xref: /freebsd/contrib/telnet/libtelnet/kerberos5.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Copyright (C) 1990 by the Massachusetts Institute of Technology
32  *
33  * Export of this software from the United States of America may
34  * require a specific license from the United States Government.
35  * It is the responsibility of any person or organization contemplating
36  * export to obtain such a license before exporting.
37  *
38  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
39  * distribute this software and its documentation for any purpose and
40  * without fee is hereby granted, provided that the above copyright
41  * notice appear in all copies and that both that copyright notice and
42  * this permission notice appear in supporting documentation, and that
43  * the name of M.I.T. not be used in advertising or publicity pertaining
44  * to distribution of the software without specific, written prior
45  * permission.  M.I.T. makes no representations about the suitability of
46  * this software for any purpose.  It is provided "as is" without express
47  * or implied warranty.
48  */
49 
50 #include <sys/cdefs.h>
51 
52 __FBSDID("$FreeBSD$");
53 
54 #ifdef	KRB5
55 
56 #include <arpa/telnet.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <netdb.h>
62 #include <ctype.h>
63 #include <pwd.h>
64 #define Authenticator k5_Authenticator
65 #include <krb5.h>
66 #undef Authenticator
67 
68 #include "encrypt.h"
69 #include "auth.h"
70 #include "misc.h"
71 
72 int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */
73 
74 /* These values need to be the same as those defined in telnet/main.c. */
75 /* Either define them in both places, or put in some common header file. */
76 #define OPTS_FORWARD_CREDS	0x00000002
77 #define OPTS_FORWARDABLE_CREDS	0x00000001
78 
79 void kerberos5_forward (Authenticator *);
80 
81 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
82 			  		AUTHTYPE_KERBEROS_V5, };
83 
84 #define	KRB_AUTH		0	/* Authentication data follows */
85 #define	KRB_REJECT		1	/* Rejected (reason might follow) */
86 #define	KRB_ACCEPT		2	/* Accepted */
87 #define	KRB_RESPONSE		3	/* Response for mutual auth. */
88 
89 #define KRB_FORWARD     	4       /* Forwarded credentials follow */
90 #define KRB_FORWARD_ACCEPT     	5       /* Forwarded credentials accepted */
91 #define KRB_FORWARD_REJECT     	6       /* Forwarded credentials rejected */
92 
93 static	krb5_data auth;
94 static  krb5_ticket *ticket;
95 
96 static krb5_context context;
97 static krb5_auth_context auth_context;
98 
99 static void
100 print_krb5_error(krb5_context context, krb5_error_code code, const char *msg)
101 {
102 	const char *error_message;
103 
104 	error_message = krb5_get_error_message(context, code);
105 	printf(msg, error_message);
106 	krb5_free_error_message(context, error_message);
107 }
108 
109 static int
110 Data(Authenticator *ap, int type, const char *d, int c)
111 {
112     unsigned char *p = str_data + 4;
113     const unsigned char *cd = d;
114 
115     if (c == -1)
116 	c = strlen(cd);
117 
118     if (auth_debug_mode) {
119 	printf("%s:%d: [%d] (%d)",
120 	       str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
121 	       str_data[3],
122 	       type, c);
123 	printd(d, c);
124 	printf("\r\n");
125     }
126     *p++ = ap->type;
127     *p++ = ap->way;
128     *p++ = type;
129     while (c-- > 0) {
130 	if ((*p++ = *cd++) == IAC)
131 	    *p++ = IAC;
132     }
133     *p++ = IAC;
134     *p++ = SE;
135     if (str_data[3] == TELQUAL_IS)
136 	printsub('>', &str_data[2], p - &str_data[2]);
137     return(net_write(str_data, p - str_data));
138 }
139 
140 int
141 kerberos5_init(Authenticator *ap __unused, int server)
142 {
143     krb5_error_code ret;
144 
