1 /* $OpenBSD: tls_client.c,v 1.45 2018/03/19 16:34:47 jsing Exp $ */ 2 /* 3 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <sys/types.h> 19 #include <sys/socket.h> 20 #include <sys/stat.h> 21 22 #include <arpa/inet.h> 23 #include <netinet/in.h> 24 25 #include <limits.h> 26 #include <netdb.h> 27 #include <stdlib.h> 28 #include <unistd.h> 29 30 #include <openssl/err.h> 31 #include <openssl/x509.h> 32 33 #include <tls.h> 34 #include "tls_internal.h" 35 36 struct tls * 37 tls_client(void) 38 { 39 struct tls *ctx; 40 41 if (tls_init() == -1) 42 return (NULL); 43 44 if ((ctx = tls_new()) == NULL) 45 return (NULL); 46 47 ctx->flags |= TLS_CLIENT; 48 49 return (ctx); 50 } 51 52 int 53 tls_connect(struct tls *ctx, const char *host, const char *port) 54 { 55 return tls_connect_servername(ctx, host, port, NULL); 56 } 57 58 int 59 tls_connect_servername(struct tls *ctx, const char *host, const char *port, 60 const char *servername) 61 { 62 struct addrinfo hints, *res, *res0; 63 const char *h = NULL, *p = NULL; 64 char *hs = NULL, *ps = NULL; 65 int rv = -1, s = -1, ret; 66 67 if ((ctx->flags & TLS_CLIENT) == 0) { 68 tls_set_errorx(ctx, "not a client context"); 69 goto err; 70 } 71 72 if (host == NULL) { 73 tls_set_errorx(ctx, "host not specified"); 74 goto err; 75 } 76 77 /* 78 * If port is NULL try to extract a port from the specified host, 79 * otherwise use the default. 80 */ 81 if ((p = (char *)port) == NULL) { 82 ret = tls_host_port(host, &hs, &ps); 83 if (ret == -1) { 84 tls_set_errorx(ctx, "memory allocation failure"); 85 goto err; 86 } 87 if (ret != 0) { 88 tls_set_errorx(ctx, "no port provided"); 89 goto err; 90 } 91 } 92 93 h = (hs != NULL) ? hs : host; 94 p = (ps != NULL) ? ps : port; 95 96 /* 97 * First check if the host is specified as a numeric IP address, 98 * either IPv4 or IPv6, before trying to resolve the host. 99 * The AI_ADDRCONFIG resolver option will not return IPv4 or IPv6 100 * records if it is not configured on an interface; not considering 101 * loopback addresses. Checking the numeric addresses first makes 102 * sure that connection attempts to numeric addresses and especially 103 * 127.0.0.1 or ::1 loopback addresses are always possible. 104 */ 105 memset(&hints, 0, sizeof(hints)); 106 hints.ai_socktype = SOCK_STREAM; 107 108 /* try as an IPv4 literal */ 109 hints.ai_family = AF_INET; 110 hints.ai_flags = AI_NUMERICHOST; 111 if (getaddrinfo(h, p, &hints, &res0) != 0) { 112 /* try again as an IPv6 literal */ 113 hints.ai_family = AF_INET6; 114 if (getaddrinfo(h, p, &hints, &res0) != 0) { 115 /* last try, with name resolution and save the error */ 116 hints.ai_family = AF_UNSPEC; 117 hints.ai_flags = AI_ADDRCONFIG; 118 if ((s = getaddrinfo(h, p, &hints, &res0)) != 0) { 119 tls_set_error(ctx, "%s", gai_strerror(s)); 120 goto err; 121 } 122 } 123 } 124 125 /* It was resolved somehow; now try connecting to what we got */ 126 s = -1; 127 for (res = res0; res; res = res->ai_next) { 128 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); 129 if (s == -1) { 130 tls_set_error(ctx, "socket"); 131 continue; 132 } 133 if (connect(s, res->ai_addr, res->ai_addrlen) == -1) { 134 tls_set_error(ctx, "connect"); 135 close(s); 136 s = -1; 137 continue; 138 } 139 140 break; /* Connected. */ 141 } 142 freeaddrinfo(res0); 143 144 if (s == -1) 145 goto err; 146 147 if (servername == NULL) 148 servername = h; 149 150 if (tls_connect_socket(ctx, s, servername) != 0) { 151 close(s); 152 goto err; 153 } 154 155 ctx->socket = s; 156 157 rv = 0; 158 159 err: 160 free(hs); 161 free(ps); 162 163 return (rv); 164 } 165 166 static int 167 