1 /* $OpenBSD: ssh-keyscan.c,v 1.64 2006/03/25 13:17:02 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 "openbsd-compat/sys-queue.h"
13 #include <sys/resource.h>
15 #include <openssl/bn.h>
24 #include "myproposal.h"
34 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
35 Default value is AF_UNSPEC means both IPv4 and IPv6. */
36 int IPv4or6 = AF_UNSPEC;
38 int ssh_port = SSH_DEFAULT_PORT;
44 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
46 int hash_hosts = 0; /* Hash hostname on output */
50 /* The number of seconds after which to give up on a TCP connection */
54 #define MAXCON (maxfd - 10)
56 extern char *__progname;
58 size_t read_wait_nfdset;
60 int nonfatal_fatal = 0;
65 * Keep a connection structure for each file descriptor. The state
66 * associated with file descriptor n is held in fdcon[n].
68 typedef struct Connection {
69 u_char c_status; /* State of connection on this file desc. */
70 #define CS_UNUSED 0 /* File descriptor unused */
71 #define CS_CON 1 /* Waiting to connect/read greeting */
72 #define CS_SIZE 2 /* Waiting to read initial packet size */
73 #define CS_KEYS 3 /* Waiting to read public key packet */
74 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
75 int c_plen; /* Packet length field for ssh packet */
76 int c_len; /* Total bytes which must be read. */
77 int c_off; /* Length of data read so far. */
78 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
79 char *c_namebase; /* Address to free for c_name and c_namelist */
80 char *c_name; /* Hostname of connection for errors */
81 char *c_namelist; /* Pointer to other possible addresses */
82 char *c_output_name; /* Hostname of connection for output */
83 char *c_data; /* Data read from this fd */
84 Kex *c_kex; /* The key-exchange struct for ssh2 */
85 struct timeval c_tv; /* Time at which connection gets aborted */
86 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
89 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
93 * This is just a wrapper around fgets() to make it usable.
96 /* Stress-test. Increase this later. */
97 #define LINEBUF_SIZE 16
103 const char *filename;
105 void (*errfun) (const char *,...);
109 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
113 if (!(lb = malloc(sizeof(*lb)))) {
115 (*errfun) ("linebuf (%s): malloc failed\n",
116 filename ? filename : "(stdin)");
120 lb->filename = filename;
121 if (!(lb->stream = fopen(filename, "r"))) {
124 (*errfun) ("%s: %s\n", filename, strerror(errno));
128 lb->filename = "(stdin)";
132 if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
134 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
144 Linebuf_free(Linebuf * lb)
153 Linebuf_restart(Linebuf * lb)
155 clearerr(lb->stream);
161 Linebuf_lineno(Linebuf * lb)
168 Linebuf_getline(Linebuf * lb)
176 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
177 if (ferror(lb->stream) && lb->errfun)
178 (*lb->errfun)("%s: %s\n", lb->filename,
184 /* Return it or an error if it fits */
185 if (n > 0 && lb->buf[n - 1] == '\n') {
186 lb->buf[n - 1] = '\0';
189 if (n != lb->size - 1) {
191 (*lb->errfun)("%s: skipping incomplete last line\n",
195 /* Double the buffer if we need more space */
197 if ((p = realloc(lb->buf, lb->size)) == NULL) {
200 (*lb->errfun)("linebuf (%s): realloc failed\n",
211 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
214 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
216 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
219 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
228 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
234 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
235 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
238 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
240 #elif defined (HAVE_SETDTABLESIZE)
247 * This is an strsep function that returns a null field for adjacent
248 * separators. This is the same as the 4.4BSD strsep, but different from the
249 * one in the GNU libc.
252 xstrsep(char **str, const char *delim)
260 e = s + strcspn(s, delim);
270 * Get the next non-null token (like GNU strsep). Strsep() will return a
271 * null token for two adjacent separators, so we may have to loop.
