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1.1 markus 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"
1.17 ! deraadt 11: RCSID("$OpenBSD: ssh-keyscan.c,v 1.16 2001/02/12 22:56:10 deraadt Exp $");
1.1 markus 12:
13: #include <sys/queue.h>
14: #include <errno.h>
15:
1.5 markus 16: #include <openssl/bn.h>
1.1 markus 17:
18: #include "xmalloc.h"
19: #include "ssh.h"
1.10 markus 20: #include "ssh1.h"
1.1 markus 21: #include "key.h"
22: #include "buffer.h"
23: #include "bufaux.h"
1.11 markus 24: #include "log.h"
1.1 markus 25:
26: static int argno = 1; /* Number of argument currently being parsed */
27:
28: int family = AF_UNSPEC; /* IPv4, IPv6 or both */
29:
30: #define MAXMAXFD 256
31:
32: /* The number of seconds after which to give up on a TCP connection */
33: int timeout = 5;
34:
35: int maxfd;
36: #define maxcon (maxfd - 10)
37:
1.3 markus 38: extern char *__progname;
1.1 markus 39: fd_set read_wait;
40: int ncon;
41:
42: /*
43: * Keep a connection structure for each file descriptor. The state
44: * associated with file descriptor n is held in fdcon[n].
45: */
46: typedef struct Connection {
1.6 markus 47: u_char c_status; /* State of connection on this file desc. */
1.1 markus 48: #define CS_UNUSED 0 /* File descriptor unused */
49: #define CS_CON 1 /* Waiting to connect/read greeting */
50: #define CS_SIZE 2 /* Waiting to read initial packet size */
51: #define CS_KEYS 3 /* Waiting to read public key packet */
52: int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
53: int c_plen; /* Packet length field for ssh packet */
54: int c_len; /* Total bytes which must be read. */
55: int c_off; /* Length of data read so far. */
56: char *c_namebase; /* Address to free for c_name and c_namelist */
57: char *c_name; /* Hostname of connection for errors */
58: char *c_namelist; /* Pointer to other possible addresses */
59: char *c_output_name; /* Hostname of connection for output */
60: char *c_data; /* Data read from this fd */
61: struct timeval c_tv; /* Time at which connection gets aborted */
62: TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
63: } con;
64:
65: TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
66: con *fdcon;
67:
68: /*
69: * This is just a wrapper around fgets() to make it usable.
70: */
71:
72: /* Stress-test. Increase this later. */
73: #define LINEBUF_SIZE 16
74:
75: typedef struct {
76: char *buf;
1.6 markus 77: u_int size;
1.1 markus 78: int lineno;
79: const char *filename;
80: FILE *stream;
81: void (*errfun) (const char *,...);
82: } Linebuf;
83:
1.17 ! deraadt 84: static __inline__ Linebuf *
1.1 markus 85: Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
86: {
87: Linebuf *lb;
88:
89: if (!(lb = malloc(sizeof(*lb)))) {
90: if (errfun)
91: (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
92: return (NULL);
93: }
94: if (filename) {
95: lb->filename = filename;
96: if (!(lb->stream = fopen(filename, "r"))) {
1.9 markus 97: xfree(lb);
1.1 markus 98: if (errfun)
99: (*errfun) ("%s: %s\n", filename, strerror(errno));
100: return (NULL);
101: }
102: } else {
103: lb->filename = "(stdin)";
104: lb->stream = stdin;
105: }
106:
107: if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
108: if (errfun)
109: (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
1.9 markus 110: xfree(lb);
1.1 markus 111: return (NULL);
112: }
113: lb->errfun = errfun;
114: lb->lineno = 0;
115: return (lb);
116: }
117:
1.17 ! deraadt 118: static __inline__ void
1.1 markus 119: Linebuf_free(Linebuf * lb)
120: {
121: fclose(lb->stream);
1.9 markus 122: xfree(lb->buf);
123: xfree(lb);
1.1 markus 124: }
125:
1.17 ! deraadt 126: static __inline__ void
1.1 markus 127: Linebuf_restart(Linebuf * lb)
128: {
129: clearerr(lb->stream);
130: rewind(lb->stream);
131: lb->lineno = 0;
132: }
133:
1.17 ! deraadt 134: static __inline__ int
1.1 markus 135: Linebuf_lineno(Linebuf * lb)
136: {
137: return (lb->lineno);
138: }
139:
