main/tcptls.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2007 - 2008, Digium, Inc.
   5  *
   6  * Luigi Rizzo (TCP and TLS server code)
   7  * Brett Bryant <brettbryant@gmail.com> (updated for client support)
   8  *
   9  * See http://www.asterisk.org for more information about
  10  * the Asterisk project. Please do not directly contact
  11  * any of the maintainers of this project for assistance;
  12  * the project provides a web site, mailing lists and IRC
  13  * channels for your use.
  14  *
  15  * This program is free software, distributed under the terms of
  16  * the GNU General Public License Version 2. See the LICENSE file
  17  * at the top of the source tree.
  18  */
  19
  20 /*!
  21  * \file
  22  * \brief Code to support TCP and TLS server/client
  23  *
  24  * \author Luigi Rizzo
  25  * \author Brett Bryant <brettbryant@gmail.com>
  26  */
  27
  28 #include "asterisk.h"
  29
  30 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  31
  32 #ifdef HAVE_FCNTL_H
  33 #include <fcntl.h>
  34 #endif
  35
  36 #include <sys/signal.h>
  37
  38 #include "asterisk/compat.h"
  39 #include "asterisk/tcptls.h"
  40 #include "asterisk/http.h"
  41 #include "asterisk/utils.h"
  42 #include "asterisk/strings.h"
  43 #include "asterisk/options.h"
  44 #include "asterisk/manager.h"
  45 #include "asterisk/astobj2.h"
  46
  47 /*! \brief
  48  * replacement read/write functions for SSL support.
  49  * We use wrappers rather than SSL_read/SSL_write directly so
  50  * we can put in some debugging.
  51  */
  52
  53 #ifdef DO_SSL
  54 static HOOK_T ssl_read(void *cookie, char *buf, LEN_T len)
  55 {
  56         int i = SSL_read(cookie, buf, len-1);
  57 #if 0
  58         if (i >= 0)
  59                 buf[i] = '\0';
  60         ast_verb(0, "ssl read size %d returns %d <%s>\n", (int)len, i, buf);
  61 #endif
  62         return i;
  63 }
  64
  65 static HOOK_T ssl_write(void *cookie, const char *buf, LEN_T len)
  66 {
  67 #if 0
  68         char *s = alloca(len+1);
  69         strncpy(s, buf, len);
  70         s[len] = '\0';
  71         ast_verb(0, "ssl write size %d <%s>\n", (int)len, s);
  72 #endif
  73         return SSL_write(cookie, buf, len);
  74 }
  75
  76 static int ssl_close(void *cookie)
  77 {
  78         close(SSL_get_fd(cookie));
  79         SSL_shutdown(cookie);
  80         SSL_free(cookie);
  81         return 0;
  82 }
  83 #endif  /* DO_SSL */
  84
  85 HOOK_T ast_tcptls_server_read(struct ast_tcptls_session_instance *tcptls_session, void *buf, size_t count)
  86 {
  87         if (tcptls_session->fd == -1) {
  88                 ast_log(LOG_ERROR, "server_read called with an fd of -1\n");
  89                 errno = EIO;
  90                 return -1;
  91         }
  92
  93 #ifdef DO_SSL
  94         if (tcptls_session->ssl)
  95                 return ssl_read(tcptls_session->ssl, buf, count);
  96 #endif
  97         return read(tcptls_session->fd, buf, count);
  98 }
  99
 100 HOOK_T ast_tcptls_server_write(struct ast_tcptls_session_instance *tcptls_session, const void *buf, size_t count)
 101 {
 102         if (tcptls_session->fd == -1) {
 103                 ast_log(LOG_ERROR, "server_write called with an fd of -1\n");
 104                 errno = EIO;
 105                 return -1;
 106         }
 107
 108 #ifdef DO_SSL
 109         if (tcptls_session->ssl)
 110                 return ssl_write(tcptls_session->ssl, buf, count);
 111 #endif
 112         return write(tcptls_session->fd, buf, count);
 113 }
 114
 115 static void session_instance_destructor(void *obj)
 116 {
 117         struct ast_tcptls_session_instance *i = obj;
 118         ast_mutex_destroy(&i->lock);
 119 }
 120
 121 /*! \brief
 122 * creates a FILE * from the fd passed by the accept thread.
 123 * This operation is potentially expensive (certificate verification),
 124 * so we do it in the child thread context.
 125 *
 126 * \note must decrement ref count before returning NULL on error
 127 */
 128 static void *handle_tcptls_connection(void *data)
 129 {
 130         struct ast_tcptls_session_instance *tcptls_session = data;
 131 #ifdef DO_SSL
 132         int (*ssl_setup)(SSL *) = (tcptls_session->client) ? SSL_connect : SSL_accept;
 133         int ret;
 134         char err[256];
 135 #endif
 136
 137         /*
 138         * open a FILE * as appropriate.
