kerberos5.c revision 1.19 1 /* $NetBSD: kerberos5.c,v 1.19 2012/01/09 15:25:33 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Copyright (C) 1990 by the Massachusetts Institute of Technology
34 *
35 * Export of this software from the United States of America may
36 * require a specific license from the United States Government.
37 * It is the responsibility of any person or organization contemplating
38 * export to obtain such a license before exporting.
39 *
40 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
41 * distribute this software and its documentation for any purpose and
42 * without fee is hereby granted, provided that the above copyright
43 * notice appear in all copies and that both that copyright notice and
44 * this permission notice appear in supporting documentation, and that
45 * the name of M.I.T. not be used in advertising or publicity pertaining
46 * to distribution of the software without specific, written prior
47 * permission. M.I.T. makes no representations about the suitability of
48 * this software for any purpose. It is provided "as is" without express
49 * or implied warranty.
50 */
51
52 #ifdef KRB5
53 #include <arpa/telnet.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <netdb.h>
59 #include <ctype.h>
60 #include <pwd.h>
61 #define Authenticator k5_Authenticator
62 #include <krb5.h>
63 #undef Authenticator
64 /* #include <roken.h> */
65
66 #include "encrypt.h"
67 #include "auth.h"
68 #include "misc.h"
69
70 extern int net;
71
72 int forward_flags; /* Flags get set in telnet/main.c on -f and -F */
73 int got_forwarded_creds;/* Tell telnetd to pass -F or -f to login. */
74
75 int require_hwpreauth;
76
77 const char *get_krb5_err_text(krb5_context, krb5_error_code);
78 void kerberos5_forward(Authenticator *);
79
80 static unsigned char str_data[1024] = {IAC, SB, TELOPT_AUTHENTICATION, 0,
81 AUTHTYPE_KERBEROS_V5,};
82
83 #define KRB_AUTH 0 /* Authentication data follows */
84 #define KRB_REJECT 1 /* Rejected (reason might follow) */
85 #define KRB_ACCEPT 2 /* Accepted */
86 #define KRB_RESPONSE 3 /* Response for mutual auth. */
87
88 #define KRB_FORWARD 4 /* Forwarded credentials follow */
89 #define KRB_FORWARD_ACCEPT 5 /* Forwarded credentials accepted */
90 #define KRB_FORWARD_REJECT 6 /* Forwarded credentials rejected */
91
92 static krb5_data auth;
93 static krb5_ticket *ticket;
94
95 krb5_context telnet_context;
96 static krb5_auth_context auth_context;
97
98 static int
99 Data(Authenticator *ap, int type, const void *d, int c)
100 {
101 unsigned char *p = str_data + 4;
102 const unsigned char *cd = (const unsigned char *) d;
103
104 if (c == -1)
105 c = strlen(cd);
106
107 if (auth_debug_mode) {
108 printf("%s:%d: [%d] (%d)",
109 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
110 str_data[3],
111 type, c);
112 printd(d, c);
113 printf("\r\n");
114 }
115 *p++ = ap->type;
116 *p++ = ap->way;
117 *p++ = type;
118 while (c-- > 0) {
119 if ((*p++ = *cd++) == IAC)
120 *p++ = IAC;
121 }
122 *p++ = IAC;
123 *p++ = SE;
124 if (str_data[3] == TELQUAL_IS)
125 printsub('>', &str_data[2], p - &str_data[2]);
126 return (telnet_net_write(str_data, p - str_data));
127 }
128
129 const char *
