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 /**********************************************************************************
35 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
36 it's more like what microsoft does... see comment in utils/net_ads.c in the
37 ads_keytab_add_entry function for details.
38 ***********************************************************************************/
40 static BOOL ads_keytab_verify_ticket(krb5_context context,
41 krb5_auth_context auth_context,
42 const DATA_BLOB *ticket,
44 krb5_keyblock **keyblock,
45 krb5_error_code *perr)
47 krb5_error_code ret = 0;
49 krb5_keytab keytab = NULL;
50 krb5_kt_cursor kt_cursor;
51 krb5_keytab_entry kt_entry;
52 char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
53 char *entry_princ_s = NULL;
54 fstring my_name, my_fqdn;
56 int number_matched_principals = 0;
63 /* Generate the list of principal names which we expect
64 * clients might want to use for authenticating to the file
65 * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
67 fstrcpy(my_name, global_myname());
70 name_to_fqdn(my_fqdn, global_myname());
72 asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm());
73 asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm());
74 asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm());
75 asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
76 asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm());
77 asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm());
78 asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
80 ZERO_STRUCT(kt_entry);
81 ZERO_STRUCT(kt_cursor);
83 ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
85 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
89 /* Iterate through the keytab. For each key, if the principal
90 * name case-insensitively matches one of the allowed formats,
91 * try verifying the ticket using that principal. */
93 ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
95 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
99 while (!auth_ok && (krb5_kt_next_entry(context, keytab, &kt_entry, &kt_cursor) == 0)) {
100 ret = smb_krb5_unparse_name(context, kt_entry.principal, &entry_princ_s);
102 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
103 error_message(ret)));
107 for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
109 if (!strequal(entry_princ_s, valid_princ_formats[i])) {
113 number_matched_principals++;
114 packet.length = ticket->length;
115 packet.data = (char *)ticket->data;
118 ret = krb5_rd_req_return_keyblock_from_keytab(context, &auth_context, &packet,
119 kt_entry.principal, keytab,
120 NULL, pp_tkt, keyblock);
123 DEBUG(10,("ads_keytab_verify_ticket: "
124 "krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
125 entry_princ_s, error_message(ret)));
127 /* workaround for MIT:
128 * as krb5_ktfile_get_entry will explicitly
129 * close the krb5_keytab as soon as krb5_rd_req
130 * has sucessfully decrypted the ticket but the
131 * ticket is not valid yet (due to clockskew)
132 * there is no point in querying more keytab
133 * entries - Guenther */
135 if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
136 ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
137 ret == KRB5KRB_AP_ERR_SKEW) {
141 DEBUG(3,("ads_keytab_verify_ticket: "
142 "krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
149 /* Free the name we parsed. */
150 SAFE_FREE(entry_princ_s);
152 /* Free the entry we just read. */
153 smb_krb5_kt_free_entry(context, &kt_entry);
154 ZERO_STRUCT(kt_entry);
156 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
158 ZERO_STRUCT(kt_cursor);
162 for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
163 SAFE_FREE(valid_princ_formats[i]);
167 if (!number_matched_principals) {
168 DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
170 DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
171 number_matched_principals));
175 SAFE_FREE(entry_princ_s);
178 krb5_keytab_entry zero_kt_entry;
179 ZERO_STRUCT(zero_kt_entry);
180 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
181 smb_krb5_kt_free_entry(context, &kt_entry);
186 krb5_kt_cursor zero_csr;
187 ZERO_STRUCT(zero_csr);
188 if ((memcmp(&kt_cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
189 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
194 krb5_kt_close(context, keytab);
200 /**********************************************************************************
201 Try to verify a ticket using the secrets.tdb.
202 ***********************************************************************************/
204 static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
205 krb5_auth_context auth_context,
206 krb5_principal host_princ,
207 const DATA_BLOB *ticket,
208 krb5_ticket **pp_tkt,
209 krb5_keyblock **keyblock,
210 krb5_error_code *perr)
212 krb5_error_code ret = 0;
213 BOOL auth_ok = False;
214 char *password_s = NULL;
216 krb5_enctype enctypes[] = {
217 #if defined(ENCTYPE_ARCFOUR_HMAC)
218 ENCTYPE_ARCFOUR_HMAC,
232 if (!secrets_init()) {
233 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
234 *perr = KRB5_CONFIG_CANTOPEN;
238 password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
240 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
241 *perr = KRB5_LIBOS_CANTREADPWD;
245 password.data = password_s;
246 password.length = strlen(password_s);
248 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
250 packet.length = ticket->length;
251 packet.data = (char *)ticket->data;
253 /* We need to setup a auth context with each possible encoding type in turn. */
254 for (i=0;enctypes[i];i++) {
255 krb5_keyblock *key = NULL;
257 if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
262 if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
267 krb5_auth_con_setuseruserkey(context, auth_context, key);
269 if (!(ret = krb5_rd_req(context, &auth_context, &packet,
271 NULL, NULL, pp_tkt))) {
272 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
273 (unsigned int)enctypes[i] ));
275 krb5_copy_keyblock(context, key, keyblock);
276 krb5_free_keyblock(context, key);
281 DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
282 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
283 (unsigned int)enctypes[i], error_message(ret)));
285 /* successfully decrypted but ticket is just not valid at the moment */
286 if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
287 ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
288 ret == KRB5KRB_AP_ERR_SKEW) {
293 krb5_free_keyblock(context, key);
299 SAFE_FREE(password_s);
304 /**********************************************************************************
305 Verify an incoming ticket and parse out the principal name and
306 authorization_data if available.
