xref: /freebsd/crypto/heimdal/appl/rsh/rsh.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /*
2  * Copyright (c) 1997 - 2003 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "rsh_locl.h"
35 RCSID("$Id: rsh.c,v 1.71 2003/04/16 20:37:20 joda Exp $");
36 
37 enum auth_method auth_method;
38 #if defined(KRB4) || defined(KRB5)
39 int do_encrypt       = -1;
40 #endif
41 #ifdef KRB5
42 int do_unique_tkfile = 0;
43 char *unique_tkfile  = NULL;
44 char tkfile[MAXPATHLEN];
45 int do_forward       = -1;
46 int do_forwardable   = -1;
47 krb5_context context;
48 krb5_keyblock *keyblock;
49 krb5_crypto crypto;
50 #endif
51 #ifdef KRB4
52 des_key_schedule schedule;
53 des_cblock iv;
54 #endif
55 int sock_debug	     = 0;
56 
57 #ifdef KRB4
58 static int use_v4 = -1;
59 #endif
60 #ifdef KRB5
61 static int use_v5 = -1;
62 #endif
63 static int use_only_broken = 0;
64 static int use_broken = 1;
65 static char *port_str;
66 static const char *user;
67 static int do_version;
68 static int do_help;
69 static int do_errsock = 1;
70 static char *protocol_version_str;
71 static int protocol_version = 2;
72 
73 /*
74  *
75  */
76 
77 static int input = 1;		/* Read from stdin */
78 
79 static int
80 loop (int s, int errsock)
81 {
82     fd_set real_readset;
83     int count = 1;
84 
85 #ifdef KRB5
86     if(auth_method == AUTH_KRB5 && protocol_version == 2)
87 	init_ivecs(1);
88 #endif
89 
90     if (s >= FD_SETSIZE || (errsock != -1 && errsock >= FD_SETSIZE))
91 	errx (1, "fd too large");
92 
93     FD_ZERO(&real_readset);
94     FD_SET(s, &real_readset);
95     if (errsock != -1) {
96 	FD_SET(errsock, &real_readset);
97 	++count;
98     }
99     if(input)
100 	FD_SET(STDIN_FILENO, &real_readset);
101 
102     for (;;) {
103 	int ret;
104 	fd_set readset;
105 	char buf[RSH_BUFSIZ];
106 
107 	readset = real_readset;
108 	ret = select (max(s, errsock) + 1, &readset, NULL, NULL, NULL);
109 	if (ret < 0) {
110 	    if (errno == EINTR)
111 		continue;
112 	    else
113 		err (1, "select");
114 	}
115 	if (FD_ISSET(s, &readset)) {
116 	    ret = do_read (s, buf, sizeof(buf), ivec_in[0]);
117 	    if (ret < 0)
118 		err (1, "read");
119 	    else if (ret == 0) {
120 		close (s);
121 		FD_CLR(s, &real_readset);
122 		if (--count == 0)
123 		    return 0;
124 	    } else
125 		net_write (STDOUT_FILENO, buf, ret);
126 	}
127 	if (errsock != -1 && FD_ISSET(errsock, &readset)) {
128 	    ret = do_read (errsock, buf, sizeof(buf), ivec_in[1]);
129 	    if (ret < 0)
130 		err (1, "read");
131 	    else if (ret == 0) {
132 		close (errsock);
133 		FD_CLR(errsock, &real_readset);
134 		if (--count == 0)
135 		    return 0;
136 	    } else
137 		net_write (STDERR_FILENO, buf, ret);
138 	}
139 	if (FD_ISSET(STDIN_FILENO, &readset)) {
140 	    ret = read (STDIN_FILENO, buf, sizeof(buf));
141 	    if (ret < 0)
142 		err (1, "read");
143 	    else if (ret == 0) {
144 		close (STDIN_FILENO);
145 		FD_CLR(STDIN_FILENO, &real_readset);
146 		shutdown (s, SHUT_WR);
147 	    } else
148 		do_write (s, buf, ret, ivec_out[0]);
149 	}
150     }
151 }
152 
153 #ifdef KRB4
154 static int
155 send_krb4_auth(int s,
156 	       struct sockaddr *thisaddr,
157 	       struct sockaddr *thataddr,
158 	       const char *hostname,
159 	       const char *remote_user,
160 	       const char *local_user,
161 	       size_t cmd_len,
162 	       const char *cmd)
163 {
164     KTEXT_ST text;
165     CREDENTIALS cred;
166     MSG_DAT msg;
167     int status;
168     size_t len;
169 
170     /* the normal default for krb4 should be to disable encryption */
