/mandos/trunk : revision 505.2.2

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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

32

/* 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 /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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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() */

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

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stdout, ferror(), remove() */

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

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

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

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strtof(), abort() */

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

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

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asprintf(), strncpy(), strsignal()

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*/

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

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

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

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

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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

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

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

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inet_pton(), connect(),

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getnameinfo() */

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

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inet_pton(), connect() */

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

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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

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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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*/

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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(), _exit(),

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unlinkat() */

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

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setgid(), pause() */

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

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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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init_gnutls_session(),

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

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

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#define SECKEY "seckey.txt"

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#define PUBKEY "pubkey.txt"

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

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bool debug = false;

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static const char mandos_protocol_version[] = "1";

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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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uint16_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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155

} mandos_context;

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156

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

157

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

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

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.dh_bits = 1024, .priority = "SECURE256"

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

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.current_server = NULL };

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162

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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184

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/* Function to use when printing errors */

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167

void perror_plus(const char *print_text){

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int e = errno;

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168

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

188

169

program_invocation_short_name);

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errno = e;

190

170

perror(print_text);

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171

}

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

194

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

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va_list ap;

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va_start (ap, format);

197

198

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

199

program_invocation_short_name));

200

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

201

}

202

203

173

/*

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174

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

205

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

206

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* "buffer_length" is how much is already used.

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177

*/

208

__attribute__((nonnull, warn_unused_result))

209

178

size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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size_t buffer_capacity){

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180

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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

213

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;

181

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

182

if(buffer == NULL){

218

183

return 0;

219

184

}

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*buffer = new_buf;

221

185

buffer_capacity += BUFFER_SIZE;

222

186

}

223

187

return buffer_capacity;

224

188

}

225

189

226

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

227

__attribute__((nonnull, warn_unused_result))

228

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

229

int af, server **current_server){

191

int add_server(const char *ip, uint16_t port,

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AvahiIfIndex if_index,

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int af){

230

194

int ret;

231

195

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

232

196

if(new_server == NULL){

233

197

perror_plus("malloc");

234

return false;

198

return -1;

235

199

}

236

200

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

237

.port = port,

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.if_index = if_index,

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.af = af };

201

.port = port,

202

.if_index = if_index,

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.af = af };

240

204

if(new_server->ip == NULL){

241

205

perror_plus("strdup");

242

free(new_server);

243

return false;

244

}

245

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

246

if(ret == -1){

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

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#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

257

return false;

206

return -1;

258

207

}

259

208

/* Special case of first server */

260

if(*current_server == NULL){

209

if (mc.current_server == NULL){

261

210

new_server->next = new_server;

262

211

new_server->prev = new_server;

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*current_server = new_server;

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mc.current_server = new_server;

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

264

214

} else {

265

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

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new_server->next = *current_server;

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

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new_server->next = mc.current_server;

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new_server->prev = mc.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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}

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return true;

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mc.current_server->prev = new_server;

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}

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

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if(ret == -1){

222

perror_plus("clock_gettime");

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return -1;

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}

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return 0;

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}

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227

274

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/*

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229

* Initialize GPGME.

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*/

277

__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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static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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285

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/*

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

287

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*/

288

bool import_key(const char * const filename){

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bool import_key(const char *filename){

289

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int ret;

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int fd;

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gpgme_data_t pgp_data;

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299

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

300

252

if(rc != GPG_ERR_NO_ERROR){

301

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

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gpgme_strsource(rc), gpgme_strerror(rc));

303

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return false;

304

256

}

305

257

306

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

258

rc = gpgme_op_import(mc.ctx, pgp_data);

307

259

if(rc != GPG_ERR_NO_ERROR){

308

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

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gpgme_strsource(rc), gpgme_strerror(rc));

260

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

261

gpgme_strsource(rc), gpgme_strerror(rc));

310

262

return false;

311

263

}

312

264

313

ret = close(fd);

265

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

314

266

if(ret == -1){

315

267

perror_plus("close");

316

268

}

319

271

}

320

272

321

273

if(debug){

322

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

274

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

323

275

}

324

276

325

277

/* Init GPGME */

326

278

gpgme_check_version(NULL);

327

279

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

328

280

if(rc != GPG_ERR_NO_ERROR){

329

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

330

gpgme_strsource(rc), gpgme_strerror(rc));

281

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

282

gpgme_strsource(rc), gpgme_strerror(rc));

331

283

return false;

332

284

}

333

285

334

286

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

335

287

rc = gpgme_get_engine_info(&engine_info);

336

288

if(rc != GPG_ERR_NO_ERROR){

337

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

338

gpgme_strsource(rc), gpgme_strerror(rc));

289

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

290

gpgme_strsource(rc), gpgme_strerror(rc));

339

291

return false;

340

292

}

341

293

while(engine_info != NULL){

347

299

engine_info = engine_info->next;

348

300

}

349

301

if(engine_info == NULL){

350

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

351

tempdir);

302

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

352

303

return false;

353

304

}

354

305

355

306

/* Create new GPGME "context" */

356

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

307

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

357

308

if(rc != GPG_ERR_NO_ERROR){

358

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

359

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

360

gpgme_strerror(rc));

309

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

310

gpgme_strsource(rc), gpgme_strerror(rc));

361

311

return false;

362

312

}

363

313

372

322

* Decrypt OpenPGP data.

373

323

* Returns -1 on error

374

324

*/

375

__attribute__((nonnull, warn_unused_result))

376

325

static ssize_t pgp_packet_decrypt(const char *cryptotext,

377

326

size_t crypto_size,

378

char **plaintext,

379

mandos_context *mc){

327

char **plaintext){

380

328

gpgme_data_t dh_crypto, dh_plain;

381

329

gpgme_error_t rc;

382

330

ssize_t ret;

384

332

ssize_t plaintext_length = 0;

385

333

386

334

if(debug){

387

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

335

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

388

336

}

389

337

390

338

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

391

339

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

392

340

0);

393

341

if(rc != GPG_ERR_NO_ERROR){

394

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

395

gpgme_strsource(rc), gpgme_strerror(rc));

342

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

343

gpgme_strsource(rc), gpgme_strerror(rc));

396

344

return -1;

397

345

}

398

346

399

347

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

400

348

rc = gpgme_data_new(&dh_plain);

401

349

if(rc != GPG_ERR_NO_ERROR){

402

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

403

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

404

gpgme_strsource(rc), gpgme_strerror(rc));

350

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

351

gpgme_strsource(rc), gpgme_strerror(rc));

405

352

gpgme_data_release(dh_crypto);

406

353

return -1;

407

354

}

408

355

409

356

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

410

357

data buffer */

411

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

358

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

412

359

if(rc != GPG_ERR_NO_ERROR){

413

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

414

gpgme_strsource(rc), gpgme_strerror(rc));

360

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

361

gpgme_strsource(rc), gpgme_strerror(rc));

415

362

plaintext_length = -1;

416

363

if(debug){

417

364

gpgme_decrypt_result_t result;

418

result = gpgme_op_decrypt_result(mc->ctx);

365

result = gpgme_op_decrypt_result(mc.ctx);

419

366

if(result == NULL){

420

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

367

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

421

368

} else {

422

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

423

result->unsupported_algorithm);

424

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

425

result->wrong_key_usage);

369

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

370

result->unsupported_algorithm);

371

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

372

result->wrong_key_usage);

426

373

if(result->file_name != NULL){

427

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

374

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

428

375

}

429

376

gpgme_recipient_t recipient;

430

377

recipient = result->recipients;

431

378

while(recipient != NULL){

432

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

433

gpgme_pubkey_algo_name

434

(recipient->pubkey_algo));

435

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

436

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

437

recipient->status == GPG_ERR_NO_SECKEY

438

? "No" : "Yes");

379

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

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

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

382

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

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

439

385

recipient = recipient->next;

440

386

}

441

387

}

444

390

}

445

391

446

392

if(debug){

447

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

393

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

448

394

}

449

395

450

396

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

457

403

*plaintext = NULL;

