1 /*- 2 * Copyright (c) 2011 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Pawel Jakub Dawidek under sponsorship from 6 * the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <config/config.h> 31 32 #include <sys/param.h> /* MAXHOSTNAMELEN */ 33 #include <sys/socket.h> 34 35 #include <arpa/inet.h> 36 37 #include <netinet/in.h> 38 #include <netinet/tcp.h> 39 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <netdb.h> 43 #include <signal.h> 44 #include <stdbool.h> 45 #include <stdint.h> 46 #include <stdio.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #include <openssl/err.h> 51 #include <openssl/ssl.h> 52 53 #include <compat/compat.h> 54 #ifndef HAVE_CLOSEFROM 55 #include <compat/closefrom.h> 56 #endif 57 #ifndef HAVE_STRLCPY 58 #include <compat/strlcpy.h> 59 #endif 60 61 #include "pjdlog.h" 62 #include "proto_impl.h" 63 #include "sandbox.h" 64 #include "subr.h" 65 66 #define TLS_CTX_MAGIC 0x715c7 67 struct tls_ctx { 68 int tls_magic; 69 struct proto_conn *tls_sock; 70 struct proto_conn *tls_tcp; 71 char tls_laddr[256]; 72 char tls_raddr[256]; 73 int tls_side; 74 #define TLS_SIDE_CLIENT 0 75 #define TLS_SIDE_SERVER_LISTEN 1 76 #define TLS_SIDE_SERVER_WORK 2 77 bool tls_wait_called; 78 }; 79 80 #define TLS_DEFAULT_TIMEOUT 30 81 82 static int tls_connect_wait(void *ctx, int timeout); 83 static void tls_close(void *ctx); 84 85 static void 86 block(int fd) 87 { 88 int flags; 89 90 flags = fcntl(fd, F_GETFL); 91 if (flags == -1) 92 pjdlog_exit(EX_TEMPFAIL, "fcntl(F_GETFL) failed"); 93 flags &= ~O_NONBLOCK; 94 if (fcntl(fd, F_SETFL, flags) == -1) 95 pjdlog_exit(EX_TEMPFAIL, "fcntl(F_SETFL) failed"); 96 } 97 98 static void 99 nonblock(int fd) 100 { 101 int flags; 102 103 flags = fcntl(fd, F_GETFL); 104 if (flags == -1) 105 pjdlog_exit(EX_TEMPFAIL, "fcntl(F_GETFL) failed"); 106 flags |= O_NONBLOCK; 107 if (fcntl(fd, F_SETFL, flags) == -1) 108 pjdlog_exit(EX_TEMPFAIL, "fcntl(F_SETFL) failed"); 109 } 110 111 static int 112 wait_for_fd(int fd, int timeout) 113 { 114 struct timeval tv; 115 fd_set fdset; 116 int error, ret; 117 118 error = 0; 119 120 for (;;) { 121 FD_ZERO(&fdset); 122 FD_SET(fd, &fdset); 123 124 tv.tv_sec = timeout; 125 tv.tv_usec = 0; 126 127 ret = select(fd + 1, NULL, &fdset, NULL, 128 timeout == -1 ? NULL : &tv); 129 if (ret == 0) { 130 error = ETIMEDOUT; 131 break; 132 } else if (ret == -1) { 133 if (errno == EINTR) 134 continue; 135 error = errno; 136 break; 137 } 138 PJDLOG_ASSERT(ret > 0); 139 PJDLOG_ASSERT(FD_ISSET(fd, &fdset)); 140 break; 141 } 142 143 return (error); 144 } 145 146 static void 147 ssl_log_errors(void) 148 { 149 unsigned long error; 150 151 while ((error = ERR_get_error()) != 0) 152 pjdlog_error("SSL error: %s", ERR_error_string(error, NULL)); 153 } 154 155 static int 156 ssl_check_error(SSL *ssl, int ret) 157 { 158 int error; 159 160 error = SSL_get_error(ssl, ret); 161 162 switch (error) { 163 case SSL_ERROR_NONE: 164 return (0); 165 case SSL_ERROR_WANT_READ: 166 pjdlog_debug(2, "SSL_ERROR_WANT_READ"); 167 return (-1); 168 case SSL_ERROR_WANT_WRITE: 169 pjdlog_debug(2, "SSL_ERROR_WANT_WRITE"); 170 return (-1); 171 case SSL_ERROR_ZERO_RETURN: 172 pjdlog_exitx(EX_OK, "Connection closed."); 173 case SSL_ERROR_SYSCALL: 174 ssl_log_errors(); 175 pjdlog_exitx(EX_TEMPFAIL, "SSL I/O error."); 176 case SSL_ERROR_SSL: 177 ssl_log_errors(); 178 pjdlog_exitx(EX_TEMPFAIL, "SSL protocol error."); 179 default: 180 ssl_log_errors(); 181 pjdlog_exitx(EX_TEMPFAIL, "Unknown SSL error (%d).", error); 