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 3 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, see <http://www.gnu.org/licenses/>.
24 #include "smbd/service_task.h"
25 #include "lib/events/events.h"
26 #include "lib/socket/socket.h"
27 #include "system/network.h"
28 #include "../lib/util/dlinklist.h"
29 #include "lib/ldb/include/ldb.h"
30 #include "auth/gensec/gensec.h"
31 #include "auth/credentials/credentials.h"
32 #include "auth/credentials/credentials_krb5.h"
33 #include "auth/auth.h"
34 #include "dsdb/samdb/samdb.h"
35 #include "rpc_server/dcerpc_server.h"
36 #include "rpc_server/samr/proto.h"
37 #include "libcli/security/security.h"
38 #include "param/param.h"
41 /* TODO: remove all SAMBA4_INTERNAL_HEIMDAL stuff from this file */
42 #ifdef SAMBA4_INTERNAL_HEIMDAL
43 #include "heimdal_build/kpasswdd-glue.h"
46 /* hold information about one kdc socket */
47 struct kpasswd_socket
{
48 struct socket_context
*sock
;
49 struct kdc_server
*kdc
;
50 struct tevent_fd
*fde
;
52 /* a queue of outgoing replies that have been deferred */
53 struct kdc_reply
*send_queue
;
56 /* Return true if there is a valid error packet formed in the error_blob */
57 static bool kpasswdd_make_error_reply(struct kdc_server
*kdc
,
60 const char *error_string
,
61 DATA_BLOB
*error_blob
)
63 char *error_string_utf8
;
66 DEBUG(result_code
? 3 : 10, ("kpasswdd: %s\n", error_string
));
68 if (!push_utf8_talloc(mem_ctx
, &error_string_utf8
, error_string
, &len
)) {
72 *error_blob
= data_blob_talloc(mem_ctx
, NULL
, 2 + len
+ 1);
73 if (!error_blob
->data
) {
76 RSSVAL(error_blob
->data
, 0, result_code
);
77 memcpy(error_blob
->data
+ 2, error_string_utf8
, len
+ 1);
81 /* Return true if there is a valid error packet formed in the error_blob */
82 static bool kpasswdd_make_unauth_error_reply(struct kdc_server
*kdc
,
85 const char *error_string
,
86 DATA_BLOB
*error_blob
)
90 DATA_BLOB error_bytes
;
91 krb5_data k5_error_bytes
, k5_error_blob
;
92 ret
= kpasswdd_make_error_reply(kdc
, mem_ctx
, result_code
, error_string
,
97 k5_error_bytes
.data
= error_bytes
.data
;
98 k5_error_bytes
.length
= error_bytes
.length
;
99 kret
= krb5_mk_error(kdc
->smb_krb5_context
->krb5_context
,
100 result_code
, NULL
, &k5_error_bytes
,
101 NULL
, NULL
, NULL
, NULL
, &k5_error_blob
);
105 *error_blob
= data_blob_talloc(mem_ctx
, k5_error_blob
.data
, k5_error_blob
.length
);
106 krb5_data_free(&k5_error_blob
);
107 if (!error_blob
->data
) {
113 static bool kpasswd_make_pwchange_reply(struct kdc_server
*kdc
,
116 enum samr_RejectReason reject_reason
,
117 struct samr_DomInfo1
*dominfo
,
118 DATA_BLOB
*error_blob
)
120 if (NT_STATUS_EQUAL(status
, NT_STATUS_NO_SUCH_USER
)) {
121 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
122 KRB5_KPASSWD_ACCESSDENIED
,
123 "No such user when changing password",
126 if (NT_STATUS_EQUAL(status
, NT_STATUS_ACCESS_DENIED
)) {
127 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
128 KRB5_KPASSWD_ACCESSDENIED
,
129 "Not permitted to change password",
132 if (dominfo
&& NT_STATUS_EQUAL(status
, NT_STATUS_PASSWORD_RESTRICTION
)) {
133 const char *reject_string
;
134 switch (reject_reason
) {
135 case SAMR_REJECT_TOO_SHORT
:
136 reject_string
= talloc_asprintf(mem_ctx
, "Password too short, password must be at least %d characters long",
137 dominfo
->min_password_length
);
139 case SAMR_REJECT_COMPLEXITY
:
140 reject_string
= "Password does not meet complexity requirements";
142 case SAMR_REJECT_IN_HISTORY
:
143 reject_string
= "Password is already in password history";
145 case SAMR_REJECT_OTHER
:
147 reject_string
= talloc_asprintf(mem_ctx
, "Password must be at least %d characters long, and cannot match any of your %d previous passwords",
148 dominfo
->min_password_length
, dominfo
->password_history_length
);
151 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
