull, warn_unused_result))

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

mandos_context *mc){

1824

int ret;

1825

struct timespec now;

1826

struct timespec waited_time;

1827

intmax_t block_time;

1828

1829

while(true){

1830

if(mc->current_server == NULL){

1831

if(debug){

1832

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

1833

" No timeout!\n");

1834

}

1835

ret = avahi_simple_poll_iterate(s, -1);

1836

} else {

1837

if(debug){

1838

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

1839

" it, or wait\n");

1840

}

1841

/* the current time */

1842

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1843

if(ret == -1){

1844

perror_plus("clock_gettime");

1845

return -1;

1846

}

1847

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

1848

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

1849

waited_time.tv_sec = (now.tv_sec

1850

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

1851

waited_time.tv_nsec = (now.tv_nsec

1852

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

1853

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

1854

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

1855

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

1856

block_time = ((retry_interval

1857

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

1858

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

1859

1860

if(debug){

1861

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

1862

block_time);

1863

}

1864

1865

if(block_time <= 0){

1866

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

1867

mc->current_server->port,

1868

mc->current_server->if_index,

1869

mc->current_server->af, mc);

1870

if(ret == 0){

1871

avahi_simple_poll_quit(s);

1872

return 0;

1873

}

1874

ret = clock_gettime(CLOCK_MONOTONIC,

1875

&mc->current_server->last_seen);

1876

if(ret == -1){

1877

perror_plus("clock_gettime");

1878

return -1;

1879

}

1880

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

1881

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

1882

servers, but don't block */

1883

}

1884

1885

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

1886

}

1887

if(ret != 0){

1888

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

1889

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

1890

}

1891

}

1892

}

1893

}

1894

1895

__attribute__((nonnull))

1896

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

1897

const float delay){

1898

struct dirent **direntries = NULL;

1899

if(hookdir_fd == -1){

1900

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1901

| O_CLOEXEC);

1902

if(hookdir_fd == -1){

1903

if(errno == ENOENT){

1904

if(debug){

1905

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

1906

" found\n", hookdir);

1907

}

1908

} else {

1909

perror_plus("open");

1910

}

1911

return;

1912

}

1913

}

1914

#ifdef __GLIBC__

1915

#if __GLIBC_PREREQ(2, 15)

1916

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

1917

runnable_hook, alphasort);

1918

#else /* not __GLIBC_PREREQ(2, 15) */

1919

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

1920

alphasort);

1921

#endif /* not __GLIBC_PREREQ(2, 15) */

1922

#else /* not __GLIBC__ */

1923

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

1924

alphasort);

1925

#endif /* not __GLIBC__ */

1926

if(numhooks == -1){

1927

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1942

}

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

if(ret == -1){

1989

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1994

free(delaystring);

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

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

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

2063

} else {

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

2083

}

2084

2085

__attribute__((nonnull, warn_unused_result))

2086

error_t bring_up_interface(const char *const interface,

2087

const float delay){

2088

error_t old_errno = errno;

2089

int ret;

2090

struct ifreq network;

2091

unsigned int if_index = if_nametoindex(interface);

2092

if(if_index == 0){

2093

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

2094

errno = old_errno;

2095

return ENXIO;

2096

}

2097

2098

if(quit_now){

2099

errno = old_errno;

2100

return EINTR;

2101

}

2102

2103

if(not interface_is_up(interface)){

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

2106

ret_errno = errno;

2107

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

2108

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

2109

errno = old_errno;

2110

return ret_errno;

2111

}

2112

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

2113

2114

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

2115

if(sd == -1){

2116

ret_errno = errno;

2117

perror_plus("socket");

2118

errno = old_errno;

2119

return ret_errno;

2120

}

2121

2122

if(quit_now){

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

2127

errno = old_errno;

2128

return EINTR;

2129

}

2130

2131

if(debug){

2132

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

2133

interface);

2134

}

2135

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

2142

2143

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

2155

}

2156

#endif /* __linux__ */

2157

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

2158

ioctl_errno = errno;

2159

#ifdef __linux__

2160

if(restore_loglevel){

2161

ret_linux = klogctl(7, NULL, 0);

2162

if(ret_linux == -1){

2163

perror_plus("klogctl");

2164

}

2165

}

2166

#endif /* __linux__ */

2167

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

2177

2178

/* Close the socket */

2179

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

2180

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

errno = old_errno;

2188

return ioctl_errno;

2189

}

2190

} else if(debug){

2191

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

2192

interface);

2193

}

2194

2195

/* Sleep checking until interface is running.

