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
;
55 ZERO_STRUCT(kt_entry
);
57 ret
= smb_krb5_open_keytab(context
, lp_dedicated_keytab_file(), true,
60 DEBUG(1, ("smb_krb5_open_keytab failed (%s)\n",
65 packet
.length
= ticket
->length
;
66 packet
.data
= (char *)ticket
->data
;
68 ret
= krb5_rd_req(context
, &auth_context
, &packet
, NULL
, keytab
,
71 DEBUG(0, ("krb5_rd_req failed (%s)\n", error_message(ret
)));
75 #ifdef HAVE_ETYPE_IN_ENCRYPTEDDATA /* Heimdal */
76 enctype
= dec_ticket
->ticket
.key
.keytype
;
78 enctype
= dec_ticket
->enc_part
.enctype
;
79 kvno
= dec_ticket
->enc_part
.kvno
;
82 /* Get the key for checking the pac signature */
83 ret
= krb5_kt_get_entry(context
, keytab
, dec_ticket
->server
,
84 kvno
, enctype
, &kt_entry
);
86 DEBUG(0, ("krb5_kt_get_entry failed (%s)\n",
91 ret
= krb5_copy_keyblock(context
, KRB5_KT_KEY(&kt_entry
), keyblock
);
92 smb_krb5_kt_free_entry(context
, &kt_entry
);
95 DEBUG(0, ("failed to copy key: %s\n",
101 *pp_tkt
= dec_ticket
;
106 krb5_free_ticket(context
, dec_ticket
);
109 krb5_kt_close(context
, keytab
);
115 /**********************************************************************************
116 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
117 it's more like what microsoft does... see comment in utils/net_ads.c in the
118 ads_keytab_add_entry function for details.
119 ***********************************************************************************/
121 static bool ads_keytab_verify_ticket(krb5_context context
,
122 krb5_auth_context auth_context
,
123 const DATA_BLOB
*ticket
,
124 krb5_ticket
**pp_tkt
,
125 krb5_keyblock
**keyblock
,
126 krb5_error_code
*perr
)
128 krb5_error_code ret
= 0;
129 bool auth_ok
= False
;
130 krb5_keytab keytab
= NULL
;
131 krb5_kt_cursor kt_cursor
;
132 krb5_keytab_entry kt_entry
;
133 char *valid_princ_formats
[7] = { NULL
, NULL
, NULL
, NULL
, NULL
, NULL
, NULL
};
134 char *entry_princ_s
= NULL
;
135 fstring my_name
, my_fqdn
;
137 int number_matched_principals
= 0;
144 /* Generate the list of principal names which we expect
145 * clients might want to use for authenticating to the file
146 * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
148 fstrcpy(my_name
, global_myname());
151 name_to_fqdn(my_fqdn
, global_myname());
153 if (asprintf(&valid_princ_formats
[0], "%s$@%s", my_name
, lp_realm()) == -1) {
156 if (asprintf(&valid_princ_formats
[1], "host/%s@%s", my_name
, lp_realm()) == -1) {
159 if (asprintf(&valid_princ_formats
[2], "host/%s@%s", my_fqdn
, lp_realm()) == -1) {
162 if (asprintf(&valid_princ_formats
[3], "host/%s.%s@%s", my_name
, lp_realm(), lp_realm()) == -1) {
165 if (asprintf(&valid_princ_formats
[4], "cifs/%s@%s", my_name
, lp_realm()) == -1) {
168 if (asprintf(&valid_princ_formats
[5], "cifs/%s@%s", my_fqdn
, lp_realm()) == -1) {
171 if (asprintf(&valid_princ_formats
[6], "cifs/%s.%s@%s", my_name
, lp_realm(), lp_realm()) == -1) {
175 ZERO_STRUCT(kt_entry
);
176 ZERO_STRUCT(kt_cursor
);
178 ret
= smb_krb5_open_keytab(context
, NULL
, False
, &keytab
);
180 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret
)));
184 /* Iterate through the keytab. For each key, if the principal
185 * name case-insensitively matches one of the allowed formats,
186 * try verifying the ticket using that principal. */
188 ret
= krb5_kt_start_seq_get(context
, keytab
, &kt_cursor
);
190 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret
)));
194 while (!auth_ok
&& (krb5_kt_next_entry(context
, keytab
, &kt_entry
, &kt_cursor
) == 0)) {
195 ret
= smb_krb5_unparse_name(talloc_tos(), context
, kt_entry
.principal
, &entry_princ_s
);
197 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
198 error_message(ret
)));
202 for (i
= 0; i
< ARRAY_SIZE(valid_princ_formats
); i
++) {
204 if (!strequal(entry_princ_s
, valid_princ_formats
[i
])) {
208 number_matched_principals
++;
209 packet
.length
= ticket
->length
;
210 packet
.data
= (char *)ticket
->data
;
213 ret
= krb5_rd_req_return_keyblock_from_keytab(context
, &auth_context
, &packet
,
214 kt_entry
.principal
, keytab
,
215 NULL
, pp_tkt
, keyblock
);
218 DEBUG(10,("ads_keytab_verify_ticket: "