145     ret = krb5_init_context(&context);
146     if (ret)
147 	return 0;
148     if (server) {
149 	krb5_keytab kt;
150 	krb5_kt_cursor cursor;
151 
152 	ret = krb5_kt_default(context, &kt);
153 	if (ret)
154 	    return 0;
155 
156 	ret = krb5_kt_start_seq_get (context, kt, &cursor);
157 	if (ret) {
158 	    krb5_kt_close (context, kt);
159 	    return 0;
160 	}
161 	krb5_kt_end_seq_get (context, kt, &cursor);
162 	krb5_kt_close (context, kt);
163 
164 	str_data[3] = TELQUAL_REPLY;
165     } else
166 	str_data[3] = TELQUAL_IS;
167     return(1);
168 }
169 
170 extern int net;
171 
172 static int
173 kerberos5_send(const char *name, Authenticator *ap)
174 {
175     krb5_error_code ret;
176     krb5_ccache ccache;
177     int ap_opts;
178     krb5_data cksum_data;
179     char foo[2];
180 
181     if (!UserNameRequested) {
182 	if (auth_debug_mode) {
183 	    printf("Kerberos V5: no user name supplied\r\n");
184 	}
185 	return(0);
186     }
187 
188     ret = krb5_cc_default(context, &ccache);
189     if (ret) {
190 	if (auth_debug_mode) {
191 	    print_krb5_error(context, ret, "Kerberos V5: could not get default ccache: %s\r\n");
192 	}
193 	return 0;
194     }
195 
196     if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
197 	ap_opts = AP_OPTS_MUTUAL_REQUIRED;
198     else
199 	ap_opts = 0;
200     ap_opts |= AP_OPTS_USE_SUBKEY;
201 
202     ret = krb5_auth_con_init (context, &auth_context);
203     if (ret) {
204 	if (auth_debug_mode) {
205 	    print_krb5_error(context, ret, "Kerberos V5: krb5_auth_con_init failed (%s)\r\n");
206 	}
207 	return(0);
208     }
209 
210     ret = krb5_auth_con_setaddrs_from_fd (context,
211 					  auth_context,
212 					  &net);
213     if (ret) {
214 	if (auth_debug_mode) {
215 	    print_krb5_error(context, ret, "Kerberos V5:"
216 		    " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n");
217 	}
218 	return(0);
219     }
220 
221     krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
222 
223     foo[0] = ap->type;
224     foo[1] = ap->way;
225 
226     cksum_data.length = sizeof(foo);
227     cksum_data.data   = foo;
228 
229 
230     {
231 	krb5_principal service;
232 	char sname[128];
233 
234 
235 	ret = krb5_sname_to_principal (context,
236 				       RemoteHostName,
237 				       NULL,
238 				       KRB5_NT_SRV_HST,
239 				       &service);
240 	if(ret) {
241 	    if (auth_debug_mode) {
242 		const char *err_str;
243 
244 		err_str = krb5_get_error_message(context, ret);
245 		printf("Kerberosr V5:"
246 			" krb5_sname_to_principal(%s) failed (%s)\r\n",
247 			RemoteHostName, err_str);
248 		krb5_free_error_message(context, err_str);
249 	    }
250 	    return 0;
251 	}
252 	ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
253 	if(ret) {
254 	    if (auth_debug_mode) {
255 		print_krb5_error(context, ret, "Kerberos V5:"
256 			" krb5_unparse_name_fixed failed (%s)\r\n");
257 	    }
258 	    return 0;
259 	}
260 	printf("[ Trying %s (%s)... ]\r\n", name, sname);
261 	ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
262 				service,
263 				&cksum_data, ccache, &auth);
264 	krb5_free_principal (context, service);
265 
266     }
267     if (ret) {
268 	if (1 || auth_debug_mode) {
269 	    print_krb5_error(context, ret, "Kerberos V5: mk_req failed (%s)\r\n");
270 	}
271 	return(0);
272     }
273 
274     if (!auth_sendname((unsigned char *)UserNameRequested,
275 		       strlen(UserNameRequested))) {
276 	if (auth_debug_mode)
277 	    printf("Not enough room for user name\r\n");
278 	return(0);
279     }
280     if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
281 	if (auth_debug_mode)
282 	    printf("Not enough room for authentication data\r\n");
283 	return(0);
284     }
285     if (auth_debug_mode) {
286 	printf("Sent Kerberos V5 credentials to server\r\n");