2196

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

2197

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

2198

if(interface_is_running(interface)){

2199

break;

2200

}

2201

struct timespec sleeptime = { .tv_nsec = 250000000 };

2202

ret = nanosleep(&sleeptime, NULL);

2203

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

2204

perror_plus("nanosleep");

2205

}

2206

}

2207

2208

errno = old_errno;

2209

return 0;

2210

}

2211

2212

__attribute__((nonnull, warn_unused_result))

2213

error_t take_down_interface(const char *const interface){

2214

error_t old_errno = errno;

2215

struct ifreq network;

2216

unsigned int if_index = if_nametoindex(interface);

2217

if(if_index == 0){

2218

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

2219

errno = old_errno;

2220

return ENXIO;

2221

}

2222

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

2224

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

2225

ret_errno = errno;

2226

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

2227

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

2228

errno = old_errno;

2229

return ret_errno;

2230

}

2231

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

2232

2233

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

2234

if(sd == -1){

2235

ret_errno = errno;

2236

perror_plus("socket");

2237

errno = old_errno;

2238

return ret_errno;

2239

}

2240

2241

if(debug){

2242

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

2243

interface);

2244

}

2245

2246

/* Raise privileges */

2247

ret_errno = raise_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to raise privileges");

2251

}

2252

2253

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

2254

ioctl_errno = errno;

2255

2256

/* If raise_privileges() succeeded above */

2257

if(ret_errno == 0){

2258

/* Lower privileges */

2259

ret_errno = lower_privileges();

2260

if(ret_errno != 0){

2261

errno = ret_errno;

2262

perror_plus("Failed to lower privileges");

2263

}

2264

}

2265

2266

/* Close the socket */

2267

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

2268

if(ret == -1){

2269

perror_plus("close");

2270

}

2271

2272

if(ret_setflags == -1){

2273

errno = ioctl_errno;

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

errno = old_errno;

2276

return ioctl_errno;

2277

}

2278

} else if(debug){

2279

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

2280

interface);

2281

}

2282

2283

errno = old_errno;

2284

return 0;

1021

2285

}

1022

2286

1023

2287

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

2288

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

2289

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

2290

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2291

.interfaces = NULL, .interfaces_size = 0 };

1024

2292

AvahiSServiceBrowser *sb = NULL;

1025

int error;

2293

error_t ret_errno;

1026

2294

int ret;

1027

2295

intmax_t tmpmax;

1028

2296

char *tmp;

1029

2297

int exitcode = EXIT_SUCCESS;

1030

const char *interface = "eth0";

1031

struct ifreq network;

1032

int sd = -1;

1033

bool take_down_interface = false;

1034

uid_t uid;

1035

gid_t gid;

1036

char *connect_to = NULL;

1037

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

1038

bool tempdir_created = false;

2298

char *interfaces_to_take_down = NULL;

2299

size_t interfaces_to_take_down_size = 0;

2300

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

2301

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

2302

char *tempdir = NULL;

1039

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1040

2304

const char *seckey = PATHDIR "/" SECKEY;

1041

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

1042

2308

1043

2309

bool gnutls_initialized = false;

1044

2310

bool gpgme_initialized = false;

1045

2311

float delay = 2.5f;

2312

double retry_interval = 10; /* 10s between trying a server and

2313

retrying the same server again */

1046

2314

1047

2315

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1048

2316

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1054

2322

errno = 0;

1055

2323

ret = setgid(gid);

1056

2324

if(ret == -1){

1057

perror("setgid");

2325

perror_plus("setgid");

1058

2326

}

1059

2327

1060

2328

/* Lower user privileges (temporarily) */

1061

2329

errno = 0;

1062

2330

ret = seteuid(uid);

1063

2331

if(ret == -1){

1064

perror("seteuid");

2332

perror_plus("seteuid");

