2 Unix SMB/CIFS implementation.
4 kpasswd Server implementation
6 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
7 Copyright (C) Andrew Tridgell 2005
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include "smbd/service_task.h"
26 #include "lib/events/events.h"
27 #include "lib/socket/socket.h"
29 #include "system/network.h"
30 #include "lib/util/dlinklist.h"
31 #include "lib/ldb/include/ldb.h"
32 #include "heimdal/lib/krb5/krb5_locl.h"
33 #include "heimdal/lib/krb5/krb5-private.h"
34 #include "auth/gensec/gensec.h"
35 #include "auth/credentials/credentials.h"
36 #include "auth/credentials/credentials_krb5.h"
37 #include "auth/auth.h"
38 #include "dsdb/samdb/samdb.h"
39 #include "rpc_server/dcerpc_server.h"
40 #include "rpc_server/samr/proto.h"
41 #include "libcli/security/security.h"
43 /* hold information about one kdc socket */
44 struct kpasswd_socket
{
45 struct socket_context
*sock
;
46 struct kdc_server
*kdc
;
49 /* a queue of outgoing replies that have been deferred */
50 struct kdc_reply
*send_queue
;
53 /* Return true if there is a valid error packet formed in the error_blob */
54 static BOOL
kpasswdd_make_error_reply(struct kdc_server
*kdc
,
57 const char *error_string
,
58 DATA_BLOB
*error_blob
)
60 char *error_string_utf8
;
63 DEBUG(result_code
? 3 : 10, ("kpasswdd: %s\n", error_string
));
65 len
= push_utf8_talloc(mem_ctx
, &error_string_utf8
, error_string
);
70 *error_blob
= data_blob_talloc(mem_ctx
, NULL
, 2 + len
+ 1);
71 if (!error_blob
->data
) {
74 RSSVAL(error_blob
->data
, 0, result_code
);
75 memcpy(error_blob
->data
+ 2, error_string_utf8
, len
+ 1);
79 /* Return true if there is a valid error packet formed in the error_blob */
80 static BOOL
kpasswdd_make_unauth_error_reply(struct kdc_server
*kdc
,
83 const char *error_string
,
84 DATA_BLOB
*error_blob
)
88 DATA_BLOB error_bytes
;
89 krb5_data k5_error_bytes
, k5_error_blob
;
90 ret
= kpasswdd_make_error_reply(kdc
, mem_ctx
, result_code
, error_string
,
95 k5_error_bytes
.data
= error_bytes
.data
;
96 k5_error_bytes
.length
= error_bytes
.length
;
97 kret
= krb5_mk_error(kdc
->smb_krb5_context
->krb5_context
,
98 result_code
, NULL
, &k5_error_bytes
,
99 NULL
, NULL
, NULL
, NULL
, &k5_error_blob
);
103 *error_blob
= data_blob_talloc(mem_ctx
, k5_error_blob
.data
, k5_error_blob
.length
);
104 krb5_data_free(&k5_error_blob
);
105 if (!error_blob
->data
) {
111 static BOOL
kpasswd_make_pwchange_reply(struct kdc_server
*kdc
,
114 enum samr_RejectReason reject_reason
,
115 struct samr_DomInfo1
*dominfo
,
116 DATA_BLOB
*error_blob
)
118 if (NT_STATUS_EQUAL(status
, NT_STATUS_NO_SUCH_USER
)) {
119 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
120 KRB5_KPASSWD_ACCESSDENIED
,
121 "No such user when changing password",
124 if (NT_STATUS_EQUAL(status
, NT_STATUS_ACCESS_DENIED
)) {
125 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
126 KRB5_KPASSWD_ACCESSDENIED
,
127 "Not permitted to change password",
130 if (dominfo
&& NT_STATUS_EQUAL(status
, NT_STATUS_PASSWORD_RESTRICTION
)) {
131 const char *reject_string
;
132 switch (reject_reason
) {
133 case SAMR_REJECT_TOO_SHORT
:
134 reject_string
= talloc_asprintf(mem_ctx
, "Password too short, password must be at least %d characters long",
135 dominfo
->min_password_length
);
137 case SAMR_REJECT_COMPLEXITY
:
138 reject_string
= "Password does not meet complexity requirements";
140 case SAMR_REJECT_IN_HISTORY
:
141 reject_string
= "Password is already in password history";
143 case SAMR_REJECT_OTHER
:
145 reject_string
= talloc_asprintf(mem_ctx
, "Password must be at least %d characters long, and cannot match any of your %d previous passwords",
