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 <signal.h>
  37 #include <sys/signal.h>
  38
  39 #include "asterisk/compat.h"
  40 #include "asterisk/tcptls.h"
  41 #include "asterisk/http.h"
  42 #include "asterisk/utils.h"
  43 #include "asterisk/strings.h"
  44 #include "asterisk/options.h"
  45 #include "asterisk/manager.h"
  46 #include "asterisk/astobj2.h"
  47
  48 /*! \brief
  49  * replacement read/write functions for SSL support.
  50  * We use wrappers rather than SSL_read/SSL_write directly so
  51  * we can put in some debugging.
  52  */
  53
  54 #ifdef DO_SSL
  55 static HOOK_T ssl_read(void *cookie, char *buf, LEN_T len)
  56 {
  57         int i = SSL_read(cookie, buf, len-1);
  58 #if 0
  59         if (i >= 0)
  60                 buf[i] = '\0';
  61         ast_verb(0, "ssl read size %d returns %d <%s>\n", (int)len, i, buf);
  62 #endif
  63         return i;
  64 }
  65
  66 static HOOK_T ssl_write(void *cookie, const char *buf, LEN_T len)
  67 {
  68 #if 0
  69         char *s = alloca(len+1);
  70         strncpy(s, buf, len);
  71         s[len] = '\0';
  72         ast_verb(0, "ssl write size %d <%s>\n", (int)len, s);
  73 #endif
  74         return SSL_write(cookie, buf, len);
  75 }
  76
  77 static int ssl_close(void *cookie)
  78 {
  79         close(SSL_get_fd(cookie));
  80         SSL_shutdown(cookie);
  81         SSL_free(cookie);
  82         return 0;
  83 }
  84 #endif  /* DO_SSL */
  85
  86 HOOK_T ast_tcptls_server_read(struct ast_tcptls_session_instance *tcptls_session, void *buf, size_t count)
  87 {
  88         if (tcptls_session->fd == -1) {
  89                 ast_log(LOG_ERROR, "server_read called with an fd of -1\n");
  90                 errno = EIO;
  91                 return -1;
  92         }
  93
  94 #ifdef DO_SSL
  95         if (tcptls_session->ssl)
  96                 return ssl_read(tcptls_session->ssl, buf, count);
  97 #endif
  98         return read(tcptls_session->fd, buf, count);
  99 }
 100
 101 HOOK_T ast_tcptls_server_write(struct ast_tcptls_session_instance *tcptls_session, const void *buf, size_t count)
 102 {
 103         if (tcptls_session->fd == -1) {
 104                 ast_log(LOG_ERROR, "server_write called with an fd of -1\n");
 105                 errno = EIO;
 106                 return -1;
 107         }
 108
 109 #ifdef DO_SSL
 110         if (tcptls_session->ssl)
 111                 return ssl_write(tcptls_session->ssl, buf, count);
 112 #endif
 113         return write(tcptls_session->fd, buf, count);
 114 }
 115
 116 static void session_instance_destructor(void *obj)
 117 {
 118         struct ast_tcptls_session_instance *i = obj;
 119         ast_mutex_destroy(&i->lock);
 120 }
 121
 122 /*! \brief
 123 * creates a FILE * from the fd passed by the accept thread.
 124 * This operation is potentially expensive (certificate verification),
 125 * so we do it in the child thread context.
 126 *
 127 * \note must decrement ref count before returning NULL on error
 128 */
 129 static void *handle_tcptls_connection(void *data)
 130 {
 131         struct ast_tcptls_session_instance *tcptls_session = data;
 132 #ifdef DO_SSL
 133         int (*ssl_setup)(SSL *) = (tcptls_session->client) ? SSL_connect : SSL_accept;
 134         int ret;
 135         char err[256];
 136 #endif
 137
 138         /*
 139         * open a FILE * as appropriate.
