1 /* $OpenBSD: ssh-keyscan.c,v 1.82 2010/06/22 04:54:30 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 */
110 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
113 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
115 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
118 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
127 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
133 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
134 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
137 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
139 #elif defined (HAVE_SETDTABLESIZE)
146 * This is an strsep function that returns a null field for adjacent
147 * separators. This is the same as the 4.4BSD strsep, but different from the
148 * one in the GNU libc.
151 xstrsep(char **str, const char *delim)
159 e = s + strcspn(s, delim);
169 * Get the next non-null token (like GNU strsep). Strsep() will return a
170 * null token for two adjacent separators, so we may have to loop.
173 strnnsep(char **stringp, char *delim)
178 tok = xstrsep(stringp, delim);
179 } while (tok && *tok == '\0');
191 rsa = key_new(KEY_RSA1);
193 buffer_append(&msg, c->c_data, c->c_plen);
194 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
195 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
196 error("%s: invalid packet type", c->c_name);
200 buffer_consume(&msg, 8); /* cookie */
203 (void) buffer_get_int(&msg);
204 buffer_get_bignum(&msg, rsa->rsa->e);
205 buffer_get_bignum(&msg, rsa->rsa->n);
208 (void) buffer_get_int(&msg);
209 buffer_get_bignum(&msg, rsa->rsa->e);
210 buffer_get_bignum(&msg, rsa->rsa->n);
218 hostjump(Key *hostkey)
220 kexjmp_key = hostkey;
225 ssh2_capable(int remote_major, int remote_minor)
227 switch (remote_major) {
229 if (remote_minor == 99)
245 packet_set_connection(c->c_fd, c->c_fd);
247 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
248 "ssh-dss": "ssh-rsa";
249 c->c_kex = kex_setup(myproposal);
250 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
251 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
252 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
253 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
254 c->c_kex->verify_host_key = hostjump;
256 if (!(j = setjmp(kexjmp))) {
258 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
259 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
267 return j < 0? NULL : kexjmp_key;
271 keyprint(con *c, Key *key)
273 char *host = c->c_output_name ? c->c_output_name : c->c_name;
277 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
278 fatal("host_hash failed");
280 fprintf(stdout, "%s ", host);
281 key_write(key, stdout);
286 tcpconnect(char *host)
288 struct addrinfo hints, *ai, *aitop;
289 char strport[NI_MAXSERV];
292 snprintf(strport, sizeof strport, "%d", ssh_port);
293 memset(&hints, 0, sizeof(hints));
294 hints.ai_family = IPv4or6;
295 hints.ai_socktype = SOCK_STREAM;
296 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
297 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
298 for (ai = aitop; ai; ai = ai->ai_next) {
299 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
301 error("socket: %s", strerror(errno));
304 if (set_nonblock(s) == -1)
305 fatal("%s: set_nonblock(%d)", __func__, s);
306 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
307 errno != EINPROGRESS)
308 error("connect (`%s'): %s", host, strerror(errno));
319 conalloc(char *iname, char *oname, int keytype)
321 char *namebase, *name, *namelist;
324 namebase = namelist = xstrdup(iname);
327 name = xstrsep(&namelist, ",");
332 } while ((s = tcpconnect(name)) < 0);
335 fatal("conalloc: fdno %d too high", s);
336 if (fdcon[s].c_status)
337 fatal("conalloc: attempt to reuse fdno %d", s);
340 fdcon[s].c_status = CS_CON;
341 fdcon[s].c_namebase = namebase;
342 fdcon[s].c_name = name;
343 fdcon[s].c_namelist = namelist;
344 fdcon[s].c_output_name = xstrdup(oname);
345 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
348 fdcon[s].c_keytype = keytype;
349 gettimeofday(&fdcon[s].c_tv, NULL);
350 fdcon[s].c_tv.tv_sec += timeout;
351 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
352 FD_SET(s, read_wait);
360 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
361 fatal("confree: attempt to free bad fdno %d", s);
363 xfree(fdcon[s].c_namebase);
364 xfree(fdcon[s].c_output_name);
365 if (fdcon[s].c_status == CS_KEYS)
366 xfree(fdcon[s].c_data);
367 fdcon[s].c_status = CS_UNUSED;
368 fdcon[s].c_keytype = 0;
369 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
370 FD_CLR(s, read_wait);
377 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
378 gettimeofday(&fdcon[s].c_tv, NULL);
379 fdcon[s].c_tv.tv_sec += timeout;
380 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
389 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
397 int n = 0, remote_major = 0, remote_minor = 0;
399 char remote_version[sizeof buf];
404 memset(buf, '\0', sizeof(buf));
405 bufsiz = sizeof(buf);