1.17 ! deraadt 140: static __inline__ char *
1.14 markus 141: Linebuf_getline(Linebuf * lb)
1.1 markus 142: {
143: int n = 0;
144:
145: lb->lineno++;
146: for (;;) {
147: /* Read a line */
148: if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
149: if (ferror(lb->stream) && lb->errfun)
1.17 ! deraadt 150: (*lb->errfun) ("%s: %s\n", lb->filename,
! 151: strerror(errno));
1.1 markus 152: return (NULL);
153: }
154: n = strlen(lb->buf);
155:
156: /* Return it or an error if it fits */
157: if (n > 0 && lb->buf[n - 1] == '\n') {
158: lb->buf[n - 1] = '\0';
159: return (lb->buf);
160: }
161: if (n != lb->size - 1) {
162: if (lb->errfun)
1.17 ! deraadt 163: (*lb->errfun) ("%s: skipping incomplete last line\n",
! 164: lb->filename);
1.1 markus 165: return (NULL);
166: }
167: /* Double the buffer if we need more space */
168: if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
169: if (lb->errfun)
1.17 ! deraadt 170: (*lb->errfun) ("linebuf (%s): realloc failed\n",
! 171: lb->filename);
1.1 markus 172: return (NULL);
173: }
174: }
175: }
176:
177: static int
178: fdlim_get(int hard)
179: {
180: struct rlimit rlfd;
1.17 ! deraadt 181:
1.1 markus 182: if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
183: return (-1);
184: if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
185: return 10000;
186: else
187: return hard ? rlfd.rlim_max : rlfd.rlim_cur;
188: }
189:
190: static int
191: fdlim_set(int lim)
192: {
193: struct rlimit rlfd;
194: if (lim <= 0)
195: return (-1);
196: if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
197: return (-1);
198: rlfd.rlim_cur = lim;
199: if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
200: return (-1);
201: return (0);
202: }
203:
204: /*
205: * This is an strsep function that returns a null field for adjacent
206: * separators. This is the same as the 4.4BSD strsep, but different from the
207: * one in the GNU libc.
208: */
1.17 ! deraadt 209: static __inline__ char *
1.1 markus 210: xstrsep(char **str, const char *delim)
211: {
212: char *s, *e;
213:
214: if (!**str)
215: return (NULL);
216:
217: s = *str;
218: e = s + strcspn(s, delim);
219:
220: if (*e != '\0')
221: *e++ = '\0';
222: *str = e;
223:
224: return (s);
225: }
226:
227: /*
228: * Get the next non-null token (like GNU strsep). Strsep() will return a
229: * null token for two adjacent separators, so we may have to loop.
230: */
231: char *
232: strnnsep(char **stringp, char *delim)
233: {
234: char *tok;
235:
236: do {
237: tok = xstrsep(stringp, delim);
238: } while (tok && *tok == '\0');
239: return (tok);
240: }
241:
242: void
243: keyprint(char *host, char *output_name, char *kd, int len)
244: {
245: static Key *rsa;
246: static Buffer msg;
247:
248: if (rsa == NULL) {
249: buffer_init(&msg);
250: rsa = key_new(KEY_RSA1);
251: }
252: buffer_append(&msg, kd, len);
253: buffer_consume(&msg, 8 - (len & 7)); /* padding */
254: if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
255: error("%s: invalid packet type", host);
256: buffer_clear(&msg);
257: return;
258: }
259: buffer_consume(&msg, 8); /* cookie */
260:
261: /* server key */
262: (void) buffer_get_int(&msg);
263: buffer_get_bignum(&msg, rsa->rsa->e);
264: buffer_get_bignum(&msg, rsa->rsa->n);
265:
266: /* host key */
267: (void) buffer_get_int(&msg);
268: buffer_get_bignum(&msg, rsa->rsa->e);
269: buffer_get_bignum(&msg, rsa->rsa->n);
270: buffer_clear(&msg);
271:
272: fprintf(stdout, "%s ", output_name ? output_name : host);
273: key_write(rsa, stdout);
274: fputs("\n", stdout);
275: }
276:
277: int
278: tcpconnect(char *host)
279: {
280: struct addrinfo hints, *ai, *aitop;
281: char strport[NI_MAXSERV];
282: int gaierr, s = -1;
283:
1.8 markus 284: snprintf(strport, sizeof strport, "%d", SSH_DEFAULT_PORT);
1.1 markus 285: memset(&hints, 0, sizeof(hints));
286: hints.ai_family = family;
287: hints.ai_socktype = SOCK_STREAM;
288: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
