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 "lib/tsocket/tsocket.h"
28 #include "system/network.h"
29 #include "../lib/util/dlinklist.h"
30 #include "lib/ldb/include/ldb.h"
31 #include "auth/gensec/gensec.h"
32 #include "auth/credentials/credentials.h"
33 #include "auth/credentials/credentials_krb5.h"
34 #include "auth/auth.h"
35 #include "dsdb/samdb/samdb.h"
36 #include "rpc_server/dcerpc_server.h"
37 #include "rpc_server/samr/proto.h"
38 #include "libcli/security/security.h"
39 #include "param/param.h"
42 /* TODO: remove all SAMBA4_INTERNAL_HEIMDAL stuff from this file */
43 #ifdef SAMBA4_INTERNAL_HEIMDAL
44 #include "heimdal_build/kpasswdd-glue.h"
47 /* Return true if there is a valid error packet formed in the error_blob */
48 static bool kpasswdd_make_error_reply(struct kdc_server *kdc,
51 const char *error_string,
52 DATA_BLOB *error_blob)
54 char *error_string_utf8;
57 DEBUG(result_code ? 3 : 10, ("kpasswdd: %s\n", error_string));
59 if (!push_utf8_talloc(mem_ctx, &error_string_utf8, error_string, &len)) {
63 *error_blob = data_blob_talloc(mem_ctx, NULL, 2 + len + 1);
64 if (!error_blob->data) {
67 RSSVAL(error_blob->data, 0, result_code);
68 memcpy(error_blob->data + 2, error_string_utf8, len + 1);
72 /* Return true if there is a valid error packet formed in the error_blob */
73 static bool kpasswdd_make_unauth_error_reply(struct kdc_server *kdc,
76 const char *error_string,
77 DATA_BLOB *error_blob)
81 DATA_BLOB error_bytes;
82 krb5_data k5_error_bytes, k5_error_blob;
83 ret = kpasswdd_make_error_reply(kdc, mem_ctx, result_code, error_string,
88 k5_error_bytes.data = error_bytes.data;
89 k5_error_bytes.length = error_bytes.length;
90 kret = krb5_mk_error(kdc->smb_krb5_context->krb5_context,
91 result_code, NULL, &k5_error_bytes,
92 NULL, NULL, NULL, NULL, &k5_error_blob);
96 *error_blob = data_blob_talloc(mem_ctx, k5_error_blob.data, k5_error_blob.length);
97 krb5_data_free(&k5_error_blob);
98 if (!error_blob->data) {
104 static bool kpasswd_make_pwchange_reply(struct kdc_server *kdc,
107 enum samPwdChangeReason reject_reason,
108 struct samr_DomInfo1 *dominfo,
109 DATA_BLOB *error_blob)
111 if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_USER)) {
112 return kpasswdd_make_error_reply(kdc, mem_ctx,
113 KRB5_KPASSWD_ACCESSDENIED,
114 "No such user when changing password",
117 if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
118 return kpasswdd_make_error_reply(kdc, mem_ctx,
119 KRB5_KPASSWD_ACCESSDENIED,
120 "Not permitted to change password",
123 if (dominfo && NT_STATUS_EQUAL(status, NT_STATUS_PASSWORD_RESTRICTION)) {
124 const char *reject_string;
125 switch (reject_reason) {
126 case SAM_PWD_CHANGE_PASSWORD_TOO_SHORT:
127 reject_string = talloc_asprintf(mem_ctx, "Password too short, password must be at least %d characters long",
128 dominfo->min_password_length);
130 case SAM_PWD_CHANGE_NOT_COMPLEX:
131 reject_string = "Password does not meet complexity requirements";
133 case SAM_PWD_CHANGE_PWD_IN_HISTORY:
134 reject_string = "Password is already in password history";
137 reject_string = talloc_asprintf(mem_ctx, "Password must be at least %d characters long, and cannot match any of your %d previous passwords",
138 dominfo->min_password_length, dominfo->password_history_length);
141 return kpasswdd_make_error_reply(kdc, mem_ctx,
142 KRB5_KPASSWD_SOFTERROR,
146 if (!NT_STATUS_IS_OK(status)) {
147 return kpasswdd_make_error_reply(kdc, mem_ctx,
148 KRB5_KPASSWD_HARDERROR,
149 talloc_asprintf(mem_ctx, "failed to set password: %s", nt_errstr(status)),
153 return kpasswdd_make_error_reply(kdc, mem_ctx, KRB5_KPASSWD_SUCCESS,
159 A user password change
161 Return true if there is a valid error packet (or success) formed in