171     status = krb_sendauth ((do_encrypt == 1) ? KOPT_DO_MUTUAL : 0,
172 			   s, &text, "rcmd",
173 			   (char *)hostname, krb_realmofhost (hostname),
174 			   getpid(), &msg, &cred, schedule,
175 			   (struct sockaddr_in *)thisaddr,
176 			   (struct sockaddr_in *)thataddr,
177 			   KCMD_OLD_VERSION);
178     if (status != KSUCCESS) {
179 	warnx("%s: %s", hostname, krb_get_err_text(status));
180 	return 1;
181     }
182     memcpy (iv, cred.session, sizeof(iv));
183 
184     len = strlen(remote_user) + 1;
185     if (net_write (s, remote_user, len) != len) {
186 	warn("write");
187 	return 1;
188     }
189     if (net_write (s, cmd, cmd_len) != cmd_len) {
190 	warn("write");
191 	return 1;
192     }
193     return 0;
194 }
195 #endif /* KRB4 */
196 
197 #ifdef KRB5
198 /*
199  * Send forward information on `s' for host `hostname', them being
200  * forwardable themselves if `forwardable'
201  */
202 
203 static int
204 krb5_forward_cred (krb5_auth_context auth_context,
205 		   int s,
206 		   const char *hostname,
207 		   int forwardable)
208 {
209     krb5_error_code ret;
210     krb5_ccache     ccache;
211     krb5_creds      creds;
212     krb5_kdc_flags  flags;
213     krb5_data       out_data;
214     krb5_principal  principal;
215 
216     memset (&creds, 0, sizeof(creds));
217 
218     ret = krb5_cc_default (context, &ccache);
219     if (ret) {
220 	warnx ("could not forward creds: krb5_cc_default: %s",
221 	       krb5_get_err_text (context, ret));
222 	return 1;
223     }
224 
225     ret = krb5_cc_get_principal (context, ccache, &principal);
226     if (ret) {
227 	warnx ("could not forward creds: krb5_cc_get_principal: %s",
228 	       krb5_get_err_text (context, ret));
229 	return 1;
230     }
231 
232     creds.client = principal;
233 
234     ret = krb5_build_principal (context,
235 				&creds.server,
236 				strlen(principal->realm),
237 				principal->realm,
238 				"krbtgt",
239 				principal->realm,
240 				NULL);
241 
242     if (ret) {
243 	warnx ("could not forward creds: krb5_build_principal: %s",
244 	       krb5_get_err_text (context, ret));
245 	return 1;
246     }
247 
248     creds.times.endtime = 0;
249 
250     flags.i = 0;
251     flags.b.forwarded   = 1;
252     flags.b.forwardable = forwardable;
253 
254     ret = krb5_get_forwarded_creds (context,
255 				    auth_context,
256 				    ccache,
257 				    flags.i,
258 				    hostname,
259 				    &creds,
260 				    &out_data);
261     if (ret) {
262 	warnx ("could not forward creds: krb5_get_forwarded_creds: %s",
263 	       krb5_get_err_text (context, ret));
264 	return 1;
265     }
266 
267     ret = krb5_write_message (context,
268 			      (void *)&s,
269 			      &out_data);
270     krb5_data_free (&out_data);
271 
272     if (ret)
273 	warnx ("could not forward creds: krb5_write_message: %s",
274 	       krb5_get_err_text (context, ret));
275     return 0;
276 }
277 
278 static int sendauth_version_error;
279 
280 static int
281 send_krb5_auth(int s,
282 	       struct sockaddr *thisaddr,
283 	       struct sockaddr *thataddr,
284 	       const char *hostname,
285 	       const char *remote_user,
286 	       const char *local_user,
287 	       size_t cmd_len,
288 	       const char *cmd)
289 {
290     krb5_principal server;
291     krb5_data cksum_data;
292     int status;
293     size_t len;
294     krb5_auth_context auth_context = NULL;
295     const char *protocol_string = NULL;
296     krb5_flags ap_opts;
297 
298     status = krb5_sname_to_principal(context,
299 				     hostname,
