xref: /netbsd-src/crypto/external/bsd/openssh/dist/ssh-keyscan.c (revision 9469f4f13c84743995b7d51c506f9c9849ba30de) 
1 /*	$NetBSD: ssh-keyscan.c,v 1.35 2024/09/24 21:32:19 christos Exp $	*/
2 /* $OpenBSD: ssh-keyscan.c,v 1.161 2024/09/09 02:39:57 djm Exp $ */
3 
4 /*
5  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
6  *
7  * Modification and redistribution in source and binary forms is
8  * permitted provided that due credit is given to the author and the
9  * OpenBSD project by leaving this copyright notice intact.
10  */
11 
12 #include "includes.h"
13 __RCSID("$NetBSD: ssh-keyscan.c,v 1.35 2024/09/24 21:32:19 christos Exp $");
14 
15 #include <sys/param.h>
16 #include <sys/types.h>
17 #include <sys/socket.h>
18 #include <sys/queue.h>
19 #include <sys/time.h>
20 #include <sys/resource.h>
21 
22 #ifdef WITH_OPENSSL
23 #include <openssl/bn.h>
24 #endif
25 
26 #include <errno.h>
27 #include <limits.h>
28 #include <netdb.h>
29 #include <stdarg.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <poll.h>
33 #include <signal.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 #include "xmalloc.h"
38 #include "ssh.h"
39 #include "sshbuf.h"
40 #include "sshkey.h"
41 #include "cipher.h"
42 #include "digest.h"
43 #include "kex.h"
44 #include "compat.h"
45 #include "myproposal.h"
46 #include "packet.h"
47 #include "dispatch.h"
48 #include "log.h"
49 #include "atomicio.h"
50 #include "misc.h"
51 #include "hostfile.h"
52 #include "ssherr.h"
53 #include "ssh_api.h"
54 #include "dns.h"
55 #include "addr.h"
56 #include "fmt_scaled.h"
57 
58 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
59    Default value is AF_UNSPEC means both IPv4 and IPv6. */
60 int IPv4or6 = AF_UNSPEC;
61 
62 int ssh_port = SSH_DEFAULT_PORT;
63 
64 #define KT_DSA		(1)
65 #define KT_RSA		(1<<1)
66 #define KT_ECDSA	(1<<2)
67 #define KT_ED25519	(1<<3)
68 #define KT_XMSS		(1<<4)
69 #define KT_ECDSA_SK	(1<<5)
70 #define KT_ED25519_SK	(1<<6)
71 
72 #define KT_MIN		KT_DSA
73 #define KT_MAX		KT_ED25519_SK
74 
75 int get_cert = 0;
76 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519|KT_ECDSA_SK|KT_ED25519_SK;
77 
78 int hash_hosts = 0;		/* Hash hostname on output */
79 
80 int print_sshfp = 0;		/* Print SSHFP records instead of known_hosts */
81 
82 int found_one = 0;		/* Successfully found a key */
83 
84 int hashalg = -1;		/* Hash for SSHFP records or -1 for all */
85 
86 int quiet = 0;			/* Don't print key comment lines */
87 
88 #define MAXMAXFD 256
89 
90 /* The number of seconds after which to give up on a TCP connection */
91 int timeout = 5;
92 
93 int maxfd;
94 #define MAXCON (maxfd - 10)
95 
96 extern char *__progname;
97 struct pollfd *read_wait;
98 int ncon;
99 
100 /*
101  * Keep a connection structure for each file descriptor.  The state
102  * associated with file descriptor n is held in fdcon[n].