164 static bool kpasswdd_change_password(struct kdc_server *kdc,
166 struct auth_session_info *session_info,
167 const DATA_BLOB *password,
171 enum samPwdChangeReason reject_reason;
172 struct samr_DomInfo1 *dominfo;
173 struct ldb_context *samdb;
175 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, system_session(kdc->task->lp_ctx));
177 return kpasswdd_make_error_reply(kdc, mem_ctx,
178 KRB5_KPASSWD_HARDERROR,
179 "Failed to open samdb",
183 DEBUG(3, ("Changing password of %s\\%s (%s)\n",
184 session_info->server_info->domain_name,
185 session_info->server_info->account_name,
186 dom_sid_string(mem_ctx, session_info->security_token->user_sid)));
188 /* User password change */
189 status = samdb_set_password_sid(samdb, mem_ctx,
190 session_info->security_token->user_sid,
191 password, NULL, NULL,
192 true, /* this is a user password change */
195 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
203 static bool kpasswd_process_request(struct kdc_server *kdc,
205 struct gensec_security *gensec_security,
210 struct auth_session_info *session_info;
213 if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security,
215 return kpasswdd_make_error_reply(kdc, mem_ctx,
216 KRB5_KPASSWD_HARDERROR,
217 "gensec_session_info failed!",
222 case KRB5_KPASSWD_VERS_CHANGEPW:
225 if (!convert_string_talloc_convenience(mem_ctx, lp_iconv_convenience(kdc->task->lp_ctx),
227 (const char *)input->data,
229 (void **)&password.data, &pw_len, false)) {
232 password.length = pw_len;
234 return kpasswdd_change_password(kdc, mem_ctx, session_info,
238 case KRB5_KPASSWD_VERS_SETPW:
241 enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
242 struct samr_DomInfo1 *dominfo = NULL;
243 struct ldb_context *samdb;
244 struct ldb_message *msg;
245 krb5_context context = kdc->smb_krb5_context->krb5_context;
247 ChangePasswdDataMS chpw;
250 krb5_principal principal;
251 char *set_password_on_princ;
252 struct ldb_dn *set_password_on_dn;
253 bool service_principal_name = false;
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 if (!convert_string_talloc_convenience(mem_ctx, lp_iconv_convenience(kdc->task->lp_ctx),
274 (const char *)chpw.newpasswd.data,
275 chpw.newpasswd.length,
276 (void **)&password.data, &pw_len, false)) {
277 free_ChangePasswdDataMS(&chpw);
281 password.length = pw_len;
283 if ((chpw.targname && !chpw.targrealm)
284 || (!chpw.targname && chpw.targrealm)) {
285 return kpasswdd_make_error_reply(kdc, mem_ctx,
286 KRB5_KPASSWD_MALFORMED,
287 "Realm and principal must be both present, or neither present",
290 if (chpw.targname && chpw.targrealm) {
291 #ifdef SAMBA4_INTERNAL_HEIMDAL
292 if (_krb5_principalname2krb5_principal(kdc->smb_krb5_context->krb5_context,
293 &principal, *chpw.targname,
294 *chpw.targrealm) != 0) {
295 free_ChangePasswdDataMS(&chpw);
296 return kpasswdd_make_error_reply(kdc, mem_ctx,
297 KRB5_KPASSWD_MALFORMED,
298 "failed to extract principal to set",
302 #else /* SAMBA4_INTERNAL_HEIMDAL */
303 return kpasswdd_make_error_reply(kdc, mem_ctx,
304 KRB5_KPASSWD_BAD_VERSION,
305 "Operation Not Implemented",
307 #endif /* SAMBA4_INTERNAL_HEIMDAL */
309 free_ChangePasswdDataMS(&chpw);
310 return kpasswdd_change_password(kdc, mem_ctx, session_info,
313 free_ChangePasswdDataMS(&chpw);
315 if (principal->name.name_string.len >= 2) {
316 service_principal_name = true;
318 /* We use this, rather than 'no realm' flag,
319 * as we don't want to accept a password
320 * change on a principal from another realm */
322 if (krb5_unparse_name_short(context, principal, &set_password_on_princ) != 0) {
323 krb5_free_principal(context, principal);
324 return kpasswdd_make_error_reply(kdc, mem_ctx,
