2 Unix SMB/CIFS implementation.
3 kerberos utility library
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Remus Koos 2001
6 Copyright (C) Luke Howard 2003
7 Copyright (C) Guenther Deschner 2003, 2005
8 Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
9 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
10 Copyright (C) Jeremy Allison 2007
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 3 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
30 #if !defined(HAVE_KRB5_PRINC_COMPONENT)
31 const krb5_data *krb5_princ_component(krb5_context, krb5_principal, int );
34 static bool ads_dedicated_keytab_verify_ticket(krb5_context context,
35 krb5_auth_context auth_context,
36 const DATA_BLOB *ticket,
38 krb5_keyblock **keyblock,
39 krb5_error_code *perr)
41 krb5_error_code ret = 0;
43 krb5_keytab keytab = NULL;
44 krb5_keytab_entry kt_entry;
45 krb5_ticket *dec_ticket = NULL;
53 ZERO_STRUCT(kt_entry);
55 ret = smb_krb5_open_keytab(context, lp_dedicated_keytab_file(), true,
58 DEBUG(1, ("smb_krb5_open_keytab failed (%s)\n",
63 packet.length = ticket->length;
64 packet.data = (char *)ticket->data;
67 ret = krb5_rd_req(context, &auth_context, &packet, NULL, keytab,
70 DEBUG(0, ("krb5_rd_req failed (%s)\n", error_message(ret)));
74 /* Get the key for checking the pac signature */
75 ret = krb5_kt_get_entry(context, keytab, dec_ticket->server,
76 dec_ticket->enc_part.kvno, dec_ticket->enc_part.enctype,
79 DEBUG(0, ("krb5_kt_get_entry failed (%s)\n",
84 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK /* Heimdal */
85 ret = krb5_copy_keyblock(context, &kt_entry.keyblock, keyblock);
86 #elif defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) /* MIT */
87 ret = krb5_copy_keyblock(context, &kt_entry.key, keyblock);
89 #error UNKNOWN_KRB5_KEYTAB_ENTRY_FORMAT
91 smb_krb5_kt_free_entry(context, &kt_entry);
94 DEBUG(0, ("failed to copy key: %s\n",
100 *pp_tkt = dec_ticket;
105 krb5_free_ticket(context, dec_ticket);
108 krb5_kt_close(context, keytab);
114 /**********************************************************************************
115 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
116 it's more like what microsoft does... see comment in utils/net_ads.c in the
117 ads_keytab_add_entry function for details.
118 ***********************************************************************************/
120 static bool ads_keytab_verify_ticket(krb5_context context,
121 krb5_auth_context auth_context,
122 const DATA_BLOB *ticket,
123 krb5_ticket **pp_tkt,
124 krb5_keyblock **keyblock,
125 krb5_error_code *perr)
127 krb5_error_code ret = 0;
128 bool auth_ok = False;
129 krb5_keytab keytab = NULL;
130 krb5_kt_cursor kt_cursor;
131 krb5_keytab_entry kt_entry;
132 char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
133 char *entry_princ_s = NULL;
134 fstring my_name, my_fqdn;
136 int number_matched_principals = 0;
143 /* Generate the list of principal names which we expect
144 * clients might want to use for authenticating to the file
145 * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
147 fstrcpy(my_name, global_myname());
150 name_to_fqdn(my_fqdn, global_myname());
152 if (asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm()) == -1) {
155 if (asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm()) == -1) {
158 if (asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm()) == -1) {
161 if (asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm()) == -1) {
164 if (asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm()) == -1) {
167 if (asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm()) == -1) {
170 if (asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm()) == -1) {
174 ZERO_STRUCT(kt_entry);
175 ZERO_STRUCT(kt_cursor);
177 ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
179 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
183 /* Iterate through the keytab. For each key, if the principal
184 * name case-insensitively matches one of the allowed formats,
185 * try verifying the ticket using that principal. */
187 ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
189 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
193 while (!auth_ok && (krb5_kt_next_entry(context, keytab, &kt_entry, &kt_cursor) == 0)) {
194 ret = smb_krb5_unparse_name(context, kt_entry.principal, &entry_princ_s);
196 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
197 error_message(ret)));
201 for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
203 if (!strequal(entry_princ_s, valid_princ_formats[i])) {
207 number_matched_principals++;
208 packet.length = ticket->length;
209 packet.data = (char *)ticket->data;
212 ret = krb5_rd_req_return_keyblock_from_keytab(context, &auth_context, &packet,
213 kt_entry.principal, keytab,
214 NULL, pp_tkt, keyblock);
217 DEBUG(10,("ads_keytab_verify_ticket: "
218 "krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
219 entry_princ_s, error_message(ret)));
221 /* workaround for MIT:
222 * as krb5_ktfile_get_entry will explicitly
223 * close the krb5_keytab as soon as krb5_rd_req
224 * has successfully decrypted the ticket but the
225 * ticket is not valid yet (due to clockskew)
226 * there is no point in querying more keytab
227 * entries - Guenther */
229 if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
230 ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
231 ret == KRB5KRB_AP_ERR_SKEW) {
235 DEBUG(3,("ads_keytab_verify_ticket: "
236 "krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
243 /* Free the name we parsed. */
244 SAFE_FREE(entry_princ_s);
246 /* Free the entry we just read. */
247 smb_krb5_kt_free_entry(context, &kt_entry);
248 ZERO_STRUCT(kt_entry);
250 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
252 ZERO_STRUCT(kt_cursor);
256 for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
257 SAFE_FREE(valid_princ_formats[i]);
261 if (!number_matched_principals) {
262 DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
264 DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
265 number_matched_principals));
269 SAFE_FREE(entry_princ_s);
272 krb5_keytab_entry zero_kt_entry;
273 ZERO_STRUCT(zero_kt_entry);
274 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
275 smb_krb5_kt_free_entry(context, &kt_entry);
280 krb5_kt_cursor zero_csr;
281 ZERO_STRUCT(zero_csr);
282 if ((memcmp(&kt_cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
283 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
288 krb5_kt_close(context, keytab);
294 /**********************************************************************************