182 } 183 } 184 185 static void 186 tcp_recv_ssl_send(int recvfd, SSL *sendssl) 187 { 188 static unsigned char buf[65536]; 189 ssize_t tcpdone; 190 int sendfd, ssldone; 191 192 sendfd = SSL_get_fd(sendssl); 193 PJDLOG_ASSERT(sendfd >= 0); 194 pjdlog_debug(2, "%s: start %d -> %d", __func__, recvfd, sendfd); 195 for (;;) { 196 tcpdone = recv(recvfd, buf, sizeof(buf), 0); 197 pjdlog_debug(2, "%s: recv() returned %zd", __func__, tcpdone); 198 if (tcpdone == 0) { 199 pjdlog_debug(1, "Connection terminated."); 200 exit(0); 201 } else if (tcpdone == -1) { 202 if (errno == EINTR) 203 continue; 204 else if (errno == EAGAIN) 205 break; 206 pjdlog_exit(EX_TEMPFAIL, "recv() failed"); 207 } 208 for (;;) { 209 ssldone = SSL_write(sendssl, buf, (int)tcpdone); 210 pjdlog_debug(2, "%s: send() returned %d", __func__, 211 ssldone); 212 if (ssl_check_error(sendssl, ssldone) == -1) { 213 (void)wait_for_fd(sendfd, -1); 214 continue; 215 } 216 PJDLOG_ASSERT(ssldone == tcpdone); 217 break; 218 } 219 } 220 pjdlog_debug(2, "%s: done %d -> %d", __func__, recvfd, sendfd); 221 } 222 223 static void 224 ssl_recv_tcp_send(SSL *recvssl, int sendfd) 225 { 226 static unsigned char buf[65536]; 227 unsigned char *ptr; 228 ssize_t tcpdone; 229 size_t todo; 230 int recvfd, ssldone; 231 232 recvfd = SSL_get_fd(recvssl); 233 PJDLOG_ASSERT(recvfd >= 0); 234 pjdlog_debug(2, "%s: start %d -> %d", __func__, recvfd, sendfd); 235 for (;;) { 236 ssldone = SSL_read(recvssl, buf, sizeof(buf)); 237 pjdlog_debug(2, "%s: SSL_read() returned %d", __func__, 238 ssldone); 239 if (ssl_check_error(recvssl, ssldone) == -1) 240 break; 241 todo = (size_t)ssldone; 242 ptr = buf; 243 do { 244 tcpdone = send(sendfd, ptr, todo, MSG_NOSIGNAL); 245 pjdlog_debug(2, "%s: send() returned %zd", __func__, 246 tcpdone); 247 if (tcpdone == 0) { 248 pjdlog_debug(1, "Connection terminated."); 249 exit(0); 250 } else if (tcpdone == -1) { 251 if (errno == EINTR || errno == ENOBUFS) 252 continue; 253 if (errno == EAGAIN) { 254 (void)wait_for_fd(sendfd, -1); 255 continue; 256 } 257 pjdlog_exit(EX_TEMPFAIL, "send() failed"); 258 } 259 todo -= tcpdone; 260 ptr += tcpdone; 261 } while (todo > 0); 262 } 263 pjdlog_debug(2, "%s: done %d -> %d", __func__, recvfd, sendfd); 264 } 265 266 static void 267 tls_loop(int sockfd, SSL *tcpssl) 268 { 269 fd_set fds; 270 int maxfd, tcpfd; 271 272 tcpfd = SSL_get_fd(tcpssl); 273 PJDLOG_ASSERT(tcpfd >= 0); 274 275 for (;;) { 276 FD_ZERO(&fds); 277 FD_SET(sockfd, &fds); 278 FD_SET(tcpfd, &fds); 279 maxfd = MAX(sockfd, tcpfd); 280 281 PJDLOG_ASSERT(maxfd + 1 <= (int)FD_SETSIZE); 282 if (select(maxfd + 1, &fds, NULL, NULL, NULL) == -1) { 283 if (errno == EINTR) 284 continue; 285 pjdlog_exit(EX_TEMPFAIL, "select() failed"); 286 } 287 if (FD_ISSET(sockfd, &fds)) 288 tcp_recv_ssl_send(sockfd, tcpssl); 289 if (FD_ISSET(tcpfd, &fds)) 290 ssl_recv_tcp_send(tcpssl, sockfd); 291 } 292 } 293 294 static void 295 tls_certificate_verify(SSL *ssl, const char *fingerprint) 296 { 297 unsigned char md[EVP_MAX_MD_SIZE]; 298 char mdstr[sizeof("SHA256=") - 1 + EVP_MAX_MD_SIZE * 3]; 299 char *mdstrp; 300 unsigned int i, mdsize; 301 X509 *cert; 302 303 if (fingerprint[0] == '\0') { 304 pjdlog_debug(1, "No fingerprint verification requested."); 305 return; 306 } 307 308 cert = SSL_get_peer_certificate(ssl); 309 if (cert == NULL) 310 pjdlog_exitx(EX_TEMPFAIL, "No peer certificate received."); 311 312 if (X509_digest(cert, EVP_sha256(), md, &mdsize) != 1) 313 pjdlog_exitx(EX_TEMPFAIL, "X509_digest() failed."); 