1065

2333

}

1066

2334

1067

2335

if(quit_now){

1094

2362

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

1095

2363

" Diffie-Hellman key exchange",

1096

2364

.group = 2 },

2365

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

2366

.arg = "FILE",

2367

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

2368

" for the Diffie-Hellman key exchange",

2369

.group = 2 },

1097

2370

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

1098

2371

.arg = "STRING",

1099

2372

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

1102

2375

.arg = "SECONDS",

1103

2376

.doc = "Maximum delay to wait for interface startup",

1104

2377

.group = 2 },

2378

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

2379

.arg = "SECONDS",

2380

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

2381

.group = 2 },

2382

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

2383

.arg = "DIR",

2384

.doc = "Directory where network hooks are located",

2385

.group = 2 },

1105

2386

/*

1106

2387

* These reproduce what we would get without ARGP_NO_HELP

1107

2388

*/

1125

2406

connect_to = arg;

1126

2407

break;

1127

2408

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

1128

interface = arg;

2409

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

2410

arg, (int)',');

2411

if(ret_errno != 0){

2412

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

2413

}

1129

2414

break;

1130

2415

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

1131

2416

seckey = arg;

1142

2427

}

1143

2428

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

1144

2429

break;

2430

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

2431

dh_params_file = arg;

2432

break;

1145

2433

case 130: /* --priority */

1146

2434

mc.priority = arg;

1147

2435

break;

1151

2439

if(errno != 0 or tmp == arg or *tmp != '\0'){

1152

2440

argp_error(state, "Bad delay");

1153

2441

}

2442

case 132: /* --retry */

2443

errno = 0;

2444

retry_interval = strtod(arg, &tmp);

2445

if(errno != 0 or tmp == arg or *tmp != '\0'

2446

or (retry_interval * 1000) > INT_MAX

2447

or retry_interval < 0){

2448

argp_error(state, "Bad retry interval");

2449

}

2450

break;

2451

case 133: /* --network-hook-dir */

2452

hookdir = arg;

1154

2453

break;

1155

2454

/*

1156

2455

* These reproduce what we would get without ARGP_NO_HELP

1163

2462

argp_state_help(state, state->out_stream,

1164

2463

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1165

2464

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

1166

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

2465

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

1167

2466

exit(argp_err_exit_status);

1168

2467

break;

1169

2468

default:

1184

2483

case ENOMEM:

1185

2484

default:

1186

2485

errno = ret;

1187

perror("argp_parse");

2486

perror_plus("argp_parse");

1188

2487

exitcode = EX_OSERR;

1189

2488

goto end;

1190

2489

case EINVAL:

1193

2492

}

1194

2493

}

1195

2494

2495

{

2496

/* Work around Debian bug #633582:

2497

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

2498

2499

/* Re-raise privileges */

2500

ret_errno = raise_privileges();

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("Failed to raise privileges");

2504

} else {

2505

struct stat st;

2506

2507

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

2508

int seckey_fd = open(seckey, O_RDONLY);

2509

if(seckey_fd == -1){

2510

perror_plus("open");

2511

} else {

2512

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

2513

if(ret == -1){

2514

perror_plus("fstat");

2515

} else {

2516

if(S_ISREG(st.st_mode)

2517

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

2518

ret = fchown(seckey_fd, uid, gid);

2519

if(ret == -1){

2520

perror_plus("fchown");

2521

}

2522

}

2523

}

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

}

2526

}

2527

2528

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

2529

int pubkey_fd = open(pubkey, O_RDONLY);

2530

if(pubkey_fd == -1){

2531

perror_plus("open");

2532

} else {

2533

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

2534

if(ret == -1){

2535

perror_plus("fstat");

2536

} else {

2537

if(S_ISREG(st.st_mode)

2538

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

2539

ret = fchown(pubkey_fd, uid, gid);

2540

if(ret == -1){

2541

perror_plus("fchown");

2542

}

2543

}

2544

}

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

}

2547

}

2548

2549

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

2550

int dhparams_fd = open(dh_params_file, O_RDONLY);

2551

if(dhparams_fd == -1){

2552

perror_plus("open");

2553

} else {

2554

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

2555

if(ret == -1){

2556

perror_plus("fstat");

2557

} else {

2558

if(S_ISREG(st.st_mode)

2559

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

2560

ret = fchown(dhparams_fd, uid, gid);

2561

if(ret == -1){

2562

perror_plus("fchown");

2563

}

2564

}

2565

}

2566

TEMP_FAILURE_RETRY(close(dhparams_fd));

2567

}

2568

}

2569

2570

/* Lower privileges */

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

2575

}

2576

}

2577

}

2578

2579

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

2580

{

2581

char *interface = NULL;