307 ***********************************************************************************/
309 NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
312 const DATA_BLOB *ticket,
316 DATA_BLOB *session_key,
317 BOOL use_replay_cache)
319 NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
322 krb5_context context = NULL;
323 krb5_auth_context auth_context = NULL;
325 krb5_ticket *tkt = NULL;
326 krb5_rcache rcache = NULL;
327 krb5_keyblock *keyblock = NULL;
329 krb5_error_code ret = 0;
331 krb5_principal host_princ = NULL;
332 krb5_const_principal client_principal = NULL;
333 char *host_princ_s = NULL;
334 BOOL auth_ok = False;
335 BOOL got_replay_mutex = False;
336 BOOL got_auth_data = False;
339 ZERO_STRUCT(auth_data);
343 *ap_rep = data_blob_null;
344 *session_key = data_blob_null;
346 initialize_krb5_error_table();
347 ret = krb5_init_context(&context);
349 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
350 return NT_STATUS_LOGON_FAILURE;
353 if (time_offset != 0) {
354 krb5_set_real_time(context, time(NULL) + time_offset, 0);
357 ret = krb5_set_default_realm(context, realm);
359 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
363 /* This whole process is far more complex than I would
364 like. We have to go through all this to allow us to store
365 the secret internally, instead of using /etc/krb5.keytab */
367 ret = krb5_auth_con_init(context, &auth_context);
369 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
373 krb5_auth_con_getflags( context, auth_context, &flags );
374 if ( !use_replay_cache ) {
375 /* Disable default use of a replay cache */
376 flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
377 krb5_auth_con_setflags( context, auth_context, flags );
380 asprintf(&host_princ_s, "%s$", global_myname());
385 strlower_m(host_princ_s);
386 ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
388 DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
389 host_princ_s, error_message(ret)));
394 if ( use_replay_cache ) {
396 /* Lock a mutex surrounding the replay as there is no
397 locking in the MIT krb5 code surrounding the replay
400 if (!grab_server_mutex("replay cache mutex")) {
401 DEBUG(1,("ads_verify_ticket: unable to protect "
402 "replay cache with mutex.\n"));
407 got_replay_mutex = True;
409 /* JRA. We must set the rcache here. This will prevent
412 ret = krb5_get_server_rcache(context,
413 krb5_princ_component(context, host_princ, 0),
416 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
417 "failed (%s)\n", error_message(ret)));
421 ret = krb5_auth_con_setrcache(context, auth_context, rcache);
423 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
424 "failed (%s)\n", error_message(ret)));
429 /* Try secrets.tdb first and fallback to the krb5.keytab if
432 auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
433 ticket, &tkt, &keyblock, &ret);
435 if (!auth_ok && lp_use_kerberos_keytab()) {
436 auth_ok = ads_keytab_verify_ticket(context, auth_context,
437 ticket, &tkt, &keyblock, &ret);
440 if ( use_replay_cache ) {
441 release_server_mutex();
442 got_replay_mutex = False;
444 /* Heimdal leaks here, if we fix the leak, MIT crashes */
446 krb5_rc_close(context, rcache);
452 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
453 error_message(ret)));
454 /* Try map the error return in case it's something like
455 * a clock skew error.
457 sret = krb5_to_nt_status(ret);
458 if (NT_STATUS_IS_OK(sret) || NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
459 sret = NT_STATUS_LOGON_FAILURE;
461 DEBUG(10,("ads_verify_ticket: returning error %s\n",
466 authtime = get_authtime_from_tkt(tkt);
467 client_principal = get_principal_from_tkt(tkt);
469 ret = krb5_mk_rep(context, auth_context, &packet);
471 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
472 error_message(ret)));
476 *ap_rep = data_blob(packet.data, packet.length);
478 kerberos_free_data_contents(context, &packet);
482 get_krb5_smb_session_key(context, auth_context, session_key, True);
483 dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
486 file_save("/tmp/ticket.dat", ticket->data, ticket->length);
489 /* continue when no PAC is retrieved or we couldn't decode the PAC
490 (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
491 Kerberos tickets encrypted using a DES key) - Guenther */
493 got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
494 if (!got_auth_data) {
495 DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
498 if (got_auth_data && pac_data != NULL) {
500 pac_ret = decode_pac_data(mem_ctx, &auth_data, context, keyblock, client_principal, authtime, pac_data);
501 if (!NT_STATUS_IS_OK(pac_ret)) {
502 DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret)));
505 data_blob_free(&auth_data);
509 #if defined(HAVE_KRB5_TKT_ENC_PART2)
511 if (tkt->enc_part2) {
512 file_save("/tmp/authdata.dat",
513 tkt->enc_part2->authorization_data[0]->contents,
514 tkt->enc_part2->authorization_data[0]->length);
518 if (tkt->ticket.authorization_data) {
519 file_save("/tmp/authdata.dat",
520 tkt->ticket.authorization_data->val->ad_data.data,
521 tkt->ticket.authorization_data->val->ad_data.length);
526 if ((ret = smb_krb5_unparse_name(context, client_principal, principal))) {
527 DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
528 error_message(ret)));
529 sret = NT_STATUS_LOGON_FAILURE;
537 if (got_replay_mutex) {
538 release_server_mutex();
541 if (!NT_STATUS_IS_OK(sret)) {
542 data_blob_free(&auth_data);
545 if (!NT_STATUS_IS_OK(sret)) {
546 data_blob_free(ap_rep);
550 krb5_free_principal(context, host_princ);
554 krb5_free_keyblock(context, keyblock);
558 krb5_free_ticket(context, tkt);
561 SAFE_FREE(host_princ_s);
564 krb5_auth_con_free(context, auth_context);
568 krb5_free_context(context);
574 #endif /* HAVE_KRB5 */