contrib/bearssl/tools/client.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 #ifdef _WIN32
  33 #include <winsock2.h>
  34 #include <ws2tcpip.h>
  35 #else
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <netdb.h>
  39 #include <netinet/in.h>
  40 #include <arpa/inet.h>
  41 #include <unistd.h>
  42 #include <fcntl.h>
  43
  44 #define SOCKET             int
  45 #define INVALID_SOCKET     (-1)
  46 #endif
  47
  48 #include "brssl.h"
  49
  50 static int
  51 host_connect(const char *host, const char *port, int verbose)
  52 {
  53         struct addrinfo hints, *si, *p;
  54         SOCKET fd;
  55         int err;
  56
  57         memset(&hints, 0, sizeof hints);
  58         hints.ai_family = PF_UNSPEC;
  59         hints.ai_socktype = SOCK_STREAM;
  60         err = getaddrinfo(host, port, &hints, &si);
  61         if (err != 0) {
  62                 fprintf(stderr, "ERROR: getaddrinfo(): %s\n",
  63                         gai_strerror(err));
  64                 return INVALID_SOCKET;
  65         }
  66         fd = INVALID_SOCKET;
  67         for (p = si; p != NULL; p = p->ai_next) {
  68                 if (verbose) {
  69                         struct sockaddr *sa;
  70                         void *addr;
  71                         char tmp[INET6_ADDRSTRLEN + 50];
  72
  73                         sa = (struct sockaddr *)p->ai_addr;
  74                         if (sa->sa_family == AF_INET) {
  75                                 addr = &((struct sockaddr_in *)
  76                                         (void *)sa)->sin_addr;
  77                         } else if (sa->sa_family == AF_INET6) {
  78                                 addr = &((struct sockaddr_in6 *)
  79                                         (void *)sa)->sin6_addr;
  80                         } else {
  81                                 addr = NULL;
  82                         }
  83                         if (addr != NULL) {
  84                                 if (!inet_ntop(p->ai_family, addr,
  85                                         tmp, sizeof tmp))
  86                                 {
  87                                         strcpy(tmp, "<invalid>");
  88                                 }
  89                         } else {
  90                                 sprintf(tmp, "<unknown family: %d>",
  91                                         (int)sa->sa_family);
  92                         }
  93                         fprintf(stderr, "connecting to: %s\n", tmp);
  94                 }
  95                 fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
  96                 if (fd == INVALID_SOCKET) {
  97                         if (verbose) {
  98                                 perror("socket()");
  99                         }
 100                         continue;
 101                 }
 102                 if (connect(fd, p->ai_addr, p->ai_addrlen) == INVALID_SOCKET) {
 103                         if (verbose) {
 104                                 perror("connect()");
 105                         }
 106 #ifdef _WIN32
 107                         closesocket(fd);
 108 #else
 109                         close(fd);
 110 #endif
 111                         continue;
 112                 }
 113                 break;
 114         }
 115         if (p == NULL) {
 116                 freeaddrinfo(si);
 117                 fprintf(stderr, "ERROR: failed to connect\n");
 118                 return INVALID_SOCKET;
 119         }
 120         freeaddrinfo(si);
 121         if (verbose) {
 122                 fprintf(stderr, "connected.\n");
 123         }
 124
 125         /*
 126          * We make the socket non-blocking, since we are going to use
 127          * poll() or select() to organise I/O.
 128          */
 129 #ifdef _WIN32
 130         {
 131                 u_long arg;
 132
 133                 arg = 1;
 134                 ioctlsocket(fd, FIONBIO, &arg);
 135         }
 136 #else
 137         fcntl(fd, F_SETFL, O_NONBLOCK);
 138 #endif
 139         return fd;
 140 }
 141
 142 typedef struct {
 143         const br_ssl_client_certificate_class *vtable;
 144         int verbose;
 145         br_x509_certificate *chain;
 146         size_t chain_len;
 147         private_key *sk;
 148         int issuer_key_type;
 149 } ccert_context;
 150
 151 static void
 152 cc_start_name_list(const br_ssl_client_certificate_class **pctx)
 153 {
 154         ccert_context *zc;
 155
 156         zc = (ccert_context *)pctx;
 157         if (zc->verbose) {
 158                 fprintf(stderr, "Server requests a client certificate.\n");
 159                 fprintf(stderr, "--- anchor DN list start ---\n");
 160         }
 161 }
 162
 163 static void
 164 cc_start_name(const br_ssl_client_certificate_class **pctx, size_t len)
 165 {
 166         ccert_context *zc;
 167
 168         zc = (ccert_context *)pctx;
 169         if (zc->verbose) {
 170                 fprintf(stderr, "new anchor name, length = %u\n",
 171                         (unsigned)len);
 172         }
 173 }
 174
 175 static void
 176 cc_append_name(const br_ssl_client_certificate_class **pctx,
 177         const unsigned char *data, size_t len)
 178 {
 179         ccert_context *zc;
 180
 181         zc = (ccert_context *)pctx;
 182         if (zc->verbose) {
 183                 size_t u;
 184
 185                 for (u = 0; u < len; u ++) {
 186                         if (u == 0) {
 187                                 fprintf(stderr, "  ");
 188                         } else if (u > 0 && u % 16 == 0) {
 189                                 fprintf(stderr, "\n  ");
 190                         }
 191                         fprintf(stderr, " %02x", data[u]);
 192                 }
 193                 if (len > 0) {
