1 /* $OpenBSD: ssh-keyscan.c,v 1.105 2016/02/15 09:47:49 dtucker 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;
64 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519;
66 int hash_hosts = 0; /* Hash hostname on output */
70 /* The number of seconds after which to give up on a TCP connection */
74 #define MAXCON (maxfd - 10)
76 extern char *__progname;
78 size_t read_wait_nfdset;
81 struct ssh *active_state = NULL; /* XXX needed for linking */
84 * Keep a connection structure for each file descriptor. The state
85 * associated with file descriptor n is held in fdcon[n].
87 typedef struct Connection {
88 u_char c_status; /* State of connection on this file desc. */
89 #define CS_UNUSED 0 /* File descriptor unused */
90 #define CS_CON 1 /* Waiting to connect/read greeting */
91 #define CS_SIZE 2 /* Waiting to read initial packet size */
92 #define CS_KEYS 3 /* Waiting to read public key packet */
93 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
94 int c_plen; /* Packet length field for ssh packet */
95 int c_len; /* Total bytes which must be read. */
96 int c_off; /* Length of data read so far. */
97 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
98 sig_atomic_t c_done; /* SSH2 done */
99 char *c_namebase; /* Address to free for c_name and c_namelist */
100 char *c_name; /* Hostname of connection for errors */
101 char *c_namelist; /* Pointer to other possible addresses */
102 char *c_output_name; /* Hostname of connection for output */
103 char *c_data; /* Data read from this fd */
104 struct ssh *c_ssh; /* SSH-connection */
105 struct timeval c_tv; /* Time at which connection gets aborted */
106 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
109 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
112 static void keyprint(con *c, struct sshkey *key);
117 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
120 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
122 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
125 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
134 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
140 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
141 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
144 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
146 #elif defined (HAVE_SETDTABLESIZE)
153 * This is an strsep function that returns a null field for adjacent
154 * separators. This is the same as the 4.4BSD strsep, but different from the
155 * one in the GNU libc.
158 xstrsep(char **str, const char *delim)
166 e = s + strcspn(s, delim);
176 * Get the next non-null token (like GNU strsep). Strsep() will return a
177 * null token for two adjacent separators, so we may have to loop.
180 strnnsep(char **stringp, char *delim)
185 tok = xstrsep(stringp, delim);
186 } while (tok && *tok == '\0');
191 static struct sshkey *
194 static struct sshkey *rsa;
195 static struct sshbuf *msg;
200 if ((rsa = sshkey_new(KEY_RSA1)) == NULL) {
201 error("%s: sshkey_new failed", __func__);
204 if ((msg = sshbuf_new()) == NULL)
205 fatal("%s: sshbuf_new failed", __func__);
207 if ((r = sshbuf_put(msg, c->c_data, c->c_plen)) != 0 ||
208 (r = sshbuf_consume(msg, 8 - (c->c_plen & 7))) != 0 || /* padding */
209 (r = sshbuf_get_u8(msg, &type)) != 0)
211 if (type != (int) SSH_SMSG_PUBLIC_KEY) {
212 error("%s: invalid packet type", c->c_name);
216 if ((r = sshbuf_consume(msg, 8)) != 0 || /* cookie */
218 (r = sshbuf_get_u32(msg, NULL)) != 0 ||
219 (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
220 (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
222 (r = sshbuf_get_u32(msg, NULL)) != 0 ||
223 (r = sshbuf_get_bignum1(msg, rsa->rsa->e)) != 0 ||
224 (r = sshbuf_get_bignum1(msg, rsa->rsa->n)) != 0) {
226 error("%s: buffer error: %s", __func__, ssh_err(r));
238 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh)
242 if ((c = ssh_get_app_data(ssh)) != NULL)
243 keyprint(c, hostkey);
244 /* always abort key exchange */
249 ssh2_capable(int remote_major, int remote_minor)
251 switch (remote_major) {
253 if (remote_minor == 99)
267 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
271 switch (c->c_keytype) {
273 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
274 "ssh-dss-cert-v01@openssh.com" : "ssh-dss";
277 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
278 "ssh-rsa-cert-v01@openssh.com" : "ssh-rsa";
281 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
282 "ssh-ed25519-cert-v01@openssh.com" : "ssh-ed25519";
285 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
286 "ecdsa-sha2-nistp256-cert-v01@openssh.com,"
287 "ecdsa-sha2-nistp384-cert-v01@openssh.com,"
288 "ecdsa-sha2-nistp521-cert-v01@openssh.com" :
289 "ecdsa-sha2-nistp256,"
290 "ecdsa-sha2-nistp384,"
291 "ecdsa-sha2-nistp521";
294 fatal("unknown key type %d", c->c_keytype);
297 if ((r = kex_setup(c->c_ssh, myproposal)) != 0) {
299 fprintf(stderr, "kex_setup: %s\n", ssh_err(r));
303 c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
304 c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
305 c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
306 c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
307 # ifdef OPENSSL_HAS_ECC
308 c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
311 c->c_ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
312 ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
314 * do the key-exchange until an error occurs or until
315 * the key_print_wrapper() callback sets c_done.
