1 /* $OpenBSD: ssh-keyscan.c,v 1.101 2015/04/10 00:08:55 djm Exp $ */
3 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
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.
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>
19 #include <netinet/in.h>
20 #include <arpa/inet.h>
22 #include <openssl/bn.h>
41 #include "myproposal.h"
51 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
52 Default value is AF_UNSPEC means both IPv4 and IPv6. */
53 int IPv4or6 = AF_UNSPEC;
55 int ssh_port = SSH_DEFAULT_PORT;
63 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519;
65 int hash_hosts = 0; /* Hash hostname on output */
69 /* The number of seconds after which to give up on a TCP connection */
73 #define MAXCON (maxfd - 10)
75 extern char *__progname;
77 size_t read_wait_nfdset;
80 struct ssh *active_state = NULL; /* XXX needed for linking */
83 * Keep a connection structure for each file descriptor. The state
84 * associated with file descriptor n is held in fdcon[n].
86 typedef struct Connection {
87 u_char c_status; /* State of connection on this file desc. */
88 #define CS_UNUSED 0 /* File descriptor unused */
89 #define CS_CON 1 /* Waiting to connect/read greeting */
90 #define CS_SIZE 2 /* Waiting to read initial packet size */
91 #define CS_KEYS 3 /* Waiting to read public key packet */
92 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
93 int c_plen; /* Packet length field for ssh packet */
94 int c_len; /* Total bytes which must be read. */
95 int c_off; /* Length of data read so far. */
96 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
97 sig_atomic_t c_done; /* SSH2 done */
98 char *c_namebase; /* Address to free for c_name and c_namelist */
99 char *c_name; /* Hostname of connection for errors */
100 char *c_namelist; /* Pointer to other possible addresses */
101 char *c_output_name; /* Hostname of connection for output */
102 char *c_data; /* Data read from this fd */
103 struct ssh *c_ssh; /* SSH-connection */
104 struct timeval c_tv; /* Time at which connection gets aborted */
105 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
108 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
111 static void keyprint(con *c, struct sshkey *key);
116 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
119 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
121 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
124 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
133 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
139 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
140 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
143 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
145 #elif defined (HAVE_SETDTABLESIZE)
152 * This is an strsep function that returns a null field for adjacent
153 * separators. This is the same as the 4.4BSD strsep, but different from the
154 * one in the GNU libc.
157 xstrsep(char **str, const char *delim)
165 e = s + strcspn(s, delim);
175 * Get the next non-null token (like GNU strsep). Strsep() will return a
176 * null token for two adjacent separators, so we may have to loop.
179 strnnsep(char **stringp, char *delim)
184 tok = xstrsep(stringp, delim);
185 } while (tok && *tok == '\0');
190 static struct sshkey *
193 static struct sshkey *rsa;
194 static struct sshbuf *msg;
199 if ((rsa = sshkey_new(KEY_RSA1)) == NULL) {
200 error("%s: sshkey_new failed", __func__);
203 if ((msg = sshbuf_new()) == NULL)
204 fatal("%s: sshbuf_new failed", __func__);
206 if ((r = sshbuf_put(msg, c->c_data, c->c_plen)) != 0 ||
207 (r = sshbuf_consume(msg, 8 - (c->c_plen & 7))) != 0 || /* padding */
208 (r = sshbuf_get_u8(msg, &type)) != 0)
210 if (type != (int) SSH_SMSG_PUBLIC_KEY) {
211 error("%s: invalid packet type", c->c_name);
215 if ((r = sshbuf_consume(msg, 8)) != 0 || /* cookie */
217 (r = sshbuf_get_u32(msg, NULL)) != 0 ||
218 (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
219 (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
221 (r = sshbuf_get_u32(msg, NULL)) != 0 ||
222 (r = sshbuf_get_bignum1(msg, rsa->rsa->e)) != 0 ||
223 (r = sshbuf_get_bignum1(msg, rsa->rsa->n)) != 0) {
225 error("%s: buffer error: %s", __func__, ssh_err(r));
237 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh)
241 if ((c = ssh_get_app_data(ssh)) != NULL)
242 keyprint(c, hostkey);
243 /* always abort key exchange */
248 ssh2_capable(int remote_major, int remote_minor)
250 switch (remote_major) {
252 if (remote_minor == 99)
266 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
270 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
271 c->c_keytype == KT_DSA ? "ssh-dss" :
272 (c->c_keytype == KT_RSA ? "ssh-rsa" :
273 (c->c_keytype == KT_ED25519 ? "ssh-ed25519" :
274 "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521"));
275 if ((r = kex_setup(c->c_ssh, myproposal)) != 0) {
277 fprintf(stderr, "kex_setup: %s\n", ssh_err(r));
281 c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
282 c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
283 c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
284 c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
285 # ifdef OPENSSL_HAS_ECC
286 c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
289 c->c_ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
290 ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
292 * do the key-exchange until an error occurs or until
293 * the key_print_wrapper() callback sets c_done.
