rsh.c revision 103423 
1/*
2 * Copyright (c) 1997 - 2002 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"
35RCSID("$Id: rsh.c,v 1.68 2002/09/04 21:40:04 joda Exp $");
36
37enum auth_method auth_method;
38#if defined(KRB4) || defined(KRB5)
39int do_encrypt       = -1;
40#endif
41#ifdef KRB5
42int do_unique_tkfile = 0;
43char *unique_tkfile  = NULL;
44char tkfile[MAXPATHLEN];
45int do_forward       = -1;
46int do_forwardable   = -1;
47krb5_context context;
48krb5_keyblock *keyblock;
49krb5_crypto crypto;
50#endif
51#ifdef KRB4
52des_key_schedule schedule;
53des_cblock iv;
54#endif
55int sock_debug	     = 0;
56
57#ifdef KRB4
58static int use_v4 = -1;
59#endif
60#ifdef KRB5
61static int use_v5 = -1;
62#endif
63static int use_only_broken = 0;
64static int use_broken = 1;
65static char *port_str;
66static const char *user;
67static int do_version;
68static int do_help;
69static int do_errsock = 1;
70static char *protocol_version_str;
71static int protocol_version = 2;
72
73/*
74 *
75 */
76
77static int input = 1;		/* Read from stdin */
78
79static int
80loop (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 >= 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
154static int
155send_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    status = krb_sendauth (do_encrypt ? KOPT_DO_MUTUAL : 0,
171			   s, &text, "rcmd",
172			   (char *)hostname, krb_realmofhost (hostname),
173			   getpid(), &msg, &cred, schedule,
174			   (struct sockaddr_in *)thisaddr,
175			   (struct sockaddr_in *)thataddr,
176			   KCMD_OLD_VERSION);
177    if (status != KSUCCESS) {
178	warnx("%s: %s", hostname, krb_get_err_text(status));
179	return 1;
180    }
181    memcpy (iv, cred.session, sizeof(iv));
182
183    len = strlen(remote_user) + 1;
184    if (net_write (s, remote_user, len) != len) {
185	warn("write");
186	return 1;
187    }
188    if (net_write (s, cmd, cmd_len) != cmd_len) {
189	warn("write");
190	return 1;
191    }
192    return 0;
193}
194#endif /* KRB4 */
195
196#ifdef KRB5
197/*
198 * Send forward information on `s' for host `hostname', them being
199 * forwardable themselves if `forwardable'
200 */
201
202static int
203krb5_forward_cred (krb5_auth_context auth_context,
204		   int s,
205		   const char *hostname,
206		   int forwardable)
207{
208    krb5_error_code ret;
209    krb5_ccache     ccache;
210    krb5_creds      creds;
211    krb5_kdc_flags  flags;
212    krb5_data       out_data;
213    krb5_principal  principal;
214
215    memset (&creds, 0, sizeof(creds));
216
217    ret = krb5_cc_default (context, &ccache);
218    if (ret) {
219	warnx ("could not forward creds: krb5_cc_default: %s",
220	       krb5_get_err_text (context, ret));
221	return 1;
222    }
223
224    ret = krb5_cc_get_principal (context, ccache, &principal);
225    if (ret) {
226	warnx ("could not forward creds: krb5_cc_get_principal: %s",
227	       krb5_get_err_text (context, ret));
228	return 1;
229    }
230
231    creds.client = principal;
232
233    ret = krb5_build_principal (context,
234				&creds.server,
235				strlen(principal->realm),
236				principal->realm,
237				"krbtgt",
238				principal->realm,
239				NULL);
240
241    if (ret) {
242	warnx ("could not forward creds: krb5_build_principal: %s",
243	       krb5_get_err_text (context, ret));
244	return 1;
245    }
246
247    creds.times.endtime = 0;
248
249    flags.i = 0;
250    flags.b.forwarded   = 1;
251    flags.b.forwardable = forwardable;
252
253    ret = krb5_get_forwarded_creds (context,
254				    auth_context,
255				    ccache,
256				    flags.i,
257				    hostname,
258				    &creds,
259				    &out_data);
