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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"
1.6 ! markus 11: RCSID("$OpenBSD: ssh-keyscan.c,v 1.5 2000/12/19 22:48:08 markus Exp $");
1.1 markus 12:
13: #include <sys/queue.h>
14: #include <errno.h>
15:
1.5 markus 16: #include <openssl/bn.h>
17: #include <openssl/rsa.h>
18: #include <openssl/dsa.h>
1.1 markus 19:
20: #include "xmalloc.h"
21: #include "ssh.h"
22: #include "key.h"
23: #include "buffer.h"
24: #include "bufaux.h"
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 PORT 22
31: #define MAXMAXFD 256
32:
33: /* The number of seconds after which to give up on a TCP connection */
34: int timeout = 5;
35:
36: int maxfd;
37: #define maxcon (maxfd - 10)
38:
1.3 markus 39: extern char *__progname;
1.1 markus 40: fd_set read_wait;
41: int ncon;
42:
43: /*
44: * Keep a connection structure for each file descriptor. The state
45: * associated with file descriptor n is held in fdcon[n].
46: */
47: typedef struct Connection {
1.6 ! markus 48: u_char c_status; /* State of connection on this file desc. */
1.1 markus 49: #define CS_UNUSED 0 /* File descriptor unused */
50: #define CS_CON 1 /* Waiting to connect/read greeting */
51: #define CS_SIZE 2 /* Waiting to read initial packet size */
52: #define CS_KEYS 3 /* Waiting to read public key packet */
53: int c_fd; /* Quick lookup: c->c_fd == c - fdcon */
54: int c_plen; /* Packet length field for ssh packet */
55: int c_len; /* Total bytes which must be read. */
56: int c_off; /* Length of data read so far. */
57: char *c_namebase; /* Address to free for c_name and c_namelist */
58: char *c_name; /* Hostname of connection for errors */
59: char *c_namelist; /* Pointer to other possible addresses */
60: char *c_output_name; /* Hostname of connection for output */
61: char *c_data; /* Data read from this fd */
62: struct timeval c_tv; /* Time at which connection gets aborted */
63: TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
64: } con;
65:
66: TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
67: con *fdcon;
68:
69: /*
70: * This is just a wrapper around fgets() to make it usable.
71: */
72:
73: /* Stress-test. Increase this later. */
74: #define LINEBUF_SIZE 16
75:
76: typedef struct {
77: char *buf;
1.6 ! markus 78: u_int size;
1.1 markus 79: int lineno;
80: const char *filename;
81: FILE *stream;
82: void (*errfun) (const char *,...);
83: } Linebuf;
84:
85: static inline Linebuf *
86: Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
87: {
88: Linebuf *lb;
89:
90: if (!(lb = malloc(sizeof(*lb)))) {
91: if (errfun)
92: (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
93: return (NULL);
94: }
95: if (filename) {
96: lb->filename = filename;
97: if (!(lb->stream = fopen(filename, "r"))) {
98: free(lb);
99: if (errfun)
100: (*errfun) ("%s: %s\n", filename, strerror(errno));
101: return (NULL);
102: }
103: } else {
104: lb->filename = "(stdin)";
105: lb->stream = stdin;
106: }
107:
108: if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
109: if (errfun)
110: (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
111: free(lb);
112: return (NULL);
113: }
114: lb->errfun = errfun;
115: lb->lineno = 0;
116: return (lb);
117: }
118:
119: static inline void
120: Linebuf_free(Linebuf * lb)
121: {
122: fclose(lb->stream);
123: free(lb->buf);
124: free(lb);
125: }
126:
127: static inline void
128: Linebuf_restart(Linebuf * lb)
129: {
130: clearerr(lb->stream);
131: rewind(lb->stream);
132: lb->lineno = 0;
133: }
134:
135: static inline int
136: Linebuf_lineno(Linebuf * lb)
137: {
138: return (lb->lineno);
139: }
140:
141: static inline char *
142: getline(Linebuf * lb)
143: {
144: int n = 0;
145:
146: lb->lineno++;
147: for (;;) {
148: /* Read a line */
149: if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
150: if (ferror(lb->stream) && lb->errfun)
151: (*lb->errfun) ("%s: %s\n", lb->filename, strerror(errno));
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)
163: (*lb->errfun) ("%s: skipping incomplete last line\n", lb->filename);
164: return (NULL);
165: }
166: /* Double the buffer if we need more space */
167: if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
168: if (lb->errfun)
169: (*lb->errfun) ("linebuf (%s): realloc failed\n", lb->filename);
170: return (NULL);
171: }
172: }
173: }
174:
175: static int
176: fdlim_get(int hard)
177: {
178: struct rlimit rlfd;
179: if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
180: return (-1);
181: if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
182: return 10000;
183: else
184: return hard ? rlfd.rlim_max : rlfd.rlim_cur;
185: }
186:
187: static int
188: fdlim_set(int lim)
189: {
190: struct rlimit rlfd;
191: if (lim <= 0)
192: return (-1);
193: if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
194: return (-1);
195: rlfd.rlim_cur = lim;
196: if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
197: return (-1);
198: return (0);
199: }
200:
201: /*
202: * This is an strsep function that returns a null field for adjacent
203: * separators. This is the same as the 4.4BSD strsep, but different from the
204: * one in the GNU libc.
