2 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
4 * Modification and redistribution in source and binary forms is
5 * permitted provided that due credit is given to the author and the
6 * OpenBSD project by leaving this copyright notice intact.
10 RCSID("$OpenBSD: ssh-keyscan.c,v 1.35 2002/03/04 18:30:23 stevesk Exp $");
12 #include "openbsd-compat/fake-queue.h"
14 #include <openssl/bn.h>
23 #include "myproposal.h"
32 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
33 Default value is AF_UNSPEC means both IPv4 and IPv6. */
35 int IPv4or6 = AF_INET;
37 int IPv4or6 = AF_UNSPEC;
40 int ssh_port = SSH_DEFAULT_PORT;
46 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
50 /* The number of seconds after which to give up on a TCP connection */
54 #define MAXCON (maxfd - 10)
56 #ifdef HAVE___PROGNAME
57 extern char *__progname;
62 size_t read_wait_size;
64 int nonfatal_fatal = 0;
69 * Keep a connection structure for each file descriptor. The state
70 * associated with file descriptor n is held in fdcon[n].
72 typedef struct Connection {
73 u_char c_status; /* State of connection on this file desc. */
74 #define CS_UNUSED 0 /* File descriptor unused */
75 #define CS_CON 1 /* Waiting to connect/read greeting */
76 #define CS_SIZE 2 /* Waiting to read initial packet size */
77 #define CS_KEYS 3 /* Waiting to read public key packet */
78 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
79 int c_plen; /* Packet length field for ssh packet */
80 int c_len; /* Total bytes which must be read. */
81 int c_off; /* Length of data read so far. */
82 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
83 char *c_namebase; /* Address to free for c_name and c_namelist */
84 char *c_name; /* Hostname of connection for errors */
85 char *c_namelist; /* Pointer to other possible addresses */
86 char *c_output_name; /* Hostname of connection for output */
87 char *c_data; /* Data read from this fd */
88 Kex *c_kex; /* The key-exchange struct for ssh2 */
89 struct timeval c_tv; /* Time at which connection gets aborted */
90 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
93 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
97 * This is just a wrapper around fgets() to make it usable.
100 /* Stress-test. Increase this later. */
101 #define LINEBUF_SIZE 16
107 const char *filename;
109 void (*errfun) (const char *,...);
113 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
117 if (!(lb = malloc(sizeof(*lb)))) {
119 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
123 lb->filename = filename;
124 if (!(lb->stream = fopen(filename, "r"))) {
127 (*errfun) ("%s: %s\n", filename, strerror(errno));
131 lb->filename = "(stdin)";
135 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
137 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
147 Linebuf_free(Linebuf * lb)
156 Linebuf_restart(Linebuf * lb)
158 clearerr(lb->stream);
164 Linebuf_lineno(Linebuf * lb)
171 Linebuf_getline(Linebuf * lb)
178 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
179 if (ferror(lb->stream) && lb->errfun)
180 (*lb->errfun) ("%s: %s\n", lb->filename,
186 /* Return it or an error if it fits */
187 if (n > 0 && lb->buf[n - 1] == '\n') {
188 lb->buf[n - 1] = '\0';
191 if (n != lb->size - 1) {
193 (*lb->errfun) ("%s: skipping incomplete last line\n",
197 /* Double the buffer if we need more space */
198 if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
200 (*lb->errfun) ("linebuf (%s): realloc failed\n",
210 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
213 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
215 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
218 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
219 #elif defined (HAVE_SYSCONF)
220 return sysconf (_SC_OPEN_MAX);
229 #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->verify_host_key = hostjump;
353 if (!(j = setjmp(kexjmp))) {
355 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
356 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
364 return j < 0? NULL : kexjmp_key;
368 keyprint(con *c, Key *key)
373 fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
374 key_write(key, stdout);
379 tcpconnect(char *host)
381 struct addrinfo hints, *ai, *aitop;
382 char strport[NI_MAXSERV];
385 snprintf(strport, sizeof strport, "%d", ssh_port);
386 memset(&hints, 0, sizeof(hints));
387 hints.ai_family = IPv4or6;
388 hints.ai_socktype = SOCK_STREAM;
389 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
390 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
391 for (ai = aitop; ai; ai = ai->ai_next) {
392 s = socket(ai->ai_family, SOCK_STREAM, 0);
394 error("socket: %s", strerror(errno));
397 if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
398 fatal("F_SETFL: %s", strerror(errno));
399 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
400 errno != EINPROGRESS)
401 error("connect (`%s'): %s", host, strerror(errno));
412 conalloc(char *iname, char *oname, int keytype)
415 char *namebase, *name, *namelist;
417 namebase = namelist = xstrdup(iname);
420 name = xstrsep(&namelist, ",");
425 } while ((s = tcpconnect(name)) < 0);
428 fatal("conalloc: fdno %d too high", s);
429 if (fdcon[s].c_status)
430 fatal("conalloc: attempt to reuse fdno %d", s);
433 fdcon[s].c_status = CS_CON;
434 fdcon[s].c_namebase = namebase;
435 fdcon[s].c_name = name;
436 fdcon[s].c_namelist = namelist;
437 fdcon[s].c_output_name = xstrdup(oname);
438 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
441 fdcon[s].c_keytype = keytype;
442 gettimeofday(&fdcon[s].c_tv, NULL);