 194                         fprintf(stderr, "\n");
 195                 }
 196         }
 197 }
 198
 199 static void
 200 cc_end_name(const br_ssl_client_certificate_class **pctx)
 201 {
 202         (void)pctx;
 203 }
 204
 205 static void
 206 cc_end_name_list(const br_ssl_client_certificate_class **pctx)
 207 {
 208         ccert_context *zc;
 209
 210         zc = (ccert_context *)pctx;
 211         if (zc->verbose) {
 212                 fprintf(stderr, "--- anchor DN list end ---\n");
 213         }
 214 }
 215
 216 static void
 217 print_hashes(unsigned hh, unsigned hh2)
 218 {
 219         int i;
 220
 221         for (i = 0; i < 8; i ++) {
 222                 const char *name;
 223
 224                 name = hash_function_name(i);
 225                 if (((hh >> i) & 1) != 0) {
 226                         fprintf(stderr, " %s", name);
 227                 } else if (((hh2 >> i) & 1) != 0) {
 228                         fprintf(stderr, " (%s)", name);
 229                 }
 230         }
 231 }
 232
 233 static int
 234 choose_hash(unsigned hh)
 235 {
 236         static const int f[] = {
 237                 br_sha256_ID, br_sha224_ID, br_sha384_ID, br_sha512_ID,
 238                 br_sha1_ID, br_md5sha1_ID, -1
 239         };
 240
 241         size_t u;
 242
 243         for (u = 0; f[u] >= 0; u ++) {
 244                 if (((hh >> f[u]) & 1) != 0) {
 245                         return f[u];
 246                 }
 247         }
 248         return -1;
 249 }
 250
 251 static void
 252 cc_choose(const br_ssl_client_certificate_class **pctx,
 253         const br_ssl_client_context *cc, uint32_t auth_types,
 254         br_ssl_client_certificate *choices)
 255 {
 256         ccert_context *zc;
 257         int scurve;
 258
 259         zc = (ccert_context *)pctx;
 260         scurve = br_ssl_client_get_server_curve(cc);
 261         if (zc->verbose) {
 262                 unsigned hashes;
 263
 264                 hashes = br_ssl_client_get_server_hashes(cc);
 265                 if ((auth_types & 0x00FF) != 0) {
 266                         fprintf(stderr, "supported: RSA signatures:");
 267                         print_hashes(auth_types, hashes);
 268                         fprintf(stderr, "\n");
 269                 }
 270                 if ((auth_types & 0xFF00) != 0) {
 271                         fprintf(stderr, "supported: ECDSA signatures:");
 272                         print_hashes(auth_types >> 8, hashes >> 8);
 273                         fprintf(stderr, "\n");
 274                 }
 275                 if ((auth_types & 0x010000) != 0) {
 276                         fprintf(stderr, "supported:"
 277                                 " fixed ECDH (cert signed with RSA)\n");
 278                 }
 279                 if ((auth_types & 0x020000) != 0) {
 280                         fprintf(stderr, "supported:"
 281                                 " fixed ECDH (cert signed with ECDSA)\n");
 282                 }
 283                 if (scurve) {
 284                         fprintf(stderr, "server key curve: %s (%d)\n",
 285                                 ec_curve_name(scurve), scurve);
 286                 } else {
 287                         fprintf(stderr, "server key is not EC\n");
 288                 }
 289         }
 290         switch (zc->sk->key_type) {
 291         case BR_KEYTYPE_RSA:
 292                 if ((choices->hash_id = choose_hash(auth_types)) >= 0) {
 293                         if (zc->verbose) {
 294                                 fprintf(stderr, "using RSA, hash = %d (%s)\n",
 295                                         choices->hash_id,
 296                                         hash_function_name(choices->hash_id));
 297                         }
 298                         choices->auth_type = BR_AUTH_RSA;
 299                         choices->chain = zc->chain;
 300                         choices->chain_len = zc->chain_len;
 301                         return;
 302                 }
 303                 break;
 304         case BR_KEYTYPE_EC:
 305                 if (zc->issuer_key_type != 0
 306                         && scurve == zc->sk->key.ec.curve)
 307                 {
 308                         int x;
 309
 310                         x = (zc->issuer_key_type == BR_KEYTYPE_RSA) ? 16 : 17;
 311                         if (((auth_types >> x) & 1) != 0) {
 312                                 if (zc->verbose) {
 313                                         fprintf(stderr, "using static ECDH\n");
 314                                 }
 315                                 choices->auth_type = BR_AUTH_ECDH;
 316                                 choices->hash_id = -1;
 317                                 choices->chain = zc->chain;
 318                                 choices->chain_len = zc->chain_len;
 319                                 return;
 320                         }
 321                 }
 322                 if ((choices->hash_id = choose_hash(auth_types >> 8)) >= 0) {
 323                         if (zc->verbose) {
 324                                 fprintf(stderr, "using ECDSA, hash = %d (%s)\n",
 325                                         choices->hash_id,
 326                                         hash_function_name(choices->hash_id));
 327                         }
 328                         choices->auth_type = BR_AUTH_ECDSA;
 329                         choices->chain = zc->chain;
 330                         choices->chain_len = zc->chain_len;
 331                         return;
 332                 }
 333                 break;
 334         }
 335         if (zc->verbose) {
 336                 fprintf(stderr, "no matching client certificate\n");
 337         }
 338         choices->chain = NULL;
