_ Git - BearSSL/blob - 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 *)sa)->sin_addr;
  76                         } else if (sa->sa_family == AF_INET6) {
  77                                 addr = &((struct sockaddr_in6 *)sa)->sin6_addr;
  78                         } else {
  79                                 addr = NULL;
  80                         }
  81                         if (addr != NULL) {
  82                                 if (!inet_ntop(p->ai_family, addr,
  83                                         tmp, sizeof tmp))
  84                                 {
  85                                         strcpy(tmp, "<invalid>");
  86                                 }
  87                         } else {
  88                                 sprintf(tmp, "<unknown family: %d>",
  89                                         (int)sa->sa_family);
  90                         }
  91                         fprintf(stderr, "connecting to: %s\n", tmp);
  92                 }
  93                 fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
  94                 if (fd == INVALID_SOCKET) {
  95                         if (verbose) {
  96                                 perror("socket()");
  97                         }
  98                         continue;
  99                 }
 100                 if (connect(fd, p->ai_addr, p->ai_addrlen) == INVALID_SOCKET) {
 101                         if (verbose) {
 102                                 perror("connect()");
 103                         }
 104 #ifdef _WIN32
 105                         closesocket(fd);
 106 #else
 107                         close(fd);
 108 #endif
 109                         continue;
 110                 }
 111                 break;
 112         }
 113         if (p == NULL) {
 114                 freeaddrinfo(si);
 115                 fprintf(stderr, "ERROR: failed to connect\n");
 116                 return INVALID_SOCKET;
 117         }
 118         freeaddrinfo(si);
 119         if (verbose) {
 120                 fprintf(stderr, "connected.\n");
 121         }
 122
 123         /*
 124          * We make the socket non-blocking, since we are going to use
 125          * poll() or select() to organise I/O.
 126          */
 127 #ifdef _WIN32
 128         {
 129                 u_long arg;
 130
 131                 arg = 1;
 132                 ioctlsocket(fd, FIONBIO, &arg);
 133         }
 134 #else
 135         fcntl(fd, F_SETFL, O_NONBLOCK);
 136 #endif
 137         return fd;
 138 }
 139
 140 typedef struct {
 141         const br_ssl_client_certificate_class *vtable;
 142         int verbose;
 143         br_x509_certificate *chain;
 144         size_t chain_len;
 145         private_key *sk;
 146         int issuer_key_type;
 147 } ccert_context;
 148
 149 static void
 150 cc_start_name_list(const br_ssl_client_certificate_class **pctx)
 151 {
 152         ccert_context *zc;
 153
 154         zc = (ccert_context *)pctx;
 155         if (zc->verbose) {
 156                 fprintf(stderr, "Server requests a client certificate.\n");
 157                 fprintf(stderr, "--- anchor DN list start ---\n");
 158         }
 159 }
 160
 161 static void
 162 cc_start_name(const br_ssl_client_certificate_class **pctx, size_t len)
 163 {
 164         ccert_context *zc;
 165
 166         zc = (ccert_context *)pctx;
 167         if (zc->verbose) {
 168                 fprintf(stderr, "new anchor name, length = %u\n",
 169                         (unsigned)len);
 170         }
 171 }
 172
 173 static void
 174 cc_append_name(const br_ssl_client_certificate_class **pctx,
 175         const unsigned char *data, size_t len)
 176 {
 177         ccert_context *zc;
 178
 179         zc = (ccert_context *)pctx;
 180         if (zc->verbose) {
 181                 size_t u;
 182
 183                 for (u = 0; u < len; u ++) {
 184                         if (u == 0) {
 185                                 fprintf(stderr, "  ");
 186                         } else if (u > 0 && u % 16 == 0) {
 187                                 fprintf(stderr, "\n  ");
 188                         }
 189                         fprintf(stderr, " %02x", data[u]);
 190                 }
 191                 if (len > 0) {
 192                         fprintf(stderr, "\n");
 193                 }
 194         }
 195 }
 196
 197 static void
 198 cc_end_name(const br_ssl_client_certificate_class **pctx)
 199 {
 200         (void)pctx;
 201 }
 202
 203 static void
 204 cc_end_name_list(const br_ssl_client_certificate_class **pctx)
 205 {
 206         ccert_context *zc;
 207
 208         zc = (ccert_context *)pctx;
 209         if (zc->verbose) {
 210                 fprintf(stderr, "--- anchor DN list end ---\n");
 211         }
 212 }
 213
 214 static void
 215 print_hashes(unsigned hh, unsigned hh2)
 216 {
 217         int i;
 218
 219         for (i = 0; i < 8; i ++) {
 220                 const char *name;
 221
 222                 name = hash_function_name(i);
 223                 if (((hh >> i) & 1) != 0) {
 224                         fprintf(stderr, " %s", name);
 225                 } else if (((hh2 >> i) & 1) != 0) {
 226                         fprintf(stderr, " (%s)", name);
 227                 }
 228         }
 229 }
 230
 231 static int
 232 choose_hash(unsigned hh)
 233 {
 234         static const int f[] = {
 235                 br_sha256_ID, br_sha224_ID, br_sha384_ID, br_sha512_ID,
 236                 br_sha1_ID, br_md5sha1_ID, -1
 237         };
 238
 239         size_t u;
 240
 241         for (u = 0; f[u] >= 0; u ++) {
 242                 if (((hh >> f[u]) & 1) != 0) {
 243                         return f[u];
 244                 }
 245         }
 246         return -1;
 247 }
 248
 249 static void
 250 cc_choose(const br_ssl_client_certificate_class **pctx,
 251         const br_ssl_client_context *cc, uint32_t auth_types,
 252         br_ssl_client_certificate *choices)