300 				     "host",
301 				     KRB5_NT_SRV_HST,
302 				     &server);
303     if (status) {
304 	warnx ("%s: %s", hostname, krb5_get_err_text(context, status));
305 	return 1;
306     }
307 
308     if(do_encrypt == -1) {
309 	krb5_appdefault_boolean(context, NULL,
310 				krb5_principal_get_realm(context, server),
311 				"encrypt",
312 				FALSE,
313 				&do_encrypt);
314     }
315 
316     cksum_data.length = asprintf ((char **)&cksum_data.data,
317 				  "%u:%s%s%s",
318 				  ntohs(socket_get_port(thataddr)),
319 				  do_encrypt ? "-x " : "",
320 				  cmd,
321 				  remote_user);
322 
323     ap_opts = 0;
324 
325     if(do_encrypt)
326 	ap_opts |= AP_OPTS_MUTUAL_REQUIRED;
327 
328     switch(protocol_version) {
329     case 2:
330 	ap_opts |= AP_OPTS_USE_SUBKEY;
331 	protocol_string = KCMD_NEW_VERSION;
332 	break;
333     case 1:
334 	protocol_string = KCMD_OLD_VERSION;
335 	key_usage = KRB5_KU_OTHER_ENCRYPTED;
336 	break;
337     default:
338 	abort();
339     }
340 
341     status = krb5_sendauth (context,
342 			    &auth_context,
343 			    &s,
344 			    protocol_string,
345 			    NULL,
346 			    server,
347 			    ap_opts,
348 			    &cksum_data,
349 			    NULL,
350 			    NULL,
351 			    NULL,
352 			    NULL,
353 			    NULL);
354 
355     /* do this while we have a principal */
356     if(do_forward == -1 || do_forwardable == -1) {
357 	krb5_const_realm realm = krb5_principal_get_realm(context, server);
358 	if (do_forwardable == -1)
359 	    krb5_appdefault_boolean(context, NULL, realm,
360 				    "forwardable", FALSE,
361 				    &do_forwardable);
362 	if (do_forward == -1)
363 	    krb5_appdefault_boolean(context, NULL, realm,
364 				    "forward", FALSE,
365 				    &do_forward);
366     }
367 
368     krb5_free_principal(context, server);
369     krb5_data_free(&cksum_data);
370 
371     if (status) {
372 	if(status == KRB5_SENDAUTH_REJECTED &&
373 	   protocol_version == 2 && protocol_version_str == NULL)
374 	    sendauth_version_error = 1;
375 	else
376 	    krb5_warn(context, status, "%s", hostname);
377 	return 1;
378     }
379 
380     status = krb5_auth_con_getlocalsubkey (context, auth_context, &keyblock);
381     if(keyblock == NULL)
382 	status = krb5_auth_con_getkey (context, auth_context, &keyblock);
383     if (status) {
384 	warnx ("krb5_auth_con_getkey: %s", krb5_get_err_text(context, status));
385 	return 1;
386     }
387 
388     status = krb5_auth_con_setaddrs_from_fd (context,
389 					     auth_context,
390 					     &s);
391     if (status) {
392         warnx("krb5_auth_con_setaddrs_from_fd: %s",
393 	      krb5_get_err_text(context, status));
394         return(1);
395     }
396 
397     status = krb5_crypto_init(context, keyblock, 0, &crypto);
398     if(status) {
399 	warnx ("krb5_crypto_init: %s", krb5_get_err_text(context, status));
400 	return 1;
401     }
402 
403     len = strlen(remote_user) + 1;
404     if (net_write (s, remote_user, len) != len) {
405 	warn ("write");
406 	return 1;
407     }
408     if (do_encrypt && net_write (s, "-x ", 3) != 3) {
409 	warn ("write");
410 	return 1;
411     }
412     if (net_write (s, cmd, cmd_len) != cmd_len) {
413 	warn ("write");
414 	return 1;
415     }
416 
417     if (do_unique_tkfile) {
418 	if (net_write (s, tkfile, strlen(tkfile)) != strlen(tkfile)) {
419 	    warn ("write");
420 	    return 1;
421 	}
422     }
423     len = strlen(local_user) + 1;
424     if (net_write (s, local_user, len) != len) {
425 	warn ("write");
426 	return 1;
427     }
428 
429     if (!do_forward