260    if (ret) {
261	warnx ("could not forward creds: krb5_get_forwarded_creds: %s",
262	       krb5_get_err_text (context, ret));
263	return 1;
264    }
265
266    ret = krb5_write_message (context,
267			      (void *)&s,
268			      &out_data);
269    krb5_data_free (&out_data);
270
271    if (ret)
272	warnx ("could not forward creds: krb5_write_message: %s",
273	       krb5_get_err_text (context, ret));
274    return 0;
275}
276
277static int sendauth_version_error;
278
279static int
280send_krb5_auth(int s,
281	       struct sockaddr *thisaddr,
282	       struct sockaddr *thataddr,
283	       const char *hostname,
284	       const char *remote_user,
285	       const char *local_user,
286	       size_t cmd_len,
287	       const char *cmd)
288{
289    krb5_principal server;
290    krb5_data cksum_data;
291    int status;
292    size_t len;
293    krb5_auth_context auth_context = NULL;
294    const char *protocol_string = NULL;
295    krb5_flags ap_opts;
296
297    status = krb5_sname_to_principal(context,
298				     hostname,
299				     "host",
300				     KRB5_NT_SRV_HST,
301				     &server);
302    if (status) {
303	warnx ("%s: %s", hostname, krb5_get_err_text(context, status));
304	return 1;
305    }
306
307    cksum_data.length = asprintf ((char **)&cksum_data.data,
308				  "%u:%s%s%s",
309				  ntohs(socket_get_port(thataddr)),
310				  do_encrypt ? "-x " : "",
311				  cmd,
312				  remote_user);
313
314    ap_opts = 0;
315
316    if(do_encrypt)
317	ap_opts |= AP_OPTS_MUTUAL_REQUIRED;
318
319    switch(protocol_version) {
320    case 2:
321	ap_opts |= AP_OPTS_USE_SUBKEY;
322	protocol_string = KCMD_NEW_VERSION;
323	break;
324    case 1:
325	protocol_string = KCMD_OLD_VERSION;
326	key_usage = KRB5_KU_OTHER_ENCRYPTED;
327	break;
328    default:
329	abort();
330    }
331
332    status = krb5_sendauth (context,
333			    &auth_context,
334			    &s,
335			    protocol_string,
336			    NULL,
337			    server,
338			    ap_opts,
339			    &cksum_data,
340			    NULL,
341			    NULL,
342			    NULL,
343			    NULL,
344			    NULL);
345
346    krb5_free_principal(context, server);
347    krb5_data_free(&cksum_data);
348
349    if (status) {
350	if(status == KRB5_SENDAUTH_REJECTED &&
351	   protocol_version == 2 && protocol_version_str == NULL)
352	    sendauth_version_error = 1;
353	else
354	    krb5_warn(context, status, "%s", hostname);
355	return 1;
356    }
357
358    status = krb5_auth_con_getlocalsubkey (context, auth_context, &keyblock);
359    if(keyblock == NULL)
360	status = krb5_auth_con_getkey (context, auth_context, &keyblock);
361    if (status) {
362	warnx ("krb5_auth_con_getkey: %s", krb5_get_err_text(context, status));
363	return 1;
364    }
365
366    status = krb5_auth_con_setaddrs_from_fd (context,
367					     auth_context,
368					     &s);
369    if (status) {
370        warnx("krb5_auth_con_setaddrs_from_fd: %s",
371	      krb5_get_err_text(context, status));
372        return(1);
373    }
374
375    status = krb5_crypto_init(context, keyblock, 0, &crypto);
376    if(status) {
377	warnx ("krb5_crypto_init: %s", krb5_get_err_text(context, status));
378	return 1;
379    }
380
381    len = strlen(remote_user) + 1;
382    if (net_write (s, remote_user, len) != len) {
383	warn ("write");
384	return 1;
385    }
386    if (do_encrypt && net_write (s, "-x ", 3) != 3) {
387	warn ("write");
388	return 1;
389    }
390    if (net_write (s, cmd, cmd_len) != cmd_len) {
391	warn ("write");
392	return 1;
393    }
394
395    if (do_unique_tkfile) {
396	if (net_write (s, tkfile, strlen(tkfile)) != strlen(tkfile)) {
397	    warn ("write");