2582

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

2583

interface))){

2584

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

2585

and if_nametoindex(interface) == 0){

2586

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

2587

fprintf_plus(stderr, "Not using nonexisting interface"

2588

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

2589

}

2590

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

2591

interface = NULL;

2592

}

2593

}

2594

}

2595

2596

/* Run network hooks */

2597

{

2598

if(mc.interfaces != NULL){

2599

interfaces_hooks = malloc(mc.interfaces_size);

2600

if(interfaces_hooks == NULL){

2601

perror_plus("malloc");

2602

goto end;

2603

}

2604

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

2605

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

2606

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2609

}

2610

1196

2611

if(not debug){

1197

2612

avahi_set_log_function(empty_log);

1198

2613

}

1201

2616

from the signal handler */

1202

2617

/* Initialize the pseudo-RNG for Avahi */

1203

2618

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

1204

mc.simple_poll = avahi_simple_poll_new();

1205

if(mc.simple_poll == NULL){

1206

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

2619

simple_poll = avahi_simple_poll_new();

2620

if(simple_poll == NULL){

2621

fprintf_plus(stderr,

2622

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

1207

2623

exitcode = EX_UNAVAILABLE;

1208

2624

goto end;

1209

2625

}

1211

2627

sigemptyset(&sigterm_action.sa_mask);

1212

2628

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1213

2629

if(ret == -1){

1214

perror("sigaddset");

2630

perror_plus("sigaddset");

1215

2631

exitcode = EX_OSERR;

1216

2632

goto end;

1217

2633

}

1218

2634

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1219

2635

if(ret == -1){

1220

perror("sigaddset");

2636

perror_plus("sigaddset");

1221

2637

exitcode = EX_OSERR;

1222

2638

goto end;

1223

2639

}

1224

2640

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1225

2641

if(ret == -1){

1226

perror("sigaddset");

2642

perror_plus("sigaddset");

1227

2643

exitcode = EX_OSERR;

1228

2644

goto end;

1229

2645

}

1233

2649

*/

1234

2650

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1235

2651

if(ret == -1){

1236

perror("sigaction");

2652

perror_plus("sigaction");

1237

2653

return EX_OSERR;

1238

2654

}

1239

2655

if(old_sigterm_action.sa_handler != SIG_IGN){

1240

2656

ret = sigaction(SIGINT, &sigterm_action, NULL);

1241

2657

if(ret == -1){

1242

perror("sigaction");

2658

perror_plus("sigaction");

1243

2659

exitcode = EX_OSERR;

1244

2660

goto end;

1245

2661

}

1246

2662

}

1247

2663

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1248

2664

if(ret == -1){

1249

perror("sigaction");

2665

perror_plus("sigaction");

1250

2666

return EX_OSERR;

1251

2667

}

1252

2668

if(old_sigterm_action.sa_handler != SIG_IGN){

1253

2669

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1254

2670

if(ret == -1){

1255

perror("sigaction");

2671

perror_plus("sigaction");

1256

2672

exitcode = EX_OSERR;

1257

2673

goto end;

1258

2674

}

1259

2675

}

1260

2676

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1261

2677

if(ret == -1){

1262

perror("sigaction");

2678

perror_plus("sigaction");

1263

2679

return EX_OSERR;

1264

2680

}

1265

2681

if(old_sigterm_action.sa_handler != SIG_IGN){

1266

2682

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1267

2683

if(ret == -1){

1268

perror("sigaction");

1269

exitcode = EX_OSERR;

1270

goto end;

1271

}

1272

}

1273

1274

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

1275

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

1276

if_index = (AvahiIfIndex) if_nametoindex(interface);

1277

if(if_index == 0){

1278

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

1279

exitcode = EX_UNAVAILABLE;

1280

goto end;

1281

}

1282

1283

if(quit_now){

1284

goto end;

1285

}

1286

1287

/* Re-raise priviliges */

1288

errno = 0;

1289

ret = seteuid(0);

1290

if(ret == -1){

1291

perror("seteuid");

1292

}

1293

1294

#ifdef __linux__

1295

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1296

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

1297

ret = klogctl(8, NULL, 5);

1298

bool restore_loglevel = true;

1299

if(ret == -1){

1300

restore_loglevel = false;