289: fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
290: for (ai = aitop; ai; ai = ai->ai_next) {
291: s = socket(ai->ai_family, SOCK_STREAM, 0);
292: if (s < 0) {
293: error("socket: %s", strerror(errno));
294: continue;
295: }
1.7 markus 296: if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
1.1 markus 297: fatal("F_SETFL: %s", strerror(errno));
298: if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
299: errno != EINPROGRESS)
300: error("connect (`%s'): %s", host, strerror(errno));
301: else
302: break;
303: close(s);
304: s = -1;
305: }
306: freeaddrinfo(aitop);
307: return s;
308: }
309:
310: int
311: conalloc(char *iname, char *oname)
312: {
313: int s;
314: char *namebase, *name, *namelist;
315:
316: namebase = namelist = xstrdup(iname);
317:
318: do {
319: name = xstrsep(&namelist, ",");
320: if (!name) {
1.9 markus 321: xfree(namebase);
1.1 markus 322: return (-1);
323: }
324: } while ((s = tcpconnect(name)) < 0);
325:
326: if (s >= maxfd)
1.4 markus 327: fatal("conalloc: fdno %d too high", s);
1.1 markus 328: if (fdcon[s].c_status)
1.4 markus 329: fatal("conalloc: attempt to reuse fdno %d", s);
1.1 markus 330:
331: fdcon[s].c_fd = s;
332: fdcon[s].c_status = CS_CON;
333: fdcon[s].c_namebase = namebase;
334: fdcon[s].c_name = name;
335: fdcon[s].c_namelist = namelist;
336: fdcon[s].c_output_name = xstrdup(oname);
337: fdcon[s].c_data = (char *) &fdcon[s].c_plen;
338: fdcon[s].c_len = 4;
339: fdcon[s].c_off = 0;
340: gettimeofday(&fdcon[s].c_tv, NULL);
341: fdcon[s].c_tv.tv_sec += timeout;
342: TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
343: FD_SET(s, &read_wait);
344: ncon++;
345: return (s);
346: }
347:
348: void
349: confree(int s)
350: {
351: close(s);
352: if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
1.4 markus 353: fatal("confree: attempt to free bad fdno %d", s);
1.9 markus 354: xfree(fdcon[s].c_namebase);
355: xfree(fdcon[s].c_output_name);
1.1 markus 356: if (fdcon[s].c_status == CS_KEYS)
1.9 markus 357: xfree(fdcon[s].c_data);
1.1 markus 358: fdcon[s].c_status = CS_UNUSED;
359: TAILQ_REMOVE(&tq, &fdcon[s], c_link);
360: FD_CLR(s, &read_wait);
361: ncon--;
362: }
363:
364: void
365: contouch(int s)
366: {
367: TAILQ_REMOVE(&tq, &fdcon[s], c_link);
368: gettimeofday(&fdcon[s].c_tv, NULL);
369: fdcon[s].c_tv.tv_sec += timeout;
370: TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
371: }
372:
373: int
374: conrecycle(int s)
375: {
376: int ret;
377: con *c = &fdcon[s];
378: char *iname, *oname;
379:
380: iname = xstrdup(c->c_namelist);
1.9 markus 381: oname = xstrdup(c->c_output_name);
1.1 markus 382: confree(s);
383: ret = conalloc(iname, oname);
1.9 markus 384: xfree(iname);
385: xfree(oname);
1.1 markus 386: return (ret);
387: }
388:
389: void
390: congreet(int s)
391: {
392: char buf[80];
393: int n;
394: con *c = &fdcon[s];
395:
396: n = read(s, buf, sizeof(buf));
397: if (n < 0) {
398: if (errno != ECONNREFUSED)
399: error("read (%s): %s", c->c_name, strerror(errno));
400: conrecycle(s);
401: return;
402: }
403: if (buf[n - 1] != '\n') {
404: error("%s: bad greeting", c->c_name);
405: confree(s);
406: return;
407: }
408: buf[n - 1] = '\0';
409: fprintf(stderr, "# %s %s\n", c->c_name, buf);
410: n = snprintf(buf, sizeof buf, "SSH-1.5-OpenSSH-keyscan\r\n");
411: if (write(s, buf, n) != n) {
412: error("write (%s): %s", c->c_name, strerror(errno));
413: confree(s);
414: return;
415: }
416: c->c_status = CS_SIZE;
417: contouch(s);
418: }
419:
420: void
421: conread(int s)
422: {
423: int n;
424: con *c = &fdcon[s];
425:
426: if (c->c_status == CS_CON) {
427: congreet(s);
428: return;
429: }
430: n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
431: if (n < 0) {
432: error("read (%s): %s", c->c_name, strerror(errno));
433: confree(s);
434: return;
435: }
436: c->c_off += n;
437:
438: if (c->c_off == c->c_len)
439: switch (c->c_status) {
440: case CS_SIZE:
441: c->c_plen = htonl(c->c_plen);
