1 /* $OpenBSD: tls_client.c,v 1.44 2018/02/10 04:41:24 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 ((ctx = tls_new()) == NULL) 42 return (NULL); 43 44 ctx->flags |= TLS_CLIENT; 45 46 return (ctx); 47 } 48 49 int 50 tls_connect(struct tls *ctx, const char *host, const char *port) 51 { 52 return tls_connect_servername(ctx, host, port, NULL); 53 } 54 55 int 56 tls_connect_servername(struct tls *ctx, const char *host, const char *port, 57 const char *servername) 58 { 59 struct addrinfo hints, *res, *res0; 60 const char *h = NULL, *p = NULL; 61 char *hs = NULL, *ps = NULL; 62 int rv = -1, s = -1, ret; 63 64 if ((ctx->flags & TLS_CLIENT) == 0) { 65 tls_set_errorx(ctx, "not a client context"); 66 goto err; 67 } 68 69 if (host == NULL) { 70 tls_set_errorx(ctx, "host not specified"); 71 goto err; 72 } 73 74 /* 75 * If port is NULL try to extract a port from the specified host, 76 * otherwise use the default. 77 */ 78 if ((p = (char *)port) == NULL) { 79 ret = tls_host_port(host, &hs, &ps); 80 if (ret == -1) { 81 tls_set_errorx(ctx, "memory allocation failure"); 82 goto err; 83 } 84 if (ret != 0) { 85 tls_set_errorx(ctx, "no port provided"); 86 goto err; 87 } 88 } 89 90 h = (hs != NULL) ? hs : host; 91 p = (ps != NULL) ? ps : port; 92 93 /* 94 * First check if the host is specified as a numeric IP address, 95 * either IPv4 or IPv6, before trying to resolve the host. 96 * The AI_ADDRCONFIG resolver option will not return IPv4 or IPv6 97 * records if it is not configured on an interface; not considering 98 * loopback addresses. Checking the numeric addresses first makes 99 * sure that connection attempts to numeric addresses and especially 100 * 127.0.0.1 or ::1 loopback addresses are always possible. 101 */ 102 memset(&hints, 0, sizeof(hints)); 103 hints.ai_socktype = SOCK_STREAM; 104 105 /* try as an IPv4 literal */ 106 hints.ai_family = AF_INET; 107 hints.ai_flags = AI_NUMERICHOST; 108 if (getaddrinfo(h, p, &hints, &res0) != 0) { 109 /* try again as an IPv6 literal */ 110 hints.ai_family = AF_INET6; 111 if (getaddrinfo(h, p, &hints, &res0) != 0) { 112 /* last try, with name resolution and save the error */ 113 hints.ai_family = AF_UNSPEC; 114 hints.ai_flags = AI_ADDRCONFIG; 115 if ((s = getaddrinfo(h, p, &hints, &res0)) != 0) { 116 tls_set_error(ctx, "%s", gai_strerror(s)); 117 goto err; 118 } 119 } 120 } 121 122 /* It was resolved somehow; now try connecting to what we got */ 123 s = -1; 124 for (res = res0; res; res = res->ai_next) { 125 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); 126 if (s == -1) { 127 tls_set_error(ctx, "socket"); 128 continue; 129 } 130 if (connect(s, res->ai_addr, res->ai_addrlen) == -1) { 131 tls_set_error(ctx, "connect"); 132 close(s); 133 s = -1; 134 continue; 135 } 136 137 break; /* Connected. */ 138 } 139 freeaddrinfo(res0); 140 141 if (s == -1) 142 goto err; 143 144 if (servername == NULL) 145 servername = h; 146 147 if (tls_connect_socket(ctx, s, servername) != 0) { 148 close(s); 149 goto err; 150 } 151 152 ctx->socket = s; 153 154 rv = 0; 155 156 err: 157 free(hs); 158 free(ps); 159 160 return (rv); 161 } 162 163 static int 164 tls_client_read_session(struct tls *ctx) 165 { 166 int sfd = ctx->config->session_fd; 167 uint8_t *session = NULL; 168 size_t session_len = 0; 169 SSL_SESSION *ss = NULL; 170 BIO *bio = NULL; 171 struct stat sb; 172 ssize_t n; 173 int rv = -1; 174 175 if (fstat(sfd, &sb) == -1) { 176 tls_set_error(ctx, "failed to stat session