2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
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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
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29 * $FreeBSD: src/crypto/telnet/libtelnet/kerberos5.c,v 1.1.1.1.8.2 2003/04/24 19:13:59 nectar Exp $
33 * Copyright (C) 1990 by the Massachusetts Institute of Technology
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.
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.
54 #include <arpa/telnet.h>
62 #define Authenticator k5_Authenticator
70 int forward_flags = 0; /* Flags get set in telnet/main.c on -f and -F */
72 /* These values need to be the same as those defined in telnet/main.c. */
73 /* Either define them in both places, or put in some common header file. */
74 #define OPTS_FORWARD_CREDS 0x00000002
75 #define OPTS_FORWARDABLE_CREDS 0x00000001
77 void kerberos5_forward (Authenticator *);
79 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
80 AUTHTYPE_KERBEROS_V5, };
82 #define KRB_AUTH 0 /* Authentication data follows */
83 #define KRB_REJECT 1 /* Rejected (reason might follow) */
84 #define KRB_ACCEPT 2 /* Accepted */
85 #define KRB_RESPONSE 3 /* Response for mutual auth. */
87 #define KRB_FORWARD 4 /* Forwarded credentials follow */
88 #define KRB_FORWARD_ACCEPT 5 /* Forwarded credentials accepted */
89 #define KRB_FORWARD_REJECT 6 /* Forwarded credentials rejected */
91 static krb5_data auth;
92 static krb5_ticket *ticket;
94 static krb5_context context;
95 static krb5_auth_context auth_context;
98 Data(Authenticator *ap, int type, const char *d, int c)
100 unsigned char *p = str_data + 4;
101 const unsigned char *cd = d;
106 if (auth_debug_mode) {
107 printf("%s:%d: [%d] (%d)",
108 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
118 if ((*p++ = *cd++) == IAC)
123 if (str_data[3] == TELQUAL_IS)
124 printsub('>', &str_data[2], p - &str_data[2]);
125 return(net_write(str_data, p - str_data));
129 kerberos5_init(Authenticator *ap __unused, int server)
133 ret = krb5_init_context(&context);
138 krb5_kt_cursor cursor;
140 ret = krb5_kt_default(context, &kt);
144 ret = krb5_kt_start_seq_get (context, kt, &cursor);
146 krb5_kt_close (context, kt);
149 krb5_kt_end_seq_get (context, kt, &cursor);
150 krb5_kt_close (context, kt);
152 str_data[3] = TELQUAL_REPLY;
154 str_data[3] = TELQUAL_IS;
161 kerberos5_send(const char *name, Authenticator *ap)
166 krb5_data cksum_data;
169 if (!UserNameRequested) {
170 if (auth_debug_mode) {
171 printf("Kerberos V5: no user name supplied\r\n");
176 ret = krb5_cc_default(context, &ccache);
178 if (auth_debug_mode) {
179 printf("Kerberos V5: could not get default ccache: %s\r\n",
180 krb5_get_err_text (context, ret));
185 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
186 ap_opts = AP_OPTS_MUTUAL_REQUIRED;
189 ap_opts |= AP_OPTS_USE_SUBKEY;
191 ret = krb5_auth_con_init (context, &auth_context);
193 if (auth_debug_mode) {
194 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
195 krb5_get_err_text(context, ret));
200 ret = krb5_auth_con_setaddrs_from_fd (context,
204 if (auth_debug_mode) {
205 printf ("Kerberos V5:"
206 " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
207 krb5_get_err_text(context, ret));
212 krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
217 cksum_data.length = sizeof(foo);
218 cksum_data.data = foo;
222 krb5_principal service;
226 ret = krb5_sname_to_principal (context,
232 if (auth_debug_mode) {
233 printf ("Kerberos V5:"
234 " krb5_sname_to_principal(%s) failed (%s)\r\n",
235 RemoteHostName, krb5_get_err_text(context, ret));
239 ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
241 if (auth_debug_mode) {
242 printf ("Kerberos V5:"
243 " krb5_unparse_name_fixed failed (%s)\r\n",
244 krb5_get_err_text(context, ret));
248 printf("[ Trying %s (%s)... ]\r\n", name, sname);
249 ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
251 &cksum_data, ccache, &auth);
252 krb5_free_principal (context, service);
256 if (1 || auth_debug_mode) {
257 printf("Kerberos V5: mk_req failed (%s)\r\n",
258 krb5_get_err_text(context, ret));
263 if (!auth_sendname((unsigned char *)UserNameRequested,
264 strlen(UserNameRequested))) {
266 printf("Not enough room for user name\r\n");
269 if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
271 printf("Not enough room for authentication data\r\n");
274 if (auth_debug_mode) {