tls_client_read_session(struct tls *ctx) 168 { 169 int sfd = ctx->config->session_fd; 170 uint8_t *session = NULL; 171 size_t session_len = 0; 172 SSL_SESSION *ss = NULL; 173 BIO *bio = NULL; 174 struct stat sb; 175 ssize_t n; 176 int rv = -1; 177 178 if (fstat(sfd, &sb) == -1) { 179 tls_set_error(ctx, "failed to stat session file"); 180 goto err; 181 } 182 if (sb.st_size < 0 || sb.st_size > INT_MAX) { 183 tls_set_errorx(ctx, "invalid session file size"); 184 goto err; 185 } 186 session_len = (size_t)sb.st_size; 187 188 /* A zero size file means that we do not yet have a valid session. */ 189 if (session_len == 0) 190 goto done; 191 192 if ((session = malloc(session_len)) == NULL) 193 goto err; 194 195 n = pread(sfd, session, session_len, 0); 196 if (n < 0 || (size_t)n != session_len) { 197 tls_set_error(ctx, "failed to read session file"); 198 goto err; 199 } 200 if ((bio = BIO_new_mem_buf(session, session_len)) == NULL) 201 goto err; 202 if ((ss = PEM_read_bio_SSL_SESSION(bio, NULL, tls_password_cb, 203 NULL)) == NULL) { 204 tls_set_errorx(ctx, "failed to parse session"); 205 goto err; 206 } 207 208 if (SSL_set_session(ctx->ssl_conn, ss) != 1) { 209 tls_set_errorx(ctx, "failed to set session"); 210 goto err; 211 } 212 213 done: 214 rv = 0; 215 216 err: 217 freezero(session, session_len); 218 SSL_SESSION_free(ss); 219 BIO_free(bio); 220 221 return rv; 222 } 223 224 static int 225 tls_client_write_session(struct tls *ctx) 226 { 227 int sfd = ctx->config->session_fd; 228 SSL_SESSION *ss = NULL; 229 BIO *bio = NULL; 230 long data_len; 231 char *data; 232 off_t offset; 233 size_t len; 234 ssize_t n; 235 int rv = -1; 236 237 if ((ss = SSL_get1_session(ctx->ssl_conn)) == NULL) { 238 if (ftruncate(sfd, 0) == -1) { 239 tls_set_error(ctx, "failed to truncate session file"); 240 goto err; 241 } 242 goto done; 243 } 244 245 if ((bio = BIO_new(BIO_s_mem())) == NULL) 246 goto err; 247 if (PEM_write_bio_SSL_SESSION(bio, ss) == 0) 248 goto err; 249 if ((data_len = BIO_get_mem_data(bio, &data)) <= 0) 250 goto err; 251 252 len = (size_t)data_len; 253 offset = 0; 254 255 if (ftruncate(sfd, len) == -1) { 256 tls_set_error(ctx, "failed to truncate session file"); 257 goto err; 258 } 259 while (len > 0) { 260 if ((n = pwrite(sfd, data + offset, len, offset)) == -1) { 261 tls_set_error(ctx, "failed to write session file"); 262 goto err; 263 } 264 offset += n; 265 len -= n; 266 } 267 268 done: 269 rv = 0; 270 271 err: 272 SSL_SESSION_free(ss); 273 BIO_free_all(bio); 274 275 return (rv); 276 } 277 278 static int 279 tls_connect_common(struct tls *ctx, const char *servername) 280 { 281 union tls_addr addrbuf; 282 int rv = -1; 283 284 if ((ctx->flags & TLS_CLIENT) == 0) { 285 tls_set_errorx(ctx, "not a client context"); 286 goto err; 287 } 288 289 if (servername != NULL) { 290 if ((ctx->servername = strdup(servername)) == NULL) { 291 tls_set_errorx(ctx, "out of memory"); 292 goto err; 293 } 294 } 295 296 if ((ctx->ssl_ctx = SSL_CTX_new(SSLv23_client_method())) == NULL) { 297 tls_set_errorx(ctx, "ssl context failure"); 298 goto err; 299 } 300 301 if (tls_configure_ssl(ctx, ctx->ssl_ctx) != 0) 302 goto err; 303 304 if (tls_configure_ssl_keypair(ctx, ctx->ssl_ctx, 305 ctx->config->keypair, 0) != 0) 306 goto err; 307 308 if (ctx->config->verify_name) { 309 if (servername == NULL) { 310 tls_set_errorx(ctx, "server name not specified"); 311 goto err; 312 } 313 } 314 315 if (tls_configure_ssl_verify(ctx, ctx->ssl_ctx, SSL_VERIFY_PEER) == -1) 316 goto err; 317 318 if (ctx->config->ecdhecurves != NULL) { 319 if (SSL_CTX_set1_groups(ctx->ssl_ctx, ctx->config->ecdhecurves, 320 ctx->config->ecdhecurves_len) != 