295 Try to verify a ticket using the secrets.tdb.
296 ***********************************************************************************/
298 static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
299 krb5_auth_context auth_context,
300 krb5_principal host_princ,
301 const DATA_BLOB *ticket,
302 krb5_ticket **pp_tkt,
303 krb5_keyblock **keyblock,
304 krb5_error_code *perr)
306 krb5_error_code ret = 0;
307 bool auth_ok = False;
308 char *password_s = NULL;
310 krb5_enctype enctypes[] = {
311 #if defined(ENCTYPE_ARCFOUR_HMAC)
312 ENCTYPE_ARCFOUR_HMAC,
326 if (!secrets_init()) {
327 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
328 *perr = KRB5_CONFIG_CANTOPEN;
332 password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
334 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
335 *perr = KRB5_LIBOS_CANTREADPWD;
339 password.data = password_s;
340 password.length = strlen(password_s);
342 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
344 packet.length = ticket->length;
345 packet.data = (char *)ticket->data;
347 /* We need to setup a auth context with each possible encoding type in turn. */
348 for (i=0;enctypes[i];i++) {
349 krb5_keyblock *key = NULL;
351 if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
356 if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i], false)) {
361 krb5_auth_con_setuseruserkey(context, auth_context, key);
363 if (!(ret = krb5_rd_req(context, &auth_context, &packet,
365 NULL, NULL, pp_tkt))) {
366 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
367 (unsigned int)enctypes[i] ));
369 krb5_copy_keyblock(context, key, keyblock);
370 krb5_free_keyblock(context, key);
374 DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
375 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
376 (unsigned int)enctypes[i], error_message(ret)));
378 /* successfully decrypted but ticket is just not valid at the moment */
379 if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
380 ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
381 ret == KRB5KRB_AP_ERR_SKEW) {
382 krb5_free_keyblock(context, key);
386 krb5_free_keyblock(context, key);
391 SAFE_FREE(password_s);
396 /**********************************************************************************
397 Verify an incoming ticket and parse out the principal name and
398 authorization_data if available.
399 ***********************************************************************************/
401 NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
404 const DATA_BLOB *ticket,
406 struct PAC_DATA **pac_data,
408 DATA_BLOB *session_key,
409 bool use_replay_cache)
411 NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
414 krb5_context context = NULL;
415 krb5_auth_context auth_context = NULL;
417 krb5_ticket *tkt = NULL;
418 krb5_rcache rcache = NULL;
419 krb5_keyblock *keyblock = NULL;
421 krb5_error_code ret = 0;
423 krb5_principal host_princ = NULL;
424 krb5_const_principal client_principal = NULL;
425 char *host_princ_s = NULL;
426 bool auth_ok = False;
427 bool got_auth_data = False;
428 struct named_mutex *mutex = NULL;
431 ZERO_STRUCT(auth_data);
435 *ap_rep = data_blob_null;
436 *session_key = data_blob_null;
438 initialize_krb5_error_table();
439 ret = krb5_init_context(&context);
441 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
442 return NT_STATUS_LOGON_FAILURE;
445 if (time_offset != 0) {
446 krb5_set_real_time(context, time(NULL) + time_offset, 0);
449 ret = krb5_set_default_realm(context, realm);
451 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
455 /* This whole process is far more complex than I would
456 like. We have to go through all this to allow us to store
457 the secret internally, instead of using /etc/krb5.keytab */
459 ret = krb5_auth_con_init(context, &auth_context);
461 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
465 krb5_auth_con_getflags( context, auth_context, &flags );
466 if ( !use_replay_cache ) {
467 /* Disable default use of a replay cache */
468 flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
469 krb5_auth_con_setflags( context, auth_context, flags );
472 if (asprintf(&host_princ_s, "%s$", global_myname()) == -1) {
476 strlower_m(host_princ_s);
477 ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
479 DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
480 host_princ_s, error_message(ret)));
