1 /* $OpenBSD: ssh-keyscan.c,v 1.153 2023/06/21 05:06:04 djm Exp $ */ 2 /* 3 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>. 4 * 5 * Modification and redistribution in source and binary forms is 6 * permitted provided that due credit is given to the author and the 7 * OpenBSD project by leaving this copyright notice intact. 8 */ 9 10 #include "includes.h" 11 12 #include <sys/types.h> 13 #include "openbsd-compat/sys-queue.h" 14 #include <sys/resource.h> 15 #ifdef HAVE_SYS_TIME_H 16 # include <sys/time.h> 17 #endif 18 19 #include <netinet/in.h> 20 #include <arpa/inet.h> 21 22 #ifdef WITH_OPENSSL 23 #include <openssl/bn.h> 24 #endif 25 26 #include <limits.h> 27 #include <netdb.h> 28 #include <errno.h> 29 #ifdef HAVE_POLL_H 30 #include <poll.h> 31 #endif 32 #include <stdarg.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <signal.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #include "xmalloc.h" 40 #include "ssh.h" 41 #include "sshbuf.h" 42 #include "sshkey.h" 43 #include "cipher.h" 44 #include "digest.h" 45 #include "kex.h" 46 #include "compat.h" 47 #include "myproposal.h" 48 #include "packet.h" 49 #include "dispatch.h" 50 #include "log.h" 51 #include "atomicio.h" 52 #include "misc.h" 53 #include "hostfile.h" 54 #include "ssherr.h" 55 #include "ssh_api.h" 56 #include "dns.h" 57 #include "addr.h" 58 59 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line. 60 Default value is AF_UNSPEC means both IPv4 and IPv6. */ 61 int IPv4or6 = AF_UNSPEC; 62 63 int ssh_port = SSH_DEFAULT_PORT; 64 65 #define KT_DSA (1) 66 #define KT_RSA (1<<1) 67 #define KT_ECDSA (1<<2) 68 #define KT_ED25519 (1<<3) 69 #define KT_XMSS (1<<4) 70 #define KT_ECDSA_SK (1<<5) 71 #define KT_ED25519_SK (1<<6) 72 73 #define KT_MIN KT_DSA 74 #define KT_MAX KT_ED25519_SK 75 76 int get_cert = 0; 77 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519|KT_ECDSA_SK|KT_ED25519_SK; 78 79 int hash_hosts = 0; /* Hash hostname on output */ 80 81 int print_sshfp = 0; /* Print SSHFP records instead of known_hosts */ 82 83 int found_one = 0; /* Successfully found a key */ 84 85 int hashalg = -1; /* Hash for SSHFP records or -1 for all */ 86 87 #define MAXMAXFD 256 88 89 /* The number of seconds after which to give up on a TCP connection */ 90 int timeout = 5; 91 92 int maxfd; 93 #define MAXCON (maxfd - 10) 94 95 extern char *__progname; 96 struct pollfd *read_wait; 97 int ncon; 98 99 /* 100 * Keep a connection structure for each file descriptor. The state 101 * associated with file descriptor n is held in fdcon[n]. 102 */ 103 typedef struct Connection { 104 u_char c_status; /* State of connection on this file desc. */ 105 #define CS_UNUSED 0 /* File descriptor unused */ 106 #define CS_CON 1 /* Waiting to connect/read greeting */ 107 #define CS_SIZE 2 /* Waiting to read initial packet size */ 108 #define CS_KEYS 3 /* Waiting to read public key packet */ 109 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */ 110 int c_plen; /* Packet length field for ssh packet */ 111 int c_len; /* Total bytes which must be read. */ 112 int c_off; /* Length of data read so far. */ 113 int c_keytype; /* Only one of KT_* */ 114 sig_atomic_t c_done; /* SSH2 done */ 115 char *c_namebase; /* Address to free for c_name and c_namelist */ 116 char *c_name; /* Hostname of connection for errors */ 117 char *c_namelist; /* Pointer to other possible addresses */ 118 char *c_output_name; /* Hostname of connection for output */ 119 char *c_data; /* Data read from this fd */ 120 struct ssh *c_ssh; /* SSH-connection */ 121 struct timespec c_ts; /* Time at which connection gets aborted */ 122 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */ 123 } con; 124 125 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */ 126 con *fdcon; 127 128 static void keyprint(con *c, struct sshkey *key); 129 130 static int 131 fdlim_get(int hard) 132 { 133 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE) 134 struct rlimit rlfd; 135 rlim_t lim; 136 137 if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1) 138 return -1; 139 lim = hard ? rlfd.rlim_max : rlfd.rlim_cur; 140 if (lim <= 0) 141 return -1; 142 if (lim == RLIM_INFINITY) 143 lim = SSH_SYSFDMAX; 144 if (lim >= INT_MAX) 145 lim = INT_MAX; 146 return lim; 147 #else 148 return (SSH_SYSFDMAX <= 0) ? -1 : 149 ((SSH_SYSFDMAX >= INT_MAX) ? INT_MAX : SSH_SYSFDMAX); 150 #endif 151 } 152 153 static int 154 fdlim_set(int lim) 155 { 156 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE) 157 struct rlimit rlfd; 158 #endif 159 160 if (lim <= 0) 161 return (-1); 162 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE) 163 if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1) 164 return (-1); 165 rlfd.rlim_cur = lim; 166 if (setrlimit(RLIMIT_NOFILE, &rlfd) == -1) 167 return (-1); 168 #elif defined (HAVE_SETDTABLESIZE) 169 setdtablesize(lim); 170 #endif 171 return (0); 172 } 173 174 /* 175 * This is an strsep function that returns a null field for adjacent 176 * separators. This is the same as the 4.4BSD strsep, but different from the 177 * one in the GNU libc. 178 */ 179 static char * 180 xstrsep(char **str, const char *delim) 181 { 182 char *s, *e; 183 184 if (!**str) 185 return (NULL); 186 187 s = *str; 188 e = s + strcspn(s, delim); 189 190 if (*e != '\0') 191 *e++ = '\0'; 192 *str = e; 193 194 return (s); 195 } 196 197 /* 198 * Get the next non-null token (like GNU strsep). Strsep() will return a 199 * null token for two adjacent separators, so we may have to loop. 200 */ 201 static char * 202 strnnsep(char **stringp, char *delim) 203 { 204 char *tok; 205 206 do { 207 tok = xstrsep(stringp, delim); 208 } while (tok && *tok == '\0'); 209 return (tok); 210 } 211 212 213 static int 214 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh) 215 { 216 con *c; 217 218 if ((c = ssh_get_app_data(ssh)) != NULL) 219 keyprint(c, hostkey); 220 /* always abort key exchange */ 221 return -1; 222 } 223 224 static int 225 ssh2_capable(int remote_major, int remote_minor) 226 { 227 switch (remote_major) { 228 case 1: 229 if (remote_minor == 99) 230 return 1; 231 break; 232 case 2: 233 return 1; 234 default: 235 break; 236 } 237 return 0; 238 } 239 240 static void 241 keygrab_ssh2(con *c) 242 { 243 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT }; 244 int r; 245 246 switch (c->c_keytype) { 247 case KT_DSA: 248 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 249 "ssh-dss-cert-v01@openssh.com" : "ssh-dss"; 250 break; 251 case KT_RSA: 252 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 253 "rsa-sha2-512-cert-v01@openssh.com," 