430 	|| krb5_forward_cred (auth_context, s, hostname, do_forwardable)) {
431 	/* Empty forwarding info */
432 
433 	u_char zero[4] = {0, 0, 0, 0};
434 	write (s, &zero, 4);
435     }
436     krb5_auth_con_free (context, auth_context);
437     return 0;
438 }
439 
440 #endif /* KRB5 */
441 
442 static int
443 send_broken_auth(int s,
444 		 struct sockaddr *thisaddr,
445 		 struct sockaddr *thataddr,
446 		 const char *hostname,
447 		 const char *remote_user,
448 		 const char *local_user,
449 		 size_t cmd_len,
450 		 const char *cmd)
451 {
452     size_t len;
453 
454     len = strlen(local_user) + 1;
455     if (net_write (s, local_user, len) != len) {
456 	warn ("write");
457 	return 1;
458     }
459     len = strlen(remote_user) + 1;
460     if (net_write (s, remote_user, len) != len) {
461 	warn ("write");
462 	return 1;
463     }
464     if (net_write (s, cmd, cmd_len) != cmd_len) {
465 	warn ("write");
466 	return 1;
467     }
468     return 0;
469 }
470 
471 static int
472 proto (int s, int errsock,
473        const char *hostname, const char *local_user, const char *remote_user,
474        const char *cmd, size_t cmd_len,
475        int (*auth_func)(int s,
476 			struct sockaddr *this, struct sockaddr *that,
477 			const char *hostname, const char *remote_user,
478 			const char *local_user, size_t cmd_len,
479 			const char *cmd))
480 {
481     int errsock2;
482     char buf[BUFSIZ];
483     char *p;
484     size_t len;
485     char reply;
486     struct sockaddr_storage thisaddr_ss;
487     struct sockaddr *thisaddr = (struct sockaddr *)&thisaddr_ss;
488     struct sockaddr_storage thataddr_ss;
489     struct sockaddr *thataddr = (struct sockaddr *)&thataddr_ss;
490     struct sockaddr_storage erraddr_ss;
491     struct sockaddr *erraddr = (struct sockaddr *)&erraddr_ss;
492     socklen_t addrlen;
493     int ret;
494 
495     addrlen = sizeof(thisaddr_ss);
496     if (getsockname (s, thisaddr, &addrlen) < 0) {
497 	warn ("getsockname(%s)", hostname);
498 	return 1;
499     }
500     addrlen = sizeof(thataddr_ss);
501     if (getpeername (s, thataddr, &addrlen) < 0) {
502 	warn ("getpeername(%s)", hostname);
503 	return 1;
504     }
505 
506     if (errsock != -1) {
507 
508 	addrlen = sizeof(erraddr_ss);
509 	if (getsockname (errsock, erraddr, &addrlen) < 0) {
510 	    warn ("getsockname");
511 	    return 1;
512 	}
513 
514 	if (listen (errsock, 1) < 0) {
515 	    warn ("listen");
516 	    return 1;
517 	}
518 
519 	p = buf;
520 	snprintf (p, sizeof(buf), "%u",
521 		  ntohs(socket_get_port(erraddr)));
522 	len = strlen(buf) + 1;
523 	if(net_write (s, buf, len) != len) {
524 	    warn ("write");
525 	    close (errsock);
526 	    return 1;
527 	}
528 
529 
530 	for (;;) {
531 	    fd_set fdset;
532 
533 	    if (errsock >= FD_SETSIZE || s >= FD_SETSIZE)
534 		errx (1, "fd too large");
535 
536 	    FD_ZERO(&fdset);
537 	    FD_SET(errsock, &fdset);
538 	    FD_SET(s, &fdset);
539 
540 	    ret = select (max(errsock, s) + 1, &fdset, NULL, NULL, NULL);
541 	    if (ret < 0) {
542 		if (errno == EINTR)
543 		    continue;
544 		warn ("select");
545 		close (errsock);
546 		return 1;
547 	    }
548 	    if (FD_ISSET(errsock, &fdset)) {
549 		errsock2 = accept (errsock, NULL, NULL);
550 		close (errsock);
551 		if (errsock2 < 0) {
552 		    warn ("accept");
553 		    return 1;
554 		}
555 		break;
556 	    }
557 
558 	    /*
559 	     * there should not arrive any data on this fd so if it's
560 	     * readable it probably indicates that the other side when
561 	     * away.
