_ Git - BearSSL/blob - tools/server.c

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <stdint.h>
  29 #include <errno.h>
  30
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33 #include <netdb.h>
  34 #include <netinet/in.h>
  35 #include <arpa/inet.h>
  36 #include <unistd.h>
  37 #include <fcntl.h>
  38
  39 #include "brssl.h"
  40 #include "bearssl.h"
  41
  42 static int
  43 host_bind(const char *host, const char *port, int verbose)
  44 {
  45         struct addrinfo hints, *si, *p;
  46         int fd;
  47         int err;
  48
  49         memset(&hints, 0, sizeof hints);
  50         hints.ai_family = PF_UNSPEC;
  51         hints.ai_socktype = SOCK_STREAM;
  52         err = getaddrinfo(host, port, &hints, &si);
  53         if (err != 0) {
  54                 fprintf(stderr, "ERROR: getaddrinfo(): %s\n",
  55                         gai_strerror(err));
  56                 return -1;
  57         }
  58         fd = -1;
  59         for (p = si; p != NULL; p = p->ai_next) {
  60                 struct sockaddr *sa;
  61                 struct sockaddr_in sa4;
  62                 struct sockaddr_in6 sa6;
  63                 size_t sa_len;
  64                 void *addr;
  65                 char tmp[INET6_ADDRSTRLEN + 50];
  66                 int opt;
  67
  68                 sa = (struct sockaddr *)p->ai_addr;
  69                 if (sa->sa_family == AF_INET) {
  70                         sa4 = *(struct sockaddr_in *)sa;
  71                         sa = (struct sockaddr *)&sa4;
  72                         sa_len = sizeof sa4;
  73                         addr = &sa4.sin_addr;
  74                         if (host == NULL) {
  75                                 sa4.sin_addr.s_addr = INADDR_ANY;
  76                         }
  77                 } else if (sa->sa_family == AF_INET6) {
  78                         sa6 = *(struct sockaddr_in6 *)sa;
  79                         sa = (struct sockaddr *)&sa6;
  80                         sa_len = sizeof sa6;
  81                         addr = &sa6.sin6_addr;
  82                         if (host == NULL) {
  83                                 sa6.sin6_addr = in6addr_any;
  84                         }
  85                 } else {
  86                         addr = NULL;
  87                         sa_len = p->ai_addrlen;
  88                 }
  89                 if (addr != NULL) {
  90                         inet_ntop(p->ai_family, addr, tmp, sizeof tmp);
  91                 } else {
  92                         sprintf(tmp, "<unknown family: %d>",
  93                                 (int)sa->sa_family);
  94                 }
  95                 if (verbose) {
  96                         fprintf(stderr, "binding to: %s\n", tmp);
  97                 }
  98                 fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
  99                 if (fd < 0) {
 100                         if (verbose) {
 101                                 perror("socket()");
 102                         }
 103                         continue;
 104                 }
 105                 opt = 1;
 106                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof opt);
 107                 opt = 0;
 108                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof opt);
 109                 if (bind(fd, sa, sa_len) < 0) {
 110                         if (verbose) {
 111                                 perror("bind()");
 112                         }
 113                         close(fd);
 114                         continue;
 115                 }
 116                 break;
 117         }
 118         if (p == NULL) {
 119                 freeaddrinfo(si);
 120                 fprintf(stderr, "ERROR: failed to bind\n");
 121                 return -1;
 122         }
 123         freeaddrinfo(si);
 124         if (listen(fd, 5) < 0) {
 125                 if (verbose) {
 126                         perror("listen()");
 127                 }
 128                 close(fd);
 129                 return -1;
 130         }
 131         if (verbose) {
 132                 fprintf(stderr, "bound.\n");
 133         }
 134         return fd;
 135 }
 136
 137 static int
 138 accept_client(int server_fd, int verbose)
 139 {
 140         int fd;
 141         struct sockaddr sa;
 142         socklen_t sa_len;
 143
 144         sa_len = sizeof sa;
 145         fd = accept(server_fd, &sa, &sa_len);
 146         if (fd < 0) {
 147                 if (verbose) {
 148                         perror("accept()");
 149                 }
 150                 return -1;
 151         }
 152         if (verbose) {
 153                 char tmp[INET6_ADDRSTRLEN + 50];
 154                 const char *name;
 155
 156                 name = NULL;
 157                 switch (sa.sa_family) {
 158                 case AF_INET:
 159                         name = inet_ntop(AF_INET,
 160                                 &((struct sockaddr_in *)&sa)->sin_addr,
 161                                 tmp, sizeof tmp);
 162                         break;
 163                 case AF_INET6:
 164                         name = inet_ntop(AF_INET6,
 165                                 &((struct sockaddr_in6 *)&sa)->sin6_addr,
 166                                 tmp, sizeof tmp);
 167                         break;
 168                 }
 169                 if (name == NULL) {
 170                         sprintf(tmp, "<unknown: %lu>",
 171                                 (unsigned long)sa.sa_family);
 172                         name = tmp;
 173                 }
 174                 fprintf(stderr, "accepting connection from: %s\n", name);
 175         }
 176
 177         /*
 178          * We make the socket non-blocking, since we are going to use
 179          * poll() to organise I/O.
