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 /*** MODULEINFO
  29         <support_level>core</support_level>
  30  ***/
  31
  32 #include "asterisk.h"
  33
  34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  35
  36 #ifdef HAVE_FCNTL_H
  37 #include <fcntl.h>
  38 #endif
  39
  40 #include <signal.h>
  41 #include <sys/signal.h>
  42
  43 #include "asterisk/compat.h"
  44 #include "asterisk/tcptls.h"
  45 #include "asterisk/http.h"
  46 #include "asterisk/utils.h"
  47 #include "asterisk/strings.h"
  48 #include "asterisk/options.h"
  49 #include "asterisk/manager.h"
  50 #include "asterisk/astobj2.h"
  51 #include "asterisk/pbx.h"
  52
  53 /*! ao2 object used for the FILE stream fopencookie()/funopen() cookie. */
  54 struct ast_tcptls_stream {
  55         /*! SSL state if not NULL */
  56         SSL *ssl;
  57         /*!
  58          * \brief Start time from when an I/O sequence must complete
  59          * by struct ast_tcptls_stream.timeout.
  60          *
  61          * \note If struct ast_tcptls_stream.start.tv_sec is zero then
  62          * start time is the current I/O request.
  63          */
  64         struct timeval start;
  65         /*!
  66          * \brief The socket returned by accept().
  67          *
  68          * \note Set to -1 if the stream is closed.
  69          */
  70         int fd;
  71         /*!
  72          * \brief Timeout in ms relative to struct ast_tcptls_stream.start
  73          * to wait for an event on struct ast_tcptls_stream.fd.
  74          *
  75          * \note Set to -1 to disable timeout.
  76          * \note The socket needs to be set to non-blocking for the timeout
  77          * feature to work correctly.
  78          */
  79         int timeout;
  80         /*! TRUE if stream can exclusively wait for fd input. */
  81         int exclusive_input;
  82 };
  83
  84 void ast_tcptls_stream_set_timeout_disable(struct ast_tcptls_stream *stream)
  85 {
  86         ast_assert(stream != NULL);
  87
  88         stream->timeout = -1;
  89 }
  90
  91 void ast_tcptls_stream_set_timeout_inactivity(struct ast_tcptls_stream *stream, int timeout)
  92 {
  93         ast_assert(stream != NULL);
  94
  95         stream->start.tv_sec = 0;
  96         stream->timeout = timeout;
  97 }
  98
  99 void ast_tcptls_stream_set_timeout_sequence(struct ast_tcptls_stream *stream, struct timeval start, int timeout)
 100 {
 101         ast_assert(stream != NULL);
 102
 103         stream->start = start;
 104         stream->timeout = timeout;
 105 }
 106
 107 void ast_tcptls_stream_set_exclusive_input(struct ast_tcptls_stream *stream, int exclusive_input)
 108 {
 109         ast_assert(stream != NULL);
 110
 111         stream->exclusive_input = exclusive_input;
 112 }
 113
 114 /*!
 115  * \internal
 116  * \brief fopencookie()/funopen() stream read function.
 117  *
 118  * \param cookie Stream control data.
 119  * \param buf Where to put read data.
 120  * \param size Size of the buffer.
 121  *
 122  * \retval number of bytes put into buf.
 123  * \retval 0 on end of file.
 124  * \retval -1 on error.
 125  */
 126 static HOOK_T tcptls_stream_read(void *cookie, char *buf, LEN_T size)
 127 {
 128         struct ast_tcptls_stream *stream = cookie;
 129         struct timeval start;
 130         int ms;
 131         int res;
 132
 133         if (!size) {
 134                 /* You asked for no data you got no data. */
 135                 return 0;
 136         }
 137
 138         if (!stream || stream->fd == -1) {
 139                 errno = EBADF;
 140                 return -1;
 141         }
 142
 143         if (stream->start.tv_sec) {
 144                 start = stream->start;
 145         } else {
 146                 start = ast_tvnow();
 147         }
 148
 149 #if defined(DO_SSL)
 150         if (stream->ssl) {
 151                 for (;;) {
 152                         res = SSL_read(stream->ssl, buf, size);
 153                         if (0 < res) {
 154                                 /* We read some payload data. */
 155                                 return res;
 156                         }
 157                         switch (SSL_get_error(stream->ssl, res)) {
 158                         case SSL_ERROR_ZERO_RETURN:
 159                                 /* Report EOF for a shutdown */
 160                                 ast_debug(1, "TLS clean shutdown alert reading data\n");
 161                                 return 0;
 162                         case SSL_ERROR_WANT_READ:
 163                                 if (!stream->exclusive_input) {
 164                                         /* We cannot wait for data now. */
 165                                         errno = EAGAIN;
 166                                         return -1;
 167                                 }
 168                                 while ((ms = ast_remaining_ms(start, stream->timeout))) {
 169                                         res = ast_wait_for_input(stream->fd, ms);
 170                                         if (0 < res) {
 171                                                 /* Socket is ready to be read. */
 172                                                 break;
 173                                         }
 174                                         if (res < 0) {
 175                                                 if (errno == EINTR || errno == EAGAIN) {
 176                                                         /* Try again. */
 177                                                         continue;
 178                                                 }
 179                                                 ast_debug(1, "TLS socket error waiting for read data: %s\n",
 180                                                         strerror(errno));
 181                                                 return -1;
 182                                         }
 183                                 }
 184                                 break;
 185                         case SSL_ERROR_WANT_WRITE:
 186                                 while ((ms = ast_remaining_ms(start, stream->timeout))) {
 187                                         res = ast_wait_for_output(stream->fd, ms);
 188                                         if (0 < res) {
 189                                                 /* Socket is ready to be written. */
 190                                                 break;
 191                                         }
 192                                         if (res < 0) {
 193                                                 if (errno == EINTR || errno == EAGAIN) {
 194                                                         /* Try again. */
 195                                                         continue;
 196                                                 }
 197                                                 ast_debug(1, "TLS socket error waiting for write space: %s\n",
 198                                                         strerror(errno));
 199                                                 return -1;
 200                                         }
 201                                 }
