]> andersk Git - openssh.git/blame - ssh-keyscan.c
- deraadt@cvs.openbsd.org 2001/02/21 07:37:04
[openssh.git] / ssh-keyscan.c
CommitLineData
f6fdbddf 1/*
2 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
3 *
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 (for instance by leaving this copyright notice
7 * intact).
8 */
9
10#include "includes.h"
778f6940 11RCSID("$OpenBSD: ssh-keyscan.c,v 1.17 2001/02/21 07:37:04 deraadt Exp $");
f6fdbddf 12
b705bea0 13#if defined(HAVE_SYS_QUEUE_H) && !defined(HAVE_BOGUS_SYS_QUEUE_H)
f6fdbddf 14#include <sys/queue.h>
bf5f69f7 15#else
bf3db92d 16#include "fake-queue.h"
bf5f69f7 17#endif
f6fdbddf 18#include <errno.h>
19
20#include <openssl/bn.h>
f6fdbddf 21
22#include "xmalloc.h"
23#include "ssh.h"
42f11eb2 24#include "ssh1.h"
f6fdbddf 25#include "key.h"
26#include "buffer.h"
27#include "bufaux.h"
42f11eb2 28#include "log.h"
f6fdbddf 29
30static int argno = 1; /* Number of argument currently being parsed */
31
32int family = AF_UNSPEC; /* IPv4, IPv6 or both */
33
f6fdbddf 34#define MAXMAXFD 256
35
36/* The number of seconds after which to give up on a TCP connection */
37int timeout = 5;
38
39int maxfd;
40#define maxcon (maxfd - 10)
41
1fe6a48f 42#ifdef HAVE___PROGNAME
43extern char *__progname;
44#else
45char *__progname;
46#endif
f6fdbddf 47fd_set read_wait;
48int ncon;
49
50/*
51 * Keep a connection structure for each file descriptor. The state
52 * associated with file descriptor n is held in fdcon[n].
53 */
54typedef struct Connection {
1e3b8b07 55 u_char c_status; /* State of connection on this file desc. */
f6fdbddf 56#define CS_UNUSED 0 /* File descriptor unused */
57#define CS_CON 1 /* Waiting to connect/read greeting */
58#define CS_SIZE 2 /* Waiting to read initial packet size */
59#define CS_KEYS 3 /* Waiting to read public key packet */
60 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
61 int c_plen; /* Packet length field for ssh packet */
62 int c_len; /* Total bytes which must be read. */
63 int c_off; /* Length of data read so far. */
64 char *c_namebase; /* Address to free for c_name and c_namelist */
65 char *c_name; /* Hostname of connection for errors */
66 char *c_namelist; /* Pointer to other possible addresses */
67 char *c_output_name; /* Hostname of connection for output */
68 char *c_data; /* Data read from this fd */
69 struct timeval c_tv; /* Time at which connection gets aborted */
70 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
71} con;
72
73TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
74con *fdcon;
75
76/*
77 * This is just a wrapper around fgets() to make it usable.
78 */
79
80/* Stress-test. Increase this later. */
81#define LINEBUF_SIZE 16
82
83typedef struct {
84 char *buf;
1e3b8b07 85 u_int size;
f6fdbddf 86 int lineno;
87 const char *filename;
88 FILE *stream;
89 void (*errfun) (const char *,...);
90} Linebuf;
91
778f6940 92static __inline__ Linebuf *
f6fdbddf 93Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
94{
95 Linebuf *lb;
96
97 if (!(lb = malloc(sizeof(*lb)))) {
98 if (errfun)
99 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
100 return (NULL);
101 }
102 if (filename) {
103 lb->filename = filename;
104 if (!(lb->stream = fopen(filename, "r"))) {
b5c334cc 105 xfree(lb);
f6fdbddf 106 if (errfun)
107 (*errfun) ("%s: %s\n", filename, strerror(errno));
108 return (NULL);
109 }
110 } else {
111 lb->filename = "(stdin)";
112 lb->stream = stdin;
113 }
114
115 if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
116 if (errfun)
117 (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
b5c334cc 118 xfree(lb);
f6fdbddf 119 return (NULL);
120 }
121 lb->errfun = errfun;
122 lb->lineno = 0;
123 return (lb);
124}
125
778f6940 126static __inline__ void
f6fdbddf 127Linebuf_free(Linebuf * lb)
128{
129 fclose(lb->stream);
b5c334cc 130 xfree(lb->buf);
131 xfree(lb);
f6fdbddf 132}
133
778f6940 134static __inline__ void
f6fdbddf 135Linebuf_restart(Linebuf * lb)
