1 /* $OpenBSD: ssh-keyscan.c,v 1.85 2011/03/15 10:36:02 okan 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;
60 int get_keytypes = KT_RSA; /* Get only RSA 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 */
111 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
114 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
116 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
119 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
128 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
134 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
135 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
138 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
140 #elif defined (HAVE_SETDTABLESIZE)
147 * This is an strsep function that returns a null field for adjacent
148 * separators. This is the same as the 4.4BSD strsep, but different from the
149 * one in the GNU libc.
152 xstrsep(char **str, const char *delim)
160 e = s + strcspn(s, delim);
170 * Get the next non-null token (like GNU strsep). Strsep() will return a
171 * null token for two adjacent separators, so we may have to loop.
174 strnnsep(char **stringp, char *delim)
179 tok = xstrsep(stringp, delim);
180 } while (tok && *tok == '\0');
192 rsa = key_new(KEY_RSA1);
194 buffer_append(&msg, c->c_data, c->c_plen);
195 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
196 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
197 error("%s: invalid packet type", c->c_name);
201 buffer_consume(&msg, 8); /* cookie */
204 (void) buffer_get_int(&msg);
205 buffer_get_bignum(&msg, rsa->rsa->e);
206 buffer_get_bignum(&msg, rsa->rsa->n);
209 (void) buffer_get_int(&msg);
210 buffer_get_bignum(&msg, rsa->rsa->e);
211 buffer_get_bignum(&msg, rsa->rsa->n);
219 hostjump(Key *hostkey)
221 kexjmp_key = hostkey;
226 ssh2_capable(int remote_major, int remote_minor)
228 switch (remote_major) {
230 if (remote_minor == 99)
246 packet_set_connection(c->c_fd, c->c_fd);
248 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
249 "ssh-dss" : (c->c_keytype == KT_RSA ? "ssh-rsa" :
250 "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521");
251 c->c_kex = kex_setup(myproposal);
252 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
253 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
254 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
255 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
256 c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
257 c->c_kex->verify_host_key = hostjump;
259 if (!(j = setjmp(kexjmp))) {
261 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
262 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
270 return j < 0? NULL : kexjmp_key;
274 keyprint(con *c, Key *key)
276 char *host = c->c_output_name ? c->c_output_name : c->c_name;
280 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
281 fatal("host_hash failed");
283 fprintf(stdout, "%s ", host);
284 key_write(key, stdout);
289 tcpconnect(char *host)
291 struct addrinfo hints, *ai, *aitop;
292 char strport[NI_MAXSERV];
295 snprintf(strport, sizeof strport, "%d", ssh_port);
296 memset(&hints, 0, sizeof(hints));
297 hints.ai_family = IPv4or6;
298 hints.ai_socktype = SOCK_STREAM;
299 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
300 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
301 for (ai = aitop; ai; ai = ai->ai_next) {
302 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
304 error("socket: %s", strerror(errno));
307 if (set_nonblock(s) == -1)
308 fatal("%s: set_nonblock(%d)", __func__, s);
309 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
310 errno != EINPROGRESS)
311 error("connect (`%s'): %s", host, strerror(errno));
322 conalloc(char *iname, char *oname, int keytype)
324 char *namebase, *name, *namelist;
327 namebase = namelist = xstrdup(iname);
330 name = xstrsep(&namelist, ",");
335 } while ((s = tcpconnect(name)) < 0);
338 fatal("conalloc: fdno %d too high", s);
339 if (fdcon[s].c_status)
340 fatal("conalloc: attempt to reuse fdno %d", s);
343 fdcon[s].c_status = CS_CON;
344 fdcon[s].c_namebase = namebase;
345 fdcon[s].c_name = name;
346 fdcon[s].c_namelist = namelist;
347 fdcon[s].c_output_name = xstrdup(oname);
348 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
351 fdcon[s].c_keytype = keytype;
352 gettimeofday(&fdcon[s].c_tv, NULL);
353 fdcon[s].c_tv.tv_sec += timeout;
354 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
355 FD_SET(s, read_wait);
363 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
364 fatal("confree: attempt to free bad fdno %d", s);
366 xfree(fdcon[s].c_namebase);
367 xfree(fdcon[s].c_output_name);
368 if (fdcon[s].c_status == CS_KEYS)
369 xfree(fdcon[s].c_data);
370 fdcon[s].c_status = CS_UNUSED;
371 fdcon[s].c_keytype = 0;
372 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
373 FD_CLR(s, read_wait);
380 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
381 gettimeofday(&fdcon[s].c_tv, NULL);
382 fdcon[s].c_tv.tv_sec += timeout;
383 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
392 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
400 int n = 0, remote_major = 0, remote_minor = 0;
