2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
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13 * 3. All advertising materials mentioning features or use of this software
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15 * This product includes software developed by the University of
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18 * may be used to endorse or promote products derived from this software
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29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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35 * Copyright (C) 1990 by the Massachusetts Institute of Technology
37 * Export of this software from the United States of America may
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40 * export to obtain such a license before exporting.
42 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
43 * distribute this software and its documentation for any purpose and
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56 RCSID("$Id: kerberos5.c,v 1.51.4.1 2002/10/21 14:28:31 joda Exp $");
60 #include <arpa/telnet.h>
68 #define Authenticator k5_Authenticator
87 int forward_flags = 0; /* Flags get set in telnet/main.c on -f and -F */
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
98 void kerberos5_forward (Authenticator *);
100 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
101 AUTHTYPE_KERBEROS_V5, };
103 #define KRB_AUTH 0 /* Authentication data follows */
104 #define KRB_REJECT 1 /* Rejected (reason might follow) */
105 #define KRB_ACCEPT 2 /* Accepted */
106 #define KRB_RESPONSE 3 /* Response for mutual auth. */
108 #define KRB_FORWARD 4 /* Forwarded credentials follow */
109 #define KRB_FORWARD_ACCEPT 5 /* Forwarded credentials accepted */
110 #define KRB_FORWARD_REJECT 6 /* Forwarded credentials rejected */
112 static krb5_data auth;
113 static krb5_ticket *ticket;
115 static krb5_context context;
116 static krb5_auth_context auth_context;
119 Data(Authenticator *ap, int type, void *d, int c)
121 unsigned char *p = str_data + 4;
122 unsigned char *cd = (unsigned char *)d;
125 c = strlen((char*)cd);
127 if (auth_debug_mode) {
128 printf("%s:%d: [%d] (%d)",
129 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
139 if ((*p++ = *cd++) == IAC)
144 if (str_data[3] == TELQUAL_IS)
145 printsub('>', &str_data[2], p - &str_data[2]);
146 return(telnet_net_write(str_data, p - str_data));
150 kerberos5_init(Authenticator *ap, int server)
154 ret = krb5_init_context(&context);
159 krb5_kt_cursor cursor;
161 ret = krb5_kt_default(context, &kt);
165 ret = krb5_kt_start_seq_get (context, kt, &cursor);
167 krb5_kt_close (context, kt);
170 krb5_kt_end_seq_get (context, kt, &cursor);
171 krb5_kt_close (context, kt);
173 str_data[3] = TELQUAL_REPLY;
175 str_data[3] = TELQUAL_IS;
181 kerberos5_send(char *name, Authenticator *ap)
186 krb5_data cksum_data;
189 if (!UserNameRequested) {
190 if (auth_debug_mode) {
191 printf("Kerberos V5: no user name supplied\r\n");
196 ret = krb5_cc_default(context, &ccache);
198 if (auth_debug_mode) {
199 printf("Kerberos V5: could not get default ccache: %s\r\n",
200 krb5_get_err_text (context, ret));
205 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
206 ap_opts = AP_OPTS_MUTUAL_REQUIRED;
210 ap_opts |= AP_OPTS_USE_SUBKEY;
212 ret = krb5_auth_con_init (context, &auth_context);
214 if (auth_debug_mode) {
215 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
216 krb5_get_err_text(context, ret));
221 ret = krb5_auth_con_setaddrs_from_fd (context,
225 if (auth_debug_mode) {
226 printf ("Kerberos V5:"
227 " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
228 krb5_get_err_text(context, ret));
233 krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
238 cksum_data.length = sizeof(foo);
239 cksum_data.data = foo;
243 krb5_principal service;
247 ret = krb5_sname_to_principal (context,
253 if (auth_debug_mode) {
254 printf ("Kerberos V5:"
255 " krb5_sname_to_principal(%s) failed (%s)\r\n",
256 RemoteHostName, krb5_get_err_text(context, ret));
260 ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
262 if (auth_debug_mode) {
263 printf ("Kerberos V5:"
264 " krb5_unparse_name_fixed failed (%s)\r\n",
265 krb5_get_err_text(context, ret));
269 printf("[ Trying %s (%s)... ]\r\n", name, sname);
270 ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
272 &cksum_data, ccache, &auth);
273 krb5_free_principal (context, service);
277 if (1 || auth_debug_mode) {
278 printf("Kerberos V5: mk_req failed (%s)\r\n",
279 krb5_get_err_text(context, ret));
284 if (!auth_sendname((unsigned char *)UserNameRequested,
285 strlen(UserNameRequested))) {
