1 /* $OpenBSD: ssh-keyscan.c,v 1.68 2006/07/17 01:31:10 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)
22 #include <openssl/bn.h>
30 #include "myproposal.h"
40 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
41 Default value is AF_UNSPEC means both IPv4 and IPv6. */
42 int IPv4or6 = AF_UNSPEC;
44 int ssh_port = SSH_DEFAULT_PORT;
50 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
52 int hash_hosts = 0; /* Hash hostname on output */
56 /* The number of seconds after which to give up on a TCP connection */
60 #define MAXCON (maxfd - 10)
62 extern char *__progname;
64 size_t read_wait_nfdset;
66 int nonfatal_fatal = 0;
71 * Keep a connection structure for each file descriptor. The state
72 * associated with file descriptor n is held in fdcon[n].
74 typedef struct Connection {
75 u_char c_status; /* State of connection on this file desc. */
76 #define CS_UNUSED 0 /* File descriptor unused */
77 #define CS_CON 1 /* Waiting to connect/read greeting */
78 #define CS_SIZE 2 /* Waiting to read initial packet size */
79 #define CS_KEYS 3 /* Waiting to read public key packet */
80 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
81 int c_plen; /* Packet length field for ssh packet */
82 int c_len; /* Total bytes which must be read. */
83 int c_off; /* Length of data read so far. */
84 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
85 char *c_namebase; /* Address to free for c_name and c_namelist */
86 char *c_name; /* Hostname of connection for errors */
87 char *c_namelist; /* Pointer to other possible addresses */
88 char *c_output_name; /* Hostname of connection for output */
89 char *c_data; /* Data read from this fd */
90 Kex *c_kex; /* The key-exchange struct for ssh2 */
91 struct timeval c_tv; /* Time at which connection gets aborted */
92 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
95 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
99 * This is just a wrapper around fgets() to make it usable.
102 /* Stress-test. Increase this later. */
103 #define LINEBUF_SIZE 16
109 const char *filename;
111 void (*errfun) (const char *,...);
115 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
119 if (!(lb = malloc(sizeof(*lb)))) {
121 (*errfun) ("linebuf (%s): malloc failed\n",
122 filename ? filename : "(stdin)");
126 lb->filename = filename;
127 if (!(lb->stream = fopen(filename, "r"))) {
130 (*errfun) ("%s: %s\n", filename, strerror(errno));
134 lb->filename = "(stdin)";
138 if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
140 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
150 Linebuf_free(Linebuf * lb)
159 Linebuf_restart(Linebuf * lb)
161 clearerr(lb->stream);
167 Linebuf_lineno(Linebuf * lb)
174 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 */
203 if ((p = realloc(lb->buf, lb->size)) == NULL) {
206 (*lb->errfun)("linebuf (%s): realloc failed\n",
217 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
220 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
222 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
225 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
234 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
240 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
241 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
244 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
246 #elif defined (HAVE_SETDTABLESIZE)
253 * This is an strsep function that returns a null field for adjacent
254 * separators. This is the same as the 4.4BSD strsep, but different from the
255 * one in the GNU libc.
258 xstrsep(char **str, const char *delim)
266 e = s + strcspn(s, delim);
276 * Get the next non-null token (like GNU strsep). Strsep() will return a
277 * null token for two adjacent separators, so we may have to loop.