275 printf("Sent Kerberos V5 credentials to server\r\n");
281 kerberos5_send_mutual(Authenticator *ap)
283 return kerberos5_send("mutual KERBEROS5", ap);
287 kerberos5_send_oneway(Authenticator *ap)
289 return kerberos5_send("KERBEROS5", ap);
293 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
297 krb5_keyblock *key_block;
299 krb5_principal server;
306 auth.data = (char *)data;
311 ret = krb5_auth_con_init (context, &auth_context);
313 Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
314 auth_finished(ap, AUTH_REJECT);
316 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
317 krb5_get_err_text(context, ret));
321 ret = krb5_auth_con_setaddrs_from_fd (context,
325 Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
326 auth_finished(ap, AUTH_REJECT);
328 printf("Kerberos V5: "
329 "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
330 krb5_get_err_text(context, ret));
334 ret = krb5_sock_to_principal (context,
340 Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
341 auth_finished(ap, AUTH_REJECT);
343 printf("Kerberos V5: "
344 "krb5_sock_to_principal failed (%s)\r\n",
345 krb5_get_err_text(context, ret));
349 ret = krb5_rd_req(context,
357 krb5_free_principal (context, server);
362 "Read req failed: %s",
363 krb5_get_err_text(context, ret));
364 Data(ap, KRB_REJECT, errbuf, -1);
366 printf("%s\r\n", errbuf);
377 ret = krb5_verify_authenticator_checksum(context,
384 asprintf(&errbuf, "Bad checksum: %s",
385 krb5_get_err_text(context, ret));
386 Data(ap, KRB_REJECT, errbuf, -1);
388 printf ("%s\r\n", errbuf);
393 ret = krb5_auth_con_getremotesubkey (context,
398 Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
399 auth_finished(ap, AUTH_REJECT);
401 printf("Kerberos V5: "
402 "krb5_auth_con_getremotesubkey failed (%s)\r\n",
403 krb5_get_err_text(context, ret));
407 if (key_block == NULL) {
408 ret = krb5_auth_con_getkey(context,
413 Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
414 auth_finished(ap, AUTH_REJECT);
416 printf("Kerberos V5: "
417 "krb5_auth_con_getkey failed (%s)\r\n",
418 krb5_get_err_text(context, ret));
421 if (key_block == NULL) {
422 Data(ap, KRB_REJECT, "no subkey received", -1);
423 auth_finished(ap, AUTH_REJECT);
425 printf("Kerberos V5: "
426 "krb5_auth_con_getremotesubkey returned NULL key\r\n");
430 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
431 ret = krb5_mk_rep(context, auth_context, &outbuf);
434 "krb5_mk_rep failed", -1);
435 auth_finished(ap, AUTH_REJECT);
437 printf("Kerberos V5: "
438 "krb5_mk_rep failed (%s)\r\n",
439 krb5_get_err_text(context, ret));
442 Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
444 if (krb5_unparse_name(context, ticket->client, &name))
447 if(UserNameRequested && krb5_kuserok(context,
449 UserNameRequested)) {
450 Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
451 if (auth_debug_mode) {
452 printf("Kerberos5 identifies him as ``%s''\r\n",
456 if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
457 key_block->keytype == ETYPE_DES_CBC_MD4 ||
458 key_block->keytype == ETYPE_DES_CBC_CRC) {
463 skey.data = key_block->keyvalue.data;
464 encrypt_session_key(&skey, 0);
470 asprintf (&msg, "user `%s' is not authorized to "
472 name ? name : "<unknown>",
473 UserNameRequested ? UserNameRequested : "<nobody>");
475 Data(ap, KRB_REJECT, NULL, 0);
477 Data(ap, KRB_REJECT, (void *)msg, -1);
480 auth_finished (ap, AUTH_REJECT);
481 krb5_free_keyblock_contents(context, key_block);
484 auth_finished(ap, AUTH_USER);
485 krb5_free_keyblock_contents(context, key_block);
490 char ccname[1024]; /* XXX */
493 inbuf.data = (char *)data;
496 pwd = getpwnam (UserNameRequested);
500 snprintf (ccname, sizeof(ccname),
501 "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
503 ret = krb5_cc_resolve (context, ccname, &ccache);
506 printf ("Kerberos V5: could not get ccache: %s\r\n",
507 krb5_get_err_text(context, ret));
511 ret = krb5_cc_initialize (context,
516 printf ("Kerberos V5: could not init ccache: %s\r\n",
517 krb5_get_err_text(context, ret));
522 esetenv("KRB5CCNAME", ccname, 1);
524 ret = krb5_rd_cred2 (context,
532 "Read forwarded creds failed: %s",
533 krb5_get_err_text (context, ret));
535 Data(ap, KRB_FORWARD_REJECT, NULL, 0);
537 Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
539 printf("Could not read forwarded credentials: %s\r\n",
543 Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