 339         choices->chain_len = 0;
 340 }
 341
 342 static uint32_t
 343 cc_do_keyx(const br_ssl_client_certificate_class **pctx,
 344         unsigned char *data, size_t *len)
 345 {
 346         const br_ec_impl *iec;
 347         ccert_context *zc;
 348         size_t xoff, xlen;
 349         uint32_t r;
 350
 351         zc = (ccert_context *)pctx;
 352         iec = br_ec_get_default();
 353         r = iec->mul(data, *len, zc->sk->key.ec.x,
 354                 zc->sk->key.ec.xlen, zc->sk->key.ec.curve);
 355         xoff = iec->xoff(zc->sk->key.ec.curve, &xlen);
 356         memmove(data, data + xoff, xlen);
 357         *len = xlen;
 358         return r;
 359 }
 360
 361 static size_t
 362 cc_do_sign(const br_ssl_client_certificate_class **pctx,
 363         int hash_id, size_t hv_len, unsigned char *data, size_t len)
 364 {
 365         ccert_context *zc;
 366         unsigned char hv[64];
 367
 368         zc = (ccert_context *)pctx;
 369         memcpy(hv, data, hv_len);
 370         switch (zc->sk->key_type) {
 371                 const br_hash_class *hc;
 372                 const unsigned char *hash_oid;
 373                 uint32_t x;
 374                 size_t sig_len;
 375
 376         case BR_KEYTYPE_RSA:
 377                 hash_oid = get_hash_oid(hash_id);
 378                 if (hash_oid == NULL && hash_id != 0) {
 379                         if (zc->verbose) {
 380                                 fprintf(stderr, "ERROR: cannot RSA-sign with"
 381                                         " unknown hash function: %d\n",
 382                                         hash_id);
 383                         }
 384                         return 0;
 385                 }
 386                 sig_len = (zc->sk->key.rsa.n_bitlen + 7) >> 3;
 387                 if (len < sig_len) {
 388                         if (zc->verbose) {
 389                                 fprintf(stderr, "ERROR: cannot RSA-sign,"
 390                                         " buffer is too small"
 391                                         " (sig=%lu, buf=%lu)\n",
 392                                         (unsigned long)sig_len,
 393                                         (unsigned long)len);
 394                         }
 395                         return 0;
 396                 }
 397                 x = br_rsa_pkcs1_sign_get_default()(
 398                         hash_oid, hv, hv_len, &zc->sk->key.rsa, data);
 399                 if (!x) {
 400                         if (zc->verbose) {
 401                                 fprintf(stderr, "ERROR: RSA-sign failure\n");
 402                         }
 403                         return 0;
 404                 }
 405                 return sig_len;
 406
 407         case BR_KEYTYPE_EC:
 408                 hc = get_hash_impl(hash_id);
 409                 if (hc == NULL) {
 410                         if (zc->verbose) {
 411                                 fprintf(stderr, "ERROR: cannot ECDSA-sign with"
 412                                         " unknown hash function: %d\n",
 413                                         hash_id);
 414                         }
 415                         return 0;
 416                 }
 417                 if (len < 139) {
 418                         if (zc->verbose) {
 419                                 fprintf(stderr, "ERROR: cannot ECDSA-sign"
 420                                         " (output buffer = %lu)\n",
 421                                         (unsigned long)len);
 422                         }
 423                         return 0;
 424                 }
 425                 sig_len = br_ecdsa_sign_asn1_get_default()(
 426                         br_ec_get_default(), hc, hv, &zc->sk->key.ec, data);
 427                 if (sig_len == 0) {
 428                         if (zc->verbose) {
 429                                 fprintf(stderr, "ERROR: ECDSA-sign failure\n");
 430                         }
 431                         return 0;
 432                 }
 433                 return sig_len;
 434
 435         default:
 436                 return 0;
 437         }
 438 }
 439
 440 static const br_ssl_client_certificate_class ccert_vtable = {
 441         sizeof(ccert_context),
 442         cc_start_name_list,
 443         cc_start_name,
 444         cc_append_name,
 445         cc_end_name,
 446         cc_end_name_list,
 447         cc_choose,
 448         cc_do_keyx,
 449         cc_do_sign
 450 };
 451
 452 static void
 453 free_alpn(void *alpn)
 454 {
 455         xfree(*(char **)alpn);
 456 }
 457
 458 static void
 459 usage_client(void)
 460 {
 461         fprintf(stderr,
 462 "usage: brssl client server[:port] [ options ]\n");
 463         fprintf(stderr,
 464 "options:\n");
 465         fprintf(stderr,
 466 "   -q              suppress verbose messages\n");
 467         fprintf(stderr,
 468 "   -trace          activate extra debug messages (dump of all packets)\n");
 469         fprintf(stderr,
 470 "   -sni name       use this specific name for SNI\n");
 471         fprintf(stderr,
 472 "   -nosni          do not send any SNI\n");
 473         fprintf(stderr,
 474 "   -mono           use monodirectional buffering\n");
 475         fprintf(stderr,
 476 "   -buf length     set the I/O buffer length (in bytes)\n");
 477         fprintf(stderr,
 478 "   -CA file        add certificates in 'file' to trust anchors\n");
 479         fprintf(stderr,
 480 "   -cert file      set client certificate chain\n");
 481         fprintf(stderr,
 482 "   -key file       set client private key (for certificate authentication)\n");
 483         fprintf(stderr,
 484 "   -nostaticecdh   prohibit full-static ECDH (client certificate)\n");
 485         fprintf(stderr,
