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 #include "asterisk/tcptls.h"            /* for ast_tls_config, ast_tcptls_se... */
  31 #include "asterisk/iostream.h"          /* for DO_SSL, ast_iostream_close, a... */
  32
  33 #ifdef HAVE_FCNTL_H
  34 #include <fcntl.h>                      /* for O_NONBLOCK */
  35 #endif /* HAVE_FCNTL_H */
  36 #include <netinet/in.h>                 /* for IPPROTO_TCP */
  37 #ifdef DO_SSL
  38 #include <openssl/asn1.h>               /* for ASN1_STRING_to_UTF8 */
  39 #include <openssl/crypto.h>             /* for OPENSSL_free */
  40 #include <openssl/opensslconf.h>        /* for OPENSSL_NO_SSL3_METHOD, OPENS... */
  41 #include <openssl/opensslv.h>           /* for OPENSSL_VERSION_NUMBER */
  42 #include <openssl/safestack.h>          /* for STACK_OF */
  43 #include <openssl/ssl.h>                /* for SSL_CTX_free, SSL_get_error, ... */
  44 #include <openssl/x509.h>               /* for X509_free, X509_NAME_ENTRY_ge... */
  45 #include <openssl/x509v3.h>             /* for GENERAL_NAME, sk_GENERAL_NAME... */
  46 #ifndef OPENSSL_NO_DH
  47 #include <openssl/bio.h>                /* for BIO_free, BIO_new_file */
  48 #include <openssl/dh.h>                 /* for DH_free */
  49 #include <openssl/pem.h>                /* for PEM_read_bio_DHparams */
  50 #endif /* OPENSSL_NO_DH */
  51 #ifndef OPENSSL_NO_EC
  52 #include <openssl/ec.h>                 /* for EC_KEY_free, EC_KEY_new_by_cu... */
  53 #endif /* OPENSSL_NO_EC */
  54 #endif /* DO_SSL */
  55 #include <pthread.h>                    /* for pthread_cancel, pthread_join */
  56 #include <signal.h>                     /* for pthread_kill, SIGURG */
  57 #include <sys/socket.h>                 /* for setsockopt, shutdown, socket */
  58 #include <sys/stat.h>                   /* for stat */
  59
  60 #include "asterisk/app.h"               /* for ast_read_textfile */
  61 #include "asterisk/astobj2.h"           /* for ao2_ref, ao2_t_ref, ao2_alloc */
  62 #include "asterisk/compat.h"            /* for strcasecmp */
  63 #include "asterisk/config.h"            /* for ast_parse_arg, ast_parse_flag... */
  64 #include "asterisk/io.h"                /* for ast_sd_get_fd */
  65 #include "asterisk/lock.h"              /* for AST_PTHREADT_NULL */
  66 #include "asterisk/logger.h"            /* for ast_log, LOG_ERROR, ast_debug */
  67 #include "asterisk/netsock2.h"          /* for ast_sockaddr_copy, ast_sockad... */
  68 #include "asterisk/pbx.h"               /* for ast_thread_inhibit_escalations */
  69 #include "asterisk/utils.h"             /* for ast_true, ast_free, ast_wait_... */
  70
  71 static void session_instance_destructor(void *obj)
  72 {
  73         struct ast_tcptls_session_instance *i = obj;
  74
  75         if (i->stream) {
  76                 ast_iostream_close(i->stream);
  77                 i->stream = NULL;
  78         }
  79         ast_free(i->overflow_buf);
  80         ao2_cleanup(i->private_data);
  81 }
  82
  83 #ifdef DO_SSL
  84 static int check_tcptls_cert_name(ASN1_STRING *cert_str, const char *hostname, const char *desc)
  85 {
  86         unsigned char *str;
  87         int ret;
  88
  89         ret = ASN1_STRING_to_UTF8(&str, cert_str);
  90         if (ret < 0 || !str) {
  91                 return -1;
  92         }
  93
  94         if (strlen((char *) str) != ret) {
  95                 ast_log(LOG_WARNING, "Invalid certificate %s length (contains NULL bytes?)\n", desc);
  96
  97                 ret = -1;
  98         } else if (!strcasecmp(hostname, (char *) str)) {
  99                 ret = 0;
 100         } else {
 101                 ret = -1;
 102         }
 103
 104         ast_debug(3, "SSL %s compare s1='%s' s2='%s'\n", desc, hostname, str);
 105         OPENSSL_free(str);
 106
 107         return ret;
 108 }
 109 #endif
 110
 111 /*! \brief
 112 * creates a FILE * from the fd passed by the accept thread.
 113 * This operation is potentially expensive (certificate verification),
 114 * so we do it in the child thread context.
