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 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK /* Heimdal */
92 ret
= krb5_copy_keyblock(context
, &kt_entry
.keyblock
, keyblock
);
93 #elif defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) /* MIT */
94 ret
= krb5_copy_keyblock(context
, &kt_entry
.key
, keyblock
);
96 #error UNKNOWN_KRB5_KEYTAB_ENTRY_FORMAT
98 smb_krb5_kt_free_entry(context
, &kt_entry
);
101 DEBUG(0, ("failed to copy key: %s\n",
102 error_message(ret
)));
107 *pp_tkt
= dec_ticket
;
112 krb5_free_ticket(context
, dec_ticket
);
115 krb5_kt_close(context
, keytab
);
121 /**********************************************************************************
122 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
123 it's more like what microsoft does... see comment in utils/net_ads.c in the
124 ads_keytab_add_entry function for details.
125 ***********************************************************************************/
127 static bool ads_keytab_verify_ticket(krb5_context context
,
128 krb5_auth_context auth_context
,
129 const DATA_BLOB
*ticket
,
130 krb5_ticket
**pp_tkt
,
131 krb5_keyblock
**keyblock
,
132 krb5_error_code
*perr
)
134 krb5_error_code ret
= 0;
135 bool auth_ok
= False
;
136 krb5_keytab keytab
= NULL
;
137 krb5_kt_cursor kt_cursor
;
138 krb5_keytab_entry kt_entry
;
139 char *valid_princ_formats
[7] = { NULL
, NULL
, NULL
, NULL
, NULL
, NULL
, NULL
};
140 char *entry_princ_s
= NULL
;
141 fstring my_name
, my_fqdn
;
143 int number_matched_principals
= 0;
150 /* Generate the list of principal names which we expect
151 * clients might want to use for authenticating to the file
152 * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
154 fstrcpy(my_name
, global_myname());
157 name_to_fqdn(my_fqdn
, global_myname());
159 if (asprintf(&valid_princ_formats
[0], "%s$@%s", my_name
, lp_realm()) == -1) {
162 if (asprintf(&valid_princ_formats
[1], "host/%s@%s", my_name
, lp_realm()) == -1) {
165 if (asprintf(&valid_princ_formats
[2], "host/%s@%s", my_fqdn
, lp_realm()) == -1) {
168 if (asprintf(&valid_princ_formats
[3], "host/%s.%s@%s", my_name
, lp_realm(), lp_realm()) == -1) {
171 if (asprintf(&valid_princ_formats
[4], "cifs/%s@%s", my_name
, lp_realm()) == -1) {
174 if (asprintf(&valid_princ_formats
[5], "cifs/%s@%s", my_fqdn
, lp_realm()) == -1) {
177 if (asprintf(&valid_princ_formats
[6], "cifs/%s.%s@%s", my_name
, lp_realm(), lp_realm()) == -1) {
181 ZERO_STRUCT(kt_entry
);
182 ZERO_STRUCT(kt_cursor
);
184 ret
= smb_krb5_open_keytab(context
, NULL
, False
, &keytab
);
186 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret
)));
190 /* Iterate through the keytab. For each key, if the principal
191 * name case-insensitively matches one of the allowed formats,
192 * try verifying the ticket using that principal. */
194 ret
= krb5_kt_start_seq_get(context
, keytab
, &kt_cursor
);
196 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret
)));
200 while (!auth_ok
&& (krb5_kt_next_entry(context
, keytab
, &kt_entry
, &kt_cursor
) == 0)) {
201 ret
= smb_krb5_unparse_name(context
, kt_entry
.principal
, &entry_princ_s
);
203 DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
204 error_message(ret
)));
208 for (i
= 0; i
< ARRAY_SIZE(valid_princ_formats
); i
++) {
210 if (!strequal(entry_princ_s
, valid_princ_formats
[i
])) {
214 number_matched_principals
++;
215 packet
.length
= ticket
->length
;
216 packet
.data
= (char *)ticket
->data
;
219 ret
= krb5_rd_req_return_keyblock_from_keytab(context
, &auth_context
, &packet
,
220 kt_entry
.principal
, keytab
,
221 NULL
, pp_tkt
, keyblock
);
224 DEBUG(10,("ads_keytab_verify_ticket: "
225 "krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
226 entry_princ_s
, error_message(ret
)));
228 /* workaround for MIT:
229 * as krb5_ktfile_get_entry will explicitly
230 * close the krb5_keytab as soon as krb5_rd_req