402 char remote_version[sizeof buf];
407 memset(buf, '\0', sizeof(buf));
408 bufsiz = sizeof(buf);
411 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
416 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
422 error("%s: Connection closed by remote host", c->c_name);
427 error("read (%s): %s", c->c_name, strerror(errno));
433 if (*cp != '\n' && *cp != '\r') {
434 error("%s: bad greeting", c->c_name);
439 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
440 &remote_major, &remote_minor, remote_version) == 3)
441 compat_datafellows(remote_version);
444 if (c->c_keytype != KT_RSA1) {
445 if (!ssh2_capable(remote_major, remote_minor)) {
446 debug("%s doesn't support ssh2", c->c_name);
450 } else if (remote_major != 1) {
451 debug("%s doesn't support ssh1", c->c_name);
455 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
456 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
457 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
458 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
459 if (n < 0 || (size_t)n >= sizeof(buf)) {
460 error("snprintf: buffer too small");
464 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
465 error("write (%s): %s", c->c_name, strerror(errno));
469 if (c->c_keytype != KT_RSA1) {
470 keyprint(c, keygrab_ssh2(c));
474 c->c_status = CS_SIZE;
484 if (c->c_status == CS_CON) {
488 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
490 error("read (%s): %s", c->c_name, strerror(errno));
496 if (c->c_off == c->c_len)
497 switch (c->c_status) {
499 c->c_plen = htonl(c->c_plen);
500 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
502 c->c_data = xmalloc(c->c_len);
503 c->c_status = CS_KEYS;
506 keyprint(c, keygrab_ssh1(c));
510 fatal("conread: invalid status %d", c->c_status);
520 struct timeval seltime, now;
525 gettimeofday(&now, NULL);
526 c = TAILQ_FIRST(&tq);
528 if (c && (c->c_tv.tv_sec > now.tv_sec ||
529 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
531 seltime.tv_sec -= now.tv_sec;
532 seltime.tv_usec -= now.tv_usec;
533 if (seltime.tv_usec < 0) {
534 seltime.tv_usec += 1000000;
538 timerclear(&seltime);
540 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
541 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
542 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
543 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
545 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
546 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
549 for (i = 0; i < maxfd; i++) {
550 if (FD_ISSET(i, e)) {
551 error("%s: exception!", fdcon[i].c_name);
553 } else if (FD_ISSET(i, r))
559 c = TAILQ_FIRST(&tq);
560 while (c && (c->c_tv.tv_sec < now.tv_sec ||
561 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
564 c = TAILQ_NEXT(c, c_link);
572 char *name = strnnsep(&host, " \t\n");
577 for (j = KT_RSA1; j <= KT_ECDSA; j *= 2) {
578 if (get_keytypes & j) {
579 while (ncon >= MAXCON)
581 conalloc(name, *host ? host : name, j);
587 fatal(const char *fmt,...)
592 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
604 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
605 "\t\t [host | addrlist namelist] ...\n",
611 main(int argc, char **argv)
613 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
614 int opt, fopt_count = 0, j;
615 char *tname, *cp, line[NI_MAXHOST];
622 __progname = ssh_get_progname(argv[0]);
626 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
632 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
638 ssh_port = a2port(optarg);
640 fprintf(stderr, "Bad port '%s'\n", optarg);
645 timeout = convtime(optarg);
646 if (timeout == -1 || timeout == 0) {
647 fprintf(stderr, "Bad timeout '%s'\n", optarg);
654 log_level = SYSLOG_LEVEL_DEBUG1;
656 else if (log_level < SYSLOG_LEVEL_DEBUG3)
659 fatal("Too high debugging level.");
662 if (strcmp(optarg, "-") == 0)
664 argv[fopt_count++] = optarg;
668 tname = strtok(optarg, ",");
670 int type = key_type_from_name(tname);
673 get_keytypes |= KT_RSA1;
676 get_keytypes |= KT_DSA;
679 get_keytypes |= KT_ECDSA;
682 get_keytypes |= KT_RSA;
685 fatal("unknown key type %s", tname);
687 tname = strtok(NULL, ",");
701 if (optind == argc && !fopt_count)
704 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
706 maxfd = fdlim_get(1);
708 fatal("%s: fdlim_get: bad value", __progname);
709 if (maxfd > MAXMAXFD)
712 fatal("%s: not enough file descriptors", __progname);
713 if (maxfd > fdlim_get(0))
715 fdcon = xcalloc(maxfd, sizeof(con));
717 read_wait_nfdset = howmany(maxfd, NFDBITS);
718 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
720 for (j = 0; j < fopt_count; j++) {
723 else if ((fp = fopen(argv[j], "r")) == NULL)
724 fatal("%s: %s: %s", __progname, argv[j],
728 while (read_keyfile_line(fp,
729 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
731 /* Chomp off trailing whitespace and comments */
732 if ((cp = strchr(line, '#')) == NULL)
733 cp = line + strlen(line) - 1;
735 if (*cp == ' ' || *cp == '\t' ||
736 *cp == '\n' || *cp == '#')
742 /* Skip empty lines */
750 fatal("%s: %s: %s", __progname, argv[j],
756 while (optind < argc)
757 do_host(argv[optind++]);