398	    return 1;
399	}
400    }
401    len = strlen(local_user) + 1;
402    if (net_write (s, local_user, len) != len) {
403	warn ("write");
404	return 1;
405    }
406
407    if (!do_forward
408	|| krb5_forward_cred (auth_context, s, hostname, do_forwardable)) {
409	/* Empty forwarding info */
410
411	u_char zero[4] = {0, 0, 0, 0};
412	write (s, &zero, 4);
413    }
414    krb5_auth_con_free (context, auth_context);
415    return 0;
416}
417
418#endif /* KRB5 */
419
420static int
421send_broken_auth(int s,
422		 struct sockaddr *thisaddr,
423		 struct sockaddr *thataddr,
424		 const char *hostname,
425		 const char *remote_user,
426		 const char *local_user,
427		 size_t cmd_len,
428		 const char *cmd)
429{
430    size_t len;
431
432    len = strlen(local_user) + 1;
433    if (net_write (s, local_user, len) != len) {
434	warn ("write");
435	return 1;
436    }
437    len = strlen(remote_user) + 1;
438    if (net_write (s, remote_user, len) != len) {
439	warn ("write");
440	return 1;
441    }
442    if (net_write (s, cmd, cmd_len) != cmd_len) {
443	warn ("write");
444	return 1;
445    }
446    return 0;
447}
448
449static int
450proto (int s, int errsock,
451       const char *hostname, const char *local_user, const char *remote_user,
452       const char *cmd, size_t cmd_len,
453       int (*auth_func)(int s,
454			struct sockaddr *this, struct sockaddr *that,
455			const char *hostname, const char *remote_user,
456			const char *local_user, size_t cmd_len,
457			const char *cmd))
458{
459    int errsock2;
460    char buf[BUFSIZ];
461    char *p;
462    size_t len;
463    char reply;
464    struct sockaddr_storage thisaddr_ss;
465    struct sockaddr *thisaddr = (struct sockaddr *)&thisaddr_ss;
466    struct sockaddr_storage thataddr_ss;
467    struct sockaddr *thataddr = (struct sockaddr *)&thataddr_ss;
468    struct sockaddr_storage erraddr_ss;
469    struct sockaddr *erraddr = (struct sockaddr *)&erraddr_ss;
470    socklen_t addrlen;
471    int ret;
472
473    addrlen = sizeof(thisaddr_ss);
474    if (getsockname (s, thisaddr, &addrlen) < 0) {
475	warn ("getsockname(%s)", hostname);
476	return 1;
477    }
478    addrlen = sizeof(thataddr_ss);
479    if (getpeername (s, thataddr, &addrlen) < 0) {
480	warn ("getpeername(%s)", hostname);
481	return 1;
482    }
483
484    if (errsock != -1) {
485
486	addrlen = sizeof(erraddr_ss);
487	if (getsockname (errsock, erraddr, &addrlen) < 0) {
488	    warn ("getsockname");
489	    return 1;
490	}
491
492	if (listen (errsock, 1) < 0) {
493	    warn ("listen");
494	    return 1;
495	}
496
497	p = buf;
498	snprintf (p, sizeof(buf), "%u",
499		  ntohs(socket_get_port(erraddr)));
500	len = strlen(buf) + 1;
501	if(net_write (s, buf, len) != len) {
502	    warn ("write");
503	    close (errsock);
504	    return 1;
505	}
506
507
508	for (;;) {
509	    fd_set fdset;
510
511	    if (errsock >= FD_SETSIZE || s >= FD_SETSIZE)
512		errx (1, "fd too large");
513
514	    FD_ZERO(&fdset);
515	    FD_SET(errsock, &fdset);
516	    FD_SET(s, &fdset);
517
518	    ret = select (max(errsock, s) + 1, &fdset, NULL, NULL, NULL);
519	    if (ret < 0) {
520		if (errno == EINTR)
521		    continue;
522		warn ("select");
523		close (errsock);
524		return 1;
525	    }
526	    if (FD_ISSET(errsock, &fdset)) {
527		errsock2 = accept (errsock, NULL, NULL);
528		close (errsock);
529		if (errsock2 < 0) {
530		    warn ("accept");
531		    return 1;
532		}
533		break;
534	    }
535
536	    /*
537	     * there should not arrive any data on this fd so if it's
538	     * readable it probably indicates that the other side when
539	     * away.
