xref: /freebsd/crypto/openssh/ssh-keyscan.c (revision 644b4646c7acab87dc20d4e5dd53d2d9da152989)
1 /* $OpenBSD: ssh-keyscan.c,v 1.167 2025/08/29 03:50:38 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 #include <sys/time.h>
16 
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
19 
20 #ifdef WITH_OPENSSL
21 #include <openssl/bn.h>
22 #endif
23 
24 #include <errno.h>
25 #include <limits.h>
26 #include <netdb.h>
27 #include <stdarg.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <poll.h>
31 #include <signal.h>
32 #include <string.h>
33 #include <unistd.h>
34 
35 #include "xmalloc.h"
36 #include "ssh.h"
37 #include "sshbuf.h"
38 #include "sshkey.h"
39 #include "cipher.h"
40 #include "digest.h"
41 #include "kex.h"
42 #include "compat.h"
43 #include "myproposal.h"
44 #include "packet.h"
45 #include "dispatch.h"
46 #include "log.h"
47 #include "atomicio.h"
48 #include "misc.h"
49 #include "hostfile.h"
50 #include "ssherr.h"
51 #include "ssh_api.h"
52 #include "dns.h"
53 #include "addr.h"
54 
55 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
56    Default value is AF_UNSPEC means both IPv4 and IPv6. */
57 int IPv4or6 = AF_UNSPEC;
58 
59 int ssh_port = SSH_DEFAULT_PORT;
60 
61 #define KT_RSA		(1)
62 #define KT_ECDSA	(1<<1)
63 #define KT_ED25519	(1<<2)
64 #define KT_ECDSA_SK	(1<<4)
65 #define KT_ED25519_SK	(1<<5)
66 
67 #define KT_MIN		KT_RSA
68 #define KT_MAX		KT_ED25519_SK
69 
70 int get_cert = 0;
71 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519|KT_ECDSA_SK|KT_ED25519_SK;
72 
73 int hash_hosts = 0;		/* Hash hostname on output */
74 
75 int print_sshfp = 0;		/* Print SSHFP records instead of known_hosts */
76 
77 int found_one = 0;		/* Successfully found a key */
78 
79 int hashalg = -1;		/* Hash for SSHFP records or -1 for all */
80 
81 int quiet = 0;			/* Don't print key comment lines */
82 
83 #define MAXMAXFD 256
84 
85 /* The number of seconds after which to give up on a TCP connection */
86 int timeout = 5;
87 
88 int maxfd;
89 #define MAXCON (maxfd - 10)
90 
91 extern char *__progname;
92 struct pollfd *read_wait;
93 int ncon;
94 
95 /*
96  * Keep a connection structure for each file descriptor.  The state
97  * associated with file descriptor n is held in fdcon[n].
98  */
99 typedef struct Connection {
100 	u_char c_status;	/* State of connection on this file desc. */
101 #define CS_UNUSED 0		/* File descriptor unused */
102 #define CS_CON 1		/* Waiting to connect/read greeting */
103 	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
104 	int c_keytype;		/* Only one of KT_* */
105 	sig_atomic_t c_done;	/* SSH2 done */
106 	char *c_namebase;	/* Address to free for c_name and c_namelist */
107 	char *c_name;		/* Hostname of connection for errors */
108 	char *c_namelist;	/* Pointer to other possible addresses */
109 	char *c_output_name;	/* Hostname of connection for output */
110 	struct ssh *c_ssh;	/* SSH-connection */
111 	struct timespec c_ts;	/* Time at which connection gets aborted */
112 	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
113 } con;
114 
115 TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
116 con *fdcon;
117 
118 static void keyprint(con *c, struct sshkey *key);
119 
120 static int
fdlim_get(int hard)121 fdlim_get(int hard)
122 {
123 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
124 	struct rlimit rlfd;
125 	rlim_t lim;
126 
127 	if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1)
128 		return -1;
129 	lim = hard ? rlfd.rlim_max : rlfd.rlim_cur;
130 	if (lim <= 0)
131 		return -1;
132 	if (lim == RLIM_INFINITY)
133 		lim = SSH_SYSFDMAX;
134 	if (lim >= INT_MAX)
135 		lim = INT_MAX;
136 	return lim;
137 #else
138 	return (SSH_SYSFDMAX <= 0) ? -1 :
139 	    ((SSH_SYSFDMAX >= INT_MAX) ? INT_MAX : SSH_SYSFDMAX);
140 #endif
141 }
142 
143 static int
fdlim_set(int lim)144 fdlim_set(int lim)
145 {
146 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
147 	struct rlimit rlfd;
148 #endif
149 
150 	if (lim <= 0)
151 		return (-1);
152 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
153 	if (getrlimit(RLIMIT_NOFILE, &rlfd) == -1)
154 		return (-1);
155 	rlfd.rlim_cur = lim;
156 	if (setrlimit(RLIMIT_NOFILE, &rlfd) == -1)
157 		return (-1);
158 #elif defined (HAVE_SETDTABLESIZE)
159 	setdtablesize(lim);
160 #endif
161 	return (0);
162 }
163 
164 /*
165  * This is an strsep function that returns a null field for adjacent
166  * separators.  This is the same as the 4.4BSD strsep, but different from the
167  * one in the GNU libc.