205: */
206: inline char *
207: xstrsep(char **str, const char *delim)
208: {
209: char *s, *e;
210:
211: if (!**str)
212: return (NULL);
213:
214: s = *str;
215: e = s + strcspn(s, delim);
216:
217: if (*e != '\0')
218: *e++ = '\0';
219: *str = e;
220:
221: return (s);
222: }
223:
224: /*
225: * Get the next non-null token (like GNU strsep). Strsep() will return a
226: * null token for two adjacent separators, so we may have to loop.
227: */
228: char *
229: strnnsep(char **stringp, char *delim)
230: {
231: char *tok;
232:
233: do {
234: tok = xstrsep(stringp, delim);
235: } while (tok && *tok == '\0');
236: return (tok);
237: }
238:
239: void
240: keyprint(char *host, char *output_name, char *kd, int len)
241: {
242: static Key *rsa;
243: static Buffer msg;
244:
245: if (rsa == NULL) {
246: buffer_init(&msg);
247: rsa = key_new(KEY_RSA1);
248: }
249: buffer_append(&msg, kd, len);
250: buffer_consume(&msg, 8 - (len & 7)); /* padding */
251: if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
252: error("%s: invalid packet type", host);
253: buffer_clear(&msg);
254: return;
255: }
256: buffer_consume(&msg, 8); /* cookie */
257:
258: /* server key */
259: (void) buffer_get_int(&msg);
260: buffer_get_bignum(&msg, rsa->rsa->e);
261: buffer_get_bignum(&msg, rsa->rsa->n);
262:
263: /* host key */
264: (void) buffer_get_int(&msg);
265: buffer_get_bignum(&msg, rsa->rsa->e);
266: buffer_get_bignum(&msg, rsa->rsa->n);
267: buffer_clear(&msg);
268:
269: fprintf(stdout, "%s ", output_name ? output_name : host);
270: key_write(rsa, stdout);
271: fputs("\n", stdout);
272: }
273:
274: int
275: tcpconnect(char *host)
276: {
277: struct addrinfo hints, *ai, *aitop;
278: char strport[NI_MAXSERV];
279: int gaierr, s = -1;
280:
281: snprintf(strport, sizeof strport, "%d", PORT);
282: memset(&hints, 0, sizeof(hints));
283: hints.ai_family = family;
284: hints.ai_socktype = SOCK_STREAM;
285: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
286: fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
287: for (ai = aitop; ai; ai = ai->ai_next) {
288: s = socket(ai->ai_family, SOCK_STREAM, 0);
289: if (s < 0) {
290: error("socket: %s", strerror(errno));
291: continue;
292: }
293: if (fcntl(s, F_SETFL, O_NDELAY) < 0)
294: fatal("F_SETFL: %s", strerror(errno));
295: if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
296: errno != EINPROGRESS)
297: error("connect (`%s'): %s", host, strerror(errno));
298: else
299: break;
300: close(s);
301: s = -1;
302: }
303: freeaddrinfo(aitop);
304: return s;
305: }
306:
307: int
308: conalloc(char *iname, char *oname)
309: {
310: int s;
311: char *namebase, *name, *namelist;
312:
313: namebase = namelist = xstrdup(iname);
314:
315: do {
316: name = xstrsep(&namelist, ",");
317: if (!name) {
318: free(namebase);
319: return (-1);
320: }
321: } while ((s = tcpconnect(name)) < 0);
322:
323: if (s >= maxfd)
1.4 markus 324: fatal("conalloc: fdno %d too high", s);
1.1 markus 325: if (fdcon[s].c_status)
1.4 markus 326: fatal("conalloc: attempt to reuse fdno %d", s);
1.1 markus 327:
328: fdcon[s].c_fd = s;
329: fdcon[s].c_status = CS_CON;
330: fdcon[s].c_namebase = namebase;