548 chown (ccname + 5, pwd->pw_uid, -1);
550 printf("Forwarded credentials obtained\r\n");
555 printf("Unknown Kerberos option %d\r\n", data[-1]);
556 Data(ap, KRB_REJECT, 0, 0);
562 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
564 static int mutual_complete = 0;
571 printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
574 printf("[ Kerberos V5 refuses authentication ]\r\n");
580 krb5_keyblock *keyblock;
582 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
584 printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
589 printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
591 printf("[ Kerberos V5 accepts you ]\r\n");
593 ret = krb5_auth_con_getlocalsubkey (context,
597 ret = krb5_auth_con_getkey (context,
601 printf("[ krb5_auth_con_getkey: %s ]\r\n",
602 krb5_get_err_text(context, ret));
609 skey.data = keyblock->keyvalue.data;
610 encrypt_session_key(&skey, 0);
611 krb5_free_keyblock_contents (context, keyblock);
612 auth_finished(ap, AUTH_USER);
613 if (forward_flags & OPTS_FORWARD_CREDS)
614 kerberos5_forward(ap);
618 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
619 /* the rest of the reply should contain a krb_ap_rep */
620 krb5_ap_rep_enc_part *reply;
625 inbuf.data = (char *)data;
627 ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
629 printf("[ Mutual authentication failed: %s ]\r\n",
630 krb5_get_err_text (context, ret));
634 krb5_free_ap_rep_enc_part(context, reply);
638 case KRB_FORWARD_ACCEPT:
639 printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
641 case KRB_FORWARD_REJECT:
642 printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
647 printf("Unknown Kerberos option %d\r\n", data[-1]);
653 kerberos5_status(Authenticator *ap __unused, char *name, int level)
655 if (level < AUTH_USER)
658 if (UserNameRequested &&
659 krb5_kuserok(context,
663 strcpy(name, UserNameRequested);
669 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
670 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
673 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
677 buf[buflen-1] = '\0'; /* make sure its NULL terminated */
681 case KRB_REJECT: /* Rejected (reason might follow) */
682 strlcpy((char *)buf, " REJECT ", buflen);
685 case KRB_ACCEPT: /* Accepted (name might follow) */
686 strlcpy((char *)buf, " ACCEPT ", buflen);
691 ADDC(buf, buflen, '"');
692 for (i = 4; i < cnt; i++)
693 ADDC(buf, buflen, data[i]);
694 ADDC(buf, buflen, '"');
695 ADDC(buf, buflen, '\0');
699 case KRB_AUTH: /* Authentication data follows */
700 strlcpy((char *)buf, " AUTH", buflen);
704 strlcpy((char *)buf, " RESPONSE", buflen);
707 case KRB_FORWARD: /* Forwarded credentials follow */
708 strlcpy((char *)buf, " FORWARD", buflen);
711 case KRB_FORWARD_ACCEPT: /* Forwarded credentials accepted */
712 strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
715 case KRB_FORWARD_REJECT: /* Forwarded credentials rejected */
716 /* (reason might follow) */
717 strlcpy((char *)buf, " FORWARD_REJECT", buflen);
721 snprintf(buf, buflen, " %d (unknown)", data[3]);
724 for (i = 4; i < cnt; i++) {
725 snprintf(buf, buflen, " %d", data[i]);
733 kerberos5_forward(Authenticator *ap)
738 krb5_kdc_flags flags;
740 krb5_principal principal;
742 ret = krb5_cc_default (context, &ccache);
745 printf ("KerberosV5: could not get default ccache: %s\r\n",
746 krb5_get_err_text (context, ret));
750 ret = krb5_cc_get_principal (context, ccache, &principal);
753 printf ("KerberosV5: could not get principal: %s\r\n",
754 krb5_get_err_text (context, ret));
758 memset (&creds, 0, sizeof(creds));
760 creds.client = principal;
762 ret = krb5_build_principal (context,
764 strlen(principal->realm),
772 printf ("KerberosV5: could not get principal: %s\r\n",
773 krb5_get_err_text (context, ret));
777 creds.times.endtime = 0;
780 flags.b.forwarded = 1;
781 if (forward_flags & OPTS_FORWARDABLE_CREDS)
782 flags.b.forwardable = 1;
784 ret = krb5_get_forwarded_creds (context,
793 printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
794 krb5_get_err_text (context, ret));
798 if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
800 printf("Not enough room for authentication data\r\n");
803 printf("Forwarded local Kerberos V5 credentials to server\r\n");
808 /* if this was a K5 authentication try and join a PAG for the user. */
810 kerberos5_dfspag(void)
813 dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,