130 get_krb5_err_text(krb5_context ctx, krb5_error_code ret)
131 {
132 static const char *str = NULL;
133
134 if (str)
135 krb5_free_error_message(ctx, str);
136
137 str = krb5_get_error_message(ctx, ret);
138
139 if (str != NULL)
140 return str;
141
142 return "unknown";
143 }
144
145 int
146 kerberos5_init(Authenticator *ap, int server)
147 {
148 krb5_error_code ret;
149
150 if (telnet_context == 0) {
151 ret = krb5_init_context(&telnet_context);
152 if (ret)
153 return 0;
154 }
155
156 if (server) {
157 krb5_keytab kt;
158 krb5_kt_cursor cursor;
159
160 ret = krb5_kt_default(telnet_context, &kt);
161 if (ret)
162 return 0;
163
164 ret = krb5_kt_start_seq_get(telnet_context, kt, &cursor);
165 if (ret) {
166 krb5_kt_close(telnet_context, kt);
167 return 0;
168 }
169 krb5_kt_end_seq_get(telnet_context, kt, &cursor);
170 krb5_kt_close(telnet_context, kt);
171
172 str_data[3] = TELQUAL_REPLY;
173 } else
174 str_data[3] = TELQUAL_IS;
175 return (1);
176 }
177
178 int
179 kerberos5_send(Authenticator *ap)
180 {
181 krb5_error_code ret;
182 krb5_ccache ccache;
183 int ap_opts;
184 krb5_data cksum_data;
185 char foo[2];
186
187 printf("[ Trying KERBEROS5 ... ]\r\n");
188
189 if (!UserNameRequested) {
190 if (auth_debug_mode) {
191 printf("Kerberos V5: no user name supplied\r\n");
192 }
193 return (0);
194 }
195 ret = krb5_cc_default(telnet_context, &ccache);
196 if (ret) {
197 if (auth_debug_mode) {
198 printf(
199 "Kerberos V5: could not get default ccache: %s\r\n",
200 get_krb5_err_text(telnet_context, ret));
201 }
202 return (0);
203 }
204 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
205 ap_opts = AP_OPTS_MUTUAL_REQUIRED;
206 else
207 ap_opts = 0;
208
209 ap_opts |= AP_OPTS_USE_SUBKEY;
210
211 ret = krb5_auth_con_init(telnet_context, &auth_context);
212 if (ret) {
213 if (auth_debug_mode) {
214 printf(
215 "Kerberos V5: krb5_auth_con_init failed: %s\r\n",
216 get_krb5_err_text(telnet_context, ret));
217 }
218 return (0);
219 }
220 ret = krb5_auth_con_setaddrs_from_fd(telnet_context,
221 auth_context, &net);
222 if (ret) {
223 if (auth_debug_mode) {
224 printf("Kerberos V5: "
225 "krb5_auth_con_setaddrs_from_fd failed: %s\r\n",
226 get_krb5_err_text(telnet_context, ret));
227 }
228 return (0);
229 }
230 krb5_auth_con_setkeytype(telnet_context, auth_context, KEYTYPE_DES);
231
232 foo[0] = ap->type;
233 foo[1] = ap->way;
234
235 cksum_data.length = sizeof(foo);
236 cksum_data.data = foo;
237 ret = krb5_mk_req(telnet_context, &auth_context, ap_opts, "host",
238 RemoteHostName, &cksum_data, ccache, &auth);
239 if (ret) {
240 if (1 || auth_debug_mode) {
241 printf("Kerberos V5: mk_req failed (%s)\r\n",
242 get_krb5_err_text(telnet_context, ret));
243 }
244 return (0);
245 }
246
247 if (!auth_sendname((unsigned char *) UserNameRequested,
248 strlen(UserNameRequested))) {
249 if (auth_debug_mode)
250 printf("Not enough room for user name\r\n");
251 return (0);
252 }
253 if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
254 if (auth_debug_mode)
255 printf("Not enough room for authentication data\r\n");
256 return (0);
257 }
258 if (auth_debug_mode) {
259 printf("Sent Kerberos V5 credentials to server\r\n");
260 }
261 return (1);
262 }
263
264 void