 139         */
 140         if (!tcptls_session->parent->tls_cfg) {
 141                 tcptls_session->f = fdopen(tcptls_session->fd, "w+");
 142                 setvbuf(tcptls_session->f, NULL, _IONBF, 0);
 143         }
 144 #ifdef DO_SSL
 145         else if ( (tcptls_session->ssl = SSL_new(tcptls_session->parent->tls_cfg->ssl_ctx)) ) {
 146                 SSL_set_fd(tcptls_session->ssl, tcptls_session->fd);
 147                 if ((ret = ssl_setup(tcptls_session->ssl)) <= 0) {
 148                         ast_verb(2, "Problem setting up ssl connection: %s\n", ERR_error_string(ERR_get_error(), err));
 149                 } else {
 150 #if defined(HAVE_FUNOPEN)       /* the BSD interface */
 151                         tcptls_session->f = funopen(tcptls_session->ssl, ssl_read, ssl_write, NULL, ssl_close);
 152
 153 #elif defined(HAVE_FOPENCOOKIE) /* the glibc/linux interface */
 154                         static const cookie_io_functions_t cookie_funcs = {
 155                                 ssl_read, ssl_write, NULL, ssl_close
 156                         };
 157                         tcptls_session->f = fopencookie(tcptls_session->ssl, "w+", cookie_funcs);
 158 #else
 159                         /* could add other methods here */
 160                         ast_debug(2, "no tcptls_session->f methods attempted!");
 161 #endif
 162                         if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
 163                                 || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
 164                                 X509 *peer;
 165                                 long res;
 166                                 peer = SSL_get_peer_certificate(tcptls_session->ssl);
 167                                 if (!peer)
 168                                         ast_log(LOG_WARNING, "No peer SSL certificate\n");
 169                                 res = SSL_get_verify_result(tcptls_session->ssl);
 170                                 if (res != X509_V_OK)
 171                                         ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
 172                                 if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
 173                                         ASN1_STRING *str;
 174                                         unsigned char *str2;
 175                                         X509_NAME *name = X509_get_subject_name(peer);
 176                                         int pos = -1;
 177                                         int found = 0;
 178
 179                                         for (;;) {
 180                                                 /* Walk the certificate to check all available "Common Name" */
 181                                                 /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
 182                                                 pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
 183                                                 if (pos < 0)
 184                                                         break;
 185                                                 str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
 186                                                 ASN1_STRING_to_UTF8(&str2, str);
 187                                                 if (str2) {
 188                                                         if (!strcasecmp(tcptls_session->parent->hostname, (char *) str2))
 189                                                                 found = 1;
 190                                                         ast_debug(3, "SSL Common Name compare s1='%s' s2='%s'\n", tcptls_session->parent->hostname, str2);
 191                                                         OPENSSL_free(str2);
 192                                                 }
 193                                                 if (found)
 194                                                         break;
 195                                         }
 196                                         if (!found) {
 197                                                 ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
 198                                                 if (peer)
 199                                                         X509_free(peer);
 200                                                 close(tcptls_session->fd);
 201                                                 fclose(tcptls_session->f);
 202                                                 ao2_ref(tcptls_session, -1);
 203                                                 return NULL;
 204                                         }
 205                                 }
 206                                 if (peer)
 207                                         X509_free(peer);
 208                         }
 209                 }
 210                 if (!tcptls_session->f) /* no success opening descriptor stacking */
 211                         SSL_free(tcptls_session->ssl);
 212    }
 213 #endif /* DO_SSL */
 214
 215         if (!tcptls_session->f) {
 216                 close(tcptls_session->fd);
 217                 ast_log(LOG_WARNING, "FILE * open failed!\n");
 218 #ifndef DO_SSL
 219                 if (tcptls_session->parent->tls_cfg) {
 220                         ast_log(LOG_WARNING, "Attempted a TLS connection without openssl support.  This will not work!\n");
 221                 }
 222 #endif
 223                 ao2_ref(tcptls_session, -1);
 224                 return NULL;