103  */
104 typedef struct Connection {
105 	u_char c_status;	/* State of connection on this file desc. */
106 #define CS_UNUSED 0		/* File descriptor unused */
107 #define CS_CON 1		/* Waiting to connect/read greeting */
108 	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
109 	int c_keytype;		/* Only one of KT_* */
110 	sig_atomic_t c_done;	/* SSH2 done */
111 	char *c_namebase;	/* Address to free for c_name and c_namelist */
112 	char *c_name;		/* Hostname of connection for errors */
113 	char *c_namelist;	/* Pointer to other possible addresses */
114 	char *c_output_name;	/* Hostname of connection for output */
115 	struct ssh *c_ssh;	/* SSH-connection */
116 	struct timespec c_ts;	/* Time at which connection gets aborted */
117 	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
118 } con;
119 
120 TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
121 con *fdcon;
122 
123 static void keyprint(con *c, struct sshkey *key);
124 
125 static int
126 fdlim_get(int hard)
127 {
128 	struct rlimit rlfd;
129 
130 	if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1)
131 		return (-1);
132 	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY ||
133 	    (hard ? rlfd.rlim_max : rlfd.rlim_cur) > INT_MAX)
134 		return sysconf(_SC_OPEN_MAX);
135 	return hard ? rlfd.rlim_max : rlfd.rlim_cur;
136 }
137 
138 static int
139 fdlim_set(int lim)
140 {
141 	struct rlimit rlfd;
142 
143 	if (lim <= 0)
144 		return (-1);
145 	if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1)
146 		return (-1);
147 	rlfd.rlim_cur = lim;
148 	if (setrlimit(RLIMIT_NOFILE, &rlfd) == -1)
149 		return (-1);
150 	return (0);
151 }
152 
153 /*
154  * This is an strsep function that returns a null field for adjacent
155  * separators.  This is the same as the 4.4BSD strsep, but different from the
156  * one in the GNU libc.
157  */
158 static char *
159 xstrsep(char **str, const char *delim)
160 {
161 	char *s, *e;
162 
163 	if (!**str)
164 		return (NULL);
165 
166 	s = *str;
167 	e = s + strcspn(s, delim);
168 
169 	if (*e != '\0')
170 		*e++ = '\0';
171 	*str = e;
172 
173 	return (s);
174 }
175 
176 /*
177  * Get the next non-null token (like GNU strsep).  Strsep() will return a
178  * null token for two adjacent separators, so we may have to loop.
179  */
180 static char *
181 strnnsep(char **stringp, const char *delim)
182 {
183 	char *tok;
184 
185 	do {
186 		tok = xstrsep(stringp, delim);
187 	} while (tok && *tok == '\0');
188 	return (tok);
189 }
190 
191 
192 static int
193 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh)
194 {
195 	con *c;
196 
197 	if ((c = ssh_get_app_data(ssh)) != NULL)
198 		keyprint(c, hostkey);
199 	/* always abort key exchange */
200 	return -1;
201 }
202 
203 static int
204 ssh2_capable(int remote_major, int remote_minor)
205 {
206 	switch (remote_major) {
207 	case 1:
208 		if (remote_minor == 99)
209 			return 1;
210 		break;
211 	case 2:
212 		return 1;
213 	default:
214 		break;
215 	}
216 	return 0;
217 }
218 
219 static void
220 keygrab_ssh2(con *c)
221 {
222 	const char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
223 	int r;
224 
225 	switch (c->c_keytype) {
226 	case KT_DSA:
227 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
228 		    "ssh-dss-cert-v01@openssh.com" : "ssh-dss";
229 		break;
230 	case KT_RSA:
231 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
232 		    "rsa-sha2-512-cert-v01@openssh.com,"
233 		    "rsa-sha2-256-cert-v01@openssh.com,"
234 		    "ssh-rsa-cert-v01@openssh.com" :
235 		    "rsa-sha2-512,"
236 		    "rsa-sha2-256,"
237 		    "ssh-rsa";
238 		break;
239 	case KT_ED25519:
