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 1.27 2001/08/05 23:29:58 markus Exp $");
12 #if defined(HAVE_SYS_QUEUE_H) && !defined(HAVE_BOGUS_SYS_QUEUE_H)
13 #include <sys/queue.h>
15 #include "openbsd-compat/fake-queue.h"
19 #include <openssl/bn.h>
28 #include "myproposal.h"
37 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
38 Default value is AF_UNSPEC means both IPv4 and IPv6. */
40 int IPv4or6 = AF_INET;
42 int IPv4or6 = AF_UNSPEC;
45 int ssh_port = SSH_DEFAULT_PORT;
51 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
55 /* The number of seconds after which to give up on a TCP connection */
59 #define MAXCON (maxfd - 10)
61 #ifdef HAVE___PROGNAME
62 extern char *__progname;
67 size_t read_wait_size;
69 int nonfatal_fatal = 0;
73 * Keep a connection structure for each file descriptor. The state
74 * associated with file descriptor n is held in fdcon[n].
76 typedef struct Connection {
77 u_char c_status; /* State of connection on this file desc. */
78 #define CS_UNUSED 0 /* File descriptor unused */
79 #define CS_CON 1 /* Waiting to connect/read greeting */
80 #define CS_SIZE 2 /* Waiting to read initial packet size */
81 #define CS_KEYS 3 /* Waiting to read public key packet */
82 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
83 int c_plen; /* Packet length field for ssh packet */
84 int c_len; /* Total bytes which must be read. */
85 int c_off; /* Length of data read so far. */
86 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
87 char *c_namebase; /* Address to free for c_name and c_namelist */
88 char *c_name; /* Hostname of connection for errors */
89 char *c_namelist; /* Pointer to other possible addresses */
90 char *c_output_name; /* Hostname of connection for output */
91 char *c_data; /* Data read from this fd */
92 Kex *c_kex; /* The key-exchange struct for ssh2 */
93 struct timeval c_tv; /* Time at which connection gets aborted */
94 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
97 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
101 * This is just a wrapper around fgets() to make it usable.
104 /* Stress-test. Increase this later. */
105 #define LINEBUF_SIZE 16
111 const char *filename;
113 void (*errfun) (const char *,...);
117 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
121 if (!(lb = malloc(sizeof(*lb)))) {
123 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
127 lb->filename = filename;
128 if (!(lb->stream = fopen(filename, "r"))) {
131 (*errfun) ("%s: %s\n", filename, strerror(errno));
135 lb->filename = "(stdin)";
139 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
141 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
151 Linebuf_free(Linebuf * lb)
160 Linebuf_restart(Linebuf * lb)
162 clearerr(lb->stream);
168 Linebuf_lineno(Linebuf * lb)
175 Linebuf_getline(Linebuf * lb)
182 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
183 if (ferror(lb->stream) && lb->errfun)
184 (*lb->errfun) ("%s: %s\n", lb->filename,
190 /* Return it or an error if it fits */
191 if (n > 0 && lb->buf[n - 1] == '\n') {
192 lb->buf[n - 1] = '\0';
195 if (n != lb->size - 1) {
197 (*lb->errfun) ("%s: skipping incomplete last line\n",
201 /* Double the buffer if we need more space */
202 if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
204 (*lb->errfun) ("linebuf (%s): realloc failed\n",
214 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
217 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
219 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
222 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
223 #elif defined (HAVE_SYSCONF)
224 return sysconf (_SC_OPEN_MAX);
233 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
238 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
239 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
242 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
244 #elif defined (HAVE_SETDTABLESIZE)
251 * This is an strsep function that returns a null field for adjacent
252 * separators. This is the same as the 4.4BSD strsep, but different from the
253 * one in the GNU libc.
256 xstrsep(char **str, const char *delim)
264 e = s + strcspn(s, delim);
274 * Get the next non-null token (like GNU strsep). Strsep() will return a
275 * null token for two adjacent separators, so we may have to loop.
