kerberos5.c revision 90931 
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 <sys/cdefs.h>
55
56__FBSDID("$FreeBSD: head/contrib/telnet/libtelnet/kerberos5.c 90931 2002-02-19 15:53:33Z nectar $");
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
72#include "encrypt.h"
73#include "auth.h"
74#include "misc.h"
75
76int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */
77
78/* These values need to be the same as those defined in telnet/main.c. */
79/* Either define them in both places, or put in some common header file. */
80#define OPTS_FORWARD_CREDS	0x00000002
81#define OPTS_FORWARDABLE_CREDS	0x00000001
82
83void kerberos5_forward (Authenticator *);
84
85static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
86			  		AUTHTYPE_KERBEROS_V5, };
87
88#define	KRB_AUTH		0	/* Authentication data follows */
89#define	KRB_REJECT		1	/* Rejected (reason might follow) */
90#define	KRB_ACCEPT		2	/* Accepted */
91#define	KRB_RESPONSE		3	/* Response for mutual auth. */
92
93#define KRB_FORWARD     	4       /* Forwarded credentials follow */
94#define KRB_FORWARD_ACCEPT     	5       /* Forwarded credentials accepted */
95#define KRB_FORWARD_REJECT     	6       /* Forwarded credentials rejected */
96
97static	krb5_data auth;
98static  krb5_ticket *ticket;
99
100static krb5_context context;
101static krb5_auth_context auth_context;
102
103static int
104Data(Authenticator *ap, int type, const char *d, int c)
105{
106    unsigned char *p = str_data + 4;
107    const unsigned char *cd = d;
108
109    if (c == -1)
110	c = strlen(cd);
111
112    if (auth_debug_mode) {
113	printf("%s:%d: [%d] (%d)",
114	       str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
115	       str_data[3],
116	       type, c);
117	printd(d, c);
118	printf("\r\n");
119    }
120    *p++ = ap->type;
121    *p++ = ap->way;
122    *p++ = type;
123    while (c-- > 0) {
124	if ((*p++ = *cd++) == IAC)
125	    *p++ = IAC;
126    }
127    *p++ = IAC;
128    *p++ = SE;
129    if (str_data[3] == TELQUAL_IS)
130	printsub('>', &str_data[2], p - &str_data[2]);
131    return(net_write(str_data, p - str_data));
132}
133
134int
135kerberos5_init(Authenticator *ap __unused, int server)
136{
137    krb5_error_code ret;
138
139    ret = krb5_init_context(&context);
140    if (ret)
141	return 0;
142    if (server) {
143	krb5_keytab kt;
144	krb5_kt_cursor cursor;
145
146	ret = krb5_kt_default(context, &kt);
147	if (ret)
148	    return 0;
149
150	ret = krb5_kt_start_seq_get (context, kt, &cursor);
151	if (ret) {
152	    krb5_kt_close (context, kt);
153	    return 0;
154	}
155	krb5_kt_end_seq_get (context, kt, &cursor);
156	krb5_kt_close (context, kt);
157
158	str_data[3] = TELQUAL_REPLY;
159    } else
160	str_data[3] = TELQUAL_IS;
161    return(1);
162}
163
164extern int net;
165
166static int
167kerberos5_send(const char *name, Authenticator *ap)
168{
169    krb5_error_code ret;
170    krb5_ccache ccache;
171    int ap_opts;
172    krb5_data cksum_data;
173    char foo[2];
174
175    if (!UserNameRequested) {
176	if (auth_debug_mode) {
177	    printf("Kerberos V5: no user name supplied\r\n");
178	}
179	return(0);
180    }
181
182    ret = krb5_cc_default(context, &ccache);
183    if (ret) {
184	if (auth_debug_mode) {
185	    printf("Kerberos V5: could not get default ccache: %s\r\n",
186		   krb5_get_err_text (context, ret));
187	}
188	return 0;
189    }
190
191    if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
192	ap_opts = AP_OPTS_MUTUAL_REQUIRED;
193    else
194	ap_opts = 0;
195
196    ret = krb5_auth_con_init (context, &auth_context);
197    if (ret) {
198	if (auth_debug_mode) {
199	    printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
200		   krb5_get_err_text(context, ret));
201	}
202	return(0);
203    }
204
205    ret = krb5_auth_con_setaddrs_from_fd (context,
206					  auth_context,
207					  &net);
208    if (ret) {
209	if (auth_debug_mode) {
210	    printf ("Kerberos V5:"