458

404

while(true){

459

405

plaintext_capacity = incbuffer(plaintext,

460

(size_t)plaintext_length,

461

plaintext_capacity);

406

(size_t)plaintext_length,

407

plaintext_capacity);

462

408

if(plaintext_capacity == 0){

463

perror_plus("incbuffer");

464

plaintext_length = -1;

465

goto decrypt_end;

409

perror_plus("incbuffer");

410

plaintext_length = -1;

411

goto decrypt_end;

466

412

}

467

413

468

414

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

481

427

}

482

428

483

429

if(debug){

484

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

430

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

485

431

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

486

432

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

487

433

}

498

444

return plaintext_length;

499

445

}

500

446

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

510

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

447

static const char * safer_gnutls_strerror(int value){

448

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

449

-Wunreachable-code */

450

if(ret == NULL)

451

ret = "(unknown)";

452

return ret;

512

453

}

513

454

514

455

/* GnuTLS log function callback */

515

__attribute__((nonnull))

516

456

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

517

457

const char* string){

518

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

458

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

519

459

}

520

460

521

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

522

461

static int init_gnutls_global(const char *pubkeyfilename,

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

462

const char *seckeyfilename){

526

463

int ret;

527

unsigned int uret;

528

464

529

465

if(debug){

530

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

466

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

467

}

468

469

ret = gnutls_global_init();

470

if(ret != GNUTLS_E_SUCCESS){

471

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

472

safer_gnutls_strerror(ret));

473

return -1;

531

474

}

532

475

533

476

if(debug){

539

482

}

540

483

541

484

/* OpenPGP credentials */

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

486

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

487

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

488

safer_gnutls_strerror(ret));

489

gnutls_global_deinit();

546

490

return -1;

547

491

}

548

492

549

493

if(debug){

550

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

551

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

552

pubkeyfilename,

553

seckeyfilename);

494

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

495

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

496

seckeyfilename);

554

497

}

555

498

556

499

ret = gnutls_certificate_set_openpgp_key_file

557

(mc->cred, pubkeyfilename, seckeyfilename,

500

(mc.cred, pubkeyfilename, seckeyfilename,

558

501

GNUTLS_OPENPGP_FMT_BASE64);

559

502

if(ret != GNUTLS_E_SUCCESS){

560

fprintf_plus(stderr,

561

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

562

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

563

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

564

safer_gnutls_strerror(ret));

503

fprintf(stderr,

504

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

505

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

506

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

507

safer_gnutls_strerror(ret));

565

508

goto globalfail;

566

509

}

567

510

568

511

/* GnuTLS server initialization */

569

ret = gnutls_dh_params_init(&mc->dh_params);

570

if(ret != GNUTLS_E_SUCCESS){

571

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

572

" initialization: %s\n",

573

safer_gnutls_strerror(ret));

574

goto globalfail;

575

}

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

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

635

/* Try to read the private key file */

636

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

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

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

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

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

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

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

687

if(ret != GNUTLS_E_SUCCESS){

688

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

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

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

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

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

724

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

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

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

739

mc->dh_bits);

740

}

741

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

742

if(ret != GNUTLS_E_SUCCESS){

743

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

744

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

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

749

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

512

ret = gnutls_dh_params_init(&mc.dh_params);

513

if(ret != GNUTLS_E_SUCCESS){

514

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

515

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

516

goto globalfail;

517

}

518

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

519

if(ret != GNUTLS_E_SUCCESS){

520

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

521

safer_gnutls_strerror(ret));

522

goto globalfail;

523

}

524

525

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

750

526

751

527

return 0;

752

528

753

529

globalfail:

754

530

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

531

gnutls_certificate_free_credentials(mc.cred);

532

gnutls_global_deinit();

533

gnutls_dh_params_deinit(mc.dh_params);

757

534

return -1;

758

535

}

759

536

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

537

static int init_gnutls_session(gnutls_session_t *session){

763

538

int ret;

764

539

/* GnuTLS session creation */

765

540

do {

769

544

}

770

545

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

771

546

if(ret != GNUTLS_E_SUCCESS){

772

fprintf_plus(stderr,

773

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

774

safer_gnutls_strerror(ret));

547

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

548

safer_gnutls_strerror(ret));

775

549

}

776

550

777

551

{

778

552

const char *err;

779

553

do {

780

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

554

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

781

555

if(quit_now){

782

556

gnutls_deinit(*session);

783

557

return -1;

784

558

}

785

559

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

786

560

if(ret != GNUTLS_E_SUCCESS){

787

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

788

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

789

safer_gnutls_strerror(ret));

561

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

562

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

563

safer_gnutls_strerror(ret));

790

564

gnutls_deinit(*session);

791

565

return -1;

792

566

}

794

568

795

569

do {

796

570

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

797

mc->cred);

571

mc.cred);

798

572

if(quit_now){

799

573

gnutls_deinit(*session);

800

574

return -1;

801

575

}

802

576

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

803

577

if(ret != GNUTLS_E_SUCCESS){

804

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

805

safer_gnutls_strerror(ret));

578

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

579

safer_gnutls_strerror(ret));

806

580

gnutls_deinit(*session);

807

581

return -1;

808

582

}

810

584

/* ignore client certificate if any. */

811

585

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

812

586

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

588

813

589

return 0;

814

590

}

815

591

817

593

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

818

594

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

819

595

820

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

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

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

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

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

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

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

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

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

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

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

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

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

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

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

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

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

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

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

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

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

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

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

898

if(devnull == -1){

899

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

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

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

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

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

939

_exit(EX_OSERR);

940

}

941

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

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

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

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

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

963

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

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

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

982

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

983

int errno_raising = 0;

984

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

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

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

990

perror_plus("kill");

991

}

992

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

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

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

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

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

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

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

1014

return false;

1015

}

1016

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

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

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

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

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

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

1038

596

/* Called when a Mandos server is found */

1039

__attribute__((nonnull, warn_unused_result))

1040

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

597

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

1041

598

AvahiIfIndex if_index,

1042

int af, mandos_context *mc){

599

int af){

1043

600

int ret, tcp_sd = -1;

1044

601

ssize_t sret;

1045

struct sockaddr_storage to;

602

union {

603

struct sockaddr_in in;

604

struct sockaddr_in6 in6;

605

} to;

1046

606

char *buffer = NULL;

1047

607

char *decrypted_buffer = NULL;

1048

608

size_t buffer_length = 0;

1051

611

int retval = -1;

1052

612

gnutls_session_t session;

1053

613

int pf; /* Protocol family */

1054

bool route_added = false;

1055

614

1056

615

errno = 0;

1057

616

1068

627

pf = PF_INET;

1069

628

break;

1070

629

default:

1071

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

630

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

1072

631

errno = EINVAL;

1073

632

return -1;

1074

633

}

1075

634

1076

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

1077

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

1078

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

1079

bool match = false;

1080

{

1081

char *interface = NULL;

1082

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

1083

mc->interfaces_size,

1084

interface))){

1085

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

1086

match = true;

1087

break;

1088

}

1089

}

1090

}

1091

if(not match){

1092

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

1093

connect to the server */

1094

if(debug){

1095

char interface[IF_NAMESIZE];

1096

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

1097

perror_plus("if_indextoname");

1098

} else {

1099

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

1100

" \"%s\"\n",

1101

if_indextoname((unsigned int)if_index,

1102

interface));

1103

}

1104

}

1105

return -1;

1106

}

1107

}

1108

1109

ret = init_gnutls_session(&session, mc);

635

ret = init_gnutls_session(&session);

1110

636

if(ret != 0){

1111

637

return -1;

1112

638

}

1113

639

1114

640

if(debug){

1115

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

1116

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

641

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

642

"\n", ip, port);

1117

643

}

1118

644

1119

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

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

646

if(tcp_sd < 0){

1121

647

int e = errno;

1122

648

perror_plus("socket");

1129

655

goto mandos_end;

1130

656

}

1131

657

658

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

1132

659

if(af == AF_INET6){

1133

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

1134

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

1135

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

660

to.in6.sin6_family = (sa_family_t)af;

