2 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
4 * Modification and redistribution in source and binary forms is
5 * permitted provided that due credit is given to the author and the
6 * OpenBSD project by leaving this copyright notice intact.
10 RCSID("$OpenBSD: ssh-keyscan.c,v 1.41 2003/02/16 17:09:57 markus Exp $");
12 #include "openbsd-compat/sys-queue.h"
14 #include <openssl/bn.h>
23 #include "myproposal.h"
32 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
33 Default value is AF_UNSPEC means both IPv4 and IPv6. */
35 int IPv4or6 = AF_INET;
37 int IPv4or6 = AF_UNSPEC;
40 int ssh_port = SSH_DEFAULT_PORT;
46 int get_keytypes = KT_RSA1; /* Get only RSA1 keys by default */
50 /* The number of seconds after which to give up on a TCP connection */
54 #define MAXCON (maxfd - 10)
56 #ifdef HAVE___PROGNAME
57 extern char *__progname;
62 size_t read_wait_size;
64 int nonfatal_fatal = 0;
69 * Keep a connection structure for each file descriptor. The state
70 * associated with file descriptor n is held in fdcon[n].
72 typedef struct Connection {
73 u_char c_status; /* State of connection on this file desc. */
74 #define CS_UNUSED 0 /* File descriptor unused */
75 #define CS_CON 1 /* Waiting to connect/read greeting */
76 #define CS_SIZE 2 /* Waiting to read initial packet size */
77 #define CS_KEYS 3 /* Waiting to read public key packet */
78 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
79 int c_plen; /* Packet length field for ssh packet */
80 int c_len; /* Total bytes which must be read. */
81 int c_off; /* Length of data read so far. */
82 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
83 char *c_namebase; /* Address to free for c_name and c_namelist */
84 char *c_name; /* Hostname of connection for errors */
85 char *c_namelist; /* Pointer to other possible addresses */
86 char *c_output_name; /* Hostname of connection for output */
87 char *c_data; /* Data read from this fd */
88 Kex *c_kex; /* The key-exchange struct for ssh2 */
89 struct timeval c_tv; /* Time at which connection gets aborted */
90 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
93 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
97 * This is just a wrapper around fgets() to make it usable.
100 /* Stress-test. Increase this later. */
101 #define LINEBUF_SIZE 16
107 const char *filename;
109 void (*errfun) (const char *,...);
113 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
117 if (!(lb = malloc(sizeof(*lb)))) {
119 (*errfun) ("linebuf (%s): malloc failed\n",
120 filename ? filename : "(stdin)");
124 lb->filename = filename;
125 if (!(lb->stream = fopen(filename, "r"))) {
128 (*errfun) ("%s: %s\n", filename, strerror(errno));
132 lb->filename = "(stdin)";
136 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
138 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
148 Linebuf_free(Linebuf * lb)
157 Linebuf_restart(Linebuf * lb)
159 clearerr(lb->stream);
165 Linebuf_lineno(Linebuf * lb)
172 Linebuf_getline(Linebuf * lb)
180 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
181 if (ferror(lb->stream) && lb->errfun)
182 (*lb->errfun)("%s: %s\n", lb->filename,
188 /* Return it or an error if it fits */
189 if (n > 0 && lb->buf[n - 1] == '\n') {
190 lb->buf[n - 1] = '\0';
193 if (n != lb->size - 1) {
195 (*lb->errfun)("%s: skipping incomplete last line\n",
199 /* Double the buffer if we need more space */
201 if ((p = realloc(lb->buf, lb->size)) == NULL) {
204 (*lb->errfun)("linebuf (%s): realloc failed\n",
215 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
218 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
220 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
223 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
224 #elif defined (HAVE_SYSCONF)
225 return sysconf (_SC_OPEN_MAX);
234 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
240 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
241 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
244 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
246 #elif defined (HAVE_SETDTABLESIZE)
253 * This is an strsep function that returns a null field for adjacent
254 * separators. This is the same as the 4.4BSD strsep, but different from the
255 * one in the GNU libc.
258 xstrsep(char **str, const char *delim)
266 e = s + strcspn(s, delim);
276 * Get the next non-null token (like GNU strsep). Strsep() will return a
277 * null token for two adjacent separators, so we may have to loop.