 253 {
 254         ccert_context *zc;
 255         int scurve;
 256
 257         zc = (ccert_context *)pctx;
 258         scurve = br_ssl_client_get_server_curve(cc);
 259         if (zc->verbose) {
 260                 unsigned hashes;
 261
 262                 hashes = br_ssl_client_get_server_hashes(cc);
 263                 if ((auth_types & 0x00FF) != 0) {
 264                         fprintf(stderr, "supported: RSA signatures:");
 265                         print_hashes(auth_types, hashes);
 266                         fprintf(stderr, "\n");
 267                 }
 268                 if ((auth_types & 0xFF00) != 0) {
 269                         fprintf(stderr, "supported: ECDSA signatures:");
 270                         print_hashes(auth_types >> 8, hashes >> 8);
 271                         fprintf(stderr, "\n");
 272                 }
 273                 if ((auth_types & 0x010000) != 0) {
 274                         fprintf(stderr, "supported:"
 275                                 " fixed ECDH (cert signed with RSA)\n");
 276                 }
 277                 if ((auth_types & 0x020000) != 0) {
 278                         fprintf(stderr, "supported:"
 279                                 " fixed ECDH (cert signed with ECDSA)\n");
 280                 }
 281                 if (scurve) {
 282                         fprintf(stderr, "server key curve: %s (%d)\n",
 283                                 ec_curve_name(scurve), scurve);
 284                 } else {
 285                         fprintf(stderr, "server key is not EC\n");
 286                 }
 287         }
 288         switch (zc->sk->key_type) {
 289         case BR_KEYTYPE_RSA:
 290                 if ((choices->hash_id = choose_hash(auth_types)) >= 0) {
 291                         if (zc->verbose) {
 292                                 fprintf(stderr, "using RSA, hash = %d (%s)\n",
 293                                         choices->hash_id,
 294                                         hash_function_name(choices->hash_id));
 295                         }
 296                         choices->auth_type = BR_AUTH_RSA;
 297                         choices->chain = zc->chain;
 298                         choices->chain_len = zc->chain_len;
 299                         return;
 300                 }
 301                 break;
 302         case BR_KEYTYPE_EC:
 303                 if (zc->issuer_key_type != 0
 304                         && scurve == zc->sk->key.ec.curve)
 305                 {
 306                         int x;
 307
 308                         x = (zc->issuer_key_type == BR_KEYTYPE_RSA) ? 16 : 17;
 309                         if (((auth_types >> x) & 1) != 0) {
 310                                 if (zc->verbose) {
 311                                         fprintf(stderr, "using static ECDH\n");
 312                                 }
 313                                 choices->auth_type = BR_AUTH_ECDH;
 314                                 choices->hash_id = -1;
 315                                 choices->chain = zc->chain;
 316                                 choices->chain_len = zc->chain_len;
 317                                 return;
 318                         }
 319                 }
 320                 if ((choices->hash_id = choose_hash(auth_types >> 8)) >= 0) {
 321                         if (zc->verbose) {
 322                                 fprintf(stderr, "using ECDSA, hash = %d (%s)\n",
 323                                         choices->hash_id,
 324                                         hash_function_name(choices->hash_id));
 325                         }
 326                         choices->auth_type = BR_AUTH_ECDSA;
 327                         choices->chain = zc->chain;
 328                         choices->chain_len = zc->chain_len;
 329                         return;
 330                 }
 331                 break;
 332         }
 333         if (zc->verbose) {
 334                 fprintf(stderr, "no matching client certificate\n");
 335         }
 336         choices->chain = NULL;
 337         choices->chain_len = 0;
 338 }
 339
 340 static uint32_t
 341 cc_do_keyx(const br_ssl_client_certificate_class **pctx,
 342         unsigned char *data, size_t *len)
 343 {
 344         const br_ec_impl *iec;
 345         ccert_context *zc;
 346         size_t xoff, xlen;
 347         uint32_t r;
 348
 349         zc = (ccert_context *)pctx;
 350         iec = br_ec_get_default();
 351         r = iec->mul(data, *len, zc->sk->key.ec.x,
 352                 zc->sk->key.ec.xlen, zc->sk->key.ec.curve);
 353         xoff = iec->xoff(zc->sk->key.ec.curve, &xlen);
 354         memmove(data, data + xoff, xlen);
 355         *len = xlen;
 356         return r;
 357 }
 358
 359 static size_t
 360 cc_do_sign(const br_ssl_client_certificate_class **pctx,
 361         int hash_id, size_t hv_len, unsigned char *data, size_t len)
 362 {
 363         ccert_context *zc;
 364         unsigned char hv[64];
 365
 366         zc = (ccert_context *)pctx;
 367         memcpy(hv, data, hv_len);
 368         switch (zc->sk->key_type) {
 369                 const br_hash_class *hc;
 370                 const unsigned char *hash_oid;
 371                 uint32_t x;
 372                 size_t sig_len;
 373
 374         case BR_KEYTYPE_RSA:
 375                 hash_oid = get_hash_oid(hash_id);
 376                 if (hash_oid == NULL && hash_id != 0) {
 377                         if (zc->verbose) {
 378                                 fprintf(stderr, "ERROR: cannot RSA-sign with"
 379                                         " unknown hash function: %d\n",
 380                                         hash_id);
 381                         }
 382                         return 0;
 383                 }
 384                 sig_len = (zc->sk->key.rsa.n_bitlen + 7) >> 3;
 385                 if (len < sig_len) {