231 * has successfully decrypted the ticket but the
232 * ticket is not valid yet (due to clockskew)
233 * there is no point in querying more keytab
234 * entries - Guenther */
236 if (ret
== KRB5KRB_AP_ERR_TKT_NYV
||
237 ret
== KRB5KRB_AP_ERR_TKT_EXPIRED
||
238 ret
== KRB5KRB_AP_ERR_SKEW
) {
242 DEBUG(3,("ads_keytab_verify_ticket: "
243 "krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
250 /* Free the name we parsed. */
251 SAFE_FREE(entry_princ_s
);
253 /* Free the entry we just read. */
254 smb_krb5_kt_free_entry(context
, &kt_entry
);
255 ZERO_STRUCT(kt_entry
);
257 krb5_kt_end_seq_get(context
, keytab
, &kt_cursor
);
259 ZERO_STRUCT(kt_cursor
);
263 for (i
= 0; i
< ARRAY_SIZE(valid_princ_formats
); i
++) {
264 SAFE_FREE(valid_princ_formats
[i
]);
268 if (!number_matched_principals
) {
269 DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
271 DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
272 number_matched_principals
));
276 SAFE_FREE(entry_princ_s
);
279 krb5_keytab_entry zero_kt_entry
;
280 ZERO_STRUCT(zero_kt_entry
);
281 if (memcmp(&zero_kt_entry
, &kt_entry
, sizeof(krb5_keytab_entry
))) {
282 smb_krb5_kt_free_entry(context
, &kt_entry
);
287 krb5_kt_cursor zero_csr
;
288 ZERO_STRUCT(zero_csr
);
289 if ((memcmp(&kt_cursor
, &zero_csr
, sizeof(krb5_kt_cursor
)) != 0) && keytab
) {
290 krb5_kt_end_seq_get(context
, keytab
, &kt_cursor
);
295 krb5_kt_close(context
, keytab
);
301 /**********************************************************************************
302 Try to verify a ticket using the secrets.tdb.
303 ***********************************************************************************/
305 static krb5_error_code
ads_secrets_verify_ticket(krb5_context context
,
306 krb5_auth_context auth_context
,
307 krb5_principal host_princ
,
308 const DATA_BLOB
*ticket
,
309 krb5_ticket
**pp_tkt
,
310 krb5_keyblock
**keyblock
,
311 krb5_error_code
*perr
)
313 krb5_error_code ret
= 0;
314 bool auth_ok
= False
;
315 char *password_s
= NULL
;
317 krb5_enctype enctypes
[] = {
318 #if defined(ENCTYPE_ARCFOUR_HMAC)
319 ENCTYPE_ARCFOUR_HMAC
,
333 if (!secrets_init()) {
334 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
335 *perr
= KRB5_CONFIG_CANTOPEN
;
339 password_s
= secrets_fetch_machine_password(lp_workgroup(), NULL
, NULL
);
341 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
342 *perr
= KRB5_LIBOS_CANTREADPWD
;
346 password
.data
= password_s
;
347 password
.length
= strlen(password_s
);
349 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
351 packet
.length
= ticket
->length
;
352 packet
.data
= (char *)ticket
->data
;
354 /* We need to setup a auth context with each possible encoding type in turn. */
355 for (i
=0;enctypes
[i
];i
++) {
356 krb5_keyblock
*key
= NULL
;
358 if (!(key
= SMB_MALLOC_P(krb5_keyblock
))) {
363 if (create_kerberos_key_from_string(context
, host_princ
, &password
, key
, enctypes
[i
], false)) {
368 krb5_auth_con_setuseruserkey(context
, auth_context
, key
);
370 if (!(ret
= krb5_rd_req(context
, &auth_context
, &packet
,
372 NULL
, NULL
, pp_tkt
))) {
373 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
374 (unsigned int)enctypes
[i
] ));
376 krb5_copy_keyblock(context
, key
, keyblock
);
377 krb5_free_keyblock(context
, key
);
381 DEBUG((ret
!= KRB5_BAD_ENCTYPE
) ? 3 : 10,
382 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
383 (unsigned int)enctypes
[i
], error_message(ret
)));
385 /* successfully decrypted but ticket is just not valid at the moment */
386 if (ret
== KRB5KRB_AP_ERR_TKT_NYV
||
387 ret
== KRB5KRB_AP_ERR_TKT_EXPIRED
||
388 ret
== KRB5KRB_AP_ERR_SKEW
) {
389 krb5_free_keyblock(context
, key
);
393 krb5_free_keyblock(context
, key
);
398 SAFE_FREE(password_s
);
403 /**********************************************************************************
404 Verify an incoming ticket and parse out the principal name and
405 authorization_data if available.
