1 /* $OpenBSD: ssh-keyscan.c,v 1.92 2014/04/29 18:01:49 markus 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;
61 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519;
63 int hash_hosts = 0; /* Hash hostname on output */
67 /* The number of seconds after which to give up on a TCP connection */
71 #define MAXCON (maxfd - 10)
73 extern char *__progname;
75 size_t read_wait_nfdset;
77 int nonfatal_fatal = 0;
82 * Keep a connection structure for each file descriptor. The state
83 * associated with file descriptor n is held in fdcon[n].
85 typedef struct Connection {
86 u_char c_status; /* State of connection on this file desc. */
87 #define CS_UNUSED 0 /* File descriptor unused */
88 #define CS_CON 1 /* Waiting to connect/read greeting */
89 #define CS_SIZE 2 /* Waiting to read initial packet size */
90 #define CS_KEYS 3 /* Waiting to read public key packet */
91 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
92 int c_plen; /* Packet length field for ssh packet */
93 int c_len; /* Total bytes which must be read. */
94 int c_off; /* Length of data read so far. */
95 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
96 char *c_namebase; /* Address to free for c_name and c_namelist */
97 char *c_name; /* Hostname of connection for errors */
98 char *c_namelist; /* Pointer to other possible addresses */
99 char *c_output_name; /* Hostname of connection for output */
100 char *c_data; /* Data read from this fd */
101 Kex *c_kex; /* The key-exchange struct for ssh2 */
102 struct timeval c_tv; /* Time at which connection gets aborted */
103 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
106 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
112 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
115 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
117 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
120 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
129 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
135 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
136 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
139 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
141 #elif defined (HAVE_SETDTABLESIZE)
148 * This is an strsep function that returns a null field for adjacent
149 * separators. This is the same as the 4.4BSD strsep, but different from the
150 * one in the GNU libc.
153 xstrsep(char **str, const char *delim)
161 e = s + strcspn(s, delim);
171 * Get the next non-null token (like GNU strsep). Strsep() will return a
172 * null token for two adjacent separators, so we may have to loop.
175 strnnsep(char **stringp, char *delim)
180 tok = xstrsep(stringp, delim);
181 } while (tok && *tok == '\0');
194 rsa = key_new(KEY_RSA1);
196 buffer_append(&msg, c->c_data, c->c_plen);
197 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
198 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
199 error("%s: invalid packet type", c->c_name);
203 buffer_consume(&msg, 8); /* cookie */
206 (void) buffer_get_int(&msg);
207 buffer_get_bignum(&msg, rsa->rsa->e);
208 buffer_get_bignum(&msg, rsa->rsa->n);
211 (void) buffer_get_int(&msg);
212 buffer_get_bignum(&msg, rsa->rsa->e);
213 buffer_get_bignum(&msg, rsa->rsa->n);
222 hostjump(Key *hostkey)
224 kexjmp_key = hostkey;
229 ssh2_capable(int remote_major, int remote_minor)
231 switch (remote_major) {
233 if (remote_minor == 99)
247 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
250 packet_set_connection(c->c_fd, c->c_fd);
252 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
253 c->c_keytype == KT_DSA ? "ssh-dss" :
254 (c->c_keytype == KT_RSA ? "ssh-rsa" :
255 (c->c_keytype == KT_ED25519 ? "ssh-ed25519" :
256 "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521"));
257 c->c_kex = kex_setup(myproposal);
259 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
260 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
261 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
262 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
263 c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
265 c->c_kex->kex[KEX_C25519_SHA256] = kexc25519_client;
266 c->c_kex->verify_host_key = hostjump;
268 if (!(j = setjmp(kexjmp))) {
270 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
271 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
279 return j < 0? NULL : kexjmp_key;
283 keyprint(con *c, Key *key)
285 char *host = c->c_output_name ? c->c_output_name : c->c_name;
289 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
290 fatal("host_hash failed");
292 fprintf(stdout, "%s ", host);
293 key_write(key, stdout);
298 tcpconnect(char *host)
300 struct addrinfo hints, *ai, *aitop;
301 char strport[NI_MAXSERV];
304 snprintf(strport, sizeof strport, "%d", ssh_port);
305 memset(&hints, 0, sizeof(hints));
306 hints.ai_family = IPv4or6;
307 hints.ai_socktype = SOCK_STREAM;
308 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
309 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
310 for (ai = aitop; ai; ai = ai->ai_next) {
311 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
313 error("socket: %s", strerror(errno));
316 if (set_nonblock(s) == -1)
317 fatal("%s: set_nonblock(%d)", __func__, s);
318 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
319 errno != EINPROGRESS)
320 error("connect (`%s'): %s", host, strerror(errno));
331 conalloc(char *iname, char *oname, int keytype)
333 char *namebase, *name, *namelist;
336 namebase = namelist = xstrdup(iname);
339 name = xstrsep(&namelist, ",");
344 } while ((s = tcpconnect(name)) < 0);
347 fatal("conalloc: fdno %d too high", s);
348 if (fdcon[s].c_status)
349 fatal("conalloc: attempt to reuse fdno %d", s);
352 fdcon[s].c_status = CS_CON;
353 fdcon[s].c_namebase = namebase;
354 fdcon[s].c_name = name;
355 fdcon[s].c_namelist = namelist;
356 fdcon[s].c_output_name = xstrdup(oname);
357 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
360 fdcon[s].c_keytype = keytype;
361 gettimeofday(&fdcon[s].c_tv, NULL);