 202                                 break;
 203                         default:
 204                                 /* Report EOF for an undecoded SSL or transport error. */
 205                                 ast_debug(1, "TLS transport or SSL error reading data\n");
 206                                 return 0;
 207                         }
 208                         if (!ms) {
 209                                 /* Report EOF for a timeout */
 210                                 ast_debug(1, "TLS timeout reading data\n");
 211                                 return 0;
 212                         }
 213                 }
 214         }
 215 #endif  /* defined(DO_SSL) */
 216
 217         for (;;) {
 218                 res = read(stream->fd, buf, size);
 219                 if (0 <= res || !stream->exclusive_input) {
 220                         /* Got data or we cannot wait for it. */
 221                         return res;
 222                 }
 223                 if (errno != EINTR && errno != EAGAIN) {
 224                         /* Not a retryable error. */
 225                         ast_debug(1, "TCP socket error reading data: %s\n",
 226                                 strerror(errno));
 227                         return -1;
 228                 }
 229                 ms = ast_remaining_ms(start, stream->timeout);
 230                 if (!ms) {
 231                         /* Report EOF for a timeout */
 232                         ast_debug(1, "TCP timeout reading data\n");
 233                         return 0;
 234                 }
 235                 ast_wait_for_input(stream->fd, ms);
 236         }
 237 }
 238
 239 /*!
 240  * \internal
 241  * \brief fopencookie()/funopen() stream write function.
 242  *
 243  * \param cookie Stream control data.
 244  * \param buf Where to get data to write.
 245  * \param size Size of the buffer.
 246  *
 247  * \retval number of bytes written from buf.
 248  * \retval -1 on error.
 249  */
 250 static HOOK_T tcptls_stream_write(void *cookie, const char *buf, LEN_T size)
 251 {
 252         struct ast_tcptls_stream *stream = cookie;
 253         struct timeval start;
 254         int ms;
 255         int res;
 256         int written;
 257         int remaining;
 258
 259         if (!size) {
 260                 /* You asked to write no data you wrote no data. */
 261                 return 0;
 262         }
 263
 264         if (!stream || stream->fd == -1) {
 265                 errno = EBADF;
 266                 return -1;
 267         }
 268
 269         if (stream->start.tv_sec) {
 270                 start = stream->start;
 271         } else {
 272                 start = ast_tvnow();
 273         }
 274
 275 #if defined(DO_SSL)
 276         if (stream->ssl) {
 277                 written = 0;
 278                 remaining = size;
 279                 for (;;) {
 280                         res = SSL_write(stream->ssl, buf + written, remaining);
 281                         if (res == remaining) {
 282                                 /* Everything was written. */
 283                                 return size;
 284                         }
 285                         if (0 < res) {
 286                                 /* Successfully wrote part of the buffer.  Try to write the rest. */
 287                                 written += res;
 288                                 remaining -= res;
 289                                 continue;
 290                         }
 291                         switch (SSL_get_error(stream->ssl, res)) {
 292                         case SSL_ERROR_ZERO_RETURN:
 293                                 ast_debug(1, "TLS clean shutdown alert writing data\n");
 294                                 if (written) {
 295                                         /* Report partial write. */
 296                                         return written;
 297                                 }
 298                                 errno = EBADF;
 299                                 return -1;
 300                         case SSL_ERROR_WANT_READ:
 301                                 ms = ast_remaining_ms(start, stream->timeout);
 302                                 if (!ms) {
 303                                         /* Report partial write. */
 304                                         ast_debug(1, "TLS timeout writing data (want read)\n");
 305                                         return written;
 306                                 }
 307                                 ast_wait_for_input(stream->fd, ms);
 308                                 break;
 309                         case SSL_ERROR_WANT_WRITE:
 310                                 ms = ast_remaining_ms(start, stream->timeout);
 311                                 if (!ms) {
 312                                         /* Report partial write. */
 313                                         ast_debug(1, "TLS timeout writing data (want write)\n");
 314                                         return written;
 315                                 }
 316                                 ast_wait_for_output(stream->fd, ms);
 317                                 break;
 318                         default:
 319                                 /* Undecoded SSL or transport error. */
 320                                 ast_debug(1, "TLS transport or SSL error writing data\n");
 321                                 if (written) {
 322                                         /* Report partial write. */
 323                                         return written;
 324                                 }
 325                                 errno = EBADF;
 326                                 return -1;
 327                         }
 328                 }
 329         }
 330 #endif  /* defined(DO_SSL) */
 331
 332         written = 0;
 333         remaining = size;
 334         for (;;) {
 335                 res = write(stream->fd, buf + written, remaining);
 336                 if (res == remaining) {
 337                         /* Yay everything was written. */
 338                         return size;
 339                 }
 340                 if (0 < res) {
 341                         /* Successfully wrote part of the buffer.  Try to write the rest. */
 342                         written += res;
 343                         remaining -= res;
 344                         continue;
 345                 }
 346                 if (errno != EINTR && errno != EAGAIN) {
 347                         /* Not a retryable error. */
 348                         ast_debug(1, "TCP socket error writing: %s\n", strerror(errno));
 349                         if (written) {
 350                                 return written;
 351                         }
 352                         return -1;
 353                 }
 354                 ms = ast_remaining_ms(start, stream->timeout);
 355                 if (!ms) {
 356                         /* Report partial write. */
 357                         ast_debug(1, "TCP timeout writing data\n");
 358                         return written;
 359                 }
 360                 ast_wait_for_output(stream->fd, ms);
 361         }
 362 }
 363
 364 /*!