280 strnnsep(char **stringp, char *delim)
285 tok = xstrsep(stringp, delim);
286 } while (tok && *tok == '\0');
298 rsa = key_new(KEY_RSA1);
300 buffer_append(&msg, c->c_data, c->c_plen);
301 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
302 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
303 error("%s: invalid packet type", c->c_name);
307 buffer_consume(&msg, 8); /* cookie */
310 (void) buffer_get_int(&msg);
311 buffer_get_bignum(&msg, rsa->rsa->e);
312 buffer_get_bignum(&msg, rsa->rsa->n);
315 (void) buffer_get_int(&msg);
316 buffer_get_bignum(&msg, rsa->rsa->e);
317 buffer_get_bignum(&msg, rsa->rsa->n);
325 hostjump(Key *hostkey)
327 kexjmp_key = hostkey;
332 ssh2_capable(int remote_major, int remote_minor)
334 switch (remote_major) {
336 if (remote_minor == 99)
352 packet_set_connection(c->c_fd, c->c_fd);
354 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
355 "ssh-dss": "ssh-rsa";
356 c->c_kex = kex_setup(myproposal);
357 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
358 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
359 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
360 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
361 c->c_kex->verify_host_key = hostjump;
363 if (!(j = setjmp(kexjmp))) {
365 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
366 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
374 return j < 0? NULL : kexjmp_key;
378 keyprint(con *c, Key *key)
380 char *host = c->c_output_name ? c->c_output_name : c->c_name;
384 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
385 fatal("host_hash failed");
387 fprintf(stdout, "%s ", host);
388 key_write(key, stdout);
393 tcpconnect(char *host)
395 struct addrinfo hints, *ai, *aitop;
396 char strport[NI_MAXSERV];
399 snprintf(strport, sizeof strport, "%d", ssh_port);
400 memset(&hints, 0, sizeof(hints));
401 hints.ai_family = IPv4or6;
402 hints.ai_socktype = SOCK_STREAM;
403 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
404 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
405 for (ai = aitop; ai; ai = ai->ai_next) {
406 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
408 error("socket: %s", strerror(errno));
411 if (set_nonblock(s) == -1)
412 fatal("%s: set_nonblock(%d)", __func__, s);
413 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
414 errno != EINPROGRESS)
415 error("connect (`%s'): %s", host, strerror(errno));
426 conalloc(char *iname, char *oname, int keytype)
428 char *namebase, *name, *namelist;
431 namebase = namelist = xstrdup(iname);
434 name = xstrsep(&namelist, ",");
439 } while ((s = tcpconnect(name)) < 0);
442 fatal("conalloc: fdno %d too high", s);
443 if (fdcon[s].c_status)
444 fatal("conalloc: attempt to reuse fdno %d", s);
447 fdcon[s].c_status = CS_CON;
448 fdcon[s].c_namebase = namebase;
449 fdcon[s].c_name = name;
450 fdcon[s].c_namelist = namelist;
451 fdcon[s].c_output_name = xstrdup(oname);
452 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
455 fdcon[s].c_keytype = keytype;
456 gettimeofday(&fdcon[s].c_tv, NULL);
457 fdcon[s].c_tv.tv_sec += timeout;
458 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
459 FD_SET(s, read_wait);
467 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
468 fatal("confree: attempt to free bad fdno %d", s);
470 xfree(fdcon[s].c_namebase);
471 xfree(fdcon[s].c_output_name);
472 if (fdcon[s].c_status == CS_KEYS)
473 xfree(fdcon[s].c_data);
474 fdcon[s].c_status = CS_UNUSED;
475 fdcon[s].c_keytype = 0;
476 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
477 FD_CLR(s, read_wait);
484 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
485 gettimeofday(&fdcon[s].c_tv, NULL);
486 fdcon[s].c_tv.tv_sec += timeout;
487 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
496 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
504 int n = 0, remote_major = 0, remote_minor = 0;
506 char remote_version[sizeof buf];
511 memset(buf, '\0', sizeof(buf));
512 bufsiz = sizeof(buf);
515 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
520 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
526 error("%s: Connection closed by remote host", c->c_name);
531 error("read (%s): %s", c->c_name, strerror(errno));
537 if (*cp != '\n' && *cp != '\r') {
538 error("%s: bad greeting", c->c_name);