287     }
288     return(1);
289 }
290 
291 int
292 kerberos5_send_mutual(Authenticator *ap)
293 {
294     return kerberos5_send("mutual KERBEROS5", ap);
295 }
296 
297 int
298 kerberos5_send_oneway(Authenticator *ap)
299 {
300     return kerberos5_send("KERBEROS5", ap);
301 }
302 
303 void
304 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
305 {
306     krb5_error_code ret;
307     krb5_data outbuf;
308     krb5_keyblock *key_block;
309     char *name;
310     krb5_principal server;
311     int zero = 0;
312 
313     if (cnt-- < 1)
314 	return;
315     switch (*data++) {
316     case KRB_AUTH:
317 	auth.data = (char *)data;
318 	auth.length = cnt;
319 
320 	auth_context = NULL;
321 
322 	ret = krb5_auth_con_init (context, &auth_context);
323 	if (ret) {
324 	    Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
325 	    auth_finished(ap, AUTH_REJECT);
326 	    if (auth_debug_mode)
327 		print_krb5_error(context, ret, "Kerberos V5: krb5_auth_con_init failed (%s)\r\n");
328 	    return;
329 	}
330 
331 	ret = krb5_auth_con_setaddrs_from_fd (context,
332 					      auth_context,
333 					      &zero);
334 	if (ret) {
335 	    Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
336 	    auth_finished(ap, AUTH_REJECT);
337 	    if (auth_debug_mode)
338 		print_krb5_error(context, ret, "Kerberos V5: "
339 		       "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n");
340 	    return;
341 	}
342 
343 	ret = krb5_sock_to_principal (context,
344 				      0,
345 				      "host",
346 				      KRB5_NT_SRV_HST,
347 				      &server);
348 	if (ret) {
349 	    Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
350 	    auth_finished(ap, AUTH_REJECT);
351 	    if (auth_debug_mode)
352 		print_krb5_error(context, ret, "Kerberos V5: "
353 		       "krb5_sock_to_principal failed (%s)\r\n");
354 	    return;
355 	}
356 
357 	ret = krb5_rd_req(context,
358 			  &auth_context,
359 			  &auth,
360 			  server,
361 			  NULL,
362 			  NULL,
363 			  &ticket);
364 
365 	krb5_free_principal (context, server);
366 	if (ret) {
367 	    char *errbuf;
368 	    const char *err_str;
369 
370 	    err_str = krb5_get_error_message(context, ret);
371 	    asprintf(&errbuf,
372 		     "Read req failed: %s", err_str);
373 	    krb5_free_error_message(context, err_str);
374 	    Data(ap, KRB_REJECT, errbuf, -1);
375 	    if (auth_debug_mode)
376 		printf("%s\r\n", errbuf);
377 	    free (errbuf);
378 	    return;
379 	}
380 
381 	{
382 	    char foo[2];
383 
384 	    foo[0] = ap->type;
385 	    foo[1] = ap->way;
386 
387 	    ret = krb5_verify_authenticator_checksum(context,
388 						     auth_context,
389 						     foo,
390 						     sizeof(foo));
391 
392 	    if (ret) {
393 		char *errbuf;
394 		const char *err_str;
395 
396 		err_str = krb5_get_error_message(context, ret);
397 		asprintf(&errbuf, "Bad checksum: %s", err_str);
398 		krb5_free_error_message(context, err_str);
399 		Data(ap, KRB_REJECT, errbuf, -1);
400 		if (auth_debug_mode)
401 		    printf ("%s\r\n", errbuf);
402 		free(errbuf);
403 		return;
404 	    }
405 	}
406 	ret = krb5_auth_con_getremotesubkey (context,
407 					     auth_context,
408 					     &key_block);
409 
410 	if (ret) {
411 	    Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
412 	    auth_finished(ap, AUTH_REJECT);
413 	    if (auth_debug_mode)
414 		print_krb5_error(context, ret, "Kerberos V5: "
415 		       "krb5_auth_con_getremotesubkey failed (%s)\r\n");
416 	    return;
417 	}
418 
419 	if (key_block == NULL) {
420 	    ret = krb5_auth_con_getkey(context,
421 				       auth_context,
422 				       &key_block);
423 	}
424 	if (ret) {
425 	    Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
426 	    auth_finished(ap, AUTH_REJECT);