file"); 177 goto err; 178 } 179 if (sb.st_size < 0 || sb.st_size > INT_MAX) { 180 tls_set_errorx(ctx, "invalid session file size"); 181 goto err; 182 } 183 session_len = (size_t)sb.st_size; 184 185 /* A zero size file means that we do not yet have a valid session. */ 186 if (session_len == 0) 187 goto done; 188 189 if ((session = malloc(session_len)) == NULL) 190 goto err; 191 192 n = pread(sfd, session, session_len, 0); 193 if (n < 0 || (size_t)n != session_len) { 194 tls_set_error(ctx, "failed to read session file"); 195 goto err; 196 } 197 if ((bio = BIO_new_mem_buf(session, session_len)) == NULL) 198 goto err; 199 if ((ss = PEM_read_bio_SSL_SESSION(bio, NULL, tls_password_cb, 200 NULL)) == NULL) { 201 tls_set_errorx(ctx, "failed to parse session"); 202 goto err; 203 } 204 205 if (SSL_set_session(ctx->ssl_conn, ss) != 1) { 206 tls_set_errorx(ctx, "failed to set session"); 207 goto err; 208 } 209 210 done: 211 rv = 0; 212 213 err: 214 freezero(session, session_len); 215 SSL_SESSION_free(ss); 216 BIO_free(bio); 217 218 return rv; 219 } 220 221 static int 222 tls_client_write_session(struct tls *ctx) 223 { 224 int sfd = ctx->config->session_fd; 225 SSL_SESSION *ss = NULL; 226 BIO *bio = NULL; 227 long data_len; 228 char *data; 229 off_t offset; 230 size_t len; 231 ssize_t n; 232 int rv = -1; 233 234 if ((ss = SSL_get1_session(ctx->ssl_conn)) == NULL) { 235 if (ftruncate(sfd, 0) == -1) { 236 tls_set_error(ctx, "failed to truncate session file"); 237 goto err; 238 } 239 goto done; 240 } 241 242 if ((bio = BIO_new(BIO_s_mem())) == NULL) 243 goto err; 244 if (PEM_write_bio_SSL_SESSION(bio, ss) == 0) 245 goto err; 246 if ((data_len = BIO_get_mem_data(bio, &data)) <= 0) 247 goto err; 248 249 len = (size_t)data_len; 250 offset = 0; 251 252 if (ftruncate(sfd, len) == -1) { 253 tls_set_error(ctx, "failed to truncate session file"); 254 goto err; 255 } 256 while (len > 0) { 257 if ((n = pwrite(sfd, data + offset, len, offset)) == -1) { 258 tls_set_error(ctx, "failed to write session file"); 259 goto err; 260 } 261 offset += n; 262 len -= n; 263 } 264 265 done: 266 rv = 0; 267 268 err: 269 SSL_SESSION_free(ss); 270 BIO_free_all(bio); 271 272 return (rv); 273 } 274 275 static int 276 tls_connect_common(struct tls *ctx, const char *servername) 277 { 278 union tls_addr addrbuf; 279 int rv = -1; 280 281 if ((ctx->flags & TLS_CLIENT) == 0) { 282 tls_set_errorx(ctx, "not a client context"); 283 goto err; 284 } 285 286 if (servername != NULL) { 287 if ((ctx->servername = strdup(servername)) == NULL) { 288 tls_set_errorx(ctx, "out of memory"); 289 goto err; 290 } 291 } 292 293 if ((ctx->ssl_ctx = SSL_CTX_new(SSLv23_client_method())) == NULL) { 294 tls_set_errorx(ctx, "ssl context failure"); 295 goto err; 296 } 297 298 if (tls_configure_ssl(ctx, ctx->ssl_ctx) != 0) 299 goto err; 300 301 if (tls_configure_ssl_keypair(ctx, ctx->ssl_ctx, 302 ctx->config->keypair, 0) != 0) 303 goto err; 304 305 if (ctx->config->verify_name) { 306 if (servername == NULL) { 307 tls_set_errorx(ctx, "server name not specified"); 308 goto err; 309 } 310 } 311 312 if (tls_configure_ssl_verify(ctx, ctx->ssl_ctx, SSL_VERIFY_PEER) == -1) 313 goto err; 314 315 if (ctx->config->ecdhecurves != NULL) { 316 if (SSL_CTX_set1_groups(ctx->ssl_ctx, ctx->config->ecdhecurves, 317 ctx->config->ecdhecurves_len) != 1) { 318 tls_set_errorx(ctx, "failed to set ecdhe curves"); 319 goto err; 320 } 321 } 322 323 if (SSL_CTX_set_tlsext_status_cb(ctx->ssl_ctx, tls_ocsp_verify_cb) != 