_ 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 #include <signal.h>
  31
  32 #include <sys/types.h>
  33 #include <sys/socket.h>
  34 #include <netdb.h>
  35 #include <netinet/in.h>
  36 #include <arpa/inet.h>
  37 #include <unistd.h>
  38 #include <fcntl.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                 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 (verbose) {
  90                         char tmp[INET6_ADDRSTRLEN + 50];
  91
  92                         if (addr != NULL) {
  93                                 if (!inet_ntop(p->ai_family, addr,
  94                                         tmp, sizeof tmp))
  95                                 {
  96                                         strcpy(tmp, "<invalid>");
  97                                 }
  98                         } else {
  99                                 sprintf(tmp, "<unknown family: %d>",
 100                                         (int)sa->sa_family);
 101                         }
 102                         fprintf(stderr, "binding to: %s\n", tmp);
 103                 }
 104                 fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
 105                 if (fd < 0) {
 106                         if (verbose) {
 107                                 perror("socket()");
 108                         }
 109                         continue;
 110                 }
 111                 opt = 1;
 112                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof opt);
 113                 opt = 0;
 114                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof opt);
 115                 if (bind(fd, sa, sa_len) < 0) {
 116                         if (verbose) {
 117                                 perror("bind()");
 118                         }
 119                         close(fd);
 120                         continue;
 121                 }
 122                 break;
 123         }
 124         if (p == NULL) {
 125                 freeaddrinfo(si);
 126                 fprintf(stderr, "ERROR: failed to bind\n");
 127                 return -1;
 128         }
 129         freeaddrinfo(si);
 130         if (listen(fd, 5) < 0) {
 131                 if (verbose) {
 132                         perror("listen()");
 133                 }
 134                 close(fd);
 135                 return -1;
 136         }
 137         if (verbose) {
 138                 fprintf(stderr, "bound.\n");
 139         }
 140         return fd;
 141 }
 142
 143 static int
 144 accept_client(int server_fd, int verbose)
 145 {
 146         int fd;
 147         struct sockaddr sa;
 148         socklen_t sa_len;
 149
 150         sa_len = sizeof sa;
 151         fd = accept(server_fd, &sa, &sa_len);
 152         if (fd < 0) {
 153                 if (verbose) {
 154                         perror("accept()");
 155                 }
 156                 return -1;
 157         }
 158         if (verbose) {
 159                 char tmp[INET6_ADDRSTRLEN + 50];
 160                 const char *name;
 161
 162                 name = NULL;
 163                 switch (sa.sa_family) {
 164                 case AF_INET:
 165                         name = inet_ntop(AF_INET,
 166                                 &((struct sockaddr_in *)&sa)->sin_addr,
 167                                 tmp, sizeof tmp);
 168                         break;
 169                 case AF_INET6:
 170                         name = inet_ntop(AF_INET6,
 171                                 &((struct sockaddr_in6 *)&sa)->sin6_addr,
 172                                 tmp, sizeof tmp);
 173                         break;
 174                 }
 175                 if (name == NULL) {
 176                         sprintf(tmp, "<unknown: %lu>",
 177                                 (unsigned long)sa.sa_family);
 178                         name = tmp;
 179                 }
 180                 fprintf(stderr, "accepting connection from: %s\n", name);
 181         }
 182
 183         /*
 184          * We make the socket non-blocking, since we are going to use
 185          * poll() to organise I/O.