274 strnnsep(char **stringp, char *delim)
279 tok = xstrsep(stringp, delim);
280 } while (tok && *tok == '\0');
292 rsa = key_new(KEY_RSA1);
294 buffer_append(&msg, c->c_data, c->c_plen);
295 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
296 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
297 error("%s: invalid packet type", c->c_name);
301 buffer_consume(&msg, 8); /* cookie */
304 (void) buffer_get_int(&msg);
305 buffer_get_bignum(&msg, rsa->rsa->e);
306 buffer_get_bignum(&msg, rsa->rsa->n);
309 (void) buffer_get_int(&msg);
310 buffer_get_bignum(&msg, rsa->rsa->e);
311 buffer_get_bignum(&msg, rsa->rsa->n);
319 hostjump(Key *hostkey)
321 kexjmp_key = hostkey;
326 ssh2_capable(int remote_major, int remote_minor)
328 switch (remote_major) {
330 if (remote_minor == 99)
346 packet_set_connection(c->c_fd, c->c_fd);
348 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
349 "ssh-dss": "ssh-rsa";
350 c->c_kex = kex_setup(myproposal);
351 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
352 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
353 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
354 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
355 c->c_kex->verify_host_key = hostjump;
357 if (!(j = setjmp(kexjmp))) {
359 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
360 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
368 return j < 0? NULL : kexjmp_key;
372 keyprint(con *c, Key *key)
374 char *host = c->c_output_name ? c->c_output_name : c->c_name;
378 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
379 fatal("host_hash failed");
381 fprintf(stdout, "%s ", host);
382 key_write(key, stdout);
387 tcpconnect(char *host)
389 struct addrinfo hints, *ai, *aitop;
390 char strport[NI_MAXSERV];
393 snprintf(strport, sizeof strport, "%d", ssh_port);
394 memset(&hints, 0, sizeof(hints));
395 hints.ai_family = IPv4or6;
396 hints.ai_socktype = SOCK_STREAM;
397 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
398 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
399 for (ai = aitop; ai; ai = ai->ai_next) {
400 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
402 error("socket: %s", strerror(errno));
405 if (set_nonblock(s) == -1)
406 fatal("%s: set_nonblock(%d)", __func__, s);
407 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
408 errno != EINPROGRESS)
409 error("connect (`%s'): %s", host, strerror(errno));
420 conalloc(char *iname, char *oname, int keytype)
422 char *namebase, *name, *namelist;
425 namebase = namelist = xstrdup(iname);
428 name = xstrsep(&namelist, ",");
433 } while ((s = tcpconnect(name)) < 0);
436 fatal("conalloc: fdno %d too high", s);
437 if (fdcon[s].c_status)
438 fatal("conalloc: attempt to reuse fdno %d", s);
441 fdcon[s].c_status = CS_CON;
442 fdcon[s].c_namebase = namebase;
443 fdcon[s].c_name = name;
444 fdcon[s].c_namelist = namelist;
445 fdcon[s].c_output_name = xstrdup(oname);
446 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
449 fdcon[s].c_keytype = keytype;
450 gettimeofday(&fdcon[s].c_tv, NULL);
451 fdcon[s].c_tv.tv_sec += timeout;
452 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
453 FD_SET(s, read_wait);
461 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
462 fatal("confree: attempt to free bad fdno %d", s);
464 xfree(fdcon[s].c_namebase);
465 xfree(fdcon[s].c_output_name);
466 if (fdcon[s].c_status == CS_KEYS)
467 xfree(fdcon[s].c_data);
468 fdcon[s].c_status = CS_UNUSED;
469 fdcon[s].c_keytype = 0;
470 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
471 FD_CLR(s, read_wait);
478 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
479 gettimeofday(&fdcon[s].c_tv, NULL);
480 fdcon[s].c_tv.tv_sec += timeout;
481 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
490 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
498 int n = 0, remote_major = 0, remote_minor = 0;
500 char remote_version[sizeof buf];
505 memset(buf, '\0', sizeof(buf));
506 bufsiz = sizeof(buf);
509 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
514 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
520 error("%s: Connection closed by remote host", c->c_name);
525 error("read (%s): %s", c->c_name, strerror(errno));
531 if (*cp != '\n' && *cp != '\r') {
532 error("%s: bad greeting", c->c_name);