136{
137 clearerr(lb->stream);
138 rewind(lb->stream);
139 lb->lineno = 0;
140}
141
778f6940 142static __inline__ int
f6fdbddf 143Linebuf_lineno(Linebuf * lb)
144{
145 return (lb->lineno);
146}
147
778f6940 148static __inline__ char *
5be2ec5e 149Linebuf_getline(Linebuf * lb)
f6fdbddf 150{
151 int n = 0;
152
153 lb->lineno++;
154 for (;;) {
155 /* Read a line */
156 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
157 if (ferror(lb->stream) && lb->errfun)
778f6940 158 (*lb->errfun) ("%s: %s\n", lb->filename,
159 strerror(errno));
f6fdbddf 160 return (NULL);
161 }
162 n = strlen(lb->buf);
163
164 /* Return it or an error if it fits */
165 if (n > 0 && lb->buf[n - 1] == '\n') {
166 lb->buf[n - 1] = '\0';
167 return (lb->buf);
168 }
169 if (n != lb->size - 1) {
170 if (lb->errfun)
778f6940 171 (*lb->errfun) ("%s: skipping incomplete last line\n",
172 lb->filename);
f6fdbddf 173 return (NULL);
174 }
175 /* Double the buffer if we need more space */
176 if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
177 if (lb->errfun)
778f6940 178 (*lb->errfun) ("linebuf (%s): realloc failed\n",
179 lb->filename);
f6fdbddf 180 return (NULL);
181 }
182 }
183}
184
185static int
186fdlim_get(int hard)
187{
f318b98b 188#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
f6fdbddf 189 struct rlimit rlfd;
778f6940 190
f6fdbddf 191 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
192 return (-1);
193 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
194 return 10000;
195 else
196 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
b03bd394 197#elif defined (HAVE_SYSCONF)
198 return sysconf (_SC_OPEN_MAX);
199#else
200 return 10000;
201#endif
f6fdbddf 202}
203
204static int
205fdlim_set(int lim)
206{
f318b98b 207#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
f6fdbddf 208 struct rlimit rlfd;
b03bd394 209#endif
f6fdbddf 210 if (lim <= 0)
211 return (-1);
f318b98b 212#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
f6fdbddf 213 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
214 return (-1);
215 rlfd.rlim_cur = lim;
216 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
217 return (-1);
b03bd394 218#elif defined (HAVE_SETDTABLESIZE)
b705bea0 219 setdtablesize(lim);
b03bd394 220#endif
f6fdbddf 221 return (0);
222}
223
224/*
225 * This is an strsep function that returns a null field for adjacent
226 * separators. This is the same as the 4.4BSD strsep, but different from the
227 * one in the GNU libc.
228 */
778f6940 229static __inline__ char *
f6fdbddf 230xstrsep(char **str, const char *delim)
231{
232 char *s, *e;
233
234 if (!**str)
235 return (NULL);
236
237 s = *str;
238 e = s + strcspn(s, delim);
239
240 if (*e != '\0')
241 *e++ = '\0';
242 *str = e;
243
244 return (s);
245}
246
247/*
248 * Get the next non-null token (like GNU strsep). Strsep() will return a
249 * null token for two adjacent separators, so we may have to loop.
250 */
251char *
252strnnsep(char **stringp, char *delim)
253{
254 char *tok;
255
256 do {
257 tok = xstrsep(stringp, delim);
258 } while (tok && *tok == '\0');
259 return (tok);
260}
261
262void
263keyprint(char *host, char *output_name, char *kd, int len)
264{
265 static Key *rsa;
266 static Buffer msg;
267
268 if (rsa == NULL) {
269 buffer_init(&msg);
270 rsa = key_new(KEY_RSA1);
271 }
272 buffer_append(&msg, kd, len);
273 buffer_consume(&msg, 8 - (len & 7)); /* padding */
274 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
275 error("%s: invalid packet type", host);
276 buffer_clear(&msg);
277 return;
278 }
279 buffer_consume(&msg, 8); /* cookie */
280
281 /* server key */
282 (void) buffer_get_int(&msg);
283 buffer_get_bignum(&msg, rsa->rsa->e);
284 buffer_get_bignum(&msg, rsa->rsa->n);
285
286 /* host key */
287 (void) buffer_get_int(&msg);
288 buffer_get_bignum(&msg, rsa->rsa->e);
289 buffer_get_bignum(&msg, rsa->rsa->n);
290 buffer_clear(&msg);
291