661

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

1136

662

} else { /* IPv4 */

1137

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

1138

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

1139

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

663

to.in.sin_family = (sa_family_t)af;

664

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

1140

665

}

1141

666

if(ret < 0 ){

1142

667

int e = errno;

1146

671

}

1147

672

if(ret == 0){

1148

673

int e = errno;

1149

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

674

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

1150

675

errno = e;

1151

676

goto mandos_end;

1152

677

}

1153

678

if(af == AF_INET6){

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

679

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

680

-Wconversion and

681

-Wunreachable-code */

682

683

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

684

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

685

-Wunreachable-code*/

1157

686

if(if_index == AVAHI_IF_UNSPEC){

1158

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

1159

" incomplete without a network interface\n");

687

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

688

" without a network interface\n");

1160

689

errno = EINVAL;

1161

690

goto mandos_end;

1162

691

}

1163

692

/* Set the network interface number as scope */

1164

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

693

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

694

}

1166

695

} else {

1167

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

696

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

697

-Wconversion and

698

-Wunreachable-code */

1168

699

}

1169

700

1170

701

if(quit_now){

1178

709

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

1179

710

perror_plus("if_indextoname");

1180

711

} else {

1181

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

1182

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

712

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

713

ip, interface, port);

1183

714

}

1184

715

} else {

1185

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

1186

ip, (uintmax_t)port);

716

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

717

port);

1187

718

}

1188

719

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

720

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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) or (errno == EHOSTUNREACH))

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

https://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;

721

const char *pcret;

722

if(af == AF_INET6){

723

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

724

sizeof(addrstr));

725

} else {

726

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

727

sizeof(addrstr));

728

}

729

if(pcret == NULL){

730

perror_plus("inet_ntop");

731

} else {

732

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

733

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

734

}

735

}

736

}

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

743

if(af == AF_INET6){

744

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

745

} else {

746

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

747

}

748

if(ret < 0){

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

1270

760

}

1271

761

1272

762

const char *out = mandos_protocol_version;

1274

764

while(true){

1275

765

size_t out_size = strlen(out);

1276

766

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

1277

out_size - written));

767

out_size - written));

1278

768

if(ret == -1){

1279

769

int e = errno;

1280

770

perror_plus("write");

1300

790

}

1301

791

1302

792

if(debug){

1303

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

793

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

1304

794

}

1305

795

1306

796

if(quit_now){

1308

798

goto mandos_end;

1309

799

}

1310

800

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);

801

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

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1316

803

1317

804

if(quit_now){

1318

805

errno = EINTR;

1329

816

1330

817

if(ret != GNUTLS_E_SUCCESS){

1331

818

if(debug){

1332

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

819

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

1333

820

gnutls_perror(ret);

1334

821

}

1335

822

errno = EPROTO;

1339

826

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

1340

827

1341

828

if(debug){

1342

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1343

" %s\n", ip);

829

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

830

ip);

1344

831

}

1345

832

1346

833

while(true){

1351

838

}

1352

839

1353

840

buffer_capacity = incbuffer(&buffer, buffer_length,

1354

buffer_capacity);

841

buffer_capacity);

1355

842

if(buffer_capacity == 0){

1356

843

int e = errno;

1357

844

perror_plus("incbuffer");

1384

871

}

1385

872

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

1386

873

if(ret < 0){

1387

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

1388

"***\n");

874

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

1389

875

gnutls_perror(ret);

1390

876

errno = EPROTO;

1391

877

goto mandos_end;

1392

878

}

1393

879

break;

1394

880

default:

1395

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

1396

" encrypted session with Mandos server\n");

881

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

882

" encrypted session with Mandos server\n");

1397

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

1398

884

errno = EIO;

1399

885

goto mandos_end;

1404

890

}

1405

891

1406

892

if(debug){

1407

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

893

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

1408

894

}

1409

895

1410

896

if(quit_now){

1422

908

1423

909

if(buffer_length > 0){

1424

910

ssize_t decrypted_buffer_size;

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

912

buffer_length,

913

&decrypted_buffer);

1427

914

if(decrypted_buffer_size >= 0){

1428

915

1429

clearerr(stdout);

1430

916

written = 0;

1431

917

while(written < (size_t) decrypted_buffer_size){

1432

918

if(quit_now){

1440

926

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

1441

927

int e = errno;

1442

928

if(debug){

1443

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

1444

strerror(errno));

929

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

930

strerror(errno));

1445

931

}

1446

932

errno = e;

1447

933

goto mandos_end;

1448

934

}

1449

935

written += (size_t)ret;

1450

936

}

1451

ret = fflush(stdout);

1452

if(ret != 0){

1453

int e = errno;

1454

if(debug){

1455

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

1456

strerror(errno));

1457

}

1458

errno = e;

1459

goto mandos_end;

1460

}

1461

937

retval = 0;

1462

938

}

1463

939

}

1466

942

1467

943

mandos_end:

1468

944

{

1469

if(route_added){

1470

if(not delete_local_route(ip, if_index)){

1471

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

1472

" interface %d", ip, if_index);

1473

}

1474

}

1475

945

int e = errno;

1476

946

free(decrypted_buffer);

1477

947

free(buffer);

1478

948

if(tcp_sd >= 0){

1479

ret = close(tcp_sd);

949

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

1480

950

}

1481

951

if(ret == -1){

1482

952

if(e == 0){

1507

977

AVAHI_GCC_UNUSED AvahiStringList *txt,

1508

978

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1509

979

flags,

1510

void *mc){

1511

if(r == NULL){

1512

return;

1513

}

980

AVAHI_GCC_UNUSED void* userdata){

981

assert(r);

1514

982

1515

983

/* Called whenever a service has been resolved successfully or

1516

984

timed out */

1517

985

1518

986

if(quit_now){

1519

avahi_s_service_resolver_free(r);

1520

987

return;

1521

988

}

1522

989

1523

990

switch(event){

1524

991

default:

1525

992

case AVAHI_RESOLVER_FAILURE:

1526

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

1527

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

1528

domain,

1529

avahi_strerror(avahi_server_errno

1530

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

993

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

994

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

995

avahi_strerror(avahi_server_errno(mc.server)));

1531

996

break;

1532

997

1533

998

case AVAHI_RESOLVER_FOUND:

1535

1000

char ip[AVAHI_ADDRESS_STR_MAX];

1536

1001

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

1537

1002

if(debug){

1538

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

1539

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

1540

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

1003

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

1004

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

1005

ip, (intmax_t)interface, port);

1541

1006

}

1542

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

1543

interface,

1544

avahi_proto_to_af(proto),

1545

mc);

1007

int ret = start_mandos_communication(ip, port, interface,

1008

avahi_proto_to_af(proto));

1546

1009

if(ret == 0){

1547

avahi_simple_poll_quit(simple_poll);

1010

avahi_simple_poll_quit(mc.simple_poll);

1548

1011

} else {

1549

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

1550

avahi_proto_to_af(proto),

1551

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

1552

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

1553

" list\n", name);

1554

}

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

1555

1014

}

1556

1015

}

1557

1016

}

1567

1026

const char *domain,

1568

1027

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1569

1028

flags,

1570

void *mc){

1571

if(b == NULL){

1572

return;

1573

}

1029

AVAHI_GCC_UNUSED void* userdata){

1030

assert(b);

1574

1031

1575

1032

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

1576

1033

is removed from the LAN */

1583

1040

default:

1584

1041

case AVAHI_BROWSER_FAILURE:

1585

1042

1586

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

1587

avahi_strerror(avahi_server_errno

1588

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

1589

avahi_simple_poll_quit(simple_poll);

1043

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

1044

avahi_strerror(avahi_server_errno(mc.server)));

1045

avahi_simple_poll_quit(mc.simple_poll);

1590

1046

return;

1591

1047

1592

1048

case AVAHI_BROWSER_NEW:

1595

1051

the callback function is called the Avahi server will free the

1596

1052

resolver for us. */

1597

1053

1598

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

1599

interface, protocol, name, type,

1600

domain, protocol, 0,

1601

resolve_callback, mc) == NULL)