 486 "   -list           list supported names (protocols, algorithms...)\n");
 487         fprintf(stderr,
 488 "   -vmin name      set minimum supported version (default: TLS-1.0)\n");
 489         fprintf(stderr,
 490 "   -vmax name      set maximum supported version (default: TLS-1.2)\n");
 491         fprintf(stderr,
 492 "   -cs names       set list of supported cipher suites (comma-separated)\n");
 493         fprintf(stderr,
 494 "   -hf names       add support for some hash functions (comma-separated)\n");
 495         fprintf(stderr,
 496 "   -minhello len   set minimum ClientHello length (in bytes)\n");
 497         fprintf(stderr,
 498 "   -fallback       send the TLS_FALLBACK_SCSV (i.e. claim a downgrade)\n");
 499         fprintf(stderr,
 500 "   -noreneg        prohibit renegotiations\n");
 501         fprintf(stderr,
 502 "   -alpn name      add protocol name to list of protocols (ALPN extension)\n");
 503         fprintf(stderr,
 504 "   -strictalpn     fail on ALPN mismatch\n");
 505 }
 506
 507 /* see brssl.h */
 508 int
 509 do_client(int argc, char *argv[])
 510 {
 511         int retcode;
 512         int verbose;
 513         int trace;
 514         int i, bidi;
 515         const char *server_name;
 516         char *host;
 517         char *port;
 518         const char *sni;
 519         anchor_list anchors = VEC_INIT;
 520         unsigned vmin, vmax;
 521         VECTOR(char *) alpn_names = VEC_INIT;
 522         cipher_suite *suites;
 523         size_t num_suites;
 524         uint16_t *suite_ids;
 525         unsigned hfuns;
 526         size_t u;
 527         br_ssl_client_context cc;
 528         br_x509_minimal_context xc;
 529         x509_noanchor_context xwc;
 530         const br_hash_class *dnhash;
 531         ccert_context zc;
 532         br_x509_certificate *chain;
 533         size_t chain_len;
 534         private_key *sk;
 535         int nostaticecdh;
 536         unsigned char *iobuf;
 537         size_t iobuf_len;
 538         size_t minhello_len;
 539         int fallback;
 540         uint32_t flags;
 541         SOCKET fd;
 542
 543         retcode = 0;
 544         verbose = 1;
 545         trace = 0;
 546         server_name = NULL;
 547         host = NULL;
 548         port = NULL;
 549         sni = NULL;
 550         bidi = 1;
 551         vmin = 0;
 552         vmax = 0;
 553         suites = NULL;
 554         num_suites = 0;
 555         hfuns = 0;
 556         suite_ids = NULL;
 557         chain = NULL;
 558         chain_len = 0;
 559         sk = NULL;
 560         nostaticecdh = 0;
 561         iobuf = NULL;
 562         iobuf_len = 0;
 563         minhello_len = (size_t)-1;
 564         fallback = 0;
 565         flags = 0;
 566         fd = INVALID_SOCKET;
 567         for (i = 0; i < argc; i ++) {
 568                 const char *arg;
 569
 570                 arg = argv[i];
 571                 if (arg[0] != '-') {
 572                         if (server_name != NULL) {
 573                                 fprintf(stderr,
 574                                         "ERROR: duplicate server name\n");
 575                                 usage_client();
 576                                 goto client_exit_error;
 577                         }
 578                         server_name = arg;
 579                         continue;
 580                 }
 581                 if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
 582                         verbose = 1;
 583                 } else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
 584                         verbose = 0;
 585                 } else if (eqstr(arg, "-trace")) {
 586                         trace = 1;
 587                 } else if (eqstr(arg, "-sni")) {
 588                         if (++ i >= argc) {
 589                                 fprintf(stderr,
 590                                         "ERROR: no argument for '-sni'\n");
 591                                 usage_client();
 592                                 goto client_exit_error;
 593                         }
 594                         if (sni != NULL) {
 595                                 fprintf(stderr, "ERROR: duplicate SNI\n");
 596                                 usage_client();
 597                                 goto client_exit_error;
 598                         }
 599                         sni = argv[i];
 600                 } else if (eqstr(arg, "-nosni")) {
 601                         if (sni != NULL) {
 602                                 fprintf(stderr, "ERROR: duplicate SNI\n");
 603                                 usage_client();
 604                                 goto client_exit_error;
 605                         }
 606                         sni = "";
 607                 } else if (eqstr(arg, "-mono")) {
 608                         bidi = 0;
 609                 } else if (eqstr(arg, "-buf")) {
 610                         if (++ i >= argc) {
 611                                 fprintf(stderr,
 612                                         "ERROR: no argument for '-buf'\n");
 613                                 usage_client();
 614                                 goto client_exit_error;
 615                         }
 616                         arg = argv[i];
 617                         if (iobuf_len != 0) {
 618                                 fprintf(stderr,
 619                                         "ERROR: duplicate I/O buffer length\n");
 620                                 usage_client();
 621                                 goto client_exit_error;
 622                         }
 623                         iobuf_len = parse_size(arg);
 624                         if (iobuf_len == (size_t)-1) {
 625                                 usage_client();