 386                         if (zc->verbose) {
 387                                 fprintf(stderr, "ERROR: cannot RSA-sign,"
 388                                         " buffer is too small"
 389                                         " (sig=%lu, buf=%lu)\n",
 390                                         (unsigned long)sig_len,
 391                                         (unsigned long)len);
 392                         }
 393                         return 0;
 394                 }
 395                 x = br_rsa_pkcs1_sign_get_default()(
 396                         hash_oid, hv, hv_len, &zc->sk->key.rsa, data);
 397                 if (!x) {
 398                         if (zc->verbose) {
 399                                 fprintf(stderr, "ERROR: RSA-sign failure\n");
 400                         }
 401                         return 0;
 402                 }
 403                 return sig_len;
 404
 405         case BR_KEYTYPE_EC:
 406                 hc = get_hash_impl(hash_id);
 407                 if (hc == NULL) {
 408                         if (zc->verbose) {
 409                                 fprintf(stderr, "ERROR: cannot ECDSA-sign with"
 410                                         " unknown hash function: %d\n",
 411                                         hash_id);
 412                         }
 413                         return 0;
 414                 }
 415                 if (len < 139) {
 416                         if (zc->verbose) {
 417                                 fprintf(stderr, "ERROR: cannot ECDSA-sign"
 418                                         " (output buffer = %lu)\n",
 419                                         (unsigned long)len);
 420                         }
 421                         return 0;
 422                 }
 423                 sig_len = br_ecdsa_sign_asn1_get_default()(
 424                         br_ec_get_default(), hc, hv, &zc->sk->key.ec, data);
 425                 if (sig_len == 0) {
 426                         if (zc->verbose) {
 427                                 fprintf(stderr, "ERROR: ECDSA-sign failure\n");
 428                         }
 429                         return 0;
 430                 }
 431                 return sig_len;
 432
 433         default:
 434                 return 0;
 435         }
 436 }
 437
 438 static const br_ssl_client_certificate_class ccert_vtable = {
 439         sizeof(ccert_context),
 440         cc_start_name_list,
 441         cc_start_name,
 442         cc_append_name,
 443         cc_end_name,
 444         cc_end_name_list,
 445         cc_choose,
 446         cc_do_keyx,
 447         cc_do_sign
 448 };
 449
 450 static void
 451 free_alpn(void *alpn)
 452 {
 453         xfree(*(char **)alpn);
 454 }
 455
 456 static void
 457 usage_client(void)
 458 {
 459         fprintf(stderr,
 460 "usage: brssl client server[:port] [ options ]\n");
 461         fprintf(stderr,
 462 "options:\n");
 463         fprintf(stderr,
 464 "   -q              suppress verbose messages\n");
 465         fprintf(stderr,
 466 "   -trace          activate extra debug messages (dump of all packets)\n");
 467         fprintf(stderr,
 468 "   -sni name       use this specific name for SNI\n");
 469         fprintf(stderr,
 470 "   -nosni          do not send any SNI\n");
 471         fprintf(stderr,
 472 "   -mono           use monodirectional buffering\n");
 473         fprintf(stderr,
 474 "   -buf length     set the I/O buffer length (in bytes)\n");
 475         fprintf(stderr,
 476 "   -CA file        add certificates in 'file' to trust anchors\n");
 477         fprintf(stderr,
 478 "   -cert file      set client certificate chain\n");
 479         fprintf(stderr,
 480 "   -key file       set client private key (for certificate authentication)\n");
 481         fprintf(stderr,
 482 "   -nostaticecdh   prohibit full-static ECDH (client certificate)\n");
 483         fprintf(stderr,
 484 "   -list           list supported names (protocols, algorithms...)\n");
 485         fprintf(stderr,
 486 "   -vmin name      set minimum supported version (default: TLS-1.0)\n");
 487         fprintf(stderr,
 488 "   -vmax name      set maximum supported version (default: TLS-1.2)\n");
 489         fprintf(stderr,
 490 "   -cs names       set list of supported cipher suites (comma-separated)\n");
 491         fprintf(stderr,
 492 "   -hf names       add support for some hash functions (comma-separated)\n");
 493         fprintf(stderr,
 494 "   -minhello len   set minimum ClientHello length (in bytes)\n");
 495         fprintf(stderr,
 496 "   -fallback       send the TLS_FALLBACK_SCSV (i.e. claim a downgrade)\n");
 497         fprintf(stderr,
 498 "   -noreneg        prohibit renegotiations\n");
 499         fprintf(stderr,
 500 "   -alpn name      add protocol name to list of protocols (ALPN extension)\n");
 501         fprintf(stderr,
 502 "   -strictalpn     fail on ALPN mismatch\n");
 503 }
 504
 505 /* see brssl.h */
 506 int
 507 do_client(int argc, char *argv[])
 508 {
 509         int retcode;
 510         int verbose;
 511         int trace;
 512         int i, bidi;
 513         const char *server_name;
 514         char *host;
 515         char *port;
 516         const char *sni;
 517         anchor_list anchors = VEC_INIT;
 518         unsigned vmin, vmax;
 519         VECTOR(char *) alpn_names = VEC_INIT;
 520         cipher_suite *suites;
 521         size_t num_suites;
 522         uint16_t *suite_ids;
 523         unsigned hfuns;
 524         size_t u;
 525         br_ssl_client_context cc;
 526         br_x509_minimal_context xc;
 527         x509_noanchor_context xwc;
 528         const br_hash_class *dnhash;
 529         ccert_context zc;
 530         br_x509_certificate *chain;
 531         size_t chain_len;
 532         private_key *sk;
 533         int nostaticecdh;
 534         unsigned char *iobuf;
 535         size_t iobuf_len;