168  */
169 static char *
xstrsep(char ** str,const char * delim)170 xstrsep(char **str, const char *delim)
171 {
172 	char *s, *e;
173 
174 	if (!**str)
175 		return (NULL);
176 
177 	s = *str;
178 	e = s + strcspn(s, delim);
179 
180 	if (*e != '\0')
181 		*e++ = '\0';
182 	*str = e;
183 
184 	return (s);
185 }
186 
187 /*
188  * Get the next non-null token (like GNU strsep).  Strsep() will return a
189  * null token for two adjacent separators, so we may have to loop.
190  */
191 static char *
strnnsep(char ** stringp,char * delim)192 strnnsep(char **stringp, char *delim)
193 {
194 	char *tok;
195 
196 	do {
197 		tok = xstrsep(stringp, delim);
198 	} while (tok && *tok == '\0');
199 	return (tok);
200 }
201 
202 
203 static int
key_print_wrapper(struct sshkey * hostkey,struct ssh * ssh)204 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh)
205 {
206 	con *c;
207 
208 	if ((c = ssh_get_app_data(ssh)) != NULL)
209 		keyprint(c, hostkey);
210 	/* always abort key exchange */
211 	return -1;
212 }
213 
214 static int
ssh2_capable(int remote_major,int remote_minor)215 ssh2_capable(int remote_major, int remote_minor)
216 {
217 	switch (remote_major) {
218 	case 1:
219 		if (remote_minor == 99)
220 			return 1;
221 		break;
222 	case 2:
223 		return 1;
224 	default:
225 		break;
226 	}
227 	return 0;
228 }
229 
230 static void
keygrab_ssh2(con * c)231 keygrab_ssh2(con *c)
232 {
233 	char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
234 	int r;
235 
236 	switch (c->c_keytype) {
237 	case KT_RSA:
238 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
239 		    "rsa-sha2-512-cert-v01@openssh.com,"
240 		    "rsa-sha2-256-cert-v01@openssh.com,"
241 		    "ssh-rsa-cert-v01@openssh.com" :
242 		    "rsa-sha2-512,"
243 		    "rsa-sha2-256,"
244 		    "ssh-rsa";
245 		break;
246 	case KT_ED25519:
247 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
248 		    "ssh-ed25519-cert-v01@openssh.com" : "ssh-ed25519";
249 		break;
250 	case KT_ECDSA:
251 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
252 		    "ecdsa-sha2-nistp256-cert-v01@openssh.com,"
253 		    "ecdsa-sha2-nistp384-cert-v01@openssh.com,"
254 		    "ecdsa-sha2-nistp521-cert-v01@openssh.com" :
255 		    "ecdsa-sha2-nistp256,"
256 		    "ecdsa-sha2-nistp384,"
257 		    "ecdsa-sha2-nistp521";
258 		break;
259 	case KT_ECDSA_SK:
260 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
261 		    "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com" :
262 		    "sk-ecdsa-sha2-nistp256@openssh.com";
263 		break;
264 	case KT_ED25519_SK:
265 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
266 		    "sk-ssh-ed25519-cert-v01@openssh.com" :
267 		    "sk-ssh-ed25519@openssh.com";
268 		break;
269 	default:
270 		fatal("unknown key type %d", c->c_keytype);
271 		break;
272 	}
273 	if ((r = kex_setup(c->c_ssh, myproposal)) != 0) {
274 		free(c->c_ssh);
275 		fprintf(stderr, "kex_setup: %s\n", ssh_err(r));
276 		exit(1);
277 	}
278 #ifdef WITH_OPENSSL
279 	c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
280 	c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
281 	c->c_ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
282 	c->c_ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
283 	c->c_ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
284 	c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
285 	c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
286 # ifdef OPENSSL_HAS_ECC
287 	c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
288 # endif
289 #endif
290 	c->c_ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
291 	c->c_ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
292 	c->c_ssh->kex->kex[KEX_KEM_MLKEM768X25519_SHA256] = kex_gen_client;
293 	ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
294 	/*
295 	 * do the key-exchange until an error occurs or until
296 	 * the key_print_wrapper() callback sets c_done.
