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37 * Export of this software from the United States of America may
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56 RCSID("$Id: kerberos5.c,v 1.53.2.1 2004/06/21 08:21:07 lha 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[4] = { IAC, SB, TELOPT_AUTHENTICATION, 0 };
102 #define KRB_AUTH 0 /* Authentication data follows */
103 #define KRB_REJECT 1 /* Rejected (reason might follow) */
104 #define KRB_ACCEPT 2 /* Accepted */
105 #define KRB_RESPONSE 3 /* Response for mutual auth. */
107 #define KRB_FORWARD 4 /* Forwarded credentials follow */
108 #define KRB_FORWARD_ACCEPT 5 /* Forwarded credentials accepted */
109 #define KRB_FORWARD_REJECT 6 /* Forwarded credentials rejected */
111 static krb5_data auth;
112 static krb5_ticket *ticket;
114 static krb5_context context;
115 static krb5_auth_context auth_context;
118 Data(Authenticator *ap, int type, void *d, int c)
120 unsigned char *cd = (unsigned char *)d;
121 unsigned char *p0, *p;
122 size_t len = sizeof(str_data) + 3 + 2;
126 c = strlen((char*)cd);
128 for (p = cd; p - cd < c; p++, len++)
136 memcpy(p0, str_data, sizeof(str_data));
137 p = p0 + sizeof(str_data);
139 if (auth_debug_mode) {
140 printf("%s:%d: [%d] (%d)",
141 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
151 if ((*p++ = *cd++) == IAC)
156 if (str_data[3] == TELQUAL_IS)
157 printsub('>', &p0[2], len - 2);
158 ret = telnet_net_write(p0, len);
164 kerberos5_init(Authenticator *ap, int server)
168 ret = krb5_init_context(&context);
173 krb5_kt_cursor cursor;
175 ret = krb5_kt_default(context, &kt);
179 ret = krb5_kt_start_seq_get (context, kt, &cursor);
181 krb5_kt_close (context, kt);
184 krb5_kt_end_seq_get (context, kt, &cursor);
185 krb5_kt_close (context, kt);
187 str_data[3] = TELQUAL_REPLY;
189 str_data[3] = TELQUAL_IS;
195 kerberos5_send(char *name, Authenticator *ap)
200 krb5_data cksum_data;
203 if (!UserNameRequested) {
204 if (auth_debug_mode) {
205 printf("Kerberos V5: no user name supplied\r\n");
210 ret = krb5_cc_default(context, &ccache);
212 if (auth_debug_mode) {
213 printf("Kerberos V5: could not get default ccache: %s\r\n",
214 krb5_get_err_text (context, ret));
219 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
220 ap_opts = AP_OPTS_MUTUAL_REQUIRED;
224 ap_opts |= AP_OPTS_USE_SUBKEY;
226 ret = krb5_auth_con_init (context, &auth_context);
228 if (auth_debug_mode) {
229 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
230 krb5_get_err_text(context, ret));
235 ret = krb5_auth_con_setaddrs_from_fd (context,
239 if (auth_debug_mode) {
240 printf ("Kerberos V5:"
241 " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
242 krb5_get_err_text(context, ret));
247 krb5_auth_con_setkeytype (context, auth_context, KEYTYPE_DES);
252 cksum_data.length = sizeof(foo);
253 cksum_data.data = foo;
257 krb5_principal service;
261 ret = krb5_sname_to_principal (context,
267 if (auth_debug_mode) {
268 printf ("Kerberos V5:"
269 " krb5_sname_to_principal(%s) failed (%s)\r\n",
270 RemoteHostName, krb5_get_err_text(context, ret));
274 ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
276 if (auth_debug_mode) {
277 printf ("Kerberos V5:"
278 " krb5_unparse_name_fixed failed (%s)\r\n",
279 krb5_get_err_text(context, ret));
283 printf("[ Trying %s (%s)... ]\r\n", name, sname);
284 ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
286 &cksum_data, ccache, &auth);
287 krb5_free_principal (context, service);
291 if (1 || auth_debug_mode) {
292 printf("Kerberos V5: mk_req failed (%s)\r\n",
293 krb5_get_err_text(context, ret));
298 if (!auth_sendname((unsigned char *)UserNameRequested,
299 strlen(UserNameRequested))) {
301 printf("Not enough room for user name\r\n");
304 if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
306 printf("Not enough room for authentication data\r\n");
309 if (auth_debug_mode) {
310 printf("Sent Kerberos V5 credentials to server\r\n");
316 kerberos5_send_mutual(Authenticator *ap)
318 return kerberos5_send("mutual KERBEROS5", ap);
322 kerberos5_send_oneway(Authenticator *ap)
324 return kerberos5_send("KERBEROS5", ap);
328 kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
332 krb5_keyblock *key_block;
334 krb5_principal server;
341 auth.data = (char *)data;
346 ret = krb5_auth_con_init (context, &auth_context);