485 if ( use_replay_cache ) {
487 /* Lock a mutex surrounding the replay as there is no
488 locking in the MIT krb5 code surrounding the replay
491 mutex = grab_named_mutex(talloc_tos(), "replay cache mutex",
494 DEBUG(1,("ads_verify_ticket: unable to protect "
495 "replay cache with mutex.\n"));
500 /* JRA. We must set the rcache here. This will prevent
503 ret = krb5_get_server_rcache(context,
504 krb5_princ_component(context, host_princ, 0),
507 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
508 "failed (%s)\n", error_message(ret)));
512 ret = krb5_auth_con_setrcache(context, auth_context, rcache);
514 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
515 "failed (%s)\n", error_message(ret)));
520 switch (lp_kerberos_method()) {
522 case KERBEROS_VERIFY_SECRETS:
523 auth_ok = ads_secrets_verify_ticket(context, auth_context,
524 host_princ, ticket, &tkt, &keyblock, &ret);
526 case KERBEROS_VERIFY_SYSTEM_KEYTAB:
527 auth_ok = ads_keytab_verify_ticket(context, auth_context,
528 ticket, &tkt, &keyblock, &ret);
530 case KERBEROS_VERIFY_DEDICATED_KEYTAB:
531 auth_ok = ads_dedicated_keytab_verify_ticket(context,
532 auth_context, ticket, &tkt, &keyblock, &ret);
534 case KERBEROS_VERIFY_SECRETS_AND_KEYTAB:
535 /* First try secrets.tdb and fallback to the krb5.keytab if
536 necessary. This is the pre 3.4 behavior when
537 "use kerberos keytab" was true.*/
538 auth_ok = ads_secrets_verify_ticket(context, auth_context,
539 host_princ, ticket, &tkt, &keyblock, &ret);
542 /* Only fallback if we failed to decrypt the ticket */
543 if (ret != KRB5KRB_AP_ERR_TKT_NYV &&
544 ret != KRB5KRB_AP_ERR_TKT_EXPIRED &&
545 ret != KRB5KRB_AP_ERR_SKEW) {
546 auth_ok = ads_keytab_verify_ticket(context,
547 auth_context, ticket, &tkt, &keyblock,
554 if ( use_replay_cache ) {
557 /* Heimdal leaks here, if we fix the leak, MIT crashes */
559 krb5_rc_close(context, rcache);
565 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
566 error_message(ret)));
567 /* Try map the error return in case it's something like
568 * a clock skew error.
570 sret = krb5_to_nt_status(ret);
571 if (NT_STATUS_IS_OK(sret) || NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
572 sret = NT_STATUS_LOGON_FAILURE;
574 DEBUG(10,("ads_verify_ticket: returning error %s\n",
579 authtime = get_authtime_from_tkt(tkt);
580 client_principal = get_principal_from_tkt(tkt);
582 ret = krb5_mk_rep(context, auth_context, &packet);
584 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
585 error_message(ret)));
589 *ap_rep = data_blob(packet.data, packet.length);
591 kerberos_free_data_contents(context, &packet);
595 get_krb5_smb_session_key(context, auth_context, session_key, True);
596 dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
599 file_save("/tmp/ticket.dat", ticket->data, ticket->length);
602 /* continue when no PAC is retrieved or we couldn't decode the PAC
603 (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
604 Kerberos tickets encrypted using a DES key) - Guenther */
606 got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
607 if (!got_auth_data) {
608 DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
612 pac_ret = decode_pac_data(mem_ctx, &auth_data, context, keyblock, client_principal, authtime, pac_data);
613 if (!NT_STATUS_IS_OK(pac_ret)) {
614 DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret)));
617 data_blob_free(&auth_data);
621 #if defined(HAVE_KRB5_TKT_ENC_PART2)
623 if (tkt->enc_part2) {
624 file_save("/tmp/authdata.dat",
625 tkt->enc_part2->authorization_data[0]->contents,
626 tkt->enc_part2->authorization_data[0]->length);
630 if (tkt->ticket.authorization_data) {
631 file_save("/tmp/authdata.dat",
632 tkt->ticket.authorization_data->val->ad_data.data,
633 tkt->ticket.authorization_data->val->ad_data.length);
638 if ((ret = smb_krb5_unparse_name(context, client_principal, principal))) {
639 DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
640 error_message(ret)));
641 sret = NT_STATUS_LOGON_FAILURE;
651 if (!NT_STATUS_IS_OK(sret)) {
652 data_blob_free(&auth_data);
655 if (!NT_STATUS_IS_OK(sret)) {
656 data_blob_free(ap_rep);
660 krb5_free_principal(context, host_princ);
664 krb5_free_keyblock(context, keyblock);
668 krb5_free_ticket(context, tkt);
671 SAFE_FREE(host_princ_s);
674 krb5_auth_con_free(context, auth_context);
678 krb5_free_context(context);
684 #endif /* HAVE_KRB5 */