297 	 */
298 	ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done);
299 }
300 
301 static void
keyprint_one(const char * host,struct sshkey * key)302 keyprint_one(const char *host, struct sshkey *key)
303 {
304 	char *hostport = NULL, *hashed = NULL;
305 	const char *known_host;
306 	int r = 0;
307 
308 	found_one = 1;
309 
310 	if (print_sshfp) {
311 		export_dns_rr(host, key, stdout, 0, hashalg);
312 		return;
313 	}
314 
315 	hostport = put_host_port(host, ssh_port);
316 	lowercase(hostport);
317 	if (hash_hosts && (hashed = host_hash(hostport, NULL, 0)) == NULL)
318 		fatal("host_hash failed");
319 	known_host = hash_hosts ? hashed : hostport;
320 	if (!get_cert)
321 		r = fprintf(stdout, "%s ", known_host);
322 	if (r >= 0 && sshkey_write(key, stdout) == 0)
323 		(void)fputs("\n", stdout);
324 	free(hashed);
325 	free(hostport);
326 }
327 
328 static void
keyprint(con * c,struct sshkey * key)329 keyprint(con *c, struct sshkey *key)
330 {
331 	char *hosts = c->c_output_name ? c->c_output_name : c->c_name;
332 	char *host, *ohosts;
333 
334 	if (key == NULL)
335 		return;
336 	if (get_cert || (!hash_hosts && ssh_port == SSH_DEFAULT_PORT)) {
337 		keyprint_one(hosts, key);
338 		return;
339 	}
340 	ohosts = hosts = xstrdup(hosts);
341 	while ((host = strsep(&hosts, ",")) != NULL)
342 		keyprint_one(host, key);
343 	free(ohosts);
344 }
345 
346 static int
tcpconnect(char * host)347 tcpconnect(char *host)
348 {
349 	struct addrinfo hints, *ai, *aitop;
350 	char strport[NI_MAXSERV];
351 	int gaierr, s = -1;
352 
353 	snprintf(strport, sizeof strport, "%d", ssh_port);
354 	memset(&hints, 0, sizeof(hints));
355 	hints.ai_family = IPv4or6;
356 	hints.ai_socktype = SOCK_STREAM;
357 	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
358 		error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
359 		return -1;
360 	}
361 	for (ai = aitop; ai; ai = ai->ai_next) {
362 		s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
363 		if (s == -1) {
364 			error("socket: %s", strerror(errno));
365 			continue;
366 		}
367 		if (set_nonblock(s) == -1)
368 			fatal_f("set_nonblock(%d)", s);
369 		if (connect(s, ai->ai_addr, ai->ai_addrlen) == -1 &&
370 		    errno != EINPROGRESS)
371 			error("connect (`%s'): %s", host, strerror(errno));
372 		else
373 			break;
374 		close(s);
375 		s = -1;
376 	}
377 	freeaddrinfo(aitop);
378 	return s;
379 }
380 
381 static int
conalloc(const char * iname,const char * oname,int keytype)382 conalloc(const char *iname, const char *oname, int keytype)
383 {
384 	char *namebase, *name, *namelist;
385 	int s;
386 
387 	namebase = namelist = xstrdup(iname);
388 
389 	do {
390 		name = xstrsep(&namelist, ",");
391 		if (!name) {
392 			free(namebase);
393 			return (-1);
394 		}
395 	} while ((s = tcpconnect(name)) < 0);
396 
397 	if (s >= maxfd)
398 		fatal("conalloc: fdno %d too high", s);
399 	if (fdcon[s].c_status)
400 		fatal("conalloc: attempt to reuse fdno %d", s);
401 
402 	debug3_f("oname %s kt %d", oname, keytype);
403 	fdcon[s].c_fd = s;
404 	fdcon[s].c_status = CS_CON;
405 	fdcon[s].c_namebase = namebase;
406 	fdcon[s].c_name = name;
407 	fdcon[s].c_namelist = namelist;
408 	fdcon[s].c_output_name = xstrdup(oname);
409 	fdcon[s].c_keytype = keytype;
410 	monotime_ts(&fdcon[s].c_ts);
411 	fdcon[s].c_ts.tv_sec += timeout;
412 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
413 	read_wait[s].fd = s;
414 	read_wait[s].events = POLLIN;
415 	ncon++;
416 	return (s);
417 }
418 
419 static void
confree(int s)420 confree(int s)
421 {