240 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
241 		    "ssh-ed25519-cert-v01@openssh.com" : "ssh-ed25519";
242 		break;
243 	case KT_XMSS:
244 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
245 		    "ssh-xmss-cert-v01@openssh.com" : "ssh-xmss@openssh.com";
246 		break;
247 	case KT_ECDSA:
248 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
249 		    "ecdsa-sha2-nistp256-cert-v01@openssh.com,"
250 		    "ecdsa-sha2-nistp384-cert-v01@openssh.com,"
251 		    "ecdsa-sha2-nistp521-cert-v01@openssh.com" :
252 		    "ecdsa-sha2-nistp256,"
253 		    "ecdsa-sha2-nistp384,"
254 		    "ecdsa-sha2-nistp521";
255 		break;
256 	case KT_ECDSA_SK:
257 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
258 		    "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com" :
259 		    "sk-ecdsa-sha2-nistp256@openssh.com";
260 		break;
261 	case KT_ED25519_SK:
262 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
263 		    "sk-ssh-ed25519-cert-v01@openssh.com" :
264 		    "sk-ssh-ed25519@openssh.com";
265 		break;
266 	default:
267 		fatal("unknown key type %d", c->c_keytype);
268 		break;
269 	}
270 	if ((r = kex_setup(c->c_ssh, __UNCONST(myproposal))) != 0) {
271 		free(c->c_ssh);
272 		fprintf(stderr, "kex_setup: %s\n", ssh_err(r));
273 		exit(1);
274 	}
275 #ifdef WITH_OPENSSL
276 	c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
277 	c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
278 	c->c_ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
279 	c->c_ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
280 	c->c_ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
281 	c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
282 	c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
283 	c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
284 #endif
285 	c->c_ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
286 	c->c_ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
287 	c->c_ssh->kex->kex[KEX_KEM_MLKEM768X25519_SHA256] = kex_gen_client;
288 	ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
289 	/*
290 	 * do the key-exchange until an error occurs or until
291 	 * the key_print_wrapper() callback sets c_done.
292 	 */
293 	ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done);
294 }
295 
296 static void
297 keyprint_one(const char *host, struct sshkey *key)
298 {
299 	char *hostport = NULL, *hashed = NULL;
300 	const char *known_host;
301 	int r = 0;
302 
303 	found_one = 1;
304 
305 	if (print_sshfp) {
306 		export_dns_rr(host, key, stdout, 0, hashalg);
307 		return;
308 	}
309 
310 	hostport = put_host_port(host, ssh_port);
311 	lowercase(hostport);
312 	if (hash_hosts && (hashed = host_hash(hostport, NULL, 0)) == NULL)
313 		fatal("host_hash failed");
314 	known_host = hash_hosts ? hashed : hostport;
315 	if (!get_cert)
316 		r = fprintf(stdout, "%s ", known_host);
317 	if (r >= 0 && sshkey_write(key, stdout) == 0)
318 		(void)fputs("\n", stdout);
319 	free(hashed);
320 	free(hostport);
321 }
322 
323 static void
324 keyprint(con *c, struct sshkey *key)
325 {
326 	char *hosts = c->c_output_name ? c->c_output_name : c->c_name;
327 	char *host, *ohosts;
328 
329 	if (key == NULL)
330 		return;
331 	if (get_cert || (!hash_hosts && ssh_port == SSH_DEFAULT_PORT)) {
332 		keyprint_one(hosts, key);
333 		return;
334 	}
335 	ohosts = hosts = xstrdup(hosts);
336 	while ((host = strsep(&hosts, ",")) != NULL)
337 		keyprint_one(host, key);
338 	free(ohosts);
339 }
340 
341 static int
342 tcpconnect(char *host)
343 {
344 	struct addrinfo hints, *ai, *aitop;
345 	char strport[NI_MAXSERV];
