1 /* $NetBSD: ssl.c,v 1.8 2019/04/07 00:44:54 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1998-2004 Dag-Erling Coïdan Smørgrav 5 * Copyright (c) 2008, 2010 Joerg Sonnenberger <joerg@NetBSD.org> 6 * Copyright (c) 2015 Thomas Klausner <wiz@NetBSD.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer 14 * in this position and unchanged. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 * $FreeBSD: common.c,v 1.53 2007/12/19 00:26:36 des Exp $ 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 __RCSID("$NetBSD: ssl.c,v 1.8 2019/04/07 00:44:54 christos Exp $"); 38 #endif 39 40 #include <time.h> 41 #include <unistd.h> 42 #include <string.h> 43 #include <fcntl.h> 44 45 #include <sys/param.h> 46 #include <sys/select.h> 47 #include <sys/uio.h> 48 49 #include <netinet/tcp.h> 50 #include <netinet/in.h> 51 #include <openssl/crypto.h> 52 #include <openssl/x509.h> 53 #include <openssl/pem.h> 54 #include <openssl/ssl.h> 55 #include <openssl/err.h> 56 57 #include "ssl.h" 58 59 extern int quit_time, verbose, ftp_debug; 60 extern FILE *ttyout; 61 62 struct fetch_connect { 63 int sd; /* file/socket descriptor */ 64 char *buf; /* buffer */ 65 size_t bufsize; /* buffer size */ 66 size_t bufpos; /* position of buffer */ 67 size_t buflen; /* length of buffer contents */ 68 struct { /* data cached after an 69 interrupted read */ 70 char *buf; 71 size_t size; 72 size_t pos; 73 size_t len; 74 } cache; 75 int issock; 76 int iserr; 77 int iseof; 78 SSL *ssl; /* SSL handle */ 79 }; 80 81 /* 82 * Write a vector to a connection w/ timeout 83 * Note: can modify the iovec. 84 */ 85 static ssize_t 86 fetch_writev(struct fetch_connect *conn, struct iovec *iov, int iovcnt) 87 { 88 struct timeval now, timeout, delta; 89 fd_set writefds; 90 ssize_t len, total; 91 int fd = conn->sd; 92 int r; 93 94 if (quit_time > 0) { 95 FD_ZERO(&writefds); 96 gettimeofday(&timeout, NULL); 97 timeout.tv_sec += quit_time; 98 } 99 100 total = 0; 101 while (iovcnt > 0) { 102 while (quit_time > 0 && !FD_ISSET(fd, &writefds)) { 103 FD_SET(fd, &writefds); 104 gettimeofday(&now, NULL); 105 delta.tv_sec = timeout.tv_sec - now.tv_sec; 106 delta.tv_usec = timeout.tv_usec - now.tv_usec; 107 if (delta.tv_usec < 0) { 108 delta.tv_usec += 1000000; 109 delta.tv_sec--; 110 } 111 if (delta.tv_sec < 0) { 112 errno = ETIMEDOUT; 113 return -1; 114 } 115 errno = 0; 116 r = select(fd + 1, NULL, &writefds, NULL, &delta); 117 if (r == -1) { 118 if (errno == EINTR) 119 continue; 120 return -1; 121 } 122 } 123 errno = 0; 124 if (conn->ssl != NULL) 125 len = SSL_write(conn->ssl, iov->iov_base, iov->iov_len); 126 else 127 len = writev(fd, iov, iovcnt); 128 if (len == 0) { 129 /* we consider a short write a failure */ 130 /* XXX perhaps we shouldn't in the SSL case */ 131 errno = EPIPE; 132 return -1; 133 } 134 if (len < 0) { 135 if (errno == EINTR || errno == EAGAIN) 136 continue; 137 return -1; 138 } 139 total += len; 140 while (iovcnt > 0 && len >= (ssize_t)iov->iov_len) { 141 len -= iov->iov_len; 142 iov++; 143 iovcnt--; 144 } 145 if (iovcnt > 0) { 146 iov->iov_len -= len; 147 iov->iov_base = (char *)iov->iov_base + len; 148 } 149 } 150 return total; 151 } 152 153 static ssize_t 154 fetch_write(const void *str, size_t len, struct fetch_connect *conn) 155 { 156 struct iovec iov[1]; 157 158 iov[0].iov_base = (char *)__UNCONST(str); 159 iov[0].iov_len = len; 160 return fetch_writev(conn, iov, 1); 161 } 162 163 /* 164 * Send a formatted line; optionally echo to terminal 165 */ 166 int 167 fetch_printf(struct fetch_connect *conn, const char *fmt, ...) 