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 1.57 2005/10/30 04:01:03 djm Exp $");
12 #include "openbsd-compat/sys-queue.h"
14 #include <openssl/bn.h>
23 #include "myproposal.h"
33 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
34 Default value is AF_UNSPEC means both IPv4 and IPv6. */
35 int IPv4or6 = AF_UNSPEC;
37 int ssh_port = SSH_DEFAULT_PORT;
43 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
45 int hash_hosts = 0; /* Hash hostname on output */
49 /* The number of seconds after which to give up on a TCP connection */
53 #define MAXCON (maxfd - 10)
55 extern char *__progname;
57 size_t read_wait_size;
59 int nonfatal_fatal = 0;
64 * Keep a connection structure for each file descriptor. The state
65 * associated with file descriptor n is held in fdcon[n].
67 typedef struct Connection {
68 u_char c_status; /* State of connection on this file desc. */
69 #define CS_UNUSED 0 /* File descriptor unused */
70 #define CS_CON 1 /* Waiting to connect/read greeting */
71 #define CS_SIZE 2 /* Waiting to read initial packet size */
72 #define CS_KEYS 3 /* Waiting to read public key packet */
73 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
74 int c_plen; /* Packet length field for ssh packet */
75 int c_len; /* Total bytes which must be read. */
76 int c_off; /* Length of data read so far. */
77 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
78 char *c_namebase; /* Address to free for c_name and c_namelist */
79 char *c_name; /* Hostname of connection for errors */
80 char *c_namelist; /* Pointer to other possible addresses */
81 char *c_output_name; /* Hostname of connection for output */
82 char *c_data; /* Data read from this fd */
83 Kex *c_kex; /* The key-exchange struct for ssh2 */
84 struct timeval c_tv; /* Time at which connection gets aborted */
85 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
88 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
92 * This is just a wrapper around fgets() to make it usable.
95 /* Stress-test. Increase this later. */
96 #define LINEBUF_SIZE 16
102 const char *filename;
104 void (*errfun) (const char *,...);
108 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
112 if (!(lb = malloc(sizeof(*lb)))) {
114 (*errfun) ("linebuf (%s): malloc failed\n",
115 filename ? filename : "(stdin)");
119 lb->filename = filename;
120 if (!(lb->stream = fopen(filename, "r"))) {
123 (*errfun) ("%s: %s\n", filename, strerror(errno));
127 lb->filename = "(stdin)";
131 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
133 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
143 Linebuf_free(Linebuf * lb)
152 Linebuf_restart(Linebuf * lb)
154 clearerr(lb->stream);
160 Linebuf_lineno(Linebuf * lb)
167 Linebuf_getline(Linebuf * lb)
175 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
176 if (ferror(lb->stream) && lb->errfun)
177 (*lb->errfun)("%s: %s\n", lb->filename,
183 /* Return it or an error if it fits */
184 if (n > 0 && lb->buf[n - 1] == '\n') {
185 lb->buf[n - 1] = '\0';
188 if (n != lb->size - 1) {
190 (*lb->errfun)("%s: skipping incomplete last line\n",
194 /* Double the buffer if we need more space */
196 if ((p = realloc(lb->buf, lb->size)) == NULL) {
199 (*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;
227 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
233 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
234 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
237 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
239 #elif defined (HAVE_SETDTABLESIZE)
246 * This is an strsep function that returns a null field for adjacent
247 * separators. This is the same as the 4.4BSD strsep, but different from the
248 * one in the GNU libc.
251 xstrsep(char **str, const char *delim)
259 e = s + strcspn(s, delim);
269 * Get the next non-null token (like GNU strsep). Strsep() will return a
270 * null token for two adjacent separators, so we may have to loop.