406 ***********************************************************************************/
408 NTSTATUS
ads_verify_ticket(TALLOC_CTX
*mem_ctx
,
411 const DATA_BLOB
*ticket
,
413 struct PAC_DATA
**pac_data
,
415 DATA_BLOB
*session_key
,
416 bool use_replay_cache
)
418 NTSTATUS sret
= NT_STATUS_LOGON_FAILURE
;
421 krb5_context context
= NULL
;
422 krb5_auth_context auth_context
= NULL
;
424 krb5_ticket
*tkt
= NULL
;
425 krb5_rcache rcache
= NULL
;
426 krb5_keyblock
*keyblock
= NULL
;
428 krb5_error_code ret
= 0;
430 krb5_principal host_princ
= NULL
;
431 krb5_const_principal client_principal
= NULL
;
432 char *host_princ_s
= NULL
;
433 bool auth_ok
= False
;
434 bool got_auth_data
= False
;
435 struct named_mutex
*mutex
= NULL
;
438 ZERO_STRUCT(auth_data
);
442 *ap_rep
= data_blob_null
;
443 *session_key
= data_blob_null
;
445 initialize_krb5_error_table();
446 ret
= krb5_init_context(&context
);
448 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret
)));
449 return NT_STATUS_LOGON_FAILURE
;
452 if (time_offset
!= 0) {
453 krb5_set_real_time(context
, time(NULL
) + time_offset
, 0);
456 ret
= krb5_set_default_realm(context
, realm
);
458 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret
)));
462 /* This whole process is far more complex than I would
463 like. We have to go through all this to allow us to store
464 the secret internally, instead of using /etc/krb5.keytab */
466 ret
= krb5_auth_con_init(context
, &auth_context
);
468 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret
)));
472 krb5_auth_con_getflags( context
, auth_context
, &flags
);
473 if ( !use_replay_cache
) {
474 /* Disable default use of a replay cache */
475 flags
&= ~KRB5_AUTH_CONTEXT_DO_TIME
;
476 krb5_auth_con_setflags( context
, auth_context
, flags
);
479 if (asprintf(&host_princ_s
, "%s$", global_myname()) == -1) {
483 strlower_m(host_princ_s
);
484 ret
= smb_krb5_parse_name(context
, host_princ_s
, &host_princ
);
486 DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
487 host_princ_s
, error_message(ret
)));
492 if ( use_replay_cache
) {
494 /* Lock a mutex surrounding the replay as there is no
495 locking in the MIT krb5 code surrounding the replay
498 mutex
= grab_named_mutex(talloc_tos(), "replay cache mutex",
501 DEBUG(1,("ads_verify_ticket: unable to protect "
502 "replay cache with mutex.\n"));
507 /* JRA. We must set the rcache here. This will prevent
510 ret
= krb5_get_server_rcache(context
,
511 krb5_princ_component(context
, host_princ
, 0),
514 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
515 "failed (%s)\n", error_message(ret
)));
519 ret
= krb5_auth_con_setrcache(context
, auth_context
, rcache
);
521 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
522 "failed (%s)\n", error_message(ret
)));
527 switch (lp_kerberos_method()) {
529 case KERBEROS_VERIFY_SECRETS
:
530 auth_ok
= ads_secrets_verify_ticket(context
, auth_context
,
531 host_princ
, ticket
, &tkt
, &keyblock
, &ret
);
533 case KERBEROS_VERIFY_SYSTEM_KEYTAB
:
534 auth_ok
= ads_keytab_verify_ticket(context
, auth_context
,
535 ticket
, &tkt
, &keyblock
, &ret
);
537 case KERBEROS_VERIFY_DEDICATED_KEYTAB
:
538 auth_ok
= ads_dedicated_keytab_verify_ticket(context
,
539 auth_context
, ticket
, &tkt
, &keyblock
, &ret
);
541 case KERBEROS_VERIFY_SECRETS_AND_KEYTAB
