1 /* $OpenBSD: ssh-keyscan.c,v 1.67 2006/07/12 22:28:52 stevesk 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>
14 #if defined(HAVE_NETDB_H)
21 #include <openssl/bn.h>
29 #include "myproposal.h"
39 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
40 Default value is AF_UNSPEC means both IPv4 and IPv6. */
41 int IPv4or6 = AF_UNSPEC;
43 int ssh_port = SSH_DEFAULT_PORT;
49 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
51 int hash_hosts = 0; /* Hash hostname on output */
55 /* The number of seconds after which to give up on a TCP connection */
59 #define MAXCON (maxfd - 10)
61 extern char *__progname;
63 size_t read_wait_nfdset;
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",
121 filename ? filename : "(stdin)");
125 lb->filename = filename;
126 if (!(lb->stream = fopen(filename, "r"))) {
129 (*errfun) ("%s: %s\n", filename, strerror(errno));
133 lb->filename = "(stdin)";
137 if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
139 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
149 Linebuf_free(Linebuf * lb)
158 Linebuf_restart(Linebuf * lb)
160 clearerr(lb->stream);
166 Linebuf_lineno(Linebuf * lb)
173 Linebuf_getline(Linebuf * lb)
181 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
182 if (ferror(lb->stream) && lb->errfun)
183 (*lb->errfun)("%s: %s\n", lb->filename,
189 /* Return it or an error if it fits */
190 if (n > 0 && lb->buf[n - 1] == '\n') {
191 lb->buf[n - 1] = '\0';
194 if (n != lb->size - 1) {
196 (*lb->errfun)("%s: skipping incomplete last line\n",
200 /* Double the buffer if we need more space */
202 if ((p = realloc(lb->buf, lb->size)) == NULL) {
205 (*lb->errfun)("linebuf (%s): realloc failed\n",
216 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
219 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
221 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
224 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
233 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
239 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
240 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
243 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
245 #elif defined (HAVE_SETDTABLESIZE)
252 * This is an strsep function that returns a null field for adjacent
253 * separators. This is the same as the 4.4BSD strsep, but different from the
254 * one in the GNU libc.
257 xstrsep(char **str, const char *delim)
265 e = s + strcspn(s, delim);
275 * Get the next non-null token (like GNU strsep). Strsep() will return a
276 * null token for two adjacent separators, so we may have to loop.
279 strnnsep(char **stringp, char *delim)
284 tok = xstrsep(stringp, delim);
285 } while (tok && *tok == '\0');
297 rsa = key_new(KEY_RSA1);
299 buffer_append(&msg, c->c_data, c->c_plen);
300 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
301 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
302 error("%s: invalid packet type", c->c_name);
306 buffer_consume(&msg, 8); /* cookie */
309 (void) buffer_get_int(&msg);
310 buffer_get_bignum(&msg, rsa->rsa->e);
311 buffer_get_bignum(&msg, rsa->rsa->n);
314 (void) buffer_get_int(&msg);
315 buffer_get_bignum(&msg, rsa->rsa->e);
316 buffer_get_bignum(&msg, rsa->rsa->n);
324 hostjump(Key *hostkey)
326 kexjmp_key = hostkey;
331 ssh2_capable(int remote_major, int remote_minor)
333 switch (remote_major) {
335 if (remote_minor == 99)
351 packet_set_connection(c->c_fd, c->c_fd);
353 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
354 "ssh-dss": "ssh-rsa";
355 c->c_kex = kex_setup(myproposal);
356 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
357 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
358 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
359 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
360 c->c_kex->verify_host_key = hostjump;
362 if (!(j = setjmp(kexjmp))) {
364 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
365 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
373 return j < 0? NULL : kexjmp_key;
377 keyprint(con *c, Key *key)
379 char *host = c->c_output_name ? c->c_output_name : c->c_name;
383 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
384 fatal("host_hash failed");
386 fprintf(stdout, "%s ", host);
387 key_write(key, stdout);
392 tcpconnect(char *host)
394 struct addrinfo hints, *ai, *aitop;
395 char strport[NI_MAXSERV];
398 snprintf(strport, sizeof strport, "%d", ssh_port);
399 memset(&hints, 0, sizeof(hints));
400 hints.ai_family = IPv4or6;
401 hints.ai_socktype = SOCK_STREAM;
402 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
403 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
404 for (ai = aitop; ai; ai = ai->ai_next) {
405 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
407 error("socket: %s", strerror(errno));
410 if (set_nonblock(s) == -1)
411 fatal("%s: set_nonblock(%d)", __func__, s);
412 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
413 errno != EINPROGRESS)
414 error("connect (`%s'): %s", host, strerror(errno));
425 conalloc(char *iname, char *oname, int keytype)
427 char *namebase, *name, *namelist;
430 namebase = namelist = xstrdup(iname);
433 name = xstrsep(&namelist, ",");
438 } while ((s = tcpconnect(name)) < 0);
441 fatal("conalloc: fdno %d too high", s);
442 if (fdcon[s].c_status)
443 fatal("conalloc: attempt to reuse fdno %d", s);
446 fdcon[s].c_status = CS_CON;
447 fdcon[s].c_namebase = namebase;
448 fdcon[s].c_name = name;
449 fdcon[s].c_namelist = namelist;
450 fdcon[s].c_output_name = xstrdup(oname);
451 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