 180          */
 181         fcntl(fd, F_SETFL, O_NONBLOCK);
 182         return fd;
 183 }
 184
 185 static void
 186 usage_server(void)
 187 {
 188         fprintf(stderr,
 189 "usage: brssl server [ options ]\n");
 190         fprintf(stderr,
 191 "options:\n");
 192         fprintf(stderr,
 193 "   -q              suppress verbose messages\n");
 194         fprintf(stderr,
 195 "   -trace          activate extra debug messages (dump of all packets)\n");
 196         fprintf(stderr,
 197 "   -b name         bind to a specific address or host name\n");
 198         fprintf(stderr,
 199 "   -p port         bind to a specific port (default: 4433)\n");
 200         fprintf(stderr,
 201 "   -mono           use monodirectional buffering\n");
 202         fprintf(stderr,
 203 "   -buf length     set the I/O buffer length (in bytes)\n");
 204         fprintf(stderr,
 205 "   -cache length   set the session cache storage length (in bytes)\n");
 206         fprintf(stderr,
 207 "   -cert fname     read certificate chain from file 'fname'\n");
 208         fprintf(stderr,
 209 "   -key fname      read private key from file 'fname'\n");
 210         fprintf(stderr,
 211 "   -list           list supported names (protocols, algorithms...)\n");
 212         fprintf(stderr,
 213 "   -vmin name      set minimum supported version (default: TLS-1.0)\n");
 214         fprintf(stderr,
 215 "   -vmax name      set maximum supported version (default: TLS-1.2)\n");
 216         fprintf(stderr,
 217 "   -cs names       set list of supported cipher suites (comma-separated)\n");
 218         fprintf(stderr,
 219 "   -hf names       add support for some hash functions (comma-separated)\n");
 220         fprintf(stderr,
 221 "   -serverpref     enforce server's preferences for cipher suites\n");
 222         exit(EXIT_FAILURE);
 223 }
 224
 225 typedef struct {
 226         const br_ssl_server_policy_class *vtable;
 227         int verbose;
 228         br_x509_certificate *chain;
 229         size_t chain_len;
 230         int cert_signer_algo;
 231         private_key *sk;
 232 } policy_context;
 233
 234 static int
 235 get_cert_signer_algo(br_x509_certificate *xc)
 236 {
 237         br_x509_decoder_context dc;
 238         int err;
 239
 240         br_x509_decoder_init(&dc, 0, 0);
 241         br_x509_decoder_push(&dc, xc->data, xc->data_len);
 242         err = br_x509_decoder_last_error(&dc);
 243         if (err != 0) {
 244                 return -err;
 245         } else {
 246                 return br_x509_decoder_get_signer_key_type(&dc);
 247         }
 248 }
 249
 250 static int
 251 sp_choose(const br_ssl_server_policy_class **pctx,
 252         const br_ssl_server_context *cc,
 253         br_ssl_server_choices *choices)
 254 {
 255         policy_context *pc;
 256         const br_suite_translated *st;
 257         size_t u, st_num;
 258         unsigned chashes;
 259         int hash_id;
 260
 261         pc = (policy_context *)pctx;
 262         st = br_ssl_server_get_client_suites(cc, &st_num);
 263         chashes = br_ssl_server_get_client_hashes(cc);
 264         for (hash_id = 6; hash_id >= 2; hash_id --) {
 265                 if ((chashes >> hash_id) & 1) {
 266                         break;
 267                 }
 268         }
 269         if (pc->verbose) {
 270                 fprintf(stderr, "Client parameters:\n");
 271                 fprintf(stderr, "   Maximum version:      ");
 272                 switch (cc->client_max_version) {
 273                 case BR_SSL30:
 274                         fprintf(stderr, "SSL 3.0");
 275                         break;
 276                 case BR_TLS10:
 277                         fprintf(stderr, "TLS 1.0");
 278                         break;
 279                 case BR_TLS11:
 280                         fprintf(stderr, "TLS 1.1");
 281                         break;
 282                 case BR_TLS12:
 283                         fprintf(stderr, "TLS 1.2");
 284                         break;
 285                 default:
 286                         fprintf(stderr, "unknown (0x%04X)",
 287                                 (unsigned)cc->client_max_version);
 288                         break;
 289                 }
 290                 fprintf(stderr, "\n");
 291                 fprintf(stderr, "   Compatible cipher suites:\n");
 292                 for (u = 0; u < st_num; u ++) {
 293                         char csn[80];