 626                                 goto client_exit_error;
 627                         }
 628                 } else if (eqstr(arg, "-CA")) {
 629                         if (++ i >= argc) {
 630                                 fprintf(stderr,
 631                                         "ERROR: no argument for '-CA'\n");
 632                                 usage_client();
 633                                 goto client_exit_error;
 634                         }
 635                         arg = argv[i];
 636                         if (read_trust_anchors(&anchors, arg) == 0) {
 637                                 usage_client();
 638                                 goto client_exit_error;
 639                         }
 640                 } else if (eqstr(arg, "-cert")) {
 641                         if (++ i >= argc) {
 642                                 fprintf(stderr,
 643                                         "ERROR: no argument for '-cert'\n");
 644                                 usage_client();
 645                                 goto client_exit_error;
 646                         }
 647                         if (chain != NULL) {
 648                                 fprintf(stderr,
 649                                         "ERROR: duplicate certificate chain\n");
 650                                 usage_client();
 651                                 goto client_exit_error;
 652                         }
 653                         arg = argv[i];
 654                         chain = read_certificates(arg, &chain_len);
 655                         if (chain == NULL || chain_len == 0) {
 656                                 goto client_exit_error;
 657                         }
 658                 } else if (eqstr(arg, "-key")) {
 659                         if (++ i >= argc) {
 660                                 fprintf(stderr,
 661                                         "ERROR: no argument for '-key'\n");
 662                                 usage_client();
 663                                 goto client_exit_error;
 664                         }
 665                         if (sk != NULL) {
 666                                 fprintf(stderr,
 667                                         "ERROR: duplicate private key\n");
 668                                 usage_client();
 669                                 goto client_exit_error;
 670                         }
 671                         arg = argv[i];
 672                         sk = read_private_key(arg);
 673                         if (sk == NULL) {
 674                                 goto client_exit_error;
 675                         }
 676                 } else if (eqstr(arg, "-nostaticecdh")) {
 677                         nostaticecdh = 1;
 678                 } else if (eqstr(arg, "-list")) {
 679                         list_names();
 680                         goto client_exit;
 681                 } else if (eqstr(arg, "-vmin")) {
 682                         if (++ i >= argc) {
 683                                 fprintf(stderr,
 684                                         "ERROR: no argument for '-vmin'\n");
 685                                 usage_client();
 686                                 goto client_exit_error;
 687                         }
 688                         arg = argv[i];
 689                         if (vmin != 0) {
 690                                 fprintf(stderr,
 691                                         "ERROR: duplicate minimum version\n");
 692                                 usage_client();
 693                                 goto client_exit_error;
 694                         }
 695                         vmin = parse_version(arg, strlen(arg));
 696                         if (vmin == 0) {
 697                                 fprintf(stderr,
 698                                         "ERROR: unrecognised version '%s'\n",
 699                                         arg);
 700                                 usage_client();
 701                                 goto client_exit_error;
 702                         }
 703                 } else if (eqstr(arg, "-vmax")) {
 704                         if (++ i >= argc) {
 705                                 fprintf(stderr,
 706                                         "ERROR: no argument for '-vmax'\n");
 707                                 usage_client();
 708                                 goto client_exit_error;
 709                         }
 710                         arg = argv[i];
 711                         if (vmax != 0) {
 712                                 fprintf(stderr,
 713                                         "ERROR: duplicate maximum version\n");
 714                                 usage_client();
 715                                 goto client_exit_error;
 716                         }
 717                         vmax = parse_version(arg, strlen(arg));
 718                         if (vmax == 0) {
 719                                 fprintf(stderr,
 720                                         "ERROR: unrecognised version '%s'\n",
 721                                         arg);
 722                                 usage_client();
 723                                 goto client_exit_error;
 724                         }
 725                 } else if (eqstr(arg, "-cs")) {
 726                         if (++ i >= argc) {
 727                                 fprintf(stderr,
 728                                         "ERROR: no argument for '-cs'\n");
 729                                 usage_client();
 730                                 goto client_exit_error;
 731                         }
 732                         arg = argv[i];
 733                         if (suites != NULL) {