 115 *
 116 * \note must decrement ref count before returning NULL on error
 117 */
 118 static void *handle_tcptls_connection(void *data)
 119 {
 120         struct ast_tcptls_session_instance *tcptls_session = data;
 121 #ifdef DO_SSL
 122         SSL *ssl;
 123 #endif
 124
 125         /* TCP/TLS connections are associated with external protocols, and
 126          * should not be allowed to execute 'dangerous' functions. This may
 127          * need to be pushed down into the individual protocol handlers, but
 128          * this seems like a good general policy.
 129          */
 130         if (ast_thread_inhibit_escalations()) {
 131                 ast_log(LOG_ERROR, "Failed to inhibit privilege escalations; killing connection\n");
 132                 ast_tcptls_close_session_file(tcptls_session);
 133                 ao2_ref(tcptls_session, -1);
 134                 return NULL;
 135         }
 136
 137         if (tcptls_session->parent->tls_cfg) {
 138 #ifdef DO_SSL
 139                 if (ast_iostream_start_tls(&tcptls_session->stream, tcptls_session->parent->tls_cfg->ssl_ctx, tcptls_session->client) < 0) {
 140                         ast_tcptls_close_session_file(tcptls_session);
 141                         ao2_ref(tcptls_session, -1);
 142                         return NULL;
 143                 }
 144
 145                 ssl = ast_iostream_get_ssl(tcptls_session->stream);
 146                 if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
 147                         || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
 148                         X509 *peer;
 149                         long res;
 150                         peer = SSL_get_peer_certificate(ssl);
 151                         if (!peer) {
 152                                 ast_log(LOG_ERROR, "No peer SSL certificate to verify\n");
 153                                 ast_tcptls_close_session_file(tcptls_session);
 154                                 ao2_ref(tcptls_session, -1);
 155                                 return NULL;
 156                         }
 157
 158                         res = SSL_get_verify_result(ssl);
 159                         if (res != X509_V_OK) {
 160                                 ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
 161                                 X509_free(peer);
 162                                 ast_tcptls_close_session_file(tcptls_session);
 163                                 ao2_ref(tcptls_session, -1);
 164                                 return NULL;
 165                         }
 166                         if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
 167                                 ASN1_STRING *str;
 168                                 X509_NAME *name = X509_get_subject_name(peer);
 169                                 STACK_OF(GENERAL_NAME) *alt_names;
 170                                 int pos = -1;
 171                                 int found = 0;
 172
 173                                 for (;;) {
 174                                         /* Walk the certificate to check all available "Common Name" */
 175                                         /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
 176                                         pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
 177                                         if (pos < 0) {
 178                                                 break;
 179                                         }
 180                                         str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
 181                                         if (!check_tcptls_cert_name(str, tcptls_session->parent->hostname, "common name")) {
 182                                                 found = 1;
 183                                                 break;
 184                                         }
 185                                 }
 186
 187                                 if (!found) {
 188                                         alt_names = X509_get_ext_d2i(peer, NID_subject_alt_name, NULL, NULL);
 189                                         if (alt_names != NULL) {
 190                                                 int alt_names_count = sk_GENERAL_NAME_num(alt_names);
 191
 192                                                 for (pos = 0; pos < alt_names_count; pos++) {
 193                                                         const GENERAL_NAME *alt_name = sk_GENERAL_NAME_value(alt_names, pos);
 194
 195                                                         if (alt_name->type != GEN_DNS) {
 196                                                                 continue;
 197                                                         }
 198
 199                                                         if (!check_tcptls_cert_name(alt_name->d.dNSName, tcptls_session->parent->hostname, "alt name")) {
 200                                                                 found = 1;
 201                                                                 break;
 202                                                         }
 203                                                 }
 204
 205                                                 sk_GENERAL_NAME_pop_free(alt_names, GENERAL_NAME_free);
 206                                         }
 207                                 }
 208
 209                                 if (!found) {
 210                                         ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
 211                                         X509_free(peer);