 365  * \internal
 366  * \brief fopencookie()/funopen() stream close function.
 367  *
 368  * \param cookie Stream control data.
 369  *
 370  * \retval 0 on success.
 371  * \retval -1 on error.
 372  */
 373 static int tcptls_stream_close(void *cookie)
 374 {
 375         struct ast_tcptls_stream *stream = cookie;
 376
 377         if (!stream) {
 378                 errno = EBADF;
 379                 return -1;
 380         }
 381
 382         if (stream->fd != -1) {
 383 #if defined(DO_SSL)
 384                 if (stream->ssl) {
 385                         int res;
 386
 387                         /*
 388                          * According to the TLS standard, it is acceptable for an
 389                          * application to only send its shutdown alert and then
 390                          * close the underlying connection without waiting for
 391                          * the peer's response (this way resources can be saved,
 392                          * as the process can already terminate or serve another
 393                          * connection).
 394                          */
 395                         res = SSL_shutdown(stream->ssl);
 396                         if (res < 0) {
 397                                 ast_log(LOG_ERROR, "SSL_shutdown() failed: %d\n",
 398                                         SSL_get_error(stream->ssl, res));
 399                         }
 400
 401                         if (!stream->ssl->server) {
 402                                 /* For client threads, ensure that the error stack is cleared */
 403                                 ERR_remove_state(0);
 404                         }
 405
 406                         SSL_free(stream->ssl);
 407                         stream->ssl = NULL;
 408                 }
 409 #endif  /* defined(DO_SSL) */
 410
 411                 /*
 412                  * Issuing shutdown() is necessary here to avoid a race
 413                  * condition where the last data written may not appear
 414                  * in the TCP stream.  See ASTERISK-23548
 415                  */
 416                 shutdown(stream->fd, SHUT_RDWR);
 417                 if (close(stream->fd)) {
 418                         ast_log(LOG_ERROR, "close() failed: %s\n", strerror(errno));
 419                 }
 420                 stream->fd = -1;
 421         }
 422         ao2_t_ref(stream, -1, "Closed tcptls stream cookie");
 423
 424         return 0;
 425 }
 426
 427 /*!
 428  * \internal
 429  * \brief fopencookie()/funopen() stream destructor function.
 430  *
 431  * \param cookie Stream control data.
 432  *
 433  * \return Nothing
 434  */
 435 static void tcptls_stream_dtor(void *cookie)
 436 {
 437         struct ast_tcptls_stream *stream = cookie;
 438
 439         ast_assert(stream->fd == -1);
 440 }
 441
 442 /*!
 443  * \internal
 444  * \brief fopencookie()/funopen() stream allocation function.
 445  *
 446  * \retval stream_cookie on success.
 447  * \retval NULL on error.
 448  */
 449 static struct ast_tcptls_stream *tcptls_stream_alloc(void)
 450 {
 451         struct ast_tcptls_stream *stream;
 452
 453         stream = ao2_alloc_options(sizeof(*stream), tcptls_stream_dtor,
 454                 AO2_ALLOC_OPT_LOCK_NOLOCK);
 455         if (stream) {
 456                 stream->fd = -1;
 457                 stream->timeout = -1;
 458         }
 459         return stream;
 460 }
 461
 462 /*!
 463  * \internal
 464  * \brief Open a custom FILE stream for tcptls.
 465  *
 466  * \param stream Stream cookie control data.
 467  * \param ssl SSL state if not NULL.
 468  * \param fd Socket file descriptor.
 469  * \param timeout ms to wait for an event on fd. -1 if timeout disabled.
 470  *
 471  * \retval fp on success.
 472  * \retval NULL on error.