 186          */
 187         fcntl(fd, F_SETFL, O_NONBLOCK);
 188         return fd;
 189 }
 190
 191 static void
 192 usage_server(void)
 193 {
 194         fprintf(stderr,
 195 "usage: brssl server [ options ]\n");
 196         fprintf(stderr,
 197 "options:\n");
 198         fprintf(stderr,
 199 "   -q              suppress verbose messages\n");
 200         fprintf(stderr,
 201 "   -trace          activate extra debug messages (dump of all packets)\n");
 202         fprintf(stderr,
 203 "   -b name         bind to a specific address or host name\n");
 204         fprintf(stderr,
 205 "   -p port         bind to a specific port (default: 4433)\n");
 206         fprintf(stderr,
 207 "   -mono           use monodirectional buffering\n");
 208         fprintf(stderr,
 209 "   -buf length     set the I/O buffer length (in bytes)\n");
 210         fprintf(stderr,
 211 "   -cache length   set the session cache storage length (in bytes)\n");
 212         fprintf(stderr,
 213 "   -cert fname     read certificate chain from file 'fname'\n");
 214         fprintf(stderr,
 215 "   -key fname      read private key from file 'fname'\n");
 216         fprintf(stderr,
 217 "   -list           list supported names (protocols, algorithms...)\n");
 218         fprintf(stderr,
 219 "   -vmin name      set minimum supported version (default: TLS-1.0)\n");
 220         fprintf(stderr,
 221 "   -vmax name      set maximum supported version (default: TLS-1.2)\n");
 222         fprintf(stderr,
 223 "   -cs names       set list of supported cipher suites (comma-separated)\n");
 224         fprintf(stderr,
 225 "   -hf names       add support for some hash functions (comma-separated)\n");
 226         fprintf(stderr,
 227 "   -serverpref     enforce server's preferences for cipher suites\n");
 228         exit(EXIT_FAILURE);
 229 }
 230
 231 typedef struct {
 232         const br_ssl_server_policy_class *vtable;
 233         int verbose;
 234         br_x509_certificate *chain;
 235         size_t chain_len;
 236         int cert_signer_algo;
 237         private_key *sk;
 238 } policy_context;
 239
 240 static int
 241 get_cert_signer_algo(br_x509_certificate *xc)
 242 {
 243         br_x509_decoder_context dc;
 244         int err;
 245
 246         br_x509_decoder_init(&dc, 0, 0);
 247         br_x509_decoder_push(&dc, xc->data, xc->data_len);
 248         err = br_x509_decoder_last_error(&dc);
 249         if (err != 0) {
 250                 return -err;
 251         } else {
 252                 return br_x509_decoder_get_signer_key_type(&dc);
 253         }
 254 }
 255
 256 static int
 257 sp_choose(const br_ssl_server_policy_class **pctx,
 258         const br_ssl_server_context *cc,
 259         br_ssl_server_choices *choices)
 260 {
 261         policy_context *pc;
 262         const br_suite_translated *st;
 263         size_t u, st_num;
 264         unsigned chashes;
 265         int hash_id;
 266
 267         pc = (policy_context *)pctx;
 268         st = br_ssl_server_get_client_suites(cc, &st_num);
 269         chashes = br_ssl_server_get_client_hashes(cc);
 270         for (hash_id = 6; hash_id >= 2; hash_id --) {
 271                 if ((chashes >> hash_id) & 1) {
 272                         break;
 273                 }
 274         }
 275         if (pc->verbose) {
 276                 fprintf(stderr, "Client parameters:\n");
 277                 fprintf(stderr, "   Maximum version:      ");
 278                 switch (cc->client_max_version) {
 279                 case BR_SSL30:
 280                         fprintf(stderr, "SSL 3.0");
 281                         break;
 282                 case BR_TLS10:
 283                         fprintf(stderr, "TLS 1.0");
 284                         break;
 285                 case BR_TLS11:
 286                         fprintf(stderr, "TLS 1.1");
 287                         break;
 288                 case BR_TLS12:
 289                         fprintf(stderr, "TLS 1.2");
 290                         break;
 291                 default:
 292                         fprintf(stderr, "unknown (0x%04X)",
 293                                 (unsigned)cc->client_max_version);
 294                         break;
 295                 }
 296                 fprintf(stderr, "\n");
 297                 fprintf(stderr, "   Compatible cipher suites:\n");
 298                 for (u = 0; u < st_num; u ++) {
 299                         char csn[80];
 300
 301                         get_suite_name_ext(st[u][0], csn, sizeof csn);
 302                         fprintf(stderr, "      %s\n", csn);
 303                 }
 304                 fprintf(stderr, "   Common hash functions:");
 305                 for (u = 2; u <= 6; u ++) {
 306                         if ((chashes >> u) & 1) {
 307                                 int z;
 308
 309                                 switch (u) {
 310                                 case 3: z = 224; break;
 311                                 case 4: z = 256; break;
 312                                 case 5: z = 384; break;
 313                                 case 6: z = 512; break;
 314                                 default:
 315                                         z = 1;
 316                                         break;
 317                                 }
 318                                 fprintf(stderr, " sha%d", z);
 319                         }
 320                 }
 321                 fprintf(stderr, "\n");
 322         }
