1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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/*
35 * Copyright (C) 1990 by the Massachusetts Institute of Technology
36 *
37 * Export of this software from the United States of America may
38 * require a specific license from the United States Government.
39 * It is the responsibility of any person or organization contemplating
40 * export to obtain such a license before exporting.
41 *
42 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
43 * distribute this software and its documentation for any purpose and
44 * without fee is hereby granted, provided that the above copyright
45 * notice appear in all copies and that both that copyright notice and
46 * this permission notice appear in supporting documentation, and that
47 * the name of M.I.T. not be used in advertising or publicity pertaining
48 * to distribution of the software without specific, written prior
49 * permission.  M.I.T. makes no representations about the suitability of
50 * this software for any purpose.  It is provided "as is" without express
51 * or implied warranty.
52 */
53
54#include <config.h>
55
56RCSID("$Id$");
57
58#ifdef	KRB5
59
60#include <arpa/telnet.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <unistd.h>
65#include <netdb.h>
66#include <ctype.h>
67#include <pwd.h>
68#define Authenticator k5_Authenticator
69#include <krb5.h>
70#undef Authenticator
71#include <roken.h>
72#ifdef SOCKS
73#include <socks.h>
74#endif
75
76
77#include "encrypt.h"
78#include "auth.h"
79#include "misc.h"
80
81#if defined(DCE)
82int dfsk5ok = 0;
83int dfspag = 0;
84int dfsfwd = 0;
85#endif
86
87int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */
88
89int forward(int);
90int forwardable(int);
91
92/* These values need to be the same as those defined in telnet/main.c. */
93/* Either define them in both places, or put in some common header file. */
94#define OPTS_FORWARD_CREDS	0x00000002
95#define OPTS_FORWARDABLE_CREDS	0x00000001
96
97
98void kerberos5_forward (Authenticator *);
99
100static unsigned char str_data[4] = { IAC, SB, TELOPT_AUTHENTICATION, 0 };
101
102#define	KRB_AUTH		0	/* Authentication data follows */
103#define	KRB_REJECT		1	/* Rejected (reason might follow) */
104#define	KRB_ACCEPT		2	/* Accepted */
105#define	KRB_RESPONSE		3	/* Response for mutual auth. */
106
107#define KRB_FORWARD     	4       /* Forwarded credentials follow */
108#define KRB_FORWARD_ACCEPT     	5       /* Forwarded credentials accepted */
109#define KRB_FORWARD_REJECT     	6       /* Forwarded credentials rejected */
110
111static	krb5_data auth;
112static  krb5_ticket *ticket;
113
114static krb5_context context;
115static krb5_auth_context auth_context;
116
117static int
118Data(Authenticator *ap, int type, const void *d, int c)
119{
120    const unsigned char *cp, *cd = d;
121    unsigned char *p0, *p;
122    size_t len = sizeof(str_data) + 3 + 2;
123    int ret;
124
125    if (c == -1)
126	c = strlen((const char*)cd);
127
128    for (cp = cd; cp - cd < c; cp++, len++)
129	if (*cp == IAC)
130	    len++;
131
132    p0 = malloc(len);
133    if (p0 == NULL)
134	return 0;
135
136    memcpy(p0, str_data, sizeof(str_data));
137    p = p0 + sizeof(str_data);
138
139    if (auth_debug_mode) {
140	printf("%s:%d: [%d] (%d)",
141	       str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
142	       str_data[3],
143	       type, c);
144	printd(d, c);
145	printf("\r\n");
146    }
147    *p++ = ap->type;
148    *p++ = ap->way;
149    *p++ = type;
150    while (c-- > 0) {
151	if ((*p++ = *cd++) == IAC)
152	    *p++ = IAC;
153    }
154    *p++ = IAC;
155    *p++ = SE;
156    if (str_data[3] == TELQUAL_IS)
157	printsub('>', &p0[2], len - 2);
158    ret = telnet_net_write(p0, len);
159    free(p0);
160    return ret;
161}
162
163int
164kerberos5_init(Authenticator *ap, int server)
165{
166    krb5_error_code ret;
167
168    ret = krb5_init_context(&context);
