1 /* $OpenBSD: ssh-keyscan.c,v 1.74 2006/10/06 02:29:19 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"
47 #include "pathnames.h"
50 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
51 Default value is AF_UNSPEC means both IPv4 and IPv6. */
52 int IPv4or6 = AF_UNSPEC;
54 int ssh_port = SSH_DEFAULT_PORT;
60 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
62 int hash_hosts = 0; /* Hash hostname on output */
66 /* The number of seconds after which to give up on a TCP connection */
70 #define MAXCON (maxfd - 10)
72 extern char *__progname;
74 size_t read_wait_nfdset;
76 int nonfatal_fatal = 0;
81 * Keep a connection structure for each file descriptor. The state
82 * associated with file descriptor n is held in fdcon[n].
84 typedef struct Connection {
85 u_char c_status; /* State of connection on this file desc. */
86 #define CS_UNUSED 0 /* File descriptor unused */
87 #define CS_CON 1 /* Waiting to connect/read greeting */
88 #define CS_SIZE 2 /* Waiting to read initial packet size */
89 #define CS_KEYS 3 /* Waiting to read public key packet */
90 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
91 int c_plen; /* Packet length field for ssh packet */
92 int c_len; /* Total bytes which must be read. */
93 int c_off; /* Length of data read so far. */
94 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
95 char *c_namebase; /* Address to free for c_name and c_namelist */
96 char *c_name; /* Hostname of connection for errors */
97 char *c_namelist; /* Pointer to other possible addresses */
98 char *c_output_name; /* Hostname of connection for output */
99 char *c_data; /* Data read from this fd */
100 Kex *c_kex; /* The key-exchange struct for ssh2 */
101 struct timeval c_tv; /* Time at which connection gets aborted */
102 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
105 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
109 * This is just a wrapper around fgets() to make it usable.
112 /* Stress-test. Increase this later. */
113 #define LINEBUF_SIZE 16
119 const char *filename;
121 void (*errfun) (const char *,...);
125 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
129 if (!(lb = malloc(sizeof(*lb)))) {
131 (*errfun) ("linebuf (%s): malloc failed\n",
132 filename ? filename : "(stdin)");
136 lb->filename = filename;
137 if (!(lb->stream = fopen(filename, "r"))) {
140 (*errfun) ("%s: %s\n", filename, strerror(errno));
144 lb->filename = "(stdin)";
148 if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
150 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
160 Linebuf_free(Linebuf * lb)
169 Linebuf_restart(Linebuf * lb)
171 clearerr(lb->stream);
177 Linebuf_lineno(Linebuf * lb)
184 Linebuf_getline(Linebuf * lb)
192 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
193 if (ferror(lb->stream) && lb->errfun)
194 (*lb->errfun)("%s: %s\n", lb->filename,
200 /* Return it or an error if it fits */
201 if (n > 0 && lb->buf[n - 1] == '\n') {
202 lb->buf[n - 1] = '\0';
205 if (n != lb->size - 1) {
207 (*lb->errfun)("%s: skipping incomplete last line\n",
211 /* Double the buffer if we need more space */
213 if ((p = realloc(lb->buf, lb->size)) == NULL) {
216 (*lb->errfun)("linebuf (%s): realloc failed\n",
227 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
230 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
232 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
235 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
244 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
250 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
251 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
254 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
256 #elif defined (HAVE_SETDTABLESIZE)
263 * This is an strsep function that returns a null field for adjacent
264 * separators. This is the same as the 4.4BSD strsep, but different from the
265 * one in the GNU libc.
268 xstrsep(char **str, const char *delim)
276 e = s + strcspn(s, delim);
286 * Get the next non-null token (like GNU strsep). Strsep() will return a
287 * null token for two adjacent separators, so we may have to loop.