331: fdcon[s].c_name = name;
332: fdcon[s].c_namelist = namelist;
333: fdcon[s].c_output_name = xstrdup(oname);
334: fdcon[s].c_data = (char *) &fdcon[s].c_plen;
335: fdcon[s].c_len = 4;
336: fdcon[s].c_off = 0;
337: gettimeofday(&fdcon[s].c_tv, NULL);
338: fdcon[s].c_tv.tv_sec += timeout;
339: TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
340: FD_SET(s, &read_wait);
341: ncon++;
342: return (s);
343: }
344:
345: void
346: confree(int s)
347: {
348: close(s);
349: if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
1.4 markus 350: fatal("confree: attempt to free bad fdno %d", s);
1.1 markus 351: free(fdcon[s].c_namebase);
352: free(fdcon[s].c_output_name);
353: if (fdcon[s].c_status == CS_KEYS)
354: free(fdcon[s].c_data);
355: fdcon[s].c_status = CS_UNUSED;
356: TAILQ_REMOVE(&tq, &fdcon[s], c_link);
357: FD_CLR(s, &read_wait);
358: ncon--;
359: }
360:
361: void
362: contouch(int s)
363: {
364: TAILQ_REMOVE(&tq, &fdcon[s], c_link);
365: gettimeofday(&fdcon[s].c_tv, NULL);
366: fdcon[s].c_tv.tv_sec += timeout;
367: TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
368: }
369:
370: int
371: conrecycle(int s)
372: {
373: int ret;
374: con *c = &fdcon[s];
375: char *iname, *oname;
376:
377: iname = xstrdup(c->c_namelist);
378: oname = c->c_output_name;
379: c->c_output_name = NULL;/* prevent it from being freed */
380: confree(s);
381: ret = conalloc(iname, oname);
382: free(iname);
383: return (ret);
384: }
385:
386: void
387: congreet(int s)
388: {
389: char buf[80];
390: int n;
391: con *c = &fdcon[s];
392:
393: n = read(s, buf, sizeof(buf));
394: if (n < 0) {
395: if (errno != ECONNREFUSED)
396: error("read (%s): %s", c->c_name, strerror(errno));
397: conrecycle(s);
398: return;
399: }
400: if (buf[n - 1] != '\n') {
401: error("%s: bad greeting", c->c_name);
402: confree(s);
403: return;
404: }
405: buf[n - 1] = '\0';
406: fprintf(stderr, "# %s %s\n", c->c_name, buf);
407: n = snprintf(buf, sizeof buf, "SSH-1.5-OpenSSH-keyscan\r\n");
408: if (write(s, buf, n) != n) {
409: error("write (%s): %s", c->c_name, strerror(errno));
410: confree(s);
411: return;
412: }
413: c->c_status = CS_SIZE;
414: contouch(s);
415: }
416:
417: void
418: conread(int s)
419: {
420: int n;
421: con *c = &fdcon[s];
422:
423: if (c->c_status == CS_CON) {
424: congreet(s);
425: return;
426: }
427: n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
428: if (n < 0) {
429: error("read (%s): %s", c->c_name, strerror(errno));
430: confree(s);
431: return;
432: }
433: c->c_off += n;
434:
435: if (c->c_off == c->c_len)
436: switch (c->c_status) {
437: case CS_SIZE:
438: c->c_plen = htonl(c->c_plen);
439: c->c_len = c->c_plen + 8 - (c->c_plen & 7);
440: c->c_off = 0;
441: c->c_data = xmalloc(c->c_len);
442: c->c_status = CS_KEYS;
443: break;
444: case CS_KEYS:
445: keyprint(c->c_name, c->c_output_name, c->c_data, c->c_plen);
446: confree(s);
447: return;
448: break;
449: default:
1.4 markus 450: fatal("conread: invalid status %d", c->c_status);
1.1 markus 451: break;
452: }
453:
454: contouch(s);
455: }
456:
457: void
458: conloop(void)
459: {
460: fd_set r, e;
461: struct timeval seltime, now;