348 Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
349 auth_finished(ap, AUTH_REJECT);
351 printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
352 krb5_get_err_text(context, ret));
356 ret = krb5_auth_con_setaddrs_from_fd (context,
360 Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
361 auth_finished(ap, AUTH_REJECT);
363 printf("Kerberos V5: "
364 "krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
365 krb5_get_err_text(context, ret));
369 ret = krb5_sock_to_principal (context,
375 Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
376 auth_finished(ap, AUTH_REJECT);
378 printf("Kerberos V5: "
379 "krb5_sock_to_principal failed (%s)\r\n",
380 krb5_get_err_text(context, ret));
384 ret = krb5_rd_req(context,
392 krb5_free_principal (context, server);
397 "Read req failed: %s",
398 krb5_get_err_text(context, ret));
399 Data(ap, KRB_REJECT, errbuf, -1);
401 printf("%s\r\n", errbuf);
412 ret = krb5_verify_authenticator_checksum(context,
419 asprintf(&errbuf, "Bad checksum: %s",
420 krb5_get_err_text(context, ret));
421 Data(ap, KRB_REJECT, errbuf, -1);
423 printf ("%s\r\n", errbuf);
428 ret = krb5_auth_con_getremotesubkey (context,
433 Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
434 auth_finished(ap, AUTH_REJECT);
436 printf("Kerberos V5: "
437 "krb5_auth_con_getremotesubkey failed (%s)\r\n",
438 krb5_get_err_text(context, ret));
442 if (key_block == NULL) {
443 ret = krb5_auth_con_getkey(context,
448 Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
449 auth_finished(ap, AUTH_REJECT);
451 printf("Kerberos V5: "
452 "krb5_auth_con_getkey failed (%s)\r\n",
453 krb5_get_err_text(context, ret));
456 if (key_block == NULL) {
457 Data(ap, KRB_REJECT, "no subkey received", -1);
458 auth_finished(ap, AUTH_REJECT);
460 printf("Kerberos V5: "
461 "krb5_auth_con_getremotesubkey returned NULL key\r\n");
465 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
466 ret = krb5_mk_rep(context, auth_context, &outbuf);
469 "krb5_mk_rep failed", -1);
470 auth_finished(ap, AUTH_REJECT);
472 printf("Kerberos V5: "
473 "krb5_mk_rep failed (%s)\r\n",
474 krb5_get_err_text(context, ret));
477 Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
479 if (krb5_unparse_name(context, ticket->client, &name))
482 if(UserNameRequested && krb5_kuserok(context,
484 UserNameRequested)) {
485 Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
486 if (auth_debug_mode) {
487 printf("Kerberos5 identifies him as ``%s''\r\n",
491 if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
492 key_block->keytype == ETYPE_DES_CBC_MD4 ||
493 key_block->keytype == ETYPE_DES_CBC_CRC) {
498 skey.data = key_block->keyvalue.data;
499 encrypt_session_key(&skey, 0);
505 asprintf (&msg, "user `%s' is not authorized to "
507 name ? name : "<unknown>",
508 UserNameRequested ? UserNameRequested : "<nobody>");
510 Data(ap, KRB_REJECT, NULL, 0);
512 Data(ap, KRB_REJECT, (void *)msg, -1);
515 auth_finished (ap, AUTH_REJECT);
516 krb5_free_keyblock_contents(context, key_block);
519 auth_finished(ap, AUTH_USER);
520 krb5_free_keyblock_contents(context, key_block);
525 char ccname[1024]; /* XXX */
528 inbuf.data = (char *)data;
531 pwd = getpwnam (UserNameRequested);
535 snprintf (ccname, sizeof(ccname),
536 "FILE:/tmp/krb5cc_%u", pwd->pw_uid);
538 ret = krb5_cc_resolve (context, ccname, &ccache);
541 printf ("Kerberos V5: could not get ccache: %s\r\n",
542 krb5_get_err_text(context, ret));
546 ret = krb5_cc_initialize (context,
551 printf ("Kerberos V5: could not init ccache: %s\r\n",
552 krb5_get_err_text(context, ret));
557 esetenv("KRB5CCNAME", ccname, 1);
559 ret = krb5_rd_cred2 (context,
567 "Read forwarded creds failed: %s",
568 krb5_get_err_text (context, ret));
570 Data(ap, KRB_FORWARD_REJECT, NULL, 0);
572 Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
574 printf("Could not read forwarded credentials: %s\r\n",
578 Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
583 chown (ccname + 5, pwd->pw_uid, -1);
585 printf("Forwarded credentials obtained\r\n");
590 printf("Unknown Kerberos option %d\r\n", data[-1]);
591 Data(ap, KRB_REJECT, 0, 0);
597 kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
599 static int mutual_complete = 0;
606 printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
609 printf("[ Kerberos V5 refuses authentication ]\r\n");
615 krb5_keyblock *keyblock;