211		    " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
212		    krb5_get_err_text(context, ret));
213	}
214	return(0);
215    }
216
217    krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
218
219    foo[0] = ap->type;
220    foo[1] = ap->way;
221
222    cksum_data.length = sizeof(foo);
223    cksum_data.data   = foo;
224
225
226    {
227	krb5_principal service;
228	char sname[128];
229
230
231	ret = krb5_sname_to_principal (context,
232				       RemoteHostName,
233				       NULL,
234				       KRB5_NT_SRV_HST,
235				       &service);
236	if(ret) {
237	    if (auth_debug_mode) {
238		printf ("Kerberos V5:"
239			" krb5_sname_to_principal(%s) failed (%s)\r\n",
240			RemoteHostName, krb5_get_err_text(context, ret));
241	    }
242	    return 0;
243	}
244	ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
245	if(ret) {
246	    if (auth_debug_mode) {
247		printf ("Kerberos V5:"
248			" krb5_unparse_name_fixed failed (%s)\r\n",
249			krb5_get_err_text(context, ret));
250	    }
251	    return 0;
252	}
253	printf("[ Trying %s (%s)... ]\r\n", name, sname);
254	ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
255				service,
256				&cksum_data, ccache, &auth);
257	krb5_free_principal (context, service);
258
259    }
260    if (ret) {
261	if (1 || auth_debug_mode) {
262	    printf("Kerberos V5: mk_req failed (%s)\r\n",
263		   krb5_get_err_text(context, ret));
264	}
265	return(0);
266    }
267
268    if (!auth_sendname((unsigned char *)UserNameRequested,
269		       strlen(UserNameRequested))) {
270	if (auth_debug_mode)
271	    printf("Not enough room for user name\r\n");
272	return(0);
273    }
274    if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
275	if (auth_debug_mode)
276	    printf("Not enough room for authentication data\r\n");
277	return(0);
278    }
279    if (auth_debug_mode) {
280	printf("Sent Kerberos V5 credentials to server\r\n");
281    }
282    return(1);
283}
284
285int
286kerberos5_send_mutual(Authenticator *ap)
287{
288    return kerberos5_send("mutual KERBEROS5", ap);
289}
290
291int
292kerberos5_send_oneway(Authenticator *ap)
293{
294    return kerberos5_send("KERBEROS5", ap);
295}
296
297void
298kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
299{
300    krb5_error_code ret;
301    krb5_data outbuf;
302    krb5_keyblock *key_block;
303    char *name;
304    krb5_principal server;
305    int zero = 0;
306
307    if (cnt-- < 1)
308	return;
309    switch (*data++) {
310    case KRB_AUTH:
311	auth.data = (char *)data;
312	auth.length = cnt;
313
314	auth_context = NULL;
315
316	ret = krb5_auth_con_init (context, &auth_context);
317	if (ret) {
318	    Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
319	    auth_finished(ap, AUTH_REJECT);
320	    if (auth_debug_mode)
321		printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
322		       krb5_get_err_text(context, ret));
323	    return;
324	}
325
326	ret = krb5_auth_con_setaddrs_from_fd (context,
327					      auth_context,
328					      &zero);
329	if (ret) {
330	    Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
331	    auth_finished(ap, AUTH_REJECT);
332	    if (auth_debug_mode)
333		printf("Kerberos V5: "
334		       "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
335		       krb5_get_err_text(context, ret));
336	    return;
337	}
338
339	ret = krb5_sock_to_principal (context,
340				      0,
341				      "host",
342				      KRB5_NT_SRV_HST,
343				      &server);
344	if (ret) {
345	    Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
346	    auth_finished(ap, AUTH_REJECT);
347	    if (auth_debug_mode)
348		printf("Kerberos V5: "
349		       "krb5_sock_to_principal failed (%s)\r\n",
350		       krb5_get_err_text(context, ret));
351	    return;
352	}
353
354	ret = krb5_rd_req(context,
355			  &auth_context,
356			  &auth,
357			  server,
358			  NULL,
359			  NULL,
360			  &ticket);
361
362	krb5_free_principal (context, server);
