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 1.30 2001/10/08 19:05:05 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. */
39 int IPv4or6 = AF_UNSPEC;
41 int ssh_port = SSH_DEFAULT_PORT;
47 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
51 /* The number of seconds after which to give up on a TCP connection */
55 #define MAXCON (maxfd - 10)
57 #ifdef HAVE___PROGNAME
58 extern char *__progname;
63 size_t read_wait_size;
65 int nonfatal_fatal = 0;
70 * Keep a connection structure for each file descriptor. The state
71 * associated with file descriptor n is held in fdcon[n].
73 typedef struct Connection {
74 u_char c_status; /* State of connection on this file desc. */
75 #define CS_UNUSED 0 /* File descriptor unused */
76 #define CS_CON 1 /* Waiting to connect/read greeting */
77 #define CS_SIZE 2 /* Waiting to read initial packet size */
78 #define CS_KEYS 3 /* Waiting to read public key packet */
79 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
80 int c_plen; /* Packet length field for ssh packet */
81 int c_len; /* Total bytes which must be read. */
82 int c_off; /* Length of data read so far. */
83 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
84 char *c_namebase; /* Address to free for c_name and c_namelist */
85 char *c_name; /* Hostname of connection for errors */
86 char *c_namelist; /* Pointer to other possible addresses */
87 char *c_output_name; /* Hostname of connection for output */
88 char *c_data; /* Data read from this fd */
89 Kex *c_kex; /* The key-exchange struct for ssh2 */
90 struct timeval c_tv; /* Time at which connection gets aborted */
91 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
94 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
98 * This is just a wrapper around fgets() to make it usable.
101 /* Stress-test. Increase this later. */
102 #define LINEBUF_SIZE 16
108 const char *filename;
110 void (*errfun) (const char *,...);
114 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
118 if (!(lb = malloc(sizeof(*lb)))) {
120 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
124 lb->filename = filename;
125 if (!(lb->stream = fopen(filename, "r"))) {
128 (*errfun) ("%s: %s\n", filename, strerror(errno));
132 lb->filename = "(stdin)";
136 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
138 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
148 Linebuf_free(Linebuf * lb)
157 Linebuf_restart(Linebuf * lb)
159 clearerr(lb->stream);
165 Linebuf_lineno(Linebuf * lb)
172 Linebuf_getline(Linebuf * lb)
179 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
180 if (ferror(lb->stream) && lb->errfun)
181 (*lb->errfun) ("%s: %s\n", lb->filename,
187 /* Return it or an error if it fits */
188 if (n > 0 && lb->buf[n - 1] == '\n') {
189 lb->buf[n - 1] = '\0';
192 if (n != lb->size - 1) {
194 (*lb->errfun) ("%s: skipping incomplete last line\n",
198 /* Double the buffer if we need more space */
199 if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
201 (*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;
220 #elif defined (HAVE_SYSCONF)
221 return sysconf (_SC_OPEN_MAX);
230 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
235 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
236 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
239 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
241 #elif defined (HAVE_SETDTABLESIZE)
248 * This is an strsep function that returns a null field for adjacent
249 * separators. This is the same as the 4.4BSD strsep, but different from the
250 * one in the GNU libc.
253 xstrsep(char **str, const char *delim)
261 e = s + strcspn(s, delim);
271 * Get the next non-null token (like GNU strsep). Strsep() will return a
272 * null token for two adjacent separators, so we may have to loop.