427 	    if (auth_debug_mode)
428 		print_krb5_error(context, ret, "Kerberos V5: "
429 		       "krb5_auth_con_getkey failed (%s)\r\n");
430 	    return;
431 	}
432 	if (key_block == NULL) {
433 	    Data(ap, KRB_REJECT, "no subkey received", -1);
434 	    auth_finished(ap, AUTH_REJECT);
435 	    if (auth_debug_mode)
436 		printf("Kerberos V5: "
437 		       "krb5_auth_con_getremotesubkey returned NULL key\r\n");
438 	    return;
439 	}
440 
441 	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
442 	    ret = krb5_mk_rep(context, auth_context, &outbuf);
443 	    if (ret) {
444 		Data(ap, KRB_REJECT,
445 		     "krb5_mk_rep failed", -1);
446 		auth_finished(ap, AUTH_REJECT);
447 		if (auth_debug_mode)
448 		    print_krb5_error(context, ret, "Kerberos V5: "
449 			   "krb5_mk_rep failed (%s)\r\n");
450 		return;
451 	    }
452 	    Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
453 	}
454 	if (krb5_unparse_name(context, ticket->client, &name))
455 	    name = 0;
456 
457 	if(UserNameRequested && krb5_kuserok(context,
458 					     ticket->client,
459 					     UserNameRequested)) {
460 	    Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
461 	    if (auth_debug_mode) {
462 		printf("Kerberos5 identifies him as ``%s''\r\n",
463 		       name ? name : "");
464 	    }
465 
466 	    if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
467 	       key_block->keytype == ETYPE_DES_CBC_MD4 ||
468 	       key_block->keytype == ETYPE_DES_CBC_CRC) {
469 		Session_Key skey;
470 
471 		skey.type = SK_DES;
472 		skey.length = 8;
473 		skey.data = key_block->keyvalue.data;
474 		encrypt_session_key(&skey, 0);
475 	    }
476 
477 	} else {
478 	    char *msg;
479 
480 	    asprintf (&msg, "user `%s' is not authorized to "
481 		      "login as `%s'",
482 		      name ? name : "<unknown>",
483 		      UserNameRequested ? UserNameRequested : "<nobody>");
484 	    if (msg == NULL)
485 		Data(ap, KRB_REJECT, NULL, 0);
486 	    else {
487 		Data(ap, KRB_REJECT, (void *)msg, -1);
488 		free(msg);
489 	    }
490 	    auth_finished (ap, AUTH_REJECT);
491 	    krb5_free_keyblock_contents(context, key_block);
492 	    break;
493 	}
494 	auth_finished(ap, AUTH_USER);
495 	krb5_free_keyblock_contents(context, key_block);
496 
497 	break;
498     case KRB_FORWARD: {
499 	struct passwd *pwd;
500 	char ccname[1024];	/* XXX */
501 	krb5_data inbuf;
502 	krb5_ccache ccache;
503 	inbuf.data = (char *)data;
504 	inbuf.length = cnt;
505 
506 	pwd = getpwnam (UserNameRequested);
507 	if (pwd == NULL)
508 	    break;
509 
510 	snprintf (ccname, sizeof(ccname),
511 		  "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
512 
513 	ret = krb5_cc_resolve (context, ccname, &ccache);
514 	if (ret) {
515 	    if (auth_debug_mode)
516 		print_krb5_error(context, ret, "Kerberos V5: could not get ccache: %s\r\n");
517 	    break;
518 	}
519 
520 	ret = krb5_cc_initialize (context,
521 				  ccache,
522 				  ticket->client);
523 	if (ret) {
524 	    if (auth_debug_mode)
525 		print_krb5_error(context, ret, "Kerberos V5: could not init ccache: %s\r\n");
526 	    break;
527 	}
528 
529 #if defined(DCE)
530 	esetenv("KRB5CCNAME", ccname, 1);
531 #endif
532 	ret = krb5_rd_cred2 (context,
533 			     auth_context,
534 			     ccache,
535 			     &inbuf);
536 	if(ret) {
537 	    char *errbuf;
538 	    const char *err_str;
539 
540 	    err_str = krb5_get_error_message(context, ret);
541 	    asprintf (&errbuf,
542 		      "Read forwarded creds failed: %s", err_str);
543 	    krb5_free_error_message(context, err_str);
544 	    if(errbuf == NULL)
545 		Data(ap, KRB_FORWARD_REJECT, NULL, 0);
546 	    else
547 		Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
548 	    if (auth_debug_mode)
549 		printf("Could not read forwarded credentials: %s\r\n",
