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