 734                                 fprintf(stderr, "ERROR: duplicate list"
 735                                         " of cipher suites\n");
 736                                 usage_client();
 737                                 goto client_exit_error;
 738                         }
 739                         suites = parse_suites(arg, &num_suites);
 740                         if (suites == NULL) {
 741                                 usage_client();
 742                                 goto client_exit_error;
 743                         }
 744                 } else if (eqstr(arg, "-hf")) {
 745                         unsigned x;
 746
 747                         if (++ i >= argc) {
 748                                 fprintf(stderr,
 749                                         "ERROR: no argument for '-hf'\n");
 750                                 usage_client();
 751                                 goto client_exit_error;
 752                         }
 753                         arg = argv[i];
 754                         x = parse_hash_functions(arg);
 755                         if (x == 0) {
 756                                 usage_client();
 757                                 goto client_exit_error;
 758                         }
 759                         hfuns |= x;
 760                 } else if (eqstr(arg, "-minhello")) {
 761                         if (++ i >= argc) {
 762                                 fprintf(stderr,
 763                                         "ERROR: no argument for '-minhello'\n");
 764                                 usage_client();
 765                                 goto client_exit_error;
 766                         }
 767                         arg = argv[i];
 768                         if (minhello_len != (size_t)-1) {
 769                                 fprintf(stderr, "ERROR: duplicate minimum"
 770                                         " ClientHello length\n");
 771                                 usage_client();
 772                                 goto client_exit_error;
 773                         }
 774                         minhello_len = parse_size(arg);
 775                         /*
 776                          * Minimum ClientHello length must fit on 16 bits.
 777                          */
 778                         if (minhello_len == (size_t)-1
 779                                 || (((minhello_len >> 12) >> 4) != 0))
 780                         {
 781                                 usage_client();
 782                                 goto client_exit_error;
 783                         }
 784                 } else if (eqstr(arg, "-fallback")) {
 785                         fallback = 1;
 786                 } else if (eqstr(arg, "-noreneg")) {
 787                         flags |= BR_OPT_NO_RENEGOTIATION;
 788                 } else if (eqstr(arg, "-alpn")) {
 789                         if (++ i >= argc) {
 790                                 fprintf(stderr,
 791                                         "ERROR: no argument for '-alpn'\n");
 792                                 usage_client();
 793                                 goto client_exit_error;
 794                         }
 795                         VEC_ADD(alpn_names, xstrdup(argv[i]));
 796                 } else if (eqstr(arg, "-strictalpn")) {
 797                         flags |= BR_OPT_FAIL_ON_ALPN_MISMATCH;
 798                 } else {
 799                         fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
 800                         usage_client();
 801                         goto client_exit_error;
 802                 }
 803         }
 804         if (server_name == NULL) {
 805                 fprintf(stderr, "ERROR: no server name/address provided\n");
 806                 usage_client();
 807                 goto client_exit_error;
 808         }
 809         for (u = strlen(server_name); u > 0; u --) {
 810                 int c = server_name[u - 1];
 811                 if (c == ':') {
 812                         break;
 813                 }
 814                 if (c < '0' || c > '9') {
 815                         u = 0;
 816                         break;
 817                 }
 818         }
 819         if (u == 0) {
 820                 host = xstrdup(server_name);
 821                 port = xstrdup("443");
 822         } else {
 823                 port = xstrdup(server_name + u);
 824                 host = xmalloc(u);
 825                 memcpy(host, server_name, u - 1);
 826                 host[u - 1] = 0;
 827         }
 828         if (sni == NULL) {
 829                 sni = host;
 830         }
 831
 832         if (chain == NULL && sk != NULL) {
 833                 fprintf(stderr, "ERROR: private key specified, but"
 834                         " no certificate chain\n");
 835                 usage_client();
 836                 goto client_exit_error;
 837         }
 838         if (chain != NULL && sk == NULL) {
 839                 fprintf(stderr, "ERROR: certificate chain specified, but"
 840                         " no private key\n");
 841                 usage_client();
 842                 goto client_exit_error;
 843         }
 844
 845         if (vmin == 0) {
 846                 vmin = BR_TLS10;
 847         }
 848         if (vmax == 0) {
 849                 vmax = BR_TLS12;
 850         }
 851         if (vmax < vmin) {
 852                 fprintf(stderr, "ERROR: impossible minimum/maximum protocol"
 853                         " version combination\n");
 854                 usage_client();
 855                 goto client_exit_error;
 856         }
 857         if (suites == NULL) {
 858                 num_suites = 0;
 859