 212                                         ast_tcptls_close_session_file(tcptls_session);
 213                                         ao2_ref(tcptls_session, -1);
 214                                         return NULL;
 215                                 }
 216                         }
 217                         X509_free(peer);
 218                 }
 219 #else
 220                 ast_log(LOG_ERROR, "Attempted a TLS connection without OpenSSL support. This will not work!\n");
 221                 ast_tcptls_close_session_file(tcptls_session);
 222                 ao2_ref(tcptls_session, -1);
 223                 return NULL;
 224 #endif /* DO_SSL */
 225         }
 226
 227         if (tcptls_session->parent->worker_fn) {
 228                 return tcptls_session->parent->worker_fn(tcptls_session);
 229         } else {
 230                 return tcptls_session;
 231         }
 232 }
 233
 234 void *ast_tcptls_server_root(void *data)
 235 {
 236         struct ast_tcptls_session_args *desc = data;
 237         int fd;
 238         struct ast_sockaddr addr;
 239         struct ast_tcptls_session_instance *tcptls_session;
 240         pthread_t launched;
 241
 242         for (;;) {
 243                 int i;
 244
 245                 if (desc->periodic_fn) {
 246                         desc->periodic_fn(desc);
 247                 }
 248                 i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
 249                 if (i <= 0) {
 250                         /* Prevent tight loop from hogging CPU */
 251                         usleep(1);
 252                         continue;
 253                 }
 254                 fd = ast_accept(desc->accept_fd, &addr);
 255                 if (fd < 0) {
 256                         if (errno != EAGAIN
 257                                 && errno != EWOULDBLOCK
 258                                 && errno != EINTR
 259                                 && errno != ECONNABORTED) {
 260                                 ast_log(LOG_ERROR, "TCP/TLS accept failed: %s\n", strerror(errno));
 261                                 if (errno != EMFILE) {
 262                                         break;
 263                                 }
 264                         }
 265                         /* Prevent tight loop from hogging CPU */
 266                         usleep(1);
 267                         continue;
 268                 }
 269                 tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
 270                 if (!tcptls_session) {
 271                         close(fd);
 272                         continue;
 273                 }
 274
 275                 tcptls_session->overflow_buf = ast_str_create(128);
 276                 if (!tcptls_session->overflow_buf) {
 277                         ao2_ref(tcptls_session, -1);
 278                         close(fd);
 279                         continue;
 280                 }
 281                 ast_fd_clear_flags(fd, O_NONBLOCK);
 282
 283                 tcptls_session->stream = ast_iostream_from_fd(&fd);
 284                 if (!tcptls_session->stream) {
 285                         ao2_ref(tcptls_session, -1);
 286                         close(fd);
 287                         continue;
 288                 }
 289
 290                 tcptls_session->parent = desc;
 291                 ast_sockaddr_copy(&tcptls_session->remote_address, &addr);
 292
 293                 tcptls_session->client = 0;
 294
 295                 /* This thread is now the only place that controls the single ref to tcptls_session */
 296                 if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
 297                         ast_log(LOG_ERROR, "TCP/TLS unable to launch helper thread: %s\n",
 298                                 strerror(errno));
 299                         ao2_ref(tcptls_session, -1);
 300                 }
 301         }
 302
 303         ast_log(LOG_ERROR, "TCP/TLS listener thread ended abnormally\n");
 304
 305         /* Close the listener socket so Asterisk doesn't appear dead. */
 306         fd = desc->accept_fd;
 307         desc->accept_fd = -1;
 308         if (0 <= fd) {
 309                 close(fd);
 310         }
 311         return NULL;
 312 }
 313
 314 #ifdef DO_SSL
 315 static void __ssl_setup_certs(struct ast_tls_config *cfg, const size_t cert_file_len, const char *key_type_extension, const char *key_type)
 316 {
 317         char *cert_file = ast_strdupa(cfg->certfile);
 318
 319         memcpy(cert_file + cert_file_len - 8, key_type_extension, 5);
 320         if (access(cert_file, F_OK) == 0) {
 321                 if (SSL_CTX_use_certificate_chain_file(cfg->ssl_ctx, cert_file) == 0) {
 322                         ast_log(LOG_WARNING, "TLS/SSL error loading public %s key (certificate) from <%s>.\n", key_type, cert_file);
 323                 } else if (SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, cert_file, SSL_FILETYPE_PEM) == 0) {
 324                         ast_log(LOG_WARNING, "TLS/SSL error loading private %s key from <%s>.\n", key_type, cert_file);
 325                 } else if (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0) {
 326                         ast_log(LOG_WARNING, "TLS/SSL error matching private %s key and certificate in <%s>.\n", key_type, cert_file);
 327                 }
 328         }
 329 }
 330 #endif
 331
 332 static int __ssl_setup(struct ast_tls_config *cfg, int client)
 333 {
 334 #ifndef DO_SSL
 335         if (cfg->enabled) {
 336                 ast_log(LOG_NOTICE, "Configured without OpenSSL Development Headers");
 337                 cfg->enabled = 0;