278 strnnsep(char **stringp, char *delim)
283 tok = xstrsep(stringp, delim);
284 } while (tok && *tok == '\0');
296 rsa = key_new(KEY_RSA1);
298 buffer_append(&msg, c->c_data, c->c_plen);
299 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
300 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
301 error("%s: invalid packet type", c->c_name);
305 buffer_consume(&msg, 8); /* cookie */
308 (void) buffer_get_int(&msg);
309 buffer_get_bignum(&msg, rsa->rsa->e);
310 buffer_get_bignum(&msg, rsa->rsa->n);
313 (void) buffer_get_int(&msg);
314 buffer_get_bignum(&msg, rsa->rsa->e);
315 buffer_get_bignum(&msg, rsa->rsa->n);
323 hostjump(Key *hostkey)
325 longjmp(kexjmp, (int)hostkey);
329 ssh2_capable(int remote_major, int remote_minor)
331 switch (remote_major) {
333 if (remote_minor == 99)
349 packet_set_connection(c->c_fd, c->c_fd);
351 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
352 "ssh-dss": "ssh-rsa";
353 c->c_kex = kex_setup(myproposal);
354 c->c_kex->verify_host_key = hostjump;
356 if (!(j = setjmp(kexjmp))) {
358 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
359 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
373 keyprint(con *c, Key *key)
378 fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
379 key_write(key, stdout);
384 tcpconnect(char *host)
386 struct addrinfo hints, *ai, *aitop;
387 char strport[NI_MAXSERV];
390 snprintf(strport, sizeof strport, "%d", ssh_port);
391 memset(&hints, 0, sizeof(hints));
392 hints.ai_family = IPv4or6;
393 hints.ai_socktype = SOCK_STREAM;
394 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
395 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
396 for (ai = aitop; ai; ai = ai->ai_next) {
397 s = socket(ai->ai_family, SOCK_STREAM, 0);
399 error("socket: %s", strerror(errno));
402 if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
403 fatal("F_SETFL: %s", strerror(errno));
404 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
405 errno != EINPROGRESS)
406 error("connect (`%s'): %s", host, strerror(errno));
417 conalloc(char *iname, char *oname, int keytype)
420 char *namebase, *name, *namelist;
422 namebase = namelist = xstrdup(iname);
425 name = xstrsep(&namelist, ",");
430 } while ((s = tcpconnect(name)) < 0);
433 fatal("conalloc: fdno %d too high", s);
434 if (fdcon[s].c_status)
435 fatal("conalloc: attempt to reuse fdno %d", s);
438 fdcon[s].c_status = CS_CON;
439 fdcon[s].c_namebase = namebase;
440 fdcon[s].c_name = name;
441 fdcon[s].c_namelist = namelist;
442 fdcon[s].c_output_name = xstrdup(oname);
443 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
446 fdcon[s].c_keytype = keytype;
447 gettimeofday(&fdcon[s].c_tv, NULL);
448 fdcon[s].c_tv.tv_sec += timeout;
449 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
450 FD_SET(s, read_wait);
458 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
459 fatal("confree: attempt to free bad fdno %d", s);
461 xfree(fdcon[s].c_namebase);
462 xfree(fdcon[s].c_output_name);
463 if (fdcon[s].c_status == CS_KEYS)
464 xfree(fdcon[s].c_data);
465 fdcon[s].c_status = CS_UNUSED;
466 fdcon[s].c_keytype = 0;
467 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
468 FD_CLR(s, read_wait);
475 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
476 gettimeofday(&fdcon[s].c_tv, NULL);
477 fdcon[s].c_tv.tv_sec += timeout;
478 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
487 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
500 bufsiz = sizeof(buf);
502 while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
508 if (errno != ECONNREFUSED)
509 error("read (%s): %s", c->c_name, strerror(errno));
513 if (*cp != '\n' && *cp != '\r') {
514 error("%s: bad greeting", c->c_name);
519 if (c->c_keytype != KT_RSA1) {
520 int remote_major, remote_minor;
521 char remote_version[sizeof buf];
523 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
524 &remote_major, &remote_minor, remote_version) == 3)
525 compat_datafellows(remote_version);
528 if (!ssh2_capable(remote_major, remote_minor)) {