537 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
538 &remote_major, &remote_minor, remote_version) == 3)
539 compat_datafellows(remote_version);
542 if (c->c_keytype != KT_RSA1) {
543 if (!ssh2_capable(remote_major, remote_minor)) {
544 debug("%s doesn't support ssh2", c->c_name);
548 } else if (remote_major != 1) {
549 debug("%s doesn't support ssh1", c->c_name);
553 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
554 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
555 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
556 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
557 if (n < 0 || (size_t)n >= sizeof(buf)) {
558 error("snprintf: buffer too small");
562 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
563 error("write (%s): %s", c->c_name, strerror(errno));
567 if (c->c_keytype != KT_RSA1) {
568 keyprint(c, keygrab_ssh2(c));
572 c->c_status = CS_SIZE;
582 if (c->c_status == CS_CON) {
586 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
588 error("read (%s): %s", c->c_name, strerror(errno));
594 if (c->c_off == c->c_len)
595 switch (c->c_status) {
597 c->c_plen = htonl(c->c_plen);
598 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
600 c->c_data = xmalloc(c->c_len);
601 c->c_status = CS_KEYS;
604 keyprint(c, keygrab_ssh1(c));
608 fatal("conread: invalid status %d", c->c_status);
618 struct timeval seltime, now;
623 gettimeofday(&now, NULL);
624 c = TAILQ_FIRST(&tq);
626 if (c && (c->c_tv.tv_sec > now.tv_sec ||
627 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
629 seltime.tv_sec -= now.tv_sec;
630 seltime.tv_usec -= now.tv_usec;
631 if (seltime.tv_usec < 0) {
632 seltime.tv_usec += 1000000;
636 seltime.tv_sec = seltime.tv_usec = 0;
638 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
639 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
640 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
641 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
643 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
644 (errno == EAGAIN || errno == EINTR))
647 for (i = 0; i < maxfd; i++) {
648 if (FD_ISSET(i, e)) {
649 error("%s: exception!", fdcon[i].c_name);
651 } else if (FD_ISSET(i, r))
657 c = TAILQ_FIRST(&tq);
658 while (c && (c->c_tv.tv_sec < now.tv_sec ||
659 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
662 c = TAILQ_NEXT(c, c_link);
670 char *name = strnnsep(&host, " \t\n");
675 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
676 if (get_keytypes & j) {
677 while (ncon >= MAXCON)
679 conalloc(name, *host ? host : name, j);
685 fatal(const char *fmt,...)
690 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
701 fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
702 "\t\t [host | addrlist namelist] [...]\n",
708 main(int argc, char **argv)
710 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
711 int opt, fopt_count = 0;
717 __progname = ssh_get_progname(argv[0]);
722 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
728 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
734 ssh_port = a2port(optarg);
736 fprintf(stderr, "Bad port '%s'\n", optarg);
741 timeout = convtime(optarg);
742 if (timeout == -1 || timeout == 0) {
743 fprintf(stderr, "Bad timeout '%s'\n", optarg);
750 log_level = SYSLOG_LEVEL_DEBUG1;
752 else if (log_level < SYSLOG_LEVEL_DEBUG3)
755 fatal("Too high debugging level.");
758 if (strcmp(optarg, "-") == 0)
760 argv[fopt_count++] = optarg;
764 tname = strtok(optarg, ",");
766 int type = key_type_from_name(tname);
769 get_keytypes |= KT_RSA1;
772 get_keytypes |= KT_DSA;
775 get_keytypes |= KT_RSA;
778 fatal("unknown key type %s", tname);
780 tname = strtok(NULL, ",");
794 if (optind == argc && !fopt_count)
797 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
799 maxfd = fdlim_get(1);
801 fatal("%s: fdlim_get: bad value", __progname);
802 if (maxfd > MAXMAXFD)
805 fatal("%s: not enough file descriptors", __progname);
806 if (maxfd > fdlim_get(0))
808 fdcon = xcalloc(maxfd, sizeof(con));
810 read_wait_nfdset = howmany(maxfd, NFDBITS);
811 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
818 for (j = 0; j < fopt_count; j++) {
819 lb = Linebuf_alloc(argv[j], error);
822 while ((line = Linebuf_getline(lb)) != NULL)
828 while (optind < argc)
829 do_host(argv[optind++]);