 473  */
 474 static FILE *tcptls_stream_fopen(struct ast_tcptls_stream *stream, SSL *ssl, int fd, int timeout)
 475 {
 476         FILE *fp;
 477
 478 #if defined(HAVE_FOPENCOOKIE)   /* the glibc/linux interface */
 479         static const cookie_io_functions_t cookie_funcs = {
 480                 tcptls_stream_read,
 481                 tcptls_stream_write,
 482                 NULL,
 483                 tcptls_stream_close
 484         };
 485 #endif  /* defined(HAVE_FOPENCOOKIE) */
 486
 487         if (fd == -1) {
 488                 /* Socket not open. */
 489                 return NULL;
 490         }
 491
 492         stream->ssl = ssl;
 493         stream->fd = fd;
 494         stream->timeout = timeout;
 495         ao2_t_ref(stream, +1, "Opening tcptls stream cookie");
 496
 497 #if defined(HAVE_FUNOPEN)       /* the BSD interface */
 498         fp = funopen(stream, tcptls_stream_read, tcptls_stream_write, NULL,
 499                 tcptls_stream_close);
 500 #elif defined(HAVE_FOPENCOOKIE) /* the glibc/linux interface */
 501         fp = fopencookie(stream, "w+", cookie_funcs);
 502 #else
 503         /* could add other methods here */
 504         ast_debug(2, "No stream FILE methods attempted!\n");
 505         fp = NULL;
 506 #endif
 507
 508         if (!fp) {
 509                 stream->fd = -1;
 510                 ao2_t_ref(stream, -1, "Failed to open tcptls stream cookie");
 511         }
 512         return fp;
 513 }
 514
 515 HOOK_T ast_tcptls_server_read(struct ast_tcptls_session_instance *tcptls_session, void *buf, size_t count)
 516 {
 517         if (!tcptls_session->stream_cookie || tcptls_session->stream_cookie->fd == -1) {
 518                 ast_log(LOG_ERROR, "TCP/TLS read called on invalid stream.\n");
 519                 errno = EIO;
 520                 return -1;
 521         }
 522
 523         return tcptls_stream_read(tcptls_session->stream_cookie, buf, count);
 524 }
 525
 526 HOOK_T ast_tcptls_server_write(struct ast_tcptls_session_instance *tcptls_session, const void *buf, size_t count)
 527 {
 528         if (!tcptls_session->stream_cookie || tcptls_session->stream_cookie->fd == -1) {
 529                 ast_log(LOG_ERROR, "TCP/TLS write called on invalid stream.\n");
 530                 errno = EIO;
 531                 return -1;
 532         }
 533
 534         return tcptls_stream_write(tcptls_session->stream_cookie, buf, count);
 535 }
 536
 537 static void session_instance_destructor(void *obj)
 538 {
 539         struct ast_tcptls_session_instance *i = obj;
 540
 541         if (i->stream_cookie) {
 542                 ao2_t_ref(i->stream_cookie, -1, "Destroying tcptls session instance");
 543                 i->stream_cookie = NULL;
 544         }
 545         ast_free(i->overflow_buf);
 546 }
 547
 548 /*! \brief
 549 * creates a FILE * from the fd passed by the accept thread.
 550 * This operation is potentially expensive (certificate verification),
 551 * so we do it in the child thread context.
 552 *
 553 * \note must decrement ref count before returning NULL on error
 554 */
 555 static void *handle_tcptls_connection(void *data)
 556 {
 557         struct ast_tcptls_session_instance *tcptls_session = data;
 558 #ifdef DO_SSL
 559         int (*ssl_setup)(SSL *) = (tcptls_session->client) ? SSL_connect : SSL_accept;
 560         int ret;
 561         char err[256];
 562 #endif
 563
 564         /* TCP/TLS connections are associated with external protocols, and
 565          * should not be allowed to execute 'dangerous' functions. This may
 566          * need to be pushed down into the individual protocol handlers, but
 567          * this seems like a good general policy.
 568          */
 569         if (ast_thread_inhibit_escalations()) {
 570                 ast_log(LOG_ERROR, "Failed to inhibit privilege escalations; killing connection\n");
 571                 ast_tcptls_close_session_file(tcptls_session);
 572                 ao2_ref(tcptls_session, -1);
 573                 return NULL;
 574         }
 575
 576         tcptls_session->stream_cookie = tcptls_stream_alloc();
 577         if (!tcptls_session->stream_cookie) {
 578                 ast_tcptls_close_session_file(tcptls_session);
 579                 ao2_ref(tcptls_session, -1);
 580                 return NULL;
 581         }
 582
 583         /*
 584         * open a FILE * as appropriate.