 338         }
 339         return 0;
 340 #else
 341         int disable_ssl = 0;
 342         long ssl_opts = 0;
 343
 344         if (!cfg->enabled) {
 345                 return 0;
 346         }
 347
 348         /* Get rid of an old SSL_CTX since we're about to
 349          * allocate a new one
 350          */
 351         if (cfg->ssl_ctx) {
 352                 SSL_CTX_free(cfg->ssl_ctx);
 353                 cfg->ssl_ctx = NULL;
 354         }
 355
 356         if (client) {
 357 #if !defined(OPENSSL_NO_SSL2) && (OPENSSL_VERSION_NUMBER < 0x10100000L)
 358                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV2_CLIENT)) {
 359                         ast_log(LOG_WARNING, "Usage of SSLv2 is discouraged due to known vulnerabilities. Please use 'tlsv1' or leave the TLS method unspecified!\n");
 360                         cfg->ssl_ctx = SSL_CTX_new(SSLv2_client_method());
 361                 } else
 362 #endif
 363 #if !defined(OPENSSL_NO_SSL3_METHOD) && !(defined(OPENSSL_API_COMPAT) && (OPENSSL_API_COMPAT >= 0x10100000L))
 364                 if (ast_test_flag(&cfg->flags, AST_SSL_SSLV3_CLIENT)) {
 365                         ast_log(LOG_WARNING, "Usage of SSLv3 is discouraged due to known vulnerabilities. Please use 'tlsv1' or leave the TLS method unspecified!\n");
 366                         cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());
 367                 } else
 368 #endif
 369 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
 370                 cfg->ssl_ctx = SSL_CTX_new(TLS_client_method());
 371 #else
 372                 if (ast_test_flag(&cfg->flags, AST_SSL_TLSV1_CLIENT)) {
 373                         cfg->ssl_ctx = SSL_CTX_new(TLSv1_client_method());
 374                 } else {
 375                         disable_ssl = 1;
 376                         cfg->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
 377                 }
 378 #endif
 379         } else {
 380                 disable_ssl = 1;
 381                 cfg->ssl_ctx = SSL_CTX_new(SSLv23_server_method());
 382         }
 383
 384         if (!cfg->ssl_ctx) {
 385                 ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
 386                 cfg->enabled = 0;
 387                 return 0;
 388         }
 389
 390         /* Due to the POODLE vulnerability, completely disable
 391          * SSLv2 and SSLv3 if we are not explicitly told to use
 392          * them. SSLv23_*_method supports TLSv1+.
 393          */
 394         if (disable_ssl) {
 395                 ssl_opts |= SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
 396         }
 397
 398         if (ast_test_flag(&cfg->flags, AST_SSL_SERVER_CIPHER_ORDER)) {
 399                 ssl_opts |= SSL_OP_CIPHER_SERVER_PREFERENCE;
 400         }
 401
 402         if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV1)) {
 403                 ssl_opts |= SSL_OP_NO_TLSv1;
 404         }
 405 #if defined(SSL_OP_NO_TLSv1_1) && defined(SSL_OP_NO_TLSv1_2)
 406         if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV11)) {
 407                 ssl_opts |= SSL_OP_NO_TLSv1_1;
 408         }
 409         if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV12)) {
 410                 ssl_opts |= SSL_OP_NO_TLSv1_2;
 411         }
 412 #else
 413         ast_log(LOG_WARNING, "Your version of OpenSSL leaves you potentially vulnerable "
 414                         "to the SSL BEAST attack. Please upgrade to OpenSSL 1.0.1 or later\n");
 415 #endif
 416
 417         SSL_CTX_set_options(cfg->ssl_ctx, ssl_opts);
 418
 419         SSL_CTX_set_verify(cfg->ssl_ctx,
 420                 ast_test_flag(&cfg->flags, AST_SSL_VERIFY_CLIENT) ? SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT : SSL_VERIFY_NONE,
 421                 NULL);
 422
 423         if (!ast_strlen_zero(cfg->certfile)) {
 424                 char *tmpprivate = ast_strlen_zero(cfg->pvtfile) ? cfg->certfile : cfg->pvtfile;
 425                 if (SSL_CTX_use_certificate_chain_file(cfg->ssl_ctx, cfg->certfile) == 0) {
 426                         if (!client) {
 427                                 /* Clients don't need a certificate, but if its setup we can use it */
 428                                 ast_log(LOG_ERROR, "TLS/SSL error loading cert file. <%s>\n", cfg->certfile);
 429                                 cfg->enabled = 0;
 430                                 SSL_CTX_free(cfg->ssl_ctx);
 431                                 cfg->ssl_ctx = NULL;
 432                                 return 0;
 433                         }
 434                 }
 435                 if ((SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, tmpprivate, SSL_FILETYPE_PEM) == 0) || (SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 )) {
 436                         if (!client) {
 437                                 /* Clients don't need a private key, but if its setup we can use it */
 438                                 ast_log(LOG_ERROR, "TLS/SSL error loading private key file. <%s>\n", tmpprivate);
 439                                 cfg->enabled = 0;
 440                                 SSL_CTX_free(cfg->ssl_ctx);
 441                                 cfg->ssl_ctx = NULL;
 442                                 return 0;
 443                         }
 444                 }
 445                 if (!client) {
 446                         size_t certfile_len = strlen(cfg->certfile);
 447
 448                         /* expects a file name which contains _rsa. like asterisk_rsa.pem
 449                          * ignores any 3-character file-extension like .pem, .cer, .crt
 450                          */