 323         for (u = 0; u < st_num; u ++) {
 324                 unsigned tt;
 325
 326                 tt = st[u][1];
 327                 switch (tt >> 12) {
 328                 case BR_SSLKEYX_RSA:
 329                         if (pc->sk->key_type == BR_KEYTYPE_RSA) {
 330                                 choices->cipher_suite = st[u][0];
 331                                 goto choose_ok;
 332                         }
 333                         break;
 334                 case BR_SSLKEYX_ECDHE_RSA:
 335                         if (pc->sk->key_type == BR_KEYTYPE_RSA) {
 336                                 choices->cipher_suite = st[u][0];
 337                                 if (br_ssl_engine_get_version(&cc->eng)
 338                                         < BR_TLS12)
 339                                 {
 340                                         hash_id = 0;
 341                                 }
 342                                 choices->hash_id = hash_id;
 343                                 goto choose_ok;
 344                         }
 345                         break;
 346                 case BR_SSLKEYX_ECDHE_ECDSA:
 347                         if (pc->sk->key_type == BR_KEYTYPE_EC) {
 348                                 choices->cipher_suite = st[u][0];
 349                                 if (br_ssl_engine_get_version(&cc->eng)
 350                                         < BR_TLS12)
 351                                 {
 352                                         hash_id = br_sha1_ID;
 353                                 }
 354                                 choices->hash_id = hash_id;
 355                                 goto choose_ok;
 356                         }
 357                         break;
 358                 case BR_SSLKEYX_ECDH_RSA:
 359                         if (pc->sk->key_type == BR_KEYTYPE_EC
 360                                 && pc->cert_signer_algo == BR_KEYTYPE_RSA)
 361                         {
 362                                 choices->cipher_suite = st[u][0];
 363                                 goto choose_ok;
 364                         }
 365                         break;
 366                 case BR_SSLKEYX_ECDH_ECDSA:
 367                         if (pc->sk->key_type == BR_KEYTYPE_EC
 368                                 && pc->cert_signer_algo == BR_KEYTYPE_EC)
 369                         {
 370                                 choices->cipher_suite = st[u][0];
 371                                 goto choose_ok;
 372                         }
 373                         break;
 374                 }
 375         }
 376         return 0;
 377
 378 choose_ok:
 379         choices->chain = pc->chain;
 380         choices->chain_len = pc->chain_len;
 381         if (pc->verbose) {
 382                 char csn[80];
 383
 384                 get_suite_name_ext(choices->cipher_suite, csn, sizeof csn);
 385                 fprintf(stderr, "Using: %s\n", csn);
 386         }
 387         return 1;
 388 }
 389
 390 static uint32_t
 391 sp_do_keyx(const br_ssl_server_policy_class **pctx,
 392         unsigned char *data, size_t len)
 393 {
 394         policy_context *pc;
 395
 396         pc = (policy_context *)pctx;
 397         switch (pc->sk->key_type) {
 398         case BR_KEYTYPE_RSA:
 399                 return br_rsa_ssl_decrypt(
 400                         &br_rsa_i31_private, &pc->sk->key.rsa,
 401                         data, len);
 402         case BR_KEYTYPE_EC:
 403                 return br_ec_prime_i31.mul(data, len, pc->sk->key.ec.x,
 404                         pc->sk->key.ec.xlen, pc->sk->key.ec.curve);
 405         default:
 406                 fprintf(stderr, "ERROR: unknown private key type (%d)\n",
 407                         (int)pc->sk->key_type);
 408                 return 0;
 409         }
 410 }
 411
 412 /*
 413  * OID for hash functions in RSA signatures.
 414  */
 415 static const unsigned char HASH_OID_SHA1[] = {
 416         0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A
 417 };
 418
 419 static const unsigned char HASH_OID_SHA224[] = {
 420         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04
 421 };
 422
 423 static const unsigned char HASH_OID_SHA256[] = {
 424         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01
 425 };
 426
 427 static const unsigned char HASH_OID_SHA384[] = {
 428         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02
 429 };
 430
 431 static const unsigned char HASH_OID_SHA512[] = {
 432         0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03
 433 };
 434
 435 static const unsigned char *HASH_OID[] = {
 436         HASH_OID_SHA1,
 437         HASH_OID_SHA224,
 438         HASH_OID_SHA256,
 439         HASH_OID_SHA384,
 440         HASH_OID_SHA512
 441 };
 442
 443 static const br_hash_class *
 444 get_hash_impl(int hash_id)
 445 {
 446         size_t u;
 447
 448         for (u = 0; hash_functions[u].name; u ++) {
 449                 const br_hash_class *hc;
 450                 int id;
 451
 452                 hc = hash_functions[u].hclass;
 453                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 454                 if (id == hash_id) {
 455                         return hc;
 456                 }
 457         }
 458         return NULL;
 459 }
 460
 461 static size_t
 462 sp_do_sign(const br_ssl_server_policy_class **pctx,
 463         int hash_id, size_t hv_len, unsigned char *data, size_t len)
 464 {
 465         policy_context *pc;