422 	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
423 		fatal("confree: attempt to free bad fdno %d", s);
424 	free(fdcon[s].c_namebase);
425 	free(fdcon[s].c_output_name);
426 	fdcon[s].c_status = CS_UNUSED;
427 	fdcon[s].c_keytype = 0;
428 	if (fdcon[s].c_ssh) {
429 		ssh_packet_close(fdcon[s].c_ssh);
430 		free(fdcon[s].c_ssh);
431 		fdcon[s].c_ssh = NULL;
432 	} else
433 		close(s);
434 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
435 	read_wait[s].fd = -1;
436 	read_wait[s].events = 0;
437 	ncon--;
438 }
439 
440 static int
conrecycle(int s)441 conrecycle(int s)
442 {
443 	con *c = &fdcon[s];
444 	int ret;
445 
446 	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
447 	confree(s);
448 	return (ret);
449 }
450 
451 static void
congreet(int s)452 congreet(int s)
453 {
454 	int n = 0, remote_major = 0, remote_minor = 0;
455 	char buf[256], *cp;
456 	char remote_version[sizeof buf];
457 	size_t bufsiz;
458 	con *c = &fdcon[s];
459 
460 	/* send client banner */
461 	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
462 	    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2);
463 	if (n < 0 || (size_t)n >= sizeof(buf)) {
464 		error("snprintf: buffer too small");
465 		confree(s);
466 		return;
467 	}
468 	if (atomicio(vwrite, s, buf, n) != (size_t)n) {
469 		error("write (%s): %s", c->c_name, strerror(errno));
470 		confree(s);
471 		return;
472 	}
473 
474 	/*
475 	 * Read the server banner as per RFC4253 section 4.2.  The "SSH-"
476 	 * protocol identification string may be preceded by an arbitrarily
477 	 * large banner which we must read and ignore.  Loop while reading
478 	 * newline-terminated lines until we have one starting with "SSH-".
479 	 * The ID string cannot be longer than 255 characters although the
480 	 * preceding banner lines may (in which case they'll be discarded
481 	 * in multiple iterations of the outer loop).
482 	 */
483 	for (;;) {
484 		memset(buf, '\0', sizeof(buf));
485 		bufsiz = sizeof(buf);
486 		cp = buf;
487 		while (bufsiz-- &&
488 		    (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
489 			if (*cp == '\r')
490 				*cp = '\n';
491 			cp++;
492 		}
493 		if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
494 			break;
495 	}
496 	if (n == 0) {
497 		switch (errno) {
498 		case EPIPE:
499 			error("%s: Connection closed by remote host", c->c_name);
500 			break;
501 		case ECONNREFUSED:
502 			break;
503 		default:
504 			error("read (%s): %s", c->c_name, strerror(errno));
505 			break;
506 		}
507 		conrecycle(s);
508 		return;
509 	}
510 	if (cp >= buf + sizeof(buf)) {
511 		error("%s: greeting exceeds allowable length", c->c_name);
512 		confree(s);
513 		return;
514 	}
515 	if (*cp != '\n' && *cp != '\r') {
516 		error("%s: bad greeting", c->c_name);
517 		confree(s);
518 		return;
519 	}
520 	*cp = '\0';
521 	if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL)
522 		fatal("ssh_packet_set_connection failed");
523 	ssh_packet_set_timeout(c->c_ssh, timeout, 1);
524 	ssh_set_app_data(c->c_ssh, c);	/* back link */
525 	c->c_ssh->compat = 0;
526 	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
527 	    &remote_major, &remote_minor, remote_version) == 3)
528 		compat_banner(c->c_ssh, remote_version);
529 	if (!ssh2_capable(remote_major, remote_minor)) {
530 		debug("%s doesn't support ssh2", c->c_name);
531 		confree(s);
532 		return;
533 	}
534 	if (!quiet) {
535 		fprintf(stdout, "%c %s:%d %s\n", print_sshfp ? ';' : '#',
536 		    c->c_name, ssh_port, chop(buf));
537 	}
538 	keygrab_ssh2(c);