 294
 295                         get_suite_name_ext(st[u][0], csn, sizeof csn);
 296                         fprintf(stderr, "      %s\n", csn);
 297                 }
 298                 fprintf(stderr, "   Common hash functions:");
 299                 for (u = 2; u <= 6; u ++) {
 300                         if ((chashes >> u) & 1) {
 301                                 int z;
 302
 303                                 switch (u) {
 304                                 case 3: z = 224; break;
 305                                 case 4: z = 256; break;
 306                                 case 5: z = 384; break;
 307                                 case 6: z = 512; break;
 308                                 default:
 309                                         z = 1;
 310                                         break;
 311                                 }
 312                                 fprintf(stderr, " sha%d", z);
 313                         }
 314                 }
 315                 fprintf(stderr, "\n");
 316         }
 317         for (u = 0; u < st_num; u ++) {
 318                 unsigned tt;
 319
 320                 tt = st[u][1];
 321                 switch (tt >> 12) {
 322                 case BR_SSLKEYX_RSA:
 323                         if (pc->sk->key_type == BR_KEYTYPE_RSA) {
 324                                 choices->cipher_suite = st[u][0];
 325                                 goto choose_ok;
 326                         }
 327                         break;
 328                 case BR_SSLKEYX_ECDHE_RSA:
 329                         if (pc->sk->key_type == BR_KEYTYPE_RSA) {
 330                                 choices->cipher_suite = st[u][0];
 331                                 choices->hash_id = hash_id;
 332                                 goto choose_ok;
 333                         }
 334                         break;
 335                 case BR_SSLKEYX_ECDHE_ECDSA:
 336                         if (pc->sk->key_type == BR_KEYTYPE_EC) {
 337                                 choices->cipher_suite = st[u][0];
 338                                 choices->hash_id = hash_id;
 339                                 goto choose_ok;
 340                         }
 341                         break;
 342                 case BR_SSLKEYX_ECDH_RSA:
 343                         if (pc->sk->key_type == BR_KEYTYPE_EC
 344                                 && pc->cert_signer_algo == BR_KEYTYPE_RSA)
 345                         {
 346                                 choices->cipher_suite = st[u][0];
 347                                 goto choose_ok;
 348                         }
 349                         break;
 350                 case BR_SSLKEYX_ECDH_ECDSA:
 351                         if (pc->sk->key_type == BR_KEYTYPE_EC
 352                                 && pc->cert_signer_algo == BR_KEYTYPE_EC)
 353                         {
 354                                 choices->cipher_suite = st[u][0];
 355                                 goto choose_ok;
 356                         }
 357                         break;
 358                 }
 359         }
 360         return 0;
 361
 362 choose_ok:
 363         choices->chain = pc->chain;
 364         choices->chain_len = pc->chain_len;
 365         if (pc->verbose) {
 366                 char csn[80];
 367
 368                 get_suite_name_ext(choices->cipher_suite, csn, sizeof csn);
 369                 fprintf(stderr, "Using: %s\n", csn);
 370         }
 371         return 1;
 372 }
 373
 374 static uint32_t
 375 sp_do_keyx(const br_ssl_server_policy_class **pctx,
 376         unsigned char *data, size_t len)
 377 {
 378         policy_context *pc;
 379
 380         pc = (policy_context *)pctx;
 381         switch (pc->sk->key_type) {
 382         case BR_KEYTYPE_RSA:
 383                 return br_rsa_ssl_decrypt(
 384                         &br_rsa_i31_private, &pc->sk->key.rsa,
 385                         data, len);
 386         case BR_KEYTYPE_EC:
 387                 return br_ec_prime_i31.mul(data, len, pc->sk->key.ec.x,
 388                         pc->sk->key.ec.xlen, pc->sk->key.ec.curve);
 389         default:
 390                 fprintf(stderr, "ERROR: unknown private key type (%d)\n",
 391                         (int)pc->sk->key_type);
 392                 return 0;
 393         }
 394 }
 395
 396 /*
 397  * OID for hash functions in RSA signatures.