540	     */
541
542	    if (FD_ISSET(s, &fdset)) {
543		warnx ("socket closed");
544		close (errsock);
545		errsock2 = -1;
546		break;
547	    }
548	}
549    } else {
550	if (net_write (s, "0", 2) != 2) {
551	    warn ("write");
552	    return 1;
553	}
554	errsock2 = -1;
555    }
556
557    if ((*auth_func)(s, thisaddr, thataddr, hostname,
558		     remote_user, local_user,
559		     cmd_len, cmd)) {
560	close (errsock2);
561	return 1;
562    }
563
564    ret = net_read (s, &reply, 1);
565    if (ret < 0) {
566	warn ("read");
567	close (errsock2);
568	return 1;
569    } else if (ret == 0) {
570	warnx ("unexpected EOF from %s", hostname);
571	close (errsock2);
572	return 1;
573    }
574    if (reply != 0) {
575
576	warnx ("Error from rshd at %s:", hostname);
577
578	while ((ret = read (s, buf, sizeof(buf))) > 0)
579	    write (STDOUT_FILENO, buf, ret);
580        write (STDOUT_FILENO,"\n",1);
581	close (errsock2);
582	return 1;
583    }
584
585    if (sock_debug) {
586	int one = 1;
587	if (setsockopt(s, SOL_SOCKET, SO_DEBUG, (void *)&one, sizeof(one)) < 0)
588	    warn("setsockopt remote");
589	if (errsock2 != -1 &&
590	    setsockopt(errsock2, SOL_SOCKET, SO_DEBUG,
591		       (void *)&one, sizeof(one)) < 0)
592	    warn("setsockopt stderr");
593    }
594
595    return loop (s, errsock2);
596}
597
598/*
599 * Return in `res' a copy of the concatenation of `argc, argv' into
600 * malloced space.  */
601
602static size_t
603construct_command (char **res, int argc, char **argv)
604{
605    int i;
606    size_t len = 0;
607    char *tmp;
608
609    for (i = 0; i < argc; ++i)
610	len += strlen(argv[i]) + 1;
611    len = max (1, len);
612    tmp = malloc (len);
613    if (tmp == NULL)
614	errx (1, "malloc %u failed", len);
615
616    *tmp = '\0';
617    for (i = 0; i < argc - 1; ++i) {
618	strcat (tmp, argv[i]);
619	strcat (tmp, " ");
620    }
621    if (argc > 0)
622	strcat (tmp, argv[argc-1]);
623    *res = tmp;
624    return len;
625}
626
627static char *
628print_addr (const struct sockaddr_in *sin)
629{
630    char addr_str[256];
631    char *res;
632
633    inet_ntop (AF_INET, &sin->sin_addr, addr_str, sizeof(addr_str));
634    res = strdup(addr_str);
635    if (res == NULL)
636	errx (1, "malloc: out of memory");
637    return res;
638}
639
640static int
641doit_broken (int argc,
642	     char **argv,
643	     int optind,
644	     struct addrinfo *ai,
645	     const char *remote_user,
646	     const char *local_user,
647	     int priv_socket1,
648	     int priv_socket2,
649	     const char *cmd,
650	     size_t cmd_len)
651{
652    struct addrinfo *a;
653
654    if (connect (priv_socket1, ai->ai_addr, ai->ai_addrlen) < 0) {
655	if (ai->ai_next == NULL)
656	    return 1;
657
658	close(priv_socket1);
659	close(priv_socket2);
660
661	for (a = ai->ai_next; a != NULL; a = a->ai_next) {
662	    pid_t pid;
663
664	    pid = fork();
665	    if (pid < 0)
666		err (1, "fork");
667	    else if(pid == 0) {
668		char **new_argv;
669		int i = 0;