562 	     */
563 
564 	    if (FD_ISSET(s, &fdset)) {
565 		warnx ("socket closed");
566 		close (errsock);
567 		errsock2 = -1;
568 		break;
569 	    }
570 	}
571     } else {
572 	if (net_write (s, "0", 2) != 2) {
573 	    warn ("write");
574 	    return 1;
575 	}
576 	errsock2 = -1;
577     }
578 
579     if ((*auth_func)(s, thisaddr, thataddr, hostname,
580 		     remote_user, local_user,
581 		     cmd_len, cmd)) {
582 	close (errsock2);
583 	return 1;
584     }
585 
586     ret = net_read (s, &reply, 1);
587     if (ret < 0) {
588 	warn ("read");
589 	close (errsock2);
590 	return 1;
591     } else if (ret == 0) {
592 	warnx ("unexpected EOF from %s", hostname);
593 	close (errsock2);
594 	return 1;
595     }
596     if (reply != 0) {
597 
598 	warnx ("Error from rshd at %s:", hostname);
599 
600 	while ((ret = read (s, buf, sizeof(buf))) > 0)
601 	    write (STDOUT_FILENO, buf, ret);
602         write (STDOUT_FILENO,"\n",1);
603 	close (errsock2);
604 	return 1;
605     }
606 
607     if (sock_debug) {
608 	int one = 1;
609 	if (setsockopt(s, SOL_SOCKET, SO_DEBUG, (void *)&one, sizeof(one)) < 0)
610 	    warn("setsockopt remote");
611 	if (errsock2 != -1 &&
612 	    setsockopt(errsock2, SOL_SOCKET, SO_DEBUG,
613 		       (void *)&one, sizeof(one)) < 0)
614 	    warn("setsockopt stderr");
615     }
616 
617     return loop (s, errsock2);
618 }
619 
620 /*
621  * Return in `res' a copy of the concatenation of `argc, argv' into
622  * malloced space.  */
623 
624 static size_t
625 construct_command (char **res, int argc, char **argv)
626 {
627     int i;
628     size_t len = 0;
629     char *tmp;
630 
631     for (i = 0; i < argc; ++i)
632 	len += strlen(argv[i]) + 1;
633     len = max (1, len);
634     tmp = malloc (len);
635     if (tmp == NULL)
636 	errx (1, "malloc %u failed", len);
637 
638     *tmp = '\0';
639     for (i = 0; i < argc - 1; ++i) {
640 	strcat (tmp, argv[i]);
641 	strcat (tmp, " ");
642     }
643     if (argc > 0)
644 	strcat (tmp, argv[argc-1]);
645     *res = tmp;
646     return len;
647 }
648 
649 static char *
650 print_addr (const struct sockaddr *sa)
651 {
652     char addr_str[256];
653     char *res;
654     const char *as = NULL;
655 
656     if(sa->sa_family == AF_INET)
657 	as = inet_ntop (sa->sa_family, &((struct sockaddr_in*)sa)->sin_addr,
658 			addr_str, sizeof(addr_str));
659 #ifdef HAVE_INET6
660     else if(sa->sa_family == AF_INET6)
661 	as = inet_ntop (sa->sa_family, &((struct sockaddr_in6*)sa)->sin6_addr,
662 			addr_str, sizeof(addr_str));
663 #endif
664     if(as == NULL)
665 	return NULL;
666     res = strdup(as);
667     if (res == NULL)
668 	errx (1, "malloc: out of memory");
669     return res;
670 }
671 
672 static int
673 doit_broken (int argc,
674 	     char **argv,
675 	     int hostindex,
676 	     struct addrinfo *ai,
677 	     const char *remote_user,
678 	     const char *local_user,
679 	     int priv_socket1,
680 	     int priv_socket2,
681 	     const char *cmd,
682 	     size_t cmd_len)
683 {
684     struct addrinfo *a;
685 
686     if (connect (priv_socket1, ai->ai_addr, ai->ai_addrlen) < 0) {
687 	int save_errno = errno;
688 
689 	close(priv_socket1);
690 	close(priv_socket2);
691 
692 	for (a = ai->ai_next; a != NULL; a = a->ai_next) {
693 	    pid_t pid;
694 	    char *adr = print_addr(a->ai_addr);
695 	    if(adr == NULL)
696 		continue;
697 
698 	    pid = fork();
699 	    if (pid < 0)
700 		err (1, "fork");
701 	    else if(pid == 0) {
702 		char **new_argv;
703 		int i = 0;
704 
705 		new_argv = malloc((argc + 2) * sizeof(*new_argv));
706 		if (new_argv == NULL)
707 		    errx (1, "malloc: out of memory");
708 		new_argv[i] = argv[i];
709 		++i;
710 		if (hostindex == i)
711 		    new_argv[i++] = adr;
712 		new_argv[i++] = "-K";
713 		for(; i <= argc; ++i)