 398  */
 399 static const unsigned char HASH_OID_SHA1[] = {
 400         0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A
 401 };
 402
 403 static const unsigned char HASH_OID_SHA224[] = {
 404         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04
 405 };
 406
 407 static const unsigned char HASH_OID_SHA256[] = {
 408         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01
 409 };
 410
 411 static const unsigned char HASH_OID_SHA384[] = {
 412         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02
 413 };
 414
 415 static const unsigned char HASH_OID_SHA512[] = {
 416         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03
 417 };
 418
 419 static const unsigned char *HASH_OID[] = {
 420         HASH_OID_SHA1,
 421         HASH_OID_SHA224,
 422         HASH_OID_SHA256,
 423         HASH_OID_SHA384,
 424         HASH_OID_SHA512
 425 };
 426
 427 static const br_hash_class *
 428 get_hash_impl(int hash_id)
 429 {
 430         size_t u;
 431
 432         for (u = 0; hash_functions[u].name; u ++) {
 433                 const br_hash_class *hc;
 434                 int id;
 435
 436                 hc = hash_functions[u].hclass;
 437                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 438                 if (id == hash_id) {
 439                         return hc;
 440                 }
 441         }
 442         return NULL;
 443 }
 444
 445 static size_t
 446 sp_do_sign(const br_ssl_server_policy_class **pctx,
 447         int hash_id, size_t hv_len, unsigned char *data, size_t len)
 448 {
 449         policy_context *pc;
 450         unsigned char hv[64];
 451
 452         pc = (policy_context *)pctx;
 453         memcpy(hv, data, hv_len);
 454         switch (pc->sk->key_type) {
 455                 size_t sig_len;
 456                 uint32_t x;
 457                 const unsigned char *hash_oid;
 458                 const br_hash_class *hc;
 459
 460         case BR_KEYTYPE_RSA:
 461                 if (hash_id == 0) {
 462                         hash_oid = NULL;
 463                 } else if (hash_id >= 2 && hash_id <= 6) {
 464                         hash_oid = HASH_OID[hash_id - 2];
 465                 } else {
 466                         if (pc->verbose) {
 467                                 fprintf(stderr, "ERROR: cannot RSA-sign with"
 468                                         " unknown hash function: %d\n",
 469                                         hash_id);
 470                         }
 471                         return 0;
 472                 }
 473                 sig_len = (pc->sk->key.rsa.n_bitlen + 7) >> 3;
 474                 if (len < sig_len) {
 475                         if (pc->verbose) {
 476                                 fprintf(stderr, "ERROR: cannot RSA-sign,"
 477                                         " buffer is too small"
 478                                         " (sig=%lu, buf=%lu)\n",
 479                                         (unsigned long)sig_len,
 480                                         (unsigned long)len);
 481                         }
 482                         return 0;
 483                 }
 484                 x = br_rsa_i31_pkcs1_sign(hash_oid, hv, hv_len,
 485                         &pc->sk->key.rsa, data);
 486                 if (!x) {
 487                         if (pc->verbose) {
 488                                 fprintf(stderr, "ERROR: RSA-sign failure\n");
 489                         }
 490                         return 0;
 491                 }
 492                 return sig_len;
 493
 494         case BR_KEYTYPE_EC:
 495                 hc = get_hash_impl(hash_id);
 496                 if (hc == NULL) {
 497                         if (pc->verbose) {
 498                                 fprintf(stderr, "ERROR: cannot RSA-sign with"
 499                                         " unknown hash function: %d\n",
 500                                         hash_id);
 501                         }
 502                         return 0;
 503                 }
 504                 if (len < 139) {
 505                         if (pc->verbose) {
 506                                 fprintf(stderr, "ERROR: cannot ECDSA-sign"
 507                                         " (output buffer = %lu)\n",
 508                                         (unsigned long)len);
 509                         }
 510                         return 0;
 511                 }
 512                 sig_len = br_ecdsa_i31_sign_asn1(&br_ec_prime_i31,
 513                         hc, hv, &pc->sk->key.ec, data);
 514                 if (sig_len == 0) {
 515                         if (pc->verbose) {
 516                                 fprintf(stderr, "ERROR: ECDSA-sign failure\n");
 517                         }
 518                         return 0;
 519                 }
 520                 return sig_len;
 521
 522         default:
 523                 return 0;
 524         }
 525 }
 526
 527 static const br_ssl_server_policy_class policy_vtable = {
 528         sizeof(policy_context),
 529         sp_choose,
 530         sp_do_keyx,
 531         sp_do_sign
 532 };
 533
 534 /* see brssl.h */
 535 int
 536 do_server(int argc, char *argv[])
 537 {
 538         int retcode;
 539         int verbose;
 540         int trace;
 541         int i, bidi;
 542         const char *bind_name;
 543         const char *port;
 544         unsigned vmin, vmax;
 545         cipher_suite *suites;
 546         size_t num_suites;
 547         uint16_t *suite_ids;
 548         unsigned hfuns;
 549         br_x509_certificate *chain;
 550         size_t chain_len;
 551         int cert_signer_algo;
 552         private_key *sk;
 553         size_t u;
 554         br_ssl_server_context cc;