 466         unsigned char hv[64];
 467
 468         pc = (policy_context *)pctx;
 469         memcpy(hv, data, hv_len);
 470         switch (pc->sk->key_type) {
 471                 size_t sig_len;
 472                 uint32_t x;
 473                 const unsigned char *hash_oid;
 474                 const br_hash_class *hc;
 475
 476         case BR_KEYTYPE_RSA:
 477                 if (hash_id == 0) {
 478                         hash_oid = NULL;
 479                 } else if (hash_id >= 2 && hash_id <= 6) {
 480                         hash_oid = HASH_OID[hash_id - 2];
 481                 } else {
 482                         if (pc->verbose) {
 483                                 fprintf(stderr, "ERROR: cannot RSA-sign with"
 484                                         " unknown hash function: %d\n",
 485                                         hash_id);
 486                         }
 487                         return 0;
 488                 }
 489                 sig_len = (pc->sk->key.rsa.n_bitlen + 7) >> 3;
 490                 if (len < sig_len) {
 491                         if (pc->verbose) {
 492                                 fprintf(stderr, "ERROR: cannot RSA-sign,"
 493                                         " buffer is too small"
 494                                         " (sig=%lu, buf=%lu)\n",
 495                                         (unsigned long)sig_len,
 496                                         (unsigned long)len);
 497                         }
 498                         return 0;
 499                 }
 500                 x = br_rsa_i31_pkcs1_sign(hash_oid, hv, hv_len,
 501                         &pc->sk->key.rsa, data);
 502                 if (!x) {
 503                         if (pc->verbose) {
 504                                 fprintf(stderr, "ERROR: RSA-sign failure\n");
 505                         }
 506                         return 0;
 507                 }
 508                 return sig_len;
 509
 510         case BR_KEYTYPE_EC:
 511                 hc = get_hash_impl(hash_id);
 512                 if (hc == NULL) {
 513                         if (pc->verbose) {
 514                                 fprintf(stderr, "ERROR: cannot ECDSA-sign with"
 515                                         " unknown hash function: %d\n",
 516                                         hash_id);
 517                         }
 518                         return 0;
 519                 }
 520                 if (len < 139) {
 521                         if (pc->verbose) {
 522                                 fprintf(stderr, "ERROR: cannot ECDSA-sign"
 523                                         " (output buffer = %lu)\n",
 524                                         (unsigned long)len);
 525                         }
 526                         return 0;
 527                 }
 528                 sig_len = br_ecdsa_i31_sign_asn1(&br_ec_prime_i31,
 529                         hc, hv, &pc->sk->key.ec, data);
 530                 if (sig_len == 0) {
 531                         if (pc->verbose) {
 532                                 fprintf(stderr, "ERROR: ECDSA-sign failure\n");
 533                         }
 534                         return 0;
 535                 }
 536                 return sig_len;
 537
 538         default:
 539                 return 0;
 540         }
 541 }
 542
 543 static const br_ssl_server_policy_class policy_vtable = {
 544         sizeof(policy_context),
 545         sp_choose,
 546         sp_do_keyx,
 547         sp_do_sign
 548 };
 549
 550 /* see brssl.h */
 551 int
 552 do_server(int argc, char *argv[])
 553 {
 554         int retcode;
 555         int verbose;
 556         int trace;
 557         int i, bidi;
 558         const char *bind_name;
 559         const char *port;
 560         unsigned vmin, vmax;
 561         cipher_suite *suites;
 562         size_t num_suites;
 563         uint16_t *suite_ids;
 564         unsigned hfuns;
 565         br_x509_certificate *chain;
 566         size_t chain_len;
 567         int cert_signer_algo;
 568         private_key *sk;
 569         size_t u;
 570         br_ssl_server_context cc;
 571         policy_context pc;
 572         br_ssl_session_cache_lru lru;
 573         unsigned char *iobuf, *cache;
 574         size_t iobuf_len, cache_len;
 575         uint32_t flags;
 576         int server_fd, fd;
 577
 578         retcode = 0;
 579         verbose = 1;
 580         trace = 0;
 581         bind_name = NULL;
 582         port = NULL;
 583         bidi = 1;
 584         vmin = 0;
 585         vmax = 0;
 586         suites = NULL;
 587         num_suites = 0;
 588         hfuns = 0;
 589         suite_ids = NULL;
 590         chain = NULL;
 591         chain_len = 0;
 592         sk = NULL;
 593         iobuf = NULL;
 594         iobuf_len = 0;
 595         cache = NULL;
 596         cache_len = (size_t)-1;
 597         flags = 0;
 598         server_fd = -1;
 599         fd = -1;
 600         for (i = 0; i < argc; i ++) {
 601                 const char *arg;
 602
 603                 arg = argv[i];
 604                 if (arg[0] != '-') {
 605                         usage_server();
 606                         goto server_exit_error;
 607                 }
 608                 if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
 609                         verbose = 1;
 610                 } else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
 611                         verbose = 0;