219 "krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
220 entry_princ_s
, error_message(ret
)));
222 /* workaround for MIT:
223 * as krb5_ktfile_get_entry will explicitly
224 * close the krb5_keytab as soon as krb5_rd_req
225 * has successfully decrypted the ticket but the
226 * ticket is not valid yet (due to clockskew)
227 * there is no point in querying more keytab
228 * entries - Guenther */
230 if (ret
== KRB5KRB_AP_ERR_TKT_NYV
||
231 ret
== KRB5KRB_AP_ERR_TKT_EXPIRED
||
232 ret
== KRB5KRB_AP_ERR_SKEW
) {
236 DEBUG(3,("ads_keytab_verify_ticket: "
237 "krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
244 /* Free the name we parsed. */
245 TALLOC_FREE(entry_princ_s
);
247 /* Free the entry we just read. */
248 smb_krb5_kt_free_entry(context
, &kt_entry
);
249 ZERO_STRUCT(kt_entry
);
251 krb5_kt_end_seq_get(context
, keytab
, &kt_cursor
);
253 ZERO_STRUCT(kt_cursor
);
257 for (i
= 0; i
< ARRAY_SIZE(valid_princ_formats
); i
++) {
258 SAFE_FREE(valid_princ_formats
[i
]);
262 if (!number_matched_principals
) {
263 DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
265 DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
266 number_matched_principals
));
270 SAFE_FREE(entry_princ_s
);
273 krb5_keytab_entry zero_kt_entry
;
274 ZERO_STRUCT(zero_kt_entry
);
275 if (memcmp(&zero_kt_entry
, &kt_entry
, sizeof(krb5_keytab_entry
))) {
276 smb_krb5_kt_free_entry(context
, &kt_entry
);
281 krb5_kt_cursor zero_csr
;
282 ZERO_STRUCT(zero_csr
);
283 if ((memcmp(&kt_cursor
, &zero_csr
, sizeof(krb5_kt_cursor
)) != 0) && keytab
) {
284 krb5_kt_end_seq_get(context
, keytab
, &kt_cursor
);
289 krb5_kt_close(context
, keytab
);
295 /**********************************************************************************
296 Try to verify a ticket using the secrets.tdb.
297 ***********************************************************************************/
299 static krb5_error_code
ads_secrets_verify_ticket(krb5_context context
,
300 krb5_auth_context auth_context
,
301 krb5_principal host_princ
,
302 const DATA_BLOB
*ticket
,
303 krb5_ticket
**pp_tkt
,
304 krb5_keyblock
**keyblock
,
305 krb5_error_code
*perr
)
307 krb5_error_code ret
= 0;
308 bool auth_ok
= False
;
309 char *password_s
= NULL
;
311 krb5_enctype enctypes
[] = {
312 #if defined(ENCTYPE_ARCFOUR_HMAC)
313 ENCTYPE_ARCFOUR_HMAC
,
327 if (!secrets_init()) {
328 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
329 *perr
= KRB5_CONFIG_CANTOPEN
;
333 password_s
= secrets_fetch_machine_password(lp_workgroup(), NULL
, NULL
);
335 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
336 *perr
= KRB5_LIBOS_CANTREADPWD
;
340 password
.data
= password_s
;
341 password
.length
= strlen(password_s
);
343 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
345 packet
.length
= ticket
->length
;
346 packet
.data
= (char *)ticket
->data
;
348 /* We need to setup a auth context with each possible encoding type in turn. */
349 for (i
=0;enctypes
[i
];i
++) {
350 krb5_keyblock
*key
= NULL
;
352 if (!(key
= SMB_MALLOC_P(krb5_keyblock
))) {
357 if (create_kerberos_key_from_string(context
, host_princ
, &password
, key
, enctypes
[i
], false)) {
362 krb5_auth_con_setuseruserkey(context
, auth_context
, key
);
364 if (!(ret
= krb5_rd_req(context
, &auth_context
, &packet
,
366 NULL
, NULL
, pp_tkt
))) {
367 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
368 (unsigned int)enctypes
[i
] ));
370 krb5_copy_keyblock(context
, key
, keyblock
);
371 krb5_free_keyblock(context
, key
);
375 DEBUG((ret
!= KRB5_BAD_ENCTYPE
) ? 3 : 10,
376 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
377 (unsigned int)enctypes
[i
], error_message(ret
)));
379 /* successfully decrypted but ticket is just not valid at the moment */
380 if (ret
== KRB5KRB_AP_ERR_TKT_NYV
||
381 ret
== KRB5KRB_AP_ERR_TKT_EXPIRED
||
382 ret
== KRB5KRB_AP_ERR_SKEW
) {
383 krb5_free_keyblock(context
, key
);
387 krb5_free_keyblock(context
, key
);
392 SAFE_FREE(password_s
);
397 /**********************************************************************************
398 Verify an incoming ticket and parse out the principal name and
399 authorization_data if available.