 555         policy_context pc;
 556         br_ssl_session_cache_lru lru;
 557         unsigned char *iobuf, *cache;
 558         size_t iobuf_len, cache_len;
 559         uint32_t flags;
 560         int server_fd, fd;
 561
 562         retcode = 0;
 563         verbose = 1;
 564         trace = 0;
 565         bind_name = NULL;
 566         port = NULL;
 567         bidi = 1;
 568         vmin = 0;
 569         vmax = 0;
 570         suites = NULL;
 571         num_suites = 0;
 572         hfuns = 0;
 573         suite_ids = NULL;
 574         chain = NULL;
 575         chain_len = 0;
 576         sk = NULL;
 577         iobuf = NULL;
 578         iobuf_len = 0;
 579         cache = NULL;
 580         cache_len = (size_t)-1;
 581         flags = 0;
 582         server_fd = -1;
 583         fd = -1;
 584         for (i = 0; i < argc; i ++) {
 585                 const char *arg;
 586
 587                 arg = argv[i];
 588                 if (arg[0] != '-') {
 589                         usage_server();
 590                         goto server_exit_error;
 591                 }
 592                 if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
 593                         verbose = 1;
 594                 } else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
 595                         verbose = 0;
 596                 } else if (eqstr(arg, "-trace")) {
 597                         trace = 1;
 598                 } else if (eqstr(arg, "-b")) {
 599                         if (++ i >= argc) {
 600                                 fprintf(stderr,
 601                                         "ERROR: no argument for '-b'\n");
 602                                 usage_server();
 603                                 goto server_exit_error;
 604                         }
 605                         if (bind_name != NULL) {
 606                                 fprintf(stderr, "ERROR: duplicate bind host\n");
 607                                 usage_server();
 608                                 goto server_exit_error;
 609                         }
 610                         bind_name = argv[i];
 611                 } else if (eqstr(arg, "-p")) {
 612                         if (++ i >= argc) {
 613                                 fprintf(stderr,
 614                                         "ERROR: no argument for '-p'\n");
 615                                 usage_server();
 616                                 goto server_exit_error;
 617                         }
 618                         if (port != NULL) {
 619                                 fprintf(stderr, "ERROR: duplicate bind port\n");
 620                                 usage_server();
 621                                 goto server_exit_error;
 622                         }
 623                         port = argv[i];
 624                 } else if (eqstr(arg, "-mono")) {
 625                         bidi = 0;
 626                 } else if (eqstr(arg, "-buf")) {
 627                         if (++ i >= argc) {
 628                                 fprintf(stderr,
 629                                         "ERROR: no argument for '-buf'\n");
 630                                 usage_server();
 631                                 goto server_exit_error;
 632                         }
 633                         arg = argv[i];
 634                         if (iobuf_len != 0) {
 635                                 fprintf(stderr,
 636                                         "ERROR: duplicate I/O buffer length\n");
 637                                 usage_server();
 638                                 goto server_exit_error;
 639                         }
 640                         iobuf_len = parse_size(arg);
 641                         if (iobuf_len == (size_t)-1) {
 642                                 usage_server();
 643                                 goto server_exit_error;
 644                         }
 645                 } else if (eqstr(arg, "-cache")) {
 646                         if (++ i >= argc) {
 647                                 fprintf(stderr,
 648                                         "ERROR: no argument for '-cache'\n");
 649                                 usage_server();
 650                                 goto server_exit_error;
 651                         }
 652                         arg = argv[i];
 653                         if (cache_len != (size_t)-1) {
 654                                 fprintf(stderr, "ERROR: duplicate session"
 655                                         " cache length\n");
 656                                 usage_server();
 657                                 goto server_exit_error;
 658                         }
 659                         cache_len = parse_size(arg);
 660                         if (cache_len == (size_t)-1) {
 661                                 usage_server();
 662                                 goto server_exit_error;
 663                         }
 664                 } else if (eqstr(arg, "-cert")) {
 665                         if (++ i >= argc) {
 666                                 fprintf(stderr,
 667                                         "ERROR: no argument for '-cert'\n");
 668                                 usage_server();
 669                                 goto server_exit_error;
 670                         }
 671                         if (chain != NULL) {
 672                                 fprintf(stderr,
 673                                         "ERROR: duplicate certificate chain\n");
 674                                 usage_server();
 675                                 goto server_exit_error;
 676                         }
 677                         arg = argv[i];