169    if (ret)
170	return 0;
171    if (server) {
172	krb5_keytab kt;
173	krb5_kt_cursor cursor;
174
175	ret = krb5_kt_default(context, &kt);
176	if (ret)
177	    return 0;
178
179	ret = krb5_kt_start_seq_get (context, kt, &cursor);
180	if (ret) {
181	    krb5_kt_close (context, kt);
182	    return 0;
183	}
184	krb5_kt_end_seq_get (context, kt, &cursor);
185	krb5_kt_close (context, kt);
186
187	str_data[3] = TELQUAL_REPLY;
188    } else
189	str_data[3] = TELQUAL_IS;
190    return(1);
191}
192
193extern int net;
194static int
195kerberos5_send(char *name, Authenticator *ap)
196{
197    krb5_error_code ret;
198    krb5_ccache ccache;
199    int ap_opts;
200    krb5_data cksum_data;
201    char ap_msg[2];
202
203    if (!UserNameRequested) {
204	if (auth_debug_mode) {
205	    printf("Kerberos V5: no user name supplied\r\n");
206	}
207	return(0);
208    }
209
210    ret = krb5_cc_default(context, &ccache);
211    if (ret) {
212	if (auth_debug_mode) {
213	    printf("Kerberos V5: could not get default ccache: %s\r\n",
214		   krb5_get_err_text (context, ret));
215	}
216	return 0;
217    }
218
219    if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
220	ap_opts = AP_OPTS_MUTUAL_REQUIRED;
221    else
222	ap_opts = 0;
223
224    ap_opts |= AP_OPTS_USE_SUBKEY;
225
226    ret = krb5_auth_con_init (context, &auth_context);
227    if (ret) {
228	if (auth_debug_mode) {
229	    printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
230		   krb5_get_err_text(context, ret));
231	}
232	return(0);
233    }
234
235    ret = krb5_auth_con_setaddrs_from_fd (context,
236					  auth_context,
237					  &net);
238    if (ret) {
239	if (auth_debug_mode) {
240	    printf ("Kerberos V5:"
241		    " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
242		    krb5_get_err_text(context, ret));
243	}
244	return(0);
245    }
246
247    krb5_auth_con_setkeytype (context, auth_context, KRB5_ENCTYPE_DES_CBC_CRC);
248
249    ap_msg[0] = ap->type;
250    ap_msg[1] = ap->way;
251
252    cksum_data.length = sizeof(ap_msg);
253    cksum_data.data   = ap_msg;
254
255
256    {
257	krb5_principal service;
258	char sname[128];
259
260
261	ret = krb5_sname_to_principal (context,
262				       RemoteHostName,
263				       NULL,
264				       KRB5_NT_SRV_HST,
265				       &service);
266	if(ret) {
267	    if (auth_debug_mode) {
268		printf ("Kerberos V5:"
269			" krb5_sname_to_principal(%s) failed (%s)\r\n",
270			RemoteHostName, krb5_get_err_text(context, ret));
271	    }
272	    return 0;
273	}
274	ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
275	if(ret) {
276	    if (auth_debug_mode) {
277		printf ("Kerberos V5:"
278			" krb5_unparse_name_fixed failed (%s)\r\n",
279			krb5_get_err_text(context, ret));
280	    }
281	    return 0;
282	}
283	printf("[ Trying %s (%s)... ]\r\n", name, sname);
284	ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
285				service,
286				&cksum_data, ccache, &auth);
287	krb5_free_principal (context, service);
288
289    }
290    if (ret) {
291	if (1 || auth_debug_mode) {
292	    printf("Kerberos V5: mk_req failed (%s)\r\n",
293		   krb5_get_err_text(context, ret));
294	}
295	return(0);
296    }
297
298    if (!auth_sendname((unsigned char *)UserNameRequested,
299		       strlen(UserNameRequested))) {
300	if (auth_debug_mode)
301	    printf("Not enough room for user name\r\n");
302	return(0);
303    }
304    if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
305	if (auth_debug_mode)
306	    printf("Not enough room for authentication data\r\n");
307	return(0);
308    }
309    if (auth_debug_mode) {
310	printf("Sent Kerberos V5 credentials to server\r\n");
311    }
312    return(1);
313}
314
315int
316kerberos5_send_mutual(Authenticator *ap)
317{
318    return kerberos5_send("mutual KERBEROS5", ap);
319}
320
321int
322kerberos5_send_oneway(Authenticator *ap)
323{
324    return kerberos5_send("KERBEROS5", ap);
325}
326
327static void log_message(const char *fmt, ...)