 451                         if (certfile_len >= 8 && !strncmp(cfg->certfile + certfile_len - 8, "_rsa.", 5)) {
 452                                 __ssl_setup_certs(cfg, certfile_len, "_ecc.", "ECC");
 453                                 __ssl_setup_certs(cfg, certfile_len, "_dsa.", "DSA");
 454                         }
 455                 }
 456         }
 457         if (!ast_strlen_zero(cfg->cipher)) {
 458                 if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
 459                         if (!client) {
 460                                 ast_log(LOG_ERROR, "TLS/SSL cipher error <%s>\n", cfg->cipher);
 461                                 cfg->enabled = 0;
 462                                 SSL_CTX_free(cfg->ssl_ctx);
 463                                 cfg->ssl_ctx = NULL;
 464                                 return 0;
 465                         }
 466                 }
 467         }
 468         if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
 469                 if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0) {
 470                         ast_log(LOG_ERROR, "TLS/SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
 471                 }
 472         }
 473
 474 #ifdef HAVE_OPENSSL_EC
 475
 476         if (!ast_strlen_zero(cfg->pvtfile)) {
 477                 BIO *bio = BIO_new_file(cfg->pvtfile, "r");
 478                 if (bio != NULL) {
 479                         DH *dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
 480                         if (dh != NULL) {
 481                                 if (SSL_CTX_set_tmp_dh(cfg->ssl_ctx, dh)) {
 482                                         long options = SSL_OP_CIPHER_SERVER_PREFERENCE | SSL_OP_SINGLE_DH_USE | SSL_OP_SINGLE_ECDH_USE;
 483                                         options = SSL_CTX_set_options(cfg->ssl_ctx, options);
 484                                         ast_verb(2, "TLS/SSL DH initialized, PFS cipher-suites enabled\n");
 485                                 }
 486                                 DH_free(dh);
 487                         }
 488                         BIO_free(bio);
 489                 }
 490         }
 491         #ifndef SSL_CTRL_SET_ECDH_AUTO
 492                 #define SSL_CTRL_SET_ECDH_AUTO 94
 493         #endif
 494         /* SSL_CTX_set_ecdh_auto(cfg->ssl_ctx, on); requires OpenSSL 1.0.2 which wraps: */
 495         if (SSL_CTX_ctrl(cfg->ssl_ctx, SSL_CTRL_SET_ECDH_AUTO, 1, NULL)) {
 496                 ast_verb(2, "TLS/SSL ECDH initialized (automatic), faster PFS ciphers enabled\n");
 497         } else {
 498                 /* enables AES-128 ciphers, to get AES-256 use NID_secp384r1 */
 499                 EC_KEY *ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
 500                 if (ecdh != NULL) {
 501                         if (SSL_CTX_set_tmp_ecdh(cfg->ssl_ctx, ecdh)) {
 502                                 ast_verb(2, "TLS/SSL ECDH initialized (secp256r1), faster PFS cipher-suites enabled\n");
 503                         }
 504                         EC_KEY_free(ecdh);
 505                 }
 506         }
 507
 508 #endif /* #ifdef HAVE_OPENSSL_EC */
 509
 510         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 */
 511         return 1;
 512 #endif
 513 }
 514
 515 int ast_ssl_setup(struct ast_tls_config *cfg)
 516 {
 517         return __ssl_setup(cfg, 0);
 518 }
 519
 520 void ast_ssl_teardown(struct ast_tls_config *cfg)
 521 {
 522 #ifdef DO_SSL
 523         if (cfg && cfg->ssl_ctx) {
 524                 SSL_CTX_free(cfg->ssl_ctx);
 525                 cfg->ssl_ctx = NULL;
 526         }
 527 #endif
 528 }
 529
 530 struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_instance *tcptls_session)
 531 {
 532         struct ast_tcptls_session_args *desc;
 533
 534         if (!(desc = tcptls_session->parent)) {
 535                 goto client_start_error;
 536         }
 537
 538         if (ast_connect(desc->accept_fd, &desc->remote_address)) {
 539                 ast_log(LOG_ERROR, "Unable to connect %s to %s: %s\n",
 540                         desc->name,
 541                         ast_sockaddr_stringify(&desc->remote_address),
 542                         strerror(errno));
 543                 goto client_start_error;
 544         }
 545
 546         ast_fd_clear_flags(desc->accept_fd, O_NONBLOCK);
 547
 548         if (desc->tls_cfg) {
 549                 desc->tls_cfg->enabled = 1;
 550                 __ssl_setup(desc->tls_cfg, 1);
 551         }
 552
 553         return handle_tcptls_connection(tcptls_session);
 554
 555 client_start_error:
 556         if (desc) {
 557                 close(desc->accept_fd);
 558                 desc->accept_fd = -1;
 559         }
 560         ao2_ref(tcptls_session, -1);
 561         return NULL;
 562
 563 }
 564
 565 struct ast_tcptls_session_instance *ast_tcptls_client_create(struct ast_tcptls_session_args *desc)
 566 {
 567         int fd, x = 1;
 568         struct ast_tcptls_session_instance *tcptls_session = NULL;
 569
 570         /* Do nothing if nothing has changed */
 571         if (!ast_sockaddr_cmp(&desc->old_address, &desc->remote_address)) {
 572                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 573                 return NULL;
 574         }
 575
 576         /* If we return early, there is no connection */
 577         ast_sockaddr_setnull(&desc->old_address);
 578
 579         if (desc->accept_fd != -1) {
 580                 close(desc->accept_fd);
 581         }
 582
 583         fd = desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->remote_address) ?