1301

perror("klogctl");

1302

}

1303

#endif /* __linux__ */

1304

1305

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1306

if(sd < 0){

1307

perror("socket");

1308

exitcode = EX_OSERR;

1309

#ifdef __linux__

1310

if(restore_loglevel){

1311

ret = klogctl(7, NULL, 0);

1312

if(ret == -1){

1313

perror("klogctl");

1314

}

1315

}

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1323

goto end;

1324

}

1325

strcpy(network.ifr_name, interface);

1326

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

1327

if(ret == -1){

1328

perror("ioctl SIOCGIFFLAGS");

1329

#ifdef __linux__

1330

if(restore_loglevel){

1331

ret = klogctl(7, NULL, 0);

1332

if(ret == -1){

1333

perror("klogctl");

1334

}

1335

}

1336

#endif /* __linux__ */

1337

exitcode = EX_OSERR;

1338

/* Lower privileges */

1339

errno = 0;

1340

ret = seteuid(uid);

1341

if(ret == -1){

1342

perror("seteuid");

1343

}

1344

goto end;

1345

}

1346

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

1347

network.ifr_flags |= IFF_UP;

1348

take_down_interface = true;

1349

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

1350

if(ret == -1){

1351

take_down_interface = false;

1352

perror("ioctl SIOCSIFFLAGS");

1353

exitcode = EX_OSERR;

1354

#ifdef __linux__

1355

if(restore_loglevel){

1356

ret = klogctl(7, NULL, 0);

1357

if(ret == -1){

1358

perror("klogctl");

2684

perror_plus("sigaction");

2685

exitcode = EX_OSERR;

2686

goto end;

2687

}

2688

}

2689

2690

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

2691

if(mc.interfaces == NULL){

2692

struct dirent **direntries = NULL;

2693

/* Look for any good interfaces */

2694

ret = scandir(sys_class_net, &direntries, good_interface,

2695

alphasort);

2696

if(ret >= 1){

2697

/* Add all found interfaces to interfaces list */

2698

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

2699

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

2700

direntries[i]->d_name);

2701

if(ret_errno != 0){

2702

errno = ret_errno;

2703

perror_plus("argz_add");

2704

free(direntries[i]);

2705

continue;

2706

}

2707

if(debug){

2708

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

2709

direntries[i]->d_name);

2710

}

2711

free(direntries[i]);

2712

}

2713

free(direntries);

2714

} else {

2715

if(ret == 0){

2716

free(direntries);

2717

}

2718

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

2719

exitcode = EXIT_FAILURE;

2720

goto end;

2721

}

2722

}

2723

2724

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

2725

{

2726

char *interface = NULL;

2727

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

2728

interface))){

2729

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

2730

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

2731

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

2732

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

2733

interface);

2734

interface = NULL;

2735

while((interface = argz_next(mc.interfaces,

2736

mc.interfaces_size, interface))){

2737

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

2738

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

2739

interface);

2740

interface = NULL;

1359

2741

}

1360

2742

}

1361

#endif /* __linux__ */

1362

/* Lower privileges */

1363

errno = 0;

1364

ret = seteuid(uid);

1365

if(ret == -1){

1366

perror("seteuid");

1367

}

1368

goto end;

1369

}

1370

}

1371

/* sleep checking until interface is running */

1372

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

1373

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

1374

if(ret == -1){

1375

perror("ioctl SIOCGIFFLAGS");

1376

} else if(network.ifr_flags & IFF_RUNNING){

1377

2743

break;

1378

2744

}

1379

struct timespec sleeptime = { .tv_nsec = 250000000 };

1380

ret = nanosleep(&sleeptime, NULL);

1381

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

1382

perror("nanosleep");

1383

}

1384

}

1385

if(not take_down_interface){

1386

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

1387

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

1388

if(ret == -1){

1389

perror("close");

1390

}

1391

}

1392

#ifdef __linux__

1393

if(restore_loglevel){

1394

/* Restores kernel loglevel to default */

1395

ret = klogctl(7, NULL, 0);

1396

if(ret == -1){

1397

perror("klogctl");

1398

}

1399

}

1400

#endif /* __linux__ */

1401

/* Lower privileges */

1402

errno = 0;

1403

if(take_down_interface){

1404

/* Lower privileges */

1405

ret = seteuid(uid);

1406

if(ret == -1){

1407

perror("seteuid");