146 dominfo
->min_password_length
, dominfo
->password_history_length
);
149 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
150 KRB5_KPASSWD_SOFTERROR
,
154 if (!NT_STATUS_IS_OK(status
)) {
155 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
156 KRB5_KPASSWD_HARDERROR
,
157 talloc_asprintf(mem_ctx
, "failed to set password: %s", nt_errstr(status
)),
161 return kpasswdd_make_error_reply(kdc
, mem_ctx
, KRB5_KPASSWD_SUCCESS
,
167 A user password change
169 Return true if there is a valid error packet (or sucess) formed in
172 static BOOL
kpasswdd_change_password(struct kdc_server
*kdc
,
174 struct auth_session_info
*session_info
,
175 const char *password
,
179 enum samr_RejectReason reject_reason
;
180 struct samr_DomInfo1
*dominfo
;
181 struct ldb_context
*samdb
;
183 samdb
= samdb_connect(mem_ctx
, system_session(mem_ctx
));
185 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
186 KRB5_KPASSWD_HARDERROR
,
187 "Failed to open samdb",
191 DEBUG(3, ("Changing password of %s\\%s (%s)\n",
192 session_info
->server_info
->domain_name
,
193 session_info
->server_info
->account_name
,
194 dom_sid_string(mem_ctx
, session_info
->security_token
->user_sid
)));
196 /* User password change */
197 status
= samdb_set_password_sid(samdb
, mem_ctx
,
198 session_info
->security_token
->user_sid
,
199 password
, NULL
, NULL
,
200 True
, /* this is a user password change */
201 True
, /* run restriction tests */
204 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
212 static BOOL
kpasswd_process_request(struct kdc_server
*kdc
,
214 struct gensec_security
*gensec_security
,
219 struct auth_session_info
*session_info
;
220 if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security
,
222 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
223 KRB5_KPASSWD_HARDERROR
,
224 "gensec_session_info failed!",
229 case KRB5_KPASSWD_VERS_CHANGEPW
:
231 char *password
= talloc_strndup(mem_ctx
, (const char *)input
->data
, input
->length
);
235 return kpasswdd_change_password(kdc
, mem_ctx
, session_info
,
239 case KRB5_KPASSWD_VERS_SETPW
:
242 enum samr_RejectReason reject_reason
= SAMR_REJECT_OTHER
;
243 struct samr_DomInfo1
*dominfo
= NULL
;
244 struct ldb_context
*samdb
;
245 struct ldb_message
*msg
;
246 krb5_context context
= kdc
->smb_krb5_context
->krb5_context
;
248 ChangePasswdDataMS chpw
;
251 krb5_principal principal
;
252 char *set_password_on_princ
;
253 struct ldb_dn
*set_password_on_dn
;
258 msg
= ldb_msg_new(mem_ctx
);
263 ret
= decode_ChangePasswdDataMS(input
->data
, input
->length
,
266 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
267 KRB5_KPASSWD_MALFORMED
,
268 "failed to decode password change structure",
272 password
= talloc_strndup(mem_ctx
, chpw
.newpasswd
.data
,
273 chpw
.newpasswd
.length
);
275 free_ChangePasswdDataMS(&chpw
);
278 if ((chpw
.targname
&& !chpw
.targrealm
)
279 || (!chpw
.targname
&& chpw
.targrealm
)) {
280 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
281 KRB5_KPASSWD_MALFORMED
,
282 "Realm and principal must be both present, or neither present",
285 if (chpw
.targname
&& chpw
.targrealm
) {
286 if (_krb5_principalname2krb5_principal(kdc
->smb_krb5_context
->krb5_context
,
287 &principal
, *chpw
.targname
,
288 *chpw
.targrealm
) != 0) {
289 free_ChangePasswdDataMS(&chpw
);
290 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
291 KRB5_KPASSWD_MALFORMED
,
292 "failed to extract principal to set",
297 free_ChangePasswdDataMS(&chpw
);
298 return kpasswdd_change_password(kdc
, mem_ctx
, session_info
,
301 free_ChangePasswdDataMS(&chpw
);
303 if (krb5_unparse_name(context
, principal
, &set_password_on_princ
) != 0) {