670		struct sockaddr_in *sin = (struct sockaddr_in *)a->ai_addr;
671
672		new_argv = malloc((argc + 2) * sizeof(*new_argv));
673		if (new_argv == NULL)
674		    errx (1, "malloc: out of memory");
675		new_argv[i] = argv[i];
676		++i;
677		if (optind == i)
678		    new_argv[i++] = print_addr (sin);
679		new_argv[i++] = "-K";
680		for(; i <= argc; ++i)
681		    new_argv[i] = argv[i - 1];
682		if (optind > 1)
683		    new_argv[optind + 1] = print_addr(sin);
684		new_argv[argc + 1] = NULL;
685		execv(PATH_RSH, new_argv);
686		err(1, "execv(%s)", PATH_RSH);
687	    } else {
688		int status;
689
690		while(waitpid(pid, &status, 0) < 0)
691		    ;
692		if(WIFEXITED(status) && WEXITSTATUS(status) == 0)
693		    return 0;
694	    }
695	}
696	return 1;
697    } else {
698	int ret;
699
700	ret = proto (priv_socket1, priv_socket2,
701		     argv[optind],
702		     local_user, remote_user,
703		     cmd, cmd_len,
704		     send_broken_auth);
705	return ret;
706    }
707}
708
709#if defined(KRB4) || defined(KRB5)
710static int
711doit (const char *hostname,
712      struct addrinfo *ai,
713      const char *remote_user,
714      const char *local_user,
715      const char *cmd,
716      size_t cmd_len,
717      int do_errsock,
718      int (*auth_func)(int s,
719		       struct sockaddr *this, struct sockaddr *that,
720		       const char *hostname, const char *remote_user,
721		       const char *local_user, size_t cmd_len,
722		       const char *cmd))
723{
724    int error;
725    struct addrinfo *a;
726    int socketfailed = 1;
727    int ret;
728
729    for (a = ai; a != NULL; a = a->ai_next) {
730	int s;
731	int errsock;
732
733	s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
734	if (s < 0)
735	    continue;
736	socketfailed = 0;
737	if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
738	    char addr[128];
739	    if(getnameinfo(a->ai_addr, a->ai_addrlen,
740			   addr, sizeof(addr), NULL, 0, NI_NUMERICHOST) == 0)
741		warn ("connect(%s [%s])", hostname, addr);
742	    else
743		warn ("connect(%s)", hostname);
744	    close (s);
745	    continue;
746	}
747	if (do_errsock) {
748	    struct addrinfo *ea, *eai;
749	    struct addrinfo hints;
750
751	    memset (&hints, 0, sizeof(hints));
752	    hints.ai_socktype = a->ai_socktype;
753	    hints.ai_protocol = a->ai_protocol;
754	    hints.ai_family   = a->ai_family;
755	    hints.ai_flags    = AI_PASSIVE;
756
757	    errsock = -1;
758
759	    error = getaddrinfo (NULL, "0", &hints, &eai);
760	    if (error)
761		errx (1, "getaddrinfo: %s", gai_strerror(error));
762	    for (ea = eai; ea != NULL; ea = ea->ai_next) {
763		errsock = socket (ea->ai_family, ea->ai_socktype,
764				  ea->ai_protocol);
765		if (errsock < 0)
766		    continue;
767		if (bind (errsock, ea->ai_addr, ea->ai_addrlen) < 0)
768		    err (1, "bind");
769		break;
770	    }
771	    if (errsock < 0)
772		err (1, "socket");
773	    freeaddrinfo (eai);
774	} else
775	    errsock = -1;
776
777	ret = proto (s, errsock,