714 		    new_argv[i] = argv[i - 1];
715 		if (hostindex > 1)
716 		    new_argv[hostindex + 1] = adr;
717 		new_argv[argc + 1] = NULL;
718 		execv(PATH_RSH, new_argv);
719 		err(1, "execv(%s)", PATH_RSH);
720 	    } else {
721 		int status;
722 		free(adr);
723 
724 		while(waitpid(pid, &status, 0) < 0)
725 		    ;
726 		if(WIFEXITED(status) && WEXITSTATUS(status) == 0)
727 		    return 0;
728 	    }
729 	}
730 	errno = save_errno;
731 	warn("%s", argv[hostindex]);
732 	return 1;
733     } else {
734 	int ret;
735 
736 	ret = proto (priv_socket1, priv_socket2,
737 		     argv[hostindex],
738 		     local_user, remote_user,
739 		     cmd, cmd_len,
740 		     send_broken_auth);
741 	return ret;
742     }
743 }
744 
745 #if defined(KRB4) || defined(KRB5)
746 static int
747 doit (const char *hostname,
748       struct addrinfo *ai,
749       const char *remote_user,
750       const char *local_user,
751       const char *cmd,
752       size_t cmd_len,
753       int do_errsock,
754       int (*auth_func)(int s,
755 		       struct sockaddr *this, struct sockaddr *that,
756 		       const char *hostname, const char *remote_user,
757 		       const char *local_user, size_t cmd_len,
758 		       const char *cmd))
759 {
760     int error;
761     struct addrinfo *a;
762     int socketfailed = 1;
763     int ret;
764 
765     for (a = ai; a != NULL; a = a->ai_next) {
766 	int s;
767 	int errsock;
768 
769 	s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
770 	if (s < 0)
771 	    continue;
772 	socketfailed = 0;
773 	if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
774 	    char addr[128];
775 	    if(getnameinfo(a->ai_addr, a->ai_addrlen,
776 			   addr, sizeof(addr), NULL, 0, NI_NUMERICHOST) == 0)
777 		warn ("connect(%s [%s])", hostname, addr);
778 	    else
779 		warn ("connect(%s)", hostname);
780 	    close (s);
781 	    continue;
782 	}
783 	if (do_errsock) {
784 	    struct addrinfo *ea, *eai;
785 	    struct addrinfo hints;
786 
787 	    memset (&hints, 0, sizeof(hints));
788 	    hints.ai_socktype = a->ai_socktype;
789 	    hints.ai_protocol = a->ai_protocol;
790 	    hints.ai_family   = a->ai_family;
791 	    hints.ai_flags    = AI_PASSIVE;
792 
793 	    errsock = -1;
794 
795 	    error = getaddrinfo (NULL, "0", &hints, &eai);
796 	    if (error)
797 		errx (1, "getaddrinfo: %s", gai_strerror(error));
798 	    for (ea = eai; ea != NULL; ea = ea->ai_next) {
799 		errsock = socket (ea->ai_family, ea->ai_socktype,
800 				  ea->ai_protocol);
801 		if (errsock < 0)
802 		    continue;
803 		if (bind (errsock, ea->ai_addr, ea->ai_addrlen) < 0)
804 		    err (1, "bind");
805 		break;
806 	    }
807 	    if (errsock < 0)
808 		err (1, "socket");
809 	    freeaddrinfo (eai);
810 	} else
811 	    errsock = -1;
812 
813 	ret = proto (s, errsock,
814 		     hostname,
815 		     local_user, remote_user,
816 		     cmd, cmd_len, auth_func);
817 	close (s);
818 	return ret;
819     }
820     if(socketfailed)
821 	warnx ("failed to contact %s", hostname);
822     return -1;
823 }
824 #endif /* KRB4 || KRB5 */
825 
826 struct getargs args[] = {
827 #ifdef KRB4
828     { "krb4",	'4', arg_flag,		&use_v4,	"Use Kerberos V4" },
829 #endif
830 #ifdef KRB5
831     { "krb5",	'5', arg_flag,		&use_v5,	"Use Kerberos V5" },
832     { "forward", 'f', arg_flag,		&do_forward,	"Forward credentials (krb5)"},
833     { NULL, 'G', arg_negative_flag,&do_forward,	"Don't forward credentials" },
834     { "forwardable", 'F', arg_flag,	&do_forwardable,
835       "Forward forwardable credentials" },
836 #endif
837 #if defined(KRB4) || defined(KRB5)
838     { "broken", 'K', arg_flag,		&use_only_broken, "Use only priv port" },
839     { "encrypt", 'x', arg_flag,		&do_encrypt,	"Encrypt connection" },
840     { NULL, 	'z', arg_negative_flag,      &do_encrypt,