292 fprintf(stdout, "%s ", output_name ? output_name : host);
293 key_write(rsa, stdout);
294 fputs("\n", stdout);
295}
296
297int
298tcpconnect(char *host)
299{
300 struct addrinfo hints, *ai, *aitop;
301 char strport[NI_MAXSERV];
302 int gaierr, s = -1;
303
b5c334cc 304 snprintf(strport, sizeof strport, "%d", SSH_DEFAULT_PORT);
f6fdbddf 305 memset(&hints, 0, sizeof(hints));
306 hints.ai_family = family;
307 hints.ai_socktype = SOCK_STREAM;
308 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
309 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
310 for (ai = aitop; ai; ai = ai->ai_next) {
311 s = socket(ai->ai_family, SOCK_STREAM, 0);
312 if (s < 0) {
313 error("socket: %s", strerror(errno));
314 continue;
315 }
eea39c02 316 if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
f6fdbddf 317 fatal("F_SETFL: %s", strerror(errno));
318 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
319 errno != EINPROGRESS)
320 error("connect (`%s'): %s", host, strerror(errno));
321 else
322 break;
323 close(s);
324 s = -1;
325 }
326 freeaddrinfo(aitop);
327 return s;
328}
329
330int
331conalloc(char *iname, char *oname)
332{
333 int s;
334 char *namebase, *name, *namelist;
335
336 namebase = namelist = xstrdup(iname);
337
338 do {
339 name = xstrsep(&namelist, ",");
340 if (!name) {
b5c334cc 341 xfree(namebase);
f6fdbddf 342 return (-1);
343 }
344 } while ((s = tcpconnect(name)) < 0);
345
346 if (s >= maxfd)
227e8e86 347 fatal("conalloc: fdno %d too high", s);
f6fdbddf 348 if (fdcon[s].c_status)
227e8e86 349 fatal("conalloc: attempt to reuse fdno %d", s);
f6fdbddf 350
351 fdcon[s].c_fd = 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;
358 fdcon[s].c_len = 4;
359 fdcon[s].c_off = 0;
360 gettimeofday(&fdcon[s].c_tv, NULL);
361 fdcon[s].c_tv.tv_sec += timeout;
362 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
363 FD_SET(s, &read_wait);
364 ncon++;
365 return (s);
366}
367
368void
369confree(int s)
370{
371 close(s);
372 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
227e8e86 373 fatal("confree: attempt to free bad fdno %d", s);
b5c334cc 374 xfree(fdcon[s].c_namebase);
375 xfree(fdcon[s].c_output_name);
f6fdbddf 376 if (fdcon[s].c_status == CS_KEYS)
b5c334cc 377 xfree(fdcon[s].c_data);
f6fdbddf 378 fdcon[s].c_status = CS_UNUSED;
379 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
380 FD_CLR(s, &read_wait);
381 ncon--;
382}
383
384void
385contouch(int s)
386{
387 TAILQ_REMOVE(&tq, &fdcon[s], c_link);
388 gettimeofday(&fdcon[s].c_tv, NULL);
389 fdcon[s].c_tv.tv_sec += timeout;
390 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
391}
392
393int
394conrecycle(int s)
395{
396 int ret;
397 con *c = &fdcon[s];
398 char *iname, *oname;
399
400 iname = xstrdup(c->c_namelist);
b5c334cc 401 oname = xstrdup(c->c_output_name);
f6fdbddf 402 confree(s);
403 ret = conalloc(iname, oname);
b5c334cc 404 xfree(iname);
405 xfree(oname);
f6fdbddf 406 return (ret);
407}
408
409void
410congreet(int s)
411{
412 char buf[80];
413 int n;
414 con *c = &fdcon[s];
415
416 n = read(s, buf, sizeof(buf));
417 if (n < 0) {
418 if (errno != ECONNREFUSED)
419 error("read (%s): %s", c->c_name, strerror(errno));
420 conrecycle(s);
421 return;
422 }
423 if (buf[n - 1] != '\n') {
424 error("%s: bad greeting", c->c_name);
425 confree(s);
426 return;
427 }
428 buf[n - 1] = '\0';
429 fprintf(stderr, "# %s %s\n", c->c_name, buf);
430 n = snprintf(buf, sizeof buf, "SSH-1.5-OpenSSH-keyscan\r\n");
431 if (write(s, buf, n) != n) {
432 error("write (%s): %s", c->c_name, strerror(errno));
433 confree(s);
434 return;
435 }
436 c->c_status = CS_SIZE;
437 contouch(s);
438}
439
440void
441conread(int s)
442{
443 int n;
444 con *c = &fdcon[s];
445
446 if (c->c_status == CS_CON) {
447 congreet(s);
448 return;
449 }
450 n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
451 if (n < 0) {
452 error("read (%s): %s", c->c_name, strerror(errno));
453 confree(s);
454 return;
455 }
456 c->c_off += n;