 584                                       AF_INET6 : AF_INET, SOCK_STREAM, IPPROTO_TCP);
 585         if (desc->accept_fd < 0) {
 586                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n",
 587                         desc->name, strerror(errno));
 588                 return NULL;
 589         }
 590
 591         /* if a local address was specified, bind to it so the connection will
 592            originate from the desired address */
 593         if (!ast_sockaddr_isnull(&desc->local_address) &&
 594             !ast_sockaddr_is_any(&desc->local_address)) {
 595                 setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 596                 if (ast_bind(desc->accept_fd, &desc->local_address)) {
 597                         ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 598                                 desc->name,
 599                                 ast_sockaddr_stringify(&desc->local_address),
 600                                 strerror(errno));
 601                         goto error;
 602                 }
 603         }
 604
 605         tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
 606         if (!tcptls_session) {
 607                 goto error;
 608         }
 609
 610         tcptls_session->overflow_buf = ast_str_create(128);
 611         if (!tcptls_session->overflow_buf) {
 612                 goto error;
 613         }
 614         tcptls_session->client = 1;
 615         tcptls_session->stream = ast_iostream_from_fd(&fd);
 616         if (!tcptls_session->stream) {
 617                 goto error;
 618         }
 619
 620         tcptls_session->parent = desc;
 621         tcptls_session->parent->worker_fn = NULL;
 622         ast_sockaddr_copy(&tcptls_session->remote_address,
 623                           &desc->remote_address);
 624
 625         /* Set current info */
 626         ast_sockaddr_copy(&desc->old_address, &desc->remote_address);
 627         return tcptls_session;
 628
 629 error:
 630         close(desc->accept_fd);
 631         desc->accept_fd = -1;
 632         ao2_cleanup(tcptls_session);
 633         return NULL;
 634 }
 635
 636 void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 637 {
 638         int x = 1;
 639         int tls_changed = 0;
 640         int sd_socket;
 641
 642         if (desc->tls_cfg) {
 643                 char hash[41];
 644                 char *str = NULL;
 645                 struct stat st;
 646
 647                 /* Store the hashes of the TLS certificate etc. */
 648                 if (stat(desc->tls_cfg->certfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->certfile))) {
 649                         memset(hash, 0, 41);
 650                 } else {
 651                         ast_sha1_hash(hash, str);
 652                 }
 653                 ast_free(str);
 654                 str = NULL;
 655                 memcpy(desc->tls_cfg->certhash, hash, 41);
 656                 if (stat(desc->tls_cfg->pvtfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->pvtfile))) {
 657                         memset(hash, 0, 41);
 658                 } else {
 659                         ast_sha1_hash(hash, str);
 660                 }
 661                 ast_free(str);
 662                 str = NULL;
 663                 memcpy(desc->tls_cfg->pvthash, hash, 41);
 664                 if (stat(desc->tls_cfg->cafile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->cafile))) {
 665                         memset(hash, 0, 41);
 666                 } else {
 667                         ast_sha1_hash(hash, str);
 668                 }
 669                 ast_free(str);
 670                 str = NULL;
 671                 memcpy(desc->tls_cfg->cahash, hash, 41);
 672
 673                 /* Check whether TLS configuration has changed */
 674                 if (!desc->old_tls_cfg) { /* No previous configuration */
 675                         tls_changed = 1;
 676                         desc->old_tls_cfg = ast_calloc(1, sizeof(*desc->old_tls_cfg));
 677                 } else if (memcmp(desc->tls_cfg->certhash, desc->old_tls_cfg->certhash, 41)) {
 678                         tls_changed = 1;
 679                 } else if (memcmp(desc->tls_cfg->pvthash, desc->old_tls_cfg->pvthash, 41)) {
 680                         tls_changed = 1;
 681                 } else if (strcmp(desc->tls_cfg->cipher, desc->old_tls_cfg->cipher)) {
 682                         tls_changed = 1;
 683                 } else if (memcmp(desc->tls_cfg->cahash, desc->old_tls_cfg->cahash, 41)) {
 684                         tls_changed = 1;
 685                 } else if (strcmp(desc->tls_cfg->capath, desc->old_tls_cfg->capath)) {
 686                         tls_changed = 1;
 687                 } else if (memcmp(&desc->tls_cfg->flags, &desc->old_tls_cfg->flags, sizeof(desc->tls_cfg->flags))) {