1602

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

1603

" %s\n", name,

1604

avahi_strerror(avahi_server_errno

1605

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

1054

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

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

1057

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

1058

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

1606

1059

break;

1607

1060

1608

1061

case AVAHI_BROWSER_REMOVE:

1611

1064

case AVAHI_BROWSER_ALL_FOR_NOW:

1612

1065

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1613

1066

if(debug){

1614

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

1615

" searching...\n");

1067

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

1616

1068

}

1617

1069

break;

1618

1070

}

1627

1079

signal_received = sig;

1628

1080

int old_errno = errno;

1629

1081

/* set main loop to exit */

1630

if(simple_poll != NULL){

1631

avahi_simple_poll_quit(simple_poll);

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1632

1084

}

1633

1085

errno = old_errno;

1634

1086

}

1635

1087

1636

__attribute__((nonnull, warn_unused_result))

1637

1088

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

1638

1089

int ret;

1639

int old_errno;

1640

1090

1641

1091

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

1642

1092

if(s < 0){

1643

old_errno = errno;

1644

1093

perror_plus("socket");

1645

errno = old_errno;

1646

1094

return false;

1647

1095

}

1648

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

1649

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

1096

strcpy(ifr->ifr_name, ifname);

1650

1097

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1651

1098

if(ret == -1){

1652

1099

if(debug){

1653

old_errno = errno;

1654

1100

perror_plus("ioctl SIOCGIFFLAGS");

1655

errno = old_errno;

1656

1101

}

1657

1102

return false;

1658

1103

}

1659

1104

return true;

1660

1105

}

1661

1106

1662

__attribute__((nonnull, warn_unused_result))

1663

1107

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

1664

1108

1665

1109

/* Reject the loopback device */

1666

1110

if(ifr->ifr_flags & IFF_LOOPBACK){

1667

1111

if(debug){

1668

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

1669

ifname);

1112

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

1113

ifname);

1670

1114

}

1671

1115

return false;

1672

1116

}

1673

1117

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

1674

1118

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

1675

1119

if(debug){

1676

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

1677

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

1120

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1121

ifname);

1678

1122

}

1679

1123

return true;

1680

1124

}

1681

1125

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

1682

1126

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

1683

1127

if(debug){

1684

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1685

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

1128

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1129

ifname);

1686

1130

}

1687

1131

return false;

1688

1132

}

1689

1133

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

1690

1134

if(ifr->ifr_flags & IFF_NOARP){

1691

1135

if(debug){

1692

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

1693

ifname);

1136

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n", ifname);

1694

1137

}

1695

1138

return false;

1696

1139

}

1697

1140

1698

1141

/* Accept this device */

1699

1142

if(debug){

1700

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

1143

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

1701

1144

}

1702

1145

return true;

1703

1146

}

1707

1150

* corresponds to an acceptable network device.

1708

1151

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

1709

1152

*/

1710

__attribute__((nonnull, warn_unused_result))

1711

1153

int good_interface(const struct dirent *if_entry){

1154

int ret;

1712

1155

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

1713

1156

return 0;

1714

1157

}

1715

1716

1158

struct ifreq ifr;

1159

1717

1160

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

1718

if(debug){

1719

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

1720

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

1721

}

1722

1161

return 0;

1723

1162

}

1724

1163

1728

1167

return 1;

1729

1168

}

1730

1169

1731

/*

1732

* This function determines if a network interface is up.

1733

*/

1734

__attribute__((nonnull, warn_unused_result))

1735

bool interface_is_up(const char *interface){

1736

struct ifreq ifr;

1737

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

1738

if(debug){

1739

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

1740

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

1741

}

1742

return false;

1743

}

1744

1745

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

1746

}

1747

1748

/*

1749

* This function determines if a network interface is running

1750

*/

1751

__attribute__((nonnull, warn_unused_result))

1752

bool interface_is_running(const char *interface){

1753

struct ifreq ifr;

1754

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

1755

if(debug){

1756

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

1757

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

1758

}

1759

return false;

1760

}

1761

1762

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

1763

}

1764

1765

__attribute__((nonnull, pure, warn_unused_result))

1766

1170

int notdotentries(const struct dirent *direntry){

1767

1171

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

1768

1172

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

1774

1178

return 1;

1775

1179

}

1776

1180

1777

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

1778

__attribute__((nonnull, warn_unused_result))

1779

int runnable_hook(const struct dirent *direntry){

1780

int ret;

1781

size_t sret;

1782

struct stat st;

1783

1784

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

1785

/* Empty name? */

1786

return 0;

1787

}

1788

1789

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

1790

"abcdefghijklmnopqrstuvwxyz"

1791

"0123456789"

1792

"_.-");

1793

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

1794

/* Contains non-allowed characters */

1795

if(debug){

1796

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

1797

direntry->d_name);

1798

}

1799

return 0;

1800

}

1801

1802

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

1803

if(ret == -1){

1804

if(debug){

1805

perror_plus("Could not stat hook");

1806

}

1807

return 0;

1808

}

1809

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

1810

/* Not a regular file */

1811

if(debug){

1812

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

1813

direntry->d_name);

1814

}

1815

return 0;

1816

}

1817

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

1818

/* Not executable */

1819

if(debug){

1820

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

1821

direntry->d_name);

1822

}

1823

return 0;

1824

}

1825

if(debug){

1826

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

1827

direntry->d_name);

1828

}

1829

return 1;

1830

}

1831

1832

__attribute__((nonnull, warn_unused_result))

1833

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1834

mandos_context *mc){

1181

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1835

1182

int ret;

1836

1183

struct timespec now;

1837

1184

struct timespec waited_time;

1838

1185

intmax_t block_time;

1839

1186

1840

1187

while(true){

1841

if(mc->current_server == NULL){

1842

if(debug){

1843

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

1844

" No timeout!\n");

1188

if(mc.current_server == NULL){

1189

if (debug){

1190

fprintf(stderr,

1191

"Wait until first server is found. No timeout!\n");

1845

1192

}

1846

1193

ret = avahi_simple_poll_iterate(s, -1);

1847

1194

} else {

1848

if(debug){

1849

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

1850

" it, or wait\n");

1195

if (debug){

1196

fprintf(stderr, "Check current_server if we should run it,"

1197

" or wait\n");

1851

1198

}

1852

1199

/* the current time */

1853

1200

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1858

1205

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

1859

1206

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

1860

1207

waited_time.tv_sec = (now.tv_sec

1861

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

1208

- mc.current_server->last_seen.tv_sec);

1862

1209

waited_time.tv_nsec = (now.tv_nsec

1863

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

1210

- mc.current_server->last_seen.tv_nsec);

1864

1211

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

1865

1212

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

1866

1213

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

1868

1215

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

1869

1216

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

1870

1217

1871

if(debug){

1872

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

1873

block_time);

1218

if (debug){

1219

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1874

1220

}

1875

1221

1876

1222

if(block_time <= 0){

1877

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

1878

mc->current_server->port,

1879

mc->current_server->if_index,

1880

mc->current_server->af, mc);

1223

ret = start_mandos_communication(mc.current_server->ip,

1224

mc.current_server->port,

1225

mc.current_server->if_index,

1226

mc.current_server->af);

1881

1227

if(ret == 0){

1882

avahi_simple_poll_quit(s);

1228

avahi_simple_poll_quit(mc.simple_poll);

1883

1229

return 0;

1884

1230

}

1885

1231

ret = clock_gettime(CLOCK_MONOTONIC,

1886

&mc->current_server->last_seen);

1232

&mc.current_server->last_seen);

1887

1233

if(ret == -1){

1888

1234

perror_plus("clock_gettime");

1889

1235

return -1;

1890

1236

}

1891

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

1237

mc.current_server = mc.current_server->next;