317 ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done, c->c_ssh);
321 keyprint_one(char *host, struct sshkey *key)
325 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
326 fatal("host_hash failed");
328 hostport = put_host_port(host, ssh_port);
330 fprintf(stdout, "%s ", hostport);
331 sshkey_write(key, stdout);
337 keyprint(con *c, struct sshkey *key)
339 char *hosts = c->c_output_name ? c->c_output_name : c->c_name;
344 if (get_cert || (!hash_hosts && ssh_port == SSH_DEFAULT_PORT)) {
345 keyprint_one(hosts, key);
348 ohosts = hosts = xstrdup(hosts);
349 while ((host = strsep(&hosts, ",")) != NULL)
350 keyprint_one(host, key);
355 tcpconnect(char *host)
357 struct addrinfo hints, *ai, *aitop;
358 char strport[NI_MAXSERV];
361 snprintf(strport, sizeof strport, "%d", ssh_port);
362 memset(&hints, 0, sizeof(hints));
363 hints.ai_family = IPv4or6;
364 hints.ai_socktype = SOCK_STREAM;
365 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
366 error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
369 for (ai = aitop; ai; ai = ai->ai_next) {
370 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
372 error("socket: %s", strerror(errno));
375 if (set_nonblock(s) == -1)
376 fatal("%s: set_nonblock(%d)", __func__, s);
377 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
378 errno != EINPROGRESS)
379 error("connect (`%s'): %s", host, strerror(errno));
390 conalloc(char *iname, char *oname, int keytype)
392 char *namebase, *name, *namelist;
395 namebase = namelist = xstrdup(iname);
398 name = xstrsep(&namelist, ",");
403 } while ((s = tcpconnect(name)) < 0);
406 fatal("conalloc: fdno %d too high", s);
407 if (fdcon[s].c_status)
408 fatal("conalloc: attempt to reuse fdno %d", s);
410 debug3("%s: oname %s kt %d", __func__, oname, keytype);
412 fdcon[s].c_status = CS_CON;
413 fdcon[s].c_namebase = namebase;
414 fdcon[s].c_name = name;
415 fdcon[s].c_namelist = namelist;
416 fdcon[s].c_output_name = xstrdup(oname);
417 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
420 fdcon[s].c_keytype = keytype;
421 gettimeofday(&fdcon[s].c_tv, NULL);
422 fdcon[s].c_tv.tv_sec += timeout;
423 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
424 FD_SET(s, read_wait);
432 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
433 fatal("confree: attempt to free bad fdno %d", s);
435 free(fdcon[s].c_namebase);
436 free(fdcon[s].c_output_name);
437 if (fdcon[s].c_status == CS_KEYS)
438 free(fdcon[s].c_data);
439 fdcon[s].c_status = CS_UNUSED;
440 fdcon[s].c_keytype = 0;
441 if (fdcon[s].c_ssh) {
442 ssh_packet_close(fdcon[s].c_ssh);
443 free(fdcon[s].c_ssh);
444 fdcon[s].c_ssh = NULL;
446 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
447 FD_CLR(s, read_wait);
454 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
455 gettimeofday(&fdcon[s].c_tv, NULL);
456 fdcon[s].c_tv.tv_sec += timeout;
457 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
466 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
474 int n = 0, remote_major = 0, remote_minor = 0;
476 char remote_version[sizeof buf];
481 memset(buf, '\0', sizeof(buf));
482 bufsiz = sizeof(buf);
485 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
490 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
496 error("%s: Connection closed by remote host", c->c_name);
501 error("read (%s): %s", c->c_name, strerror(errno));
507 if (*cp != '\n' && *cp != '\r') {
508 error("%s: bad greeting", c->c_name);
513 if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL)
514 fatal("ssh_packet_set_connection failed");
515 ssh_packet_set_timeout(c->c_ssh, timeout, 1);
516 ssh_set_app_data(c->c_ssh, c); /* back link */
517 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
518 &remote_major, &remote_minor, remote_version) == 3)
519 c->c_ssh->compat = compat_datafellows(remote_version);
521 c->c_ssh->compat = 0;
522 if (c->c_keytype != KT_RSA1) {
523 if (!ssh2_capable(remote_major, remote_minor)) {
524 debug("%s doesn't support ssh2", c->c_name);
528 } else if (remote_major != 1) {
529 debug("%s doesn't support ssh1", c->c_name);
533 fprintf(stderr, "# %s:%d %s\n", c->c_name, ssh_port, chop(buf));
534 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
535 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