1) { 324 tls_set_errorx(ctx, "ssl OCSP verification setup failure"); 325 goto err; 326 } 327 328 if ((ctx->ssl_conn = SSL_new(ctx->ssl_ctx)) == NULL) { 329 tls_set_errorx(ctx, "ssl connection failure"); 330 goto err; 331 } 332 333 if (SSL_set_app_data(ctx->ssl_conn, ctx) != 1) { 334 tls_set_errorx(ctx, "ssl application data failure"); 335 goto err; 336 } 337 338 if (ctx->config->session_fd != -1) { 339 SSL_clear_options(ctx->ssl_conn, SSL_OP_NO_TICKET); 340 if (tls_client_read_session(ctx) == -1) 341 goto err; 342 } 343 344 if (SSL_set_tlsext_status_type(ctx->ssl_conn, TLSEXT_STATUSTYPE_ocsp) != 1) { 345 tls_set_errorx(ctx, "ssl OCSP extension setup failure"); 346 goto err; 347 } 348 349 /* 350 * RFC4366 (SNI): Literal IPv4 and IPv6 addresses are not 351 * permitted in "HostName". 352 */ 353 if (servername != NULL && 354 inet_pton(AF_INET, servername, &addrbuf) != 1 && 355 inet_pton(AF_INET6, servername, &addrbuf) != 1) { 356 if (SSL_set_tlsext_host_name(ctx->ssl_conn, servername) == 0) { 357 tls_set_errorx(ctx, "server name indication failure"); 358 goto err; 359 } 360 } 361 362 ctx->state |= TLS_CONNECTED; 363 rv = 0; 364 365 err: 366 return (rv); 367 } 368 369 int 370 tls_connect_socket(struct tls *ctx, int s, const char *servername) 371 { 372 return tls_connect_fds(ctx, s, s, servername); 373 } 374 375 int 376 tls_connect_fds(struct tls *ctx, int fd_read, int fd_write, 377 const char *servername) 378 { 379 int rv = -1; 380 381 if (fd_read < 0 || fd_write < 0) { 382 tls_set_errorx(ctx, "invalid file descriptors"); 383 goto err; 384 } 385 386 if (tls_connect_common(ctx, servername) != 0) 387 goto err; 388 389 if (SSL_set_rfd(ctx->ssl_conn, fd_read) != 1 || 390 SSL_set_wfd(ctx->ssl_conn, fd_write) != 1) { 391 tls_set_errorx(ctx, "ssl file descriptor failure"); 392 goto err; 393 } 394 395 rv = 0; 396 err: 397 return (rv); 398 } 399 400 int 401 tls_connect_cbs(struct tls *ctx, tls_read_cb read_cb, 402 tls_write_cb write_cb, void *cb_arg, const char *servername) 403 { 404 int rv = -1; 405 406 if (tls_connect_common(ctx, servername) != 0) 407 goto err; 408 409 if (tls_set_cbs(ctx, read_cb, write_cb, cb_arg) != 0) 410 goto err; 411 412 rv = 0; 413 414 err: 415 return (rv); 416 } 417 418 int 419 tls_handshake_client(struct tls *ctx) 420 { 421 X509 *cert = NULL; 422 int match, ssl_ret; 423 int rv = -1; 424 425 if ((ctx->flags & TLS_CLIENT) == 0) { 426 tls_set_errorx(ctx, "not a client context"); 427 goto err; 428 } 429 430 if ((ctx->state & TLS_CONNECTED) == 0) { 431 tls_set_errorx(ctx, "context not connected"); 432 goto err; 433 } 434 435 ctx->state |= TLS_SSL_NEEDS_SHUTDOWN; 436 437 ERR_clear_error(); 438 if ((ssl_ret = SSL_connect(ctx->ssl_conn)) != 1) { 439 rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "handshake"); 440 goto err; 441 } 442 443 if (ctx->config->verify_name) { 444 cert = SSL_get_peer_certificate(ctx->ssl_conn); 445 if (cert == NULL) { 446 tls_set_errorx(ctx, "no server certificate"); 447 goto err; 448 } 449 if (tls_check_name(ctx, cert, ctx->servername, &match) == -1) 450 goto err; 451 if (!match) { 452 tls_set_errorx(ctx, "name `%s' not present in" 453 " server certificate", ctx->servername); 454 goto err; 455 } 456 } 457 458 ctx->state |= TLS_HANDSHAKE_COMPLETE; 459 460 if (ctx->config->session_fd != -1) { 461 if (tls_client_write_session(ctx) == -1) 462 goto err; 463 } 464 465 rv = 0; 466 467 err: 468 X509_free(cert); 469 470 return (rv); 471 } 472