 612                 } else if (eqstr(arg, "-trace")) {
 613                         trace = 1;
 614                 } else if (eqstr(arg, "-b")) {
 615                         if (++ i >= argc) {
 616                                 fprintf(stderr,
 617                                         "ERROR: no argument for '-b'\n");
 618                                 usage_server();
 619                                 goto server_exit_error;
 620                         }
 621                         if (bind_name != NULL) {
 622                                 fprintf(stderr, "ERROR: duplicate bind host\n");
 623                                 usage_server();
 624                                 goto server_exit_error;
 625                         }
 626                         bind_name = argv[i];
 627                 } else if (eqstr(arg, "-p")) {
 628                         if (++ i >= argc) {
 629                                 fprintf(stderr,
 630                                         "ERROR: no argument for '-p'\n");
 631                                 usage_server();
 632                                 goto server_exit_error;
 633                         }
 634                         if (port != NULL) {
 635                                 fprintf(stderr, "ERROR: duplicate bind port\n");
 636                                 usage_server();
 637                                 goto server_exit_error;
 638                         }
 639                         port = argv[i];
 640                 } else if (eqstr(arg, "-mono")) {
 641                         bidi = 0;
 642                 } else if (eqstr(arg, "-buf")) {
 643                         if (++ i >= argc) {
 644                                 fprintf(stderr,
 645                                         "ERROR: no argument for '-buf'\n");
 646                                 usage_server();
 647                                 goto server_exit_error;
 648                         }
 649                         arg = argv[i];
 650                         if (iobuf_len != 0) {
 651                                 fprintf(stderr,
 652                                         "ERROR: duplicate I/O buffer length\n");
 653                                 usage_server();
 654                                 goto server_exit_error;
 655                         }
 656                         iobuf_len = parse_size(arg);
 657                         if (iobuf_len == (size_t)-1) {
 658                                 usage_server();
 659                                 goto server_exit_error;
 660                         }
 661                 } else if (eqstr(arg, "-cache")) {
 662                         if (++ i >= argc) {
 663                                 fprintf(stderr,
 664                                         "ERROR: no argument for '-cache'\n");
 665                                 usage_server();
 666                                 goto server_exit_error;
 667                         }
 668                         arg = argv[i];
 669                         if (cache_len != (size_t)-1) {
 670                                 fprintf(stderr, "ERROR: duplicate session"
 671                                         " cache length\n");
 672                                 usage_server();
 673                                 goto server_exit_error;
 674                         }
 675                         cache_len = parse_size(arg);
 676                         if (cache_len == (size_t)-1) {
 677                                 usage_server();
 678                                 goto server_exit_error;
 679                         }
 680                 } else if (eqstr(arg, "-cert")) {
 681                         if (++ i >= argc) {
 682                                 fprintf(stderr,
 683                                         "ERROR: no argument for '-cert'\n");
 684                                 usage_server();
 685                                 goto server_exit_error;
 686                         }
 687                         if (chain != NULL) {
 688                                 fprintf(stderr,
 689                                         "ERROR: duplicate certificate chain\n");
 690                                 usage_server();
 691                                 goto server_exit_error;
 692                         }
 693                         arg = argv[i];
 694                         chain = read_certificates(arg, &chain_len);
 695                         if (chain == NULL || chain_len == 0) {
 696                                 goto server_exit_error;
 697                         }
 698                 } else if (eqstr(arg, "-key")) {
 699                         if (++ i >= argc) {
 700                                 fprintf(stderr,
 701                                         "ERROR: no argument for '-key'\n");
 702                                 usage_server();
 703                                 goto server_exit_error;
 704                         }
 705                         if (sk != NULL) {
 706                                 fprintf(stderr,
 707                                         "ERROR: duplicate private key\n");
 708                                 usage_server();
 709                                 goto server_exit_error;
 710                         }
 711                         arg = argv[i];
 712                         sk = read_private_key(arg);
 713                         if (sk == NULL) {