275 strnnsep(char **stringp, char *delim)
280 tok = xstrsep(stringp, delim);
281 } while (tok && *tok == '\0');
293 rsa = key_new(KEY_RSA1);
295 buffer_append(&msg, c->c_data, c->c_plen);
296 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
297 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
298 error("%s: invalid packet type", c->c_name);
302 buffer_consume(&msg, 8); /* cookie */
305 (void) buffer_get_int(&msg);
306 buffer_get_bignum(&msg, rsa->rsa->e);
307 buffer_get_bignum(&msg, rsa->rsa->n);
310 (void) buffer_get_int(&msg);
311 buffer_get_bignum(&msg, rsa->rsa->e);
312 buffer_get_bignum(&msg, rsa->rsa->n);
320 hostjump(Key *hostkey)
322 kexjmp_key = hostkey;
327 ssh2_capable(int remote_major, int remote_minor)
329 switch (remote_major) {
331 if (remote_minor == 99)
347 packet_set_connection(c->c_fd, c->c_fd);
349 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
350 "ssh-dss": "ssh-rsa";
351 c->c_kex = kex_setup(myproposal);
352 c->c_kex->verify_host_key = hostjump;
354 if (!(j = setjmp(kexjmp))) {
356 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
357 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
365 return j < 0? NULL : kexjmp_key;
369 keyprint(con *c, Key *key)
374 fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
375 key_write(key, stdout);
380 tcpconnect(char *host)
382 struct addrinfo hints, *ai, *aitop;
383 char strport[NI_MAXSERV];
386 snprintf(strport, sizeof strport, "%d", ssh_port);
387 memset(&hints, 0, sizeof(hints));
388 hints.ai_family = IPv4or6;
389 hints.ai_socktype = SOCK_STREAM;
390 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
391 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
392 for (ai = aitop; ai; ai = ai->ai_next) {
393 s = socket(ai->ai_family, SOCK_STREAM, 0);
395 error("socket: %s", strerror(errno));
398 if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
399 fatal("F_SETFL: %s", strerror(errno));
400 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
401 errno != EINPROGRESS)
402 error("connect (`%s'): %s", host, strerror(errno));
413 conalloc(char *iname, char *oname, int keytype)
416 char *namebase, *name, *namelist;
418 namebase = namelist = xstrdup(iname);
421 name = xstrsep(&namelist, ",");
426 } while ((s = tcpconnect(name)) < 0);
429 fatal("conalloc: fdno %d too high", s);
430 if (fdcon[s].c_status)
431 fatal("conalloc: attempt to reuse fdno %d", s);
434 fdcon[s].c_status = CS_CON;
435 fdcon[s].c_namebase = namebase;
436 fdcon[s].c_name = name;
437 fdcon[s].c_namelist = namelist;
438 fdcon[s].c_output_name = xstrdup(oname);
439 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
442 fdcon[s].c_keytype = keytype;
443 gettimeofday(&fdcon[s].c_tv, NULL);
444 fdcon[s].c_tv.tv_sec += timeout;
445 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
446 FD_SET(s, read_wait);
454 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
455 fatal("confree: attempt to free bad fdno %d", s);
457 xfree(fdcon[s].c_namebase);
458 xfree(fdcon[s].c_output_name);
459 if (fdcon[s].c_status == CS_KEYS)
460 xfree(fdcon[s].c_data);
461 fdcon[s].c_status = CS_UNUSED;
462 fdcon[s].c_keytype = 0;
463 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
464 FD_CLR(s, read_wait);
471 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
472 gettimeofday(&fdcon[s].c_tv, NULL);
473 fdcon[s].c_tv.tv_sec += timeout;
474 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
483 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
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));
509 if (*cp != '\n' && *cp != '\r') {
510 error("%s: bad greeting", c->c_name);
515 if (c->c_keytype != KT_RSA1) {
516 int remote_major, remote_minor;
517 char remote_version[sizeof buf];
519 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
520 &remote_major, &remote_minor, remote_version) == 3)
521 compat_datafellows(remote_version);
524 if (!ssh2_capable(remote_major, remote_minor)) {
525 debug("%s doesn't support ssh2", c->c_name);