 688                         tls_changed = 1;
 689                 }
 690
 691                 if (tls_changed) {
 692                         ast_debug(1, "Changed parameters for %s found\n", desc->name);
 693                 }
 694         }
 695
 696         /* Do nothing if nothing has changed */
 697         if (!tls_changed && !ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
 698                 ast_debug(1, "Nothing changed in %s\n", desc->name);
 699                 return;
 700         }
 701
 702         /* If we return early, there is no one listening */
 703         ast_sockaddr_setnull(&desc->old_address);
 704
 705         /* Shutdown a running server if there is one */
 706         if (desc->master != AST_PTHREADT_NULL) {
 707                 pthread_cancel(desc->master);
 708                 pthread_kill(desc->master, SIGURG);
 709                 pthread_join(desc->master, NULL);
 710         }
 711
 712         sd_socket = ast_sd_get_fd(SOCK_STREAM, &desc->local_address);
 713
 714         if (sd_socket != -1) {
 715                 if (desc->accept_fd != sd_socket) {
 716                         if (desc->accept_fd != -1) {
 717                                 close(desc->accept_fd);
 718                         }
 719                         desc->accept_fd = sd_socket;
 720                 }
 721
 722                 goto systemd_socket_activation;
 723         }
 724
 725         if (desc->accept_fd != -1) {
 726                 close(desc->accept_fd);
 727         }
 728
 729         /* If there's no new server, stop here */
 730         if (ast_sockaddr_isnull(&desc->local_address)) {
 731                 ast_debug(2, "Server disabled:  %s\n", desc->name);
 732                 return;
 733         }
 734
 735         desc->accept_fd = socket(ast_sockaddr_is_ipv6(&desc->local_address) ?
 736                                  AF_INET6 : AF_INET, SOCK_STREAM, 0);
 737         if (desc->accept_fd < 0) {
 738                 ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n", desc->name, strerror(errno));
 739                 return;
 740         }
 741
 742         setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
 743         if (ast_bind(desc->accept_fd, &desc->local_address)) {
 744                 ast_log(LOG_ERROR, "Unable to bind %s to %s: %s\n",
 745                         desc->name,
 746                         ast_sockaddr_stringify(&desc->local_address),
 747                         strerror(errno));
 748                 goto error;
 749         }
 750         if (listen(desc->accept_fd, 10)) {
 751                 ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
 752                 goto error;
 753         }
 754
 755 systemd_socket_activation:
 756         ast_fd_set_flags(desc->accept_fd, O_NONBLOCK);
 757         if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
 758                 ast_log(LOG_ERROR, "Unable to launch thread for %s on %s: %s\n",
 759                         desc->name,
 760                         ast_sockaddr_stringify(&desc->local_address),
 761                         strerror(errno));
 762                 goto error;
 763         }
 764
 765         /* Set current info */
 766         ast_sockaddr_copy(&desc->old_address, &desc->local_address);
 767         if (desc->old_tls_cfg) {
 768                 ast_free(desc->old_tls_cfg->certfile);
 769                 ast_free(desc->old_tls_cfg->pvtfile);
 770                 ast_free(desc->old_tls_cfg->cipher);
 771                 ast_free(desc->old_tls_cfg->cafile);
 772                 ast_free(desc->old_tls_cfg->capath);
 773                 desc->old_tls_cfg->certfile = ast_strdup(desc->tls_cfg->certfile);
 774                 desc->old_tls_cfg->pvtfile = ast_strdup(desc->tls_cfg->pvtfile);
 775                 desc->old_tls_cfg->cipher = ast_strdup(desc->tls_cfg->cipher);
 776                 desc->old_tls_cfg->cafile = ast_strdup(desc->tls_cfg->cafile);
 777                 desc->old_tls_cfg->capath = ast_strdup(desc->tls_cfg->capath);
 778                 memcpy(desc->old_tls_cfg->certhash, desc->tls_cfg->certhash, 41);
 779                 memcpy(desc->old_tls_cfg->pvthash, desc->tls_cfg->pvthash, 41);
 780                 memcpy(desc->old_tls_cfg->cahash, desc->tls_cfg->cahash, 41);
 781                 memcpy(&desc->old_tls_cfg->flags, &desc->tls_cfg->flags, sizeof(desc->old_tls_cfg->flags));
 782         }
 783
 784         return;
 785
 786 error:
 787         close(desc->accept_fd);
 788         desc->accept_fd = -1;
 789 }
 790
 791 void ast_tcptls_close_session_file(struct ast_tcptls_session_instance *tcptls_session)
 792 {
 793         if (tcptls_session->stream) {
 794                 ast_iostream_close(tcptls_session->stream);
 795                 tcptls_session->stream = NULL;