 585         */
 586         if (!tcptls_session->parent->tls_cfg) {
 587                 tcptls_session->f = tcptls_stream_fopen(tcptls_session->stream_cookie, NULL,
 588                         tcptls_session->fd, -1);
 589                 if (tcptls_session->f) {
 590                         if (setvbuf(tcptls_session->f, NULL, _IONBF, 0)) {
 591                                 ast_tcptls_close_session_file(tcptls_session);
 592                         }
 593                 }
 594         }
 595 #ifdef DO_SSL
 596         else if ( (tcptls_session->ssl = SSL_new(tcptls_session->parent->tls_cfg->ssl_ctx)) ) {
 597                 SSL_set_fd(tcptls_session->ssl, tcptls_session->fd);
 598                 if ((ret = ssl_setup(tcptls_session->ssl)) <= 0) {
 599                         ast_log(LOG_ERROR, "Problem setting up ssl connection: %s\n", ERR_error_string(ERR_get_error(), err));
 600                 } else if ((tcptls_session->f = tcptls_stream_fopen(tcptls_session->stream_cookie,
 601                         tcptls_session->ssl, tcptls_session->fd, -1))) {
 602                         if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
 603                                 || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
 604                                 X509 *peer;
 605                                 long res;
 606                                 peer = SSL_get_peer_certificate(tcptls_session->ssl);
 607                                 if (!peer) {
 608                                         ast_log(LOG_ERROR, "No peer SSL certificate to verify\n");
 609                                         ast_tcptls_close_session_file(tcptls_session);
 610                                         ao2_ref(tcptls_session, -1);
 611                                         return NULL;
 612                                 }
 613
 614                                 res = SSL_get_verify_result(tcptls_session->ssl);
 615                                 if (res != X509_V_OK) {
 616                                         ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
 617                                         X509_free(peer);
 618                                         ast_tcptls_close_session_file(tcptls_session);
 619                                         ao2_ref(tcptls_session, -1);
 620                                         return NULL;
 621                                 }
 622                                 if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
 623                                         ASN1_STRING *str;
 624                                         unsigned char *str2;
 625                                         X509_NAME *name = X509_get_subject_name(peer);
 626                                         int pos = -1;
 627                                         int found = 0;
 628
 629                                         for (;;) {
 630                                                 /* Walk the certificate to check all available "Common Name" */
 631                                                 /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
 632                                                 pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
 633                                                 if (pos < 0) {
 634                                                         break;
 635                                                 }
 636                                                 str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
 637                                                 ASN1_STRING_to_UTF8(&str2, str);
 638                                                 if (str2) {
 639                                                         if (!strcasecmp(tcptls_session->parent->hostname, (char *) str2)) {
 640                                                                 found = 1;
 641                                                         }
 642                                                         ast_debug(3, "SSL Common Name compare s1='%s' s2='%s'\n", tcptls_session->parent->hostname, str2);
 643                                                         OPENSSL_free(str2);
 644                                                 }
 645                                                 if (found) {
 646                                                         break;
 647                                                 }
 648                                         }
 649                                         if (!found) {
 650                                                 ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
 651                                                 X509_free(peer);
 652                                                 ast_tcptls_close_session_file(tcptls_session);
 653                                                 ao2_ref(tcptls_session, -1);
 654                                                 return NULL;
 655                                         }
 656                                 }
 657                                 X509_free(peer);
 658                         }
 659                 }
 660                 if (!tcptls_session->f) {       /* no success opening descriptor stacking */
 661                         SSL_free(tcptls_session->ssl);
 662                 }
 663         }
 664 #endif /* DO_SSL */
 665
 666         if (!tcptls_session->f) {
 667                 ast_tcptls_close_session_file(tcptls_session);
 668                 ast_log(LOG_WARNING, "FILE * open failed!\n");
 669 #ifndef DO_SSL
 670                 if (tcptls_session->parent->tls_cfg) {
 671                         ast_log(LOG_ERROR, "Attempted a TLS connection without OpenSSL support. This will not work!\n");
 672                 }
 673 #endif
 674                 ao2_ref(tcptls_session, -1);
 675                 return NULL;
 676         }
 677
 678         if (tcptls_session->parent->worker_fn) {
 679                 return tcptls_session->parent->worker_fn(tcptls_session);
 680         } else {
 681                 return tcptls_session;
 682         }
 683 }
 684
 685 void *ast_tcptls_server_root(void *data)
 686 {
 687         struct ast_tcptls_session_args *desc = data;
 688         int fd;
 689         struct ast_sockaddr addr;