1408

}

1409

} else {

1410

/* Lower privileges permanently */

1411

ret = setuid(uid);

1412

if(ret == -1){

1413

perror("setuid");

1414

}

1415

}

2745

bool interface_was_up = interface_is_up(interface);

2746

errno = bring_up_interface(interface, delay);

2747

if(not interface_was_up){

2748

if(errno != 0){

2749

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

2750

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

2751

} else {

2752

errno = argz_add(&interfaces_to_take_down,

2753

&interfaces_to_take_down_size,

2754

interface);

2755

if(errno != 0){

2756

perror_plus("argz_add");

2757

}

2758

}

2759

}

2760

}

2761

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

2762

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

2763

}

2764

}

2765

2766

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

2767

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

2768

if(debug){

2769

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

2770

mc.interfaces);

2771

}

2772

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

1416

2773

}

1417

2774

1418

2775

if(quit_now){

1419

2776

goto end;

1420

2777

}

1421

2778

1422

ret = init_gnutls_global(pubkey, seckey);

2779

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

1423

2780

if(ret == -1){

1424

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

2781

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

1425

2782

exitcode = EX_UNAVAILABLE;

1426

2783

goto end;

1427

2784

} else {

1432

2789

goto end;

1433

2790

}

1434

2791

1435

tempdir_created = true;

1436

if(mkdtemp(tempdir) == NULL){

1437

tempdir_created = false;

1438

perror("mkdtemp");

2792

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

2793

tempdir = mkdtemp(run_tempdir);

2794

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

2795

if(debug){

2796

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

2797

run_tempdir, old_tempdir);

2798

}

2799

tempdir = mkdtemp(old_tempdir);

2800

}

2801

if(tempdir == NULL){

2802

perror_plus("mkdtemp");

1439

2803

goto end;

1440

2804

}

1441

2805

1443

2807

goto end;

1444

2808

}

1445

2809

1446

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

1447

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

2810

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

2811

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

1448

2812

exitcode = EX_UNAVAILABLE;

1449

2813

goto end;

1450

2814

} else {

1459

2823

/* Connect directly, do not use Zeroconf */

1460

2824

/* (Mainly meant for debugging) */

1461

2825

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

2826

1462

2827

if(address == NULL){

1463

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

2828

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

1464

2829

exitcode = EX_USAGE;

1465

2830

goto end;

1466

2831

}

1469

2834

goto end;

1470

2835

}

1471

2836

1472

uint16_t port;

2837

in_port_t port;

1473

2838

errno = 0;

1474

2839

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

1475

2840

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

1476

or tmpmax != (uint16_t)tmpmax){

1477

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

2841

or tmpmax != (in_port_t)tmpmax){

2842

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

1478

2843

exitcode = EX_USAGE;

1479

2844

goto end;

1480

2845

}

1481

2846

1482

2847

if(quit_now){

1483

2848

goto end;

1484

2849

}

1485

2850

1486

port = (uint16_t)tmpmax;

2851

port = (in_port_t)tmpmax;

1487

2852

*address = '\0';

1488

address = connect_to;

1489

2853

/* Colon in address indicates IPv6 */

1490

2854

int af;

1491

if(strchr(address, ':') != NULL){

2855

if(strchr(connect_to, ':') != NULL){

1492

2856

af = AF_INET6;

2857

/* Accept [] around IPv6 address - see RFC 5952 */

2858

if(connect_to[0] == '[' and address[-1] == ']')

2859

{

2860

connect_to++;

2861

address[-1] = '\0';

2862

}

1493

2863

} else {

1494

2864

af = AF_INET;

1495

2865

}

2866

address = connect_to;

1496

2867

1497

2868

if(quit_now){

1498

2869

goto end;

1499

2870

}

1500

2871

1501

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

1502

if(ret < 0){

1503

switch(errno){

1504

case ENETUNREACH:

1505

case EHOSTDOWN:

1506

case EHOSTUNREACH:

1507

exitcode = EX_NOHOST;

1508

break;

1509

case EINVAL:

1510

exitcode = EX_USAGE;

1511

break;

1512

case EIO:

1513

exitcode = EX_IOERR;

1514

break;

1515

case EPROTO:

1516

exitcode = EX_PROTOCOL;

1517

break;

1518

default:

1519

exitcode = EX_OSERR;