295 ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done, c->c_ssh);
299 keyprint(con *c, struct sshkey *key)
301 char *host = c->c_output_name ? c->c_output_name : c->c_name;
302 char *hostport = NULL;
306 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
307 fatal("host_hash failed");
309 hostport = put_host_port(host, ssh_port);
310 fprintf(stdout, "%s ", hostport);
311 sshkey_write(key, stdout);
317 tcpconnect(char *host)
319 struct addrinfo hints, *ai, *aitop;
320 char strport[NI_MAXSERV];
323 snprintf(strport, sizeof strport, "%d", ssh_port);
324 memset(&hints, 0, sizeof(hints));
325 hints.ai_family = IPv4or6;
326 hints.ai_socktype = SOCK_STREAM;
327 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
328 error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
331 for (ai = aitop; ai; ai = ai->ai_next) {
332 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
334 error("socket: %s", strerror(errno));
337 if (set_nonblock(s) == -1)
338 fatal("%s: set_nonblock(%d)", __func__, s);
339 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
340 errno != EINPROGRESS)
341 error("connect (`%s'): %s", host, strerror(errno));
352 conalloc(char *iname, char *oname, int keytype)
354 char *namebase, *name, *namelist;
357 namebase = namelist = xstrdup(iname);
360 name = xstrsep(&namelist, ",");
365 } while ((s = tcpconnect(name)) < 0);
368 fatal("conalloc: fdno %d too high", s);
369 if (fdcon[s].c_status)
370 fatal("conalloc: attempt to reuse fdno %d", s);
373 fdcon[s].c_status = CS_CON;
374 fdcon[s].c_namebase = namebase;
375 fdcon[s].c_name = name;
376 fdcon[s].c_namelist = namelist;
377 fdcon[s].c_output_name = xstrdup(oname);
378 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
381 fdcon[s].c_keytype = keytype;
382 gettimeofday(&fdcon[s].c_tv, NULL);
383 fdcon[s].c_tv.tv_sec += timeout;
384 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
385 FD_SET(s, read_wait);
393 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
394 fatal("confree: attempt to free bad fdno %d", s);
396 free(fdcon[s].c_namebase);
397 free(fdcon[s].c_output_name);
398 if (fdcon[s].c_status == CS_KEYS)
399 free(fdcon[s].c_data);
400 fdcon[s].c_status = CS_UNUSED;
401 fdcon[s].c_keytype = 0;
402 if (fdcon[s].c_ssh) {
403 ssh_packet_close(fdcon[s].c_ssh);
404 free(fdcon[s].c_ssh);
405 fdcon[s].c_ssh = NULL;
407 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
408 FD_CLR(s, read_wait);
415 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
416 gettimeofday(&fdcon[s].c_tv, NULL);
417 fdcon[s].c_tv.tv_sec += timeout;
418 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
427 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
435 int n = 0, remote_major = 0, remote_minor = 0;
437 char remote_version[sizeof buf];
442 memset(buf, '\0', sizeof(buf));
443 bufsiz = sizeof(buf);
446 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
451 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
457 error("%s: Connection closed by remote host", c->c_name);
462 error("read (%s): %s", c->c_name, strerror(errno));
468 if (*cp != '\n' && *cp != '\r') {
469 error("%s: bad greeting", c->c_name);
474 if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL)
475 fatal("ssh_packet_set_connection failed");
476 ssh_packet_set_timeout(c->c_ssh, timeout, 1);
477 ssh_set_app_data(c->c_ssh, c); /* back link */
478 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
479 &remote_major, &remote_minor, remote_version) == 3)
480 c->c_ssh->compat = compat_datafellows(remote_version);
482 c->c_ssh->compat = 0;
483 if (c->c_keytype != KT_RSA1) {
484 if (!ssh2_capable(remote_major, remote_minor)) {
485 debug("%s doesn't support ssh2", c->c_name);
489 } else if (remote_major != 1) {
490 debug("%s doesn't support ssh1", c->c_name);
494 fprintf(stderr, "# %s:%d %s\n", c->c_name, ssh_port, chop(buf));
495 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
496 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
497 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
498 if (n < 0 || (size_t)n >= sizeof(buf)) {