 714                                 goto server_exit_error;
 715                         }
 716                 } else if (eqstr(arg, "-list")) {
 717                         list_names();
 718                         goto server_exit;
 719                 } else if (eqstr(arg, "-vmin")) {
 720                         if (++ i >= argc) {
 721                                 fprintf(stderr,
 722                                         "ERROR: no argument for '-vmin'\n");
 723                                 usage_server();
 724                                 goto server_exit_error;
 725                         }
 726                         arg = argv[i];
 727                         if (vmin != 0) {
 728                                 fprintf(stderr,
 729                                         "ERROR: duplicate minimum version\n");
 730                                 usage_server();
 731                                 goto server_exit_error;
 732                         }
 733                         vmin = parse_version(arg, strlen(arg));
 734                         if (vmin == 0) {
 735                                 fprintf(stderr,
 736                                         "ERROR: unrecognised version '%s'\n",
 737                                         arg);
 738                                 usage_server();
 739                                 goto server_exit_error;
 740                         }
 741                 } else if (eqstr(arg, "-vmax")) {
 742                         if (++ i >= argc) {
 743                                 fprintf(stderr,
 744                                         "ERROR: no argument for '-vmax'\n");
 745                                 usage_server();
 746                                 goto server_exit_error;
 747                         }
 748                         arg = argv[i];
 749                         if (vmax != 0) {
 750                                 fprintf(stderr,
 751                                         "ERROR: duplicate maximum version\n");
 752                                 usage_server();
 753                                 goto server_exit_error;
 754                         }
 755                         vmax = parse_version(arg, strlen(arg));
 756                         if (vmax == 0) {
 757                                 fprintf(stderr,
 758                                         "ERROR: unrecognised version '%s'\n",
 759                                         arg);
 760                                 usage_server();
 761                                 goto server_exit_error;
 762                         }
 763                 } else if (eqstr(arg, "-cs")) {
 764                         if (++ i >= argc) {
 765                                 fprintf(stderr,
 766                                         "ERROR: no argument for '-cs'\n");
 767                                 usage_server();
 768                                 goto server_exit_error;
 769                         }
 770                         arg = argv[i];
 771                         if (suites != NULL) {
 772                                 fprintf(stderr, "ERROR: duplicate list"
 773                                         " of cipher suites\n");
 774                                 usage_server();
 775                                 goto server_exit_error;
 776                         }
 777                         suites = parse_suites(arg, &num_suites);
 778                         if (suites == NULL) {
 779                                 usage_server();
 780                                 goto server_exit_error;
 781                         }
 782                 } else if (eqstr(arg, "-hf")) {
 783                         unsigned x;
 784
 785                         if (++ i >= argc) {
 786                                 fprintf(stderr,
 787                                         "ERROR: no argument for '-hf'\n");
 788                                 usage_server();
 789                                 goto server_exit_error;
 790                         }
 791                         arg = argv[i];
 792                         x = parse_hash_functions(arg);
 793                         if (x == 0) {
 794                                 usage_server();
 795                                 goto server_exit_error;
 796                         }
 797                         hfuns |= x;
 798                 } else if (eqstr(arg, "-serverpref")) {
 799                         flags |= BR_OPT_ENFORCE_SERVER_PREFERENCES;
 800                 } else if (eqstr(arg, "-noreneg")) {
 801                         flags |= BR_OPT_NO_RENEGOTIATION;
 802                 } else {
 803                         fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
 804                         usage_server();
 805                         goto server_exit_error;
 806                 }
 807         }
 808         if (port == NULL) {
 809                 port = "4433";
 810         }
 811         if (vmin == 0) {
 812                 vmin = BR_TLS10;
 813         }
 814         if (vmax == 0) {
 815                 vmax = BR_TLS12;
 816         }
 817         if (vmax < vmin) {
 818                 fprintf(stderr, "ERROR: impossible minimum/maximum protocol"
 819                         " version combination\n");
 820                 usage_server();
 821                 goto server_exit_error;
 822         }
 823         if (suites == NULL) {
 824                 num_suites = 0;