 536         size_t minhello_len;
 537         int fallback;
 538         uint32_t flags;
 539         SOCKET fd;
 540
 541         retcode = 0;
 542         verbose = 1;
 543         trace = 0;
 544         server_name = NULL;
 545         host = NULL;
 546         port = NULL;
 547         sni = NULL;
 548         bidi = 1;
 549         vmin = 0;
 550         vmax = 0;
 551         suites = NULL;
 552         num_suites = 0;
 553         hfuns = 0;
 554         suite_ids = NULL;
 555         chain = NULL;
 556         chain_len = 0;
 557         sk = NULL;
 558         nostaticecdh = 0;
 559         iobuf = NULL;
 560         iobuf_len = 0;
 561         minhello_len = (size_t)-1;
 562         fallback = 0;
 563         flags = 0;
 564         fd = INVALID_SOCKET;
 565         for (i = 0; i < argc; i ++) {
 566                 const char *arg;
 567
 568                 arg = argv[i];
 569                 if (arg[0] != '-') {
 570                         if (server_name != NULL) {
 571                                 fprintf(stderr,
 572                                         "ERROR: duplicate server name\n");
 573                                 usage_client();
 574                                 goto client_exit_error;
 575                         }
 576                         server_name = arg;
 577                         continue;
 578                 }
 579                 if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
 580                         verbose = 1;
 581                 } else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
 582                         verbose = 0;
 583                 } else if (eqstr(arg, "-trace")) {
 584                         trace = 1;
 585                 } else if (eqstr(arg, "-sni")) {
 586                         if (++ i >= argc) {
 587                                 fprintf(stderr,
 588                                         "ERROR: no argument for '-sni'\n");
 589                                 usage_client();
 590                                 goto client_exit_error;
 591                         }
 592                         if (sni != NULL) {
 593                                 fprintf(stderr, "ERROR: duplicate SNI\n");
 594                                 usage_client();
 595                                 goto client_exit_error;
 596                         }
 597                         sni = argv[i];
 598                 } else if (eqstr(arg, "-nosni")) {
 599                         if (sni != NULL) {
 600                                 fprintf(stderr, "ERROR: duplicate SNI\n");
 601                                 usage_client();
 602                                 goto client_exit_error;
 603                         }
 604                         sni = "";
 605                 } else if (eqstr(arg, "-mono")) {
 606                         bidi = 0;
 607                 } else if (eqstr(arg, "-buf")) {
 608                         if (++ i >= argc) {
 609                                 fprintf(stderr,
 610                                         "ERROR: no argument for '-buf'\n");
 611                                 usage_client();
 612                                 goto client_exit_error;
 613                         }
 614                         arg = argv[i];
 615                         if (iobuf_len != 0) {
 616                                 fprintf(stderr,
 617                                         "ERROR: duplicate I/O buffer length\n");
 618                                 usage_client();
 619                                 goto client_exit_error;
 620                         }
 621                         iobuf_len = parse_size(arg);
 622                         if (iobuf_len == (size_t)-1) {
 623                                 usage_client();
 624                                 goto client_exit_error;
 625                         }
 626                 } else if (eqstr(arg, "-CA")) {
 627                         if (++ i >= argc) {
 628                                 fprintf(stderr,
 629                                         "ERROR: no argument for '-CA'\n");
 630                                 usage_client();
 631                                 goto client_exit_error;
 632                         }
 633                         arg = argv[i];
 634                         if (read_trust_anchors(&anchors, arg) == 0) {
 635                                 usage_client();
 636                                 goto client_exit_error;
 637                         }
 638                 } else if (eqstr(arg, "-cert")) {
 639                         if (++ i >= argc) {
 640                                 fprintf(stderr,
 641                                         "ERROR: no argument for '-cert'\n");
 642                                 usage_client();
 643                                 goto client_exit_error;
 644                         }
 645                         if (chain != NULL) {
 646                                 fprintf(stderr,
 647                                         "ERROR: duplicate certificate chain\n");
 648                                 usage_client();
 649                                 goto client_exit_error;
 650                         }
 651                         arg = argv[i];
 652                         chain = read_certificates(arg, &chain_len);
 653                         if (chain == NULL || chain_len == 0) {
 654                                 goto client_exit_error;
 655                         }
 656                 } else if (eqstr(arg, "-key")) {
 657                         if (++ i >= argc) {
 658                                 fprintf(stderr,
 659                                         "ERROR: no argument for '-key'\n");
 660                                 usage_client();
 661                                 goto client_exit_error;
 662                         }
 663                         if (sk != NULL) {