346 	int gaierr, s = -1;
347 
348 	snprintf(strport, sizeof strport, "%d", ssh_port);
349 	memset(&hints, 0, sizeof(hints));
350 	hints.ai_family = IPv4or6;
351 	hints.ai_socktype = SOCK_STREAM;
352 	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
353 		error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
354 		return -1;
355 	}
356 	for (ai = aitop; ai; ai = ai->ai_next) {
357 		s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
358 		if (s == -1) {
359 			error("socket: %s", strerror(errno));
360 			continue;
361 		}
362 		if (set_nonblock(s) == -1)
363 			fatal_f("set_nonblock(%d)", s);
364 		if (connect(s, ai->ai_addr, ai->ai_addrlen) == -1 &&
365 		    errno != EINPROGRESS)
366 			error("connect (`%s'): %s", host, strerror(errno));
367 		else
368 			break;
369 		close(s);
370 		s = -1;
371 	}
372 	freeaddrinfo(aitop);
373 	return s;
374 }
375 
376 static int
377 conalloc(const char *iname, const char *oname, int keytype)
378 {
379 	char *namebase, *name, *namelist;
380 	int s;
381 
382 	namebase = namelist = xstrdup(iname);
383 
384 	do {
385 		name = xstrsep(&namelist, ",");
386 		if (!name) {
387 			free(namebase);
388 			return (-1);
389 		}
390 	} while ((s = tcpconnect(name)) < 0);
391 
392 	if (s >= maxfd)
393 		fatal("conalloc: fdno %d too high", s);
394 	if (fdcon[s].c_status)
395 		fatal("conalloc: attempt to reuse fdno %d", s);
396 
397 	debug3_f("oname %s kt %d", oname, keytype);
398 	fdcon[s].c_fd = s;
399 	fdcon[s].c_status = CS_CON;
400 	fdcon[s].c_namebase = namebase;
401 	fdcon[s].c_name = name;
402 	fdcon[s].c_namelist = namelist;
403 	fdcon[s].c_output_name = xstrdup(oname);
404 	fdcon[s].c_keytype = keytype;
405 	monotime_ts(&fdcon[s].c_ts);
406 	fdcon[s].c_ts.tv_sec += timeout;
407 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
408 	read_wait[s].fd = s;
409 	read_wait[s].events = POLLIN;
410 	ncon++;
411 	return (s);
412 }
413 
414 static void
415 confree(int s)
416 {
417 	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
418 		fatal("confree: attempt to free bad fdno %d", s);
419 	free(fdcon[s].c_namebase);
420 	free(fdcon[s].c_output_name);
421 	fdcon[s].c_status = CS_UNUSED;
422 	fdcon[s].c_keytype = 0;
423 	if (fdcon[s].c_ssh) {
424 		ssh_packet_close(fdcon[s].c_ssh);
425 		free(fdcon[s].c_ssh);
426 		fdcon[s].c_ssh = NULL;
427 	} else
428 		close(s);
429 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
430 	read_wait[s].fd = -1;
431 	read_wait[s].events = 0;
432 	ncon--;
433 }
434 
435 static int
436 conrecycle(int s)
437 {
438 	con *c = &fdcon[s];
439 	int ret;
440 
441 	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
442 	confree(s);
443 	return (ret);
444 }
445 
446 static void
447 congreet(int s)
448 {
449 	int n = 0, remote_major = 0, remote_minor = 0;
450 	char buf[256], *cp;
451 	char remote_version[sizeof buf];
452 	size_t bufsiz;
453 	con *c = &fdcon[s];
454 
455 	/* send client banner */
456 	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
457 	    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2);
458 	if (n < 0 || (size_t)n >= sizeof(buf)) {
459 		error("snprintf: buffer too small");
460 		confree(s);
461 		return;
462 	}
463 	if (atomicio(vwrite, s, buf, n) != (size_t)n) {
464 		error("write (%s): %s", c->c_name, strerror(errno));
465 		confree(s);
466 		return;
467 	}
468 
469 	/*
470 	 * Read the server banner as per RFC4253 section 4.2.  The "SSH-"
471 	 * protocol identification string may be preceded by an arbitrarily
472 	 * large banner which we must read and ignore.  Loop while reading
473 	 * newline-terminated lines until we have one starting with "SSH-".