363	if (ret) {
364	    char *errbuf;
365
366	    asprintf(&errbuf,
367		     "Read req failed: %s",
368		     krb5_get_err_text(context, ret));
369	    Data(ap, KRB_REJECT, errbuf, -1);
370	    if (auth_debug_mode)
371		printf("%s\r\n", errbuf);
372	    free (errbuf);
373	    return;
374	}
375
376	{
377	    char foo[2];
378
379	    foo[0] = ap->type;
380	    foo[1] = ap->way;
381
382	    ret = krb5_verify_authenticator_checksum(context,
383						     auth_context,
384						     foo,
385						     sizeof(foo));
386
387	    if (ret) {
388		char *errbuf;
389		asprintf(&errbuf, "Bad checksum: %s",
390			 krb5_get_err_text(context, ret));
391		Data(ap, KRB_REJECT, errbuf, -1);
392		if (auth_debug_mode)
393		    printf ("%s\r\n", errbuf);
394		free(errbuf);
395		return;
396	    }
397	}
398	ret = krb5_auth_con_getremotesubkey (context,
399					     auth_context,
400					     &key_block);
401
402	if (ret) {
403	    Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
404	    auth_finished(ap, AUTH_REJECT);
405	    if (auth_debug_mode)
406		printf("Kerberos V5: "
407		       "krb5_auth_con_getremotesubkey failed (%s)\r\n",
408		       krb5_get_err_text(context, ret));
409	    return;
410	}
411
412	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
413	    ret = krb5_mk_rep(context, auth_context, &outbuf);
414	    if (ret) {
415		Data(ap, KRB_REJECT,
416		     "krb5_mk_rep failed", -1);
417		auth_finished(ap, AUTH_REJECT);
418		if (auth_debug_mode)
419		    printf("Kerberos V5: "
420			   "krb5_mk_rep failed (%s)\r\n",
421			   krb5_get_err_text(context, ret));
422		return;
423	    }
424	    Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
425	}
426	if (krb5_unparse_name(context, ticket->client, &name))
427	    name = 0;
428
429	if(UserNameRequested && krb5_kuserok(context,
430					     ticket->client,
431					     UserNameRequested)) {
432	    Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
433	    if (auth_debug_mode) {
434		printf("Kerberos5 identifies him as ``%s''\r\n",
435		       name ? name : "");
436	    }
437
438	    if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
439	       key_block->keytype == ETYPE_DES_CBC_MD4 ||
440	       key_block->keytype == ETYPE_DES_CBC_CRC) {
441		Session_Key skey;
442
443		skey.type = SK_DES;
444		skey.length = 8;
445		skey.data = key_block->keyvalue.data;
446		encrypt_session_key(&skey, 0);
447	    }
448
449	} else {
450	    char *msg;
451
452	    asprintf (&msg, "user `%s' is not authorized to "
453		      "login as `%s'",
454		      name ? name : "<unknown>",
455		      UserNameRequested ? UserNameRequested : "<nobody>");
456	    if (msg == NULL)
457		Data(ap, KRB_REJECT, NULL, 0);
458	    else {
459		Data(ap, KRB_REJECT, (void *)msg, -1);
460		free(msg);
461	    }
462	    auth_finished (ap, AUTH_REJECT);
463	    krb5_free_keyblock_contents(context, key_block);
464	    break;
465	}
466	auth_finished(ap, AUTH_USER);
467	krb5_free_keyblock_contents(context, key_block);
468
469	break;
470    case KRB_FORWARD: {
471	struct passwd *pwd;
472	char ccname[1024];	/* XXX */
473	krb5_data inbuf;
474	krb5_ccache ccache;
475	inbuf.data = (char *)data;
476	inbuf.length = cnt;
477
478	pwd = getpwnam (UserNameRequested);
479	if (pwd == NULL)
480	    break;
481
482	snprintf (ccname, sizeof(ccname),
483		  "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
484
485	ret = krb5_cc_resolve (context, ccname, &ccache);
486	if (ret) {
487	    if (auth_debug_mode)
488		printf ("Kerberos V5: could not get ccache: %s\r\n",
489			krb5_get_err_text(context, ret));
490	    break;
491	}
492
493	ret = krb5_cc_initialize (context,
494				  ccache,
495				  ticket->client);
496	if (ret) {
497	    if (auth_debug_mode)
498		printf ("Kerberos V5: could not init ccache: %s\r\n",
499			krb5_get_err_text(context, ret));
500	    break;
501	}
502
503#if defined(DCE)
504	esetenv("KRB5CCNAME", ccname, 1);
505#endif
506	ret = krb5_rd_cred2 (context,