 664                                 fprintf(stderr,
 665                                         "ERROR: duplicate private key\n");
 666                                 usage_client();
 667                                 goto client_exit_error;
 668                         }
 669                         arg = argv[i];
 670                         sk = read_private_key(arg);
 671                         if (sk == NULL) {
 672                                 goto client_exit_error;
 673                         }
 674                 } else if (eqstr(arg, "-nostaticecdh")) {
 675                         nostaticecdh = 1;
 676                 } else if (eqstr(arg, "-list")) {
 677                         list_names();
 678                         goto client_exit;
 679                 } else if (eqstr(arg, "-vmin")) {
 680                         if (++ i >= argc) {
 681                                 fprintf(stderr,
 682                                         "ERROR: no argument for '-vmin'\n");
 683                                 usage_client();
 684                                 goto client_exit_error;
 685                         }
 686                         arg = argv[i];
 687                         if (vmin != 0) {
 688                                 fprintf(stderr,
 689                                         "ERROR: duplicate minimum version\n");
 690                                 usage_client();
 691                                 goto client_exit_error;
 692                         }
 693                         vmin = parse_version(arg, strlen(arg));
 694                         if (vmin == 0) {
 695                                 fprintf(stderr,
 696                                         "ERROR: unrecognised version '%s'\n",
 697                                         arg);
 698                                 usage_client();
 699                                 goto client_exit_error;
 700                         }
 701                 } else if (eqstr(arg, "-vmax")) {
 702                         if (++ i >= argc) {
 703                                 fprintf(stderr,
 704                                         "ERROR: no argument for '-vmax'\n");
 705                                 usage_client();
 706                                 goto client_exit_error;
 707                         }
 708                         arg = argv[i];
 709                         if (vmax != 0) {
 710                                 fprintf(stderr,
 711                                         "ERROR: duplicate maximum version\n");
 712                                 usage_client();
 713                                 goto client_exit_error;
 714                         }
 715                         vmax = parse_version(arg, strlen(arg));
 716                         if (vmax == 0) {
 717                                 fprintf(stderr,
 718                                         "ERROR: unrecognised version '%s'\n",
 719                                         arg);
 720                                 usage_client();
 721                                 goto client_exit_error;
 722                         }
 723                 } else if (eqstr(arg, "-cs")) {
 724                         if (++ i >= argc) {
 725                                 fprintf(stderr,
 726                                         "ERROR: no argument for '-cs'\n");
 727                                 usage_client();
 728                                 goto client_exit_error;
 729                         }
 730                         arg = argv[i];
 731                         if (suites != NULL) {
 732                                 fprintf(stderr, "ERROR: duplicate list"
 733                                         " of cipher suites\n");
 734                                 usage_client();
 735                                 goto client_exit_error;
 736                         }
 737                         suites = parse_suites(arg, &num_suites);
 738                         if (suites == NULL) {
 739                                 usage_client();
 740                                 goto client_exit_error;
 741                         }
 742                 } else if (eqstr(arg, "-hf")) {
 743                         unsigned x;
 744
 745                         if (++ i >= argc) {
 746                                 fprintf(stderr,
 747                                         "ERROR: no argument for '-hf'\n");
 748                                 usage_client();
 749                                 goto client_exit_error;
 750                         }
 751                         arg = argv[i];
 752                         x = parse_hash_functions(arg);
 753                         if (x == 0) {
 754                                 usage_client();
 755                                 goto client_exit_error;
 756                         }
 757                         hfuns |= x;
 758                 } else if (eqstr(arg, "-minhello")) {
 759                         if (++ i >= argc) {
 760                                 fprintf(stderr,
 761                                         "ERROR: no argument for '-minhello'\n");
 762                                 usage_client();
 763                                 goto client_exit_error;
 764                         }
 765                         arg = argv[i];
 766                         if (minhello_len != (size_t)-1) {
 767                                 fprintf(stderr, "ERROR: duplicate minimum"
 768                                         " ClientHello length\n");
 769                                 usage_client();
 770                                 goto client_exit_error;
 771                         }
 772                         minhello_len = parse_size(arg);
 773                         /*
 774                          * Minimum ClientHello length must fit on 16 bits.