254 "rsa-sha2-256-cert-v01@openssh.com," 255 "ssh-rsa-cert-v01@openssh.com" : 256 "rsa-sha2-512," 257 "rsa-sha2-256," 258 "ssh-rsa"; 259 break; 260 case KT_ED25519: 261 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 262 "ssh-ed25519-cert-v01@openssh.com" : "ssh-ed25519"; 263 break; 264 case KT_XMSS: 265 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 266 "ssh-xmss-cert-v01@openssh.com" : "ssh-xmss@openssh.com"; 267 break; 268 case KT_ECDSA: 269 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 270 "ecdsa-sha2-nistp256-cert-v01@openssh.com," 271 "ecdsa-sha2-nistp384-cert-v01@openssh.com," 272 "ecdsa-sha2-nistp521-cert-v01@openssh.com" : 273 "ecdsa-sha2-nistp256," 274 "ecdsa-sha2-nistp384," 275 "ecdsa-sha2-nistp521"; 276 break; 277 case KT_ECDSA_SK: 278 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 279 "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com" : 280 "sk-ecdsa-sha2-nistp256@openssh.com"; 281 break; 282 case KT_ED25519_SK: 283 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ? 284 "sk-ssh-ed25519-cert-v01@openssh.com" : 285 "sk-ssh-ed25519@openssh.com"; 286 break; 287 default: 288 fatal("unknown key type %d", c->c_keytype); 289 break; 290 } 291 if ((r = kex_setup(c->c_ssh, myproposal)) != 0) { 292 free(c->c_ssh); 293 fprintf(stderr, "kex_setup: %s\n", ssh_err(r)); 294 exit(1); 295 } 296 #ifdef WITH_OPENSSL 297 c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client; 298 c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client; 299 c->c_ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client; 300 c->c_ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client; 301 c->c_ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client; 302 c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; 303 c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; 304 # ifdef OPENSSL_HAS_ECC 305 c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client; 306 # endif 307 #endif 308 c->c_ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client; 309 c->c_ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client; 310 ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper); 311 /* 312 * do the key-exchange until an error occurs or until 313 * the key_print_wrapper() callback sets c_done. 314 */ 315 ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done); 316 } 317 318 static void 319 keyprint_one(const char *host, struct sshkey *key) 320 { 321 char *hostport = NULL, *hashed = NULL; 322 const char *known_host; 323 int r = 0; 324 325 found_one = 1; 326 327 if (print_sshfp) { 328 export_dns_rr(host, key, stdout, 0, hashalg); 329 return; 330 } 331 332 hostport = put_host_port(host, ssh_port); 333 lowercase(hostport); 334 if (hash_hosts && (hashed = host_hash(hostport, NULL, 0)) == NULL) 335 fatal("host_hash failed"); 336 known_host = hash_hosts ? hashed : hostport; 337 if (!get_cert) 338 r = fprintf(stdout, "%s ", known_host); 339 if (r >= 0 && sshkey_write(key, stdout) == 0) 340 (void)fputs("\n", stdout); 341 free(hashed); 342 free(hostport); 343 } 344 345 static void 346 keyprint(con *c, struct sshkey *key) 347 { 348 char *hosts = c->c_output_name ? c->c_output_name : c->c_name; 349 char *host, *ohosts; 350 351 if (key == NULL) 352 return; 353 if (get_cert || (!hash_hosts && ssh_port == SSH_DEFAULT_PORT)) { 354 keyprint_one(hosts, key); 355 return; 356 } 357 ohosts = hosts = xstrdup(hosts); 358 while ((host = strsep(&hosts, ",")) != NULL) 359 keyprint_one(host, key); 360 free(ohosts); 361 } 362 363 static int 364 tcpconnect(char *host) 365 { 366 struct addrinfo hints, *ai, *aitop; 367 char strport[NI_MAXSERV]; 368 int gaierr, s = -1; 369 370 snprintf(strport, sizeof strport, "%d", ssh_port); 371 memset(&hints, 0, sizeof(hints)); 372 hints.ai_family = IPv4or6; 373 hints.ai_socktype = SOCK_STREAM; 374 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { 375 error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr)); 376 return -1; 377 } 378 for (ai = aitop; ai; ai = ai->ai_next) { 379 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); 380 if (s == -1) { 381 error("socket: %s", strerror(errno)); 382 continue; 383 } 384 if (set_nonblock(s) == -1) 385 fatal_f("set_nonblock(%d)", s); 386 if (connect(s, ai->ai_addr, ai->ai_addrlen) == -1 && 387 errno != EINPROGRESS) 388 error("connect (`%s'): %s", host, strerror(errno)); 389 else 390 break; 391 close(s); 392 s = -1; 393 } 394 freeaddrinfo(aitop); 395 return s; 396 } 397 398 static int 399 conalloc(const char *iname, const char *oname, int keytype) 400 { 401 char *namebase, *name, *namelist; 402 int s; 403 404 namebase = namelist = xstrdup(iname); 405 406 do { 407 name = xstrsep(&namelist, ","); 408 if (!name) { 409 free(namebase); 410 return (-1); 411 } 412 } while ((s = tcpconnect(name)) < 0); 413 414 if (s >= maxfd) 415 fatal("conalloc: fdno %d too high", s); 416 if (fdcon[s].c_status) 417 fatal("conalloc: attempt to reuse fdno %d", s); 418 419 debug3_f("oname %s kt %d", oname, keytype); 420 fdcon[s].c_fd = s; 421 fdcon[s].c_status = CS_CON; 422 fdcon[s].c_namebase = namebase; 423 fdcon[s].c_name = name; 424 fdcon[s].c_namelist = namelist; 425 fdcon[s].c_output_name = xstrdup(oname); 426 fdcon[s].c_data = (char *) &fdcon[s].c_plen; 427 fdcon[s].c_len = 4; 428 fdcon[s].c_off = 0; 429 fdcon[s].c_keytype = keytype; 430 monotime_ts(&fdcon[s].c_ts); 431 fdcon[s].c_ts.tv_sec += timeout; 432 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link); 433 read_wait[s].fd = s; 434 read_wait[s].events = POLLIN; 435 ncon++; 436 return (s); 437 } 438 439 static void 440 confree(int s) 441 { 442 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED) 443 fatal("confree: attempt to free bad fdno %d", s); 444 free(fdcon[s].c_namebase); 445 free(fdcon[s].c_output_name); 446 if (fdcon[s].c_status == CS_KEYS) 447 free(fdcon[s].c_data); 448 fdcon[s].c_status = CS_UNUSED; 449 fdcon[s].c_keytype = 0; 450 if (fdcon[s].c_ssh) { 451 ssh_packet_close(fdcon[s].c_ssh); 452 free(fdcon[s].c_ssh); 453 fdcon[s].c_ssh = NULL; 454 } else 455 close(s); 456 TAILQ_REMOVE(&tq, &fdcon[s], c_link); 457 read_wait[s].fd = -1; 458 read_wait[s].events = 0; 459 ncon--; 460 } 461 462 static void 463 contouch(int s) 464 { 465 TAILQ_REMOVE(&tq, &fdcon[s], c_link); 466 monotime_ts(&fdcon[s].c_ts); 467 fdcon[s].c_ts.tv_sec += timeout; 468 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link); 469 } 470 471 static int 472 conrecycle(int s) 473 { 474 con *c = &fdcon[s]; 475 int ret; 476 477 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype); 