507			     auth_context,
508			     ccache,
509			     &inbuf);
510	if(ret) {
511	    char *errbuf;
512
513	    asprintf (&errbuf,
514		      "Read forwarded creds failed: %s",
515		      krb5_get_err_text (context, ret));
516	    if(errbuf == NULL)
517		Data(ap, KRB_FORWARD_REJECT, NULL, 0);
518	    else
519		Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
520	    if (auth_debug_mode)
521		printf("Could not read forwarded credentials: %s\r\n",
522		       errbuf);
523	    free (errbuf);
524	} else {
525	    Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
526#if defined(DCE)
527	    dfsfwd = 1;
528#endif
529	}
530	chown (ccname + 5, pwd->pw_uid, -1);
531	if (auth_debug_mode)
532	    printf("Forwarded credentials obtained\r\n");
533	break;
534    }
535    default:
536	if (auth_debug_mode)
537	    printf("Unknown Kerberos option %d\r\n", data[-1]);
538	Data(ap, KRB_REJECT, 0, 0);
539	break;
540    }
541}
542
543void
544kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
545{
546    static int mutual_complete = 0;
547
548    if (cnt-- < 1)
549	return;
550    switch (*data++) {
551    case KRB_REJECT:
552	if (cnt > 0) {
553	    printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
554		   cnt, data);
555	} else
556	    printf("[ Kerberos V5 refuses authentication ]\r\n");
557	auth_send_retry();
558	return;
559    case KRB_ACCEPT: {
560	krb5_error_code ret;
561	Session_Key skey;
562	krb5_keyblock *keyblock;
563
564	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
565	    !mutual_complete) {
566	    printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
567	    auth_send_retry();
568	    return;
569	}
570	if (cnt)
571	    printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
572	else
573	    printf("[ Kerberos V5 accepts you ]\r\n");
574
575	ret = krb5_auth_con_getlocalsubkey (context,
576					    auth_context,
577					    &keyblock);
578	if (ret)
579	    ret = krb5_auth_con_getkey (context,
580					auth_context,
581					&keyblock);
582	if(ret) {
583	    printf("[ krb5_auth_con_getkey: %s ]\r\n",
584		   krb5_get_err_text(context, ret));
585	    auth_send_retry();
586	    return;
587	}
588
589	skey.type = SK_DES;
590	skey.length = 8;
591	skey.data = keyblock->keyvalue.data;
592	encrypt_session_key(&skey, 0);
593	krb5_free_keyblock_contents (context, keyblock);
594	auth_finished(ap, AUTH_USER);
595	if (forward_flags & OPTS_FORWARD_CREDS)
596	    kerberos5_forward(ap);
597	break;
598    }
599    case KRB_RESPONSE:
600	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
601	    /* the rest of the reply should contain a krb_ap_rep */
602	  krb5_ap_rep_enc_part *reply;
603	  krb5_data inbuf;
604	  krb5_error_code ret;
605
606	  inbuf.length = cnt;
607	  inbuf.data = (char *)data;
608
609	  ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
610	  if (ret) {
611	      printf("[ Mutual authentication failed: %s ]\r\n",
612		     krb5_get_err_text (context, ret));
613	      auth_send_retry();
614	      return;
615	  }
616	  krb5_free_ap_rep_enc_part(context, reply);
617	  mutual_complete = 1;
618	}
619	return;
620    case KRB_FORWARD_ACCEPT:
621	printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
622	return;
623    case KRB_FORWARD_REJECT:
624	printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
625	       cnt, data);
626	return;
627    default:
628	if (auth_debug_mode)
629	    printf("Unknown Kerberos option %d\r\n", data[-1]);
630	return;
631    }
632}
633
634int
635kerberos5_status(Authenticator *ap __unused, char *name, int level)
636{
637    if (level < AUTH_USER)
638	return(level);
639
640    if (UserNameRequested &&
641	krb5_kuserok(context,
642		     ticket->client,
643		     UserNameRequested))
644	{
645	    strcpy(name, UserNameRequested);
646	    return(AUTH_VALID);
647	} else
648	    return(AUTH_USER);
649}
650
651#define	BUMP(buf, len)		while (*(buf)) {++(buf), --(len);}