550 		       errbuf);
551 	    free (errbuf);
552 	} else {
553 	    Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
554 #if defined(DCE)
555 	    dfsfwd = 1;
556 #endif
557 	}
558 	chown (ccname + 5, pwd->pw_uid, -1);
559 	if (auth_debug_mode)
560 	    printf("Forwarded credentials obtained\r\n");
561 	break;
562     }
563     default:
564 	if (auth_debug_mode)
565 	    printf("Unknown Kerberos option %d\r\n", data[-1]);
566 	Data(ap, KRB_REJECT, 0, 0);
567 	break;
568     }
569 }
570 
571 void
572 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
573 {
574     static int mutual_complete = 0;
575 
576     if (cnt-- < 1)
577 	return;
578     switch (*data++) {
579     case KRB_REJECT:
580 	if (cnt > 0) {
581 	    printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
582 		   cnt, data);
583 	} else
584 	    printf("[ Kerberos V5 refuses authentication ]\r\n");
585 	auth_send_retry();
586 	return;
587     case KRB_ACCEPT: {
588 	krb5_error_code ret;
589 	Session_Key skey;
590 	krb5_keyblock *keyblock;
591 
592 	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
593 	    !mutual_complete) {
594 	    printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
595 	    auth_send_retry();
596 	    return;
597 	}
598 	if (cnt)
599 	    printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
600 	else
601 	    printf("[ Kerberos V5 accepts you ]\r\n");
602 
603 	ret = krb5_auth_con_getlocalsubkey (context,
604 					    auth_context,
605 					    &keyblock);
606 	if (ret)
607 	    ret = krb5_auth_con_getkey (context,
608 					auth_context,
609 					&keyblock);
610 	if(ret) {
611 	    print_krb5_error(context, ret, "[ krb5_auth_con_getkey: %s ]\r\n");
612 	    auth_send_retry();
613 	    return;
614 	}
615 
616 	skey.type = SK_DES;
617 	skey.length = 8;
618 	skey.data = keyblock->keyvalue.data;
619 	encrypt_session_key(&skey, 0);
620 	krb5_free_keyblock_contents (context, keyblock);
621 	auth_finished(ap, AUTH_USER);
622 	if (forward_flags & OPTS_FORWARD_CREDS)
623 	    kerberos5_forward(ap);
624 	break;
625     }
626     case KRB_RESPONSE:
627 	if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
628 	    /* the rest of the reply should contain a krb_ap_rep */
629 	  krb5_ap_rep_enc_part *reply;
630 	  krb5_data inbuf;
631 	  krb5_error_code ret;
632 
633 	  inbuf.length = cnt;
634 	  inbuf.data = (char *)data;
635 
636 	  ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
637 	  if (ret) {
638 	      print_krb5_error(context, ret, "[ Mutual authentication failed: %s ]\r\n");
639 	      auth_send_retry();
640 	      return;
641 	  }
642 	  krb5_free_ap_rep_enc_part(context, reply);
643 	  mutual_complete = 1;
644 	}
645 	return;
646     case KRB_FORWARD_ACCEPT:
647 	printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
648 	return;
649     case KRB_FORWARD_REJECT:
650 	printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
651 	       cnt, data);
652 	return;
653     default:
654 	if (auth_debug_mode)
655 	    printf("Unknown Kerberos option %d\r\n", data[-1]);
656 	return;
657     }
658 }
659 
660 int
661 kerberos5_status(Authenticator *ap __unused, char *name, int level)
662 {
663     if (level < AUTH_USER)
664 	return(level);
665 
666     if (UserNameRequested &&
667 	krb5_kuserok(context,
668 		     ticket->client,
669 		     UserNameRequested))
670 	{
671 	    strcpy(name, UserNameRequested);
672 	    return(AUTH_VALID);
673 	} else
674 	    return(AUTH_USER);
675 }
676 
677 #define	BUMP(buf, len)		while (*(buf)) {++(buf), --(len);}
678 #define	ADDC(buf, len, c)	if ((len) > 0) {*(buf)++ = (c); --(len);}
679 
680 void
681 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
682 {
683     int i;
684 
685     buf[buflen-1] = '\0';		/* make sure its NULL terminated */