778		     hostname,
779		     local_user, remote_user,
780		     cmd, cmd_len, auth_func);
781	close (s);
782	return ret;
783    }
784    if(socketfailed)
785	warnx ("failed to contact %s", hostname);
786    return -1;
787}
788#endif /* KRB4 || KRB5 */
789
790struct getargs args[] = {
791#ifdef KRB4
792    { "krb4",	'4', arg_flag,		&use_v4,	"Use Kerberos V4" },
793#endif
794#ifdef KRB5
795    { "krb5",	'5', arg_flag,		&use_v5,	"Use Kerberos V5" },
796    { "forward", 'f', arg_flag,		&do_forward,	"Forward credentials (krb5)"},
797    { NULL, 'G', arg_negative_flag,&do_forward,	"Don't forward credentials" },
798    { "forwardable", 'F', arg_flag,	&do_forwardable,
799      "Forward forwardable credentials" },
800#endif
801#if defined(KRB4) || defined(KRB5)
802    { "broken", 'K', arg_flag,		&use_only_broken, "Use only priv port" },
803    { "encrypt", 'x', arg_flag,		&do_encrypt,	"Encrypt connection" },
804    { NULL, 	'z', arg_negative_flag,      &do_encrypt,
805      "Don't encrypt connection", NULL },
806#endif
807#ifdef KRB5
808    { "unique", 'u', arg_flag,	&do_unique_tkfile,
809      "Use unique remote tkfile (krb5)" },
810    { "tkfile", 'U', arg_string,  &unique_tkfile,
811      "Use that remote tkfile (krb5)" },
812#endif
813    { NULL,	'd', arg_flag,		&sock_debug, "Enable socket debugging" },
814    { "input",	'n', arg_negative_flag,	&input,		"Close stdin" },
815    { "port",	'p', arg_string,	&port_str,	"Use this port",
816      "port" },
817    { "user",	'l', arg_string,	&user,		"Run as this user", "login" },
818    { "stderr", 'e', arg_negative_flag, &do_errsock,	"Don't open stderr"},
819    { "protocol", 'P', arg_string,      &protocol_version_str,
820      "Protocol version", "protocol" },
821    { "version", 0,  arg_flag,		&do_version,	NULL },
822    { "help",	 0,  arg_flag,		&do_help,	NULL }
823};
824
825static void
826usage (int ret)
827{
828    arg_printusage (args,
829		    sizeof(args) / sizeof(args[0]),
830		    NULL,
831		    "[login@]host [command]");
832    exit (ret);
833}
834
835/*
836 *
837 */
838
839int
840main(int argc, char **argv)
841{
842    int priv_port1, priv_port2;
843    int priv_socket1, priv_socket2;
844    int optind = 0;
845    int error;
846    struct addrinfo hints, *ai;
847    int ret = 1;
848    char *cmd;
849    char *tmp;
850    size_t cmd_len;
851    const char *local_user;
852    char *host = NULL;
853    int host_index = -1;
854#ifdef KRB5
855    int status;
856#endif
857    uid_t uid;
858
859    priv_port1 = priv_port2 = IPPORT_RESERVED-1;
860    priv_socket1 = rresvport(&priv_port1);
861    priv_socket2 = rresvport(&priv_port2);
862    uid = getuid ();
863    if (setuid (uid) || (uid != 0 && setuid(0) == 0))
864	err (1, "setuid");
865
866    setprogname (argv[0]);
867
868    if (argc >= 2 && argv[1][0] != '-') {
869	host = argv[host_index = 1];
870	optind = 1;
871    }
872
873    if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
874		&optind))
875	usage (1);
876