443 fdcon[s].c_tv.tv_sec += timeout;
444 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
445 FD_SET(s, read_wait);
453 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
454 fatal("confree: attempt to free bad fdno %d", s);
456 xfree(fdcon[s].c_namebase);
457 xfree(fdcon[s].c_output_name);
458 if (fdcon[s].c_status == CS_KEYS)
459 xfree(fdcon[s].c_data);
460 fdcon[s].c_status = CS_UNUSED;
461 fdcon[s].c_keytype = 0;
462 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
463 FD_CLR(s, read_wait);
470 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
471 gettimeofday(&fdcon[s].c_tv, NULL);
472 fdcon[s].c_tv.tv_sec += timeout;
473 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
482 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
491 char remote_version[sizeof buf];
493 int remote_major, remote_minor, n = 0;
496 bufsiz = sizeof(buf);
498 while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
504 if (errno != ECONNREFUSED)
505 error("read (%s): %s", c->c_name, strerror(errno));
510 error("%s: Connection closed by remote host", c->c_name);
514 if (*cp != '\n' && *cp != '\r') {
515 error("%s: bad greeting", c->c_name);
520 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
521 &remote_major, &remote_minor, remote_version) == 3)
522 compat_datafellows(remote_version);
525 if (c->c_keytype != KT_RSA1) {
526 if (!ssh2_capable(remote_major, remote_minor)) {
527 debug("%s doesn't support ssh2", c->c_name);
531 } else if (remote_major != 1) {
532 debug("%s doesn't support ssh1", c->c_name);
536 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
537 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
538 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
539 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
540 if (atomicio(write, s, buf, n) != n) {
541 error("write (%s): %s", c->c_name, strerror(errno));
545 if (c->c_keytype != KT_RSA1) {
546 keyprint(c, keygrab_ssh2(c));
550 c->c_status = CS_SIZE;
560 if (c->c_status == CS_CON) {
564 n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
566 error("read (%s): %s", c->c_name, strerror(errno));
572 if (c->c_off == c->c_len)
573 switch (c->c_status) {
575 c->c_plen = htonl(c->c_plen);
576 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
578 c->c_data = xmalloc(c->c_len);
579 c->c_status = CS_KEYS;
582 keyprint(c, keygrab_ssh1(c));
587 fatal("conread: invalid status %d", c->c_status);
598 struct timeval seltime, now;
602 gettimeofday(&now, NULL);
605 if (c && (c->c_tv.tv_sec > now.tv_sec ||
606 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
608 seltime.tv_sec -= now.tv_sec;
609 seltime.tv_usec -= now.tv_usec;
610 if (seltime.tv_usec < 0) {
611 seltime.tv_usec += 1000000;
615 seltime.tv_sec = seltime.tv_usec = 0;
617 r = xmalloc(read_wait_size);
618 memcpy(r, read_wait, read_wait_size);
619 e = xmalloc(read_wait_size);
620 memcpy(e, read_wait, read_wait_size);
622 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
623 (errno == EAGAIN || errno == EINTR))
626 for (i = 0; i < maxfd; i++) {
627 if (FD_ISSET(i, e)) {
628 error("%s: exception!", fdcon[i].c_name);
630 } else if (FD_ISSET(i, r))
637 while (c && (c->c_tv.tv_sec < now.tv_sec ||
638 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
641 c = c->c_link.tqe_next;
649 char *name = strnnsep(&host, " \t\n");
654 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
655 if (get_keytypes & j) {
656 while (ncon >= MAXCON)
658 conalloc(name, *host ? host : name, j);
664 fatal(const char *fmt,...)
668 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
679 fprintf(stderr, "Usage: %s [options] host ...\n",
681 fprintf(stderr, "Options:\n");
682 fprintf(stderr, " -f file Read hosts or addresses from file.\n");
683 fprintf(stderr, " -p port Connect to the specified port.\n");
684 fprintf(stderr, " -t keytype Specify the host key type.\n");
685 fprintf(stderr, " -T timeout Set connection timeout.\n");
686 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
687 fprintf(stderr, " -4 Use IPv4 only.\n");
688 fprintf(stderr, " -6 Use IPv6 only.\n");
693 main(int argc, char **argv)
695 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
696 int opt, fopt_count = 0;
702 __progname = get_progname(argv[0]);
710 while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
713 ssh_port = a2port(optarg);
715 fprintf(stderr, "Bad port '%s'\n", optarg);
720 timeout = atoi(optarg);
727 log_level = SYSLOG_LEVEL_DEBUG1;
729 else if (log_level < SYSLOG_LEVEL_DEBUG3)
732 fatal("Too high debugging level.");
735 if (strcmp(optarg, "-") == 0)
737 argv[fopt_count++] = optarg;
741 tname = strtok(optarg, ",");
743 int type = key_type_from_name(tname);
746 get_keytypes |= KT_RSA1;
749 get_keytypes |= KT_DSA;
752 get_keytypes |= KT_RSA;
755 fatal("unknown key type %s", tname);
757 tname = strtok(NULL, ",");
771 if (optind == argc && !fopt_count)
774 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
776 maxfd = fdlim_get(1);
778 fatal("%s: fdlim_get: bad value", __progname);
779 if (maxfd > MAXMAXFD)
782 fatal("%s: not enough file descriptors", __progname);
783 if (maxfd > fdlim_get(0))
785 fdcon = xmalloc(maxfd * sizeof(con));
786 memset(fdcon, 0, maxfd * sizeof(con));
788 read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
789 read_wait = xmalloc(read_wait_size);
790 memset(read_wait, 0, read_wait_size);
797 for (j = 0; j < fopt_count; j++) {
798 lb = Linebuf_alloc(argv[j], error);
801 while ((line = Linebuf_getline(lb)) != NULL)
807 while (optind < argc)
808 do_host(argv[optind++]);