328{
329    va_list ap;
330    va_start(ap, fmt);
331    if (auth_debug_mode) {
332	va_start(ap, fmt);
333	vfprintf(stdout, fmt, ap);
334	va_end(ap);
335	fprintf(stdout, "\r\n");
336    }
337    va_start(ap, fmt);
338    vsyslog(LOG_NOTICE, fmt, ap);
339    va_end(ap);
340}
341
342void
343kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
344{
345    krb5_error_code ret;
346    krb5_data outbuf;
347    krb5_keyblock *key_block;
348    char *name;
349    krb5_principal server;
350    int zero = 0;
351
352    if (cnt-- < 1)
353	return;
354    switch (*data++) {
355    case KRB_AUTH:
356	auth.data = (char *)data;
357	auth.length = cnt;
358
359	auth_context = NULL;
360
361	ret = krb5_auth_con_init (context, &auth_context);
362	if (ret) {
363	    Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
364	    auth_finished(ap, AUTH_REJECT);
365	    log_message("Kerberos V5: krb5_auth_con_init failed (%s)",
366			krb5_get_err_text(context, ret));
367	    return;
368	}
369
370	ret = krb5_auth_con_setaddrs_from_fd (context,
371					      auth_context,
372					      &zero);
373	if (ret) {
374	    Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
375	    auth_finished(ap, AUTH_REJECT);
376	    log_message("Kerberos V5: "
377			"krb5_auth_con_setaddrs_from_fd failed (%s)",
378			krb5_get_err_text(context, ret));
379	    return;
380	}
381
382	ret = krb5_sock_to_principal (context,
383				      0,
384				      "host",
385				      KRB5_NT_SRV_HST,
386				      &server);
387	if (ret) {
388	    Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
389	    auth_finished(ap, AUTH_REJECT);
390	    log_message("Kerberos V5: "
391			"krb5_sock_to_principal failed (%s)",
392			krb5_get_err_text(context, ret));
393	    return;
394	}
395
396	ret = krb5_rd_req(context,
397			  &auth_context,
398			  &auth,
399			  server,
400			  NULL,
401			  NULL,
402			  &ticket);
403
404	krb5_free_principal (context, server);
405	if (ret) {
406	    const char *errbuf2 = "Read req failed";
407	    char *errbuf;
408	    int ret2;
409
410	    ret2 = asprintf(&errbuf,
411			    "Read req failed: %s",
412			    krb5_get_err_text(context, ret));
413	    if (ret2 != -1)
414		errbuf2 = errbuf;
415	    Data(ap, KRB_REJECT, errbuf2, -1);
416	    log_message("%s", errbuf2);
417	    if (ret2 != -1)
418		free (errbuf);
419	    return;
420	}
421
422	{
423	    char ap_msg[2];
424
425	    ap_msg[0] = ap->type;
426	    ap_msg[1] = ap->way;
427
428	    ret = krb5_verify_authenticator_checksum(context,
429						     auth_context,
430						     ap_msg,
431						     sizeof(ap_msg));
432
433	    if (ret) {
434		const char *errbuf2 = "Bad checksum";
435		char *errbuf;
436		int ret2;
437
438		ret2 = asprintf(&errbuf, "Bad checksum: %s",
439				krb5_get_err_text(context, ret));
440		if (ret2 != -1)
441		    errbuf2 = errbuf;
442		Data(ap, KRB_REJECT, errbuf2, -1);
443		log_message("%s", errbuf2);
444		if (ret2 != -1)
445		    free(errbuf);
446		return;
447	    }
448	}
449	ret = krb5_auth_con_getremotesubkey (context,
450					     auth_context,
451					     &key_block);
452
453	if (ret) {
454	    Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
455	    auth_finished(ap, AUTH_REJECT);
456	    log_message("Kerberos V5: "
457			"krb5_auth_con_getremotesubkey failed (%s)",
458			krb5_get_err_text(context, ret));
459	    return;
460	}
461
462	if (key_block == NULL) {
463	    ret = krb5_auth_con_getkey(context,
464				       auth_context,
465				       &key_block);
466	}
467	if (ret) {
468	    Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
469	    auth_finished(ap, AUTH_REJECT);
470	    log_message("Kerberos V5: "
471			"krb5_auth_con_getkey failed (%s)",
472			krb5_get_err_text(context, ret));
473	    return;
474	}
475	if (key_block == NULL) {
476	    Data(ap, KRB_REJECT, "no subkey received", -1);