 690         struct ast_tcptls_session_instance *tcptls_session;
 691         pthread_t launched;
 692
 693         for (;;) {
 694                 int i, flags;
 695
 696                 if (desc->periodic_fn) {
 697                         desc->periodic_fn(desc);
 698                 }
 699                 i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
 700                 if (i <= 0) {
 701                         continue;
 702                 }
 703                 fd = ast_accept(desc->accept_fd, &addr);
 704                 if (fd < 0) {
 705                         if ((errno != EAGAIN) && (errno != EINTR)) {
 706                                 ast_log(LOG_ERROR, "Accept failed: %s\n", strerror(errno));
 707                         }
 708                         continue;
 709                 }
 710                 tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
 711                 if (!tcptls_session) {
 712                         ast_log(LOG_WARNING, "No memory for new session: %s\n", strerror(errno));
 713                         if (close(fd)) {
 714                                 ast_log(LOG_ERROR, "close() failed: %s\n", strerror(errno));
 715                         }
 716                         continue;
 717                 }
 718
 719                 tcptls_session->overflow_buf = ast_str_create(128);
 720                 flags = fcntl(fd, F_GETFL);
 721                 fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
 722                 tcptls_session->fd = fd;
 723                 tcptls_session->parent = desc;
 724                 ast_sockaddr_copy(&tcptls_session->remote_address, &addr);
 725
 726                 tcptls_session->client = 0;
 727
 728                 /* This thread is now the only place that controls the single ref to tcptls_session */
 729                 if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
 730                         ast_log(LOG_ERROR, "Unable to launch helper thread: %s\n", strerror(errno));
 731                         ast_tcptls_close_session_file(tcptls_session);
 732                         ao2_ref(tcptls_session, -1);
 733                 }
 734         }
 735         return NULL;
 736 }
 737
 738 static int __ssl_setup(struct ast_tls_config *cfg, int client)
 739 {
 740 #ifndef DO_SSL
 741         cfg->enabled = 0;
 742         return 0;
 743 #else
 744         if (!cfg->enabled) {
 745                 return 0;
 746         }
 747
 748         /* Get rid of an old SSL_CTX since we're about to
 749          * allocate a new one
 750          */
 751         if (cfg->ssl_ctx) {
 752                 SSL_CTX_free(cfg->ssl_ctx);
 753                 cfg->ssl_ctx = NULL;
 754         }
 755
 756         if (client) {
 757 #ifndef OPENSSL_NO_SSL2
 758                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV2_CLIENT)) {
 759                         cfg->ssl_ctx = SSL_CTX_new(SSLv2_client_method());
 760                 } else
 761 #endif
 762                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV3_CLIENT)) {
 763                         cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());
 764                 } else if (ast_test_flag(&cfg->flags, AST_SSL_TLSV1_CLIENT)) {
 765                         cfg->ssl_ctx = SSL_CTX_new(TLSv1_client_method());
 766                 } else {
 767                         /* SSLv23_client_method() sends SSLv2, this was the original
 768                          * default for ssl clients before the option was given to
 769                          * pick what protocol a client should use.  In order not
 770                          * to break expected behavior it remains the default. */
 771                         cfg->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
 772                 }
 773         } else {
 774                 /* SSLv23_server_method() supports TLSv1, SSLv2, and SSLv3 inbound connections. */
 775                 cfg->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
 776         }
 777
 778         if (!cfg->ssl_ctx) {
 779                 ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
 780                 cfg->enabled = 0;
 781                 return 0;
 782         }
 783
 784         SSL_CTX_set_verify(cfg->ssl_ctx,
 785                 ast_test_flag(&cfg->flags, AST_SSL_VERIFY_CLIENT) ? SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT : SSL_VERIFY_NONE,
 786                 NULL);
 787
 788         if (!ast_strlen_zero(cfg->certfile)) {
 789                 char *tmpprivate = ast_strlen_zero(cfg->pvtfile) ? cfg->certfile : cfg->pvtfile;
 790                 if (SSL_CTX_use_certificate_chain_file(cfg->ssl_ctx, cfg->certfile) == 0) {
 791                         if (!client) {
 792                                 /* Clients don't need a certificate, but if its setup we can use it */
 793                                 ast_log(LOG_ERROR, "TLS/SSL error loading cert file. <%s>\n", cfg->certfile);
 794                                 cfg->enabled = 0;
 795                                 SSL_CTX_free(cfg->ssl_ctx);
 796                                 cfg->ssl_ctx = NULL;
 797                                 return 0;
 798                         }
 799                 }
 800                 if ((SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, tmpprivate, SSL_FILETYPE_PEM) == 0) || (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 )) {
 801                         if (!client) {
 802                                 /* Clients don't need a private key, but if its setup we can use it */
 803                                 ast_log(LOG_ERROR, "TLS/SSL error loading private key file. <%s>\n", tmpprivate);
 804                                 cfg->enabled = 0;
 805                                 SSL_CTX_free(cfg->ssl_ctx);
 806                                 cfg->ssl_ctx = NULL;
 807                                 return 0;
 808                         }
 809                 }
 810         }
 811         if (!ast_strlen_zero(cfg->cipher)) {
 812                 if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
 813                         if (!client) {
 814                                 ast_log(LOG_ERROR, "TLS/SSL cipher error <%s>\n", cfg->cipher);