 140         */
 141         if (!tcptls_session->parent->tls_cfg) {
 142                 if ((tcptls_session->f = fdopen(tcptls_session->fd, "w+"))) {
 143                         if(setvbuf(tcptls_session->f, NULL, _IONBF, 0)) {
 144                                 fclose(tcptls_session->f);
 145                                 tcptls_session->f = NULL;
 146                         }
 147                 }
 148         }
 149 #ifdef DO_SSL
 150         else if ( (tcptls_session->ssl = SSL_new(tcptls_session->parent->tls_cfg->ssl_ctx)) ) {
 151                 SSL_set_fd(tcptls_session->ssl, tcptls_session->fd);
 152                 if ((ret = ssl_setup(tcptls_session->ssl)) <= 0) {
 153                         ast_verb(2, "Problem setting up ssl connection: %s\n", ERR_error_string(ERR_get_error(), err));
 154                 } else {
 155 #if defined(HAVE_FUNOPEN)       /* the BSD interface */
 156                         tcptls_session->f = funopen(tcptls_session->ssl, ssl_read, ssl_write, NULL, ssl_close);
 157
 158 #elif defined(HAVE_FOPENCOOKIE) /* the glibc/linux interface */
 159                         static const cookie_io_functions_t cookie_funcs = {
 160                                 ssl_read, ssl_write, NULL, ssl_close
 161                         };
 162                         tcptls_session->f = fopencookie(tcptls_session->ssl, "w+", cookie_funcs);
 163 #else
 164                         /* could add other methods here */
 165                         ast_debug(2, "no tcptls_session->f methods attempted!");
 166 #endif
 167                         if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
 168                                 || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
 169                                 X509 *peer;
 170                                 long res;
 171                                 peer = SSL_get_peer_certificate(tcptls_session->ssl);
 172                                 if (!peer)
 173                                         ast_log(LOG_WARNING, "No peer SSL certificate\n");
 174                                 res = SSL_get_verify_result(tcptls_session->ssl);
 175                                 if (res != X509_V_OK)
 176                                         ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
 177                                 if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
 178                                         ASN1_STRING *str;
 179                                         unsigned char *str2;
 180                                         X509_NAME *name = X509_get_subject_name(peer);
 181                                         int pos = -1;
 182                                         int found = 0;
 183
 184                                         for (;;) {
 185                                                 /* Walk the certificate to check all available "Common Name" */
 186                                                 /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
 187                                                 pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
 188                                                 if (pos < 0)
 189                                                         break;
 190                                                 str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
 191                                                 ASN1_STRING_to_UTF8(&str2, str);
 192                                                 if (str2) {
 193                                                         if (!strcasecmp(tcptls_session->parent->hostname, (char *) str2))
 194                                                                 found = 1;
 195                                                         ast_debug(3, "SSL Common Name compare s1='%s' s2='%s'\n", tcptls_session->parent->hostname, str2);
 196                                                         OPENSSL_free(str2);
 197                                                 }
 198                                                 if (found)
 199                                                         break;
 200                                         }
 201                                         if (!found) {
 202                                                 ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
 203                                                 if (peer)
 204                                                         X509_free(peer);
 205                                                 close(tcptls_session->fd);
 206                                                 fclose(tcptls_session->f);
 207                                                 ao2_ref(tcptls_session, -1);
 208                                                 return NULL;
 209                                         }
 210                                 }
 211                                 if (peer)
 212                                         X509_free(peer);
 213                         }
 214                 }
 215                 if (!tcptls_session->f) /* no success opening descriptor stacking */
 216                         SSL_free(tcptls_session->ssl);
 217    }
 218 #endif /* DO_SSL */
 219
 220         if (!tcptls_session->f) {
 221                 close(tcptls_session->fd);
 222                 ast_log(LOG_WARNING, "FILE * open failed!\n");
 223 #ifndef DO_SSL
 224                 if (tcptls_session->parent->tls_cfg) {
 225                         ast_log(LOG_WARNING, "Attempted a TLS connection without OpenSSL support.  This will not work!\n");
 226                 }
 227 #endif
 228                 ao2_ref(tcptls_session, -1);
 229                 return NULL;
 230         }
 231