1892

1238

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

1893

1239

servers, but don't block */

1894

1240

}

1896

1242

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

1897

1243

}

1898

1244

if(ret != 0){

1899

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

1245

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

1900

1246

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

1901

1247

}

1902

1248

}

1903

1249

}

1904

1250

}

1905

1251

1906

__attribute__((nonnull))

1907

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

1908

const float delay){

1909

struct dirent **direntries = NULL;

1910

if(hookdir_fd == -1){

1911

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1912

| O_CLOEXEC);

1913

if(hookdir_fd == -1){

1914

if(errno == ENOENT){

1915

if(debug){

1916

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

1917

" found\n", hookdir);

1918

}

1919

} else {

1920

perror_plus("open");

1921

}

1922

return;

1923

}

1924

}

1925

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

1926

runnable_hook, alphasort);

1927

if(numhooks == -1){

1928

perror_plus("scandir");

1929

return;

1930

}

1931

struct dirent *direntry;

1932

int ret;

1933

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

1934

if(devnull == -1){

1935

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

1936

return;

1937

}

1938

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

1939

direntry = direntries[i];

1940

if(debug){

1941

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

1942

direntry->d_name);

1943

}

1944

pid_t hook_pid = fork();

1945

if(hook_pid == 0){

1946

/* Child */

1947

/* Raise privileges */

1948

errno = raise_privileges_permanently();

1949

if(errno != 0){

1950

perror_plus("Failed to raise privileges");

1951

_exit(EX_NOPERM);

1952

}

1953

/* Set group */

1954

errno = 0;

1955

ret = setgid(0);

1956

if(ret == -1){

1957

perror_plus("setgid");

1958

_exit(EX_NOPERM);

1959

}

1960

/* Reset supplementary groups */

1961

errno = 0;

1962

ret = setgroups(0, NULL);

1963

if(ret == -1){

1964

perror_plus("setgroups");

1965

_exit(EX_NOPERM);

1966

}

1967

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

1968

if(ret == -1){

1969

perror_plus("setenv");

1970

_exit(EX_OSERR);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

char *delaystring;

1988

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

1989

if(ret == -1){

1990

perror_plus("asprintf");

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1995

free(delaystring);

1996

perror_plus("setenv");

1997

_exit(EX_OSERR);

1998

}

1999

free(delaystring);

2000

if(connect_to != NULL){

2001

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

2002

if(ret == -1){

2003

perror_plus("setenv");

2004

_exit(EX_OSERR);

2005

}

2006

}

2007

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

2008

direntry->d_name,

2009

O_RDONLY));

2010

if(hook_fd == -1){

2011

perror_plus("openat");

2012

_exit(EXIT_FAILURE);

2013

}

2014

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

2015

perror_plus("close");

2016

_exit(EXIT_FAILURE);

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

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

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

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

2031

_exit(EX_OSERR);

2032

}

2033

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

2034

environ) == -1){

2035

perror_plus("fexecve");

2036

_exit(EXIT_FAILURE);

2037

}

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

2044

int status;

2045

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

2046

perror_plus("waitpid");

2047

free(direntry);

2048

continue;

2049

}

2050

if(WIFEXITED(status)){

2051

if(WEXITSTATUS(status) != 0){

2052

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

2053

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

2054

WEXITSTATUS(status));

2055

free(direntry);

2056

continue;

2057

}

2058

} else if(WIFSIGNALED(status)){

2059

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

2060

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

2061

WTERMSIG(status));

2062

free(direntry);

2063

continue;

2064

} else {

2065

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

2066

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

2067

free(direntry);

2068

continue;

2069

}

2070

}

2071

if(debug){

2072

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

2073

direntry->d_name);

2074

}

2075

free(direntry);

2076

}

2077

free(direntries);

2078

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

2079

perror_plus("close");

2080

} else {

2081

hookdir_fd = -1;

2082

}

2083

close(devnull);

2084

}

2085

2086

__attribute__((nonnull, warn_unused_result))

2087

int bring_up_interface(const char *const interface,

2088

const float delay){

2089

int old_errno = errno;

2090

int ret;

2091

struct ifreq network;

2092

unsigned int if_index = if_nametoindex(interface);

2093

if(if_index == 0){

2094

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

2095

errno = old_errno;

2096

return ENXIO;

2097

}

2098

2099

if(quit_now){

2100

errno = old_errno;

2101

return EINTR;

2102

}

2103

2104

if(not interface_is_up(interface)){

2105

int ret_errno = 0;

2106

int ioctl_errno = 0;

2107

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

2108

ret_errno = errno;

2109

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

2110

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

2111

errno = old_errno;

2112

return ret_errno;

2113

}

2114

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

2115

2116

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

2117

if(sd == -1){

2118

ret_errno = errno;

2119

perror_plus("socket");

2120

errno = old_errno;

2121

return ret_errno;

2122

}

2123

2124

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

2129

errno = old_errno;

2130

return EINTR;

2131

}

2132

2133

if(debug){

2134

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

2135

interface);

2136

}

2137

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

2144

2145

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

2157

}

2158

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

2161

#ifdef __linux__

2162

if(restore_loglevel){

2163

ret_linux = klogctl(7, NULL, 0);

2164

if(ret_linux == -1){

2165

perror_plus("klogctl");

2166

}

2167

}

2168

#endif /* __linux__ */

2169

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

2179

2180

/* Close the socket */

2181

ret = close(sd);

2182

if(ret == -1){

2183

perror_plus("close");

2184

}

2185

2186

if(ret_setflags == -1){

2187

errno = ioctl_errno;

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

errno = old_errno;

2190

return ioctl_errno;

2191

}

2192

} else if(debug){

2193

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

2194

interface);

2195

}

2196

2197

/* Sleep checking until interface is running.

2198

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

2199

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

2200

if(interface_is_running(interface)){

2201

break;

2202

}

2203

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

ret = nanosleep(&sleeptime, NULL);

2205

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

2206

perror_plus("nanosleep");

2207

}

2208

}

2209

2210

errno = old_errno;

2211

return 0;

2212

}

2213

2214

__attribute__((nonnull, warn_unused_result))

2215

int take_down_interface(const char *const interface){

2216

int old_errno = errno;

2217

struct ifreq network;

2218

unsigned int if_index = if_nametoindex(interface);

2219

if(if_index == 0){

2220

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

2221

errno = old_errno;

2222

return ENXIO;

2223

}

2224

if(interface_is_up(interface)){

2225

int ret_errno = 0;

2226

int ioctl_errno = 0;

2227

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

2228

ret_errno = errno;

2229

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

2230

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

2231

errno = old_errno;

2232

return ret_errno;

2233

}

2234

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

2235

2236

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

2237

if(sd == -1){

2238

ret_errno = errno;

2239

perror_plus("socket");

2240

errno = old_errno;

2241

return ret_errno;

2242

}

2243

2244

if(debug){

2245

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

2246

interface);

2247

}

2248

2249

/* Raise privileges */

2250

ret_errno = raise_privileges();

2251

if(ret_errno != 0){

2252

errno = ret_errno;

2253

perror_plus("Failed to raise privileges");

2254

}

2255

2256

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

2257

ioctl_errno = errno;

2258

2259

/* If raise_privileges() succeeded above */

2260

if(ret_errno == 0){

2261

/* Lower privileges */

2262

ret_errno = lower_privileges();

2263

if(ret_errno != 0){

2264

errno = ret_errno;

2265

perror_plus("Failed to lower privileges");

2266

}

2267

}

2268

2269

/* Close the socket */

2270

int ret = close(sd);

2271

if(ret == -1){

2272

perror_plus("close");

2273

}

2274

2275

if(ret_setflags == -1){

2276

errno = ioctl_errno;

2277

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2278

errno = old_errno;

2279

return ioctl_errno;

2280

}

2281

} else if(debug){

2282

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

2283

interface);

2284

}

2285

2286

errno = old_errno;

2287

return 0;

2288

}

2289

2290

1252

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

2291

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

2296

1253

AvahiSServiceBrowser *sb = NULL;

2297

error_t ret_errno;

1254

int error;

2298

1255

int ret;

2299

1256

intmax_t tmpmax;

2300

1257

char *tmp;