290 strnnsep(char **stringp, char *delim)
295 tok = xstrsep(stringp, delim);
296 } while (tok && *tok == '\0');
308 rsa = key_new(KEY_RSA1);
310 buffer_append(&msg, c->c_data, c->c_plen);
311 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
312 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
313 error("%s: invalid packet type", c->c_name);
317 buffer_consume(&msg, 8); /* cookie */
320 (void) buffer_get_int(&msg);
321 buffer_get_bignum(&msg, rsa->rsa->e);
322 buffer_get_bignum(&msg, rsa->rsa->n);
325 (void) buffer_get_int(&msg);
326 buffer_get_bignum(&msg, rsa->rsa->e);
327 buffer_get_bignum(&msg, rsa->rsa->n);
335 hostjump(Key *hostkey)
337 kexjmp_key = hostkey;
342 ssh2_capable(int remote_major, int remote_minor)
344 switch (remote_major) {
346 if (remote_minor == 99)
362 packet_set_connection(c->c_fd, c->c_fd);
364 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
365 "ssh-dss": "ssh-rsa";
366 c->c_kex = kex_setup(myproposal);
367 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
368 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
369 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
370 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
371 c->c_kex->verify_host_key = hostjump;
373 if (!(j = setjmp(kexjmp))) {
375 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
376 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
384 return j < 0? NULL : kexjmp_key;
388 keyprint(con *c, Key *key)
390 char *host = c->c_output_name ? c->c_output_name : c->c_name;
394 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
395 fatal("host_hash failed");
397 fprintf(stdout, "%s ", host);
398 key_write(key, stdout);
403 tcpconnect(char *host)
405 struct addrinfo hints, *ai, *aitop;
406 char strport[NI_MAXSERV];
409 snprintf(strport, sizeof strport, "%d", ssh_port);
410 memset(&hints, 0, sizeof(hints));
411 hints.ai_family = IPv4or6;
412 hints.ai_socktype = SOCK_STREAM;
413 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
414 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
415 for (ai = aitop; ai; ai = ai->ai_next) {
416 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
418 error("socket: %s", strerror(errno));
421 if (set_nonblock(s) == -1)
422 fatal("%s: set_nonblock(%d)", __func__, s);
423 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
424 errno != EINPROGRESS)
425 error("connect (`%s'): %s", host, strerror(errno));
436 conalloc(char *iname, char *oname, int keytype)
438 char *namebase, *name, *namelist;
441 namebase = namelist = xstrdup(iname);
444 name = xstrsep(&namelist, ",");
449 } while ((s = tcpconnect(name)) < 0);
452 fatal("conalloc: fdno %d too high", s);
453 if (fdcon[s].c_status)
454 fatal("conalloc: attempt to reuse fdno %d", s);
457 fdcon[s].c_status = CS_CON;
458 fdcon[s].c_namebase = namebase;
459 fdcon[s].c_name = name;
460 fdcon[s].c_namelist = namelist;
461 fdcon[s].c_output_name = xstrdup(oname);
462 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
465 fdcon[s].c_keytype = keytype;
466 gettimeofday(&fdcon[s].c_tv, NULL);
467 fdcon[s].c_tv.tv_sec += timeout;
468 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
469 FD_SET(s, read_wait);
477 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
478 fatal("confree: attempt to free bad fdno %d", s);
480 xfree(fdcon[s].c_namebase);
481 xfree(fdcon[s].c_output_name);
482 if (fdcon[s].c_status == CS_KEYS)
483 xfree(fdcon[s].c_data);
484 fdcon[s].c_status = CS_UNUSED;
485 fdcon[s].c_keytype = 0;
486 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
487 FD_CLR(s, read_wait);
494 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
495 gettimeofday(&fdcon[s].c_tv, NULL);
496 fdcon[s].c_tv.tv_sec += timeout;
497 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
506 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
514 int n = 0, remote_major = 0, remote_minor = 0;
516 char remote_version[sizeof buf];
521 memset(buf, '\0', sizeof(buf));
522 bufsiz = sizeof(buf);
525 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
530 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
536 error("%s: Connection closed by remote host", c->c_name);
541 error("read (%s): %s", c->c_name, strerror(errno));