152 KRB5_KPASSWD_SOFTERROR
,
156 if (!NT_STATUS_IS_OK(status
)) {
157 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
158 KRB5_KPASSWD_HARDERROR
,
159 talloc_asprintf(mem_ctx
, "failed to set password: %s", nt_errstr(status
)),
163 return kpasswdd_make_error_reply(kdc
, mem_ctx
, KRB5_KPASSWD_SUCCESS
,
169 A user password change
171 Return true if there is a valid error packet (or sucess) formed in
174 static bool kpasswdd_change_password(struct kdc_server
*kdc
,
176 struct auth_session_info
*session_info
,
177 const DATA_BLOB
*password
,
181 enum samr_RejectReason reject_reason
;
182 struct samr_DomInfo1
*dominfo
;
183 struct ldb_context
*samdb
;
185 samdb
= samdb_connect(mem_ctx
, kdc
->task
->event_ctx
, kdc
->task
->lp_ctx
, system_session(mem_ctx
, kdc
->task
->lp_ctx
));
187 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
188 KRB5_KPASSWD_HARDERROR
,
189 "Failed to open samdb",
193 DEBUG(3, ("Changing password of %s\\%s (%s)\n",
194 session_info
->server_info
->domain_name
,
195 session_info
->server_info
->account_name
,
196 dom_sid_string(mem_ctx
, session_info
->security_token
->user_sid
)));
198 /* User password change */
199 status
= samdb_set_password_sid(samdb
, mem_ctx
,
200 session_info
->security_token
->user_sid
,
201 password
, NULL
, NULL
,
202 true, /* this is a user password change */
205 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
213 static bool kpasswd_process_request(struct kdc_server
*kdc
,
215 struct gensec_security
*gensec_security
,
220 struct auth_session_info
*session_info
;
223 if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security
,
225 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
226 KRB5_KPASSWD_HARDERROR
,
227 "gensec_session_info failed!",
232 case KRB5_KPASSWD_VERS_CHANGEPW
:
235 if (!convert_string_talloc_convenience(mem_ctx
, lp_iconv_convenience(kdc
->task
->lp_ctx
),
237 (const char *)input
->data
,
239 (void **)&password
.data
, &pw_len
, false)) {
242 password
.length
= pw_len
;
244 return kpasswdd_change_password(kdc
, mem_ctx
, session_info
,
248 case KRB5_KPASSWD_VERS_SETPW
:
251 enum samr_RejectReason reject_reason
= SAMR_REJECT_OTHER
;
252 struct samr_DomInfo1
*dominfo
= NULL
;
253 struct ldb_context
*samdb
;
254 struct ldb_message
*msg
;
255 krb5_context context
= kdc
->smb_krb5_context
->krb5_context
;
257 ChangePasswdDataMS chpw
;
260 krb5_principal principal
;
261 char *set_password_on_princ
;
262 struct ldb_dn
*set_password_on_dn
;
267 msg
= ldb_msg_new(mem_ctx
);
272 ret
= decode_ChangePasswdDataMS(input
->data
, input
->length
,
275 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
276 KRB5_KPASSWD_MALFORMED
,
277 "failed to decode password change structure",
281 if (!convert_string_talloc_convenience(mem_ctx
, lp_iconv_convenience(kdc
->task
->lp_ctx
),
283 (const char *)chpw
.newpasswd
.data
,
284 chpw
.newpasswd
.length
,
285 (void **)&password
.data
, &pw_len
, false)) {
286 free_ChangePasswdDataMS(&chpw
);
290 password
.length
= pw_len
;
292 if ((chpw
.targname
&& !chpw
.targrealm
)
293 || (!chpw
.targname
&& chpw
.targrealm
)) {
294 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
295 KRB5_KPASSWD_MALFORMED
,
296 "Realm and principal must be both present, or neither present",
299 if (chpw
.targname
&& chpw
.targrealm
) {
300 #ifdef SAMBA4_INTERNAL_HEIMDAL
301 if (_krb5_principalname2krb5_principal(kdc
->smb_krb5_context
->krb5_context
,
302 &principal
, *chpw
.targname
,
303 *chpw
.targrealm
) != 0) {
304 free_ChangePasswdDataMS(&chpw
);
305 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
306 KRB5_KPASSWD_MALFORMED
,
307 "failed to extract principal to set",
311 #else /* SAMBA4_INTERNAL_HEIMDAL */
312 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
313 KRB5_KPASSWD_BAD_VERSION
,
314 "Operation Not Implemented",
316 #endif /* SAMBA4_INTERNAL_HEIMDAL */