 860                 for (u = 0; cipher_suites[u].name; u ++) {
 861                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 862                                 || vmax >= BR_TLS12)
 863                         {
 864                                 num_suites ++;
 865                         }
 866                 }
 867                 suites = xmalloc(num_suites * sizeof *suites);
 868                 num_suites = 0;
 869                 for (u = 0; cipher_suites[u].name; u ++) {
 870                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 871                                 || vmax >= BR_TLS12)
 872                         {
 873                                 suites[num_suites ++] = cipher_suites[u];
 874                         }
 875                 }
 876         }
 877         if (hfuns == 0) {
 878                 hfuns = (unsigned)-1;
 879         }
 880         if (iobuf_len == 0) {
 881                 if (bidi) {
 882                         iobuf_len = BR_SSL_BUFSIZE_BIDI;
 883                 } else {
 884                         iobuf_len = BR_SSL_BUFSIZE_MONO;
 885                 }
 886         }
 887         iobuf = xmalloc(iobuf_len);
 888
 889         /*
 890          * Compute implementation requirements and inject implementations.
 891          */
 892         suite_ids = xmalloc((num_suites + 1) * sizeof *suite_ids);
 893         br_ssl_client_zero(&cc);
 894         br_ssl_engine_set_versions(&cc.eng, vmin, vmax);
 895         dnhash = NULL;
 896         for (u = 0; hash_functions[u].name; u ++) {
 897                 const br_hash_class *hc;
 898                 int id;
 899
 900                 hc = hash_functions[u].hclass;
 901                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 902                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 903                         dnhash = hc;
 904                 }
 905         }
 906         if (dnhash == NULL) {
 907                 fprintf(stderr, "ERROR: no supported hash function\n");
 908                 goto client_exit_error;
 909         }
 910         br_x509_minimal_init(&xc, dnhash,
 911                 &VEC_ELT(anchors, 0), VEC_LEN(anchors));
 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 client_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 client_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 client_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 client_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 client_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 client_exit_error;
 950                 }
 951                 /* TODO: algorithm implementation selection */
 952                 if ((req & REQ_AESCBC) != 0) {
 953                         br_ssl_engine_set_default_aes_cbc(&cc.eng);
 954                 }
 955                 if ((req & REQ_AESCCM) != 0) {
 956                         br_ssl_engine_set_default_aes_ccm(&cc.eng);
 957                 }
 958                 if ((req & REQ_AESGCM) != 0) {
 959                         br_ssl_engine_set_default_aes_gcm(&cc.eng);
 960                 }
 961                 if ((req & REQ_CHAPOL) != 0) {
 962                         br_ssl_engine_set_default_chapol(&cc.eng);
 963                 }
 964                 if ((req & REQ_3DESCBC) != 0) {
 965                         br_ssl_engine_set_default_des_cbc(&cc.eng);
 966                 }
 967                 if ((req & REQ_RSAKEYX) != 0) {
 968                         br_ssl_client_set_default_rsapub(&cc);
 969                 }
 970                 if ((req & REQ_ECDHE_RSA) != 0) {
 971                         br_ssl_engine_set_default_ec(&cc.eng);
 972                         br_ssl_engine_set_default_rsavrfy(&cc.eng);
 973                 }
 974                 if ((req & REQ_ECDHE_ECDSA) != 0) {
 975                         br_ssl_engine_set_default_ecdsa(&cc.eng);
 976                 }
 977                 if ((req & REQ_ECDH) != 0) {
 978                         br_ssl_engine_set_default_ec(&cc.eng);
 979                 }
 980         }
 981         if (fallback) {
 982                 suite_ids[num_suites ++] = 0x5600;
 983         }
 984         br_ssl_engine_set_suites(&cc.eng, suite_ids, num_suites);
 985
 986         for (u = 0; hash_functions[u].name; u ++) {
 987                 const br_hash_class *hc;
 988                 int id;
 989
 990                 hc = hash_functions[u].hclass;
 991                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 992                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 993                         br_ssl_engine_set_hash(&cc.eng, id, hc);
 994                         br_x509_minimal_set_hash(&xc, id, hc);
 995                 }
 996         }
 997         if (vmin <= BR_TLS11) {
 998                 br_ssl_engine_set_prf10(&cc.eng, &br_tls10_prf);
 999         }
1000         if (vmax >= BR_TLS12) {
1001                 if ((hfuns & ((unsigned)1 << br_sha256_ID)) != 0) {
1002                         br_ssl_engine_set_prf_sha256(&cc.eng,
1003                                 &br_tls12_sha256_prf);
1004                 }
1005                 if ((hfuns & ((unsigned)1 << br_sha384_ID)) != 0) {
1006                         br_ssl_engine_set_prf_sha384(&cc.eng,
1007                                 &br_tls12_sha384_prf);
1008                 }
1009         }
1010         br_x509_minimal_set_rsa(&xc, br_rsa_pkcs1_vrfy_get_default());
1011         br_x509_minimal_set_ecdsa(&xc,
1012                 br_ec_get_default(), br_ecdsa_vrfy_asn1_get_default());
1013
1014         /*
1015          * If there is no provided trust anchor, then certificate validation
1016          * will always fail. In that situation, we use our custom wrapper
1017          * that tolerates unknown anchors.