 232         if (tcptls_session && tcptls_session->parent->worker_fn)
 233                 return tcptls_session->parent->worker_fn(tcptls_session);
 234         else
 235                 return tcptls_session;
 236 }
 237
 238 void *ast_tcptls_server_root(void *data)
 239 {
 240         struct ast_tcptls_session_args *desc = data;
 241         int fd;
 242         struct ast_sockaddr addr;
 243         struct ast_tcptls_session_instance *tcptls_session;
 244         pthread_t launched;
 245
 246         for (;;) {
 247                 int i, flags;
 248
 249                 if (desc->periodic_fn)
 250                         desc->periodic_fn(desc);
 251                 i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
 252                 if (i <= 0)
 253                         continue;
 254                 fd = ast_accept(desc->accept_fd, &addr);
 255                 if (fd < 0) {
 256                         if ((errno != EAGAIN) && (errno != EINTR))
 257                                 ast_log(LOG_WARNING, "Accept failed: %s\n", strerror(errno));
 258                         continue;
 259                 }
 260                 tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
 261                 if (!tcptls_session) {
 262                         ast_log(LOG_WARNING, "No memory for new session: %s\n", strerror(errno));
 263                         close(fd);
 264                         continue;
 265                 }
 266
 267                 ast_mutex_init(&tcptls_session->lock);
 268
 269                 flags = fcntl(fd, F_GETFL);
 270                 fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
 271                 tcptls_session->fd = fd;
 272                 tcptls_session->parent = desc;
 273                 ast_sockaddr_copy(&tcptls_session->remote_address, &addr);
 274
 275                 tcptls_session->client = 0;
 276
 277                 /* This thread is now the only place that controls the single ref to tcptls_session */
 278                 if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
 279                         ast_log(LOG_WARNING, "Unable to launch helper thread: %s\n", strerror(errno));
 280                         close(tcptls_session->fd);
 281                         ao2_ref(tcptls_session, -1);
 282                 }
 283         }
 284         return NULL;
 285 }
 286
 287 static int __ssl_setup(struct ast_tls_config *cfg, int client)
 288 {
 289 #ifndef DO_SSL
 290         cfg->enabled = 0;
 291         return 0;
 292 #else
 293         if (!cfg->enabled)
 294                 return 0;
 295
 296         SSL_load_error_strings();
 297         SSLeay_add_ssl_algorithms();
 298
 299         if (client) {
 300 #ifndef OPENSSL_NO_SSL2
 301                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV2_CLIENT)) {
 302                         cfg->ssl_ctx = SSL_CTX_new(SSLv2_client_method());
 303                 } else
 304 #endif
 305                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV3_CLIENT)) {
 306                         cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());
 307                 } else if (ast_test_flag(&cfg->flags, AST_SSL_TLSV1_CLIENT)) {
 308                         cfg->ssl_ctx = SSL_CTX_new(TLSv1_client_method());
 309                 } else {
 310                         /* SSLv23_client_method() sends SSLv2, this was the original
 311                          * default for ssl clients before the option was given to
 312                          * pick what protocol a client should use.  In order not
 313                          * to break expected behavior it remains the default. */
 314                         cfg->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
 315                 }
 316         } else {
 317                 /* SSLv23_server_method() supports TLSv1, SSLv2, and SSLv3 inbound connections. */
 318                 cfg->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
 319         }
 320
 321         if (!cfg->ssl_ctx) {
 322                 ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
 323                 cfg->enabled = 0;
 324                 return 0;
 325         }
 326         if (!ast_strlen_zero(cfg->certfile)) {
 327                 char *tmpprivate = ast_strlen_zero(cfg->pvtfile) ? cfg->certfile : cfg->pvtfile;
 328                 if (SSL_CTX_use_certificate_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0) {
 329                         if (!client) {
 330                                 /* Clients don't need a certificate, but if its setup we can use it */
 331                                 ast_verb(0, "SSL error loading cert file. <%s>", cfg->certfile);
 332                                 sleep(2);
 333                                 cfg->enabled = 0;
 334                                 return 0;
 335                         }
 336                 }
 337                 if ((SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, tmpprivate, SSL_FILETYPE_PEM) == 0) || (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 )) {
 338                         if (!client) {
 339                                 /* Clients don't need a private key, but if its setup we can use it */
 340                                 ast_verb(0, "SSL error loading private key file. <%s>", tmpprivate);
 341                                 sleep(2);
 342                                 cfg->enabled = 0;
 343                                 return 0;
 344                         }
 345                 }
 346         }
 347         if (!ast_strlen_zero(cfg->cipher)) {
 348                 if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
 349                         if (!client) {
 350                                 ast_verb(0, "SSL cipher error <%s>", cfg->cipher);