314 PJDLOG_ASSERT(mdsize <= EVP_MAX_MD_SIZE); 315 316 X509_free(cert); 317 318 (void)strlcpy(mdstr, "SHA256=", sizeof(mdstr)); 319 mdstrp = mdstr + strlen(mdstr); 320 for (i = 0; i < mdsize; i++) { 321 PJDLOG_VERIFY(mdstrp + 3 <= mdstr + sizeof(mdstr)); 322 (void)sprintf(mdstrp, "%02hhX:", md[i]); 323 mdstrp += 3; 324 } 325 /* Clear last colon. */ 326 mdstrp[-1] = '\0'; 327 if (strcasecmp(mdstr, fingerprint) != 0) { 328 pjdlog_exitx(EX_NOPERM, 329 "Finger print doesn't match. Received \"%s\", expected \"%s\"", 330 mdstr, fingerprint); 331 } 332 } 333 334 static void 335 tls_exec_client(const char *user, int startfd, const char *srcaddr, 336 const char *dstaddr, const char *fingerprint, const char *defport, 337 int timeout, int debuglevel) 338 { 339 struct proto_conn *tcp; 340 char *saddr, *daddr; 341 SSL_CTX *sslctx; 342 SSL *ssl; 343 long ret; 344 int sockfd, tcpfd; 345 uint8_t connected; 346 347 pjdlog_debug_set(debuglevel); 348 pjdlog_prefix_set("[TLS sandbox] (client) "); 349 #ifdef HAVE_SETPROCTITLE 350 setproctitle("[TLS sandbox] (client) "); 351 #endif 352 proto_set("tcp:port", defport); 353 354 sockfd = startfd; 355 356 /* Change tls:// to tcp://. */ 357 if (srcaddr == NULL) { 358 saddr = NULL; 359 } else { 360 saddr = strdup(srcaddr); 361 if (saddr == NULL) 362 pjdlog_exitx(EX_TEMPFAIL, "Unable to allocate memory."); 363 bcopy("tcp://", saddr, 6); 364 } 365 daddr = strdup(dstaddr); 366 if (daddr == NULL) 367 pjdlog_exitx(EX_TEMPFAIL, "Unable to allocate memory."); 368 bcopy("tcp://", daddr, 6); 369 370 /* Establish TCP connection. */ 371 if (proto_connect(saddr, daddr, timeout, &tcp) == -1) 372 exit(EX_TEMPFAIL); 373 374 SSL_load_error_strings(); 375 SSL_library_init(); 376 377 /* 378 * TODO: On FreeBSD we could move this below sandbox() once libc and 379 * libcrypto use sysctl kern.arandom to obtain random data 380 * instead of /dev/urandom and friends. 381 */ 382 sslctx = SSL_CTX_new(TLS_client_method()); 383 if (sslctx == NULL) 384 pjdlog_exitx(EX_TEMPFAIL, "SSL_CTX_new() failed."); 385 386 if (sandbox(user, true, "proto_tls client: %s", dstaddr) != 0) 387 pjdlog_exitx(EX_CONFIG, "Unable to sandbox TLS client."); 388 pjdlog_debug(1, "Privileges successfully dropped."); 389 390 SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); 391 392 /* Load CA certs. */ 393 /* TODO */ 394 //SSL_CTX_load_verify_locations(sslctx, cacerts_file, NULL); 395 396 ssl = SSL_new(sslctx); 397 if (ssl == NULL) 398 pjdlog_exitx(EX_TEMPFAIL, "SSL_new() failed."); 399 400 tcpfd = proto_descriptor(tcp); 401 402 block(tcpfd); 403 404 if (SSL_set_fd(ssl, tcpfd) != 1) 405 pjdlog_exitx(EX_TEMPFAIL, "SSL_set_fd() failed."); 406 407 ret = SSL_connect(ssl); 408 ssl_check_error(ssl, (int)ret); 409 410 nonblock(sockfd); 411 nonblock(tcpfd); 412 413 tls_certificate_verify(ssl, fingerprint); 414 415 /* 416 * The following byte is sent to make proto_connect_wait() work. 417 */ 418 connected = 1; 419 for (;;) { 420 switch (send(sockfd, &connected, sizeof(connected), 0)) { 421 case -1: 422 if (errno == EINTR || errno == ENOBUFS) 423 continue; 424 if (errno == EAGAIN) { 425 (void)wait_for_fd(sockfd, -1); 426 continue; 427 } 428 pjdlog_exit(EX_TEMPFAIL, "send() failed"); 429 case 0: 430 pjdlog_debug(1, "Connection terminated."); 431 exit(0); 432 case 1: 433 break; 434 } 435 break; 436 } 437 438 tls_loop(sockfd, ssl); 439 } 440 441 static void 442 tls_call_exec_client(struct proto_conn *sock, const char *srcaddr, 443 const char *dstaddr, int timeout) 444 { 445 char *timeoutstr, *startfdstr, *debugstr; 446 int startfd; 447 448 /* Declare that we are receiver. */ 449 proto_recv(sock, NULL, 0); 450 451 if (pjdlog_mode_get() == PJDLOG_MODE_STD) 452 startfd = 3; 453 else /* if (pjdlog_mode_get() == PJDLOG_MODE_SYSLOG) */ 454 startfd = 0; 455 456 if (proto_descriptor(sock) != startfd) { 457 /* Move socketpair descriptor to descriptor number startfd. */ 458 if (dup2(proto_descriptor(sock), startfd) == -1) 459 pjdlog_exit(EX_OSERR, "dup2() failed"); 460 proto_close(sock); 461 } else { 462 /* 463 * The FD_CLOEXEC is cleared by dup2(2), so when we do not 464 * call it, we have to clear it by hand in case it is set. 465 */ 466 if (fcntl(startfd, F_SETFD, 0) == -1) 467 pjdlog_exit(EX_OSERR, "fcntl() failed"); 468 } 469 470 closefrom(startfd + 1); 471 472 if (asprintf(&startfdstr, "%d", startfd) == -1) 473 pjdlog_exit(EX_TEMPFAIL, "asprintf() failed"); 474 if (timeout == -1) 475 timeout = TLS_DEFAULT_TIMEOUT; 476 if (asprintf(&timeoutstr, "%d", timeout) == -1) 477 pjdlog_exit(EX_TEMPFAIL, "asprintf() failed"); 478 if (asprintf(&debugstr, "%d", pjdlog_debug_get()) == -1) 479 pjdlog_exit(EX_TEMPFAIL, "asprintf() failed"); 480 481 execl(proto_get("execpath"), proto_get("execpath"), "proto", "tls", 482 proto_get("user"), "client", startfdstr, 483 srcaddr == NULL ? "" : srcaddr, dstaddr, 484 proto_get("tls:fingerprint"), proto_get("tcp:port"), timeoutstr, 485 debugstr, NULL); 486 pjdlog_exit(EX_SOFTWARE, "execl() failed"); 487 } 488 489 static int 490 tls_connect(const char *srcaddr, const char *dstaddr, int timeout, void **ctxp) 491 { 492 struct tls_ctx *tlsctx; 493 struct proto_conn *sock; 494 pid_t pid; 495 int error; 496 497 PJDLOG_ASSERT(srcaddr == NULL || srcaddr[0] != '\0'); 498 PJDLOG_ASSERT(dstaddr != NULL); 499 PJDLOG_ASSERT(timeout >= -1); 500 PJDLOG_ASSERT(ctxp != NULL); 501 502 if (strncmp(dstaddr, "tls://", 6) != 0) 503 return (-1); 504 if (srcaddr != NULL && strncmp(srcaddr, "tls://", 6) != 0) 505 return (-1); 506 507 if (proto_connect(NULL, "socketpair://", -1, &sock) == -1) 508 return (errno); 509 510 #if 0 511 /* 512 * We use rfork() with the following flags to disable SIGCHLD 513 * delivery upon the sandbox process exit. 514 */ 515 pid = rfork(RFFDG | RFPROC | RFTSIGZMB | RFTSIGFLAGS(0)); 516 #else 517 /* 518 * We don't use rfork() to be able to log information about sandbox 519 * process exiting. 520 */ 521 pid = fork(); 522 #endif 523 switch (pid) { 524 case -1: 525 /* Failure. */ 526 error = errno; 527 proto_close(sock); 528 return (error); 529 case 0: 530 /* Child. */ 531 pjdlog_prefix_set("[TLS sandbox] (client) "); 532 #ifdef HAVE_SETPROCTITLE 533 setproctitle("[TLS sandbox] (client) "); 534 #endif 535 tls_call_exec_client(sock, srcaddr, dstaddr, timeout); 536 /* NOTREACHED */ 537 default: 538 /* Parent. */ 539 tlsctx = calloc(1, sizeof(*tlsctx)); 540 if (tlsctx == NULL) { 541 error = errno; 542 proto_close(sock); 543 (void)kill(pid, SIGKILL); 544 return (error); 545 } 546 proto_send(sock, NULL, 0); 547 tlsctx->tls_sock = sock; 548 tlsctx->tls_tcp = NULL; 549 tlsctx->tls_side = TLS_SIDE_CLIENT; 550 tlsctx->tls_wait_called = false; 551 tlsctx->tls_magic = TLS_CTX_MAGIC; 552 if (timeout >= 0) { 553 error = tls_connect_wait(tlsctx, timeout); 554 if (error != 0) { 555 (void)kill(pid, SIGKILL); 556 tls_close(tlsctx); 557 return (error); 558 } 559 } 560 *ctxp = tlsctx; 561 return (0); 562 } 563 } 564 565 static int 566 tls_connect_wait(void *ctx, int timeout) 567 { 568 struct tls_ctx *tlsctx = ctx; 569 int error, sockfd; 570 uint8_t connected; 571 572 PJDLOG_ASSERT(tlsctx != NULL); 573 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 574 PJDLOG_ASSERT(tlsctx->tls_side == TLS_SIDE_CLIENT); 575 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 576 PJDLOG_ASSERT(!tlsctx->tls_wait_called); 577 PJDLOG_ASSERT(timeout >= 0); 578 579 sockfd = proto_descriptor(tlsctx->tls_sock); 580 error = wait_for_fd(sockfd, timeout); 581 if (error != 0) 582 return (error); 583 584 for (;;) { 585 switch (recv(sockfd, &connected, sizeof(connected), 586 MSG_WAITALL)) { 587 case -1: 588 if (errno == EINTR || errno == ENOBUFS) 589 continue; 590 error = errno; 591 break; 592 case 0: 593 pjdlog_debug(1, "Connection terminated."); 594 error = ENOTCONN; 595 break; 596 case 1: 597 tlsctx->tls_wait_called = true; 598 break; 599 } 600 break; 601 } 602 603 return (error); 604 } 605 606 static int 607 tls_server(const char *lstaddr, void **ctxp) 608 { 609 struct proto_conn *tcp; 610 struct tls_ctx *tlsctx; 611 char *laddr; 612 int error; 613 614 if (strncmp(lstaddr, "tls://", 6) != 0) 615 return (-1); 616 617 tlsctx = malloc(sizeof(*tlsctx)); 618 if (tlsctx == NULL) { 619 pjdlog_warning("Unable to allocate memory."); 620 return (ENOMEM); 621 } 622 623 laddr = strdup(lstaddr); 624 if (laddr == NULL) { 625 free(tlsctx); 626 pjdlog_warning("Unable to allocate memory."); 627 return (ENOMEM); 628 } 629 bcopy("tcp://", laddr, 6); 630 631 if (proto_server(laddr, &tcp) == -1) { 632 error = errno; 633 free(tlsctx); 634 free(laddr); 635 return (error); 636 } 637 free(laddr); 638 639 tlsctx->tls_sock = NULL; 640 tlsctx->tls_tcp = tcp; 641 tlsctx->tls_side = TLS_SIDE_SERVER_LISTEN; 642 tlsctx->tls_wait_called = true; 643 tlsctx->tls_magic = TLS_CTX_MAGIC; 644 *ctxp = tlsctx; 645 646 return (0); 647 } 648 649 static void 650 tls_exec_server(const char *user, int startfd, const char *privkey, 651 const char *cert, int debuglevel) 652 { 653 SSL_CTX *sslctx; 654 SSL *ssl; 655 int sockfd, tcpfd, ret; 656 657 pjdlog_debug_set(debuglevel); 658 pjdlog_prefix_set("[TLS sandbox] (server) "); 659 #ifdef HAVE_SETPROCTITLE 660 setproctitle("[TLS sandbox] (server) "); 661 #endif 662 663 sockfd = startfd; 664 tcpfd = startfd + 1; 665 666 SSL_load_error_strings(); 667 SSL_library_init(); 668 669 sslctx = SSL_CTX_new(TLS_server_method()); 670 if (sslctx == NULL) 671 pjdlog_exitx(EX_TEMPFAIL, "SSL_CTX_new() failed."); 672 673 SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); 674 675 ssl = SSL_new(sslctx); 676 if (ssl == NULL) 677 pjdlog_exitx(EX_TEMPFAIL, "SSL_new() failed."); 678 679 if (SSL_use_RSAPrivateKey_file(ssl, privkey, SSL_FILETYPE_PEM) != 1) { 680 ssl_log_errors(); 681 pjdlog_exitx(EX_CONFIG, 682 "SSL_use_RSAPrivateKey_file(%s) failed.", privkey); 683 } 684 685 if (SSL_use_certificate_file(ssl, cert, SSL_FILETYPE_PEM) != 1) { 686 ssl_log_errors(); 687 pjdlog_exitx(EX_CONFIG, "SSL_use_certificate_file(%s) failed.", 688 cert); 689 } 690 691 if (sandbox(user, true, "proto_tls server") != 0) 692 pjdlog_exitx(EX_CONFIG, "Unable to sandbox TLS server."); 693 pjdlog_debug(1, "Privileges successfully dropped."); 694 695 nonblock(sockfd); 696 nonblock(tcpfd); 697 698 if (SSL_set_fd(ssl, tcpfd) != 1) 699 pjdlog_exitx(EX_TEMPFAIL, "SSL_set_fd() failed."); 700 701 ret = SSL_accept(ssl); 702 ssl_check_error(ssl, ret); 703 704 tls_loop(sockfd, ssl); 705 } 706 707 static void 708 tls_call_exec_server(struct proto_conn *sock, struct proto_conn *tcp) 709 { 710 int