 796         } else {
 797                 ast_debug(1, "ast_tcptls_close_session_file invoked on session instance without file or file descriptor\n");
 798         }
 799 }
 800
 801 void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
 802 {
 803         if (desc->master != AST_PTHREADT_NULL) {
 804                 pthread_cancel(desc->master);
 805                 pthread_kill(desc->master, SIGURG);
 806                 pthread_join(desc->master, NULL);
 807                 desc->master = AST_PTHREADT_NULL;
 808         }
 809         if (desc->accept_fd != -1) {
 810                 close(desc->accept_fd);
 811         }
 812         desc->accept_fd = -1;
 813
 814         if (desc->old_tls_cfg) {
 815                 ast_free(desc->old_tls_cfg->certfile);
 816                 ast_free(desc->old_tls_cfg->pvtfile);
 817                 ast_free(desc->old_tls_cfg->cipher);
 818                 ast_free(desc->old_tls_cfg->cafile);
 819                 ast_free(desc->old_tls_cfg->capath);
 820                 ast_free(desc->old_tls_cfg);
 821                 desc->old_tls_cfg = NULL;
 822         }
 823
 824         ast_debug(2, "Stopped server :: %s\n", desc->name);
 825 }
 826
 827 int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_args *tls_desc, const char *varname, const char *value)
 828 {
 829         if (!strcasecmp(varname, "tlsenable") || !strcasecmp(varname, "sslenable")) {
 830                 tls_cfg->enabled = ast_true(value) ? 1 : 0;
 831         } else if (!strcasecmp(varname, "tlscertfile") || !strcasecmp(varname, "sslcert") || !strcasecmp(varname, "tlscert")) {
 832                 ast_free(tls_cfg->certfile);
 833                 tls_cfg->certfile = ast_strdup(value);
 834         } else if (!strcasecmp(varname, "tlsprivatekey") || !strcasecmp(varname, "sslprivatekey")) {
 835                 ast_free(tls_cfg->pvtfile);
 836                 tls_cfg->pvtfile = ast_strdup(value);
 837         } else if (!strcasecmp(varname, "tlscipher") || !strcasecmp(varname, "sslcipher")) {
 838                 ast_free(tls_cfg->cipher);
 839                 tls_cfg->cipher = ast_strdup(value);
 840         } else if (!strcasecmp(varname, "tlscafile")) {
 841                 ast_free(tls_cfg->cafile);
 842                 tls_cfg->cafile = ast_strdup(value);
 843         } else if (!strcasecmp(varname, "tlscapath") || !strcasecmp(varname, "tlscadir")) {
 844                 ast_free(tls_cfg->capath);
 845                 tls_cfg->capath = ast_strdup(value);
 846         } else if (!strcasecmp(varname, "tlsverifyclient")) {
 847                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_VERIFY_CLIENT);
 848         } else if (!strcasecmp(varname, "tlsdontverifyserver")) {
 849                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DONT_VERIFY_SERVER);
 850         } else if (!strcasecmp(varname, "tlsbindaddr") || !strcasecmp(varname, "sslbindaddr")) {
 851                 if (ast_parse_arg(value, PARSE_ADDR, &tls_desc->local_address))
 852                         ast_log(LOG_ERROR, "Invalid %s '%s'\n", varname, value);
 853         } else if (!strcasecmp(varname, "tlsclientmethod") || !strcasecmp(varname, "sslclientmethod")) {
 854                 if (!strcasecmp(value, "tlsv1")) {
 855                         ast_set_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 856                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 857                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 858                 } else if (!strcasecmp(value, "sslv3")) {
 859                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 860                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 861                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 862                 } else if (!strcasecmp(value, "sslv2")) {
 863                         ast_set_flag(&tls_cfg->flags, AST_SSL_SSLV2_CLIENT);
 864                         ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
 865                         ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
 866                 }
 867         } else if (!strcasecmp(varname, "tlsservercipherorder")) {
 868                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_SERVER_CIPHER_ORDER);
 869         } else if (!strcasecmp(varname, "tlsdisablev1")) {
 870                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV1);
 871         } else if (!strcasecmp(varname, "tlsdisablev11")) {
 872                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV11);
 873         } else if (!strcasecmp(varname, "tlsdisablev12")) {
 874                 ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV12);
 875         } else {
 876                 return -1;
 877         }
 878
 879         return 0;
 880 }