 825
 826                 for (u = 0; cipher_suites[u].name; u ++) {
 827                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 828                                 || vmax >= BR_TLS12)
 829                         {
 830                                 num_suites ++;
 831                         }
 832                 }
 833                 suites = xmalloc(num_suites * sizeof *suites);
 834                 num_suites = 0;
 835                 for (u = 0; cipher_suites[u].name; u ++) {
 836                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 837                                 || vmax >= BR_TLS12)
 838                         {
 839                                 suites[num_suites ++] = cipher_suites[u];
 840                         }
 841                 }
 842         }
 843         if (hfuns == 0) {
 844                 hfuns = (unsigned)-1;
 845         }
 846         if (chain == NULL || chain_len == 0) {
 847                 fprintf(stderr, "ERROR: no certificate chain provided\n");
 848                 goto server_exit_error;
 849         }
 850         if (sk == NULL) {
 851                 fprintf(stderr, "ERROR: no private key provided\n");
 852                 goto server_exit_error;
 853         }
 854         switch (sk->key_type) {
 855                 int curve;
 856                 uint32_t supp;
 857
 858         case BR_KEYTYPE_RSA:
 859                 break;
 860         case BR_KEYTYPE_EC:
 861                 curve = sk->key.ec.curve;
 862                 supp = br_ec_prime_i31.supported_curves;
 863                 if (curve > 31 || !((supp >> curve) & 1)) {
 864                         fprintf(stderr, "ERROR: private key curve (%d)"
 865                                 " is not supported\n", curve);
 866                         goto server_exit_error;
 867                 }
 868                 break;
 869         default:
 870                 fprintf(stderr, "ERROR: unsupported private key type (%d)\n",
 871                         sk->key_type);
 872                 break;
 873         }
 874         cert_signer_algo = get_cert_signer_algo(chain);
 875         if (cert_signer_algo < 0) {
 876                 fprintf(stderr, "ERROR: server certificate cannot be"
 877                         " decoded (err=%d)\n", -cert_signer_algo);
 878                 goto server_exit_error;
 879         } else if (verbose) {
 880                 const char *csas;
 881
 882                 switch (cert_signer_algo) {
 883                 case BR_KEYTYPE_RSA: csas = "RSA"; break;
 884                 case BR_KEYTYPE_EC:  csas = "EC"; break;
 885                 default:
 886                         csas = "unknown";
 887                         break;
 888                 }
 889                 fprintf(stderr, "Issuing CA key type: %d (%s)\n",
 890                         cert_signer_algo, csas);
 891         }
 892         if (iobuf_len == 0) {
 893                 if (bidi) {
 894                         iobuf_len = BR_SSL_BUFSIZE_BIDI;
 895                 } else {
 896                         iobuf_len = BR_SSL_BUFSIZE_MONO;
 897                 }
 898         }
 899         iobuf = xmalloc(iobuf_len);
 900         if (cache_len == (size_t)-1) {
 901                 cache_len = 5000;
 902         }
 903         cache = xmalloc(cache_len);
 904
 905         /*
 906          * Compute implementation requirements and inject implementations.
 907          */
 908         suite_ids = xmalloc(num_suites * sizeof *suite_ids);
 909         br_ssl_server_zero(&cc);
 910         br_ssl_engine_set_versions(&cc.eng, vmin, vmax);
 911         br_ssl_engine_set_all_flags(&cc.eng, flags);
 912         if (vmin <= BR_TLS11) {
 913                 if (!(hfuns & (1 << br_md5_ID))) {
 914                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need MD5\n");
 915                         goto server_exit_error;
 916                 }
 917                 if (!(hfuns & (1 << br_sha1_ID))) {
 918                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need SHA-1\n");
 919                         goto server_exit_error;
 920                 }
 921         }
 922         for (u = 0; u < num_suites; u ++) {
 923                 unsigned req;
 924
 925                 req = suites[u].req;
 926                 suite_ids[u] = suites[u].suite;
 927                 if ((req & REQ_TLS12) != 0 && vmax < BR_TLS12) {
 928                         fprintf(stderr,
 929                                 "ERROR: cipher suite %s requires TLS 1.2\n",
 930                                 suites[u].name);
 931                         goto server_exit_error;
 932                 }
 933                 if ((req & REQ_SHA1) != 0 && !(hfuns & (1 << br_sha1_ID))) {
 934                         fprintf(stderr,
 935                                 "ERROR: cipher suite %s requires SHA-1\n",
 936                                 suites[u].name);
 937                         goto server_exit_error;
 938                 }
 939                 if ((req & REQ_SHA256) != 0 && !(hfuns & (1 << br_sha256_ID))) {
 940                         fprintf(stderr,
 941                                 "ERROR: cipher suite %s requires SHA-256\n",
 942                                 suites[u].name);
 943                         goto server_exit_error;
 944                 }
 945                 if ((req & REQ_SHA384) != 0 && !(hfuns & (1 << br_sha384_ID))) {
 946                         fprintf(stderr,