startfd, sockfd, tcpfd, safefd; 711 char *startfdstr, *debugstr; 712 713 if (pjdlog_mode_get() == PJDLOG_MODE_STD) 714 startfd = 3; 715 else /* if (pjdlog_mode_get() == PJDLOG_MODE_SYSLOG) */ 716 startfd = 0; 717 718 /* Declare that we are receiver. */ 719 proto_send(sock, NULL, 0); 720 721 sockfd = proto_descriptor(sock); 722 tcpfd = proto_descriptor(tcp); 723 724 safefd = MAX(sockfd, tcpfd); 725 safefd = MAX(safefd, startfd); 726 safefd++; 727 728 /* Move sockfd and tcpfd to safe numbers first. */ 729 if (dup2(sockfd, safefd) == -1) 730 pjdlog_exit(EX_OSERR, "dup2() failed"); 731 proto_close(sock); 732 sockfd = safefd; 733 if (dup2(tcpfd, safefd + 1) == -1) 734 pjdlog_exit(EX_OSERR, "dup2() failed"); 735 proto_close(tcp); 736 tcpfd = safefd + 1; 737 738 /* Move socketpair descriptor to descriptor number startfd. */ 739 if (dup2(sockfd, startfd) == -1) 740 pjdlog_exit(EX_OSERR, "dup2() failed"); 741 (void)close(sockfd); 742 /* Move tcp descriptor to descriptor number startfd + 1. */ 743 if (dup2(tcpfd, startfd + 1) == -1) 744 pjdlog_exit(EX_OSERR, "dup2() failed"); 745 (void)close(tcpfd); 746 747 closefrom(startfd + 2); 748 749 /* 750 * Even if FD_CLOEXEC was set on descriptors before dup2(), it should 751 * have been cleared on dup2(), but better be safe than sorry. 752 */ 753 if (fcntl(startfd, F_SETFD, 0) == -1) 754 pjdlog_exit(EX_OSERR, "fcntl() failed"); 755 if (fcntl(startfd + 1, F_SETFD, 0) == -1) 756 pjdlog_exit(EX_OSERR, "fcntl() failed"); 757 758 if (asprintf(&startfdstr, "%d", startfd) == -1) 759 pjdlog_exit(EX_TEMPFAIL, "asprintf() failed"); 760 if (asprintf(&debugstr, "%d", pjdlog_debug_get()) == -1) 761 pjdlog_exit(EX_TEMPFAIL, "asprintf() failed"); 762 763 execl(proto_get("execpath"), proto_get("execpath"), "proto", "tls", 764 proto_get("user"), "server", startfdstr, proto_get("tls:keyfile"), 765 proto_get("tls:certfile"), debugstr, NULL); 766 pjdlog_exit(EX_SOFTWARE, "execl() failed"); 767 } 768 769 static int 770 tls_accept(void *ctx, void **newctxp) 771 { 772 struct tls_ctx *tlsctx = ctx; 773 struct tls_ctx *newtlsctx; 774 struct proto_conn *sock, *tcp; 775 pid_t pid; 776 int error; 777 778 PJDLOG_ASSERT(tlsctx != NULL); 779 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 780 PJDLOG_ASSERT(tlsctx->tls_side == TLS_SIDE_SERVER_LISTEN); 781 782 if (proto_connect(NULL, "socketpair://", -1, &sock) == -1) 783 return (errno); 784 785 /* Accept TCP connection. */ 786 if (proto_accept(tlsctx->tls_tcp, &tcp) == -1) { 787 error = errno; 788 proto_close(sock); 789 return (error); 790 } 791 792 pid = fork(); 793 switch (pid) { 794 case -1: 795 /* Failure. */ 796 error = errno; 797 proto_close(sock); 798 return (error); 799 case 0: 800 /* Child. */ 801 pjdlog_prefix_set("[TLS sandbox] (server) "); 802 #ifdef HAVE_SETPROCTITLE 803 setproctitle("[TLS sandbox] (server) "); 804 #endif 805 /* Close listen socket. */ 806 proto_close(tlsctx->tls_tcp); 807 tls_call_exec_server(sock, tcp); 808 /* NOTREACHED */ 809 PJDLOG_ABORT("Unreachable."); 810 default: 811 /* Parent. */ 812 newtlsctx = calloc(1, sizeof(*tlsctx)); 813 if (newtlsctx == NULL) { 814 error = errno; 815 proto_close(sock); 816 proto_close(tcp); 817 (void)kill(pid, SIGKILL); 818 return (error); 819 } 820 proto_local_address(tcp, newtlsctx->tls_laddr, 821 sizeof(newtlsctx->tls_laddr)); 822 PJDLOG_ASSERT(strncmp(newtlsctx->tls_laddr, "tcp://", 6) == 0); 823 bcopy("tls://", newtlsctx->tls_laddr, 6); 824 *strrchr(newtlsctx->tls_laddr, ':') = '\0'; 825 