 678                         chain = read_certificates(arg, &chain_len);
 679                         if (chain == NULL || chain_len == 0) {
 680                                 goto server_exit_error;
 681                         }
 682                 } else if (eqstr(arg, "-key")) {
 683                         if (++ i >= argc) {
 684                                 fprintf(stderr,
 685                                         "ERROR: no argument for '-key'\n");
 686                                 usage_server();
 687                                 goto server_exit_error;
 688                         }
 689                         if (sk != NULL) {
 690                                 fprintf(stderr,
 691                                         "ERROR: duplicate private key\n");
 692                                 usage_server();
 693                                 goto server_exit_error;
 694                         }
 695                         arg = argv[i];
 696                         sk = read_private_key(arg);
 697                         if (sk == NULL) {
 698                                 goto server_exit_error;
 699                         }
 700                 } else if (eqstr(arg, "-list")) {
 701                         list_names();
 702                         goto server_exit;
 703                 } else if (eqstr(arg, "-vmin")) {
 704                         if (++ i >= argc) {
 705                                 fprintf(stderr,
 706                                         "ERROR: no argument for '-vmin'\n");
 707                                 usage_server();
 708                                 goto server_exit_error;
 709                         }
 710                         arg = argv[i];
 711                         if (vmin != 0) {
 712                                 fprintf(stderr,
 713                                         "ERROR: duplicate minimum version\n");
 714                                 usage_server();
 715                                 goto server_exit_error;
 716                         }
 717                         vmin = parse_version(arg, strlen(arg));
 718                         if (vmin == 0) {
 719                                 fprintf(stderr,
 720                                         "ERROR: unrecognised version '%s'\n",
 721                                         arg);
 722                                 usage_server();
 723                                 goto server_exit_error;
 724                         }
 725                 } else if (eqstr(arg, "-vmax")) {
 726                         if (++ i >= argc) {
 727                                 fprintf(stderr,
 728                                         "ERROR: no argument for '-vmax'\n");
 729                                 usage_server();
 730                                 goto server_exit_error;
 731                         }
 732                         arg = argv[i];
 733                         if (vmax != 0) {
 734                                 fprintf(stderr,
 735                                         "ERROR: duplicate maximum version\n");
 736                                 usage_server();
 737                                 goto server_exit_error;
 738                         }
 739                         vmax = parse_version(arg, strlen(arg));
 740                         if (vmax == 0) {
 741                                 fprintf(stderr,
 742                                         "ERROR: unrecognised version '%s'\n",
 743                                         arg);
 744                                 usage_server();
 745                                 goto server_exit_error;
 746                         }
 747                 } else if (eqstr(arg, "-cs")) {
 748                         if (++ i >= argc) {
 749                                 fprintf(stderr,
 750                                         "ERROR: no argument for '-cs'\n");
 751                                 usage_server();
 752                                 goto server_exit_error;
 753                         }
 754                         arg = argv[i];
 755                         if (suites != NULL) {
 756                                 fprintf(stderr, "ERROR: duplicate list"
 757                                         " of cipher suites\n");
 758                                 usage_server();
 759                                 goto server_exit_error;
 760                         }
 761                         suites = parse_suites(arg, &num_suites);
 762                         if (suites == NULL) {
 763                                 usage_server();
 764                                 goto server_exit_error;
 765                         }
 766                 } else if (eqstr(arg, "-hf")) {
 767                         unsigned x;
 768
 769                         if (++ i >= argc) {
 770                                 fprintf(stderr,
 771                                         "ERROR: no argument for '-hf'\n");
 772                                 usage_server();
 773                                 goto server_exit_error;
 774                         }
 775                         arg = argv[i];
 776                         x = parse_hash_functions(arg);
 777                         if (x == 0) {
 778                                 usage_server();
 779                                 goto server_exit_error;
 780                         }
 781                         hfuns |= x;
 782                 } else if (eqstr(arg, "-serverpref")) {
 783                         flags |= BR_OPT_ENFORCE_SERVER_PREFERENCES;
 784                 } else {
 785                         fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
 786                         usage_server();