 775                          */
 776                         if (minhello_len == (size_t)-1
 777                                 || (((minhello_len >> 12) >> 4) != 0))
 778                         {
 779                                 usage_client();
 780                                 goto client_exit_error;
 781                         }
 782                 } else if (eqstr(arg, "-fallback")) {
 783                         fallback = 1;
 784                 } else if (eqstr(arg, "-noreneg")) {
 785                         flags |= BR_OPT_NO_RENEGOTIATION;
 786                 } else if (eqstr(arg, "-alpn")) {
 787                         if (++ i >= argc) {
 788                                 fprintf(stderr,
 789                                         "ERROR: no argument for '-alpn'\n");
 790                                 usage_client();
 791                                 goto client_exit_error;
 792                         }
 793                         VEC_ADD(alpn_names, xstrdup(argv[i]));
 794                 } else if (eqstr(arg, "-strictalpn")) {
 795                         flags |= BR_OPT_FAIL_ON_ALPN_MISMATCH;
 796                 } else {
 797                         fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
 798                         usage_client();
 799                         goto client_exit_error;
 800                 }
 801         }
 802         if (server_name == NULL) {
 803                 fprintf(stderr, "ERROR: no server name/address provided\n");
 804                 usage_client();
 805                 goto client_exit_error;
 806         }
 807         for (u = strlen(server_name); u > 0; u --) {
 808                 int c = server_name[u - 1];
 809                 if (c == ':') {
 810                         break;
 811                 }
 812                 if (c < '0' || c > '9') {
 813                         u = 0;
 814                         break;
 815                 }
 816         }
 817         if (u == 0) {
 818                 host = xstrdup(server_name);
 819                 port = xstrdup("443");
 820         } else {
 821                 port = xstrdup(server_name + u);
 822                 host = xmalloc(u);
 823                 memcpy(host, server_name, u - 1);
 824                 host[u - 1] = 0;
 825         }
 826         if (sni == NULL) {
 827                 sni = host;
 828         }
 829
 830         if (chain == NULL && sk != NULL) {
 831                 fprintf(stderr, "ERROR: private key specified, but"
 832                         " no certificate chain\n");
 833                 usage_client();
 834                 goto client_exit_error;
 835         }
 836         if (chain != NULL && sk == NULL) {
 837                 fprintf(stderr, "ERROR: certificate chain specified, but"
 838                         " no private key\n");
 839                 usage_client();
 840                 goto client_exit_error;
 841         }
 842
 843         if (vmin == 0) {
 844                 vmin = BR_TLS10;
 845         }
 846         if (vmax == 0) {
 847                 vmax = BR_TLS12;
 848         }
 849         if (vmax < vmin) {
 850                 fprintf(stderr, "ERROR: impossible minimum/maximum protocol"
 851                         " version combination\n");
 852                 usage_client();
 853                 goto client_exit_error;
 854         }
 855         if (suites == NULL) {
 856                 num_suites = 0;
 857
 858                 for (u = 0; cipher_suites[u].name; u ++) {
 859                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 860                                 || vmax >= BR_TLS12)
 861                         {
 862                                 num_suites ++;
 863                         }
 864                 }
 865                 suites = xmalloc(num_suites * sizeof *suites);
 866                 num_suites = 0;
 867                 for (u = 0; cipher_suites[u].name; u ++) {
 868                         if ((cipher_suites[u].req & REQ_TLS12) == 0
 869                                 || vmax >= BR_TLS12)
 870                         {
 871                                 suites[num_suites ++] = cipher_suites[u];
 872                         }
 873                 }
 874         }
 875         if (hfuns == 0) {
 876                 hfuns = (unsigned)-1;
 877         }
 878         if (iobuf_len == 0) {
 879                 if (bidi) {
 880                         iobuf_len = BR_SSL_BUFSIZE_BIDI;
 881                 } else {
 882                         iobuf_len = BR_SSL_BUFSIZE_MONO;
 883                 }
 884         }
 885         iobuf = xmalloc(iobuf_len);
 886
 887         /*
 888          * Compute implementation requirements and inject implementations.