530 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
531 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
532 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
533 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
534 if (atomicio(write, s, buf, n) != n) {
535 error("write (%s): %s", c->c_name, strerror(errno));
539 if (c->c_keytype != KT_RSA1) {
540 keyprint(c, keygrab_ssh2(c));
544 c->c_status = CS_SIZE;
554 if (c->c_status == CS_CON) {
558 n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
560 error("read (%s): %s", c->c_name, strerror(errno));
566 if (c->c_off == c->c_len)
567 switch (c->c_status) {
569 c->c_plen = htonl(c->c_plen);
570 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
572 c->c_data = xmalloc(c->c_len);
573 c->c_status = CS_KEYS;
576 keyprint(c, keygrab_ssh1(c));
581 fatal("conread: invalid status %d", c->c_status);
592 struct timeval seltime, now;
596 gettimeofday(&now, NULL);
599 if (c && (c->c_tv.tv_sec > now.tv_sec ||
600 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
602 seltime.tv_sec -= now.tv_sec;
603 seltime.tv_usec -= now.tv_usec;
604 if (seltime.tv_usec < 0) {
605 seltime.tv_usec += 1000000;
609 seltime.tv_sec = seltime.tv_usec = 0;
611 r = xmalloc(read_wait_size);
612 memcpy(r, read_wait, read_wait_size);
613 e = xmalloc(read_wait_size);
614 memcpy(e, read_wait, read_wait_size);
616 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
617 (errno == EAGAIN || errno == EINTR))
620 for (i = 0; i < maxfd; i++) {
621 if (FD_ISSET(i, e)) {
622 error("%s: exception!", fdcon[i].c_name);
624 } else if (FD_ISSET(i, r))
631 while (c && (c->c_tv.tv_sec < now.tv_sec ||
632 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
635 c = c->c_link.tqe_next;
643 char *name = strnnsep(&host, " \t\n");
646 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
647 if (get_keytypes & j) {
648 while (ncon >= MAXCON)
650 conalloc(name, *host ? host : name, j);
656 fatal_callback(void *arg)
665 fprintf(stderr, "Usage: %s [options] host ...\n",
667 fprintf(stderr, "Options:\n");
668 fprintf(stderr, " -f file Read hosts or addresses from file.\n");
669 fprintf(stderr, " -p port Connect to the specified port.\n");
670 fprintf(stderr, " -t keytype Specify the host key type.\n");
671 fprintf(stderr, " -T timeout Set connection timeout.\n");
672 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
673 fprintf(stderr, " -4 Use IPv4 only.\n");
674 fprintf(stderr, " -6 Use IPv6 only.\n");
679 main(int argc, char **argv)
681 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
682 int opt, fopt_count = 0;
688 __progname = get_progname(argv[0]);
696 while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
699 ssh_port = a2port(optarg);
701 fprintf(stderr, "Bad port '%s'\n", optarg);
706 timeout = atoi(optarg);
713 log_level = SYSLOG_LEVEL_DEBUG1;
715 else if (log_level < SYSLOG_LEVEL_DEBUG3)
718 fatal("Too high debugging level.");
721 if (strcmp(optarg, "-") == 0)
723 argv[fopt_count++] = optarg;
727 tname = strtok(optarg, ",");
729 int type = key_type_from_name(tname);
732 get_keytypes |= KT_RSA1;
735 get_keytypes |= KT_DSA;
738 get_keytypes |= KT_RSA;
741 fatal("unknown key type %s\n", tname);
743 tname = strtok(NULL, ",");
757 if (optind == argc && !fopt_count)
760 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
761 fatal_add_cleanup(fatal_callback, NULL);
763 maxfd = fdlim_get(1);
765 fatal("%s: fdlim_get: bad value", __progname);
766 if (maxfd > MAXMAXFD)
769 fatal("%s: not enough file descriptors", __progname);
770 if (maxfd > fdlim_get(0))
772 fdcon = xmalloc(maxfd * sizeof(con));
773 memset(fdcon, 0, maxfd * sizeof(con));
775 read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
776 read_wait = xmalloc(read_wait_size);
777 memset(read_wait, 0, read_wait_size);
784 for (j = 0; j < fopt_count; j++) {
785 lb = Linebuf_alloc(argv[j], error);
788 while ((line = Linebuf_getline(lb)) != NULL)
794 while (optind < argc)
795 do_host(argv[optind++]);