686     buflen -= 1;
687 
688     switch(data[3]) {
689     case KRB_REJECT:		/* Rejected (reason might follow) */
690 	strlcpy((char *)buf, " REJECT ", buflen);
691 	goto common;
692 
693     case KRB_ACCEPT:		/* Accepted (name might follow) */
694 	strlcpy((char *)buf, " ACCEPT ", buflen);
695     common:
696 	BUMP(buf, buflen);
697 	if (cnt <= 4)
698 	    break;
699 	ADDC(buf, buflen, '"');
700 	for (i = 4; i < cnt; i++)
701 	    ADDC(buf, buflen, data[i]);
702 	ADDC(buf, buflen, '"');
703 	ADDC(buf, buflen, '\0');
704 	break;
705 
706 
707     case KRB_AUTH:			/* Authentication data follows */
708 	strlcpy((char *)buf, " AUTH", buflen);
709 	goto common2;
710 
711     case KRB_RESPONSE:
712 	strlcpy((char *)buf, " RESPONSE", buflen);
713 	goto common2;
714 
715     case KRB_FORWARD:		/* Forwarded credentials follow */
716 	strlcpy((char *)buf, " FORWARD", buflen);
717 	goto common2;
718 
719     case KRB_FORWARD_ACCEPT:	/* Forwarded credentials accepted */
720 	strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
721 	goto common2;
722 
723     case KRB_FORWARD_REJECT:	/* Forwarded credentials rejected */
724 	/* (reason might follow) */
725 	strlcpy((char *)buf, " FORWARD_REJECT", buflen);
726 	goto common2;
727 
728     default:
729 	snprintf(buf, buflen, " %d (unknown)", data[3]);
730     common2:
731 	BUMP(buf, buflen);
732 	for (i = 4; i < cnt; i++) {
733 	    snprintf(buf, buflen, " %d", data[i]);
734 	    BUMP(buf, buflen);
735 	}
736 	break;
737     }
738 }
739 
740 void
741 kerberos5_forward(Authenticator *ap)
742 {
743     krb5_error_code ret;
744     krb5_ccache     ccache;
745     krb5_creds      creds;
746     krb5_kdc_flags  flags;
747     krb5_data       out_data;
748     krb5_principal  principal;
749 
750     ret = krb5_cc_default (context, &ccache);
751     if (ret) {
752 	if (auth_debug_mode)
753 	    print_krb5_error(context, ret, "KerberosV5: could not get default ccache: %s\r\n");
754 	return;
755     }
756 
757     ret = krb5_cc_get_principal (context, ccache, &principal);
758     if (ret) {
759 	if (auth_debug_mode)
760 	    print_krb5_error(context, ret, "KerberosV5: could not get principal: %s\r\n");
761 	return;
762     }
763 
764     memset (&creds, 0, sizeof(creds));
765 
766     creds.client = principal;
767 
768     ret = krb5_build_principal (context,
769 				&creds.server,
770 				strlen(principal->realm),
771 				principal->realm,
772 				"krbtgt",
773 				principal->realm,
774 				NULL);
775 
776     if (ret) {
777 	if (auth_debug_mode)
778 	    print_krb5_error(context, ret, "KerberosV5: could not get principal: %s\r\n");
779 	return;
780     }
781 
782     creds.times.endtime = 0;
783 
784     flags.i = 0;
785     flags.b.forwarded = 1;
786     if (forward_flags & OPTS_FORWARDABLE_CREDS)
787 	flags.b.forwardable = 1;
788 
789     ret = krb5_get_forwarded_creds (context,
790 				    auth_context,
791 				    ccache,
792 				    flags.i,
793 				    RemoteHostName,
794 				    &creds,
795 				    &out_data);
796     if (ret) {
797 	if (auth_debug_mode)
798 	    print_krb5_error(context, ret, "Kerberos V5: error getting forwarded creds: %s\r\n");
799 	return;
800     }
801 
802     if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
803 	if (auth_debug_mode)
804 	    printf("Not enough room for authentication data\r\n");
805     } else {
806 	if (auth_debug_mode)
807 	    printf("Forwarded local Kerberos V5 credentials to server\r\n");
808     }
809 }
810 
811 #if defined(DCE)
812 /* if this was a K5 authentication try and join a PAG for the user. */
813 void
814 kerberos5_dfspag(void)
815 {
816     if (dfsk5ok) {
817 	dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
818 			      UserNameRequested);
819     }
820 }
821 #endif
822 
823 #endif /* KRB5 */
824