2301

1258

int exitcode = EXIT_SUCCESS;

2302

char *interfaces_to_take_down = NULL;

2303

size_t interfaces_to_take_down_size = 0;

2304

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

2305

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

2306

char *tempdir = NULL;

1259

const char *interface = "";

1260

struct ifreq network;

1261

int sd = -1;

1262

bool take_down_interface = false;

1263

uid_t uid;

1264

gid_t gid;

1265

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

1266

bool tempdir_created = false;

2307

1267

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

1268

const char *seckey = PATHDIR "/" SECKEY;

2309

1269

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

char *interfaces_hooks = NULL;

2312

1270

2313

1271

bool gnutls_initialized = false;

2314

1272

bool gpgme_initialized = false;

2366

1324

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

2367

1325

" Diffie-Hellman key exchange",

2368

1326

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

2374

1327

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

2375

1328

.arg = "STRING",

2376

1329

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

2381

1334

.group = 2 },

2382

1335

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

2383

1336

.arg = "SECONDS",

2384

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

2385

.group = 2 },

2386

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

2387

.arg = "DIR",

2388

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

1337

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

2389

1338

.group = 2 },

2390

1339

/*

2391

1340

* These reproduce what we would get without ARGP_NO_HELP

2410

1359

connect_to = arg;

2411

1360

break;

2412

1361

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

2413

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

2414

arg, (int)',');

2415

if(ret_errno != 0){

2416

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

2417

}

1362

interface = arg;

2418

1363

break;

2419

1364

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

2420

1365

seckey = arg;

2431

1376

}

2432

1377

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

2433

1378

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

1379

case 130: /* --priority */

2438

1380

mc.priority = arg;

2439

1381

break;

2452

1394

argp_error(state, "Bad retry interval");

2453

1395

}

2454

1396

break;

2455

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

2456

hookdir = arg;

2457

break;

2458

1397

/*

2459

1398

* These reproduce what we would get without ARGP_NO_HELP

2460

1399

*/

2466

1405

argp_state_help(state, state->out_stream,

2467

1406

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2468

1407

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

2469

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

1408

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

2470

1409

exit(argp_err_exit_status);

2471

1410

break;

2472

1411

default:

2479

1418

.args_doc = "",

2480

1419

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

2481

1420

" passwords from a Mandos server" };

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

1421

ret = argp_parse(&argp, argc, argv,

1422

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1423

switch(ret){

2485

1424

case 0:

2486

1425

break;

2487

1426

case ENOMEM:

2488

1427

default:

2489

errno = ret_errno;

1428

errno = ret;

2490

1429

perror_plus("argp_parse");

2491

1430

exitcode = EX_OSERR;

2492

1431

goto end;

2495

1434

goto end;

2496

1435

}

2497

1436

}

2498

1437

2499

1438

{

2500

1439

/* Work around Debian bug #633582:

2501

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

2502

2503

/* Re-raise privileges */

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2507

perror_plus("Failed to raise privileges");

2508

} else {

2509

struct stat st;

2510

2511

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

2512

int seckey_fd = open(seckey, O_RDONLY);

2513

if(seckey_fd == -1){

2514

perror_plus("open");

2515

} else {

2516

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

2517

if(ret == -1){

2518

perror_plus("fstat");

2519

} else {

2520

if(S_ISREG(st.st_mode)

2521

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

2522

ret = fchown(seckey_fd, uid, gid);

2523

if(ret == -1){

2524

perror_plus("fchown");

2525

}

2526

}

2527

}

2528

close(seckey_fd);

2529

}

2530

}

2531

2532

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

2533

int pubkey_fd = open(pubkey, O_RDONLY);

2534

if(pubkey_fd == -1){

2535

perror_plus("open");

2536

} else {

2537

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

2538

if(ret == -1){

2539

perror_plus("fstat");

2540

} else {

2541

if(S_ISREG(st.st_mode)

2542

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

2543

ret = fchown(pubkey_fd, uid, gid);

2544

if(ret == -1){

2545

perror_plus("fchown");

2546

}

2547

}

2548

}

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

2575

/* Lower privileges */

2576

ret = lower_privileges();

2577

if(ret != 0){

2578

errno = ret;

2579

perror_plus("Failed to lower privileges");

2580

}

2581

}

2582

}

2583

2584

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

2585

{

2586

char *interface = NULL;

2587

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

2588

interface))){

2589

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

2590

and if_nametoindex(interface) == 0){

2591

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

2592

fprintf_plus(stderr, "Not using nonexisting interface"

2593

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

2594

}

2595

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

2596

interface = NULL;

2597

}

2598

}

2599

}

2600

2601

/* Run network hooks */

2602

{

2603

if(mc.interfaces != NULL){

2604

interfaces_hooks = malloc(mc.interfaces_size);

2605

if(interfaces_hooks == NULL){

2606

perror_plus("malloc");

2607

goto end;

2608

}

2609

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

2610

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

2611

}

2612

run_network_hooks("start", interfaces_hooks != NULL ?

2613

interfaces_hooks : "", delay);

1440

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

1441

struct stat st;

1442

1443

/* Re-raise priviliges */

1444

errno = 0;

1445

ret = seteuid(0);

1446

if(ret == -1){

1447

perror_plus("seteuid");

1448

}

1449

1450

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

1451

int seckey_fd = open(seckey, O_RDONLY);

1452

if(seckey_fd == -1){

1453

perror_plus("open");

1454

} else {

1455

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

1456

if(ret == -1){

1457

perror_plus("fstat");

1458

} else {

1459

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1460

ret = fchown(seckey_fd, uid, gid);

1461

if(ret == -1){

1462

perror_plus("fchown");

1463

}

1464

}

1465

}

1466

TEMP_FAILURE_RETRY(close(seckey_fd));

1467

}

1468

}

1469

1470

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

1471

int pubkey_fd = open(pubkey, O_RDONLY);

1472

if(pubkey_fd == -1){

1473

perror_plus("open");

1474

} else {

1475

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

1476

if(ret == -1){

1477

perror_plus("fstat");

1478

} else {

1479

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1480

ret = fchown(pubkey_fd, uid, gid);

1481

if(ret == -1){

1482

perror_plus("fchown");

1483

}

1484

}

1485

}

1486

TEMP_FAILURE_RETRY(close(pubkey_fd));

1487

}

1488

}

1489

1490

/* Lower privileges */

1491

errno = 0;

1492

ret = seteuid(uid);

1493

if(ret == -1){

1494

perror_plus("seteuid");

1495

}

2614

1496

}

2615

1497

2616

1498

if(not debug){

2617

1499

avahi_set_log_function(empty_log);

2618

1500

}

1501

1502

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

1503

struct dirent **direntries;

1504

ret = scandir(sys_class_net, &direntries, good_interface,

1505

alphasort);

1506

if(ret >= 1){

1507

/* Pick the first good interface */

1508

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

1509

if(debug){

1510

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

1511

}

1512

if(interface == NULL){

1513

perror_plus("malloc");

1514

free(direntries);

1515

exitcode = EXIT_FAILURE;

1516

goto end;

1517

}

1518

free(direntries);

1519

} else {

1520

free(direntries);

1521

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

1522

exitcode = EXIT_FAILURE;

1523

goto end;

1524

}

1525

}

2619

1526

2620

1527

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

2621

1528

from the signal handler */

2622

1529

/* Initialize the pseudo-RNG for Avahi */

2623

1530

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

2624

simple_poll = avahi_simple_poll_new();

2625

if(simple_poll == NULL){

2626

fprintf_plus(stderr,

2627

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

1531

mc.simple_poll = avahi_simple_poll_new();

1532

if(mc.simple_poll == NULL){

1533

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

2628

1534

exitcode = EX_UNAVAILABLE;

2629

1535

goto end;

2630

1536

}

2692

1598

}

2693

1599

}

2694

1600

2695

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

2696

if(mc.interfaces == NULL){

2697

struct dirent **direntries = NULL;