273 strnnsep(char **stringp, char *delim)
278 tok = xstrsep(stringp, delim);
279 } while (tok && *tok == '\0');
291 rsa = key_new(KEY_RSA1);
293 buffer_append(&msg, c->c_data, c->c_plen);
294 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
295 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
296 error("%s: invalid packet type", c->c_name);
300 buffer_consume(&msg, 8); /* cookie */
303 (void) buffer_get_int(&msg);
304 buffer_get_bignum(&msg, rsa->rsa->e);
305 buffer_get_bignum(&msg, rsa->rsa->n);
308 (void) buffer_get_int(&msg);
309 buffer_get_bignum(&msg, rsa->rsa->e);
310 buffer_get_bignum(&msg, rsa->rsa->n);
318 hostjump(Key *hostkey)
320 kexjmp_key = hostkey;
325 ssh2_capable(int remote_major, int remote_minor)
327 switch (remote_major) {
329 if (remote_minor == 99)
345 packet_set_connection(c->c_fd, c->c_fd);
347 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
348 "ssh-dss": "ssh-rsa";
349 c->c_kex = kex_setup(myproposal);
350 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
351 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
352 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
353 c->c_kex->verify_host_key = hostjump;
355 if (!(j = setjmp(kexjmp))) {
357 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
358 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
366 return j < 0? NULL : kexjmp_key;
370 keyprint(con *c, Key *key)
372 char *host = c->c_output_name ? c->c_output_name : c->c_name;
376 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
377 fatal("host_hash failed");
379 fprintf(stdout, "%s ", host);
380 key_write(key, stdout);
385 tcpconnect(char *host)
387 struct addrinfo hints, *ai, *aitop;
388 char strport[NI_MAXSERV];
391 snprintf(strport, sizeof strport, "%d", ssh_port);
392 memset(&hints, 0, sizeof(hints));
393 hints.ai_family = IPv4or6;
394 hints.ai_socktype = SOCK_STREAM;
395 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
396 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
397 for (ai = aitop; ai; ai = ai->ai_next) {
398 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
400 error("socket: %s", strerror(errno));
403 if (set_nonblock(s) == -1)
404 fatal("%s: set_nonblock(%d)", __func__, s);
405 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
406 errno != EINPROGRESS)
407 error("connect (`%s'): %s", host, strerror(errno));
418 conalloc(char *iname, char *oname, int keytype)
420 char *namebase, *name, *namelist;
423 namebase = namelist = xstrdup(iname);
426 name = xstrsep(&namelist, ",");
431 } while ((s = tcpconnect(name)) < 0);
434 fatal("conalloc: fdno %d too high", s);
435 if (fdcon[s].c_status)
436 fatal("conalloc: attempt to reuse fdno %d", s);
439 fdcon[s].c_status = CS_CON;
440 fdcon[s].c_namebase = namebase;
441 fdcon[s].c_name = name;
442 fdcon[s].c_namelist = namelist;
443 fdcon[s].c_output_name = xstrdup(oname);
444 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
447 fdcon[s].c_keytype = keytype;
448 gettimeofday(&fdcon[s].c_tv, NULL);
449 fdcon[s].c_tv.tv_sec += timeout;
450 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
451 FD_SET(s, read_wait);
459 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
460 fatal("confree: attempt to free bad fdno %d", s);
462 xfree(fdcon[s].c_namebase);
463 xfree(fdcon[s].c_output_name);
464 if (fdcon[s].c_status == CS_KEYS)
465 xfree(fdcon[s].c_data);
466 fdcon[s].c_status = CS_UNUSED;
467 fdcon[s].c_keytype = 0;
468 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
469 FD_CLR(s, read_wait);
476 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
477 gettimeofday(&fdcon[s].c_tv, NULL);
478 fdcon[s].c_tv.tv_sec += timeout;
479 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
488 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
496 int n = 0, remote_major = 0, remote_minor = 0;
498 char remote_version[sizeof buf];
503 memset(buf, '\0', sizeof(buf));
504 bufsiz = sizeof(buf);
507 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
512 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
518 error("%s: Connection closed by remote host", c->c_name);
523 error("read (%s): %s", c->c_name, strerror(errno));
529 if (*cp != '\n' && *cp != '\r') {
530 error("%s: bad greeting", c->c_name);