400 ***********************************************************************************/
402 NTSTATUS
ads_verify_ticket(TALLOC_CTX
*mem_ctx
,
405 const DATA_BLOB
*ticket
,
407 struct PAC_DATA
**pac_data
,
409 DATA_BLOB
*session_key
,
410 bool use_replay_cache
)
412 NTSTATUS sret
= NT_STATUS_LOGON_FAILURE
;
415 krb5_context context
= NULL
;
416 krb5_auth_context auth_context
= NULL
;
418 krb5_ticket
*tkt
= NULL
;
419 krb5_rcache rcache
= NULL
;
420 krb5_keyblock
*keyblock
= NULL
;
422 krb5_error_code ret
= 0;
424 krb5_principal host_princ
= NULL
;
425 krb5_const_principal client_principal
= NULL
;
426 char *host_princ_s
= NULL
;
427 bool auth_ok
= False
;
428 bool got_auth_data
= False
;
429 struct named_mutex
*mutex
= NULL
;
432 ZERO_STRUCT(auth_data
);
436 *ap_rep
= data_blob_null
;
437 *session_key
= data_blob_null
;
439 initialize_krb5_error_table();
440 ret
= krb5_init_context(&context
);
442 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret
)));
443 return NT_STATUS_LOGON_FAILURE
;
446 if (time_offset
!= 0) {
447 krb5_set_real_time(context
, time(NULL
) + time_offset
, 0);
450 ret
= krb5_set_default_realm(context
, realm
);
452 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret
)));
456 /* This whole process is far more complex than I would
457 like. We have to go through all this to allow us to store
458 the secret internally, instead of using /etc/krb5.keytab */
460 ret
= krb5_auth_con_init(context
, &auth_context
);
462 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret
)));
466 krb5_auth_con_getflags( context
, auth_context
, &flags
);
467 if ( !use_replay_cache
) {
468 /* Disable default use of a replay cache */
469 flags
&= ~KRB5_AUTH_CONTEXT_DO_TIME
;
470 krb5_auth_con_setflags( context
, auth_context
, flags
);
473 if (asprintf(&host_princ_s
, "%s$", global_myname()) == -1) {
477 strlower_m(host_princ_s
);
478 ret
= smb_krb5_parse_name(context
, host_princ_s
, &host_princ
);
480 DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
481 host_princ_s
, error_message(ret
)));
486 if ( use_replay_cache
) {
488 /* Lock a mutex surrounding the replay as there is no
489 locking in the MIT krb5 code surrounding the replay
492 mutex
= grab_named_mutex(talloc_tos(), "replay cache mutex",
495 DEBUG(1,("ads_verify_ticket: unable to protect "
496 "replay cache with mutex.\n"));
501 /* JRA. We must set the rcache here. This will prevent
504 ret
= krb5_get_server_rcache(context
,
505 krb5_princ_component(context
, host_princ
, 0),
508 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
509 "failed (%s)\n", error_message(ret
)));
513 ret
= krb5_auth_con_setrcache(context
, auth_context
, rcache
);
515 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
516 "failed (%s)\n", error_message(ret
)));
521 switch (lp_kerberos_method()) {
523 case KERBEROS_VERIFY_SECRETS
:
524 auth_ok
= ads_secrets_verify_ticket(context
, auth_context
,
525 host_princ
, ticket
, &tkt
, &keyblock
, &ret
);
527 case KERBEROS_VERIFY_SYSTEM_KEYTAB
:
528 auth_ok
= ads_keytab_verify_ticket(context
, auth_context
,
529 ticket
, &tkt
, &keyblock
, &ret
);
531 case KERBEROS_VERIFY_DEDICATED_KEYTAB
:
532 auth_ok
= ads_dedicated_keytab_verify_ticket(context
,
533 auth_context
, ticket
, &tkt
, &keyblock
, &ret
);
535 case KERBEROS_VERIFY_SECRETS_AND_KEYTAB