547 if (*cp != '\n' && *cp != '\r') {
548 error("%s: bad greeting", c->c_name);
553 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
554 &remote_major, &remote_minor, remote_version) == 3)
555 compat_datafellows(remote_version);
558 if (c->c_keytype != KT_RSA1) {
559 if (!ssh2_capable(remote_major, remote_minor)) {
560 debug("%s doesn't support ssh2", c->c_name);
564 } else if (remote_major != 1) {
565 debug("%s doesn't support ssh1", c->c_name);
569 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
570 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
571 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
572 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
573 if (n < 0 || (size_t)n >= sizeof(buf)) {
574 error("snprintf: buffer too small");
578 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
579 error("write (%s): %s", c->c_name, strerror(errno));
583 if (c->c_keytype != KT_RSA1) {
584 keyprint(c, keygrab_ssh2(c));
588 c->c_status = CS_SIZE;
598 if (c->c_status == CS_CON) {
602 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
604 error("read (%s): %s", c->c_name, strerror(errno));
610 if (c->c_off == c->c_len)
611 switch (c->c_status) {
613 c->c_plen = htonl(c->c_plen);
614 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
616 c->c_data = xmalloc(c->c_len);
617 c->c_status = CS_KEYS;
620 keyprint(c, keygrab_ssh1(c));
624 fatal("conread: invalid status %d", c->c_status);
634 struct timeval seltime, now;
639 gettimeofday(&now, NULL);
640 c = TAILQ_FIRST(&tq);
642 if (c && (c->c_tv.tv_sec > now.tv_sec ||
643 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
645 seltime.tv_sec -= now.tv_sec;
646 seltime.tv_usec -= now.tv_usec;
647 if (seltime.tv_usec < 0) {
648 seltime.tv_usec += 1000000;
652 seltime.tv_sec = seltime.tv_usec = 0;
654 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
655 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
656 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
657 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
659 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
660 (errno == EAGAIN || errno == EINTR))
663 for (i = 0; i < maxfd; i++) {
664 if (FD_ISSET(i, e)) {
665 error("%s: exception!", fdcon[i].c_name);
667 } else if (FD_ISSET(i, r))
673 c = TAILQ_FIRST(&tq);
674 while (c && (c->c_tv.tv_sec < now.tv_sec ||
675 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
678 c = TAILQ_NEXT(c, c_link);
686 char *name = strnnsep(&host, " \t\n");
691 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
692 if (get_keytypes & j) {
693 while (ncon >= MAXCON)
695 conalloc(name, *host ? host : name, j);
701 fatal(const char *fmt,...)
706 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
717 fprintf(stderr, "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]);
739 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
745 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
751 ssh_port = a2port(optarg);
753 fprintf(stderr, "Bad port '%s'\n", optarg);
758 timeout = convtime(optarg);
759 if (timeout == -1 || timeout == 0) {
760 fprintf(stderr, "Bad timeout '%s'\n", optarg);
767 log_level = SYSLOG_LEVEL_DEBUG1;
769 else if (log_level < SYSLOG_LEVEL_DEBUG3)
772 fatal("Too high debugging level.");
775 if (strcmp(optarg, "-") == 0)
777 argv[fopt_count++] = optarg;
781 tname = strtok(optarg, ",");
783 int type = key_type_from_name(tname);
786 get_keytypes |= KT_RSA1;
789 get_keytypes |= KT_DSA;
792 get_keytypes |= KT_RSA;
795 fatal("unknown key type %s", tname);
797 tname = strtok(NULL, ",");
811 if (optind == argc && !fopt_count)
814 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
816 maxfd = fdlim_get(1);
818 fatal("%s: fdlim_get: bad value", __progname);
819 if (maxfd > MAXMAXFD)
822 fatal("%s: not enough file descriptors", __progname);
823 if (maxfd > fdlim_get(0))
825 fdcon = xcalloc(maxfd, sizeof(con));
827 read_wait_nfdset = howmany(maxfd, NFDBITS);
828 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
835 for (j = 0; j < fopt_count; j++) {
836 lb = Linebuf_alloc(argv[j], error);
839 while ((line = Linebuf_getline(lb)) != NULL)
845 while (optind < argc)
846 do_host(argv[optind++]);