318 free_ChangePasswdDataMS(&chpw
);
319 return kpasswdd_change_password(kdc
, mem_ctx
, session_info
,
322 free_ChangePasswdDataMS(&chpw
);
324 if (krb5_unparse_name(context
, principal
, &set_password_on_princ
) != 0) {
325 krb5_free_principal(context
, principal
);
326 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
327 KRB5_KPASSWD_MALFORMED
,
328 "krb5_unparse_name failed!",
332 krb5_free_principal(context
, principal
);
334 samdb
= samdb_connect(mem_ctx
, kdc
->task
->event_ctx
, kdc
->task
->lp_ctx
, session_info
);
336 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
337 KRB5_KPASSWD_HARDERROR
,
338 "Unable to open database!",
342 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
343 session_info
->server_info
->domain_name
,
344 session_info
->server_info
->account_name
,
345 dom_sid_string(mem_ctx
, session_info
->security_token
->user_sid
),
346 set_password_on_princ
));
347 ret
= ldb_transaction_start(samdb
);
349 status
= NT_STATUS_TRANSACTION_ABORTED
;
350 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
357 status
= crack_user_principal_name(samdb
, mem_ctx
,
358 set_password_on_princ
,
359 &set_password_on_dn
, NULL
);
360 free(set_password_on_princ
);
361 if (!NT_STATUS_IS_OK(status
)) {
362 ldb_transaction_cancel(samdb
);
363 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
370 msg
= ldb_msg_new(mem_ctx
);
372 ldb_transaction_cancel(samdb
);
373 status
= NT_STATUS_NO_MEMORY
;
375 msg
->dn
= ldb_dn_copy(msg
, set_password_on_dn
);
377 status
= NT_STATUS_NO_MEMORY
;
381 if (NT_STATUS_IS_OK(status
)) {
382 /* Admin password set */
383 status
= samdb_set_password(samdb
, mem_ctx
,
384 set_password_on_dn
, NULL
,
385 msg
, &password
, NULL
, NULL
,
386 false, /* this is not a user password change */
387 &reject_reason
, &dominfo
);
390 if (NT_STATUS_IS_OK(status
)) {
391 /* modify the samdb record */
392 ret
= samdb_replace(samdb
, mem_ctx
, msg
);
394 DEBUG(2,("Failed to modify record to set password on %s: %s\n",
395 ldb_dn_get_linearized(msg
->dn
),
396 ldb_errstring(samdb
)));
397 status
= NT_STATUS_ACCESS_DENIED
;
400 if (NT_STATUS_IS_OK(status
)) {
401 ret
= ldb_transaction_commit(samdb
);
403 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
404 ldb_dn_get_linearized(msg
->dn
),
405 ldb_errstring(samdb
)));
406 status
= NT_STATUS_TRANSACTION_ABORTED
;
409 ldb_transaction_cancel(samdb
);
411 return kpasswd_make_pwchange_reply(kdc
, mem_ctx
,
418 return kpasswdd_make_error_reply(kdc
, mem_ctx
,
419 KRB5_KPASSWD_BAD_VERSION
,
420 talloc_asprintf(mem_ctx
,
421 "Protocol version %u not supported",
428 bool kpasswdd_process(struct kdc_server
*kdc
,
432 struct socket_address
*peer_addr
,
433 struct socket_address
*my_addr
,
437 const uint16_t header_len
= 6;
440 uint16_t krb_priv_len
;
443 DATA_BLOB ap_req
, krb_priv_req
;
444 DATA_BLOB krb_priv_rep
= data_blob(NULL
, 0);
445 DATA_BLOB ap_rep
= data_blob(NULL
, 0);
446 DATA_BLOB kpasswd_req
, kpasswd_rep
;
447 struct cli_credentials
*server_credentials
;
448 struct gensec_security
*gensec_security
;
449 TALLOC_CTX
*tmp_ctx
= talloc_new(mem_ctx
);
455 /* Be parinoid. We need to ensure we don't just let the
456 * caller lead us into a buffer overflow */
457 if (input
->length
<= header_len
) {
458 talloc_free(tmp_ctx
);
462 len
= RSVAL(input
->data
, 0);
463 if (input
->length
!= len
) {
464 talloc_free(tmp_ctx
);
468 /* There are two different versions of this protocol so far,
469 * plus others in the standards pipe. Fortunetly they all
470 * take a very similar framing */
471 version
= RSVAL(input
->data
, 2);
472 ap_req_len
= RSVAL(input
->data
, 4);
473 if ((ap_req_len
>= len
) || (ap_req_len
+ header_len
) >= len
) {
474 talloc_free(tmp_ctx
);
478 krb_priv_len
= len
- ap_req_len
;
479 ap_req
= data_blob_const(&input
->data
[header_len
], ap_req_len
);
480 krb_priv_req