168 { 169 va_list ap; 170 size_t len; 171 char *msg; 172 int r; 173 174 va_start(ap, fmt); 175 len = vasprintf(&msg, fmt, ap); 176 va_end(ap); 177 178 if (msg == NULL) { 179 errno = ENOMEM; 180 return -1; 181 } 182 183 r = fetch_write(msg, len, conn); 184 free(msg); 185 return r; 186 } 187 188 int 189 fetch_fileno(struct fetch_connect *conn) 190 { 191 192 return conn->sd; 193 } 194 195 int 196 fetch_error(struct fetch_connect *conn) 197 { 198 199 return conn->iserr; 200 } 201 202 static void 203 fetch_clearerr(struct fetch_connect *conn) 204 { 205 206 conn->iserr = 0; 207 } 208 209 int 210 fetch_flush(struct fetch_connect *conn) 211 { 212 213 if (conn->issock) { 214 int fd = conn->sd; 215 int v; 216 #ifdef TCP_NOPUSH 217 v = 0; 218 setsockopt(fd, IPPROTO_TCP, TCP_NOPUSH, &v, sizeof(v)); 219 #endif 220 v = 1; 221 setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v)); 222 } 223 return 0; 224 } 225 226 /*ARGSUSED*/ 227 struct fetch_connect * 228 fetch_open(const char *fname, const char *fmode) 229 { 230 struct fetch_connect *conn; 231 int fd; 232 233 fd = open(fname, O_RDONLY); /* XXX: fmode */ 234 if (fd < 0) 235 return NULL; 236 237 if ((conn = calloc(1, sizeof(*conn))) == NULL) { 238 close(fd); 239 return NULL; 240 } 241 242 conn->sd = fd; 243 conn->issock = 0; 244 return conn; 245 } 246 247 /*ARGSUSED*/ 248 struct fetch_connect * 249 fetch_fdopen(int sd, const char *fmode) 250 { 251 struct fetch_connect *conn; 252 #if defined(SO_NOSIGPIPE) || defined(TCP_NOPUSH) 253 int opt = 1; 254 #endif 255 256 if ((conn = calloc(1, sizeof(*conn))) == NULL) 257 return NULL; 258 259 conn->sd = sd; 260 conn->issock = 1; 261 fcntl(sd, F_SETFD, FD_CLOEXEC); 262 #ifdef SO_NOSIGPIPE 263 setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt)); 264 #endif 265 #ifdef TCP_NOPUSH 266 setsockopt(sd, IPPROTO_TCP, TCP_NOPUSH, &opt, sizeof(opt)); 267 #endif 268 return conn; 269 } 270 271 int 272 fetch_close(struct fetch_connect *conn) 273 { 274 if (conn == NULL) 275 return 0; 276 277 fetch_flush(conn); 278 SSL_free(conn->ssl); 279 close(conn->sd); 280 free(conn->cache.buf); 281 free(conn->buf); 282 free(conn); 283 return 0; 284 } 285 286 #define FETCH_WRITE_WAIT -3 287 #define FETCH_READ_WAIT -2 288 #define FETCH_READ_ERROR -1 289 290 static ssize_t 291 fetch_ssl_read(SSL *ssl, void *buf, size_t len) 292 { 293 ssize_t rlen; 294 rlen = SSL_read(ssl, buf, len); 295 if (rlen >= 0) 296 return rlen; 297 298 switch (SSL_get_error(ssl, rlen)) { 299 case SSL_ERROR_WANT_READ: 300 return FETCH_READ_WAIT; 301 case SSL_ERROR_WANT_WRITE: 302 return FETCH_WRITE_WAIT; 303 default: 304 ERR_print_errors_fp(ttyout); 305 return FETCH_READ_ERROR; 306 } 307 } 308 309 static ssize_t 310 fetch_nonssl_read(int sd, void *buf, size_t len) 311 { 312 ssize_t rlen; 313 314 rlen = read(sd, buf, len); 315 if (rlen == -1) { 316 if (errno == EAGAIN || errno == EINTR) 317 return FETCH_READ_WAIT; 318 return FETCH_READ_ERROR; 319 } 320 return rlen; 321 } 322 323 /* 324 * Cache some data that was read from a socket but cannot be immediately 325 * returned because of an interrupted system call. 326 */ 327 static int 328 fetch_cache_data(struct fetch_connect *conn, char *src, size_t nbytes) 329 { 330 331 if (conn->cache.size < nbytes) { 332 char *tmp = realloc(conn->cache.buf, nbytes); 333 if (tmp == NULL) 334 return -1; 335 336 conn->cache.buf = tmp; 337 conn->cache.size = nbytes; 338 } 339 340 memcpy(conn->cache.buf, src, nbytes); 