457
458 if (c->c_off == c->c_len)
459 switch (c->c_status) {
460 case CS_SIZE:
461 c->c_plen = htonl(c->c_plen);
462 c->c_len = c->c_plen + 8 - (c->c_plen & 7);
463 c->c_off = 0;
464 c->c_data = xmalloc(c->c_len);
465 c->c_status = CS_KEYS;
466 break;
467 case CS_KEYS:
468 keyprint(c->c_name, c->c_output_name, c->c_data, c->c_plen);
469 confree(s);
470 return;
471 break;
472 default:
227e8e86 473 fatal("conread: invalid status %d", c->c_status);
f6fdbddf 474 break;
475 }
476
477 contouch(s);
478}
479
480void
481conloop(void)
482{
483 fd_set r, e;
484 struct timeval seltime, now;
485 int i;
486 con *c;
487
488 gettimeofday(&now, NULL);
489 c = tq.tqh_first;
490
491 if (c &&
492 (c->c_tv.tv_sec > now.tv_sec ||
493 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
494 seltime = c->c_tv;
495 seltime.tv_sec -= now.tv_sec;
496 seltime.tv_usec -= now.tv_usec;
5be2ec5e 497 if (seltime.tv_usec < 0) {
f6fdbddf 498 seltime.tv_usec += 1000000;
499 seltime.tv_sec--;
500 }
501 } else
502 seltime.tv_sec = seltime.tv_usec = 0;
503
504 r = e = read_wait;
fd193ca4 505 while (select(maxfd, &r, NULL, &e, &seltime) == -1 &&
506 (errno == EAGAIN || errno == EINTR))
507 ;
508
f6fdbddf 509 for (i = 0; i < maxfd; i++)
510 if (FD_ISSET(i, &e)) {
511 error("%s: exception!", fdcon[i].c_name);
512 confree(i);
513 } else if (FD_ISSET(i, &r))
514 conread(i);
515
516 c = tq.tqh_first;
517 while (c &&
518 (c->c_tv.tv_sec < now.tv_sec ||
2b87da3b 519 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
f6fdbddf 520 int s = c->c_fd;
521 c = c->c_link.tqe_next;
522 conrecycle(s);
523 }
524}
525
526char *
527nexthost(int argc, char **argv)
528{
529 static Linebuf *lb;
530
531 for (;;) {
532 if (!lb) {
533 if (argno >= argc)
534 return (NULL);
535 if (argv[argno][0] != '-')
536 return (argv[argno++]);
537 if (!strcmp(argv[argno], "--")) {
538 if (++argno >= argc)
539 return (NULL);
540 return (argv[argno++]);
541 } else if (!strncmp(argv[argno], "-f", 2)) {
542 char *fname;
543 if (argv[argno][2])
544 fname = &argv[argno++][2];
545 else if (++argno >= argc) {
546 error("missing filename for `-f'");
547 return (NULL);
548 } else
549 fname = argv[argno++];
550 if (!strcmp(fname, "-"))
551 fname = NULL;
f20255cb 552 lb = Linebuf_alloc(fname, error);
f6fdbddf 553 } else
554 error("ignoring invalid/misplaced option `%s'", argv[argno++]);
555 } else {
556 char *line;
5be2ec5e 557 line = Linebuf_getline(lb);
f6fdbddf 558 if (line)
559 return (line);
560 Linebuf_free(lb);
561 lb = NULL;
562 }
563 }
564}
565
566static void
567usage(void)
568{
227e8e86 569 fatal("usage: %s [-t timeout] { [--] host | -f file } ...", __progname);
f6fdbddf 570 return;
571}
572
573int
574main(int argc, char **argv)
575{
576 char *host = NULL;
577
1fe6a48f 578 __progname = get_progname(argv[0]);
f6fdbddf 579 TAILQ_INIT(&tq);
580
f6fdbddf 581 if (argc <= argno)
582 usage();
583
584 if (argv[1][0] == '-' && argv[1][1] == 't') {
585 argno++;
586 if (argv[1][2])
587 timeout = atoi(&argv[1][2]);
588 else {
589 if (argno >= argc)
590 usage();
591 timeout = atoi(argv[argno++]);
592 }
593 if (timeout <= 0)
594 usage();
595 }
596 if (argc <= argno)
597 usage();
598
599 maxfd = fdlim_get(1);
600 if (maxfd < 0)
227e8e86 601 fatal("%s: fdlim_get: bad value", __progname);
f6fdbddf 602 if (maxfd > MAXMAXFD)
603 maxfd = MAXMAXFD;
604 if (maxcon <= 0)
227e8e86 605 fatal("%s: not enough file descriptors", __progname);
f6fdbddf 606 if (maxfd > fdlim_get(0))
607 fdlim_set(maxfd);
608 fdcon = xmalloc(maxfd * sizeof(con));
5be2ec5e 609 memset(fdcon, 0, maxfd * sizeof(con));
f6fdbddf 610
611 do {
612 while (ncon < maxcon) {
613 char *name;
614
615 host = nexthost(argc, argv);
616 if (host == NULL)
617 break;
618 name = strnnsep(&host, " \t\n");
619 conalloc(name, *host ? host : name);
620 }
621 conloop();
622 } while (host);
623 while (ncon > 0)
624 conloop();
625
626 return (0);
627}
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