478 confree(s); 479 return (ret); 480 } 481 482 static void 483 congreet(int s) 484 { 485 int n = 0, remote_major = 0, remote_minor = 0; 486 char buf[256], *cp; 487 char remote_version[sizeof buf]; 488 size_t bufsiz; 489 con *c = &fdcon[s]; 490 491 /* send client banner */ 492 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n", 493 PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2); 494 if (n < 0 || (size_t)n >= sizeof(buf)) { 495 error("snprintf: buffer too small"); 496 confree(s); 497 return; 498 } 499 if (atomicio(vwrite, s, buf, n) != (size_t)n) { 500 error("write (%s): %s", c->c_name, strerror(errno)); 501 confree(s); 502 return; 503 } 504 505 /* 506 * Read the server banner as per RFC4253 section 4.2. The "SSH-" 507 * protocol identification string may be preceeded by an arbitrarily 508 * large banner which we must read and ignore. Loop while reading 509 * newline-terminated lines until we have one starting with "SSH-". 510 * The ID string cannot be longer than 255 characters although the 511 * preceeding banner lines may (in which case they'll be discarded 512 * in multiple iterations of the outer loop). 513 */ 514 for (;;) { 515 memset(buf, '\0', sizeof(buf)); 516 bufsiz = sizeof(buf); 517 cp = buf; 518 while (bufsiz-- && 519 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') { 520 if (*cp == '\r') 521 *cp = '\n'; 522 cp++; 523 } 524 if (n != 1 || strncmp(buf, "SSH-", 4) == 0) 525 break; 526 } 527 if (n == 0) { 528 switch (errno) { 529 case EPIPE: 530 error("%s: Connection closed by remote host", c->c_name); 531 break; 532 case ECONNREFUSED: 533 break; 534 default: 535 error("read (%s): %s", c->c_name, strerror(errno)); 536 break; 537 } 538 conrecycle(s); 539 return; 540 } 541 if (cp >= buf + sizeof(buf)) { 542 error("%s: greeting exceeds allowable length", c->c_name); 543 confree(s); 544 return; 545 } 546 if (*cp != '\n' && *cp != '\r') { 547 error("%s: bad greeting", c->c_name); 548 confree(s); 549 return; 550 } 551 *cp = '\0'; 552 if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL) 553 fatal("ssh_packet_set_connection failed"); 554 ssh_packet_set_timeout(c->c_ssh, timeout, 1); 555 ssh_set_app_data(c->c_ssh, c); /* back link */ 556 c->c_ssh->compat = 0; 557 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", 558 &remote_major, &remote_minor, remote_version) == 3) 559 compat_banner(c->c_ssh, remote_version); 560 if (!ssh2_capable(remote_major, remote_minor)) { 561 debug("%s doesn't support ssh2", c->c_name); 562 confree(s); 563 return; 564 } 565 fprintf(stderr, "%c %s:%d %s\n", print_sshfp ? ';' : '#', 566 c->c_name, ssh_port, chop(buf)); 567 keygrab_ssh2(c); 568 confree(s); 569 } 570 571 static void 572 conread(int s) 573 { 574 con *c = &fdcon[s]; 575 size_t n; 576 577 if (c->c_status == CS_CON) { 578 congreet(s); 579 return; 580 } 581 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off); 582 if (n == 0) { 583 error("read (%s): %s", c->c_name, strerror(errno)); 584 confree(s); 585 return; 586 } 587 c->c_off += n; 588 589 if (c->c_off == c->c_len) 590 switch (c->c_status) { 591 case CS_SIZE: 592 c->c_plen = htonl(c->c_plen); 593 c->c_len = c->c_plen + 8 - (c->c_plen & 7); 594 c->c_off = 0; 595 c->c_data = xmalloc(c->c_len); 596 c->c_status = CS_KEYS; 597 