652#define	ADDC(buf, len, c)	if ((len) > 0) {*(buf)++ = (c); --(len);}
653
654void
655kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
656{
657    int i;
658
659    buf[buflen-1] = '\0';		/* make sure its NULL terminated */
660    buflen -= 1;
661
662    switch(data[3]) {
663    case KRB_REJECT:		/* Rejected (reason might follow) */
664	strlcpy((char *)buf, " REJECT ", buflen);
665	goto common;
666
667    case KRB_ACCEPT:		/* Accepted (name might follow) */
668	strlcpy((char *)buf, " ACCEPT ", buflen);
669    common:
670	BUMP(buf, buflen);
671	if (cnt <= 4)
672	    break;
673	ADDC(buf, buflen, '"');
674	for (i = 4; i < cnt; i++)
675	    ADDC(buf, buflen, data[i]);
676	ADDC(buf, buflen, '"');
677	ADDC(buf, buflen, '\0');
678	break;
679
680
681    case KRB_AUTH:			/* Authentication data follows */
682	strlcpy((char *)buf, " AUTH", buflen);
683	goto common2;
684
685    case KRB_RESPONSE:
686	strlcpy((char *)buf, " RESPONSE", buflen);
687	goto common2;
688
689    case KRB_FORWARD:		/* Forwarded credentials follow */
690	strlcpy((char *)buf, " FORWARD", buflen);
691	goto common2;
692
693    case KRB_FORWARD_ACCEPT:	/* Forwarded credentials accepted */
694	strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
695	goto common2;
696
697    case KRB_FORWARD_REJECT:	/* Forwarded credentials rejected */
698	/* (reason might follow) */
699	strlcpy((char *)buf, " FORWARD_REJECT", buflen);
700	goto common2;
701
702    default:
703	snprintf(buf, buflen, " %d (unknown)", data[3]);
704    common2:
705	BUMP(buf, buflen);
706	for (i = 4; i < cnt; i++) {
707	    snprintf(buf, buflen, " %d", data[i]);
708	    BUMP(buf, buflen);
709	}
710	break;
711    }
712}
713
714void
715kerberos5_forward(Authenticator *ap)
716{
717    krb5_error_code ret;
718    krb5_ccache     ccache;
719    krb5_creds      creds;
720    krb5_kdc_flags  flags;
721    krb5_data       out_data;
722    krb5_principal  principal;
723
724    ret = krb5_cc_default (context, &ccache);
725    if (ret) {
726	if (auth_debug_mode)
727	    printf ("KerberosV5: could not get default ccache: %s\r\n",
728		    krb5_get_err_text (context, ret));
729	return;
730    }
731
732    ret = krb5_cc_get_principal (context, ccache, &principal);
733    if (ret) {
734	if (auth_debug_mode)
735	    printf ("KerberosV5: could not get principal: %s\r\n",
736		    krb5_get_err_text (context, ret));
737	return;
738    }
739
740    memset (&creds, 0, sizeof(creds));
741
742    creds.client = principal;
743
744    ret = krb5_build_principal (context,
745				&creds.server,
746				strlen(principal->realm),
747				principal->realm,
748				"krbtgt",
749				principal->realm,
750				NULL);
751
752    if (ret) {
753	if (auth_debug_mode)
754	    printf ("KerberosV5: could not get principal: %s\r\n",
755		    krb5_get_err_text (context, ret));
756	return;
757    }
758
759    creds.times.endtime = 0;
760
761    flags.i = 0;
762    flags.b.forwarded = 1;
763    if (forward_flags & OPTS_FORWARDABLE_CREDS)
764	flags.b.forwardable = 1;
765
766    ret = krb5_get_forwarded_creds (context,
767				    auth_context,
768				    ccache,
769				    flags.i,
770				    RemoteHostName,
771				    &creds,
772				    &out_data);
773    if (ret) {
774	if (auth_debug_mode)
775	    printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
776		    krb5_get_err_text (context, ret));
777	return;
778    }
779
780    if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
781	if (auth_debug_mode)
782	    printf("Not enough room for authentication data\r\n");
783    } else {
784	if (auth_debug_mode)
785	    printf("Forwarded local Kerberos V5 credentials to server\r\n");
786    }
787}
788
789#if defined(DCE)
790/* if this was a K5 authentication try and join a PAG for the user. */
791void
792kerberos5_dfspag(void)
793{
794    if (dfsk5ok) {
795	dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
796			      UserNameRequested);
797    }
798}
799#endif
800
801#endif /* KRB5 */
802