477	    auth_finished(ap, AUTH_REJECT);
478	    log_message("Kerberos V5: "
479			"krb5_auth_con_getremotesubkey returned NULL key");
480	    return;
481	}
482
483	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
484	    ret = krb5_mk_rep(context, auth_context, &outbuf);
485	    if (ret) {
486		Data(ap, KRB_REJECT,
487		     "krb5_mk_rep failed", -1);
488		auth_finished(ap, AUTH_REJECT);
489		log_message("Kerberos V5: "
490			    "krb5_mk_rep failed (%s)",
491			    krb5_get_err_text(context, ret));
492		krb5_free_keyblock(context, key_block);
493		return;
494	    }
495	    Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
496	}
497	if (krb5_unparse_name(context, ticket->client, &name))
498	    name = 0;
499
500	if(UserNameRequested && krb5_kuserok(context,
501					     ticket->client,
502					     UserNameRequested)) {
503	    Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
504	    log_message("%s accepted as user %s from %s",
505			name ? name : "<unknown>",
506			UserNameRequested ? UserNameRequested : "<unknown>",
507			RemoteHostName ? RemoteHostName : "<unknown>");
508
509	    if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
510	       key_block->keytype == ETYPE_DES_CBC_MD4 ||
511	       key_block->keytype == ETYPE_DES_CBC_CRC) {
512		Session_Key skey;
513
514		skey.type = SK_DES;
515		skey.length = 8;
516		skey.data = key_block->keyvalue.data;
517		encrypt_session_key(&skey, 0);
518	    }
519
520	} else {
521	    const char *msg2 = "user is not authorized to login";
522	    char *msg;
523
524	    ret = asprintf (&msg, "user `%s' is not authorized to "
525			    "login as `%s'",
526			    name ? name : "<unknown>",
527			    UserNameRequested ? UserNameRequested : "<nobody>");
528	    if (ret != -1)
529		msg2 = msg;
530	    Data(ap, KRB_REJECT, (void *)msg2, -1);
531	    if (ret != -1)
532		free(msg);
533	    auth_finished (ap, AUTH_REJECT);
534	    krb5_free_keyblock(context, key_block);
535	    break;
536	}
537	auth_finished(ap, AUTH_USER);
538	krb5_free_keyblock(context, key_block);
539
540	break;
541    case KRB_FORWARD: {
542	struct passwd *pwd;
543	char ccname[1024];	/* XXX */
544	krb5_data inbuf;
545	krb5_ccache ccache;
546	inbuf.data = (char *)data;
547	inbuf.length = cnt;
548
549	pwd = getpwnam (UserNameRequested);
550	if (pwd == NULL)
551	    break;
552
553	snprintf (ccname, sizeof(ccname),
554		  "FILE:/tmp/krb5cc_%lu", (unsigned long)pwd->pw_uid);
555
556	ret = krb5_cc_resolve (context, ccname, &ccache);
557	if (ret) {
558	    log_message("Kerberos V5: could not get ccache: %s",
559			krb5_get_err_text(context, ret));
560	    break;
561	}
562
563	ret = krb5_cc_initialize (context,
564				  ccache,
565				  ticket->client);
566	if (ret) {
567	    log_message("Kerberos V5: could not init ccache: %s",
568			krb5_get_err_text(context, ret));
569	    break;
570	}
571
572#if defined(DCE)
573	esetenv("KRB5CCNAME", ccname, 1);
574#endif
575	ret = krb5_rd_cred2 (context,
576			     auth_context,
577			     ccache,
578			     &inbuf);
579	if(ret) {
580	    const char *errbuf2 = "Read forwarded creds failed";
581	    char *errbuf;
582	    int ret2;
583
584	    ret2 = asprintf (&errbuf,
585			     "Read forwarded creds failed: %s",
586			     krb5_get_err_text (context, ret));
587	    if (ret2 != -1)
588		errbuf2 = errbuf;
589	    Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
590	    log_message("Could not read forwarded credentials: %s", errbuf);
591
592	    if (ret2 != -1)
593		free (errbuf);
594	} else {
595	    Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
596#if defined(DCE)
597	    dfsfwd = 1;
598#endif
599	}
600	chown (ccname + 5, pwd->pw_uid, -1);
601	log_message("Forwarded credentials obtained");
602	break;
603    }
604    default:
605	log_message("Unknown Kerberos option %d", data[-1]);