2698

/* Look for any good interfaces */

2699

ret = scandir(sys_class_net, &direntries, good_interface,

2700

alphasort);

2701

if(ret >= 1){

2702

/* Add all found interfaces to interfaces list */

2703

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

2704

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

2705

direntries[i]->d_name);

2706

if(ret_errno != 0){

2707

errno = ret_errno;

2708

perror_plus("argz_add");

2709

free(direntries[i]);

2710

continue;

2711

}

2712

if(debug){

2713

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

2714

direntries[i]->d_name);

2715

}

2716

free(direntries[i]);

2717

}

2718

free(direntries);

1601

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

1602

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

1603

if_index = (AvahiIfIndex) if_nametoindex(interface);

1604

if(if_index == 0){

1605

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

1606

exitcode = EX_UNAVAILABLE;

1607

goto end;

1608

}

1609

1610

if(quit_now){

1611

goto end;

1612

}

1613

1614

/* Re-raise priviliges */

1615

errno = 0;

1616

ret = seteuid(0);

1617

if(ret == -1){

1618

perror_plus("seteuid");

1619

}

1620

1621

#ifdef __linux__

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

ret = klogctl(8, NULL, 5);

1625

bool restore_loglevel = true;

1626

if(ret == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

1629

}

1630

#endif /* __linux__ */

1631

1632

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1633

if(sd < 0){

1634

perror_plus("socket");

1635

exitcode = EX_OSERR;

1636

#ifdef __linux__

1637

if(restore_loglevel){

1638

ret = klogctl(7, NULL, 0);

1639

if(ret == -1){

1640

perror_plus("klogctl");

1641

}

1642

}

1643

#endif /* __linux__ */

1644

/* Lower privileges */

1645

errno = 0;

1646

ret = seteuid(uid);

1647

if(ret == -1){

1648

perror_plus("seteuid");

1649

}

1650

goto end;

1651

}

1652

strcpy(network.ifr_name, interface);

1653

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

1654

if(ret == -1){

1655

perror_plus("ioctl SIOCGIFFLAGS");

1656

#ifdef __linux__

1657

if(restore_loglevel){

1658

ret = klogctl(7, NULL, 0);

1659

if(ret == -1){

1660

perror_plus("klogctl");

1661

}

1662

}

1663

#endif /* __linux__ */

1664

exitcode = EX_OSERR;

1665

/* Lower privileges */

1666

errno = 0;

1667

ret = seteuid(uid);

1668

if(ret == -1){

1669

perror_plus("seteuid");

1670

}

1671

goto end;

1672

}

1673

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

1674

network.ifr_flags |= IFF_UP;

1675

take_down_interface = true;

1676

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

1677

if(ret == -1){

1678

take_down_interface = false;

1679

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1680

exitcode = EX_OSERR;

1681

#ifdef __linux__

1682

if(restore_loglevel){

1683

ret = klogctl(7, NULL, 0);

1684

if(ret == -1){

1685

perror_plus("klogctl");

1686

}

1687

}

1688

#endif /* __linux__ */

1689

/* Lower privileges */

1690

errno = 0;

1691

ret = seteuid(uid);

1692

if(ret == -1){

1693

perror_plus("seteuid");

1694

}

1695

goto end;

1696

}

1697

}

1698

/* Sleep checking until interface is running.

1699

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

1700

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

1701

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

1702

if(ret == -1){

1703

perror_plus("ioctl SIOCGIFFLAGS");

1704

} else if(network.ifr_flags & IFF_RUNNING){

1705

break;

1706

}

1707

struct timespec sleeptime = { .tv_nsec = 250000000 };

1708

ret = nanosleep(&sleeptime, NULL);

1709

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

1710

perror_plus("nanosleep");

1711

}

1712

}

1713

if(not take_down_interface){

1714

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

1715

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

1716

if(ret == -1){

1717

perror_plus("close");

1718

}

1719

}

1720

#ifdef __linux__

1721

if(restore_loglevel){

1722

/* Restores kernel loglevel to default */

1723

ret = klogctl(7, NULL, 0);

1724

if(ret == -1){

1725

perror_plus("klogctl");

1726

}

1727

}

1728

#endif /* __linux__ */

1729

/* Lower privileges */

1730

errno = 0;

1731

if(take_down_interface){

1732

/* Lower privileges */

1733

ret = seteuid(uid);

1734

if(ret == -1){

1735

perror_plus("seteuid");

1736

}

2719

1737

} else {

2720

if(ret == 0){

2721

free(direntries);

2722

}

2723

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

2724

exitcode = EXIT_FAILURE;

2725

goto end;

2726

}

2727

}

2728

2729

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

2730

{

2731

char *interface = NULL;

2732

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

2733

interface))){

2734

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

2735

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

2736

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

2737

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

2738

interface);

2739

interface = NULL;

2740

while((interface = argz_next(mc.interfaces,

2741

mc.interfaces_size, interface))){

2742

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

2743

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

2744

interface);

2745

interface = NULL;

2746

}

2747

}

2748

break;

2749

}

2750

bool interface_was_up = interface_is_up(interface);

2751

errno = bring_up_interface(interface, delay);

2752

if(not interface_was_up){

2753

if(errno != 0){

2754

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

2755

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

2756

} else {

2757

errno = argz_add(&interfaces_to_take_down,

2758

&interfaces_to_take_down_size,

2759

interface);

2760

if(errno != 0){

2761

perror_plus("argz_add");

2762

}

2763

}

2764

}

2765

}

2766

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

2767

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

2768

}

2769

}

2770

2771

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

2772

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

2773

if(debug){

2774

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

2775

mc.interfaces);

2776

}

2777

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

1738

/* Lower privileges permanently */

1739

ret = setuid(uid);

1740

if(ret == -1){

1741

perror_plus("setuid");

1742

}

1743

}

2778

1744

}

2779

1745

2780

1746

if(quit_now){

2781

1747

goto end;

2782

1748

}

2783

1749

2784

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

1750

ret = init_gnutls_global(pubkey, seckey);

2785

1751

if(ret == -1){

2786

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

1752

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

2787

1753

exitcode = EX_UNAVAILABLE;

2788

1754

goto end;

2789

1755

} else {

2794

1760

goto end;

2795

1761

}

2796

1762

2797

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

2798

tempdir = mkdtemp(run_tempdir);

2799

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

2800

if(debug){

2801

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

2802

run_tempdir, old_tempdir);

2803

}

2804

tempdir = mkdtemp(old_tempdir);

2805

}

2806

if(tempdir == NULL){

1763

if(mkdtemp(tempdir) == NULL){

2807

1764

perror_plus("mkdtemp");

2808

1765

goto end;

2809

1766

}

1767

tempdir_created = true;

2810

1768

2811

1769

if(quit_now){

2812

1770

goto end;

2813

1771

}

2814

1772

2815

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

2816

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

1773

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

1774

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

2817

1775

exitcode = EX_UNAVAILABLE;

2818

1776

goto end;

2819

1777

} else {

2828

1786

/* Connect directly, do not use Zeroconf */

2829

1787

/* (Mainly meant for debugging) */

2830

1788

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

2831

2832

1789

if(address == NULL){

2833

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

1790

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

2834

1791

exitcode = EX_USAGE;

2835

1792

goto end;

2836

1793

}

2839

1796

goto end;

2840

1797

}

2841

1798

2842

in_port_t port;

1799

uint16_t port;

2843

1800

errno = 0;

2844

1801

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

2845

1802

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

2846

or tmpmax != (in_port_t)tmpmax){

2847

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

1803

or tmpmax != (uint16_t)tmpmax){

1804

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

2848

1805

exitcode = EX_USAGE;

2849

1806

goto end;

2850

1807

}

2851

1808

2852

1809

if(quit_now){

2853

1810

goto end;

2854

1811

}

2855

1812

2856

port = (in_port_t)tmpmax;

1813

port = (uint16_t)tmpmax;

2857

1814

*address = '\0';

2858

1815

/* Colon in address indicates IPv6 */

2859

1816

int af;

2875

1832

}

2876

1833

2877

1834

while(not quit_now){

2878

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

2879

&mc);