265 kerberos5_is(Authenticator * ap, unsigned char *data, int cnt)
266 {
267 krb5_error_code ret;
268 krb5_data outbuf;
269 krb5_keyblock *key_block;
270 char *name;
271 krb5_principal server;
272 int zero = 0;
273
274 if (cnt-- < 1)
275 return;
276 switch (*data++) {
277 case KRB_AUTH:
278 auth.data = (char *) data;
279 auth.length = cnt;
280
281 auth_context = NULL;
282
283 ret = krb5_auth_con_init(telnet_context, &auth_context);
284 if (ret) {
285 Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
286 auth_finished(ap, AUTH_REJECT);
287 if (auth_debug_mode)
288 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
289 get_krb5_err_text(telnet_context, ret));
290 return;
291 }
292 ret = krb5_auth_con_setaddrs_from_fd(telnet_context,
293 auth_context, &zero);
294 if (ret) {
295 Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
296 auth_finished(ap, AUTH_REJECT);
297 if (auth_debug_mode)
298 printf("Kerberos V5: "
299 "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
300 get_krb5_err_text(telnet_context, ret));
301 return;
302 }
303 ret = krb5_sock_to_principal(telnet_context, 0, "host",
304 KRB5_NT_SRV_HST, &server);
305 if (ret) {
306 Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
307 auth_finished(ap, AUTH_REJECT);
308 if (auth_debug_mode)
309 printf("Kerberos V5: "
310 "krb5_sock_to_principal failed (%s)\r\n",
311 get_krb5_err_text(telnet_context, ret));
312 return;
313 }
314 ret = krb5_rd_req(telnet_context, &auth_context, &auth,
315 server, NULL, NULL, &ticket);
316 krb5_free_principal(telnet_context, server);
317
318 if (ret) {
319 char *errbuf;
320
321 asprintf(&errbuf,
322 "Read req failed: %s",
323 get_krb5_err_text(telnet_context, ret));
324 Data(ap, KRB_REJECT, errbuf, -1);
325 if (auth_debug_mode)
326 printf("%s\r\n", errbuf);
327 free(errbuf);
328 return;
329 } {
330 char foo[2];
331
332 foo[0] = ap->type;
333 foo[1] = ap->way;
334
335 ret = krb5_verify_authenticator_checksum(telnet_context,
336 auth_context, foo, sizeof(foo));
337
338 if (ret) {
339 char *errbuf;
340 asprintf(&errbuf, "Bad checksum: %s",
341 get_krb5_err_text(telnet_context, ret));
342 Data(ap, KRB_REJECT, errbuf, -1);
343 if (auth_debug_mode)
344 printf("%s\r\n", errbuf);
345 free(errbuf);
346 return;
347 }
348 }
349 ret = krb5_auth_con_getremotesubkey(telnet_context,
350 auth_context, &key_block);
351
352 if (ret) {
353 Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
354 auth_finished(ap, AUTH_REJECT);
355 if (auth_debug_mode)
356 printf("Kerberos V5: "
357 "krb5_auth_con_getremotesubkey failed (%s)\r\n",
358 get_krb5_err_text(telnet_context, ret));
359 return;
360 }
361 if (key_block == NULL) {
362 ret = krb5_auth_con_getkey(telnet_context,
363 auth_context,
364 &key_block);
365 }
366 if (ret) {
367 Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
368 auth_finished(ap, AUTH_REJECT);
369 if (auth_debug_mode)
370 printf("Kerberos V5: "
371 "krb5_auth_con_getkey failed (%s)\r\n",
372 get_krb5_err_text(telnet_context, ret));
373 return;
374 }
375 if (key_block == NULL) {
376 Data(ap, KRB_REJECT, "no subkey received", -1);
377 auth_finished(ap, AUTH_REJECT);
378 if (auth_debug_mode)
379 printf("Kerberos V5: "
380 "krb5_auth_con_getremotesubkey returned NULL key\r\n");