proto_remote_address(tcp, newtlsctx->tls_raddr, 826 sizeof(newtlsctx->tls_raddr)); 827 PJDLOG_ASSERT(strncmp(newtlsctx->tls_raddr, "tcp://", 6) == 0); 828 bcopy("tls://", newtlsctx->tls_raddr, 6); 829 *strrchr(newtlsctx->tls_raddr, ':') = '\0'; 830 proto_close(tcp); 831 proto_recv(sock, NULL, 0); 832 newtlsctx->tls_sock = sock; 833 newtlsctx->tls_tcp = NULL; 834 newtlsctx->tls_wait_called = true; 835 newtlsctx->tls_side = TLS_SIDE_SERVER_WORK; 836 newtlsctx->tls_magic = TLS_CTX_MAGIC; 837 *newctxp = newtlsctx; 838 return (0); 839 } 840 } 841 842 static int 843 tls_wrap(int fd, bool client, void **ctxp) 844 { 845 struct tls_ctx *tlsctx; 846 struct proto_conn *sock; 847 int error; 848 849 tlsctx = calloc(1, sizeof(*tlsctx)); 850 if (tlsctx == NULL) 851 return (errno); 852 853 if (proto_wrap("socketpair", client, fd, &sock) == -1) { 854 error = errno; 855 free(tlsctx); 856 return (error); 857 } 858 859 tlsctx->tls_sock = sock; 860 tlsctx->tls_tcp = NULL; 861 tlsctx->tls_wait_called = (client ? false : true); 862 tlsctx->tls_side = (client ? TLS_SIDE_CLIENT : TLS_SIDE_SERVER_WORK); 863 tlsctx->tls_magic = TLS_CTX_MAGIC; 864 *ctxp = tlsctx; 865 866 return (0); 867 } 868 869 static int 870 tls_send(void *ctx, const unsigned char *data, size_t size, int fd) 871 { 872 struct tls_ctx *tlsctx = ctx; 873 874 PJDLOG_ASSERT(tlsctx != NULL); 875 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 876 PJDLOG_ASSERT(tlsctx->tls_side == TLS_SIDE_CLIENT || 877 tlsctx->tls_side == TLS_SIDE_SERVER_WORK); 878 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 879 PJDLOG_ASSERT(tlsctx->tls_wait_called); 880 PJDLOG_ASSERT(fd == -1); 881 882 if (proto_send(tlsctx->tls_sock, data, size) == -1) 883 return (errno); 884 885 return (0); 886 } 887 888 static int 889 tls_recv(void *ctx, unsigned char *data, size_t size, int *fdp) 890 { 891 struct tls_ctx *tlsctx = ctx; 892 893 PJDLOG_ASSERT(tlsctx != NULL); 894 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 895 PJDLOG_ASSERT(tlsctx->tls_side == TLS_SIDE_CLIENT || 896 tlsctx->tls_side == TLS_SIDE_SERVER_WORK); 897 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 898 PJDLOG_ASSERT(tlsctx->tls_wait_called); 899 PJDLOG_ASSERT(fdp == NULL); 900 901 if (proto_recv(tlsctx->tls_sock, data, size) == -1) 902 return (errno); 903 904 return (0); 905 } 906 907 static int 908 tls_descriptor(const void *ctx) 909 { 910 const struct tls_ctx *tlsctx = ctx; 911 912 PJDLOG_ASSERT(tlsctx != NULL); 913 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 914 915 switch (tlsctx->tls_side) { 916 case TLS_SIDE_CLIENT: 917 case TLS_SIDE_SERVER_WORK: 918 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 919 920 return (proto_descriptor(tlsctx->tls_sock)); 921 case TLS_SIDE_SERVER_LISTEN: 922 PJDLOG_ASSERT(tlsctx->tls_tcp != NULL); 923 924 return (proto_descriptor(tlsctx->tls_tcp)); 925 default: 926 PJDLOG_ABORT("Invalid side (%d).", tlsctx->tls_side); 927 } 928 } 929 930 static bool 931 tcp_address_match(const void *ctx, const char *addr) 932 { 933 const struct tls_ctx *tlsctx = ctx; 934 935 PJDLOG_ASSERT(tlsctx != NULL); 936 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 937 938 return (strcmp(tlsctx->tls_raddr, addr) == 0); 939 } 940 941 static void 942 tls_local_address(const void *ctx, char *addr, size_t size) 943 { 944 const struct tls_ctx *tlsctx = ctx; 945 946 PJDLOG_ASSERT(tlsctx != NULL); 947 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 948 PJDLOG_ASSERT(tlsctx->tls_wait_called); 949 950 switch (tlsctx->tls_side) { 