408 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
413 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
419 error("%s: Connection closed by remote host", c->c_name);
424 error("read (%s): %s", c->c_name, strerror(errno));
430 if (*cp != '\n' && *cp != '\r') {
431 error("%s: bad greeting", c->c_name);
436 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
437 &remote_major, &remote_minor, remote_version) == 3)
438 compat_datafellows(remote_version);
441 if (c->c_keytype != KT_RSA1) {
442 if (!ssh2_capable(remote_major, remote_minor)) {
443 debug("%s doesn't support ssh2", c->c_name);
447 } else if (remote_major != 1) {
448 debug("%s doesn't support ssh1", c->c_name);
452 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
453 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
454 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
455 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
456 if (n < 0 || (size_t)n >= sizeof(buf)) {
457 error("snprintf: buffer too small");
461 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
462 error("write (%s): %s", c->c_name, strerror(errno));
466 if (c->c_keytype != KT_RSA1) {
467 keyprint(c, keygrab_ssh2(c));
471 c->c_status = CS_SIZE;
481 if (c->c_status == CS_CON) {
485 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
487 error("read (%s): %s", c->c_name, strerror(errno));
493 if (c->c_off == c->c_len)
494 switch (c->c_status) {
496 c->c_plen = htonl(c->c_plen);
497 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
499 c->c_data = xmalloc(c->c_len);
500 c->c_status = CS_KEYS;
503 keyprint(c, keygrab_ssh1(c));
507 fatal("conread: invalid status %d", c->c_status);
517 struct timeval seltime, now;
522 gettimeofday(&now, NULL);
523 c = TAILQ_FIRST(&tq);
525 if (c && (c->c_tv.tv_sec > now.tv_sec ||
526 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
528 seltime.tv_sec -= now.tv_sec;
529 seltime.tv_usec -= now.tv_usec;
530 if (seltime.tv_usec < 0) {
531 seltime.tv_usec += 1000000;
535 seltime.tv_sec = seltime.tv_usec = 0;
537 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
538 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
539 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
540 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
542 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
543 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
546 for (i = 0; i < maxfd; i++) {
547 if (FD_ISSET(i, e)) {
548 error("%s: exception!", fdcon[i].c_name);
550 } else if (FD_ISSET(i, r))
556 c = TAILQ_FIRST(&tq);
557 while (c && (c->c_tv.tv_sec < now.tv_sec ||
558 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
561 c = TAILQ_NEXT(c, c_link);
569 char *name = strnnsep(&host, " \t\n");
574 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
575 if (get_keytypes & j) {
576 while (ncon >= MAXCON)
578 conalloc(name, *host ? host : name, j);
584 fatal(const char *fmt,...)
589 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
601 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
602 "\t\t [host | addrlist namelist] ...\n",
608 main(int argc, char **argv)
610 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
611 int opt, fopt_count = 0, j;
612 char *tname, *cp, line[NI_MAXHOST];
619 __progname = ssh_get_progname(argv[0]);
624 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
630 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
636 ssh_port = a2port(optarg);
638 fprintf(stderr, "Bad port '%s'\n", optarg);
643 timeout = convtime(optarg);
644 if (timeout == -1 || timeout == 0) {
645 fprintf(stderr, "Bad timeout '%s'\n", optarg);
652 log_level = SYSLOG_LEVEL_DEBUG1;
654 else if (log_level < SYSLOG_LEVEL_DEBUG3)
657 fatal("Too high debugging level.");
660 if (strcmp(optarg, "-") == 0)
662 argv[fopt_count++] = optarg;
666 tname = strtok(optarg, ",");
668 int type = key_type_from_name(tname);
671 get_keytypes |= KT_RSA1;
674 get_keytypes |= KT_DSA;
677 get_keytypes |= KT_RSA;
680 fatal("unknown key type %s", tname);
682 tname = strtok(NULL, ",");
696 if (optind == argc && !fopt_count)
699 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
701 maxfd = fdlim_get(1);
703 fatal("%s: fdlim_get: bad value", __progname);
704 if (maxfd > MAXMAXFD)
707 fatal("%s: not enough file descriptors", __progname);
708 if (maxfd > fdlim_get(0))
710 fdcon = xcalloc(maxfd, sizeof(con));
712 read_wait_nfdset = howmany(maxfd, NFDBITS);
713 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
715 for (j = 0; j < fopt_count; j++) {
718 else if ((fp = fopen(argv[j], "r")) == NULL)
719 fatal("%s: %s: %s", __progname, argv[j],
723 while (read_keyfile_line(fp,
724 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
726 /* Chomp off trailing whitespace and comments */
727 if ((cp = strchr(line, '#')) == NULL)
728 cp = line + strlen(line) - 1;
730 if (*cp == ' ' || *cp == '\t' ||
731 *cp == '\n' || *cp == '#')
737 /* Skip empty lines */
745 fatal("%s: %s: %s", __progname, argv[j],
751 while (optind < argc)
752 do_host(argv[optind++]);