304 krb5_free_principal(context
, principal
);
305 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
306 KRB5_KPASSWD_MALFORMED
,
307 "krb5_unparse_name failed!",
311 krb5_free_principal(context
, principal
);
313 samdb
= samdb_connect(mem_ctx
, session_info
);
315 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
316 KRB5_KPASSWD_HARDERROR
,
317 "Unable to open database!",
321 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
322 session_info
->server_info
->domain_name
,
323 session_info
->server_info
->account_name
,
324 dom_sid_string(mem_ctx
, session_info
->security_token
->user_sid
),
325 set_password_on_princ
));
326 ret
= ldb_transaction_start(samdb
);
328 status
= NT_STATUS_TRANSACTION_ABORTED
;
329 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
336 status
= crack_user_principal_name(samdb
, mem_ctx
,
337 set_password_on_princ
,
338 &set_password_on_dn
, NULL
);
339 free(set_password_on_princ
);
340 if (!NT_STATUS_IS_OK(status
)) {
341 ldb_transaction_cancel(samdb
);
342 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
349 msg
= ldb_msg_new(mem_ctx
);
351 ldb_transaction_cancel(samdb
);
352 status
= NT_STATUS_NO_MEMORY
;
354 msg
->dn
= ldb_dn_copy(msg
, set_password_on_dn
);
356 status
= NT_STATUS_NO_MEMORY
;
360 if (NT_STATUS_IS_OK(status
)) {
361 /* Admin password set */
362 status
= samdb_set_password(samdb
, mem_ctx
,
363 set_password_on_dn
, NULL
,
364 msg
, password
, NULL
, NULL
,
365 False
, /* this is not a user password change */
366 True
, /* run restriction tests */
367 &reject_reason
, &dominfo
);
370 if (NT_STATUS_IS_OK(status
)) {
371 /* modify the samdb record */
372 ret
= samdb_replace(samdb
, mem_ctx
, msg
);
374 DEBUG(2,("Failed to modify record to set password on %s: %s\n",
375 ldb_dn_get_linearized(msg
->dn
),
376 ldb_errstring(samdb
)));
377 status
= NT_STATUS_ACCESS_DENIED
;
380 if (NT_STATUS_IS_OK(status
)) {
381 ret
= ldb_transaction_commit(samdb
);
383 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
384 ldb_dn_get_linearized(msg
->dn
),
385 ldb_errstring(samdb
)));
386 status
= NT_STATUS_TRANSACTION_ABORTED
;
389 ldb_transaction_cancel(samdb
);
391 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
398 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
399 KRB5_KPASSWD_BAD_VERSION
,
400 talloc_asprintf(mem_ctx
,
401 "Protocol version %u not supported",
408 BOOL
kpasswdd_process(struct kdc_server
*kdc
,
412 struct socket_address
*peer_addr
,
413 struct socket_address
*my_addr
,
417 const uint16_t header_len
= 6;
420 uint16_t krb_priv_len
;
423 DATA_BLOB ap_req
, krb_priv_req
;
424 DATA_BLOB krb_priv_rep
= data_blob(NULL
, 0);
425 DATA_BLOB ap_rep
= data_blob(NULL
, 0);
426 DATA_BLOB kpasswd_req
, kpasswd_rep
;
427 struct cli_credentials
*server_credentials
;
428 struct gensec_security
*gensec_security
;
429 TALLOC_CTX
*tmp_ctx
= talloc_new(mem_ctx
);
435 /* Be parinoid. We need to ensure we don't just let the
436 * caller lead us into a buffer overflow */
437 if (input
->length
<= header_len
) {
438 talloc_free(tmp_ctx
);
442 len
= RSVAL(input
->data
, 0);
443 if (input
->length
!= len
) {
444 talloc_free(tmp_ctx
);
448 /* There are two different versions of this protocol so far,
449 * plus others in the standards pipe. Fortunetly they all
450 * take a very similar framing */
451 version
= RSVAL(input
->data
, 2);
452 ap_req_len
= RSVAL(input
->data
, 4);
453 if ((ap_req_len
>= len
) || (ap_req_len
+ header_len
) >= len
) {
454 talloc_free(tmp_ctx
);
458 krb_priv_len
= len
- ap_req_len
;
459 ap_req
= data_blob_const(&input
->data
[header_len
], ap_req_len
);
460 krb_priv_req
= data_blob_const(&input
->data
[header_len