:
536 /* First try secrets.tdb and fallback to the krb5.keytab if
537 necessary. This is the pre 3.4 behavior when
538 "use kerberos keytab" was true.*/
539 auth_ok
= ads_secrets_verify_ticket(context
, auth_context
,
540 host_princ
, ticket
, &tkt
, &keyblock
, &ret
);
543 /* Only fallback if we failed to decrypt the ticket */
544 if (ret
!= KRB5KRB_AP_ERR_TKT_NYV
&&
545 ret
!= KRB5KRB_AP_ERR_TKT_EXPIRED
&&
546 ret
!= KRB5KRB_AP_ERR_SKEW
) {
547 auth_ok
= ads_keytab_verify_ticket(context
,
548 auth_context
, ticket
, &tkt
, &keyblock
,
555 if ( use_replay_cache
) {
558 /* Heimdal leaks here, if we fix the leak, MIT crashes */
560 krb5_rc_close(context
, rcache
);
566 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
567 error_message(ret
)));
568 /* Try map the error return in case it's something like
569 * a clock skew error.
571 sret
= krb5_to_nt_status(ret
);
572 if (NT_STATUS_IS_OK(sret
) || NT_STATUS_EQUAL(sret
,NT_STATUS_UNSUCCESSFUL
)) {
573 sret
= NT_STATUS_LOGON_FAILURE
;
575 DEBUG(10,("ads_verify_ticket: returning error %s\n",
580 authtime
= get_authtime_from_tkt(tkt
);
581 client_principal
= get_principal_from_tkt(tkt
);
583 ret
= krb5_mk_rep(context
, auth_context
, &packet
);
585 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
586 error_message(ret
)));
590 *ap_rep
= data_blob(packet
.data
, packet
.length
);
592 kerberos_free_data_contents(context
, &packet
);
596 get_krb5_smb_session_key(context
, auth_context
, session_key
, True
);
597 dump_data_pw("SMB session key (from ticket)\n", session_key
->data
, session_key
->length
);
600 file_save("/tmp/ticket.dat", ticket
->data
, ticket
->length
);
603 /* continue when no PAC is retrieved or we couldn't decode the PAC
604 (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
605 Kerberos tickets encrypted using a DES key) - Guenther */
607 got_auth_data
= get_auth_data_from_tkt(mem_ctx
, &auth_data
, tkt
);
608 if (!got_auth_data
) {
609 DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
613 pac_ret
= decode_pac_data(mem_ctx
, &auth_data
, context
, keyblock
, client_principal
, authtime
, pac_data
);
614 if (!NT_STATUS_IS_OK(pac_ret
)) {
615 DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret
)));
618 data_blob_free(&auth_data
);
622 #if defined(HAVE_KRB5_TKT_ENC_PART2)
624 if (tkt
->enc_part2
) {
625 file_save("/tmp/authdata.dat",
626 tkt
->enc_part2
->authorization_data
[0]->contents
,
627 tkt
->enc_part2
->authorization_data
[0]->length
);
631 if (tkt
->ticket
.authorization_data
) {
632 file_save("/tmp/authdata.dat",
633 tkt
->ticket
.authorization_data
->val
->ad_data
.data
,
634 tkt
->ticket
.authorization_data
->val
->ad_data
.length
);
639 if ((ret
= smb_krb5_unparse_name(mem_ctx
, context
, client_principal
, principal
))) {
640 DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
641 error_message(ret
)));
642 sret
= NT_STATUS_LOGON_FAILURE
;
652 if (!NT_STATUS_IS_OK(sret
)) {
653 data_blob_free(&auth_data
);
656 if (!NT_STATUS_IS_OK(sret
)) {
657 data_blob_free(ap_rep
);
661 krb5_free_principal(context
, host_princ
);
665 krb5_free_keyblock(context
, keyblock
);
669 krb5_free_ticket(context
, tkt
);
672 SAFE_FREE(host_princ_s
);
675 krb5_auth_con_free(context
, auth_context
);
679 krb5_free_context(context
);
685 #endif /* HAVE_KRB5 */