 889          */
 890         suite_ids = xmalloc((num_suites + 1) * sizeof *suite_ids);
 891         br_ssl_client_zero(&cc);
 892         br_ssl_engine_set_versions(&cc.eng, vmin, vmax);
 893         dnhash = NULL;
 894         for (u = 0; hash_functions[u].name; u ++) {
 895                 const br_hash_class *hc;
 896                 int id;
 897
 898                 hc = hash_functions[u].hclass;
 899                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 900                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 901                         dnhash = hc;
 902                 }
 903         }
 904         if (dnhash == NULL) {
 905                 fprintf(stderr, "ERROR: no supported hash function\n");
 906                 goto client_exit_error;
 907         }
 908         br_x509_minimal_init(&xc, dnhash,
 909                 &VEC_ELT(anchors, 0), VEC_LEN(anchors));
 910         if (vmin <= BR_TLS11) {
 911                 if (!(hfuns & (1 << br_md5_ID))) {
 912                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need MD5\n");
 913                         goto client_exit_error;
 914                 }
 915                 if (!(hfuns & (1 << br_sha1_ID))) {
 916                         fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need SHA-1\n");
 917                         goto client_exit_error;
 918                 }
 919         }
 920         for (u = 0; u < num_suites; u ++) {
 921                 unsigned req;
 922
 923                 req = suites[u].req;
 924                 suite_ids[u] = suites[u].suite;
 925                 if ((req & REQ_TLS12) != 0 && vmax < BR_TLS12) {
 926                         fprintf(stderr,
 927                                 "ERROR: cipher suite %s requires TLS 1.2\n",
 928                                 suites[u].name);
 929                         goto client_exit_error;
 930                 }
 931                 if ((req & REQ_SHA1) != 0 && !(hfuns & (1 << br_sha1_ID))) {
 932                         fprintf(stderr,
 933                                 "ERROR: cipher suite %s requires SHA-1\n",
 934                                 suites[u].name);
 935                         goto client_exit_error;
 936                 }
 937                 if ((req & REQ_SHA256) != 0 && !(hfuns & (1 << br_sha256_ID))) {
 938                         fprintf(stderr,
 939                                 "ERROR: cipher suite %s requires SHA-256\n",
 940                                 suites[u].name);
 941                         goto client_exit_error;
 942                 }
 943                 if ((req & REQ_SHA384) != 0 && !(hfuns & (1 << br_sha384_ID))) {
 944                         fprintf(stderr,
 945                                 "ERROR: cipher suite %s requires SHA-384\n",
 946                                 suites[u].name);
 947                         goto client_exit_error;
 948                 }
 949                 /* TODO: algorithm implementation selection */
 950                 if ((req & REQ_AESCBC) != 0) {
 951                         br_ssl_engine_set_default_aes_cbc(&cc.eng);
 952                 }
 953                 if ((req & REQ_AESGCM) != 0) {
 954                         br_ssl_engine_set_default_aes_gcm(&cc.eng);
 955                 }
 956                 if ((req & REQ_CHAPOL) != 0) {
 957                         br_ssl_engine_set_default_chapol(&cc.eng);
 958                 }
 959                 if ((req & REQ_3DESCBC) != 0) {
 960                         br_ssl_engine_set_default_des_cbc(&cc.eng);
 961                 }
 962                 if ((req & REQ_RSAKEYX) != 0) {
 963                         br_ssl_client_set_default_rsapub(&cc);
 964                 }
 965                 if ((req & REQ_ECDHE_RSA) != 0) {
 966                         br_ssl_engine_set_default_ec(&cc.eng);
 967                         br_ssl_engine_set_default_rsavrfy(&cc.eng);
 968                 }
 969                 if ((req & REQ_ECDHE_ECDSA) != 0) {
 970                         br_ssl_engine_set_default_ecdsa(&cc.eng);
 971                 }
 972                 if ((req & REQ_ECDH) != 0) {
 973                         br_ssl_engine_set_default_ec(&cc.eng);
 974                 }
 975         }
 976         if (fallback) {
 977                 suite_ids[num_suites ++] = 0x5600;
 978         }
 979         br_ssl_engine_set_suites(&cc.eng, suite_ids, num_suites);
 980
 981         for (u = 0; hash_functions[u].name; u ++) {
 982                 const br_hash_class *hc;
 983                 int id;
 984
 985                 hc = hash_functions[u].hclass;
 986                 id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
 987                 if ((hfuns & ((unsigned)1 << id)) != 0) {
 988                         br_ssl_engine_set_hash(&cc.eng, id, hc);
 989                         br_x509_minimal_set_hash(&xc, id, hc);
 990                 }
 991         }
 992         if (vmin <= BR_TLS11) {
 993                 br_ssl_engine_set_prf10(&cc.eng, &br_tls10_prf);
 994         }
 995         if (vmax >= BR_TLS12) {
 996                 if ((hfuns & ((unsigned)1 << br_sha256_ID)) != 0) {
 997                         br_ssl_engine_set_prf_sha256(&cc.eng,
 998                                 &br_tls12_sha256_prf);
 999                 }
1000                 if ((hfuns & ((unsigned)1 << br_sha384_ID)) != 0) {
1001                         br_ssl_engine_set_prf_sha384(&cc.eng,
1002                                 &br_tls12_sha384_prf);
1003                 }
1004         }
1005         br_x509_minimal_set_rsa(&xc, br_rsa_pkcs1_vrfy_get_default());
1006         br_x509_minimal_set_ecdsa(&xc,
1007                 br_ec_get_default(), br_ecdsa_vrfy_asn1_get_default());
1008
1009         /*
1010          * If there is no provided trust anchor, then certificate validation
1011          * will always fail. In that situation, we use our custom wrapper
1012          * that tolerates unknown anchors.