 225         }
 226
 227         if (tcptls_session && tcptls_session->parent->worker_fn)
 228                 return tcptls_session->parent->worker_fn(tcptls_session);
 229         else
 230                 return tcptls_session;
 231 }
 232
 233 void *ast_tcptls_server_root(void *data)
 234 {
 235         struct ast_tcptls_session_args *desc = data;
 236         int fd;
 237         struct sockaddr_in sin;
 238         socklen_t sinlen;
 239         struct ast_tcptls_session_instance *tcptls_session;
 240         pthread_t launched;
 241
 242         for (;;) {
 243                 int i, flags;
 244
 245                 if (desc->periodic_fn)
 246                         desc->periodic_fn(desc);
 247                 i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
 248                 if (i <= 0)
 249                         continue;
 250                 sinlen = sizeof(sin);
 251                 fd = accept(desc->accept_fd, (struct sockaddr *) &sin, &sinlen);
 252                 if (fd < 0) {
 253                         if ((errno != EAGAIN) && (errno != EINTR))
 254                                 ast_log(LOG_WARNING, "Accept failed: %s\n", strerror(errno));
 255                         continue;
 256                 }
 257                 tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
 258                 if (!tcptls_session) {
 259                         ast_log(LOG_WARNING, "No memory for new session: %s\n", strerror(errno));
 260                         close(fd);
 261                         continue;
 262                 }
 263
 264                 ast_mutex_init(&tcptls_session->lock);
 265
 266                 flags = fcntl(fd, F_GETFL);
 267                 fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
 268                 tcptls_session->fd = fd;
 269                 tcptls_session->parent = desc;
 270                 memcpy(&tcptls_session->remote_address, &sin, sizeof(tcptls_session->remote_address));
 271
 272                 tcptls_session->client = 0;
 273
 274                 /* This thread is now the only place that controls the single ref to tcptls_session */
 275                 if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
 276                         ast_log(LOG_WARNING, "Unable to launch helper thread: %s\n", strerror(errno));
 277                         close(tcptls_session->fd);
 278                         ao2_ref(tcptls_session, -1);
 279                 }
 280         }
 281         return NULL;
 282 }
 283
 284 static int __ssl_setup(struct ast_tls_config *cfg, int client)
 285 {
 286 #ifndef DO_SSL
 287         cfg->enabled = 0;
 288         return 0;
 289 #else
 290         if (!cfg->enabled)
 291                 return 0;
 292
 293         SSL_load_error_strings();
 294         SSLeay_add_ssl_algorithms();
 295
 296         if (client) {
 297                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV2_CLIENT)) {
 298                         cfg->ssl_ctx = SSL_CTX_new(SSLv2_client_method());
 299                 } else if (ast_test_flag(&cfg->flags, AST_SSL_SSLV3_CLIENT)) {
 300                         cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());
 301                 } else if (ast_test_flag(&cfg->flags, AST_SSL_TLSV1_CLIENT)) {
 302                         cfg->ssl_ctx = SSL_CTX_new(TLSv1_client_method());
 303                 } else {
 304                         /* SSLv23_client_method() sends SSLv2, this was the original
 305                          * default for ssl clients before the option was given to
 306                          * pick what protocol a client should use.  In order not
 307                          * to break expected behavior it remains the default. */
 308                         cfg->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
 309                 }
 310         } else {
 311                 /* SSLv23_server_method() supports TLSv1, SSLv2, and SSLv3 inbound connections. */
 312                 cfg->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
 313         }
 314
 315         if (!cfg->ssl_ctx) {
 316                 ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
 317                 cfg->enabled = 0;
 318                 return 0;
 319         }
 320         if (!ast_strlen_zero(cfg->certfile)) {
 321                 char *tmpprivate = ast_strlen_zero(cfg->pvtfile) ? cfg->certfile : cfg->pvtfile;
 322                 if (SSL_CTX_use_certificate_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0) {
 323                         if (!client) {
 324                                 /* Clients don't need a certificate, but if its setup we can use it */
 325                                 ast_verb(0, "SSL error loading cert file. <%s>", cfg->certfile);
 326                                 sleep(2);
 327                                 cfg->enabled = 0;
 328                                 return 0;
 329                         }
 330                 }
 331                 if ((SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, tmpprivate, SSL_FILETYPE_PEM) == 0) || (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 )) {
 332                         if (!client) {
 333                                 /* Clients don't need a private key, but if its setup we can use it */
 334                                 ast_verb(0, "SSL error loading private key file. <%s>", tmpprivate);
 335                                 sleep(2);
 336                                 cfg->enabled = 0;
 337                                 return 0;