= data_blob_const(&input
->data
[header_len
+ ap_req_len
], krb_priv_len
);
482 server_credentials
= cli_credentials_init(tmp_ctx
);
483 if (!server_credentials
) {
484 DEBUG(1, ("Failed to init server credentials\n"));
488 /* We want the credentials subsystem to use the krb5 context
489 * we already have, rather than a new context */
490 cli_credentials_set_krb5_context(server_credentials
, kdc
->smb_krb5_context
);
491 cli_credentials_set_conf(server_credentials
, kdc
->task
->lp_ctx
);
492 nt_status
= cli_credentials_set_stored_principal(server_credentials
, kdc
->task
->event_ctx
, kdc
->task
->lp_ctx
, "kadmin/changepw");
493 if (!NT_STATUS_IS_OK(nt_status
)) {
494 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
495 KRB5_KPASSWD_HARDERROR
,
496 talloc_asprintf(mem_ctx
,
497 "Failed to obtain server credentials for kadmin/changepw: %s\n",
498 nt_errstr(nt_status
)),
504 talloc_free(tmp_ctx
);
508 /* We don't strictly need to call this wrapper, and could call
509 * gensec_server_start directly, as we have no need for NTLM
510 * and we have a PAC, but this ensures that the wrapper can be
511 * safely extended for other helpful things in future */
512 nt_status
= samba_server_gensec_start(tmp_ctx
, kdc
->task
->event_ctx
,
518 if (!NT_STATUS_IS_OK(nt_status
)) {
519 talloc_free(tmp_ctx
);
523 /* The kerberos PRIV packets include these addresses. MIT
524 * clients check that they are present */
525 nt_status
= gensec_set_peer_addr(gensec_security
, peer_addr
);
526 if (!NT_STATUS_IS_OK(nt_status
)) {
527 talloc_free(tmp_ctx
);
530 nt_status
= gensec_set_my_addr(gensec_security
, my_addr
);
531 if (!NT_STATUS_IS_OK(nt_status
)) {
532 talloc_free(tmp_ctx
);
536 /* We want the GENSEC wrap calls to generate PRIV tokens */
537 gensec_want_feature(gensec_security
, GENSEC_FEATURE_SEAL
);
539 nt_status
= gensec_start_mech_by_name(gensec_security
, "krb5");
540 if (!NT_STATUS_IS_OK(nt_status
)) {
541 talloc_free(tmp_ctx
);
545 /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
546 nt_status
= gensec_update(gensec_security
, tmp_ctx
, ap_req
, &ap_rep
);
547 if (!NT_STATUS_IS_OK(nt_status
) && !NT_STATUS_EQUAL(nt_status
, NT_STATUS_MORE_PROCESSING_REQUIRED
)) {
549 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
550 KRB5_KPASSWD_HARDERROR
,
551 talloc_asprintf(mem_ctx
,
552 "gensec_update failed: %s",
553 nt_errstr(nt_status
)),
559 talloc_free(tmp_ctx
);
563 /* Extract the data from the KRB-PRIV half of the message */
564 nt_status
= gensec_unwrap(gensec_security
, tmp_ctx
, &krb_priv_req
, &kpasswd_req
);
565 if (!NT_STATUS_IS_OK(nt_status
)) {
566 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
567 KRB5_KPASSWD_HARDERROR
,
568 talloc_asprintf(mem_ctx
,
569 "gensec_unwrap failed: %s",
570 nt_errstr(nt_status
)),
576 talloc_free(tmp_ctx
);
580 /* Figure out something to do with it (probably changing a password...) */
581 ret
= kpasswd_process_request(kdc
, tmp_ctx
,
584 &kpasswd_req
, &kpasswd_rep
);
590 /* And wrap up the reply: This ensures that the error message
591 * or success can be verified by the client */
592 nt_status
= gensec_wrap(gensec_security
, tmp_ctx
,
593 &kpasswd_rep
, &krb_priv_rep
);
594 if (!NT_STATUS_IS_OK(nt_status
)) {
595 ret
= kpasswdd_make_unauth_error_reply(kdc
, mem_ctx
,
596 KRB5_KPASSWD_HARDERROR
,
597 talloc_asprintf(mem_ctx
,
598 "gensec_wrap failed: %s",
599 nt_errstr(nt_status
)),
605 talloc_free(tmp_ctx
);
610 *reply
= data_blob_talloc(mem_ctx
, NULL
, krb_priv_rep
.length
+ ap_rep
.length
+ header_len
);
615 RSSVAL(reply
->data
, 0, reply
->length
);
616 RSSVAL(reply
->data
, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
617 RSSVAL(reply
->data
, 4, ap_rep
.length
);
618 memcpy(reply
->data
+ header_len
,
621 memcpy(reply
->data
+ header_len
+ ap_rep
.length
,
623 krb_priv_rep
.length
);
625 talloc_free(tmp_ctx
);