539 	confree(s);
540 }
541 
542 static void
conread(int s)543 conread(int s)
544 {
545 	con *c = &fdcon[s];
546 
547 	if (c->c_status != CS_CON)
548 		fatal("conread: invalid status %d", c->c_status);
549 
550 	congreet(s);
551 }
552 
553 static void
conloop(void)554 conloop(void)
555 {
556 	struct timespec seltime, now;
557 	con *c;
558 	int i;
559 
560 	monotime_ts(&now);
561 	c = TAILQ_FIRST(&tq);
562 
563 	if (c && timespeccmp(&c->c_ts, &now, >))
564 		timespecsub(&c->c_ts, &now, &seltime);
565 	else
566 		timespecclear(&seltime);
567 
568 	while (ppoll(read_wait, maxfd, &seltime, NULL) == -1) {
569 		if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)
570 			continue;
571 		error("poll error");
572 	}
573 
574 	for (i = 0; i < maxfd; i++) {
575 		if (read_wait[i].revents & (POLLHUP|POLLERR|POLLNVAL))
576 			confree(i);
577 		else if (read_wait[i].revents & (POLLIN))
578 			conread(i);
579 	}
580 
581 	c = TAILQ_FIRST(&tq);
582 	while (c && timespeccmp(&c->c_ts, &now, <)) {
583 		int s = c->c_fd;
584 
585 		c = TAILQ_NEXT(c, c_link);
586 		conrecycle(s);
587 	}
588 }
589 
590 static void
do_one_host(char * host)591 do_one_host(char *host)
592 {
593 	char *name = strnnsep(&host, " \t\n");
594 	int j;
595 
596 	if (name == NULL)
597 		return;
598 	for (j = KT_MIN; j <= KT_MAX; j *= 2) {
599 		if (get_keytypes & j) {
600 			while (ncon >= MAXCON)
601 				conloop();
602 			conalloc(name, *host ? host : name, j);
603 		}
604 	}
605 }
606 
607 static void
do_host(char * host)608 do_host(char *host)
609 {
610 	char daddr[128];
611 	struct xaddr addr, end_addr;
612 	u_int masklen;
613 
614 	if (host == NULL)
615 		return;
616 	if (addr_pton_cidr(host, &addr, &masklen) != 0) {
617 		/* Assume argument is a hostname */
618 		do_one_host(host);
619 	} else {
620 		/* Argument is a CIDR range */
621 		debug("CIDR range %s", host);
622 		end_addr = addr;
623 		if (addr_host_to_all1s(&end_addr, masklen) != 0)
624 			goto badaddr;
625 		/*
626 		 * Note: we deliberately include the all-zero/ones addresses.
627 		 */
628 		for (;;) {
629 			if (addr_ntop(&addr, daddr, sizeof(daddr)) != 0) {
630  badaddr:
631 				error("Invalid address %s", host);
632 				return;
633 			}
634 			debug("CIDR expand: address %s", daddr);
635 			do_one_host(daddr);
636 			if (addr_cmp(&addr, &end_addr) == 0)
637 				break;
638 			addr_increment(&addr);
639 		}
640 	}
641 }
642 
643 static void
usage(void)644 usage(void)
645 {
646 	fprintf(stderr,
647 	    "usage: ssh-keyscan [-46cDHqv] [-f file] [-O option] [-p port] [-T timeout]\n"
648 	    "                   [-t type] [host | addrlist namelist]\n");
649 	exit(1);
650 }
651 
652 int
main(int argc,char ** argv)653 main(int argc, char **argv)
654 {
655 	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
656 	int opt, fopt_count = 0, j;
657 	char *tname, *cp, *line = NULL;
658 	size_t linesize = 0;
659 	FILE *fp;
660 
661 	extern int optind;
662 	extern char *optarg;
663 
664 	__progname = ssh_get_progname(argv[0]);
665 	seed_rng();
666 	TAILQ_INIT(&tq);
667 
668 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
669 	sanitise_stdfd();
670 
671 	if (argc <= 1)
672 		usage();
673 
674 	while ((opt = getopt(argc, argv, "cDHqv46O:p:T:t:f:")) != -1) {
675 		switch (opt) {
676 		case 'H':
677 			hash_hosts = 1;
678 			break;
679 		case 'c':
680 			get_cert = 1;
681 			break;
682 		case 'D':
683 			print_sshfp = 1;
684 			break;
685 		case 'p':
686 			ssh_port = a2port(optarg);
687 			if (ssh_port <= 0) {
688 				fprintf(stderr, "Bad port '%s'\n", optarg);