287 printf("Not enough room for user name\r\n");
290 if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
292 printf("Not enough room for authentication data\r\n");
295 if (auth_debug_mode) {
296 printf("Sent Kerberos V5 credentials to server\r\n");
302 kerberos5_send_mutual(Authenticator *ap)
304 return kerberos5_send("mutual KERBEROS5", ap);
308 kerberos5_send_oneway(Authenticator *ap)
310 return kerberos5_send("KERBEROS5", ap);
314 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
318 krb5_keyblock *key_block;
320 krb5_principal server;
327 auth.data = (char *)data;
332 ret = krb5_auth_con_init (context, &auth_context);
334 Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
335 auth_finished(ap, AUTH_REJECT);
337 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
338 krb5_get_err_text(context, ret));
342 ret = krb5_auth_con_setaddrs_from_fd (context,
346 Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
347 auth_finished(ap, AUTH_REJECT);
349 printf("Kerberos V5: "
350 "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
351 krb5_get_err_text(context, ret));
355 ret = krb5_sock_to_principal (context,
361 Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
362 auth_finished(ap, AUTH_REJECT);
364 printf("Kerberos V5: "
365 "krb5_sock_to_principal failed (%s)\r\n",
366 krb5_get_err_text(context, ret));
370 ret = krb5_rd_req(context,
378 krb5_free_principal (context, server);
383 "Read req failed: %s",
384 krb5_get_err_text(context, ret));
385 Data(ap, KRB_REJECT, errbuf, -1);
387 printf("%s\r\n", errbuf);
398 ret = krb5_verify_authenticator_checksum(context,
405 asprintf(&errbuf, "Bad checksum: %s",
406 krb5_get_err_text(context, ret));
407 Data(ap, KRB_REJECT, errbuf, -1);
409 printf ("%s\r\n", errbuf);
414 ret = krb5_auth_con_getremotesubkey (context,
419 Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
420 auth_finished(ap, AUTH_REJECT);
422 printf("Kerberos V5: "
423 "krb5_auth_con_getremotesubkey failed (%s)\r\n",
424 krb5_get_err_text(context, ret));
428 if (key_block == NULL) {
429 ret = krb5_auth_con_getkey(context,
434 Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
435 auth_finished(ap, AUTH_REJECT);
437 printf("Kerberos V5: "
438 "krb5_auth_con_getkey failed (%s)\r\n",
439 krb5_get_err_text(context, ret));
442 if (key_block == NULL) {
443 Data(ap, KRB_REJECT, "no subkey received", -1);
444 auth_finished(ap, AUTH_REJECT);
446 printf("Kerberos V5: "
447 "krb5_auth_con_getremotesubkey returned NULL key\r\n");
451 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
452 ret = krb5_mk_rep(context, auth_context, &outbuf);
455 "krb5_mk_rep failed", -1);
456 auth_finished(ap, AUTH_REJECT);
458 printf("Kerberos V5: "
459 "krb5_mk_rep failed (%s)\r\n",
460 krb5_get_err_text(context, ret));
463 Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
465 if (krb5_unparse_name(context, ticket->client, &name))
468 if(UserNameRequested && krb5_kuserok(context,
470 UserNameRequested)) {
471 Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
472 if (auth_debug_mode) {
473 printf("Kerberos5 identifies him as ``%s''\r\n",
477 if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
478 key_block->keytype == ETYPE_DES_CBC_MD4 ||
479 key_block->keytype == ETYPE_DES_CBC_CRC) {
484 skey.data = key_block->keyvalue.data;
485 encrypt_session_key(&skey, 0);
491 asprintf (&msg, "user `%s' is not authorized to "
493 name ? name : "<unknown>",
494 UserNameRequested ? UserNameRequested : "<nobody>");
496 Data(ap, KRB_REJECT, NULL, 0);
498 Data(ap, KRB_REJECT, (void *)msg, -1);
501 auth_finished (ap, AUTH_REJECT);
502 krb5_free_keyblock_contents(context, key_block);
505 auth_finished(ap, AUTH_USER);
506 krb5_free_keyblock_contents(context, key_block);
511 char ccname[1024]; /* XXX */
514 inbuf.data = (char *)data;
517 pwd = getpwnam (UserNameRequested);
521 snprintf (ccname, sizeof(ccname),
522 "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
524 ret = krb5_cc_resolve (context, ccname, &ccache);
527 printf ("Kerberos V5: could not get ccache: %s\r\n",
528 krb5_get_err_text(context, ret));
532 ret = krb5_cc_initialize (context,
537 printf ("Kerberos V5: could not init ccache: %s\r\n",
538 krb5_get_err_text(context, ret));
543 esetenv("KRB5CCNAME", ccname, 1);
545 ret = krb5_rd_cred2 (context,
553 "Read forwarded creds failed: %s",
554 krb5_get_err_text (context, ret));
556 Data(ap, KRB_FORWARD_REJECT, NULL, 0);
558 Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
560 printf("Could not read forwarded credentials: %s\r\n",
564 Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
569 chown (ccname + 5, pwd->pw_uid, -1);
571 printf("Forwarded credentials obtained\r\n");