951 case TLS_SIDE_CLIENT: 952 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 953 954 PJDLOG_VERIFY(strlcpy(addr, "tls://N/A", size) < size); 955 break; 956 case TLS_SIDE_SERVER_WORK: 957 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 958 959 PJDLOG_VERIFY(strlcpy(addr, tlsctx->tls_laddr, size) < size); 960 break; 961 case TLS_SIDE_SERVER_LISTEN: 962 PJDLOG_ASSERT(tlsctx->tls_tcp != NULL); 963 964 proto_local_address(tlsctx->tls_tcp, addr, size); 965 PJDLOG_ASSERT(strncmp(addr, "tcp://", 6) == 0); 966 /* Replace tcp:// prefix with tls:// */ 967 bcopy("tls://", addr, 6); 968 break; 969 default: 970 PJDLOG_ABORT("Invalid side (%d).", tlsctx->tls_side); 971 } 972 } 973 974 static void 975 tls_remote_address(const void *ctx, char *addr, size_t size) 976 { 977 const struct tls_ctx *tlsctx = ctx; 978 979 PJDLOG_ASSERT(tlsctx != NULL); 980 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 981 PJDLOG_ASSERT(tlsctx->tls_wait_called); 982 983 switch (tlsctx->tls_side) { 984 case TLS_SIDE_CLIENT: 985 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 986 987 PJDLOG_VERIFY(strlcpy(addr, "tls://N/A", size) < size); 988 break; 989 case TLS_SIDE_SERVER_WORK: 990 PJDLOG_ASSERT(tlsctx->tls_sock != NULL); 991 992 PJDLOG_VERIFY(strlcpy(addr, tlsctx->tls_raddr, size) < size); 993 break; 994 case TLS_SIDE_SERVER_LISTEN: 995 PJDLOG_ASSERT(tlsctx->tls_tcp != NULL); 996 997 proto_remote_address(tlsctx->tls_tcp, addr, size); 998 PJDLOG_ASSERT(strncmp(addr, "tcp://", 6) == 0); 999 /* Replace tcp:// prefix with tls:// */ 1000 bcopy("tls://", addr, 6); 1001 break; 1002 default: 1003 PJDLOG_ABORT("Invalid side (%d).", tlsctx->tls_side); 1004 } 1005 } 1006 1007 static void 1008 tls_close(void *ctx) 1009 { 1010 struct tls_ctx *tlsctx = ctx; 1011 1012 PJDLOG_ASSERT(tlsctx != NULL); 1013 PJDLOG_ASSERT(tlsctx->tls_magic == TLS_CTX_MAGIC); 1014 1015 if (tlsctx->tls_sock != NULL) { 1016 proto_close(tlsctx->tls_sock); 1017 tlsctx->tls_sock = NULL; 1018 } 1019 if (tlsctx->tls_tcp != NULL) { 1020 proto_close(tlsctx->tls_tcp); 1021 tlsctx->tls_tcp = NULL; 1022 } 1023 tlsctx->tls_side = 0; 1024 tlsctx->tls_magic = 0; 1025 free(tlsctx); 1026 } 1027 1028 static int 1029 tls_exec(int argc, char *argv[]) 1030 { 1031 1032 PJDLOG_ASSERT(argc > 3); 1033 PJDLOG_ASSERT(strcmp(argv[0], "tls") == 0); 1034 1035 pjdlog_init(atoi(argv[3]) == 0 ? PJDLOG_MODE_SYSLOG : PJDLOG_MODE_STD); 1036 1037 if (strcmp(argv[2], "client") == 0) { 1038 if (argc != 10) 1039 return (EINVAL); 1040 tls_exec_client(argv[1], atoi(argv[3]), 1041 argv[4][0] == '\0' ? NULL : argv[4], argv[5], argv[6], 1042 argv[7], atoi(argv[8]), atoi(argv[9])); 1043 } else if (strcmp(argv[2], "server") == 0) { 1044 if (argc != 7) 1045 return (EINVAL); 1046 tls_exec_server(argv[1], atoi(argv[3]), argv[4], argv[5], 1047 atoi(argv[6])); 1048 } 1049 return (EINVAL); 1050 } 1051 1052 static struct proto tls_proto = { 1053 .prt_name = "tls", 1054 .prt_connect = tls_connect, 1055 .prt_connect_wait = tls_connect_wait, 1056 .prt_server = tls_server, 1057 .prt_accept = tls_accept, 1058 .prt_wrap = tls_wrap, 1059 .prt_send = tls_send, 1060 .prt_recv = tls_recv, 1061 .prt_descriptor = tls_descriptor, 1062 .prt_address_match = tcp_address_match, 1063 .prt_local_address = tls_local_address, 1064 .prt_remote_address = tls_remote_address, 1065 .prt_close = tls_close, 1066 .prt_exec = tls_exec 1067 }; 1068 1069 static __constructor void 1070 tls_ctor(void) 1071 { 1072 1073 proto_register(&tls_proto, false); 1074 } 1075