689 				exit(1);
690 			}
691 			break;
692 		case 'T':
693 			timeout = convtime(optarg);
694 			if (timeout == -1 || timeout == 0) {
695 				fprintf(stderr, "Bad timeout '%s'\n", optarg);
696 				usage();
697 			}
698 			break;
699 		case 'v':
700 			if (!debug_flag) {
701 				debug_flag = 1;
702 				log_level = SYSLOG_LEVEL_DEBUG1;
703 			}
704 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
705 				log_level++;
706 			else
707 				fatal("Too high debugging level.");
708 			break;
709 		case 'q':
710 			quiet = 1;
711 			break;
712 		case 'f':
713 			if (strcmp(optarg, "-") == 0)
714 				optarg = NULL;
715 			argv[fopt_count++] = optarg;
716 			break;
717 		case 'O':
718 			/* Maybe other misc options in the future too */
719 			if (strncmp(optarg, "hashalg=", 8) != 0)
720 				fatal("Unsupported -O option");
721 			if ((hashalg = ssh_digest_alg_by_name(
722 			    optarg + 8)) == -1)
723 				fatal("Unsupported hash algorithm");
724 			break;
725 		case 't':
726 			get_keytypes = 0;
727 			tname = strtok(optarg, ",");
728 			while (tname) {
729 				int type = sshkey_type_from_shortname(tname);
730 
731 				switch (type) {
732 				case KEY_ECDSA:
733 					get_keytypes |= KT_ECDSA;
734 					break;
735 				case KEY_RSA:
736 					get_keytypes |= KT_RSA;
737 					break;
738 				case KEY_ED25519:
739 					get_keytypes |= KT_ED25519;
740 					break;
741 				case KEY_ED25519_SK:
742 					get_keytypes |= KT_ED25519_SK;
743 					break;
744 				case KEY_ECDSA_SK:
745 					get_keytypes |= KT_ECDSA_SK;
746 					break;
747 				case KEY_UNSPEC:
748 				default:
749 					fatal("Unknown key type \"%s\"", tname);
750 				}
751 				tname = strtok(NULL, ",");
752 			}
753 			break;
754 		case '4':
755 			IPv4or6 = AF_INET;
756 			break;
757 		case '6':
758 			IPv4or6 = AF_INET6;
759 			break;
760 		default:
761 			usage();
762 		}
763 	}
764 	if (optind == argc && !fopt_count)
765 		usage();
766 
767 	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
768 
769 	maxfd = fdlim_get(1);
770 	if (maxfd < 0)
771 		fatal("%s: fdlim_get: bad value", __progname);
772 	if (maxfd > MAXMAXFD)
773 		maxfd = MAXMAXFD;
774 	if (MAXCON <= 0)
775 		fatal("%s: not enough file descriptors", __progname);
776 	if (maxfd > fdlim_get(0))
777 		fdlim_set(maxfd);
778 	fdcon = xcalloc(maxfd, sizeof(con));
779 	read_wait = xcalloc(maxfd, sizeof(struct pollfd));
780 	for (j = 0; j < maxfd; j++)
781 		read_wait[j].fd = -1;
782 
783 	ssh_signal(SIGPIPE, SIG_IGN);
784 	for (j = 0; j < fopt_count; j++) {
785 		if (argv[j] == NULL)
786 			fp = stdin;
787 		else if ((fp = fopen(argv[j], "r")) == NULL)
788 			fatal("%s: %s: %s", __progname,
789 			    fp == stdin ? "<stdin>" : argv[j], strerror(errno));
790 
791 		while (getline(&line, &linesize, fp) != -1) {
792 			/* Chomp off trailing whitespace and comments */
793 			if ((cp = strchr(line, '#')) == NULL)
794 				cp = line + strlen(line) - 1;
795 			while (cp >= line) {
796 				if (*cp == ' ' || *cp == '\t' ||
797 				    *cp == '\n' || *cp == '#')
798 					*cp-- = '\0';
799 				else
800 					break;
801 			}
802 
803 			/* Skip empty lines */
804 			if (*line == '\0')
805 				continue;
806 
807 			do_host(line);
808 		}
809 
810 		if (ferror(fp))
811 			fatal("%s: %s: %s", __progname,
812 			    fp == stdin ? "<stdin>" : argv[j], strerror(errno));
813 
814 		if (fp != stdin)
815 			fclose(fp);
816 	}
817 	free(line);
818 
819 	while (optind < argc)
820 		do_host(argv[optind++]);
821 
822 	while (ncon > 0)
823 		conloop();
824 
825 	return found_one ? 0 : 1;
826 }
827