 338                         }
 339                 }
 340         }
 341         if (!ast_strlen_zero(cfg->cipher)) {
 342                 if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
 343                         if (!client) {
 344                                 ast_verb(0, "SSL cipher error <%s>", cfg->cipher);
 345                                 sleep(2);
 346                                 cfg->enabled = 0;
 347                                 return 0;
 348                         }
 349                 }
 350         }
 351         if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
 352                 if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0)
 353                         ast_verb(0, "SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
 354         }
 355
 356         ast_verb(0, "SSL certificate ok\n");
 357         return 1;
 358 #endif
 359 }
 360
 361 int ast_ssl_setup(struct ast_tls_config *cfg)
 362 {
 363         return __ssl_setup(cfg, 0);
 364 }
 365
 366 struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_instance *tcptls_session)
 367 {
 368         struct ast_tcptls_session_args *desc;
 369         int flags;
 370
 371         if (!(desc = tcptls_session->parent)) {
 372                 goto client_start_error;
 373         }
 374
 375         if (connect(desc->accept_fd, (const struct sockaddr *) &desc->remote_address, sizeof(desc->remote_address))) {
 376                 ast_log(LOG_ERROR, "Unable to connect %s to %s:%d: %s\n",
 377                         desc->name,
 378                         ast_inet_ntoa(desc->remote_address.sin_addr), ntohs(desc->remote_address.sin_port),
 379                         strerror(errno));
 380                 goto client_start_error;
 381         }
 382
 383         flags = fcntl(desc->accept_fd, F_GETFL);
 384         fcntl(desc->accept_fd, F_SETFL, flags & ~O_NONBLOCK);
 385
 386         if (desc->tls_cfg) {
 387                 desc->tls_cfg->enabled = 1;
 388                 __ssl_setup(desc->tls_cfg, 1);
 389         }
 390
 391         return handle_tcptls_connection(tcptls_session);
 392
 393 client_start_error:
 394         close(desc->accept_fd);
 395         desc->accept_fd = -1;
 396         if (tcptls_session) {
 397                 ao2_ref(tcptls_session, -1);
 398         }
 399         return NULL;
 400
 401 }
 402
 403 struct ast_tcptls_session_instance *ast_tcptls_client_create(struct ast_tcptls_session_args *desc)
 404 {
 405         int x = 1;
 406         struct ast_tcptls_session_instance *tcptls_session = NULL;
 407
 408         /* Do nothing if nothing has changed */
 409         if (!memcmp(&desc->old_address, &desc->remote_address, sizeof(desc->old_address))) {
 410                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 411                 return NULL;
 412         }
 413
 414         desc->old_address = desc->remote_address;
 415
 416         if (desc->accept_fd != -1)
 417                 close(desc->accept_fd);
 418
 419         desc->accept_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 420         if (desc->accept_fd < 0) {
 421                 ast_log(LOG_WARNING, "Unable to allocate socket for %s: %s\n",
 422                         desc->name, strerror(errno));
 423                 return NULL;
 424         }
 425
 426         /* if a local address was specified, bind to it so the connection will
 427            originate from the desired address */
 428         if (desc->local_address.sin_family != 0) {
 429                 setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 430                 if (bind(desc->accept_fd, (struct sockaddr *) &desc->local_address, sizeof(desc->local_address))) {
 431                         ast_log(LOG_ERROR, "Unable to bind %s to %s:%d: %s\n",
 432                         desc->name,
 433                                 ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
 434                                 strerror(errno));
 435                         goto error;
 436                 }
 437         }
 438
 439         if (!(tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor)))
 440                 goto error;
 441
 442         ast_mutex_init(&tcptls_session->lock);
 443         tcptls_session->client = 1;
 444         tcptls_session->fd = desc->accept_fd;
 445         tcptls_session->parent = desc;
 446         tcptls_session->parent->worker_fn = NULL;
 447         memcpy(&tcptls_session->remote_address, &desc->remote_address, sizeof(tcptls_session->remote_address));
 448
 449         return tcptls_session;
 450
 451 error:
 452         close(desc->accept_fd);
 453         desc->accept_fd = -1;
 454         if (tcptls_session)
 455                 ao2_ref(tcptls_session, -1);
 456         return NULL;
 457 }
 458
 459 void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 460 {
 461         int flags;
 462         int x = 1;
 463
 464         /* Do nothing if nothing has changed */
 465         if (!memcmp(&desc->old_address, &desc->local_address, sizeof(desc->old_address))) {
 466                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 467                 return;
 468         }
 469
 470         desc->old_address = desc->local_address;
 471
 472         /* Shutdown a running server if there is one */
 473         if (desc->master != AST_PTHREADT_NULL) {
 474                 pthread_cancel(desc->master);
 475                 pthread_kill(desc->master, SIGURG);
 476                 pthread_join(desc->master, NULL);
 477         }
 478