280 strnnsep(char **stringp, char *delim)
285 tok = xstrsep(stringp, delim);
286 } while (tok && *tok == '\0');
298 rsa = key_new(KEY_RSA1);
300 buffer_append(&msg, c->c_data, c->c_plen);
301 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
302 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
303 error("%s: invalid packet type", c->c_name);
307 buffer_consume(&msg, 8); /* cookie */
310 (void) buffer_get_int(&msg);
311 buffer_get_bignum(&msg, rsa->rsa->e);
312 buffer_get_bignum(&msg, rsa->rsa->n);
315 (void) buffer_get_int(&msg);
316 buffer_get_bignum(&msg, rsa->rsa->e);
317 buffer_get_bignum(&msg, rsa->rsa->n);
325 hostjump(Key *hostkey)
327 kexjmp_key = hostkey;
332 ssh2_capable(int remote_major, int remote_minor)
334 switch (remote_major) {
336 if (remote_minor == 99)
352 packet_set_connection(c->c_fd, c->c_fd);
354 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
355 "ssh-dss": "ssh-rsa";
356 c->c_kex = kex_setup(myproposal);
357 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
358 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
359 c->c_kex->verify_host_key = hostjump;
361 if (!(j = setjmp(kexjmp))) {
363 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
364 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
372 return j < 0? NULL : kexjmp_key;
376 keyprint(con *c, Key *key)
381 fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
382 key_write(key, stdout);
387 tcpconnect(char *host)
389 struct addrinfo hints, *ai, *aitop;
390 char strport[NI_MAXSERV];
393 snprintf(strport, sizeof strport, "%d", ssh_port);
394 memset(&hints, 0, sizeof(hints));
395 hints.ai_family = IPv4or6;
396 hints.ai_socktype = SOCK_STREAM;
397 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
398 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
399 for (ai = aitop; ai; ai = ai->ai_next) {
400 s = socket(ai->ai_family, SOCK_STREAM, 0);
402 error("socket: %s", strerror(errno));
405 if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
406 fatal("F_SETFL: %s", strerror(errno));
407 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
408 errno != EINPROGRESS)
409 error("connect (`%s'): %s", host, strerror(errno));
420 conalloc(char *iname, char *oname, int keytype)
422 char *namebase, *name, *namelist;
425 namebase = namelist = xstrdup(iname);
428 name = xstrsep(&namelist, ",");
433 } while ((s = tcpconnect(name)) < 0);
436 fatal("conalloc: fdno %d too high", s);
437 if (fdcon[s].c_status)
438 fatal("conalloc: attempt to reuse fdno %d", s);
441 fdcon[s].c_status = CS_CON;
442 fdcon[s].c_namebase = namebase;
443 fdcon[s].c_name = name;
444 fdcon[s].c_namelist = namelist;
445 fdcon[s].c_output_name = xstrdup(oname);
446 fdcon[s].c_data = (char *) &fdcon[s].c_plen;
449 fdcon[s].c_keytype = keytype;
450 gettimeofday(&fdcon[s].c_tv, NULL);
451 fdcon[s].c_tv.tv_sec += timeout;
452 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
453 FD_SET(s, read_wait);
461 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
462 fatal("confree: attempt to free bad fdno %d", s);
464 xfree(fdcon[s].c_namebase);
465 xfree(fdcon[s].c_output_name);
466 if (fdcon[s].c_status == CS_KEYS)
467 xfree(fdcon[s].c_data);
468 fdcon[s].c_status = CS_UNUSED;
469 fdcon[s].c_keytype = 0;
470 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
471 FD_CLR(s, read_wait);
478 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
479 gettimeofday(&fdcon[s].c_tv, NULL);
480 fdcon[s].c_tv.tv_sec += timeout;
481 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
490 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
498 int remote_major, remote_minor, n = 0;
500 char remote_version[sizeof buf];
504 bufsiz = sizeof(buf);
506 while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
512 if (errno != ECONNREFUSED)
513 error("read (%s): %s", c->c_name, strerror(errno));
518 error("%s: Connection closed by remote host", c->c_name);
522 if (*cp != '\n' && *cp != '\r') {
523 error("%s: bad greeting", c->c_name);
528 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