1) { 321 tls_set_errorx(ctx, "failed to set ecdhe curves"); 322 goto err; 323 } 324 } 325 326 if (SSL_CTX_set_tlsext_status_cb(ctx->ssl_ctx, tls_ocsp_verify_cb) != 1) { 327 tls_set_errorx(ctx, "ssl OCSP verification setup failure"); 328 goto err; 329 } 330 331 if ((ctx->ssl_conn = SSL_new(ctx->ssl_ctx)) == NULL) { 332 tls_set_errorx(ctx, "ssl connection failure"); 333 goto err; 334 } 335 336 if (SSL_set_app_data(ctx->ssl_conn, ctx) != 1) { 337 tls_set_errorx(ctx, "ssl application data failure"); 338 goto err; 339 } 340 341 if (ctx->config->session_fd != -1) { 342 SSL_clear_options(ctx->ssl_conn, SSL_OP_NO_TICKET); 343 if (tls_client_read_session(ctx) == -1) 344 goto err; 345 } 346 347 if (SSL_set_tlsext_status_type(ctx->ssl_conn, TLSEXT_STATUSTYPE_ocsp) != 1) { 348 tls_set_errorx(ctx, "ssl OCSP extension setup failure"); 349 goto err; 350 } 351 352 /* 353 * RFC4366 (SNI): Literal IPv4 and IPv6 addresses are not 354 * permitted in "HostName". 355 */ 356 if (servername != NULL && 357 inet_pton(AF_INET, servername, &addrbuf) != 1 && 358 inet_pton(AF_INET6, servername, &addrbuf) != 1) { 359 if (SSL_set_tlsext_host_name(ctx->ssl_conn, servername) == 0) { 360 tls_set_errorx(ctx, "server name indication failure"); 361 goto err; 362 } 363 } 364 365 ctx->state |= TLS_CONNECTED; 366 rv = 0; 367 368 err: 369 return (rv); 370 } 371 372 int 373 tls_connect_socket(struct tls *ctx, int s, const char *servername) 374 { 375 return tls_connect_fds(ctx, s, s, servername); 376 } 377 378 int 379 tls_connect_fds(struct tls *ctx, int fd_read, int fd_write, 380 const char *servername) 381 { 382 int rv = -1; 383 384 if (fd_read < 0 || fd_write < 0) { 385 tls_set_errorx(ctx, "invalid file descriptors"); 386 goto err; 387 } 388 389 if (tls_connect_common(ctx, servername) != 0) 390 goto err; 391 392 if (SSL_set_rfd(ctx->ssl_conn, fd_read) != 1 || 393 SSL_set_wfd(ctx->ssl_conn, fd_write) != 1) { 394 tls_set_errorx(ctx, "ssl file descriptor failure"); 395 goto err; 396 } 397 398 rv = 0; 399 err: 400 return (rv); 401 } 402 403 int 404 tls_connect_cbs(struct tls *ctx, tls_read_cb read_cb, 405 tls_write_cb write_cb, void *cb_arg, const char *servername) 406 { 407 int rv = -1; 408 409 if (tls_connect_common(ctx, servername) != 0) 410 goto err; 411 412 if (tls_set_cbs(ctx, read_cb, write_cb, cb_arg) != 0) 413 goto err; 414 415 rv = 0; 416 417 err: 418 return (rv); 419 } 420 421 int 422 tls_handshake_client(struct tls *ctx) 423 { 424 X509 *cert = NULL; 425 int match, ssl_ret; 426 int rv = -1; 427 428 if ((ctx->flags & TLS_CLIENT) == 0) { 429 tls_set_errorx(ctx, "not a client context"); 430 goto err; 431 } 432 433 if ((ctx->state & TLS_CONNECTED) == 0) { 434 tls_set_errorx(ctx, "context not connected"); 435 goto err; 436 } 437 438 ctx->state |= TLS_SSL_NEEDS_SHUTDOWN; 439 440 ERR_clear_error(); 441 if ((ssl_ret = SSL_connect(ctx->ssl_conn)) != 1) { 442 rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "handshake"); 443 goto err; 444 } 445 446 if (ctx->config->verify_name) { 447 cert = SSL_get_peer_certificate(ctx->ssl_conn); 448 if (cert == NULL) { 449 tls_set_errorx(ctx, "no server certificate"); 450 goto err; 451 } 452 if (tls_check_name(ctx, cert, ctx->servername, &match) == -1) 453 goto err; 454 if (!match) { 455 tls_set_errorx(ctx, "name `%s' not present in" 456 " server certificate", ctx->servername); 457 goto err; 458 } 459 } 460 461 ctx->state |= TLS_HANDSHAKE_COMPLETE; 462 463 if (ctx->config->session_fd != -1) { 464 if (tls_client_write_session(ctx) == -1) 465 goto err; 466 } 467 468 rv = 0; 469 470 err: 471 X509_free(cert); 472 473 return (rv); 474 } 475