543 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
544 &remote_major, &remote_minor, remote_version) == 3)
545 compat_datafellows(remote_version);
548 if (c->c_keytype != KT_RSA1) {
549 if (!ssh2_capable(remote_major, remote_minor)) {
550 debug("%s doesn't support ssh2", c->c_name);
554 } else if (remote_major != 1) {
555 debug("%s doesn't support ssh1", c->c_name);
559 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
560 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
561 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
562 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
563 if (n < 0 || (size_t)n >= sizeof(buf)) {
564 error("snprintf: buffer too small");
568 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
569 error("write (%s): %s", c->c_name, strerror(errno));
573 if (c->c_keytype != KT_RSA1) {
574 keyprint(c, keygrab_ssh2(c));
578 c->c_status = CS_SIZE;
588 if (c->c_status == CS_CON) {
592 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
594 error("read (%s): %s", c->c_name, strerror(errno));
600 if (c->c_off == c->c_len)
601 switch (c->c_status) {
603 c->c_plen = htonl(c->c_plen);
604 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
606 c->c_data = xmalloc(c->c_len);
607 c->c_status = CS_KEYS;
610 keyprint(c, keygrab_ssh1(c));
614 fatal("conread: invalid status %d", c->c_status);
624 struct timeval seltime, now;
629 gettimeofday(&now, NULL);
630 c = TAILQ_FIRST(&tq);
632 if (c && (c->c_tv.tv_sec > now.tv_sec ||
633 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
635 seltime.tv_sec -= now.tv_sec;
636 seltime.tv_usec -= now.tv_usec;
637 if (seltime.tv_usec < 0) {
638 seltime.tv_usec += 1000000;
642 seltime.tv_sec = seltime.tv_usec = 0;
644 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
645 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
646 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
647 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
649 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
650 (errno == EAGAIN || errno == EINTR))
653 for (i = 0; i < maxfd; i++) {
654 if (FD_ISSET(i, e)) {
655 error("%s: exception!", fdcon[i].c_name);
657 } else if (FD_ISSET(i, r))
663 c = TAILQ_FIRST(&tq);
664 while (c && (c->c_tv.tv_sec < now.tv_sec ||
665 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
668 c = TAILQ_NEXT(c, c_link);
676 char *name = strnnsep(&host, " \t\n");
681 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
682 if (get_keytypes & j) {
683 while (ncon >= MAXCON)
685 conalloc(name, *host ? host : name, j);
691 fatal(const char *fmt,...)
696 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
707 fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
708 "\t\t [host | addrlist namelist] [...]\n",
714 main(int argc, char **argv)
716 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
717 int opt, fopt_count = 0;
723 __progname = ssh_get_progname(argv[0]);
728 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
734 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
740 ssh_port = a2port(optarg);
742 fprintf(stderr, "Bad port '%s'\n", optarg);
747 timeout = convtime(optarg);
748 if (timeout == -1 || timeout == 0) {
749 fprintf(stderr, "Bad timeout '%s'\n", optarg);
756 log_level = SYSLOG_LEVEL_DEBUG1;
758 else if (log_level < SYSLOG_LEVEL_DEBUG3)
761 fatal("Too high debugging level.");
764 if (strcmp(optarg, "-") == 0)
766 argv[fopt_count++] = optarg;
770 tname = strtok(optarg, ",");
772 int type = key_type_from_name(tname);
775 get_keytypes |= KT_RSA1;
778 get_keytypes |= KT_DSA;
781 get_keytypes |= KT_RSA;
784 fatal("unknown key type %s", tname);
786 tname = strtok(NULL, ",");
800 if (optind == argc && !fopt_count)
803 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
805 maxfd = fdlim_get(1);
807 fatal("%s: fdlim_get: bad value", __progname);
808 if (maxfd > MAXMAXFD)
811 fatal("%s: not enough file descriptors", __progname);
812 if (maxfd > fdlim_get(0))
814 fdcon = xcalloc(maxfd, sizeof(con));
816 read_wait_nfdset = howmany(maxfd, NFDBITS);
817 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
824 for (j = 0; j < fopt_count; j++) {
825 lb = Linebuf_alloc(argv[j], error);
828 while ((line = Linebuf_getline(lb)) != NULL)
834 while (optind < argc)
835 do_host(argv[optind++]);