877    if (do_help)
878	usage (0);
879
880    if (do_version) {
881	print_version (NULL);
882	return 0;
883    }
884
885    if(protocol_version_str != NULL) {
886	if(strcasecmp(protocol_version_str, "N") == 0)
887	    protocol_version = 2;
888	else if(strcasecmp(protocol_version_str, "O") == 0)
889	    protocol_version = 1;
890	else {
891	    char *end;
892	    int v;
893	    v = strtol(protocol_version_str, &end, 0);
894	    if(*end != '\0' || (v != 1 && v != 2)) {
895		errx(1, "unknown protocol version \"%s\"",
896		     protocol_version_str);
897	    }
898	    protocol_version = v;
899	}
900    }
901
902#ifdef KRB5
903    status = krb5_init_context (&context);
904    if (status) {
905	if(use_v5 == 1)
906	    errx(1, "krb5_init_context failed: %d", status);
907	else
908	    use_v5 = 0;
909    }
910
911    if (do_forwardable == -1)
912	do_forwardable = krb5_config_get_bool (context, NULL,
913					       "libdefaults",
914					       "forwardable",
915					       NULL);
916
917    if (do_forward == -1)
918	do_forward = krb5_config_get_bool (context, NULL,
919					   "libdefaults",
920					   "forward",
921					   NULL);
922    else if (do_forward == 0)
923	do_forwardable = 0;
924
925    if (do_forwardable)
926	do_forward = 1;
927#endif
928#if defined(KRB4) || defined(KRB5)
929    if (do_encrypt == -1) {
930	/* we want to tell the -x flag from the default encryption
931           option */
932#ifdef KRB5
933	/* the normal default for krb4 should be to disable encryption */
934	if(!krb5_config_get_bool (context, NULL,
935				  "libdefaults",
936				  "encrypt",
937				  NULL))
938#endif
939	    do_encrypt = 0;
940    }
941#endif
942
943#if defined(KRB4) && defined(KRB5)
944    if(use_v4 == -1 && use_v5 == 1)
945	use_v4 = 0;
946    if(use_v5 == -1 && use_v4 == 1)
947	use_v5 = 0;
948#endif
949
950    if (use_only_broken) {
951#ifdef KRB4
952	use_v4 = 0;
953#endif
954#ifdef KRB5
955	use_v5 = 0;
956#endif
957    }
958
959    if(priv_socket1 < 0) {
960	if (use_only_broken)
961	    errx (1, "unable to bind reserved port: is rsh setuid root?");
962	use_broken = 0;
963    }
964
965#if defined(KRB4) || defined(KRB5)
966    if (do_encrypt == 1 && use_only_broken)
967	errx (1, "encryption not supported with old style authentication");
968#endif
969
970
971
972#ifdef KRB5
973    if (do_unique_tkfile && unique_tkfile != NULL)
974	errx (1, "Only one of -u and -U allowed.");
975
976    if (do_unique_tkfile)
977	strcpy(tkfile,"-u ");
978    else if (unique_tkfile != NULL) {
979	if (strchr(unique_tkfile,' ') != NULL) {
980	    warnx("Space is not allowed in tkfilename");
981	    usage(1);
982	}
983	do_unique_tkfile = 1;
984	snprintf (tkfile, sizeof(tkfile), "-U %s ", unique_tkfile);
985    }
986#endif
987
988    if (host == NULL) {
989	if (argc - optind < 1)
990	    usage (1);
991	else
992	    host = argv[host_index = optind++];
993    }
994
995    if((tmp = strchr(host, '@')) != NULL) {
996	*tmp++ = '\0';
997	user = host;
998	host = tmp;
999    }