 787                         goto server_exit_error;
 788                 }
 789         }
 790         if (port == NULL) {
 791                 port = "4433";
 792         }
 793         if (vmin == 0) {
 794                 vmin = BR_TLS10;
 795         }
 796         if (vmax == 0) {
 797                 vmax = BR_TLS12;
 798         }
 799         if (vmax < vmin) {
 800                 fprintf(stderr, "ERROR: impossible minimum/maximum protocol"
 801                         " version combination\n");
 802                 usage_server();
 803                 goto server_exit_error;
 804         }
 805         if (suites == NULL) {
 806                 num_suites = 0;
 807
 808                 for (u = 0; cipher_suites[u].name; u ++) {
 809                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 810                                 || vmax >= BR_TLS12)
 811                         {
 812                                 num_suites ++;
 813                         }
 814                 }
 815                 suites = xmalloc(num_suites * sizeof *suites);
 816                 num_suites = 0;
 817                 for (u = 0; cipher_suites[u].name; u ++) {
 818                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 819                                 || vmax >= BR_TLS12)
 820                         {
 821                                 suites[num_suites ++] = cipher_suites[u];
 822                         }
 823                 }
 824         }
 825         if (hfuns == 0) {
 826                 hfuns = (unsigned)-1;
 827         }
 828         if (chain == NULL || chain_len == 0) {
 829                 fprintf(stderr, "ERROR: no certificate chain provided\n");
 830                 goto server_exit_error;
 831         }
 832         if (sk == NULL) {
 833                 fprintf(stderr, "ERROR: no private key provided\n");
 834                 goto server_exit_error;
 835         }
 836         switch (sk->key_type) {
 837                 int curve;
 838                 uint32_t supp;
 839
 840         case BR_KEYTYPE_RSA:
 841                 break;
 842         case BR_KEYTYPE_EC:
 843                 curve = sk->key.ec.curve;
 844                 supp = br_ec_prime_i31.supported_curves;
 845                 if (curve > 31 || !((supp >> curve) & 1)) {
 846                         fprintf(stderr, "ERROR: private key curve (%d)"
 847                                 " is not supported\n", curve);
 848                         goto server_exit_error;
 849                 }
 850                 break;
 851         default:
 852                 fprintf(stderr, "ERROR: unsupported private key type (%d)\n",
 853                         sk->key_type);
 854                 break;
 855         }
 856         cert_signer_algo = get_cert_signer_algo(chain);
 857         if (cert_signer_algo < 0) {
 858                 fprintf(stderr, "ERROR: server certificate cannot be"
 859                         " decoded (err=%d)\n", -cert_signer_algo);
 860                 goto server_exit_error;
 861         } else if (verbose) {
 862                 const char *csas;
 863
 864                 switch (cert_signer_algo) {
 865                 case BR_KEYTYPE_RSA: csas = "RSA"; break;
 866                 case BR_KEYTYPE_EC:  csas = "EC"; break;
 867                 default:
 868                         csas = "unknown";
 869                         break;
 870                 }
 871                 fprintf(stderr, "Issuing CA key type: %d (%s)\n",
 872                         cert_signer_algo, csas);
 873         }
 874         if (iobuf_len == 0) {
 875                 if (bidi) {
 876                         iobuf_len = BR_SSL_BUFSIZE_BIDI;
 877                 } else {
 878                         iobuf_len = BR_SSL_BUFSIZE_MONO;
 879                 }
 880         }
 881         iobuf = xmalloc(iobuf_len);
 882         if (cache_len == (size_t)-1) {
 883                 cache_len = 5000;
 884         }
 885         cache = xmalloc(cache_len);
 886
 887         /*
 888          * Compute implementation requirements and inject implementations.
 889          */
 890         suite_ids = xmalloc(num_suites * sizeof *suite_ids);
 891         br_ssl_server_zero(&cc);
 892         br_ssl_engine_set_versions(&cc.eng, vmin, vmax);
 893         br_ssl_server_set_all_flags(&cc, flags);
 894         if (vmin <= BR_TLS11) {
 895                 if (!(hfuns & (1 << br_md5_ID))) {
 896                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need MD5\n");
 897                         goto server_exit_error;
 898                 }
 899                 if (!(hfuns & (1 << br_sha1_ID))) {
 900                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need SHA-1\n");
 901                         goto server_exit_error;
 902                 }
 903         }
 904         for (u = 0; u < num_suites; u ++) {
 905                 unsigned req;
 906
 907                 req = suites[u].req;
 908                 suite_ids[u] = suites[u].suite;
 909                 if ((req & REQ_TLS12) != 0 && vmax < BR_TLS12) {
 910                         fprintf(stderr,
 911                                 "ERROR: cipher suite %s requires TLS 1.2\n",
 912                                 suites[u].name);
 913                         goto server_exit_error;
 914                 }
 915                 if ((req & REQ_SHA1) != 0 && !(hfuns & (1 << br_sha1_ID))) {
 916                         fprintf(stderr,
 917                                 "ERROR: cipher suite %s requires SHA-1\n",
 918                                 suites[u].name);
 919                         goto server_exit_error;
 920                 }
 921                 if ((req & REQ_SHA256) != 0 && !(hfuns & (1 << br_sha256_ID))) {