606	Data(ap, KRB_REJECT, 0, 0);
607	break;
608    }
609}
610
611void
612kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
613{
614    static int mutual_complete = 0;
615
616    if (cnt-- < 1)
617	return;
618    switch (*data++) {
619    case KRB_REJECT:
620	if (cnt > 0) {
621	    printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
622		   cnt, data);
623	} else
624	    printf("[ Kerberos V5 refuses authentication ]\r\n");
625	auth_send_retry();
626	return;
627    case KRB_ACCEPT: {
628	krb5_error_code ret;
629	Session_Key skey;
630	krb5_keyblock *keyblock;
631
632	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
633	    !mutual_complete) {
634	    printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
635	    auth_send_retry();
636	    return;
637	}
638	if (cnt)
639	    printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
640	else
641	    printf("[ Kerberos V5 accepts you ]\r\n");
642
643	ret = krb5_auth_con_getlocalsubkey (context,
644					    auth_context,
645					    &keyblock);
646	if (ret)
647	    ret = krb5_auth_con_getkey (context,
648					auth_context,
649					&keyblock);
650	if(ret) {
651	    printf("[ krb5_auth_con_getkey: %s ]\r\n",
652		   krb5_get_err_text(context, ret));
653	    auth_send_retry();
654	    return;
655	}
656
657	skey.type = SK_DES;
658	skey.length = 8;
659	skey.data = keyblock->keyvalue.data;
660	encrypt_session_key(&skey, 0);
661	krb5_free_keyblock (context, keyblock);
662	auth_finished(ap, AUTH_USER);
663	if (forward_flags & OPTS_FORWARD_CREDS)
664	    kerberos5_forward(ap);
665	break;
666    }
667    case KRB_RESPONSE:
668	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
669	    /* the rest of the reply should contain a krb_ap_rep */
670	  krb5_ap_rep_enc_part *reply;
671	  krb5_data inbuf;
672	  krb5_error_code ret;
673
674	  inbuf.length = cnt;
675	  inbuf.data = (char *)data;
676
677	  ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
678	  if (ret) {
679	      printf("[ Mutual authentication failed: %s ]\r\n",
680		     krb5_get_err_text (context, ret));
681	      auth_send_retry();
682	      return;
683	  }
684	  krb5_free_ap_rep_enc_part(context, reply);
685	  mutual_complete = 1;
686	}
687	return;
688    case KRB_FORWARD_ACCEPT:
689	printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
690	return;
691    case KRB_FORWARD_REJECT:
692	printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
693	       cnt, data);
694	return;
695    default:
696	if (auth_debug_mode)
697	    printf("Unknown Kerberos option %d\r\n", data[-1]);
698	return;
699    }
700}
701
702int
703kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
704{
705    if (level < AUTH_USER)
706	return(level);
707
708    if (UserNameRequested &&
709	krb5_kuserok(context,
710		     ticket->client,
711		     UserNameRequested))
712	{
713	    strlcpy(name, UserNameRequested, name_sz);
714#if defined(DCE)
715	    dfsk5ok = 1;
716#endif
717	    return(AUTH_VALID);
718	} else
719	    return(AUTH_USER);
720}
721
722#define	BUMP(buf, len)		while (*(buf)) {++(buf), --(len);}
723#define	ADDC(buf, len, c)	if ((len) > 0) {*(buf)++ = (c); --(len);}
724
725void
726kerberos5_printsub(unsigned char *data, size_t cnt,
727		   unsigned char *buf, size_t buflen)
728{
729    int i;
730
731    buf[buflen-1] = '\0';		/* make sure it's NULL terminated */
732    buflen -= 1;
733
734    switch(data[3]) {
735    case KRB_REJECT:		/* Rejected (reason might follow) */
736	strlcpy((char *)buf, " REJECT ", buflen);
737	goto common;
738
739    case KRB_ACCEPT:		/* Accepted (name might follow) */
740	strlcpy((char *)buf, " ACCEPT ", buflen);
741    common:
742	BUMP(buf, buflen);
743	if (cnt <= 4)
744	    break;
745	ADDC(buf, buflen, '"');
746	for (i = 4; i < cnt; i++)
747	    ADDC(buf, buflen, data[i]);