1018          */
1019         if (VEC_LEN(anchors) == 0) {
1020                 if (verbose) {
1021                         fprintf(stderr,
1022                                 "WARNING: no configured trust anchor\n");
1023                 }
1024                 x509_noanchor_init(&xwc, &xc.vtable);
1025                 br_ssl_engine_set_x509(&cc.eng, &xwc.vtable);
1026         } else {
1027                 br_ssl_engine_set_x509(&cc.eng, &xc.vtable);
1028         }
1029
1030         if (minhello_len != (size_t)-1) {
1031                 br_ssl_client_set_min_clienthello_len(&cc, minhello_len);
1032         }
1033         br_ssl_engine_set_all_flags(&cc.eng, flags);
1034         if (VEC_LEN(alpn_names) != 0) {
1035                 br_ssl_engine_set_protocol_names(&cc.eng,
1036                         (const char **)&VEC_ELT(alpn_names, 0),
1037                         VEC_LEN(alpn_names));
1038         }
1039
1040         if (chain != NULL) {
1041                 zc.vtable = &ccert_vtable;
1042                 zc.verbose = verbose;
1043                 zc.chain = chain;
1044                 zc.chain_len = chain_len;
1045                 zc.sk = sk;
1046                 if (nostaticecdh || sk->key_type != BR_KEYTYPE_EC) {
1047                         zc.issuer_key_type = 0;
1048                 } else {
1049                         zc.issuer_key_type = get_cert_signer_algo(&chain[0]);
1050                         if (zc.issuer_key_type == 0) {
1051                                 goto client_exit_error;
1052                         }
1053                 }
1054                 br_ssl_client_set_client_certificate(&cc, &zc.vtable);
1055         }
1056
1057         br_ssl_engine_set_buffer(&cc.eng, iobuf, iobuf_len, bidi);
1058         br_ssl_client_reset(&cc, sni, 0);
1059
1060         /*
1061          * On Unix systems, we need to avoid SIGPIPE.
1062          */
1063 #ifndef _WIN32
1064         signal(SIGPIPE, SIG_IGN);
1065 #endif
1066
1067         /*
1068          * Connect to the peer.
1069          */
1070         fd = host_connect(host, port, verbose);
1071         if (fd == INVALID_SOCKET) {
1072                 goto client_exit_error;
1073         }
1074
1075         /*
1076          * Run the engine until completion.
1077          */
1078         if (run_ssl_engine(&cc.eng, fd,
1079                 (verbose ? RUN_ENGINE_VERBOSE : 0)
1080                 | (trace ? RUN_ENGINE_TRACE : 0)) != 0)
1081         {
1082                 goto client_exit_error;
1083         } else {
1084                 goto client_exit;
1085         }
1086
1087         /*
1088          * Release allocated structures.
1089          */
1090 client_exit:
1091         xfree(host);
1092         xfree(port);
1093         xfree(suites);
1094         xfree(suite_ids);
1095         VEC_CLEAREXT(anchors, &free_ta_contents);
1096         VEC_CLEAREXT(alpn_names, &free_alpn);
1097         free_certificates(chain, chain_len);
1098         free_private_key(sk);
1099         xfree(iobuf);
1100         if (fd != INVALID_SOCKET) {
1101 #ifdef _WIN32
1102                 closesocket(fd);
1103 #else
1104                 close(fd);
1105 #endif
1106         }
1107         return retcode;
1108
1109 client_exit_error:
1110         retcode = -1;
1111         goto client_exit;
1112 }