1 /* $OpenBSD: ssh-keyscan.c,v 1.78 2009/01/22 10:02:34 djm 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 #ifdef HAVE_SYS_TIME_H
15 # include <sys/time.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
21 #include <openssl/bn.h>
41 #include "myproposal.h"
49 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
50 Default value is AF_UNSPEC means both IPv4 and IPv6. */
51 int IPv4or6 = AF_UNSPEC;
53 int ssh_port = SSH_DEFAULT_PORT;
59 int get_keytypes = KT_RSA; /* Get only RSA keys by default */
61 int hash_hosts = 0; /* Hash hostname on output */
65 /* The number of seconds after which to give up on a TCP connection */
69 #define MAXCON (maxfd - 10)
71 extern char *__progname;
73 size_t read_wait_nfdset;
75 int nonfatal_fatal = 0;
80 * Keep a connection structure for each file descriptor. The state
81 * associated with file descriptor n is held in fdcon[n].
83 typedef struct Connection {
84 u_char c_status; /* State of connection on this file desc. */
85 #define CS_UNUSED 0 /* File descriptor unused */
86 #define CS_CON 1 /* Waiting to connect/read greeting */
87 #define CS_SIZE 2 /* Waiting to read initial packet size */
88 #define CS_KEYS 3 /* Waiting to read public key packet */
89 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
90 int c_plen; /* Packet length field for ssh packet */
91 int c_len; /* Total bytes which must be read. */
92 int c_off; /* Length of data read so far. */
93 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
94 char *c_namebase; /* Address to free for c_name and c_namelist */
95 char *c_name; /* Hostname of connection for errors */
96 char *c_namelist; /* Pointer to other possible addresses */
97 char *c_output_name; /* Hostname of connection for output */
98 char *c_data; /* Data read from this fd */
99 Kex *c_kex; /* The key-exchange struct for ssh2 */
100 struct timeval c_tv; /* Time at which connection gets aborted */
101 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
104 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
108 * This is just a wrapper around fgets() to make it usable.
111 /* Stress-test. Increase this later. */
112 #define LINEBUF_SIZE 16
118 const char *filename;
120 void (*errfun) (const char *,...);
124 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
128 if (!(lb = malloc(sizeof(*lb)))) {
130 (*errfun) ("linebuf (%s): malloc failed\n",
131 filename ? filename : "(stdin)");
135 lb->filename = filename;
136 if (!(lb->stream = fopen(filename, "r"))) {
139 (*errfun) ("%s: %s\n", filename, strerror(errno));
143 lb->filename = "(stdin)";
147 if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
149 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
159 Linebuf_free(Linebuf * lb)
168 Linebuf_restart(Linebuf * lb)
170 clearerr(lb->stream);
176 Linebuf_lineno(Linebuf * lb)
183 Linebuf_getline(Linebuf * lb)
191 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
192 if (ferror(lb->stream) && lb->errfun)
193 (*lb->errfun)("%s: %s\n", lb->filename,
199 /* Return it or an error if it fits */
200 if (n > 0 && lb->buf[n - 1] == '\n') {
201 lb->buf[n - 1] = '\0';
204 if (n != lb->size - 1) {
206 (*lb->errfun)("%s: skipping incomplete last line\n",
210 /* Double the buffer if we need more space */
212 if ((p = realloc(lb->buf, lb->size)) == NULL) {
215 (*lb->errfun)("linebuf (%s): realloc failed\n",
226 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
229 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
231 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
234 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
243 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
249 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
250 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
253 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
255 #elif defined (HAVE_SETDTABLESIZE)
262 * This is an strsep function that returns a null field for adjacent
263 * separators. This is the same as the 4.4BSD strsep, but different from the
264 * one in the GNU libc.
267 xstrsep(char **str, const char *delim)
275 e = s + strcspn(s, delim);
285 * Get the next non-null token (like GNU strsep). Strsep() will return a
286 * null token for two adjacent separators, so we may have to loop.