1000
1001    if (optind == argc) {
1002	close (priv_socket1);
1003	close (priv_socket2);
1004	argv[0] = "rlogin";
1005	execvp ("rlogin", argv);
1006	err (1, "execvp rlogin");
1007    }
1008
1009    local_user = get_default_username ();
1010    if (local_user == NULL)
1011	errx (1, "who are you?");
1012
1013    if (user == NULL)
1014	user = local_user;
1015
1016    cmd_len = construct_command(&cmd, argc - optind, argv + optind);
1017
1018    /*
1019     * Try all different authentication methods
1020     */
1021
1022#ifdef KRB5
1023    if (ret && use_v5) {
1024	memset (&hints, 0, sizeof(hints));
1025	hints.ai_socktype = SOCK_STREAM;
1026	hints.ai_protocol = IPPROTO_TCP;
1027
1028	if(port_str == NULL) {
1029	    error = getaddrinfo(host, "kshell", &hints, &ai);
1030	    if(error == EAI_NONAME)
1031		error = getaddrinfo(host, "544", &hints, &ai);
1032	} else
1033	    error = getaddrinfo(host, port_str, &hints, &ai);
1034
1035	if(error)
1036	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1037
1038	auth_method = AUTH_KRB5;
1039      again:
1040	ret = doit (host, ai, user, local_user, cmd, cmd_len,
1041		    do_errsock,
1042		    send_krb5_auth);
1043	if(ret != 0 && sendauth_version_error &&
1044	   protocol_version == 2) {
1045	    protocol_version = 1;
1046	    goto again;
1047	}
1048	freeaddrinfo(ai);
1049    }
1050#endif
1051#ifdef KRB4
1052    if (ret && use_v4) {
1053	memset (&hints, 0, sizeof(hints));
1054	hints.ai_socktype = SOCK_STREAM;
1055	hints.ai_protocol = IPPROTO_TCP;
1056
1057	if(port_str == NULL) {
1058	    if(do_encrypt) {
1059		error = getaddrinfo(host, "ekshell", &hints, &ai);
1060		if(error == EAI_NONAME)
1061		    error = getaddrinfo(host, "545", &hints, &ai);
1062	    } else {
1063		error = getaddrinfo(host, "kshell", &hints, &ai);
1064		if(error == EAI_NONAME)
1065		    error = getaddrinfo(host, "544", &hints, &ai);
1066	    }
1067	} else
1068	    error = getaddrinfo(host, port_str, &hints, &ai);
1069
1070	if(error)
1071	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1072	auth_method = AUTH_KRB4;
1073	ret = doit (host, ai, user, local_user, cmd, cmd_len,
1074		    do_errsock,
1075		    send_krb4_auth);
1076	freeaddrinfo(ai);
1077    }
1078#endif
1079    if (ret && use_broken) {
1080	memset (&hints, 0, sizeof(hints));
1081	hints.ai_socktype = SOCK_STREAM;
1082	hints.ai_protocol = IPPROTO_TCP;
1083
1084	if(port_str == NULL) {
1085	    error = getaddrinfo(host, "shell", &hints, &ai);
1086	    if(error == EAI_NONAME)
1087		error = getaddrinfo(host, "514", &hints, &ai);
1088	} else
1089	    error = getaddrinfo(host, port_str, &hints, &ai);
1090
1091	if(error)
1092	    errx (1, "getaddrinfo: %s", gai_strerror(error));
1093
1094	auth_method = AUTH_BROKEN;
1095	ret = doit_broken (argc, argv, host_index, ai,
1096			   user, local_user,
1097			   priv_socket1,
1098			   do_errsock ? priv_socket2 : -1,
1099			   cmd, cmd_len);
1100	freeaddrinfo(ai);
1101    }
1102    free(cmd);
1103    return ret;
1104}
1105