 815                                 cfg->enabled = 0;
 816                                 SSL_CTX_free(cfg->ssl_ctx);
 817                                 cfg->ssl_ctx = NULL;
 818                                 return 0;
 819                         }
 820                 }
 821         }
 822         if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
 823                 if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0) {
 824                         ast_log(LOG_ERROR, "TLS/SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
 825                 }
 826         }
 827
 828         ast_verb(2, "TLS/SSL certificate ok\n");        /* We should log which one that is ok. This message doesn't really make sense in production use */
 829         return 1;
 830 #endif
 831 }
 832
 833 int ast_ssl_setup(struct ast_tls_config *cfg)
 834 {
 835         return __ssl_setup(cfg, 0);
 836 }
 837
 838 void ast_ssl_teardown(struct ast_tls_config *cfg)
 839 {
 840 #ifdef DO_SSL
 841         if (cfg->ssl_ctx) {
 842                 SSL_CTX_free(cfg->ssl_ctx);
 843                 cfg->ssl_ctx = NULL;
 844         }
 845 #endif
 846 }
 847
 848 struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_instance *tcptls_session)
 849 {
 850         struct ast_tcptls_session_args *desc;
 851         int flags;
 852
 853         if (!(desc = tcptls_session->parent)) {
 854                 goto client_start_error;
 855         }
 856
 857         if (ast_connect(desc->accept_fd, &desc->remote_address)) {
 858                 ast_log(LOG_ERROR, "Unable to connect %s to %s: %s\n",
 859                         desc->name,
 860                         ast_sockaddr_stringify(&desc->remote_address),
 861                         strerror(errno));
 862                 goto client_start_error;
 863         }
 864
 865         flags = fcntl(desc->accept_fd, F_GETFL);
 866         fcntl(desc->accept_fd, F_SETFL, flags & ~O_NONBLOCK);
 867
 868         if (desc->tls_cfg) {
 869                 desc->tls_cfg->enabled = 1;
 870                 __ssl_setup(desc->tls_cfg, 1);
 871         }
 872
 873         return handle_tcptls_connection(tcptls_session);
 874
 875 client_start_error:
 876         if (desc) {
 877                 close(desc->accept_fd);
 878                 desc->accept_fd = -1;
 879         }
 880         ao2_ref(tcptls_session, -1);
 881         return NULL;
 882
 883 }
 884
 885 struct ast_tcptls_session_instance *ast_tcptls_client_create(struct ast_tcptls_session_args *desc)
 886 {
 887         int x = 1;
 888         struct ast_tcptls_session_instance *tcptls_session = NULL;
 889
 890         /* Do nothing if nothing has changed */
 891         if (!ast_sockaddr_cmp(&desc->old_address, &desc->remote_address)) {
 892                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 893                 return NULL;
 894         }
 895
 896         /* If we return early, there is no connection */
 897         ast_sockaddr_setnull(&desc->old_address);
 898
 899         if (desc->accept_fd != -1) {
 900                 close(desc->accept_fd);
 901         }
 902
 903         desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->remote_address) ?
 904                                  AF_INET6 : AF_INET, SOCK_STREAM, IPPROTO_TCP);
 905         if (desc->accept_fd < 0) {
 906                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n",
 907                         desc->name, strerror(errno));
 908                 return NULL;
 909         }
 910
 911         /* if a local address was specified, bind to it so the connection will
 912            originate from the desired address */
 913         if (!ast_sockaddr_isnull(&desc->local_address)) {
 914                 setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 915                 if (ast_bind(desc->accept_fd, &desc->local_address)) {
 916                         ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 917                                 desc->name,
 918                                 ast_sockaddr_stringify(&desc->local_address),
 919                                 strerror(errno));
 920                         goto error;
 921                 }
 922         }
 923
 924         if (!(tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor))) {
 925                 goto error;
 926         }
 927
 928         tcptls_session->overflow_buf = ast_str_create(128);
 929         tcptls_session->client = 1;
 930         tcptls_session->fd = desc->accept_fd;
 931         tcptls_session->parent = desc;
 932         tcptls_session->parent->worker_fn = NULL;
 933         ast_sockaddr_copy(&tcptls_session->remote_address,
 934                           &desc->remote_address);
 935
 936         /* Set current info */
 937         ast_sockaddr_copy(&desc->old_address, &desc->remote_address);
 938         return tcptls_session;
 939
 940 error:
 941         close(desc->accept_fd);
 942         desc->accept_fd = -1;
 943         if (tcptls_session) {
 944                 ao2_ref(tcptls_session, -1);
 945         }
 946         return NULL;
 947 }
 948
 949 void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 950 {
 951         int flags;
 952         int x = 1;
 953
 954         /* Do nothing if nothing has changed */
 955         if (!ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
 956                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 957                 return;
 958         }
 959
 960         /* If we return early, there is no one listening */
 961         ast_sockaddr_setnull(&desc->old_address);
 962
 963         /* Shutdown a running server if there is one */
 964         if (desc->master != AST_PTHREADT_NULL) {
 965                 pthread_cancel(desc->master);
 966                 pthread_kill(desc->master, SIGURG);
 967                 pthread_join(desc->master, NULL);
 968         }
 969
 970         if (desc->accept_fd != -1) {
 971                 close(desc->accept_fd);
 972         }
 973
 974         /* If there's no new server, stop here */
 975         if (ast_sockaddr_isnull(&desc->local_address)) {
 976                 ast_debug(2, "Server disabled:  %s\n", desc->name);
 977                 return;
 978         }
 979
 980         desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->local_address) ?