1835

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

2880

1836

if(quit_now or ret == 0){

2881

1837

break;

2882

1838

}

2883

1839

if(debug){

2884

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

2885

(int)retry_interval);

1840

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

1841

(int)retry_interval);

2886

1842

}

2887

sleep((unsigned int)retry_interval);

1843

sleep((int)retry_interval);

2888

1844

}

2889

1845

2890

if(not quit_now){

1846

if (not quit_now){

2891

1847

exitcode = EXIT_SUCCESS;

2892

1848

}

2893

1849

2894

1850

goto end;

2895

1851

}

2896

1852

2908

1864

config.publish_domain = 0;

2909

1865

2910

1866

/* Allocate a new server */

2911

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2912

&config, NULL, NULL, &ret);

1867

mc.server = avahi_server_new(avahi_simple_poll_get

1868

(mc.simple_poll), &config, NULL,

1869

NULL, &error);

2913

1870

2914

1871

/* Free the Avahi configuration data */

2915

1872

avahi_server_config_free(&config);

2917

1874

2918

1875

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

2919

1876

if(mc.server == NULL){

2920

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

2921

avahi_strerror(ret));

1877

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

1878

avahi_strerror(error));

2922

1879

exitcode = EX_UNAVAILABLE;

2923

1880

goto end;

2924

1881

}

2930

1887

/* Create the Avahi service browser */

2931

1888

sb = avahi_s_service_browser_new(mc.server, if_index,

2932

1889

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2933

NULL, 0, browse_callback,

2934

(void *)&mc);

1890

NULL, 0, browse_callback, NULL);

2935

1891

if(sb == NULL){

2936

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

2937

avahi_strerror(avahi_server_errno(mc.server)));

1892

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

1893

avahi_strerror(avahi_server_errno(mc.server)));

2938

1894

exitcode = EX_UNAVAILABLE;

2939

1895

goto end;

2940

1896

}

2946

1902

/* Run the main loop */

2947

1903

2948

1904

if(debug){

2949

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

1905

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

2950

1906

}

2951

2952

ret = avahi_loop_with_timeout(simple_poll,

2953

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

1907

1908

ret = avahi_loop_with_timeout(mc.simple_poll,

1909

(int)(retry_interval * 1000));

2954

1910

if(debug){

2955

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

2956

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

1911

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

1912

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

2957

1913

}

2958

1914

2959

1915

end:

2960

1916

2961

1917

if(debug){

2962

if(signal_received){

2963

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

2964

argv[0], signal_received,

2965

strsignal(signal_received));

2966

} else {

2967

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

2968

}

1918

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

2969

1919

}

2970

1920

2971

1921

/* Cleanup things */

2972

free(mc.interfaces);

2973

2974

1922

if(sb != NULL)

2975

1923

avahi_s_service_browser_free(sb);

2976

1924

2977

1925

if(mc.server != NULL)

2978

1926

avahi_server_free(mc.server);

2979

1927

2980

if(simple_poll != NULL)

2981

avahi_simple_poll_free(simple_poll);

1928

if(mc.simple_poll != NULL)

1929

avahi_simple_poll_free(mc.simple_poll);

2982

1930

2983

1931

if(gnutls_initialized){

2984

1932

gnutls_certificate_free_credentials(mc.cred);

1933

gnutls_global_deinit();

2985

1934

gnutls_dh_params_deinit(mc.dh_params);

2986

1935

}

2987

1936

2988

1937

if(gpgme_initialized){

2989

1938

gpgme_release(mc.ctx);

2990

1939

}

2991

1940

2992

1941

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

2993

1942

has seen */

2994

1943

if(mc.current_server != NULL){

2995

1944

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

2996

1945

while(mc.current_server != NULL){

2997

1946

server *next = mc.current_server->next;

2998

#ifdef __GNUC__

2999

#pragma GCC diagnostic push

3000

#pragma GCC diagnostic ignored "-Wcast-qual"

3001

#endif

3002

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

3003

#ifdef __GNUC__

3004

#pragma GCC diagnostic pop

3005

#endif

3006

1947

free(mc.current_server);

3007

1948

mc.current_server = next;

3008

1949

}

3009

1950

}

3010

1951

3011

/* Re-raise privileges */

3012

{

3013

ret = raise_privileges();

3014

if(ret != 0){

3015

errno = ret;

3016

perror_plus("Failed to raise privileges");

3017

} else {

3018

3019

/* Run network hooks */

3020

run_network_hooks("stop", interfaces_hooks != NULL ?

3021

interfaces_hooks : "", delay);

3022

3023

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

3024

{

3025

char *interface = NULL;

3026

while((interface = argz_next(interfaces_to_take_down,

3027

interfaces_to_take_down_size,

3028

interface))){

3029

ret = take_down_interface(interface);

3030

if(ret != 0){

3031

errno = ret;

3032

perror_plus("Failed to take down interface");

3033

}

3034

}

3035

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

3036

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

3037

" down\n");

3038

}

3039

}

1952

/* Take down the network interface */

1953

if(take_down_interface){

1954

/* Re-raise priviliges */

1955

errno = 0;

1956

ret = seteuid(0);

1957

if(ret == -1){

1958

perror_plus("seteuid");

3040

1959

}

3041

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

3045

perror_plus("Failed to lower privileges permanently");

1960

if(geteuid() == 0){

1961

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

1962

if(ret == -1){

1963

perror_plus("ioctl SIOCGIFFLAGS");

1964

} else if(network.ifr_flags & IFF_UP) {

1965

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

1966

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

1967

if(ret == -1){

1968

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1969

}

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("close");

1974

}

1975

/* Lower privileges permanently */

1976

errno = 0;

1977

ret = setuid(uid);

1978

if(ret == -1){

1979

perror_plus("setuid");

1980

}

3046

1981

}

3047

1982

}

3048

1983

3049

free(interfaces_to_take_down);

3050

free(interfaces_hooks);

3051

3052

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

3053

uintmax_t level){

1984

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

1985

if(tempdir_created){

3054

1986

struct dirent **direntries = NULL;

3055

int dret;

3056

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

3057

O_RDONLY

3058

| O_NOFOLLOW

3059

| O_DIRECTORY

3060

| O_PATH));

3061

if(dir_fd == -1){

3062

perror_plus("open");

3063

}

3064

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

3065

notdotentries, alphasort);

3066

if(numentries >= 0){

1987

struct dirent *direntry = NULL;

1988

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

1989

alphasort);

1990

if (numentries > 0){

3067

1991

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

3068

if(debug){

3069

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

3070

dirname, direntries[i]->d_name);

3071

}

3072

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

3073

if(dret == -1){

3074

if(errno == EISDIR){

3075

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

3076

AT_REMOVEDIR);

3077

}

3078

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

3079

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

3080

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

3081

/* Recurse only in this special case */

3082

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

3083

dret = 0;

3084

}

3085

if(dret == -1){

3086

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

3087

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

3088

}

3089

}

3090

free(direntries[i]);

3091

}

3092

3093

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

3094

free(direntries);

3095

if(numentries == -1){

3096

perror_plus("scandirat");

3097

}

3098

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3099

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

3100

perror_plus("rmdir");

3101

}

3102

} else {

3103

perror_plus("scandirat");

3104

}

3105

close(dir_fd);

3106

}

3107

3108

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

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

1992

direntry = direntries[i];

1993

char *fullname = NULL;

1994

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

1995

direntry->d_name);

1996

if(ret < 0){

1997

perror_plus("asprintf");

1998

continue;

1999

}

2000

ret = remove(fullname);

2001

if(ret == -1){

2002

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

2003

strerror(errno));

2004

}

2005

free(fullname);

2006

}

2007

}

2008

2009

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

2010

free(direntries);

2011

if (numentries == -1){

2012

perror_plus("scandir");

2013

}

2014

ret = rmdir(tempdir);

2015

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

2016

perror_plus("rmdir");

2017

}

3111

2018

}

3112

2019

3113

2020

if(quit_now){