841       "Don't encrypt connection", NULL },
842 #endif
843 #ifdef KRB5
844     { "unique", 'u', arg_flag,	&do_unique_tkfile,
845       "Use unique remote tkfile (krb5)" },
846     { "tkfile", 'U', arg_string,  &unique_tkfile,
847       "Use that remote tkfile (krb5)" },
848 #endif
849     { NULL,	'd', arg_flag,		&sock_debug, "Enable socket debugging" },
850     { "input",	'n', arg_negative_flag,	&input,		"Close stdin" },
851     { "port",	'p', arg_string,	&port_str,	"Use this port",
852       "port" },
853     { "user",	'l', arg_string,	&user,		"Run as this user", "login" },
854     { "stderr", 'e', arg_negative_flag, &do_errsock,	"Don't open stderr"},
855     { "protocol", 'P', arg_string,      &protocol_version_str,
856       "Protocol version", "protocol" },
857     { "version", 0,  arg_flag,		&do_version,	NULL },
858     { "help",	 0,  arg_flag,		&do_help,	NULL }
859 };
860 
861 static void
862 usage (int ret)
863 {
864     arg_printusage (args,
865 		    sizeof(args) / sizeof(args[0]),
866 		    NULL,
867 		    "[login@]host [command]");
868     exit (ret);
869 }
870 
871 /*
872  *
873  */
874 
875 int
876 main(int argc, char **argv)
877 {
878     int priv_port1, priv_port2;
879     int priv_socket1, priv_socket2;
880     int argindex = 0;
881     int error;
882     struct addrinfo hints, *ai;
883     int ret = 1;
884     char *cmd;
885     char *tmp;
886     size_t cmd_len;
887     const char *local_user;
888     char *host = NULL;
889     int host_index = -1;
890 #ifdef KRB5
891     int status;
892 #endif
893     uid_t uid;
894 
895     priv_port1 = priv_port2 = IPPORT_RESERVED-1;
896     priv_socket1 = rresvport(&priv_port1);
897     priv_socket2 = rresvport(&priv_port2);
898     uid = getuid ();
899     if (setuid (uid) || (uid != 0 && setuid(0) == 0))
900 	err (1, "setuid");
901 
902     setprogname (argv[0]);
903 
904     if (argc >= 2 && argv[1][0] != '-') {
905 	host = argv[host_index = 1];
906 	argindex = 1;
907     }
908 
909     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
910 		&argindex))
911 	usage (1);
912 
913     if (do_help)
914 	usage (0);
915 
916     if (do_version) {
917 	print_version (NULL);
918 	return 0;
919     }
920 
921     if(protocol_version_str != NULL) {
922 	if(strcasecmp(protocol_version_str, "N") == 0)
923 	    protocol_version = 2;
924 	else if(strcasecmp(protocol_version_str, "O") == 0)
925 	    protocol_version = 1;
926 	else {
927 	    char *end;
928 	    int v;
929 	    v = strtol(protocol_version_str, &end, 0);
930 	    if(*end != '\0' || (v != 1 && v != 2)) {
931 		errx(1, "unknown protocol version \"%s\"",
932 		     protocol_version_str);
933 	    }
934 	    protocol_version = v;
935 	}
936     }
937 
938 #ifdef KRB5
939     status = krb5_init_context (&context);
940     if (status) {
941 	if(use_v5 == 1)
942 	    errx(1, "krb5_init_context failed: %d", status);
943 	else
944 	    use_v5 = 0;
945     }
946 
947     /* request for forwardable on the command line means we should
948        also forward */
949     if (do_forwardable == 1)
950 	do_forward = 1;
951 
952 #endif
953 
954 #if defined(KRB4) && defined(KRB5)
955     if(use_v4 == -1 && use_v5 == 1)
956 	use_v4 = 0;
957     if(use_v5 == -1 && use_v4 == 1)
958 	use_v5 = 0;
959 #endif
960 
961     if (use_only_broken) {
962 #ifdef KRB4
963 	use_v4 = 0;
964 #endif
965 #ifdef KRB5
966 	use_v5 = 0;
967 #endif
968     }
969 
970     if(priv_socket1 < 0) {
971 	if (use_only_broken)
972 	    errx (1, "unable to bind reserved port: is rsh setuid root?");
973 	use_broken = 0;
974     }
975 
976 #if defined(KRB4) || defined(KRB5)
977     if (do_encrypt == 1 && use_only_broken)
978 	errx (1, "encryption not supported with old style authentication");
979 #endif
980 
981 
982 
983 #ifdef KRB5