 351                                 sleep(2);
 352                                 cfg->enabled = 0;
 353                                 return 0;
 354                         }
 355                 }
 356         }
 357         if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
 358                 if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0)
 359                         ast_verb(0, "SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
 360         }
 361
 362         ast_verb(0, "SSL certificate ok\n");
 363         return 1;
 364 #endif
 365 }
 366
 367 int ast_ssl_setup(struct ast_tls_config *cfg)
 368 {
 369         return __ssl_setup(cfg, 0);
 370 }
 371
 372 struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_instance *tcptls_session)
 373 {
 374         struct ast_tcptls_session_args *desc;
 375         int flags;
 376
 377         if (!(desc = tcptls_session->parent)) {
 378                 goto client_start_error;
 379         }
 380
 381         if (ast_connect(desc->accept_fd, &desc->remote_address)) {
 382                 ast_log(LOG_ERROR, "Unable to connect %s to %s: %s\n",
 383                         desc->name,
 384                         ast_sockaddr_stringify(&desc->remote_address),
 385                         strerror(errno));
 386                 goto client_start_error;
 387         }
 388
 389         flags = fcntl(desc->accept_fd, F_GETFL);
 390         fcntl(desc->accept_fd, F_SETFL, flags & ~O_NONBLOCK);
 391
 392         if (desc->tls_cfg) {
 393                 desc->tls_cfg->enabled = 1;
 394                 __ssl_setup(desc->tls_cfg, 1);
 395         }
 396
 397         return handle_tcptls_connection(tcptls_session);
 398
 399 client_start_error:
 400         close(desc->accept_fd);
 401         desc->accept_fd = -1;
 402         if (tcptls_session) {
 403                 ao2_ref(tcptls_session, -1);
 404         }
 405         return NULL;
 406
 407 }
 408
 409 struct ast_tcptls_session_instance *ast_tcptls_client_create(struct ast_tcptls_session_args *desc)
 410 {
 411         int x = 1;
 412         struct ast_tcptls_session_instance *tcptls_session = NULL;
 413
 414         /* Do nothing if nothing has changed */
 415         if (!ast_sockaddr_cmp(&desc->old_address, &desc->remote_address)) {
 416                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 417                 return NULL;
 418         }
 419
 420         /* If we return early, there is no connection */
 421         ast_sockaddr_setnull(&desc->old_address);
 422
 423         if (desc->accept_fd != -1)
 424                 close(desc->accept_fd);
 425
 426         desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->remote_address) ?
 427                                  AF_INET6 : AF_INET, SOCK_STREAM, IPPROTO_TCP);
 428         if (desc->accept_fd < 0) {
 429                 ast_log(LOG_WARNING, "Unable to allocate socket for %s: %s\n",
 430                         desc->name, strerror(errno));
 431                 return NULL;
 432         }
 433
 434         /* if a local address was specified, bind to it so the connection will
 435            originate from the desired address */
 436         if (!ast_sockaddr_isnull(&desc->local_address)) {
 437                 setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 438                 if (ast_bind(desc->accept_fd, &desc->local_address)) {
 439                         ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 440                                 desc->name,
 441                                 ast_sockaddr_stringify(&desc->local_address),
 442                                 strerror(errno));
 443                         goto error;
 444                 }
 445         }
 446
 447         if (!(tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor)))
 448                 goto error;
 449
 450         ast_mutex_init(&tcptls_session->lock);
 451         tcptls_session->client = 1;
 452         tcptls_session->fd = desc->accept_fd;
 453         tcptls_session->parent = desc;
 454         tcptls_session->parent->worker_fn = NULL;
 455         ast_sockaddr_copy(&tcptls_session->remote_address,
 456                           &desc->remote_address);
 457
 458         /* Set current info */
 459         ast_sockaddr_copy(&desc->old_address, &desc->remote_address);
 460         return tcptls_session;
 461
 462 error:
 463         close(desc->accept_fd);
 464         desc->accept_fd = -1;
 465         if (tcptls_session)
 466                 ao2_ref(tcptls_session, -1);
 467         return NULL;
 468 }
 469
 470 void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 471 {
 472         int flags;
 473         int x = 1;
 474
 475         /* Do nothing if nothing has changed */
 476         if (!ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
 477                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 478                 return;
 479         }
 480
 481         /* If we return early, there is no one listening */
 482         ast_sockaddr_setnull(&desc->old_address);
 483
 484         /* Shutdown a running server if there is one */
 485         if (desc->master != AST_PTHREADT_NULL) {
 486                 pthread_cancel(desc->master);
 487                 pthread_kill(desc->master, SIGURG);
 488                 pthread_join(desc->master, NULL);
 489         }
 490
 491         if (desc->accept_fd != -1)
 492                 close(desc->accept_fd);
 493
 494         /* If there's no new server, stop here */
 495         if (ast_sockaddr_isnull(&desc->local_address)) {
 496                 ast_debug(2, "Server disabled:  %s\n", desc->name);
 497                 return;
 498         }
 499
 500         desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->local_address) ?