362 fdcon[s].c_tv.tv_sec += timeout;
363 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
364 FD_SET(s, read_wait);
372 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
373 fatal("confree: attempt to free bad fdno %d", s);
375 free(fdcon[s].c_namebase);
376 free(fdcon[s].c_output_name);
377 if (fdcon[s].c_status == CS_KEYS)
378 free(fdcon[s].c_data);
379 fdcon[s].c_status = CS_UNUSED;
380 fdcon[s].c_keytype = 0;
381 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
382 FD_CLR(s, read_wait);
389 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
390 gettimeofday(&fdcon[s].c_tv, NULL);
391 fdcon[s].c_tv.tv_sec += timeout;
392 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
401 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
409 int n = 0, remote_major = 0, remote_minor = 0;
411 char remote_version[sizeof buf];
416 memset(buf, '\0', sizeof(buf));
417 bufsiz = sizeof(buf);
420 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
425 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
431 error("%s: Connection closed by remote host", c->c_name);
436 error("read (%s): %s", c->c_name, strerror(errno));
442 if (*cp != '\n' && *cp != '\r') {
443 error("%s: bad greeting", c->c_name);
448 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
449 &remote_major, &remote_minor, remote_version) == 3)
450 compat_datafellows(remote_version);
453 if (c->c_keytype != KT_RSA1) {
454 if (!ssh2_capable(remote_major, remote_minor)) {
455 debug("%s doesn't support ssh2", c->c_name);
459 } else if (remote_major != 1) {
460 debug("%s doesn't support ssh1", c->c_name);
464 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
465 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
466 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
467 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
468 if (n < 0 || (size_t)n >= sizeof(buf)) {
469 error("snprintf: buffer too small");
473 if (atomicio(vwrite, s, buf, n) != (size_t)n) {
474 error("write (%s): %s", c->c_name, strerror(errno));
478 if (c->c_keytype != KT_RSA1) {
479 keyprint(c, keygrab_ssh2(c));
483 c->c_status = CS_SIZE;
493 if (c->c_status == CS_CON) {
497 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
499 error("read (%s): %s", c->c_name, strerror(errno));
505 if (c->c_off == c->c_len)
506 switch (c->c_status) {
508 c->c_plen = htonl(c->c_plen);
509 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
511 c->c_data = xmalloc(c->c_len);
512 c->c_status = CS_KEYS;
516 keyprint(c, keygrab_ssh1(c));
521 fatal("conread: invalid status %d", c->c_status);
531 struct timeval seltime, now;
536 gettimeofday(&now, NULL);
537 c = TAILQ_FIRST(&tq);
539 if (c && (c->c_tv.tv_sec > now.tv_sec ||
540 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
542 seltime.tv_sec -= now.tv_sec;
543 seltime.tv_usec -= now.tv_usec;
544 if (seltime.tv_usec < 0) {
545 seltime.tv_usec += 1000000;
549 timerclear(&seltime);
551 r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
552 e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
553 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
554 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
556 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
557 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
560 for (i = 0; i < maxfd; i++) {
561 if (FD_ISSET(i, e)) {
562 error("%s: exception!", fdcon[i].c_name);
564 } else if (FD_ISSET(i, r))
570 c = TAILQ_FIRST(&tq);
571 while (c && (c->c_tv.tv_sec < now.tv_sec ||
572 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
575 c = TAILQ_NEXT(c, c_link);
583 char *name = strnnsep(&host, " \t\n");
588 for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
589 if (get_keytypes & j) {
590 while (ncon >= MAXCON)
592 conalloc(name, *host ? host : name, j);
598 fatal(const char *fmt,...)
603 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
615 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
616 "\t\t [host | addrlist namelist] ...\n",
622 main(int argc, char **argv)
624 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
625 int opt, fopt_count = 0, j;
626 char *tname, *cp, line[NI_MAXHOST];
633 __progname = ssh_get_progname(argv[0]);
637 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
643 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
649 ssh_port = a2port(optarg);
651 fprintf(stderr, "Bad port '%s'\n", optarg);
656 timeout = convtime(optarg);
657 if (timeout == -1 || timeout == 0) {
658 fprintf(stderr, "Bad timeout '%s'\n", optarg);
665 log_level = SYSLOG_LEVEL_DEBUG1;
667 else if (log_level < SYSLOG_LEVEL_DEBUG3)
670 fatal("Too high debugging level.");
673 if (strcmp(optarg, "-") == 0)
675 argv[fopt_count++] = optarg;
679 tname = strtok(optarg, ",");
681 int type = key_type_from_name(tname);
684 get_keytypes |= KT_RSA1;
687 get_keytypes |= KT_DSA;
690 get_keytypes |= KT_ECDSA;
693 get_keytypes |= KT_RSA;
696 get_keytypes |= KT_ED25519;
699 fatal("unknown key type %s", tname);
701 tname = strtok(NULL, ",");
715 if (optind == argc && !fopt_count)
718 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
720 maxfd = fdlim_get(1);
722 fatal("%s: fdlim_get: bad value", __progname);
723 if (maxfd > MAXMAXFD)
726 fatal("%s: not enough file descriptors", __progname);
727 if (maxfd > fdlim_get(0))
729 fdcon = xcalloc(maxfd, sizeof(con));
731 read_wait_nfdset = howmany(maxfd, NFDBITS);
732 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
734 for (j = 0; j < fopt_count; j++) {
737 else if ((fp = fopen(argv[j], "r")) == NULL)
738 fatal("%s: %s: %s", __progname, argv[j],
742 while (read_keyfile_line(fp,
743 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
745 /* Chomp off trailing whitespace and comments */
746 if ((cp = strchr(line, '#')) == NULL)
747 cp = line + strlen(line) - 1;
749 if (*cp == ' ' || *cp == '\t' ||
750 *cp == '\n' || *cp == '#')
756 /* Skip empty lines */
764 fatal("%s: %s: %s", __progname, argv[j],
770 while (optind < argc)
771 do_host(argv[optind++]);