:
542 /* First try secrets.tdb and fallback to the krb5.keytab if
543 necessary. This is the pre 3.4 behavior when
544 "use kerberos keytab" was true.*/
545 auth_ok
= ads_secrets_verify_ticket(context
, auth_context
,
546 host_princ
, ticket
, &tkt
, &keyblock
, &ret
);
549 /* Only fallback if we failed to decrypt the ticket */
550 if (ret
!= KRB5KRB_AP_ERR_TKT_NYV
&&
551 ret
!= KRB5KRB_AP_ERR_TKT_EXPIRED
&&
552 ret
!= KRB5KRB_AP_ERR_SKEW
) {
553 auth_ok
= ads_keytab_verify_ticket(context
,
554 auth_context
, ticket
, &tkt
, &keyblock
,
561 if ( use_replay_cache
) {
564 /* Heimdal leaks here, if we fix the leak, MIT crashes */
566 krb5_rc_close(context
, rcache
);
572 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
573 error_message(ret
)));
574 /* Try map the error return in case it's something like
575 * a clock skew error.
577 sret
= krb5_to_nt_status(ret
);
578 if (NT_STATUS_IS_OK(sret
) || NT_STATUS_EQUAL(sret
,NT_STATUS_UNSUCCESSFUL
)) {
579 sret
= NT_STATUS_LOGON_FAILURE
;
581 DEBUG(10,("ads_verify_ticket: returning error %s\n",
586 authtime
= get_authtime_from_tkt(tkt
);
587 client_principal
= get_principal_from_tkt(tkt
);
589 ret
= krb5_mk_rep(context
, auth_context
, &packet
);
591 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
592 error_message(ret
)));
596 *ap_rep
= data_blob(packet
.data
, packet
.length
);
598 kerberos_free_data_contents(context
, &packet
);
602 get_krb5_smb_session_key(context
, auth_context
, session_key
, True
);
603 dump_data_pw("SMB session key (from ticket)\n", session_key
->data
, session_key
->length
);
606 file_save("/tmp/ticket.dat", ticket
->data
, ticket
->length
);
609 /* continue when no PAC is retrieved or we couldn't decode the PAC
610 (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
611 Kerberos tickets encrypted using a DES key) - Guenther */
613 got_auth_data
= get_auth_data_from_tkt(mem_ctx
, &auth_data
, tkt
);
614 if (!got_auth_data
) {
615 DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
619 pac_ret
= decode_pac_data(mem_ctx
, &auth_data
, context
, keyblock
, client_principal
, authtime
, pac_data
);
620 if (!NT_STATUS_IS_OK(pac_ret
)) {
621 DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret
)));
624 data_blob_free(&auth_data
);
628 #if defined(HAVE_KRB5_TKT_ENC_PART2)
630 if (tkt
->enc_part2
) {
631 file_save("/tmp/authdata.dat",
632 tkt
->enc_part2
->authorization_data
[0]->contents
,
633 tkt
->enc_part2
->authorization_data
[0]->length
);
637 if (tkt
->ticket
.authorization_data
) {
638 file_save("/tmp/authdata.dat",
639 tkt
->ticket
.authorization_data
->val
->ad_data
.data
,
640 tkt
->ticket
.authorization_data
->val
->ad_data
.length
);
645 if ((ret
= smb_krb5_unparse_name(context
, client_principal
, principal
))) {
646 DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
647 error_message(ret
)));
648 sret
= NT_STATUS_LOGON_FAILURE
;
658 if (!NT_STATUS_IS_OK(sret
)) {
659 data_blob_free(&auth_data
);
662 if (!NT_STATUS_IS_OK(sret
)) {
663 data_blob_free(ap_rep
);
667 krb5_free_principal(context
, host_princ
);
671 krb5_free_keyblock(context
, keyblock
);
675 krb5_free_ticket(context
, tkt
);
678 SAFE_FREE(host_princ_s
);
681 krb5_auth_con_free(context
, auth_context
);
685 krb5_free_context(context
);
691 #endif /* HAVE_KRB5 */