381 return;
382 }
383 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
384 ret = krb5_mk_rep(telnet_context,
385 auth_context, &outbuf);
386 if (ret) {
387 Data(ap, KRB_REJECT,
388 "krb5_mk_rep failed", -1);
389 auth_finished(ap, AUTH_REJECT);
390 if (auth_debug_mode)
391 printf("Kerberos V5: "
392 "krb5_mk_rep failed (%s)\r\n",
393 get_krb5_err_text(telnet_context,
394 ret));
395 krb5_free_keyblock(telnet_context, key_block);
396 return;
397 }
398 Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
399 }
400 if (krb5_unparse_name(telnet_context, ticket->client, &name))
401 name = 0;
402
403 if (UserNameRequested && krb5_kuserok(telnet_context,
404 ticket->client, UserNameRequested)) {
405 Data(ap, KRB_ACCEPT, name ? name : "", name ? -1 : 0);
406 if (auth_debug_mode) {
407 printf("Kerberos5 identifies him as ``%s''\r\n",
408 name ? name : "");
409 }
410 if (key_block->keytype == ETYPE_DES_CBC_MD5 ||
411 key_block->keytype == ETYPE_DES_CBC_MD4 ||
412 key_block->keytype == ETYPE_DES_CBC_CRC) {
413 Session_Key skey;
414
415 skey.type = SK_DES;
416 skey.length = 8;
417 skey.data = key_block->keyvalue.data;
418 encrypt_session_key(&skey, 0);
419 }
420 } else {
421 char *msg;
422
423 asprintf(&msg, "user `%s' is not authorized to "
424 "login as `%s'",
425 name ? name : "<unknown>",
426 UserNameRequested ? UserNameRequested : "<nobody>");
427 if (msg == NULL)
428 Data(ap, KRB_REJECT, NULL, 0);
429 else {
430 Data(ap, KRB_REJECT, (void *) msg, -1);
431 free(msg);
432 }
433 auth_finished(ap, AUTH_REJECT);
434 krb5_free_keyblock(telnet_context, key_block);
435 break;
436 }
437 auth_finished(ap, AUTH_USER);
438 krb5_free_keyblock(telnet_context, key_block);
439 break;
440 case KRB_FORWARD:{
441 struct passwd pws, *pwd;
442 char pwbuf[1024];
443 char ccname[1024]; /* XXX */
444 krb5_data inbuf;
445 krb5_ccache ccache;
446 inbuf.data = (char *) data;
447 inbuf.length = cnt;
448
449 if (getpwnam_r(UserNameRequested, &pws, pwbuf,
450 sizeof(pwbuf), &pwd) != 0 || pwd == NULL)
451 break;
452
453 snprintf(ccname, sizeof(ccname),
454 "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
455
456 ret = krb5_cc_resolve(telnet_context, ccname, &ccache);
457 if (ret) {
458 if (auth_debug_mode)
459 printf("Kerberos V5: could not get ccache: %s\r\n",
460 get_krb5_err_text(telnet_context,
461 ret));
462 break;
463 }
464 ret = krb5_cc_initialize(telnet_context, ccache,
465 ticket->client);
466 if (ret) {
467 if (auth_debug_mode)
468 printf("Kerberos V5: could not init ccache: %s\r\n",
469 get_krb5_err_text(telnet_context,
470 ret));
471 break;
472 }
473 ret = krb5_rd_cred2(telnet_context, auth_context,
474 ccache, &inbuf);
475 if (ret) {
476 char *errbuf;
477
478 asprintf(&errbuf,
479 "Read forwarded creds failed: %s",
480 get_krb5_err_text(telnet_context, ret));
481 if (errbuf == NULL)
482 Data(ap, KRB_FORWARD_REJECT, NULL, 0);
483 else
484 Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
485 if (auth_debug_mode)
486 printf("Could not read forwarded credentials: %s\r\n",
487 errbuf);
488 free(errbuf);
489 } else
490 Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
491 chown(ccname + 5, pwd->pw_uid, -1);
492 if (auth_debug_mode)