984     if (do_unique_tkfile && unique_tkfile != NULL)
985 	errx (1, "Only one of -u and -U allowed.");
986 
987     if (do_unique_tkfile)
988 	strcpy(tkfile,"-u ");
989     else if (unique_tkfile != NULL) {
990 	if (strchr(unique_tkfile,' ') != NULL) {
991 	    warnx("Space is not allowed in tkfilename");
992 	    usage(1);
993 	}
994 	do_unique_tkfile = 1;
995 	snprintf (tkfile, sizeof(tkfile), "-U %s ", unique_tkfile);
996     }
997 #endif
998 
999     if (host == NULL) {
1000 	if (argc - argindex < 1)
1001 	    usage (1);
1002 	else
1003 	    host = argv[host_index = argindex++];
1004     }
1005 
1006     if((tmp = strchr(host, '@')) != NULL) {
1007 	*tmp++ = '\0';
1008 	user = host;
1009 	host = tmp;
1010     }
1011 
1012     if (argindex == argc) {
1013 	close (priv_socket1);
1014 	close (priv_socket2);
1015 	argv[0] = "rlogin";
1016 	execvp ("rlogin", argv);
1017 	err (1, "execvp rlogin");
1018     }
1019 
1020     local_user = get_default_username ();
1021     if (local_user == NULL)
1022 	errx (1, "who are you?");
1023 
1024     if (user == NULL)
1025 	user = local_user;
1026 
1027     cmd_len = construct_command(&cmd, argc - argindex, argv + argindex);
1028 
1029     /*
1030      * Try all different authentication methods
1031      */
1032 
1033 #ifdef KRB5
1034     if (ret && use_v5) {
1035 	memset (&hints, 0, sizeof(hints));
1036 	hints.ai_socktype = SOCK_STREAM;
1037 	hints.ai_protocol = IPPROTO_TCP;
1038 
1039 	if(port_str == NULL) {
1040 	    error = getaddrinfo(host, "kshell", &hints, &ai);
1041 	    if(error == EAI_NONAME)
1042 		error = getaddrinfo(host, "544", &hints, &ai);
1043 	} else
1044 	    error = getaddrinfo(host, port_str, &hints, &ai);
1045 
1046 	if(error)
1047 	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1048 
1049 	auth_method = AUTH_KRB5;
1050       again:
1051 	ret = doit (host, ai, user, local_user, cmd, cmd_len,
1052 		    do_errsock,
1053 		    send_krb5_auth);
1054 	if(ret != 0 && sendauth_version_error &&
1055 	   protocol_version == 2) {
1056 	    protocol_version = 1;
1057 	    goto again;
1058 	}
1059 	freeaddrinfo(ai);
1060     }
1061 #endif
1062 #ifdef KRB4
1063     if (ret && use_v4) {
1064 	memset (&hints, 0, sizeof(hints));
1065 	hints.ai_socktype = SOCK_STREAM;
1066 	hints.ai_protocol = IPPROTO_TCP;
1067 
1068 	if(port_str == NULL) {
1069 	    if(do_encrypt) {
1070 		error = getaddrinfo(host, "ekshell", &hints, &ai);
1071 		if(error == EAI_NONAME)
1072 		    error = getaddrinfo(host, "545", &hints, &ai);
1073 	    } else {
1074 		error = getaddrinfo(host, "kshell", &hints, &ai);
1075 		if(error == EAI_NONAME)
1076 		    error = getaddrinfo(host, "544", &hints, &ai);
1077 	    }
1078 	} else
1079 	    error = getaddrinfo(host, port_str, &hints, &ai);
1080 
1081 	if(error)
1082 	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1083 	auth_method = AUTH_KRB4;
1084 	ret = doit (host, ai, user, local_user, cmd, cmd_len,
1085 		    do_errsock,
1086 		    send_krb4_auth);
1087 	freeaddrinfo(ai);
1088     }
1089 #endif
1090     if (ret && use_broken) {
1091 	memset (&hints, 0, sizeof(hints));
1092 	hints.ai_socktype = SOCK_STREAM;
1093 	hints.ai_protocol = IPPROTO_TCP;
1094 
1095 	if(port_str == NULL) {
1096 	    error = getaddrinfo(host, "shell", &hints, &ai);
1097 	    if(error == EAI_NONAME)
1098 		error = getaddrinfo(host, "514", &hints, &ai);
1099 	} else
1100 	    error = getaddrinfo(host, port_str, &hints, &ai);
1101 
1102 	if(error)
1103 	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1104 
1105 	auth_method = AUTH_BROKEN;
1106 	ret = doit_broken (argc, argv, host_index, ai,
1107 			   user, local_user,
1108 			   priv_socket1,
1109 			   do_errsock ? priv_socket2 : -1,
1110 			   cmd, cmd_len);
1111 	freeaddrinfo(ai);
1112     }
1113     free(cmd);
1114     return ret;
1115 }
1116