break; 598 default: 599 fatal("conread: invalid status %d", c->c_status); 600 break; 601 } 602 603 contouch(s); 604 } 605 606 static void 607 conloop(void) 608 { 609 struct timespec seltime, now; 610 con *c; 611 int i; 612 613 monotime_ts(&now); 614 c = TAILQ_FIRST(&tq); 615 616 if (c && timespeccmp(&c->c_ts, &now, >)) 617 timespecsub(&c->c_ts, &now, &seltime); 618 else 619 timespecclear(&seltime); 620 621 while (ppoll(read_wait, maxfd, &seltime, NULL) == -1) { 622 if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK) 623 continue; 624 error("poll error"); 625 } 626 627 for (i = 0; i < maxfd; i++) { 628 if (read_wait[i].revents & (POLLHUP|POLLERR|POLLNVAL)) 629 confree(i); 630 else if (read_wait[i].revents & (POLLIN|POLLHUP)) 631 conread(i); 632 } 633 634 c = TAILQ_FIRST(&tq); 635 while (c && timespeccmp(&c->c_ts, &now, <)) { 636 int s = c->c_fd; 637 638 c = TAILQ_NEXT(c, c_link); 639 conrecycle(s); 640 } 641 } 642 643 static void 644 do_one_host(char *host) 645 { 646 char *name = strnnsep(&host, " \t\n"); 647 int j; 648 649 if (name == NULL) 650 return; 651 for (j = KT_MIN; j <= KT_MAX; j *= 2) { 652 if (get_keytypes & j) { 653 while (ncon >= MAXCON) 654 conloop(); 655 conalloc(name, *host ? host : name, j); 656 } 657 } 658 } 659 660 static void 661 do_host(char *host) 662 { 663 char daddr[128]; 664 struct xaddr addr, end_addr; 665 u_int masklen; 666 667 if (host == NULL) 668 return; 669 if (addr_pton_cidr(host, &addr, &masklen) != 0) { 670 /* Assume argument is a hostname */ 671 do_one_host(host); 672 } else { 673 /* Argument is a CIDR range */ 674 debug("CIDR range %s", host); 675 end_addr = addr; 676 if (addr_host_to_all1s(&end_addr, masklen) != 0) 677 goto badaddr; 678 /* 679 * Note: we deliberately include the all-zero/ones addresses. 680 */ 681 for (;;) { 682 if (addr_ntop(&addr, daddr, sizeof(daddr)) != 0) { 683 badaddr: 684 error("Invalid address %s", host); 685 return; 686 } 687 debug("CIDR expand: address %s", daddr); 688 do_one_host(daddr); 689 if (addr_cmp(&addr, &end_addr) == 0) 690 break; 691 addr_increment(&addr); 692 }; 693 } 694 } 695 696 void 697 sshfatal(const char *file, const char *func, int line, int showfunc, 698 LogLevel level, const char *suffix, const char *fmt, ...) 699 { 700 va_list args; 701 702 va_start(args, fmt); 703 sshlogv(file, func, line, showfunc, level, suffix, fmt, args); 704 va_end(args); 705 cleanup_exit(255); 706 } 707 708 static void 709 usage(void) 710 { 711 fprintf(stderr, 712 "usage: ssh-keyscan [-46cDHv] [-f file] [-O option] [-p port] [-T timeout]\n" 713 " [-t type] [host | addrlist namelist]\n"); 714 exit(1); 715 } 716 717 int 718 main(int argc, char **argv) 719 { 720 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO; 721 int opt, fopt_count = 0, j; 722 char *tname, *cp, *line = NULL; 723 size_t linesize = 0; 724 FILE *fp; 725 726 extern int optind; 727 extern char *optarg; 728 729 __progname = ssh_get_progname(argv[0]); 730 seed_rng(); 731 TAILQ_INIT(&tq); 732 733 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 734 sanitise_stdfd(); 735 736 if (argc <= 1) 737 usage(); 738 739 while ((opt = getopt(argc, argv, "cDHv46O:p:T:t:f:")) != -1) { 740 switch (opt) { 741 case 'H': 742 hash_hosts = 1; 743 break; 744 case 'c': 745 get_cert = 1; 746 