493 printf("Forwarded credentials obtained\r\n");
494 break;
495 }
496 default:
497 if (auth_debug_mode)
498 printf("Unknown Kerberos option %d\r\n", data[-1]);
499 Data(ap, KRB_REJECT, 0, 0);
500 break;
501 }
502 }
503
504 void
505 kerberos5_reply(Authenticator * ap, unsigned char *data, int cnt)
506 {
507 static int mutual_complete = 0;
508
509 if (cnt-- < 1)
510 return;
511 switch (*data++) {
512 case KRB_REJECT:
513 if (cnt > 0) {
514 printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
515 cnt, data);
516 } else
517 printf("[ Kerberos V5 refuses authentication ]\r\n");
518 auth_send_retry();
519 return;
520 case KRB_ACCEPT:{
521 krb5_error_code ret;
522 Session_Key skey;
523 krb5_keyblock *keyblock;
524
525 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
526 !mutual_complete) {
527 printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
528 auth_send_retry();
529 return;
530 }
531 if (cnt)
532 printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
533 else
534 printf("[ Kerberos V5 accepts you ]\r\n");
535
536 ret = krb5_auth_con_getlocalsubkey(telnet_context,
537 auth_context, &keyblock);
538 if (ret)
539 ret = krb5_auth_con_getkey(telnet_context,
540 auth_context, &keyblock);
541 if (ret) {
542 printf("[ krb5_auth_con_getkey: %s ]\r\n",
543 get_krb5_err_text(telnet_context, ret));
544 auth_send_retry();
545 return;
546 }
547 skey.type = SK_DES;
548 skey.length = 8;
549 skey.data = keyblock->keyvalue.data;
550 encrypt_session_key(&skey, 0);
551 krb5_free_keyblock(telnet_context, keyblock);
552 auth_finished(ap, AUTH_USER);
553 if (forward_flags & OPTS_FORWARD_CREDS)
554 kerberos5_forward(ap);
555 break;
556 }
557 case KRB_RESPONSE:
558 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
559 /* the rest of the reply should contain a krb_ap_rep */
560 krb5_ap_rep_enc_part *reply;
561 krb5_data inbuf;
562 krb5_error_code ret;
563
564 inbuf.length = cnt;
565 inbuf.data = (char *) data;
566
567 ret = krb5_rd_rep(telnet_context,
568 auth_context, &inbuf, &reply);
569 if (ret) {
570 printf("[ Mutual authentication failed: %s ]\r\n",
571 get_krb5_err_text(telnet_context, ret));
572 auth_send_retry();
573 return;
574 }
575 krb5_free_ap_rep_enc_part(telnet_context, reply);
576 mutual_complete = 1;
577 }
578 return;
579 case KRB_FORWARD_ACCEPT:
580 printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
581 return;
582 case KRB_FORWARD_REJECT:
583 printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
584 cnt, data);
585 return;
586 default:
587 if (auth_debug_mode)
588 printf("Unknown Kerberos option %d\r\n", data[-1]);
589 return;
590 }
591 }
592
593 int
594 kerberos5_status(Authenticator *ap, char *name, size_t l, int level)
595 {
596 if (level < AUTH_USER)
597 return (level);
598
599 if (UserNameRequested &&
600 krb5_kuserok(telnet_context, ticket->client, UserNameRequested)) {
601 strlcpy(name, UserNameRequested, l);
602 return (AUTH_VALID);
603 } else
604 return (AUTH_USER);
605 }
606 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
607 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
608
609 void
610 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
611 {
612 int i;
613
614 buf[buflen - 1] = '\0'; /* make sure its NULL terminated */