1013          */
1014         if (VEC_LEN(anchors) == 0) {
1015                 if (verbose) {
1016                         fprintf(stderr,
1017                                 "WARNING: no configured trust anchor\n");
1018                 }
1019                 x509_noanchor_init(&xwc, &xc.vtable);
1020                 br_ssl_engine_set_x509(&cc.eng, &xwc.vtable);
1021         } else {
1022                 br_ssl_engine_set_x509(&cc.eng, &xc.vtable);
1023         }
1024
1025         if (minhello_len != (size_t)-1) {
1026                 br_ssl_client_set_min_clienthello_len(&cc, minhello_len);
1027         }
1028         br_ssl_engine_set_all_flags(&cc.eng, flags);
1029         if (VEC_LEN(alpn_names) != 0) {
1030                 br_ssl_engine_set_protocol_names(&cc.eng,
1031                         (const char **)&VEC_ELT(alpn_names, 0),
1032                         VEC_LEN(alpn_names));
1033         }
1034
1035         if (chain != NULL) {
1036                 zc.vtable = &ccert_vtable;
1037                 zc.verbose = verbose;
1038                 zc.chain = chain;
1039                 zc.chain_len = chain_len;
1040                 zc.sk = sk;
1041                 if (nostaticecdh || sk->key_type != BR_KEYTYPE_EC) {
1042                         zc.issuer_key_type = 0;
1043                 } else {
1044                         zc.issuer_key_type = get_cert_signer_algo(&chain[0]);
1045                         if (zc.issuer_key_type == 0) {
1046                                 goto client_exit_error;
1047                         }
1048                 }
1049                 br_ssl_client_set_client_certificate(&cc, &zc.vtable);
1050         }
1051
1052         br_ssl_engine_set_buffer(&cc.eng, iobuf, iobuf_len, bidi);
1053         br_ssl_client_reset(&cc, sni, 0);
1054
1055         /*
1056          * On Unix systems, we need to avoid SIGPIPE.
1057          */
1058 #ifndef _WIN32
1059         signal(SIGPIPE, SIG_IGN);
1060 #endif
1061
1062         /*
1063          * Connect to the peer.
1064          */
1065         fd = host_connect(host, port, verbose);
1066         if (fd == INVALID_SOCKET) {
1067                 goto client_exit_error;
1068         }
1069
1070         /*
1071          * Run the engine until completion.
1072          */
1073         if (run_ssl_engine(&cc.eng, fd,
1074                 (verbose ? RUN_ENGINE_VERBOSE : 0)
1075                 | (trace ? RUN_ENGINE_TRACE : 0)) != 0)
1076         {
1077                 goto client_exit_error;
1078         } else {
1079                 goto client_exit;
1080         }
1081
1082         /*
1083          * Release allocated structures.
1084          */
1085 client_exit:
1086         xfree(host);
1087         xfree(port);
1088         xfree(suites);
1089         xfree(suite_ids);
1090         VEC_CLEAREXT(anchors, &free_ta_contents);
1091         VEC_CLEAREXT(alpn_names, &free_alpn);
1092         free_certificates(chain, chain_len);
1093         free_private_key(sk);
1094         xfree(iobuf);
1095         if (fd != INVALID_SOCKET) {
1096 #ifdef _WIN32
1097                 closesocket(fd);
1098 #else
1099                 close(fd);
1100 #endif
1101         }
1102         return retcode;
1103
1104 client_exit_error:
1105         retcode = -1;
1106         goto client_exit;
1107 }