 922                         fprintf(stderr,
 923                                 "ERROR: cipher suite %s requires SHA-256\n",
 924                                 suites[u].name);
 925                         goto server_exit_error;
 926                 }
 927                 if ((req & REQ_SHA384) != 0 && !(hfuns & (1 << br_sha384_ID))) {
 928                         fprintf(stderr,
 929                                 "ERROR: cipher suite %s requires SHA-384\n",
 930                                 suites[u].name);
 931                         goto server_exit_error;
 932                 }
 933                 /* TODO: algorithm implementation selection */
 934                 if ((req & REQ_AESCBC) != 0) {
 935                         br_ssl_engine_set_aes_cbc(&cc.eng,
 936                                 &br_aes_ct_cbcenc_vtable,
 937                                 &br_aes_ct_cbcdec_vtable);
 938                         br_ssl_engine_set_cbc(&cc.eng,
 939                                 &br_sslrec_in_cbc_vtable,
 940                                 &br_sslrec_out_cbc_vtable);
 941                 }
 942                 if ((req & REQ_AESGCM) != 0) {
 943                         br_ssl_engine_set_aes_ctr(&cc.eng,
 944                                 &br_aes_ct_ctr_vtable);
 945                         br_ssl_engine_set_ghash(&cc.eng,
 946                                 &br_ghash_ctmul);
 947                         br_ssl_engine_set_gcm(&cc.eng,
 948                                 &br_sslrec_in_gcm_vtable,
 949                                 &br_sslrec_out_gcm_vtable);
 950                 }
 951                 if ((req & REQ_3DESCBC) != 0) {
 952                         br_ssl_engine_set_des_cbc(&cc.eng,
 953                                 &br_des_ct_cbcenc_vtable,
 954                                 &br_des_ct_cbcdec_vtable);
 955                         br_ssl_engine_set_cbc(&cc.eng,
 956                                 &br_sslrec_in_cbc_vtable,
 957                                 &br_sslrec_out_cbc_vtable);
 958                 }
 959                 if ((req & (REQ_ECDHE_RSA | REQ_ECDHE_ECDSA)) != 0) {
 960                         br_ssl_engine_set_ec(&cc.eng, &br_ec_prime_i31);
 961                 }
 962         }
 963         br_ssl_engine_set_suites(&cc.eng, suite_ids, num_suites);
 964
 965         for (u = 0; hash_functions[u].name; u ++) {
 966                 const br_hash_class *hc;
 967                 int id;
 968
 969                 hc = hash_functions[u].hclass;
 970                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 971                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 972                         br_ssl_engine_set_hash(&cc.eng, id, hc);
 973                 }
 974         }
 975         if (vmin <= BR_TLS11) {
 976                 br_ssl_engine_set_prf10(&cc.eng, &br_tls10_prf);
 977         }
 978         if (vmax >= BR_TLS12) {
 979                 if ((hfuns & ((unsigned)1 << br_sha256_ID)) != 0) {
 980                         br_ssl_engine_set_prf_sha256(&cc.eng,
 981                                 &br_tls12_sha256_prf);
 982                 }
 983                 if ((hfuns & ((unsigned)1 << br_sha384_ID)) != 0) {
 984                         br_ssl_engine_set_prf_sha384(&cc.eng,
 985                                 &br_tls12_sha384_prf);
 986                 }
 987         }
 988
 989         br_ssl_session_cache_lru_init(&lru, cache, cache_len);
 990         br_ssl_server_set_cache(&cc, &lru.vtable);
 991
 992         pc.vtable = &policy_vtable;
 993         pc.verbose = verbose;
 994         pc.chain = chain;
 995         pc.chain_len = chain_len;
 996         pc.cert_signer_algo = cert_signer_algo;
 997         pc.sk = sk;
 998         br_ssl_server_set_policy(&cc, &pc.vtable);
 999
1000         br_ssl_engine_set_buffer(&cc.eng, iobuf, iobuf_len, bidi);
1001
1002         /*
1003          * Open the server socket.
1004          */
1005         server_fd = host_bind(bind_name, port, verbose);
1006         if (server_fd < 0) {
1007                 goto server_exit_error;
1008         }
1009
1010         /*
1011          * Process incoming clients, one at a time. Note that we do not
1012          * accept any client until the previous connection has finished:
1013          * this is voluntary, since the tool uses stdin/stdout for
1014          * application data, and thus cannot really run two connections
1015          * simultaneously.
1016          */
1017         for (;;) {
1018                 int x;
1019
1020                 fd = accept_client(server_fd, verbose);
1021                 if (fd < 0) {
1022                         goto server_exit_error;
1023                 }
1024                 br_ssl_server_reset(&cc);
1025                 x = run_ssl_engine(&cc.eng, fd,
1026                         (verbose ? RUN_ENGINE_VERBOSE : 0)
1027                         | (trace ? RUN_ENGINE_TRACE : 0));
1028                 close(fd);
1029                 fd = -1;
1030                 if (x < -1) {
1031                         goto server_exit_error;
1032                 }
1033         }
1034
1035         /*
1036          * Release allocated structures.
1037          */
1038 server_exit:
1039         xfree(suites);
1040         xfree(suite_ids);
1041         if (chain != NULL) {
1042                 for (u = 0; u < chain_len; u ++) {
1043                         xfree(chain[u].data);
1044                 }
1045                 xfree(chain);
1046         }
1047         free_private_key(sk);
1048         xfree(iobuf);
1049         xfree(cache);
1050         if (fd >= 0) {
1051                 close(fd);
1052         }
1053         return retcode;
1054
1055 server_exit_error:
1056         retcode = -1;
1057         goto server_exit;
1058 }