499 error("snprintf: buffer too small");
503 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
504 error("write (%s): %s", c->c_name, strerror(errno));
508 if (c->c_keytype != KT_RSA1) {
513 c->c_status = CS_SIZE;
523 if (c->c_status == CS_CON) {
527 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
529 error("read (%s): %s", c->c_name, strerror(errno));
535 if (c->c_off == c->c_len)
536 switch (c->c_status) {
538 c->c_plen = htonl(c->c_plen);
539 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
541 c->c_data = xmalloc(c->c_len);
542 c->c_status = CS_KEYS;
546 keyprint(c, keygrab_ssh1(c));
551 fatal("conread: invalid status %d", c->c_status);
561 struct timeval seltime, now;
566 gettimeofday(&now, NULL);
567 c = TAILQ_FIRST(&tq);
569 if (c && (c->c_tv.tv_sec > now.tv_sec ||
570 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
572 seltime.tv_sec -= now.tv_sec;
573 seltime.tv_usec -= now.tv_usec;
574 if (seltime.tv_usec < 0) {
575 seltime.tv_usec += 1000000;
579 timerclear(&seltime);
581 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
582 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
583 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
584 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
586 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
587 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
590 for (i = 0; i < maxfd; i++) {
591 if (FD_ISSET(i, e)) {
592 error("%s: exception!", fdcon[i].c_name);
594 } else if (FD_ISSET(i, r))
600 c = TAILQ_FIRST(&tq);
601 while (c && (c->c_tv.tv_sec < now.tv_sec ||
602 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
605 c = TAILQ_NEXT(c, c_link);
613 char *name = strnnsep(&host, " \t\n");
618 for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
619 if (get_keytypes & j) {
620 while (ncon >= MAXCON)
622 conalloc(name, *host ? host : name, j);
628 fatal(const char *fmt,...)
633 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
642 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
643 "\t\t [host | addrlist namelist] ...\n",
649 main(int argc, char **argv)
651 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
652 int opt, fopt_count = 0, j;
653 char *tname, *cp, line[NI_MAXHOST];
660 __progname = ssh_get_progname(argv[0]);
664 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
670 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
676 ssh_port = a2port(optarg);
678 fprintf(stderr, "Bad port '%s'\n", optarg);
683 timeout = convtime(optarg);
684 if (timeout == -1 || timeout == 0) {
685 fprintf(stderr, "Bad timeout '%s'\n", optarg);
692 log_level = SYSLOG_LEVEL_DEBUG1;
694 else if (log_level < SYSLOG_LEVEL_DEBUG3)
697 fatal("Too high debugging level.");
700 if (strcmp(optarg, "-") == 0)
702 argv[fopt_count++] = optarg;
706 tname = strtok(optarg, ",");
708 int type = sshkey_type_from_name(tname);
711 get_keytypes |= KT_RSA1;
714 get_keytypes |= KT_DSA;
717 get_keytypes |= KT_ECDSA;
720 get_keytypes |= KT_RSA;
723 get_keytypes |= KT_ED25519;
726 fatal("unknown key type %s", tname);
728 tname = strtok(NULL, ",");
742 if (optind == argc && !fopt_count)
745 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
747 maxfd = fdlim_get(1);
749 fatal("%s: fdlim_get: bad value", __progname);
750 if (maxfd > MAXMAXFD)
753 fatal("%s: not enough file descriptors", __progname);
754 if (maxfd > fdlim_get(0))
756 fdcon = xcalloc(maxfd, sizeof(con));
758 read_wait_nfdset = howmany(maxfd, NFDBITS);
759 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
761 for (j = 0; j < fopt_count; j++) {
764 else if ((fp = fopen(argv[j], "r")) == NULL)
765 fatal("%s: %s: %s", __progname, argv[j],
769 while (read_keyfile_line(fp,
770 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
772 /* Chomp off trailing whitespace and comments */
773 if ((cp = strchr(line, '#')) == NULL)
774 cp = line + strlen(line) - 1;
776 if (*cp == ' ' || *cp == '\t' ||
777 *cp == '\n' || *cp == '#')
783 /* Skip empty lines */
791 fatal("%s: %s: %s", __progname, argv[j],
797 while (optind < argc)
798 do_host(argv[optind++]);