535 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
536 &remote_major, &remote_minor, remote_version) == 3)
537 compat_datafellows(remote_version);
540 if (c->c_keytype != KT_RSA1) {
541 if (!ssh2_capable(remote_major, remote_minor)) {
542 debug("%s doesn't support ssh2", c->c_name);
546 } else if (remote_major != 1) {
547 debug("%s doesn't support ssh1", c->c_name);
551 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
552 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
553 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
554 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
555 if (n < 0 || (size_t)n >= sizeof(buf)) {
556 error("snprintf: buffer too small");
560 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
561 error("write (%s): %s", c->c_name, strerror(errno));
565 if (c->c_keytype != KT_RSA1) {
566 keyprint(c, keygrab_ssh2(c));
570 c->c_status = CS_SIZE;
580 if (c->c_status == CS_CON) {
584 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
586 error("read (%s): %s", c->c_name, strerror(errno));
592 if (c->c_off == c->c_len)
593 switch (c->c_status) {
595 c->c_plen = htonl(c->c_plen);
596 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
598 c->c_data = xmalloc(c->c_len);
599 c->c_status = CS_KEYS;
602 keyprint(c, keygrab_ssh1(c));
607 fatal("conread: invalid status %d", c->c_status);
617 struct timeval seltime, now;
622 gettimeofday(&now, NULL);
623 c = TAILQ_FIRST(&tq);
625 if (c && (c->c_tv.tv_sec > now.tv_sec ||
626 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
628 seltime.tv_sec -= now.tv_sec;
629 seltime.tv_usec -= now.tv_usec;
630 if (seltime.tv_usec < 0) {
631 seltime.tv_usec += 1000000;
635 seltime.tv_sec = seltime.tv_usec = 0;
637 r = xmalloc(read_wait_size);
638 memcpy(r, read_wait, read_wait_size);
639 e = xmalloc(read_wait_size);
640 memcpy(e, read_wait, read_wait_size);
642 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
643 (errno == EAGAIN || errno == EINTR))
646 for (i = 0; i < maxfd; i++) {
647 if (FD_ISSET(i, e)) {
648 error("%s: exception!", fdcon[i].c_name);
650 } else if (FD_ISSET(i, r))
656 c = TAILQ_FIRST(&tq);
657 while (c && (c->c_tv.tv_sec < now.tv_sec ||
658 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
661 c = TAILQ_NEXT(c, c_link);
669 char *name = strnnsep(&host, " \t\n");
674 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
675 if (get_keytypes & j) {
676 while (ncon >= MAXCON)
678 conalloc(name, *host ? host : name, j);
684 fatal(const char *fmt,...)
689 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
700 fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
701 "\t\t [host | addrlist namelist] [...]\n",
707 main(int argc, char **argv)
709 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
710 int opt, fopt_count = 0;
716 __progname = ssh_get_progname(argv[0]);
721 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
727 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
733 ssh_port = a2port(optarg);
735 fprintf(stderr, "Bad port '%s'\n", optarg);
740 timeout = convtime(optarg);
741 if (timeout == -1 || timeout == 0) {
742 fprintf(stderr, "Bad timeout '%s'\n", optarg);
749 log_level = SYSLOG_LEVEL_DEBUG1;
751 else if (log_level < SYSLOG_LEVEL_DEBUG3)
754 fatal("Too high debugging level.");
757 if (strcmp(optarg, "-") == 0)
759 argv[fopt_count++] = optarg;
763 tname = strtok(optarg, ",");
765 int type = key_type_from_name(tname);
768 get_keytypes |= KT_RSA1;
771 get_keytypes |= KT_DSA;
774 get_keytypes |= KT_RSA;
777 fatal("unknown key type %s", tname);
779 tname = strtok(NULL, ",");
793 if (optind == argc && !fopt_count)
796 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
798 maxfd = fdlim_get(1);
800 fatal("%s: fdlim_get: bad value", __progname);
801 if (maxfd > MAXMAXFD)
804 fatal("%s: not enough file descriptors", __progname);
805 if (maxfd > fdlim_get(0))
807 fdcon = xmalloc(maxfd * sizeof(con));
808 memset(fdcon, 0, maxfd * sizeof(con));
810 read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
811 read_wait = xmalloc(read_wait_size);
812 memset(read_wait, 0, read_wait_size);
819 for (j = 0; j < fopt_count; j++) {
820 lb = Linebuf_alloc(argv[j], error);
823 while ((line = Linebuf_getline(lb)) != NULL)
829 while (optind < argc)
830 do_host(argv[optind++]);