529 &remote_major, &remote_minor, remote_version) == 3)
530 compat_datafellows(remote_version);
533 if (c->c_keytype != KT_RSA1) {
534 if (!ssh2_capable(remote_major, remote_minor)) {
535 debug("%s doesn't support ssh2", c->c_name);
539 } else if (remote_major != 1) {
540 debug("%s doesn't support ssh1", c->c_name);
544 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
545 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
546 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
547 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
548 if (atomicio(write, s, buf, n) != n) {
549 error("write (%s): %s", c->c_name, strerror(errno));
553 if (c->c_keytype != KT_RSA1) {
554 keyprint(c, keygrab_ssh2(c));
558 c->c_status = CS_SIZE;
568 if (c->c_status == CS_CON) {
572 n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
574 error("read (%s): %s", c->c_name, strerror(errno));
580 if (c->c_off == c->c_len)
581 switch (c->c_status) {
583 c->c_plen = htonl(c->c_plen);
584 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
586 c->c_data = xmalloc(c->c_len);
587 c->c_status = CS_KEYS;
590 keyprint(c, keygrab_ssh1(c));
595 fatal("conread: invalid status %d", c->c_status);
605 struct timeval seltime, now;
610 gettimeofday(&now, NULL);
611 c = TAILQ_FIRST(&tq);
613 if (c && (c->c_tv.tv_sec > now.tv_sec ||
614 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
616 seltime.tv_sec -= now.tv_sec;
617 seltime.tv_usec -= now.tv_usec;
618 if (seltime.tv_usec < 0) {
619 seltime.tv_usec += 1000000;
623 seltime.tv_sec = seltime.tv_usec = 0;
625 r = xmalloc(read_wait_size);
626 memcpy(r, read_wait, read_wait_size);
627 e = xmalloc(read_wait_size);
628 memcpy(e, read_wait, read_wait_size);
630 while (select(maxfd, r, NULL, e, &seltime) == -1 &&
631 (errno == EAGAIN || errno == EINTR))
634 for (i = 0; i < maxfd; i++) {
635 if (FD_ISSET(i, e)) {
636 error("%s: exception!", fdcon[i].c_name);
638 } else if (FD_ISSET(i, r))
644 c = TAILQ_FIRST(&tq);
645 while (c && (c->c_tv.tv_sec < now.tv_sec ||
646 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
649 c = TAILQ_NEXT(c, c_link);
657 char *name = strnnsep(&host, " \t\n");
662 for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
663 if (get_keytypes & j) {
664 while (ncon >= MAXCON)
666 conalloc(name, *host ? host : name, j);
672 fatal(const char *fmt,...)
677 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
688 fprintf(stderr, "usage: %s [-v46] [-p port] [-T timeout] [-f file]\n"
689 "\t\t [host | addrlist namelist] [...]\n",
695 main(int argc, char **argv)
697 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
698 int opt, fopt_count = 0;
704 __progname = get_progname(argv[0]);
712 while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
715 ssh_port = a2port(optarg);
717 fprintf(stderr, "Bad port '%s'\n", optarg);
722 timeout = convtime(optarg);
723 if (timeout == -1 || timeout == 0) {
724 fprintf(stderr, "Bad timeout '%s'\n", optarg);
731 log_level = SYSLOG_LEVEL_DEBUG1;
733 else if (log_level < SYSLOG_LEVEL_DEBUG3)
736 fatal("Too high debugging level.");
739 if (strcmp(optarg, "-") == 0)
741 argv[fopt_count++] = optarg;
745 tname = strtok(optarg, ",");
747 int type = key_type_from_name(tname);
750 get_keytypes |= KT_RSA1;
753 get_keytypes |= KT_DSA;
756 get_keytypes |= KT_RSA;
759 fatal("unknown key type %s", tname);
761 tname = strtok(NULL, ",");
775 if (optind == argc && !fopt_count)
778 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
780 maxfd = fdlim_get(1);
782 fatal("%s: fdlim_get: bad value", __progname);
783 if (maxfd > MAXMAXFD)
786 fatal("%s: not enough file descriptors", __progname);
787 if (maxfd > fdlim_get(0))
789 fdcon = xmalloc(maxfd * sizeof(con));
790 memset(fdcon, 0, maxfd * sizeof(con));
792 read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
793 read_wait = xmalloc(read_wait_size);
794 memset(read_wait, 0, read_wait_size);
801 for (j = 0; j < fopt_count; j++) {
802 lb = Linebuf_alloc(argv[j], error);
805 while ((line = Linebuf_getline(lb)) != NULL)
811 while (optind < argc)
812 do_host(argv[optind++]);