341 conn->cache.len = nbytes; 342 conn->cache.pos = 0; 343 return 0; 344 } 345 346 static int 347 fetch_wait(struct fetch_connect *conn, ssize_t rlen, struct timeval *timeout) 348 { 349 struct timeval now, delta; 350 int fd = conn->sd; 351 fd_set fds; 352 353 FD_ZERO(&fds); 354 while (!FD_ISSET(fd, &fds)) { 355 FD_SET(fd, &fds); 356 if (quit_time > 0) { 357 gettimeofday(&now, NULL); 358 if (!timercmp(timeout, &now, >)) { 359 conn->iserr = ETIMEDOUT; 360 return -1; 361 } 362 timersub(timeout, &now, &delta); 363 } 364 errno = 0; 365 if (select(fd + 1, 366 rlen == FETCH_READ_WAIT ? &fds : NULL, 367 rlen == FETCH_WRITE_WAIT ? &fds : NULL, 368 NULL, quit_time > 0 ? &delta : NULL) < 0) { 369 if (errno == EINTR) 370 continue; 371 conn->iserr = errno; 372 return -1; 373 } 374 } 375 return 0; 376 } 377 378 size_t 379 fetch_read(void *ptr, size_t size, size_t nmemb, struct fetch_connect *conn) 380 { 381 ssize_t rlen, total; 382 size_t len; 383 char *start, *buf; 384 struct timeval timeout; 385 386 if (quit_time > 0) { 387 gettimeofday(&timeout, NULL); 388 timeout.tv_sec += quit_time; 389 } 390 391 total = 0; 392 start = buf = ptr; 393 len = size * nmemb; 394 395 if (conn->cache.len > 0) { 396 /* 397 * The last invocation of fetch_read was interrupted by a 398 * signal after some data had been read from the socket. Copy 399 * the cached data into the supplied buffer before trying to 400 * read from the socket again. 401 */ 402 total = (conn->cache.len < len) ? conn->cache.len : len; 403 memcpy(buf, conn->cache.buf, total); 404 405 conn->cache.len -= total; 406 conn->cache.pos += total; 407 len -= total; 408 buf += total; 409 } 410 411 while (len > 0) { 412 /* 413 * The socket is non-blocking. Instead of the canonical 414 * select() -> read(), we do the following: 415 * 416 * 1) call read() or SSL_read(). 417 * 2) if an error occurred, return -1. 418 * 3) if we received data but we still expect more, 419 * update our counters and loop. 420 * 4) if read() or SSL_read() signaled EOF, return. 421 * 5) if we did not receive any data but we're not at EOF, 422 * call select(). 423 * 424 * In the SSL case, this is necessary because if we 425 * receive a close notification, we have to call 426 * SSL_read() one additional time after we've read 427 * everything we received. 428 * 429 * In the non-SSL case, it may improve performance (very 430 * slightly) when reading small amounts of data. 431 */ 432 if (conn->ssl != NULL) 433 rlen = fetch_ssl_read(conn->ssl, buf, len); 434 else 435 rlen = fetch_nonssl_read(conn->sd, buf, len); 436 switch (rlen) { 437 case 0: 438 conn->iseof = 1; 439 return total; 440 case FETCH_READ_ERROR: 441 conn->iserr = errno; 442 if (errno == EINTR) 443 fetch_cache_data(conn, start, total); 444 return 0; 445 case FETCH_READ_WAIT: 446 case FETCH_WRITE_WAIT: 447 if (fetch_wait(conn, rlen, &timeout) == -1) 448 return 0; 449 break; 450 default: 451 len -= rlen; 452 buf += rlen; 453 total += rlen; 454 break; 455 } 456 } 457 return total; 458 } 459 460 #define MIN_BUF_SIZE 1024 461 462 /* 463 * Read a line of text from a connection w/ timeout 464 */ 465 char * 466 fetch_getln(char *str, int size, struct fetch_connect *conn) 467 { 468 size_t tmpsize; 469 size_t len; 470 char c; 471 472 if (conn->buf == NULL) { 473 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) { 474 errno = ENOMEM; 475 conn->iserr = 1; 476 return NULL; 477 } 478 conn->bufsize = MIN_BUF_SIZE; 479 } 480 481 if (conn->iserr || conn->iseof) 