462: int i;
463: con *c;
464:
465: gettimeofday(&now, NULL);
466: c = tq.tqh_first;
467:
468: if (c &&
469: (c->c_tv.tv_sec > now.tv_sec ||
470: (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
471: seltime = c->c_tv;
472: seltime.tv_sec -= now.tv_sec;
473: seltime.tv_usec -= now.tv_usec;
474: if ((int) seltime.tv_usec < 0) {
475: seltime.tv_usec += 1000000;
476: seltime.tv_sec--;
477: }
478: } else
479: seltime.tv_sec = seltime.tv_usec = 0;
480:
481: r = e = read_wait;
482: select(maxfd, &r, NULL, &e, &seltime);
483: for (i = 0; i < maxfd; i++)
484: if (FD_ISSET(i, &e)) {
485: error("%s: exception!", fdcon[i].c_name);
486: confree(i);
487: } else if (FD_ISSET(i, &r))
488: conread(i);
489:
490: c = tq.tqh_first;
491: while (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: int s = c->c_fd;
495: c = c->c_link.tqe_next;
496: conrecycle(s);
497: }
498: }
499:
500: char *
501: nexthost(int argc, char **argv)
502: {
503: static Linebuf *lb;
504:
505: for (;;) {
506: if (!lb) {
507: if (argno >= argc)
508: return (NULL);
509: if (argv[argno][0] != '-')
510: return (argv[argno++]);
511: if (!strcmp(argv[argno], "--")) {
512: if (++argno >= argc)
513: return (NULL);
514: return (argv[argno++]);
515: } else if (!strncmp(argv[argno], "-f", 2)) {
516: char *fname;
517: if (argv[argno][2])
518: fname = &argv[argno++][2];
519: else if (++argno >= argc) {
520: error("missing filename for `-f'");
521: return (NULL);
522: } else
523: fname = argv[argno++];
524: if (!strcmp(fname, "-"))
525: fname = NULL;
1.2 markus 526: lb = Linebuf_alloc(fname, error);
1.1 markus 527: } else
528: error("ignoring invalid/misplaced option `%s'", argv[argno++]);
529: } else {
530: char *line;
531: line = getline(lb);
532: if (line)
533: return (line);
534: Linebuf_free(lb);
535: lb = NULL;
536: }
537: }
538: }
539:
540: static void
541: usage(void)
542: {
1.4 markus 543: fatal("usage: %s [-t timeout] { [--] host | -f file } ...", __progname);
1.1 markus 544: return;
545: }
546:
547: int
548: main(int argc, char **argv)
549: {
550: char *host = NULL;
551:
552: TAILQ_INIT(&tq);
553:
554: if (argc <= argno)
555: usage();
556:
557: if (argv[1][0] == '-' && argv[1][1] == 't') {
558: argno++;
559: if (argv[1][2])
560: timeout = atoi(&argv[1][2]);
561: else {
562: if (argno >= argc)
563: usage();
564: timeout = atoi(argv[argno++]);
565: }
566: if (timeout <= 0)
567: usage();
568: }
569: if (argc <= argno)
570: usage();
571:
572: maxfd = fdlim_get(1);
573: if (maxfd < 0)
1.4 markus 574: fatal("%s: fdlim_get: bad value", __progname);
1.1 markus 575: if (maxfd > MAXMAXFD)
576: maxfd = MAXMAXFD;
577: if (maxcon <= 0)
1.4 markus 578: fatal("%s: not enough file descriptors", __progname);
1.1 markus 579: if (maxfd > fdlim_get(0))
580: fdlim_set(maxfd);
581: fdcon = xmalloc(maxfd * sizeof(con));
582:
583: do {
584: while (ncon < maxcon) {
585: char *name;
586:
587: host = nexthost(argc, argv);
588: if (host == NULL)
589: break;
590: name = strnnsep(&host, " \t\n");
591: conalloc(name, *host ? host : name);
592: }
593: conloop();
594: } while (host);
595: while (ncon > 0)
596: conloop();
597:
598: return (0);
599: }