617 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
619 printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
624 printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
626 printf("[ Kerberos V5 accepts you ]\r\n");
628 ret = krb5_auth_con_getlocalsubkey (context,
632 ret = krb5_auth_con_getkey (context,
636 printf("[ krb5_auth_con_getkey: %s ]\r\n",
637 krb5_get_err_text(context, ret));
644 skey.data = keyblock->keyvalue.data;
645 encrypt_session_key(&skey, 0);
646 krb5_free_keyblock_contents (context, keyblock);
647 auth_finished(ap, AUTH_USER);
648 if (forward_flags & OPTS_FORWARD_CREDS)
649 kerberos5_forward(ap);
653 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
654 /* the rest of the reply should contain a krb_ap_rep */
655 krb5_ap_rep_enc_part *reply;
660 inbuf.data = (char *)data;
662 ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
664 printf("[ Mutual authentication failed: %s ]\r\n",
665 krb5_get_err_text (context, ret));
669 krb5_free_ap_rep_enc_part(context, reply);
673 case KRB_FORWARD_ACCEPT:
674 printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
676 case KRB_FORWARD_REJECT:
677 printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
682 printf("Unknown Kerberos option %d\r\n", data[-1]);
688 kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
690 if (level < AUTH_USER)
693 if (UserNameRequested &&
694 krb5_kuserok(context,
698 strlcpy(name, UserNameRequested, name_sz);
707 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
708 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
711 kerberos5_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
715 buf[buflen-1] = '\0'; /* make sure its NULL terminated */
719 case KRB_REJECT: /* Rejected (reason might follow) */
720 strlcpy((char *)buf, " REJECT ", buflen);
723 case KRB_ACCEPT: /* Accepted (name might follow) */
724 strlcpy((char *)buf, " ACCEPT ", buflen);
729 ADDC(buf, buflen, '"');
730 for (i = 4; i < cnt; i++)
731 ADDC(buf, buflen, data[i]);
732 ADDC(buf, buflen, '"');
733 ADDC(buf, buflen, '\0');
737 case KRB_AUTH: /* Authentication data follows */
738 strlcpy((char *)buf, " AUTH", buflen);
742 strlcpy((char *)buf, " RESPONSE", buflen);
745 case KRB_FORWARD: /* Forwarded credentials follow */
746 strlcpy((char *)buf, " FORWARD", buflen);
749 case KRB_FORWARD_ACCEPT: /* Forwarded credentials accepted */
750 strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
753 case KRB_FORWARD_REJECT: /* Forwarded credentials rejected */
754 /* (reason might follow) */
755 strlcpy((char *)buf, " FORWARD_REJECT", buflen);
759 snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
762 for (i = 4; i < cnt; i++) {
763 snprintf((char*)buf, buflen, " %d", data[i]);
771 kerberos5_forward(Authenticator *ap)
776 krb5_kdc_flags flags;
778 krb5_principal principal;
780 ret = krb5_cc_default (context, &ccache);
783 printf ("KerberosV5: could not get default ccache: %s\r\n",
784 krb5_get_err_text (context, ret));
788 ret = krb5_cc_get_principal (context, ccache, &principal);
791 printf ("KerberosV5: could not get principal: %s\r\n",
792 krb5_get_err_text (context, ret));
796 memset (&creds, 0, sizeof(creds));
798 creds.client = principal;
800 ret = krb5_build_principal (context,
802 strlen(principal->realm),
810 printf ("KerberosV5: could not get principal: %s\r\n",
811 krb5_get_err_text (context, ret));
815 creds.times.endtime = 0;
818 flags.b.forwarded = 1;
819 if (forward_flags & OPTS_FORWARDABLE_CREDS)
820 flags.b.forwardable = 1;
822 ret = krb5_get_forwarded_creds (context,
831 printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
832 krb5_get_err_text (context, ret));
836 if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
838 printf("Not enough room for authentication data\r\n");
841 printf("Forwarded local Kerberos V5 credentials to server\r\n");
846 /* if this was a K5 authentication try and join a PAG for the user. */
848 kerberos5_dfspag(void)
851 dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
858 kerberos5_set_forward(int on)
861 forward_flags &= ~OPTS_FORWARD_CREDS;
863 forward_flags |= OPTS_FORWARD_CREDS;
865 forward_flags ^= OPTS_FORWARD_CREDS;
870 kerberos5_set_forwardable(int on)
873 forward_flags &= ~OPTS_FORWARDABLE_CREDS;
875 forward_flags |= OPTS_FORWARDABLE_CREDS;
877 forward_flags ^= OPTS_FORWARDABLE_CREDS;