289 strnnsep(char **stringp, char *delim)
294 tok = xstrsep(stringp, delim);
295 } while (tok && *tok == '\0');
307 rsa = key_new(KEY_RSA1);
309 buffer_append(&msg, c->c_data, c->c_plen);
310 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
311 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
312 error("%s: invalid packet type", c->c_name);
316 buffer_consume(&msg, 8); /* cookie */
319 (void) buffer_get_int(&msg);
320 buffer_get_bignum(&msg, rsa->rsa->e);
321 buffer_get_bignum(&msg, rsa->rsa->n);
324 (void) buffer_get_int(&msg);
325 buffer_get_bignum(&msg, rsa->rsa->e);
326 buffer_get_bignum(&msg, rsa->rsa->n);
334 hostjump(Key *hostkey)
336 kexjmp_key = hostkey;
341 ssh2_capable(int remote_major, int remote_minor)
343 switch (remote_major) {
345 if (remote_minor == 99)
361 packet_set_connection(c->c_fd, c->c_fd);
363 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
364 "ssh-dss": "ssh-rsa";
365 c->c_kex = kex_setup(myproposal);
366 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
367 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
368 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
369 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
370 c->c_kex->verify_host_key = hostjump;
372 if (!(j = setjmp(kexjmp))) {
374 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
375 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
383 return j < 0? NULL : kexjmp_key;
387 keyprint(con *c, Key *key)
389 char *host = c->c_output_name ? c->c_output_name : c->c_name;
393 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
394 fatal("host_hash failed");
396 fprintf(stdout, "%s ", host);
397 key_write(key, stdout);
402 tcpconnect(char *host)
404 struct addrinfo hints, *ai, *aitop;
405 char strport[NI_MAXSERV];
408 snprintf(strport, sizeof strport, "%d", ssh_port);
409 memset(&hints, 0, sizeof(hints));
410 hints.ai_family = IPv4or6;
411 hints.ai_socktype = SOCK_STREAM;
412 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
413 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
414 for (ai = aitop; ai; ai = ai->ai_next) {
415 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
417 error("socket: %s", strerror(errno));
420 if (set_nonblock(s) == -1)
421 fatal("%s: set_nonblock(%d)", __func__, s);
422 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
423 errno != EINPROGRESS)
424 error("connect (`%s'): %s", host, strerror(errno));
435 conalloc(char *iname, char *oname, int keytype)
437 char *namebase, *name, *namelist;
440 namebase = namelist = xstrdup(iname);
443 name = xstrsep(&namelist, ",");
448 } while ((s = tcpconnect(name)) < 0);
451 fatal("conalloc: fdno %d too high", s);
452 if (fdcon[s].c_status)
453 fatal("conalloc: attempt to reuse fdno %d", s);
456 fdcon[s].c_status = CS_CON;
457 fdcon[s].c_namebase = namebase;
458 fdcon[s].c_name = name;
459 fdcon[s].c_namelist = namelist;
460 fdcon[s].c_output_name = xstrdup(oname);
461 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
464 fdcon[s].c_keytype = keytype;
465 gettimeofday(&fdcon[s].c_tv, NULL);
466 fdcon[s].c_tv.tv_sec += timeout;
467 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
468 FD_SET(s, read_wait);
476 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
477 fatal("confree: attempt to free bad fdno %d", s);
479 xfree(fdcon[s].c_namebase);
480 xfree(fdcon[s].c_output_name);
481 if (fdcon[s].c_status == CS_KEYS)
482 xfree(fdcon[s].c_data);
483 fdcon[s].c_status = CS_UNUSED;
484 fdcon[s].c_keytype = 0;
485 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
486 FD_CLR(s, read_wait);
493 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
494 gettimeofday(&fdcon[s].c_tv, NULL);
495 fdcon[s].c_tv.tv_sec += timeout;
496 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
505 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
513 int n = 0, remote_major = 0, remote_minor = 0;
515 char remote_version[sizeof buf];
520 memset(buf, '\0', sizeof(buf));
521 bufsiz = sizeof(buf);
524 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
529 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
535 error("%s: Connection closed by remote host", c->c_name);
540 error("read (%s): %s", c->c_name, strerror(errno));
546 if (*cp != '\n' && *cp != '\r') {
547 error("%s: bad greeting", c->c_name);