break; 747 case 'D': 748 print_sshfp = 1; 749 break; 750 case 'p': 751 ssh_port = a2port(optarg); 752 if (ssh_port <= 0) { 753 fprintf(stderr, "Bad port '%s'\n", optarg); 754 exit(1); 755 } 756 break; 757 case 'T': 758 timeout = convtime(optarg); 759 if (timeout == -1 || timeout == 0) { 760 fprintf(stderr, "Bad timeout '%s'\n", optarg); 761 usage(); 762 } 763 break; 764 case 'v': 765 if (!debug_flag) { 766 debug_flag = 1; 767 log_level = SYSLOG_LEVEL_DEBUG1; 768 } 769 else if (log_level < SYSLOG_LEVEL_DEBUG3) 770 log_level++; 771 else 772 fatal("Too high debugging level."); 773 break; 774 case 'f': 775 if (strcmp(optarg, "-") == 0) 776 optarg = NULL; 777 argv[fopt_count++] = optarg; 778 break; 779 case 'O': 780 /* Maybe other misc options in the future too */ 781 if (strncmp(optarg, "hashalg=", 8) != 0) 782 fatal("Unsupported -O option"); 783 if ((hashalg = ssh_digest_alg_by_name( 784 optarg + 8)) == -1) 785 fatal("Unsupported hash algorithm"); 786 break; 787 case 't': 788 get_keytypes = 0; 789 tname = strtok(optarg, ","); 790 while (tname) { 791 int type = sshkey_type_from_name(tname); 792 793 switch (type) { 794 case KEY_DSA: 795 get_keytypes |= KT_DSA; 796 break; 797 case KEY_ECDSA: 798 get_keytypes |= KT_ECDSA; 799 break; 800 case KEY_RSA: 801 get_keytypes |= KT_RSA; 802 break; 803 case KEY_ED25519: 804 get_keytypes |= KT_ED25519; 805 break; 806 case KEY_XMSS: 807 get_keytypes |= KT_XMSS; 808 break; 809 case KEY_ED25519_SK: 810 get_keytypes |= KT_ED25519_SK; 811 break; 812 case KEY_ECDSA_SK: 813 get_keytypes |= KT_ECDSA_SK; 814 break; 815 case KEY_UNSPEC: 816 default: 817 fatal("Unknown key type \"%s\"", tname); 818 } 819 tname = strtok(NULL, ","); 820 } 821 break; 822 case '4': 823 IPv4or6 = AF_INET; 824 break; 825 case '6': 826 IPv4or6 = AF_INET6; 827 break; 828 default: 829 usage(); 830 } 831 } 832 if (optind == argc && !fopt_count) 833 usage(); 834 835 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1); 836 837 maxfd = fdlim_get(1); 838 if (maxfd < 0) 839 fatal("%s: fdlim_get: bad value", __progname); 840 if (maxfd > MAXMAXFD) 841 maxfd = MAXMAXFD; 842 if (MAXCON <= 0) 843 fatal("%s: not enough file descriptors", __progname); 844 if (maxfd > fdlim_get(0)) 845 fdlim_set(maxfd); 846 fdcon = xcalloc(maxfd, sizeof(con)); 847 read_wait = xcalloc(maxfd, sizeof(struct pollfd)); 848 for (j = 0; j < maxfd; j++) 849 read_wait[j].fd = -1; 850 851 for (j = 0; j < fopt_count; j++) { 852 if (argv[j] == NULL) 853 fp = stdin; 854 else if ((fp = fopen(argv[j], "r")) == NULL) 855 fatal("%s: %s: %s", __progname, argv[j], strerror(errno)); 856 857 while (getline(&line, &linesize, fp) != -1) { 858 /* Chomp off trailing whitespace and comments */ 859 if ((cp = strchr(line, '#')) == NULL) 860 cp = line + strlen(line) - 1; 861 while (cp >= line) { 862 if (*cp == ' ' || *cp == '\t' || 863 *cp == '\n' || *cp == '#') 864 *cp-- = '\0'; 865 else 866 break; 867 } 868 869 /* Skip empty lines */ 870 if (*line == '\0') 871 continue; 872 873 do_host(line); 874 } 875 876 if (ferror(fp)) 877 fatal("%s: %s: %s", __progname, argv[j], strerror(errno)); 878 879 fclose(fp); 880 } 881 free(line); 882 883 while (optind < argc) 884 do_host(argv[optind++]); 885 886 while (ncon > 0) 887 conloop(); 888 889 return found_one ? 0 : 1; 890 } 891