748	ADDC(buf, buflen, '"');
749	ADDC(buf, buflen, '\0');
750	break;
751
752
753    case KRB_AUTH:			/* Authentication data follows */
754	strlcpy((char *)buf, " AUTH", buflen);
755	goto common2;
756
757    case KRB_RESPONSE:
758	strlcpy((char *)buf, " RESPONSE", buflen);
759	goto common2;
760
761    case KRB_FORWARD:		/* Forwarded credentials follow */
762	strlcpy((char *)buf, " FORWARD", buflen);
763	goto common2;
764
765    case KRB_FORWARD_ACCEPT:	/* Forwarded credentials accepted */
766	strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
767	goto common2;
768
769    case KRB_FORWARD_REJECT:	/* Forwarded credentials rejected */
770	/* (reason might follow) */
771	strlcpy((char *)buf, " FORWARD_REJECT", buflen);
772	goto common2;
773
774    default:
775	snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
776    common2:
777	BUMP(buf, buflen);
778	for (i = 4; i < cnt; i++) {
779	    snprintf((char*)buf, buflen, " %d", data[i]);
780	    BUMP(buf, buflen);
781	}
782	break;
783    }
784}
785
786void
787kerberos5_forward(Authenticator *ap)
788{
789    krb5_error_code ret;
790    krb5_ccache     ccache;
791    krb5_creds      creds;
792    KDCOptions	    flags;
793    krb5_data       out_data;
794    krb5_principal  principal;
795
796    ret = krb5_cc_default (context, &ccache);
797    if (ret) {
798	if (auth_debug_mode)
799	    printf ("KerberosV5: could not get default ccache: %s\r\n",
800		    krb5_get_err_text (context, ret));
801	return;
802    }
803
804    ret = krb5_cc_get_principal (context, ccache, &principal);
805    if (ret) {
806	if (auth_debug_mode)
807	    printf ("KerberosV5: could not get principal: %s\r\n",
808		    krb5_get_err_text (context, ret));
809	return;
810    }
811
812    memset (&creds, 0, sizeof(creds));
813
814    creds.client = principal;
815
816    ret = krb5_make_principal(context,
817			      &creds.server,
818			      principal->realm,
819			      "krbtgt",
820			      principal->realm,
821			      NULL);
822
823    if (ret) {
824	if (auth_debug_mode)
825	    printf ("KerberosV5: could not get principal: %s\r\n",
826		    krb5_get_err_text (context, ret));
827	return;
828    }
829
830    creds.times.endtime = 0;
831
832    memset(&flags, 0, sizeof(flags));
833    flags.forwarded = 1;
834    if (forward_flags & OPTS_FORWARDABLE_CREDS)
835	flags.forwardable = 1;
836
837    ret = krb5_get_forwarded_creds (context,
838				    auth_context,
839				    ccache,
840				    KDCOptions2int(flags),
841				    RemoteHostName,
842				    &creds,
843				    &out_data);
844    if (ret) {
845	if (auth_debug_mode)
846	    printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
847		    krb5_get_err_text (context, ret));
848	return;
849    }
850
851    if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
852	if (auth_debug_mode)
853	    printf("Not enough room for authentication data\r\n");
854    } else {
855	if (auth_debug_mode)
856	    printf("Forwarded local Kerberos V5 credentials to server\r\n");
857    }
858}
859
860#if defined(DCE)
861/* if this was a K5 authentication try and join a PAG for the user. */
862void
863kerberos5_dfspag(void)
864{
865    if (dfsk5ok) {
866	dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
867			      UserNameRequested);
868    }
869}
870#endif
871
872int
873kerberos5_set_forward(int on)
874{
875    if(on == 0)
876	forward_flags &= ~OPTS_FORWARD_CREDS;
877    if(on == 1)
878	forward_flags |= OPTS_FORWARD_CREDS;
879    if(on == -1)
880	forward_flags ^= OPTS_FORWARD_CREDS;
881    return 0;
882}
883
884int
885kerberos5_set_forwardable(int on)
886{
887    if(on == 0)
888	forward_flags &= ~OPTS_FORWARDABLE_CREDS;
889    if(on == 1)
890	forward_flags |= OPTS_FORWARDABLE_CREDS;
891    if(on == -1)
892	forward_flags ^= OPTS_FORWARDABLE_CREDS;
893    return 0;
894}
895
896#endif /* KRB5 */
897