552 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
553 &remote_major, &remote_minor, remote_version) == 3)
554 compat_datafellows(remote_version);
557 if (c->c_keytype != KT_RSA1) {
558 if (!ssh2_capable(remote_major, remote_minor)) {
559 debug("%s doesn't support ssh2", c->c_name);
563 } else if (remote_major != 1) {
564 debug("%s doesn't support ssh1", c->c_name);
568 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
569 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
570 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
571 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
572 if (n < 0 || (size_t)n >= sizeof(buf)) {
573 error("snprintf: buffer too small");
577 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
578 error("write (%s): %s", c->c_name, strerror(errno));
582 if (c->c_keytype != KT_RSA1) {
583 keyprint(c, keygrab_ssh2(c));
587 c->c_status = CS_SIZE;
597 if (c->c_status == CS_CON) {
601 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
603 error("read (%s): %s", c->c_name, strerror(errno));
609 if (c->c_off == c->c_len)
610 switch (c->c_status) {
612 c->c_plen = htonl(c->c_plen);
613 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
615 c->c_data = xmalloc(c->c_len);
616 c->c_status = CS_KEYS;
619 keyprint(c, keygrab_ssh1(c));
623 fatal("conread: invalid status %d", c->c_status);
633 struct timeval seltime, now;
638 gettimeofday(&now, NULL);
639 c = TAILQ_FIRST(&tq);
641 if (c && (c->c_tv.tv_sec > now.tv_sec ||
642 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
644 seltime.tv_sec -= now.tv_sec;
645 seltime.tv_usec -= now.tv_usec;
646 if (seltime.tv_usec < 0) {
647 seltime.tv_usec += 1000000;
651 seltime.tv_sec = seltime.tv_usec = 0;
653 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
654 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
655 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
656 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
658 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
659 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
662 for (i = 0; i < maxfd; i++) {
663 if (FD_ISSET(i, e)) {
664 error("%s: exception!", fdcon[i].c_name);
666 } else if (FD_ISSET(i, r))
672 c = TAILQ_FIRST(&tq);
673 while (c && (c->c_tv.tv_sec < now.tv_sec ||
674 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
677 c = TAILQ_NEXT(c, c_link);
685 char *name = strnnsep(&host, " \t\n");
690 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
691 if (get_keytypes & j) {
692 while (ncon >= MAXCON)
694 conalloc(name, *host ? host : name, j);
700 fatal(const char *fmt,...)
705 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
717 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
718 "\t\t [host | addrlist namelist] ...\n",
724 main(int argc, char **argv)
726 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
727 int opt, fopt_count = 0;
733 __progname = ssh_get_progname(argv[0]);
738 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
744 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
750 ssh_port = a2port(optarg);
752 fprintf(stderr, "Bad port '%s'\n", optarg);
757 timeout = convtime(optarg);
758 if (timeout == -1 || timeout == 0) {
759 fprintf(stderr, "Bad timeout '%s'\n", optarg);
766 log_level = SYSLOG_LEVEL_DEBUG1;
768 else if (log_level < SYSLOG_LEVEL_DEBUG3)
771 fatal("Too high debugging level.");
774 if (strcmp(optarg, "-") == 0)
776 argv[fopt_count++] = optarg;
780 tname = strtok(optarg, ",");
782 int type = key_type_from_name(tname);
785 get_keytypes |= KT_RSA1;
788 get_keytypes |= KT_DSA;
791 get_keytypes |= KT_RSA;
794 fatal("unknown key type %s", tname);
796 tname = strtok(NULL, ",");
810 if (optind == argc && !fopt_count)
813 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
815 maxfd = fdlim_get(1);
817 fatal("%s: fdlim_get: bad value", __progname);
818 if (maxfd > MAXMAXFD)
821 fatal("%s: not enough file descriptors", __progname);
822 if (maxfd > fdlim_get(0))
824 fdcon = xcalloc(maxfd, sizeof(con));
826 read_wait_nfdset = howmany(maxfd, NFDBITS);
827 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
834 for (j = 0; j < fopt_count; j++) {
835 lb = Linebuf_alloc(argv[j], error);
838 while ((line = Linebuf_getline(lb)) != NULL)
844 while (optind < argc)
845 do_host(argv[optind++]);