1520

break;

1521

}

1522

} else {

2872

while(not quit_now){

2873

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

2874

&mc);

2875

if(quit_now or ret == 0){

2876

break;

2877

}

2878

if(debug){

2879

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

2880

(int)retry_interval);

2881

}

2882

sleep((unsigned int)retry_interval);

2883

}

2884

2885

if(not quit_now){

1523

2886

exitcode = EXIT_SUCCESS;

1524

2887

}

2888

1525

2889

goto end;

1526

2890

}

1527

2891

1539

2903

config.publish_domain = 0;

1540

2904

1541

2905

/* Allocate a new server */

1542

mc.server = avahi_server_new(avahi_simple_poll_get

1543

(mc.simple_poll), &config, NULL,

1544

NULL, &error);

2906

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2907

&config, NULL, NULL, &ret_errno);

1545

2908

1546

2909

/* Free the Avahi configuration data */

1547

2910

avahi_server_config_free(&config);

1549

2912

1550

2913

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

1551

2914

if(mc.server == NULL){

1552

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

1553

avahi_strerror(error));

2915

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

2916

avahi_strerror(ret_errno));

1554

2917

exitcode = EX_UNAVAILABLE;

1555

2918

goto end;

1556

2919

}

1562

2925

/* Create the Avahi service browser */

1563

2926

sb = avahi_s_service_browser_new(mc.server, if_index,

1564

2927

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1565

NULL, 0, browse_callback, NULL);

2928

NULL, 0, browse_callback,

2929

(void *)&mc);

1566

2930

if(sb == NULL){

1567

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

1568

avahi_strerror(avahi_server_errno(mc.server)));

2931

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

2932

avahi_strerror(avahi_server_errno(mc.server)));

1569

2933

exitcode = EX_UNAVAILABLE;

1570

2934

goto end;

1571

2935

}

1577

2941

/* Run the main loop */

1578

2942

1579

2943

if(debug){

1580

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

2944

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

1581

2945

}

1582

2946

1583

avahi_simple_poll_loop(mc.simple_poll);

2947

ret = avahi_loop_with_timeout(simple_poll,

2948

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

2949

if(debug){

2950

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

2951

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

2952

}

1584

2953

1585

2954

end:

1586

2955

1587

2956

if(debug){

1588

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

2957

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

1589

2958

}

1590

2959

1591

2960

/* Cleanup things */

2961

free(mc.interfaces);

2962

1592

2963

if(sb != NULL)

1593

2964

avahi_s_service_browser_free(sb);

1594

2965

1595

2966

if(mc.server != NULL)

1596

2967

avahi_server_free(mc.server);

1597

2968

1598

if(mc.simple_poll != NULL)

1599

avahi_simple_poll_free(mc.simple_poll);

2969

if(simple_poll != NULL)

2970

avahi_simple_poll_free(simple_poll);

1600

2971

1601

2972

if(gnutls_initialized){

1602

2973

gnutls_certificate_free_credentials(mc.cred);

1608

2979

gpgme_release(mc.ctx);

1609

2980

}

1610

2981

1611

/* Take down the network interface */

1612

if(take_down_interface){

1613

/* Re-raise priviliges */

1614

errno = 0;

1615

ret = seteuid(0);

1616

if(ret == -1){

1617

perror("seteuid");

1618

}

1619

if(geteuid() == 0){

1620

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

1621

if(ret == -1){

1622

perror("ioctl SIOCGIFFLAGS");

1623

} else if(network.ifr_flags & IFF_UP) {

1624

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

1625

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

1626

if(ret == -1){

1627

perror("ioctl SIOCSIFFLAGS");

1628

}

1629

}

1630

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

1631

if(ret == -1){

1632

perror("close");

1633

}

1634

/* Lower privileges permanently */

1635

errno = 0;

1636

ret = setuid(uid);

1637

if(ret == -1){

1638

perror("setuid");

1639

}

1640

}

1641

}

1642

1643

/* Removes the temp directory used by GPGME */

1644

if(tempdir_created){

1645

DIR *d;

1646

struct dirent *direntry;

1647

d = opendir(tempdir);

1648

if(d == NULL){

1649

if(errno != ENOENT){

1650

perror("opendir");

1651

}

1652

} else {

1653

while(true){

1654

direntry = readdir(d);

1655

if(direntry == NULL){

1656

break;

1657

}

1658

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

1659

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

1660

and (direntry->d_name[1] == '\0'

1661

or (direntry->d_name[1] == '.'