615 buflen -= 1;
616
617 switch (data[3]) {
618 case KRB_REJECT: /* Rejected (reason might follow) */
619 strlcpy((char *) buf, " REJECT ", buflen);
620 goto common;
621
622 case KRB_ACCEPT: /* Accepted (name might follow) */
623 strlcpy((char *) buf, " ACCEPT ", buflen);
624 common:
625 BUMP(buf, buflen);
626 if (cnt <= 4)
627 break;
628 ADDC(buf, buflen, '"');
629 for (i = 4; i < cnt; i++)
630 ADDC(buf, buflen, data[i]);
631 ADDC(buf, buflen, '"');
632 ADDC(buf, buflen, '\0');
633 break;
634
635
636 case KRB_AUTH: /* Authentication data follows */
637 strlcpy((char *) buf, " AUTH", buflen);
638 goto common2;
639
640 case KRB_RESPONSE:
641 strlcpy((char *) buf, " RESPONSE", buflen);
642 goto common2;
643
644 case KRB_FORWARD: /* Forwarded credentials follow */
645 strlcpy((char *) buf, " FORWARD", buflen);
646 goto common2;
647
648 case KRB_FORWARD_ACCEPT: /* Forwarded credentials accepted */
649 strlcpy((char *) buf, " FORWARD_ACCEPT", buflen);
650 goto common2;
651
652 case KRB_FORWARD_REJECT: /* Forwarded credentials rejected */
653 /* (reason might follow) */
654 strlcpy((char *) buf, " FORWARD_REJECT", buflen);
655 goto common2;
656
657 default:
658 snprintf(buf, buflen, " %d (unknown)", data[3]);
659 common2:
660 BUMP(buf, buflen);
661 for (i = 4; i < cnt; i++) {
662 snprintf(buf, buflen, " %d", data[i]);
663 BUMP(buf, buflen);
664 }
665 break;
666 }
667 }
668
669 void
670 kerberos5_forward(Authenticator * ap)
671 {
672 krb5_error_code ret;
673 krb5_ccache ccache;
674 krb5_creds creds;
675 krb5_kdc_flags flags;
676 krb5_data out_data;
677 krb5_principal principal;
678
679 ret = krb5_cc_default(telnet_context, &ccache);
680 if (ret) {
681 if (auth_debug_mode)
682 printf("KerberosV5: could not get default ccache: %s\r\n",
683 get_krb5_err_text(telnet_context, ret));
684 return;
685 }
686 ret = krb5_cc_get_principal(telnet_context, ccache, &principal);
687 if (ret) {
688 if (auth_debug_mode)
689 printf("KerberosV5: could not get principal: %s\r\n",
690 get_krb5_err_text(telnet_context, ret));
691 return;
692 }
693 memset(&creds, 0, sizeof(creds));
694
695 creds.client = principal;
696
697 ret = krb5_build_principal(telnet_context, &creds.server,
698 strlen(principal->realm), principal->realm, "krbtgt",
699 principal->realm, NULL);
700
701 if (ret) {
702 if (auth_debug_mode)
703 printf("KerberosV5: could not get principal: %s\r\n",
704 get_krb5_err_text(telnet_context, ret));
705 return;
706 }
707 creds.times.endtime = 0;
708
709 flags.i = 0;
710 flags.b.forwarded = 1;
711 if (forward_flags & OPTS_FORWARDABLE_CREDS)
712 flags.b.forwardable = 1;
713
714 ret = krb5_get_forwarded_creds(telnet_context, auth_context,
715 ccache, flags.i, RemoteHostName, &creds, &out_data);
716 if (ret) {
717 if (auth_debug_mode)
718 printf("Kerberos V5: error getting forwarded creds: %s\r\n",
719 get_krb5_err_text(telnet_context, ret));
720 return;
721 }
722 if (!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
723 if (auth_debug_mode)
724 printf("Not enough room for authentication data\r\n");
725 } else {
726 if (auth_debug_mode)
727 printf("Forwarded local Kerberos V5 credentials to server\r\n");
728 }
729 }
730 #endif /* KRB5 */
731