474 	 * The ID string cannot be longer than 255 characters although the
475 	 * preceding banner lines may (in which case they'll be discarded
476 	 * in multiple iterations of the outer loop).
477 	 */
478 	for (;;) {
479 		memset(buf, '\0', sizeof(buf));
480 		bufsiz = sizeof(buf);
481 		cp = buf;
482 		while (bufsiz-- &&
483 		    (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
484 			if (*cp == '\r')
485 				*cp = '\n';
486 			cp++;
487 		}
488 		if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
489 			break;
490 	}
491 	if (n == 0) {
492 		switch (errno) {
493 		case EPIPE:
494 			error("%s: Connection closed by remote host", c->c_name);
495 			break;
496 		case ECONNREFUSED:
497 			break;
498 		default:
499 			error("read (%s): %s", c->c_name, strerror(errno));
500 			break;
501 		}
502 		conrecycle(s);
503 		return;
504 	}
505 	if (cp >= buf + sizeof(buf)) {
506 		error("%s: greeting exceeds allowable length", c->c_name);
507 		confree(s);
508 		return;
509 	}
510 	if (*cp != '\n' && *cp != '\r') {
511 		error("%s: bad greeting", c->c_name);
512 		confree(s);
513 		return;
514 	}
515 	*cp = '\0';
516 	if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL)
517 		fatal("ssh_packet_set_connection failed");
518 	ssh_packet_set_timeout(c->c_ssh, timeout, 1);
519 	ssh_set_app_data(c->c_ssh, c);	/* back link */
520 	c->c_ssh->compat = 0;
521 	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
522 	    &remote_major, &remote_minor, remote_version) == 3)
523 		compat_banner(c->c_ssh, remote_version);
524 	if (!ssh2_capable(remote_major, remote_minor)) {
525 		debug("%s doesn't support ssh2", c->c_name);
526 		confree(s);
527 		return;
528 	}
529 	if (!quiet) {
530 		fprintf(stdout, "%c %s:%d %s\n", print_sshfp ? ';' : '#',
531 		    c->c_name, ssh_port, chop(buf));
532 	}
533 	keygrab_ssh2(c);
534 	confree(s);
535 }
536 
537 static void
538 conread(int s)
539 {
540 	con *c = &fdcon[s];
541 
542 	if (c->c_status != CS_CON)
543 		fatal("conread: invalid status %d", c->c_status);
544 
545 	congreet(s);
546 }
547 
548 static void
549 conloop(void)
550 {
551 	struct timespec seltime, now;
552 	con *c;
553 	int i;
554 
555 	monotime_ts(&now);
556 	c = TAILQ_FIRST(&tq);
557 
558 	if (c && timespeccmp(&c->c_ts, &now, >))
559 		timespecsub(&c->c_ts, &now, &seltime);
560 	else
561 		timespecclear(&seltime);
562 
563 	while (ppoll(read_wait, maxfd, &seltime, NULL) == -1) {
564 		if (errno == EAGAIN || errno == EINTR)
565 			continue;
566 		error("poll error");
567 	}
568 
569 	for (i = 0; i < maxfd; i++) {
570 		if (read_wait[i].revents & (POLLHUP|POLLERR|POLLNVAL))
571 			confree(i);
572 		else if (read_wait[i].revents & (POLLIN|POLLHUP))
573 			conread(i);
574 	}
575 
576 	c = TAILQ_FIRST(&tq);
577 	while (c && timespeccmp(&c->c_ts, &now, <)) {
578 		int s = c->c_fd;
579 
580 		c = TAILQ_NEXT(c, c_link);
581 		conrecycle(s);
582 	}
583 }
584 
585 static void
586 do_one_host(char *host)
587 {
588 	char *name = strnnsep(&host, " \t\n");
589 	int j;
590 
591 	if (name == NULL)
592 		return;
593 	for (j = KT_MIN; j <= KT_MAX; j *= 2) {
594 		if (get_keytypes & j) {
595 			while (ncon >= MAXCON)
596 				conloop();
597 			conalloc(name, *host ? host : name, j);
598 		}
599 	}
600 }
601 
602 static void
603 do_host(char *host)
604 {
605 	char daddr[128];
606 	struct xaddr addr, end_addr;
607 	u_int masklen;
608 
609 	if (host == NULL)
610 		return;
611 	if (addr_pton_cidr(host, &addr, &masklen) != 0) {
612 		/* Assume argument is a hostname */
613 		do_one_host(host);
614 	} else {
615 		/* Argument is a CIDR range */
616 		debug("CIDR range %s", host);
617 		end_addr = addr;
618 		if (addr_host_to_all1s(&end_addr, masklen) != 0)
619 			goto badaddr;
620 		/*
621 		 * Note: we deliberately include the all-zero/ones addresses.