 947                                 "ERROR: cipher suite %s requires SHA-384\n",
 948                                 suites[u].name);
 949                         goto server_exit_error;
 950                 }
 951                 /* TODO: algorithm implementation selection */
 952                 if ((req & REQ_AESCBC) != 0) {
 953                         br_ssl_engine_set_aes_cbc(&cc.eng,
 954                                 &br_aes_ct_cbcenc_vtable,
 955                                 &br_aes_ct_cbcdec_vtable);
 956                         br_ssl_engine_set_cbc(&cc.eng,
 957                                 &br_sslrec_in_cbc_vtable,
 958                                 &br_sslrec_out_cbc_vtable);
 959                 }
 960                 if ((req & REQ_AESGCM) != 0) {
 961                         br_ssl_engine_set_aes_ctr(&cc.eng,
 962                                 &br_aes_ct_ctr_vtable);
 963                         br_ssl_engine_set_ghash(&cc.eng,
 964                                 &br_ghash_ctmul);
 965                         br_ssl_engine_set_gcm(&cc.eng,
 966                                 &br_sslrec_in_gcm_vtable,
 967                                 &br_sslrec_out_gcm_vtable);
 968                 }
 969                 if ((req & REQ_3DESCBC) != 0) {
 970                         br_ssl_engine_set_des_cbc(&cc.eng,
 971                                 &br_des_ct_cbcenc_vtable,
 972                                 &br_des_ct_cbcdec_vtable);
 973                         br_ssl_engine_set_cbc(&cc.eng,
 974                                 &br_sslrec_in_cbc_vtable,
 975                                 &br_sslrec_out_cbc_vtable);
 976                 }
 977                 if ((req & (REQ_ECDHE_RSA | REQ_ECDHE_ECDSA)) != 0) {
 978                         br_ssl_engine_set_ec(&cc.eng, &br_ec_prime_i31);
 979                 }
 980         }
 981         br_ssl_engine_set_suites(&cc.eng, suite_ids, num_suites);
 982
 983         for (u = 0; hash_functions[u].name; u ++) {
 984                 const br_hash_class *hc;
 985                 int id;
 986
 987                 hc = hash_functions[u].hclass;
 988                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 989                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 990                         br_ssl_engine_set_hash(&cc.eng, id, hc);
 991                 }
 992         }
 993         if (vmin <= BR_TLS11) {
 994                 br_ssl_engine_set_prf10(&cc.eng, &br_tls10_prf);
 995         }
 996         if (vmax >= BR_TLS12) {
 997                 if ((hfuns & ((unsigned)1 << br_sha256_ID)) != 0) {
 998                         br_ssl_engine_set_prf_sha256(&cc.eng,
 999                                 &br_tls12_sha256_prf);
1000                 }
1001                 if ((hfuns & ((unsigned)1 << br_sha384_ID)) != 0) {
1002                         br_ssl_engine_set_prf_sha384(&cc.eng,
1003                                 &br_tls12_sha384_prf);
1004                 }
1005         }
1006
1007         br_ssl_session_cache_lru_init(&lru, cache, cache_len);
1008         br_ssl_server_set_cache(&cc, &lru.vtable);
1009
1010         pc.vtable = &policy_vtable;
1011         pc.verbose = verbose;
1012         pc.chain = chain;
1013         pc.chain_len = chain_len;
1014         pc.cert_signer_algo = cert_signer_algo;
1015         pc.sk = sk;
1016         br_ssl_server_set_policy(&cc, &pc.vtable);
1017
1018         br_ssl_engine_set_buffer(&cc.eng, iobuf, iobuf_len, bidi);
1019
1020         /*
1021          * We need to ignore SIGPIPE.
1022          */
1023         signal(SIGPIPE, SIG_IGN);
1024
1025         /*
1026          * Open the server socket.
1027          */
1028         server_fd = host_bind(bind_name, port, verbose);
1029         if (server_fd < 0) {
1030                 goto server_exit_error;
1031         }
1032
1033         /*
1034          * Process incoming clients, one at a time. Note that we do not
1035          * accept any client until the previous connection has finished:
1036          * this is voluntary, since the tool uses stdin/stdout for
1037          * application data, and thus cannot really run two connections
1038          * simultaneously.
1039          */
1040         for (;;) {
1041                 int x;
1042
1043                 fd = accept_client(server_fd, verbose);
1044                 if (fd < 0) {
1045                         goto server_exit_error;
1046                 }
1047                 br_ssl_server_reset(&cc);
1048                 x = run_ssl_engine(&cc.eng, fd,
1049                         (verbose ? RUN_ENGINE_VERBOSE : 0)
1050                         | (trace ? RUN_ENGINE_TRACE : 0));
1051                 close(fd);
1052                 fd = -1;
1053                 if (x < -1) {
1054                         goto server_exit_error;
1055                 }
1056         }
1057
1058         /*
1059          * Release allocated structures.
1060          */
1061 server_exit:
1062         xfree(suites);
1063         xfree(suite_ids);
1064         if (chain != NULL) {
1065                 for (u = 0; u < chain_len; u ++) {
1066                         xfree(chain[u].data);
1067                 }
1068                 xfree(chain);
1069         }
1070         free_private_key(sk);
1071         xfree(iobuf);
1072         xfree(cache);
1073         if (fd >= 0) {
1074                 close(fd);
1075         }
1076         return retcode;
1077
1078 server_exit_error:
1079         retcode = -1;
1080         goto server_exit;
1081 }