529 debug("%s doesn't support ssh2", c->c_name);
534 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
535 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
536 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
537 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
538 if (atomicio(write, s, buf, n) != n) {
539 error("write (%s): %s", c->c_name, strerror(errno));
543 if (c->c_keytype != KT_RSA1) {
544 keyprint(c, keygrab_ssh2(c));
548 c->c_status = CS_SIZE;
558 if (c->c_status == CS_CON) {
562 n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
564 error("read (%s): %s", c->c_name, strerror(errno));
570 if (c->c_off == c->c_len)
571 switch (c->c_status) {
573 c->c_plen = htonl(c->c_plen);
574 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
576 c->c_data = xmalloc(c->c_len);
577 c->c_status = CS_KEYS;
580 keyprint(c, keygrab_ssh1(c));
585 fatal("conread: invalid status %d", c->c_status);
596 struct timeval seltime, now;
600 gettimeofday(&now, NULL);
603 if (c && (c->c_tv.tv_sec > now.tv_sec ||
604 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
606 seltime.tv_sec -= now.tv_sec;
607 seltime.tv_usec -= now.tv_usec;
608 if (seltime.tv_usec < 0) {
609 seltime.tv_usec += 1000000;
613 seltime.tv_sec = seltime.tv_usec = 0;
615 r = xmalloc(read_wait_size);
616 memcpy(r, read_wait, read_wait_size);
617 e = xmalloc(read_wait_size);
618 memcpy(e, read_wait, read_wait_size);
620 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
621 (errno == EAGAIN || errno == EINTR))
624 for (i = 0; i < maxfd; i++) {
625 if (FD_ISSET(i, e)) {
626 error("%s: exception!", fdcon[i].c_name);
628 } else if (FD_ISSET(i, r))
635 while (c && (c->c_tv.tv_sec < now.tv_sec ||
636 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
639 c = c->c_link.tqe_next;
647 char *name = strnnsep(&host, " \t\n");
650 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
651 if (get_keytypes & j) {
652 while (ncon >= MAXCON)
654 conalloc(name, *host ? host : name, j);
660 fatal_callback(void *arg)
669 fprintf(stderr, "Usage: %s [options] host ...\n",
671 fprintf(stderr, "Options:\n");
672 fprintf(stderr, " -f file Read hosts or addresses from file.\n");
673 fprintf(stderr, " -p port Connect to the specified port.\n");
674 fprintf(stderr, " -t keytype Specify the host key type.\n");
675 fprintf(stderr, " -T timeout Set connection timeout.\n");
676 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
677 fprintf(stderr, " -4 Use IPv4 only.\n");
678 fprintf(stderr, " -6 Use IPv6 only.\n");
683 main(int argc, char **argv)
685 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
686 int opt, fopt_count = 0;
692 __progname = get_progname(argv[0]);
698 while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
701 ssh_port = a2port(optarg);
703 fprintf(stderr, "Bad port '%s'\n", optarg);
708 timeout = atoi(optarg);
715 log_level = SYSLOG_LEVEL_DEBUG1;
717 else if (log_level < SYSLOG_LEVEL_DEBUG3)
720 fatal("Too high debugging level.");
723 if (strcmp(optarg, "-") == 0)
725 argv[fopt_count++] = optarg;
729 tname = strtok(optarg, ",");
731 int type = key_type_from_name(tname);
734 get_keytypes |= KT_RSA1;
737 get_keytypes |= KT_DSA;
740 get_keytypes |= KT_RSA;
743 fatal("unknown key type %s\n", tname);
745 tname = strtok(NULL, ",");
759 if (optind == argc && !fopt_count)
762 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
763 fatal_add_cleanup(fatal_callback, NULL);
766 maxfd = fdlim_get(1);
768 fatal("%s: fdlim_get: bad value", __progname);
769 if (maxfd > MAXMAXFD)
772 fatal("%s: not enough file descriptors", __progname);
773 if (maxfd > fdlim_get(0))
775 fdcon = xmalloc(maxfd * sizeof(con));
776 memset(fdcon, 0, maxfd * sizeof(con));
778 read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
779 read_wait = xmalloc(read_wait_size);
780 memset(read_wait, 0, read_wait_size);
787 for (j = 0; j < fopt_count; j++) {
788 lb = Linebuf_alloc(argv[j], error);
789 while ((line = Linebuf_getline(lb)) != NULL)
795 while (optind < argc)
796 do_host(argv[optind++]);