622 		 */
623 		for (;;) {
624 			if (addr_ntop(&addr, daddr, sizeof(daddr)) != 0) {
625  badaddr:
626 				error("Invalid address %s", host);
627 				return;
628 			}
629 			debug("CIDR expand: address %s", daddr);
630 			do_one_host(daddr);
631 			if (addr_cmp(&addr, &end_addr) == 0)
632 				break;
633 			addr_increment(&addr);
634 		};
635 	}
636 }
637 
638 void
639 sshfatal(const char *file, const char *func, int line, int showfunc,
640     LogLevel level, const char *suffix, const char *fmt, ...)
641 {
642 	va_list args;
643 
644 	va_start(args, fmt);
645 	sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
646 	va_end(args);
647 	cleanup_exit(255);
648 }
649 
650 __dead static void
651 usage(void)
652 {
653 	fprintf(stderr,
654 	    "usage: ssh-keyscan [-46cDHqv] [-f file] [-O option] [-p port] [-T timeout]\n"
655 	    "                   [-t type] [host | addrlist namelist]\n");
656 	exit(1);
657 }
658 
659 int
660 main(int argc, char **argv)
661 {
662 	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
663 	int opt, fopt_count = 0, j;
664 	char *tname, *cp, *line = NULL;
665 	size_t linesize = 0;
666 	FILE *fp;
667 
668 	extern int optind;
669 	extern char *optarg;
670 
671 	TAILQ_INIT(&tq);
672 
673 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
674 	sanitise_stdfd();
675 
676 	if (argc <= 1)
677 		usage();
678 
679 	while ((opt = getopt(argc, argv, "cDHqv46O:p:T:t:f:")) != -1) {
680 		switch (opt) {
681 		case 'H':
682 			hash_hosts = 1;
683 			break;
684 		case 'c':
685 			get_cert = 1;
686 			break;
687 		case 'D':
688 			print_sshfp = 1;
689 			break;
690 		case 'p':
691 			ssh_port = a2port(optarg);
692 			if (ssh_port <= 0) {
693 				fprintf(stderr, "Bad port '%s'\n", optarg);
694 				exit(1);
695 			}
696 			break;
697 		case 'T':
698 			timeout = convtime(optarg);
699 			if (timeout == -1 || timeout == 0) {
700 				fprintf(stderr, "Bad timeout '%s'\n", optarg);
701 				usage();
702 			}
703 			break;
704 		case 'v':
705 			if (!debug_flag) {
706 				debug_flag = 1;
707 				log_level = SYSLOG_LEVEL_DEBUG1;
708 			}
709 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
710 				log_level++;
711 			else
712 				fatal("Too high debugging level.");
713 			break;
714 		case 'q':
715 			quiet = 1;
716 			break;
717 		case 'f':
718 			if (strcmp(optarg, "-") == 0)
719 				optarg = NULL;
720 			argv[fopt_count++] = optarg;
721 			break;
722 		case 'O':
723 			/* Maybe other misc options in the future too */
724 			if (strncmp(optarg, "hashalg=", 8) != 0)
725 				fatal("Unsupported -O option");
726 			if ((hashalg = ssh_digest_alg_by_name(
727 			    optarg + 8)) == -1)
728 				fatal("Unsupported hash algorithm");
729 			break;
730 		case 't':