482 return NULL; 483 484 if (conn->buflen - conn->bufpos > 0) 485 goto done; 486 487 conn->buf[0] = '\0'; 488 conn->bufpos = 0; 489 conn->buflen = 0; 490 do { 491 len = fetch_read(&c, sizeof(c), 1, conn); 492 if (len == 0) { 493 if (conn->iserr) 494 return NULL; 495 if (conn->iseof) 496 break; 497 abort(); 498 } 499 conn->buf[conn->buflen++] = c; 500 if (conn->buflen == conn->bufsize) { 501 char *tmp = conn->buf; 502 tmpsize = conn->bufsize * 2 + 1; 503 if ((tmp = realloc(tmp, tmpsize)) == NULL) { 504 errno = ENOMEM; 505 conn->iserr = 1; 506 return NULL; 507 } 508 conn->buf = tmp; 509 conn->bufsize = tmpsize; 510 } 511 } while (c != '\n'); 512 513 if (conn->buflen == 0) 514 return NULL; 515 done: 516 tmpsize = MIN(size - 1, (int)(conn->buflen - conn->bufpos)); 517 memcpy(str, conn->buf + conn->bufpos, tmpsize); 518 str[tmpsize] = '\0'; 519 conn->bufpos += tmpsize; 520 return str; 521 } 522 523 int 524 fetch_getline(struct fetch_connect *conn, char *buf, size_t buflen, 525 const char **errormsg) 526 { 527 size_t len; 528 int rv; 529 530 if (fetch_getln(buf, buflen, conn) == NULL) { 531 if (conn->iseof) { /* EOF */ 532 rv = -2; 533 if (errormsg) 534 *errormsg = "\nEOF received"; 535 } else { /* error */ 536 rv = -1; 537 if (errormsg) 538 *errormsg = "Error encountered"; 539 } 540 fetch_clearerr(conn); 541 return rv; 542 } 543 len = strlen(buf); 544 if (buf[len - 1] == '\n') { /* clear any trailing newline */ 545 buf[--len] = '\0'; 546 } else if (len == buflen - 1) { /* line too long */ 547 while (1) { 548 char c; 549 size_t rlen = fetch_read(&c, sizeof(c), 1, conn); 550 if (rlen == 0 || c == '\n') 551 break; 552 } 553 if (errormsg) 554 *errormsg = "Input line is too long"; 555 fetch_clearerr(conn); 556 return -3; 557 } 558 if (errormsg) 559 *errormsg = NULL; 560 return len; 561 } 562 563 void * 564 fetch_start_ssl(int sock, const char *servername) 565 { 566 SSL *ssl; 567 SSL_CTX *ctx; 568 int ret, ssl_err; 569 570 /* Init the SSL library and context */ 571 if (!SSL_library_init()){ 572 fprintf(ttyout, "SSL library init failed\n"); 573 return NULL; 574 } 575 576 SSL_load_error_strings(); 577 578 ctx = SSL_CTX_new(SSLv23_client_method()); 579 SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY); 580 581 ssl = SSL_new(ctx); 582 if (ssl == NULL){ 583 fprintf(ttyout, "SSL context creation failed\n"); 584 SSL_CTX_free(ctx); 585 return NULL; 586 } 587 SSL_set_fd(ssl, sock); 588 if (!SSL_set_tlsext_host_name(ssl, __UNCONST(servername))) { 589 fprintf(ttyout, "SSL hostname setting failed\n"); 590 SSL_CTX_free(ctx); 591 return NULL; 592 } 593 while ((ret = SSL_connect(ssl)) == -1) { 594 ssl_err = SSL_get_error(ssl, ret); 595 if (ssl_err != SSL_ERROR_WANT_READ && 596 ssl_err != SSL_ERROR_WANT_WRITE) { 597 ERR_print_errors_fp(ttyout); 598 SSL_free(ssl); 599 return NULL; 600 } 601 } 602 603 if (ftp_debug && verbose) { 604 X509 *cert; 605 X509_NAME *name; 606 char *str; 607 608 fprintf(ttyout, "SSL connection established using %s\n", 609 SSL_get_cipher(ssl)); 610 cert = SSL_get_peer_certificate(ssl); 611 name = X509_get_subject_name(cert); 612 str = X509_NAME_oneline(name, 0, 0); 613 fprintf(ttyout, "Certificate subject: %s\n", str); 614 free(str); 615 name = X509_get_issuer_name(cert); 616 str = X509_NAME_oneline(name, 0, 0); 617 fprintf(ttyout, "Certificate issuer: %s\n", str); 618 free(str); 619 } 620 621 return ssl; 622 } 623 624 625 void 626 fetch_set_ssl(struct fetch_connect *conn, void *ssl) 627 { 628 conn->ssl = ssl; 629 } 630