+ ap_req_len
], krb_priv_len
);
462 nt_status
= gensec_server_start(tmp_ctx
, kdc
->task
->event_ctx
, kdc
->task
->msg_ctx
, &gensec_security
);
463 if (!NT_STATUS_IS_OK(nt_status
)) {
464 talloc_free(tmp_ctx
);
468 server_credentials
= cli_credentials_init(tmp_ctx
);
469 if (!server_credentials
) {
470 DEBUG(1, ("Failed to init server credentials\n"));
474 /* We want the credentials subsystem to use the krb5 context
475 * we already have, rather than a new context */
476 cli_credentials_set_krb5_context(server_credentials
, kdc
->smb_krb5_context
);
477 cli_credentials_set_conf(server_credentials
);
478 nt_status
= cli_credentials_set_stored_principal(server_credentials
, "kadmin/changepw");
479 if (!NT_STATUS_IS_OK(nt_status
)) {
480 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
481 KRB5_KPASSWD_HARDERROR
,
482 talloc_asprintf(mem_ctx
,
483 "Failed to obtain server credentials for kadmin/changepw: %s\n",
484 nt_errstr(nt_status
)),
490 talloc_free(tmp_ctx
);
494 nt_status
= gensec_set_credentials(gensec_security
, server_credentials
);
495 if (!NT_STATUS_IS_OK(nt_status
)) {
496 talloc_free(tmp_ctx
);
500 /* The kerberos PRIV packets include these addresses. MIT
501 * clients check that they are present */
502 nt_status
= gensec_set_peer_addr(gensec_security
, peer_addr
);
503 if (!NT_STATUS_IS_OK(nt_status
)) {
504 talloc_free(tmp_ctx
);
507 nt_status
= gensec_set_my_addr(gensec_security
, my_addr
);
508 if (!NT_STATUS_IS_OK(nt_status
)) {
509 talloc_free(tmp_ctx
);
513 /* We want the GENSEC wrap calls to generate PRIV tokens */
514 gensec_want_feature(gensec_security
, GENSEC_FEATURE_SEAL
);
516 nt_status
= gensec_start_mech_by_name(gensec_security
, "krb5");
517 if (!NT_STATUS_IS_OK(nt_status
)) {
518 talloc_free(tmp_ctx
);
522 /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
523 nt_status
= gensec_update(gensec_security
, tmp_ctx
, ap_req
, &ap_rep
);
524 if (!NT_STATUS_IS_OK(nt_status
) && !NT_STATUS_EQUAL(nt_status
, NT_STATUS_MORE_PROCESSING_REQUIRED
)) {
526 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
527 KRB5_KPASSWD_HARDERROR
,
528 talloc_asprintf(mem_ctx
,
529 "gensec_update failed: %s",
530 nt_errstr(nt_status
)),
536 talloc_free(tmp_ctx
);
540 /* Extract the data from the KRB-PRIV half of the message */
541 nt_status
= gensec_unwrap(gensec_security
, tmp_ctx
, &krb_priv_req
, &kpasswd_req
);
542 if (!NT_STATUS_IS_OK(nt_status
)) {
543 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
544 KRB5_KPASSWD_HARDERROR
,
545 talloc_asprintf(mem_ctx
,
546 "gensec_unwrap failed: %s",
547 nt_errstr(nt_status
)),
553 talloc_free(tmp_ctx
);
557 /* Figure out something to do with it (probably changing a password...) */
558 ret
= kpasswd_process_request(kdc
, tmp_ctx
,
561 &kpasswd_req
, &kpasswd_rep
);
567 /* And wrap up the reply: This ensures that the error message
568 * or success can be verified by the client */
569 nt_status
= gensec_wrap(gensec_security
, tmp_ctx
,
570 &kpasswd_rep
, &krb_priv_rep
);
571 if (!NT_STATUS_IS_OK(nt_status
)) {
572 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
573 KRB5_KPASSWD_HARDERROR
,
574 talloc_asprintf(mem_ctx
,
575 "gensec_wrap failed: %s",
576 nt_errstr(nt_status
)),
582 talloc_free(tmp_ctx
);
587 *reply
= data_blob_talloc(mem_ctx
, NULL
, krb_priv_rep
.length
+ ap_rep
.length
+ header_len
);
592 RSSVAL(reply
->data
, 0, reply
->length
);
593 RSSVAL(reply
->data
, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
594 RSSVAL(reply
->data
, 4, ap_rep
.length
);
595 memcpy(reply
->data
+ header_len
,
598 memcpy(reply
->data
+ header_len
+ ap_rep
.length
,
600 krb_priv_rep
.length
);
602 talloc_free(tmp_ctx
);