1662

and direntry->d_name[2] == '\0'))){

1663

continue;

1664

}

1665

char *fullname = NULL;

1666

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

1667

direntry->d_name);

1668

if(ret < 0){

1669

perror("asprintf");

1670

continue;

1671

}

1672

ret = remove(fullname);

1673

if(ret == -1){

1674

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

1675

strerror(errno));

1676

}

1677

free(fullname);

1678

}

1679

closedir(d);

1680

}

1681

ret = rmdir(tempdir);

1682

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

1683

perror("rmdir");

2982

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

2983

has seen */

2984

if(mc.current_server != NULL){

2985

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

2986

while(mc.current_server != NULL){

2987

server *next = mc.current_server->next;

2988

#ifdef __GNUC__

2989

#pragma GCC diagnostic push

2990

#pragma GCC diagnostic ignored "-Wcast-qual"

2991

#endif

2992

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

2993

#ifdef __GNUC__

2994

#pragma GCC diagnostic pop

2995

#endif

2996

free(mc.current_server);

2997

mc.current_server = next;

2998

}

2999

}

3000

3001

/* Re-raise privileges */

3002

{

3003

ret_errno = raise_privileges();

3004

if(ret_errno != 0){

3005

errno = ret_errno;

3006

perror_plus("Failed to raise privileges");

3007

} else {

3008

3009

/* Run network hooks */

3010

run_network_hooks("stop", interfaces_hooks != NULL ?

3011

interfaces_hooks : "", delay);

3012

3013

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

3014

{

3015

char *interface = NULL;

3016

while((interface=argz_next(interfaces_to_take_down,

3017

interfaces_to_take_down_size,

3018

interface))){

3019

ret_errno = take_down_interface(interface);

3020

if(ret_errno != 0){

3021

errno = ret_errno;

3022

perror_plus("Failed to take down interface");

3023

}

3024

}

3025

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

3026

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

3027

" down\n");

3028

}

3029

}

3030

}

3031

3032

ret_errno = lower_privileges_permanently();

3033

if(ret_errno != 0){

3034

errno = ret_errno;

3035

perror_plus("Failed to lower privileges permanently");

3036

}

3037

}

3038

3039

free(interfaces_to_take_down);

3040

free(interfaces_hooks);

3041

3042

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

3043

if(tempdir != NULL){

3044

struct dirent **direntries = NULL;

3045

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

3046

| O_NOFOLLOW

3047

| O_DIRECTORY

3048

| O_PATH));

3049

if(tempdir_fd == -1){

3050

perror_plus("open");

3051

} else {

3052

#ifdef __GLIBC__

3053

#if __GLIBC_PREREQ(2, 15)

3054

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

3055

notdotentries, alphasort);

3056

#else /* not __GLIBC_PREREQ(2, 15) */

3057

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

3058

alphasort);

3059

#endif /* not __GLIBC_PREREQ(2, 15) */

3060

#else /* not __GLIBC__ */

3061

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

3062

alphasort);

3063

#endif /* not __GLIBC__ */

3064

if(numentries >= 0){

3065

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

3066

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

3067

if(ret == -1){

3068

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

3069

" \"%s\", 0): %s\n", tempdir,

3070

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

3071

}

3072

free(direntries[i]);

3073

}

3074

3075

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

3076

free(direntries);

3077

if(numentries == -1){

3078

perror_plus("scandir");

3079

}

3080

ret = rmdir(tempdir);

3081

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

3082

perror_plus("rmdir");

3083

}

3084

}

3085

TEMP_FAILURE_RETRY(close(tempdir_fd));

1684

3086

}

1685

3087

}

1686

3088

1691

3093

&old_sigterm_action,

1692

3094

NULL));

1693

3095

if(ret == -1){

1694

perror("sigaction");

3096

perror_plus("sigaction");

1695

3097

}

1696

3098

do {

1697

3099

ret = raise(signal_received);

1698

3100

} while(ret != 0 and errno == EINTR);

1699

3101

if(ret != 0){

1700

perror("raise");

3102

perror_plus("raise");

1701

3103

abort();

1702

3104

}

1703

3105

TEMP_FAILURE_RETRY(pause());