 981                                  AF_INET6 : AF_INET, SOCK_STREAM, 0);
 982         if (desc->accept_fd < 0) {
 983                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n", desc->name, strerror(errno));
 984                 return;
 985         }
 986
 987         setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 988         if (ast_bind(desc->accept_fd, &desc->local_address)) {
 989                 ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 990                         desc->name,
 991                         ast_sockaddr_stringify(&desc->local_address),
 992                         strerror(errno));
 993                 goto error;
 994         }
 995         if (listen(desc->accept_fd, 10)) {
 996                 ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
 997                 goto error;
 998         }
 999         flags = fcntl(desc->accept_fd, F_GETFL);
1000         fcntl(desc->accept_fd, F_SETFL, flags | O_NONBLOCK);
1001         if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
1002                 ast_log(LOG_ERROR, "Unable to launch thread for %s on %s: %s\n",
1003                         desc->name,
1004                         ast_sockaddr_stringify(&desc->local_address),
1005                         strerror(errno));
1006                 goto error;
1007         }
1008
1009         /* Set current info */
1010         ast_sockaddr_copy(&desc->old_address, &desc->local_address);
1011
1012         return;
1013
1014 error:
1015         close(desc->accept_fd);
1016         desc->accept_fd = -1;
1017 }
1018
1019 void ast_tcptls_close_session_file(struct ast_tcptls_session_instance *tcptls_session)
1020 {
1021         if (tcptls_session->f) {
1022                 fflush(tcptls_session->f);
1023                 if (fclose(tcptls_session->f)) {
1024                         ast_log(LOG_ERROR, "fclose() failed: %s\n", strerror(errno));
1025                 }
1026                 tcptls_session->f = NULL;
1027                 tcptls_session->fd = -1;
1028         } else if (tcptls_session->fd != -1) {
1029                 /*
1030                  * Issuing shutdown() is necessary here to avoid a race
1031                  * condition where the last data written may not appear
1032                  * in the TCP stream.  See ASTERISK-23548
1033                  */
1034                 shutdown(tcptls_session->fd, SHUT_RDWR);
1035                 if (close(tcptls_session->fd)) {
1036                         ast_log(LOG_ERROR, "close() failed: %s\n", strerror(errno));
1037                 }
1038                 tcptls_session->fd = -1;
1039         } else {
1040                 ast_log(LOG_ERROR, "ast_tcptls_close_session_file invoked on session instance without file or file descriptor\n");
1041         }
1042 }
1043
1044 void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
1045 {
1046         if (desc->master != AST_PTHREADT_NULL) {
1047                 pthread_cancel(desc->master);
1048                 pthread_kill(desc->master, SIGURG);
1049                 pthread_join(desc->master, NULL);
1050                 desc->master = AST_PTHREADT_NULL;
1051         }
1052         if (desc->accept_fd != -1) {
1053                 close(desc->accept_fd);
1054         }
1055         desc->accept_fd = -1;
1056         ast_debug(2, "Stopped server :: %s\n", desc->name);
1057 }
1058
1059 int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_args *tls_desc, const char *varname, const char *value)
1060 {
1061         if (!strcasecmp(varname, "tlsenable") || !strcasecmp(varname, "sslenable")) {
1062                 tls_cfg->enabled = ast_true(value) ? 1 : 0;
1063         } else if (!strcasecmp(varname, "tlscertfile") || !strcasecmp(varname, "sslcert") || !strcasecmp(varname, "tlscert")) {
1064                 ast_free(tls_cfg->certfile);
1065                 tls_cfg->certfile = ast_strdup(value);
1066         } else if (!strcasecmp(varname, "tlsprivatekey") || !strcasecmp(varname, "sslprivatekey")) {
1067                 ast_free(tls_cfg->pvtfile);
1068                 tls_cfg->pvtfile = ast_strdup(value);
1069         } else if (!strcasecmp(varname, "tlscipher") || !strcasecmp(varname, "sslcipher")) {
1070                 ast_free(tls_cfg->cipher);
1071                 tls_cfg->cipher = ast_strdup(value);
1072         } else if (!strcasecmp(varname, "tlscafile")) {
1073                 ast_free(tls_cfg->cafile);
1074                 tls_cfg->cafile = ast_strdup(value);
1075         } else if (!strcasecmp(varname, "tlscapath") || !strcasecmp(varname, "tlscadir")) {
1076                 ast_free(tls_cfg->capath);
1077                 tls_cfg->capath = ast_strdup(value);
1078         } else if (!strcasecmp(varname, "tlsverifyclient")) {
1079                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_VERIFY_CLIENT);
1080         } else if (!strcasecmp(varname, "tlsdontverifyserver")) {
1081                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DONT_VERIFY_SERVER);
1082         } else if (!strcasecmp(varname, "tlsbindaddr") || !strcasecmp(varname, "sslbindaddr")) {
1083                 if (ast_parse_arg(value, PARSE_ADDR, &tls_desc->local_address))
1084                         ast_log(LOG_ERROR, "Invalid %s '%s'\n", varname, value);
1085         } else if (!strcasecmp(varname, "tlsclientmethod") || !strcasecmp(varname, "sslclientmethod")) {
1086                 if (!strcasecmp(value, "tlsv1")) {
1087                         ast_set_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
1088                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
1089                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
1090                 } else if (!strcasecmp(value, "sslv3")) {
1091                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
1092                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
1093                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
1094                 } else if (!strcasecmp(value, "sslv2")) {
1095                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
1096                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
1097                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
1098                 }
1099         } else {
1100                 return -1;
1101         }
1102
1103         return 0;
1104 }