 501                                  AF_INET6 : AF_INET, SOCK_STREAM, 0);
 502         if (desc->accept_fd < 0) {
 503                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n", desc->name, strerror(errno));
 504                 return;
 505         }
 506
 507         setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 508         if (ast_bind(desc->accept_fd, &desc->local_address)) {
 509                 ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 510                         desc->name,
 511                         ast_sockaddr_stringify(&desc->local_address),
 512                         strerror(errno));
 513                 goto error;
 514         }
 515         if (listen(desc->accept_fd, 10)) {
 516                 ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
 517                 goto error;
 518         }
 519         flags = fcntl(desc->accept_fd, F_GETFL);
 520         fcntl(desc->accept_fd, F_SETFL, flags | O_NONBLOCK);
 521         if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
 522                 ast_log(LOG_ERROR, "Unable to launch thread for %s on %s: %s\n",
 523                         desc->name,
 524                         ast_sockaddr_stringify(&desc->local_address),
 525                         strerror(errno));
 526                 goto error;
 527         }
 528
 529         /* Set current info */
 530         ast_sockaddr_copy(&desc->old_address, &desc->local_address);
 531
 532         return;
 533
 534 error:
 535         close(desc->accept_fd);
 536         desc->accept_fd = -1;
 537 }
 538
 539 void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
 540 {
 541         if (desc->master != AST_PTHREADT_NULL) {
 542                 pthread_cancel(desc->master);
 543                 pthread_kill(desc->master, SIGURG);
 544                 pthread_join(desc->master, NULL);
 545                 desc->master = AST_PTHREADT_NULL;
 546         }
 547         if (desc->accept_fd != -1)
 548                 close(desc->accept_fd);
 549         desc->accept_fd = -1;
 550         ast_debug(2, "Stopped server :: %s\n", desc->name);
 551 }
 552
 553 int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_args *tls_desc, const char *varname, const char *value)
 554 {
 555         if (!strcasecmp(varname, "tlsenable") || !strcasecmp(varname, "sslenable")) {
 556                 tls_cfg->enabled = ast_true(value) ? 1 : 0;
 557         } else if (!strcasecmp(varname, "tlscertfile") || !strcasecmp(varname, "sslcert") || !strcasecmp(varname, "tlscert")) {
 558                 ast_free(tls_cfg->certfile);
 559                 tls_cfg->certfile = ast_strdup(value);
 560         } else if (!strcasecmp(varname, "tlsprivatekey") || !strcasecmp(varname, "sslprivatekey")) {
 561                 ast_free(tls_cfg->pvtfile);
 562                 tls_cfg->pvtfile = ast_strdup(value);
 563         } else if (!strcasecmp(varname, "tlscipher") || !strcasecmp(varname, "sslcipher")) {
 564                 ast_free(tls_cfg->cipher);
 565                 tls_cfg->cipher = ast_strdup(value);
 566         } else if (!strcasecmp(varname, "tlscafile")) {
 567                 ast_free(tls_cfg->cafile);
 568                 tls_cfg->cafile = ast_strdup(value);
 569         } else if (!strcasecmp(varname, "tlscapath") || !strcasecmp(varname, "tlscadir")) {
 570                 ast_free(tls_cfg->capath);
 571                 tls_cfg->capath = ast_strdup(value);
 572         } else if (!strcasecmp(varname, "tlsverifyclient")) {
 573                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_VERIFY_CLIENT);
 574         } else if (!strcasecmp(varname, "tlsdontverifyserver")) {
 575                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DONT_VERIFY_SERVER);
 576         } else if (!strcasecmp(varname, "tlsbindaddr") || !strcasecmp(varname, "sslbindaddr")) {
 577                 if (ast_parse_arg(value, PARSE_ADDR, &tls_desc->local_address))
 578                         ast_log(LOG_WARNING, "Invalid %s '%s'\n", varname, value);
 579         } else if (!strcasecmp(varname, "tlsclientmethod") || !strcasecmp(varname, "sslclientmethod")) {
 580                 if (!strcasecmp(value, "tlsv1")) {
 581                         ast_set_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 582                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 583                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 584                 } else if (!strcasecmp(value, "sslv3")) {
 585                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 586                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 587                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 588                 } else if (!strcasecmp(value, "sslv2")) {
 589                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 590                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 591                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 592                 }
 593         } else {
 594                 return -1;
 595         }
 596
 597         return 0;
 598 }