536 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
537 if (n < 0 || (size_t)n >= sizeof(buf)) {
538 error("snprintf: buffer too small");
542 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
543 error("write (%s): %s", c->c_name, strerror(errno));
547 if (c->c_keytype != KT_RSA1) {
552 c->c_status = CS_SIZE;
562 if (c->c_status == CS_CON) {
566 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
568 error("read (%s): %s", c->c_name, strerror(errno));
574 if (c->c_off == c->c_len)
575 switch (c->c_status) {
577 c->c_plen = htonl(c->c_plen);
578 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
580 c->c_data = xmalloc(c->c_len);
581 c->c_status = CS_KEYS;
585 keyprint(c, keygrab_ssh1(c));
590 fatal("conread: invalid status %d", c->c_status);
600 struct timeval seltime, now;
605 gettimeofday(&now, NULL);
606 c = TAILQ_FIRST(&tq);
608 if (c && (c->c_tv.tv_sec > now.tv_sec ||
609 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
611 seltime.tv_sec -= now.tv_sec;
612 seltime.tv_usec -= now.tv_usec;
613 if (seltime.tv_usec < 0) {
614 seltime.tv_usec += 1000000;
618 timerclear(&seltime);
620 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
621 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
622 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
623 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
625 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
626 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
629 for (i = 0; i < maxfd; i++) {
630 if (FD_ISSET(i, e)) {
631 error("%s: exception!", fdcon[i].c_name);
633 } else if (FD_ISSET(i, r))
639 c = TAILQ_FIRST(&tq);
640 while (c && (c->c_tv.tv_sec < now.tv_sec ||
641 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
644 c = TAILQ_NEXT(c, c_link);
652 char *name = strnnsep(&host, " \t\n");
657 for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
658 if (get_keytypes & j) {
659 while (ncon >= MAXCON)
661 conalloc(name, *host ? host : name, j);
667 fatal(const char *fmt,...)
672 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
681 "usage: %s [-46cHv] [-f file] [-p port] [-T timeout] [-t type]\n"
682 "\t\t [host | addrlist namelist] ...\n",
688 main(int argc, char **argv)
690 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
691 int opt, fopt_count = 0, j;
692 char *tname, *cp, line[NI_MAXHOST];
699 ssh_malloc_init(); /* must be called before any mallocs */
700 __progname = ssh_get_progname(argv[0]);
704 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
710 while ((opt = getopt(argc, argv, "cHv46p:T:t:f:")) != -1) {
719 ssh_port = a2port(optarg);
721 fprintf(stderr, "Bad port '%s'\n", optarg);
726 timeout = convtime(optarg);
727 if (timeout == -1 || timeout == 0) {
728 fprintf(stderr, "Bad timeout '%s'\n", optarg);
735 log_level = SYSLOG_LEVEL_DEBUG1;
737 else if (log_level < SYSLOG_LEVEL_DEBUG3)
740 fatal("Too high debugging level.");
743 if (strcmp(optarg, "-") == 0)
745 argv[fopt_count++] = optarg;
749 tname = strtok(optarg, ",");
751 int type = sshkey_type_from_name(tname);
754 get_keytypes |= KT_RSA1;
757 get_keytypes |= KT_DSA;
760 get_keytypes |= KT_ECDSA;
763 get_keytypes |= KT_RSA;
766 get_keytypes |= KT_ED25519;
769 fatal("unknown key type %s", tname);
771 tname = strtok(NULL, ",");
785 if (optind == argc && !fopt_count)
788 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
790 maxfd = fdlim_get(1);
792 fatal("%s: fdlim_get: bad value", __progname);
793 if (maxfd > MAXMAXFD)
796 fatal("%s: not enough file descriptors", __progname);
797 if (maxfd > fdlim_get(0))
799 fdcon = xcalloc(maxfd, sizeof(con));
801 read_wait_nfdset = howmany(maxfd, NFDBITS);
802 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
804 for (j = 0; j < fopt_count; j++) {
807 else if ((fp = fopen(argv[j], "r")) == NULL)
808 fatal("%s: %s: %s", __progname, argv[j],
812 while (read_keyfile_line(fp,
813 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
815 /* Chomp off trailing whitespace and comments */
816 if ((cp = strchr(line, '#')) == NULL)
817 cp = line + strlen(line) - 1;
819 if (*cp == ' ' || *cp == '\t' ||
820 *cp == '\n' || *cp == '#')
826 /* Skip empty lines */
834 fatal("%s: %s: %s", __progname, argv[j],
840 while (optind < argc)
841 do_host(argv[optind++]);