442: c->c_len = c->c_plen + 8 - (c->c_plen & 7);
443: c->c_off = 0;
444: c->c_data = xmalloc(c->c_len);
445: c->c_status = CS_KEYS;
446: break;
447: case CS_KEYS:
448: keyprint(c->c_name, c->c_output_name, c->c_data, c->c_plen);
449: confree(s);
450: return;
451: break;
452: default:
1.4 markus 453: fatal("conread: invalid status %d", c->c_status);
1.1 markus 454: break;
455: }
456:
457: contouch(s);
458: }
459:
460: void
461: conloop(void)
462: {
463: fd_set r, e;
464: struct timeval seltime, now;
465: int i;
466: con *c;
467:
468: gettimeofday(&now, NULL);
469: c = tq.tqh_first;
470:
471: if (c &&
472: (c->c_tv.tv_sec > now.tv_sec ||
473: (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
474: seltime = c->c_tv;
475: seltime.tv_sec -= now.tv_sec;
476: seltime.tv_usec -= now.tv_usec;
1.13 itojun 477: if (seltime.tv_usec < 0) {
1.1 markus 478: seltime.tv_usec += 1000000;
479: seltime.tv_sec--;
480: }
481: } else
482: seltime.tv_sec = seltime.tv_usec = 0;
483:
484: r = e = read_wait;
1.16 deraadt 485: while (select(maxfd, &r, NULL, &e, &seltime) == -1 &&
486: (errno == EAGAIN || errno == EINTR))
487: ;
488:
1.1 markus 489: for (i = 0; i < maxfd; i++)
490: if (FD_ISSET(i, &e)) {
491: error("%s: exception!", fdcon[i].c_name);
492: confree(i);
493: } else if (FD_ISSET(i, &r))
494: conread(i);
495:
496: c = tq.tqh_first;
497: while (c &&
498: (c->c_tv.tv_sec < now.tv_sec ||
1.12 stevesk 499: (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
1.1 markus 500: int s = c->c_fd;
501: c = c->c_link.tqe_next;
502: conrecycle(s);
503: }
504: }
505:
506: char *
507: nexthost(int argc, char **argv)
508: {
509: static Linebuf *lb;
510:
511: for (;;) {
512: if (!lb) {
513: if (argno >= argc)
514: return (NULL);
515: if (argv[argno][0] != '-')
516: return (argv[argno++]);
517: if (!strcmp(argv[argno], "--")) {
518: if (++argno >= argc)
519: return (NULL);
520: return (argv[argno++]);
521: } else if (!strncmp(argv[argno], "-f", 2)) {
522: char *fname;
523: if (argv[argno][2])
524: fname = &argv[argno++][2];
525: else if (++argno >= argc) {
526: error("missing filename for `-f'");
527: return (NULL);
528: } else
529: fname = argv[argno++];
530: if (!strcmp(fname, "-"))
531: fname = NULL;
1.2 markus 532: lb = Linebuf_alloc(fname, error);
1.1 markus 533: } else
534: error("ignoring invalid/misplaced option `%s'", argv[argno++]);
535: } else {
536: char *line;
1.14 markus 537: line = Linebuf_getline(lb);
1.1 markus 538: if (line)
539: return (line);
540: Linebuf_free(lb);
541: lb = NULL;
542: }
543: }
544: }
545:
546: static void
547: usage(void)
548: {
1.4 markus 549: fatal("usage: %s [-t timeout] { [--] host | -f file } ...", __progname);
1.1 markus 550: return;
551: }
552:
553: int
554: main(int argc, char **argv)
555: {
556: char *host = NULL;
557:
558: TAILQ_INIT(&tq);
559:
560: if (argc <= argno)
561: usage();
562:
563: if (argv[1][0] == '-' && argv[1][1] == 't') {
564: argno++;
565: if (argv[1][2])
566: timeout = atoi(&argv[1][2]);
567: else {
568: if (argno >= argc)
569: usage();
570: timeout = atoi(argv[argno++]);
571: }
572: if (timeout <= 0)
573: usage();
574: }
575: if (argc <= argno)
576: usage();
577:
578: maxfd = fdlim_get(1);
579: if (maxfd < 0)
1.4 markus 580: fatal("%s: fdlim_get: bad value", __progname);
1.1 markus 581: if (maxfd > MAXMAXFD)
582: maxfd = MAXMAXFD;
583: if (maxcon <= 0)
1.4 markus 584: fatal("%s: not enough file descriptors", __progname);
1.1 markus 585: if (maxfd > fdlim_get(0))
586: fdlim_set(maxfd);
587: fdcon = xmalloc(maxfd * sizeof(con));
1.15 itojun 588: memset(fdcon, 0, maxfd * sizeof(con));
1.1 markus 589:
590: do {
591: while (ncon < maxcon) {
592: char *name;
593:
594: host = nexthost(argc, argv);
595: if (host == NULL)
596: break;
597: name = strnnsep(&host, " \t\n");
598: conalloc(name, *host ? host : name);
599: }
600: conloop();
601: } while (host);
602: while (ncon > 0)
603: conloop();
604:
605: return (0);
606: }