731 			get_keytypes = 0;
732 			tname = strtok(optarg, ",");
733 			while (tname) {
734 				int type = sshkey_type_from_shortname(tname);
735 
736 				switch (type) {
737 #ifdef WITH_DSA
738 				case KEY_DSA:
739 					get_keytypes |= KT_DSA;
740 					break;
741 #endif
742 				case KEY_ECDSA:
743 					get_keytypes |= KT_ECDSA;
744 					break;
745 				case KEY_RSA:
746 					get_keytypes |= KT_RSA;
747 					break;
748 				case KEY_ED25519:
749 					get_keytypes |= KT_ED25519;
750 					break;
751 				case KEY_XMSS:
752 					get_keytypes |= KT_XMSS;
753 					break;
754 				case KEY_ED25519_SK:
755 					get_keytypes |= KT_ED25519_SK;
756 					break;
757 				case KEY_ECDSA_SK:
758 					get_keytypes |= KT_ECDSA_SK;
759 					break;
760 				case KEY_UNSPEC:
761 				default:
762 					fatal("Unknown key type \"%s\"", tname);
763 				}
764 				tname = strtok(NULL, ",");
765 			}
766 			break;
767 		case '4':
768 			IPv4or6 = AF_INET;
769 			break;
770 		case '6':
771 			IPv4or6 = AF_INET6;
772 			break;
773 		default:
774 			usage();
775 		}
776 	}
777 	if (optind == argc && !fopt_count)
778 		usage();
779 
780 	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
781 
782 	maxfd = fdlim_get(1);
783 	if (maxfd < 0)
784 		fatal("%s: fdlim_get: bad value", __progname);
785 	if (maxfd > MAXMAXFD)
786 		maxfd = MAXMAXFD;
787 	if (MAXCON <= 0)
788 		fatal("%s: not enough file descriptors", __progname);
789 	if (maxfd > fdlim_get(0))
790 		fdlim_set(maxfd);
791 	fdcon = xcalloc(maxfd, sizeof(con));
792 	read_wait = xcalloc(maxfd, sizeof(struct pollfd));
793 	for (j = 0; j < maxfd; j++)
794 		read_wait[j].fd = -1;
795 
796 	for (j = 0; j < fopt_count; j++) {
797 		if (argv[j] == NULL)
798 			fp = stdin;
799 		else if ((fp = fopen(argv[j], "r")) == NULL)
800 			fatal("%s: %s: %s", __progname,
801 			    fp == stdin ? "<stdin>" : argv[j], strerror(errno));
802 
803 		while (getline(&line, &linesize, fp) != -1) {
804 			/* Chomp off trailing whitespace and comments */
805 			if ((cp = strchr(line, '#')) == NULL)
806 				cp = line + strlen(line) - 1;
807 			while (cp >= line) {
808 				if (*cp == ' ' || *cp == '\t' ||
809 				    *cp == '\n' || *cp == '#')
810 					*cp-- = '\0';
811 				else
812 					break;
813 			}
814 
815 			/* Skip empty lines */
816 			if (*line == '\0')
817 				continue;
818 
819 			do_host(line);
820 		}
821 
822 		if (ferror(fp))
823 			fatal("%s: %s: %s", __progname,
824 			    fp == stdin ? "<stdin>" : argv[j], strerror(errno));
825 
826 		if (fp != stdin)
827 			fclose(fp);
828 	}
829 	free(line);
830 
831 	while (optind < argc)
832 		do_host(argv[optind++]);
833 
834 	while (ncon > 0)
835 		conloop();
836 
837 	return found_one ? 0 : 1;
838 }
839