454 fdcon[s].c_keytype = keytype;
455 gettimeofday(&fdcon[s].c_tv, NULL);
456 fdcon[s].c_tv.tv_sec += timeout;
457 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
458 FD_SET(s, read_wait);
466 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
467 fatal("confree: attempt to free bad fdno %d", s);
469 xfree(fdcon[s].c_namebase);
470 xfree(fdcon[s].c_output_name);
471 if (fdcon[s].c_status == CS_KEYS)
472 xfree(fdcon[s].c_data);
473 fdcon[s].c_status = CS_UNUSED;
474 fdcon[s].c_keytype = 0;
475 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
476 FD_CLR(s, read_wait);
483 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
484 gettimeofday(&fdcon[s].c_tv, NULL);
485 fdcon[s].c_tv.tv_sec += timeout;
486 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
495 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
503 int n = 0, remote_major = 0, remote_minor = 0;
505 char remote_version[sizeof buf];
510 memset(buf, '\0', sizeof(buf));
511 bufsiz = sizeof(buf);
514 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
519 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
525 error("%s: Connection closed by remote host", c->c_name);
530 error("read (%s): %s", c->c_name, strerror(errno));
536 if (*cp != '\n' && *cp != '\r') {
537 error("%s: bad greeting", c->c_name);
542 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
543 &remote_major, &remote_minor, remote_version) == 3)
544 compat_datafellows(remote_version);
547 if (c->c_keytype != KT_RSA1) {
548 if (!ssh2_capable(remote_major, remote_minor)) {
549 debug("%s doesn't support ssh2", c->c_name);
553 } else if (remote_major != 1) {
554 debug("%s doesn't support ssh1", c->c_name);
558 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
559 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
560 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
561 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
562 if (n < 0 || (size_t)n >= sizeof(buf)) {
563 error("snprintf: buffer too small");
567 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
568 error("write (%s): %s", c->c_name, strerror(errno));
572 if (c->c_keytype != KT_RSA1) {
573 keyprint(c, keygrab_ssh2(c));
577 c->c_status = CS_SIZE;
587 if (c->c_status == CS_CON) {
591 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
593 error("read (%s): %s", c->c_name, strerror(errno));
599 if (c->c_off == c->c_len)
600 switch (c->c_status) {
602 c->c_plen = htonl(c->c_plen);
603 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
605 c->c_data = xmalloc(c->c_len);
606 c->c_status = CS_KEYS;
609 keyprint(c, keygrab_ssh1(c));
613 fatal("conread: invalid status %d", c->c_status);
623 struct timeval seltime, now;
628 gettimeofday(&now, NULL);
629 c = TAILQ_FIRST(&tq);
631 if (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))) {
634 seltime.tv_sec -= now.tv_sec;
635 seltime.tv_usec -= now.tv_usec;
636 if (seltime.tv_usec < 0) {
637 seltime.tv_usec += 1000000;
641 seltime.tv_sec = seltime.tv_usec = 0;
643 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
644 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
645 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
646 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
648 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
649 (errno == EAGAIN || errno == EINTR))
652 for (i = 0; i < maxfd; i++) {
653 if (FD_ISSET(i, e)) {
654 error("%s: exception!", fdcon[i].c_name);
656 } else if (FD_ISSET(i, r))
662 c = TAILQ_FIRST(&tq);
663 while (c && (c->c_tv.tv_sec < now.tv_sec ||
664 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
667 c = TAILQ_NEXT(c, c_link);
675 char *name = strnnsep(&host, " \t\n");
680 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
681 if (get_keytypes & j) {
682 while (ncon >= MAXCON)
684 conalloc(name, *host ? host : name, j);
690 fatal(const char *fmt,...)
695 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
706 fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
707 "\t\t [host | addrlist namelist] [...]\n",
713 main(int argc, char **argv)
715 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
716 int opt, fopt_count = 0;
722 __progname = ssh_get_progname(argv[0]);
727 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
733 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
739 ssh_port = a2port(optarg);
741 fprintf(stderr, "Bad port '%s'\n", optarg);
746 timeout = convtime(optarg);
747 if (timeout == -1 || timeout == 0) {
748 fprintf(stderr, "Bad timeout '%s'\n", optarg);
755 log_level = SYSLOG_LEVEL_DEBUG1;
757 else if (log_level < SYSLOG_LEVEL_DEBUG3)
760 fatal("Too high debugging level.");
763 if (strcmp(optarg, "-") == 0)
765 argv[fopt_count++] = optarg;
769 tname = strtok(optarg, ",");
771 int type = key_type_from_name(tname);
774 get_keytypes |= KT_RSA1;
777 get_keytypes |= KT_DSA;
780 get_keytypes |= KT_RSA;
783 fatal("unknown key type %s", tname);
785 tname = strtok(NULL, ",");
799 if (optind == argc && !fopt_count)
802 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
804 maxfd = fdlim_get(1);
806 fatal("%s: fdlim_get: bad value", __progname);
807 if (maxfd > MAXMAXFD)
810 fatal("%s: not enough file descriptors", __progname);
811 if (maxfd > fdlim_get(0))
813 fdcon = xcalloc(maxfd, sizeof(con));
815 read_wait_nfdset = howmany(maxfd, NFDBITS);
816 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
823 for (j = 0; j < fopt_count; j++) {
824 lb = Linebuf_alloc(argv[j], error);
827 while ((line = Linebuf_getline(lb)) != NULL)
833 while (optind < argc)
834 do_host(argv[optind++]);