1 /* $OpenBSD: ssh-keyscan.c,v 1.155 2024/01/11 01:45:36 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
fdlim_get(int hard)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
fdlim_set(int lim)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 *
xstrsep(char ** str,const char * delim)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 *
strnnsep(char ** stringp,char * delim)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
key_print_wrapper(struct sshkey * hostkey,struct ssh * ssh)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
ssh2_capable(int remote_major,int remote_minor)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
keygrab_ssh2(con * c)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
keyprint_one(const char * host,struct sshkey * key)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
keyprint(con * c,struct sshkey * key)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
tcpconnect(char * host)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
conalloc(const char * iname,const char * oname,int keytype)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
confree(int s)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
contouch(int s)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
conrecycle(int s)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
congreet(int s)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 preceded 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 * preceding 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
conread(int s)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
conloop(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
do_one_host(char * host)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
do_host(char * host)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
sshfatal(const char * file,const char * func,int line,int showfunc,LogLevel level,const char * suffix,const char * fmt,...)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
usage(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
main(int argc,char ** argv)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 #ifdef WITH_DSA
795 case KEY_DSA:
796 get_keytypes |= KT_DSA;
797 break;
798 #endif
799 case KEY_ECDSA:
800 get_keytypes |= KT_ECDSA;
801 break;
802 case KEY_RSA:
803 get_keytypes |= KT_RSA;
804 break;
805 case KEY_ED25519:
806 get_keytypes |= KT_ED25519;
807 break;
808 case KEY_XMSS:
809 get_keytypes |= KT_XMSS;
810 break;
811 case KEY_ED25519_SK:
812 get_keytypes |= KT_ED25519_SK;
813 break;
814 case KEY_ECDSA_SK:
815 get_keytypes |= KT_ECDSA_SK;
816 break;
817 case KEY_UNSPEC:
818 default:
819 fatal("Unknown key type \"%s\"", tname);
820 }
821 tname = strtok(NULL, ",");
822 }
823 break;
824 case '4':
825 IPv4or6 = AF_INET;
826 break;
827 case '6':
828 IPv4or6 = AF_INET6;
829 break;
830 default:
831 usage();
832 }
833 }
834 if (optind == argc && !fopt_count)
835 usage();
836
837 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
838
839 maxfd = fdlim_get(1);
840 if (maxfd < 0)
841 fatal("%s: fdlim_get: bad value", __progname);
842 if (maxfd > MAXMAXFD)
843 maxfd = MAXMAXFD;
844 if (MAXCON <= 0)
845 fatal("%s: not enough file descriptors", __progname);
846 if (maxfd > fdlim_get(0))
847 fdlim_set(maxfd);
848 fdcon = xcalloc(maxfd, sizeof(con));
849 read_wait = xcalloc(maxfd, sizeof(struct pollfd));
850 for (j = 0; j < maxfd; j++)
851 read_wait[j].fd = -1;
852
853 for (j = 0; j < fopt_count; j++) {
854 if (argv[j] == NULL)
855 fp = stdin;
856 else if ((fp = fopen(argv[j], "r")) == NULL)
857 fatal("%s: %s: %s", __progname, argv[j], strerror(errno));
858
859 while (getline(&line, &linesize, fp) != -1) {
860 /* Chomp off trailing whitespace and comments */
861 if ((cp = strchr(line, '#')) == NULL)
862 cp = line + strlen(line) - 1;
863 while (cp >= line) {
864 if (*cp == ' ' || *cp == '\t' ||
865 *cp == '\n' || *cp == '#')
866 *cp-- = '\0';
867 else
868 break;
869 }
870
871 /* Skip empty lines */
872 if (*line == '\0')
873 continue;
874
875 do_host(line);
876 }
877
878 if (ferror(fp))
879 fatal("%s: %s: %s", __progname, argv[j], strerror(errno));
880
881 fclose(fp);
882 }
883 free(line);
884
885 while (optind < argc)
886 do_host(argv[optind++]);
887
888 while (ncon > 0)
889 conloop();
890
891 return found_one ? 0 : 1;
892 }
893