 479         if (desc->accept_fd != -1)
 480                 close(desc->accept_fd);
 481
 482         /* If there's no new server, stop here */
 483         if (desc->local_address.sin_family == 0) {
 484                 ast_debug(2, "Server disabled:  %s\n", desc->name);
 485                 return;
 486         }
 487
 488         desc->accept_fd = socket(AF_INET, SOCK_STREAM, 0);
 489         if (desc->accept_fd < 0) {
 490                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n", desc->name, strerror(errno));
 491                 return;
 492         }
 493
 494         setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 495         if (bind(desc->accept_fd, (struct sockaddr *) &desc->local_address, sizeof(desc->local_address))) {
 496                 ast_log(LOG_ERROR, "Unable to bind %s to %s:%d: %s\n",
 497                         desc->name,
 498                         ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
 499                         strerror(errno));
 500                 goto error;
 501         }
 502         if (listen(desc->accept_fd, 10)) {
 503                 ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
 504                 goto error;
 505         }
 506         flags = fcntl(desc->accept_fd, F_GETFL);
 507         fcntl(desc->accept_fd, F_SETFL, flags | O_NONBLOCK);
 508         if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
 509                 ast_log(LOG_ERROR, "Unable to launch thread for %s on %s:%d: %s\n",
 510                         desc->name,
 511                         ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
 512                         strerror(errno));
 513                 goto error;
 514         }
 515         return;
 516
 517 error:
 518         close(desc->accept_fd);
 519         desc->accept_fd = -1;
 520 }
 521
 522 void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
 523 {
 524         if (desc->master != AST_PTHREADT_NULL) {
 525                 pthread_cancel(desc->master);
 526                 pthread_kill(desc->master, SIGURG);
 527                 pthread_join(desc->master, NULL);
 528         }
 529         if (desc->accept_fd != -1)
 530                 close(desc->accept_fd);
 531         desc->accept_fd = -1;
 532         ast_debug(2, "Stopped server :: %s\n", desc->name);
 533 }
 534
 535 int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_args *tls_desc, const char *varname, const char *value)
 536 {
 537         if (!strcasecmp(varname, "tlsenable") || !strcasecmp(varname, "sslenable")) {
 538                 tls_cfg->enabled = ast_true(value) ? 1 : 0;
 539                 tls_desc->local_address.sin_family = AF_INET;
 540         } else if (!strcasecmp(varname, "tlscertfile") || !strcasecmp(varname, "sslcert") || !strcasecmp(varname, "tlscert")) {
 541                 ast_free(tls_cfg->certfile);
 542                 tls_cfg->certfile = ast_strdup(value);
 543         } else if (!strcasecmp(varname, "tlsprivatekey") || !strcasecmp(varname, "sslprivatekey")) {
 544                 ast_free(tls_cfg->pvtfile);
 545                 tls_cfg->pvtfile = ast_strdup(value);
 546         } else if (!strcasecmp(varname, "tlscipher") || !strcasecmp(varname, "sslcipher")) {
 547                 ast_free(tls_cfg->cipher);
 548                 tls_cfg->cipher = ast_strdup(value);
 549         } else if (!strcasecmp(varname, "tlscafile")) {
 550                 ast_free(tls_cfg->cafile);
 551                 tls_cfg->cafile = ast_strdup(value);
 552         } else if (!strcasecmp(varname, "tlscapath")) {
 553                 ast_free(tls_cfg->capath);
 554                 tls_cfg->capath = ast_strdup(value);
 555         } else if (!strcasecmp(varname, "tlsverifyclient")) {
 556                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_VERIFY_CLIENT);
 557         } else if (!strcasecmp(varname, "tlsdontverifyserver")) {
 558                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DONT_VERIFY_SERVER);
 559         } else if (!strcasecmp(varname, "tlsbindaddr") || !strcasecmp(varname, "sslbindaddr")) {
 560                 if (ast_parse_arg(value, PARSE_INADDR, &tls_desc->local_address))
 561                         ast_log(LOG_WARNING, "Invalid %s '%s'\n", varname, value);
 562         } else if (!strcasecmp(varname, "tlsbindport") || !strcasecmp(varname, "sslbindport")) {
 563                 tls_desc->local_address.sin_port = htons(atoi(value));
 564         } else if (!strcasecmp(varname, "tlsclientmethod") || !strcasecmp(varname, "sslclientmethod")) {
 565                 if (!strcasecmp(value, "tlsv1")) {
 566                         ast_set_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 567                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 568                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 569                 } else if (!strcasecmp(value, "sslv3")) {
 570                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 571                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 572                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 573                 } else if (!strcasecmp(value, "sslv2")) {
 574                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 575                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 576                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 577                 }
 578         } else {
 579                 return -1;
 580         }
 581
 582         return 0;
 583 }