576 printf("Unknown Kerberos option %d\r\n", data[-1]);
577 Data(ap, KRB_REJECT, 0, 0);
583 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
585 static int mutual_complete = 0;
592 printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
595 printf("[ Kerberos V5 refuses authentication ]\r\n");
601 krb5_keyblock *keyblock;
603 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
605 printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
610 printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
612 printf("[ Kerberos V5 accepts you ]\r\n");
614 ret = krb5_auth_con_getlocalsubkey (context,
618 ret = krb5_auth_con_getkey (context,
622 printf("[ krb5_auth_con_getkey: %s ]\r\n",
623 krb5_get_err_text(context, ret));
630 skey.data = keyblock->keyvalue.data;
631 encrypt_session_key(&skey, 0);
632 krb5_free_keyblock_contents (context, keyblock);
633 auth_finished(ap, AUTH_USER);
634 if (forward_flags & OPTS_FORWARD_CREDS)
635 kerberos5_forward(ap);
639 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
640 /* the rest of the reply should contain a krb_ap_rep */
641 krb5_ap_rep_enc_part *reply;
646 inbuf.data = (char *)data;
648 ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
650 printf("[ Mutual authentication failed: %s ]\r\n",
651 krb5_get_err_text (context, ret));
655 krb5_free_ap_rep_enc_part(context, reply);
659 case KRB_FORWARD_ACCEPT:
660 printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
662 case KRB_FORWARD_REJECT:
663 printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
668 printf("Unknown Kerberos option %d\r\n", data[-1]);
674 kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
676 if (level < AUTH_USER)
679 if (UserNameRequested &&
680 krb5_kuserok(context,
684 strlcpy(name, UserNameRequested, name_sz);
693 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
694 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
697 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
701 buf[buflen-1] = '\0'; /* make sure its NULL terminated */
705 case KRB_REJECT: /* Rejected (reason might follow) */
706 strlcpy((char *)buf, " REJECT ", buflen);
709 case KRB_ACCEPT: /* Accepted (name might follow) */
710 strlcpy((char *)buf, " ACCEPT ", buflen);
715 ADDC(buf, buflen, '"');
716 for (i = 4; i < cnt; i++)
717 ADDC(buf, buflen, data[i]);
718 ADDC(buf, buflen, '"');
719 ADDC(buf, buflen, '\0');
723 case KRB_AUTH: /* Authentication data follows */
724 strlcpy((char *)buf, " AUTH", buflen);
728 strlcpy((char *)buf, " RESPONSE", buflen);
731 case KRB_FORWARD: /* Forwarded credentials follow */
732 strlcpy((char *)buf, " FORWARD", buflen);
735 case KRB_FORWARD_ACCEPT: /* Forwarded credentials accepted */
736 strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
739 case KRB_FORWARD_REJECT: /* Forwarded credentials rejected */
740 /* (reason might follow) */
741 strlcpy((char *)buf, " FORWARD_REJECT", buflen);
745 snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
748 for (i = 4; i < cnt; i++) {
749 snprintf((char*)buf, buflen, " %d", data[i]);
757 kerberos5_forward(Authenticator *ap)
762 krb5_kdc_flags flags;
764 krb5_principal principal;
766 ret = krb5_cc_default (context, &ccache);
769 printf ("KerberosV5: could not get default ccache: %s\r\n",
770 krb5_get_err_text (context, ret));
774 ret = krb5_cc_get_principal (context, ccache, &principal);
777 printf ("KerberosV5: could not get principal: %s\r\n",
778 krb5_get_err_text (context, ret));
782 memset (&creds, 0, sizeof(creds));
784 creds.client = principal;
786 ret = krb5_build_principal (context,
788 strlen(principal->realm),
796 printf ("KerberosV5: could not get principal: %s\r\n",
797 krb5_get_err_text (context, ret));
801 creds.times.endtime = 0;
804 flags.b.forwarded = 1;
805 if (forward_flags & OPTS_FORWARDABLE_CREDS)
806 flags.b.forwardable = 1;
808 ret = krb5_get_forwarded_creds (context,
817 printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
818 krb5_get_err_text (context, ret));
822 if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
824 printf("Not enough room for authentication data\r\n");
827 printf("Forwarded local Kerberos V5 credentials to server\r\n");
832 /* if this was a K5 authentication try and join a PAG for the user. */
834 kerberos5_dfspag(void)
837 dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
844 kerberos5_set_forward(int on)
847 forward_flags &= ~OPTS_FORWARD_CREDS;
849 forward_flags |= OPTS_FORWARD_CREDS;
851 forward_flags ^= OPTS_FORWARD_CREDS;
856 kerberos5_set_forwardable(int on)
859 forward_flags &= ~OPTS_FORWARDABLE_CREDS;
861 forward_flags |= OPTS_FORWARDABLE_CREDS;
863 forward_flags ^= OPTS_FORWARDABLE_CREDS;