325 KRB5_KPASSWD_MALFORMED,
326 "krb5_unparse_name failed!",
330 if (krb5_unparse_name(context, principal, &set_password_on_princ) != 0) {
331 krb5_free_principal(context, principal);
332 return kpasswdd_make_error_reply(kdc, mem_ctx,
333 KRB5_KPASSWD_MALFORMED,
334 "krb5_unparse_name failed!",
338 krb5_free_principal(context, principal);
340 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, session_info);
342 return kpasswdd_make_error_reply(kdc, mem_ctx,
343 KRB5_KPASSWD_HARDERROR,
344 "Unable to open database!",
348 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
349 session_info->server_info->domain_name,
350 session_info->server_info->account_name,
351 dom_sid_string(mem_ctx, session_info->security_token->user_sid),
352 set_password_on_princ));
353 ret = ldb_transaction_start(samdb);
355 status = NT_STATUS_TRANSACTION_ABORTED;
356 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
358 SAM_PWD_CHANGE_NO_ERROR,
363 if (service_principal_name) {
364 status = crack_service_principal_name(samdb, mem_ctx,
365 set_password_on_princ,
366 &set_password_on_dn, NULL);
368 status = crack_user_principal_name(samdb, mem_ctx,
369 set_password_on_princ,
370 &set_password_on_dn, NULL);
372 free(set_password_on_princ);
373 if (!NT_STATUS_IS_OK(status)) {
374 ldb_transaction_cancel(samdb);
375 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
377 SAM_PWD_CHANGE_NO_ERROR,
382 msg = ldb_msg_new(mem_ctx);
384 ldb_transaction_cancel(samdb);
385 status = NT_STATUS_NO_MEMORY;
387 msg->dn = ldb_dn_copy(msg, set_password_on_dn);
389 status = NT_STATUS_NO_MEMORY;
393 if (NT_STATUS_IS_OK(status)) {
394 /* Admin password set */
395 status = samdb_set_password(samdb, mem_ctx,
396 set_password_on_dn, NULL,
397 msg, &password, NULL, NULL,
398 false, /* this is not a user password change */
399 &reject_reason, &dominfo);
402 if (NT_STATUS_IS_OK(status)) {
403 /* modify the samdb record */
404 ret = dsdb_replace(samdb, msg, 0);
406 DEBUG(2,("Failed to modify record to set password on %s: %s\n",
407 ldb_dn_get_linearized(msg->dn),
408 ldb_errstring(samdb)));
409 status = NT_STATUS_ACCESS_DENIED;
412 if (NT_STATUS_IS_OK(status)) {
413 ret = ldb_transaction_commit(samdb);
415 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
416 ldb_dn_get_linearized(msg->dn),
417 ldb_errstring(samdb)));
418 status = NT_STATUS_TRANSACTION_ABORTED;
421 ldb_transaction_cancel(samdb);
423 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
430 return kpasswdd_make_error_reply(kdc, mem_ctx,
431 KRB5_KPASSWD_BAD_VERSION,
432 talloc_asprintf(mem_ctx,
433 "Protocol version %u not supported",
440 bool kpasswdd_process(struct kdc_server *kdc,
444 struct tsocket_address *peer_addr,
445 struct tsocket_address *my_addr,
449 const uint16_t header_len = 6;
452 uint16_t krb_priv_len;
455 DATA_BLOB ap_req, krb_priv_req;
456 DATA_BLOB krb_priv_rep = data_blob(NULL, 0);
457 DATA_BLOB ap_rep = data_blob(NULL, 0);
458 DATA_BLOB kpasswd_req, kpasswd_rep;
459 struct cli_credentials *server_credentials;
460 struct gensec_security *gensec_security;
461 TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
469 /* Be parinoid. We need to ensure we don't just let the
470 * caller lead us into a buffer overflow */
471 if (input->length <= header_len) {
472 talloc_free(tmp_ctx);
476 len = RSVAL(input->data, 0);
477 if (input->length != len) {
478 talloc_free(tmp_ctx);
482 /* There are two different versions of this protocol so far,
483 * plus others in the standards pipe. Fortunetly they all
484 * take a very similar framing */
485 version = RSVAL(input->data, 2);
486 ap_req_len = RSVAL(input->data, 4);
487 if ((ap_req_len >= len) || (ap_req_len + header_len) >= len) {
488 talloc_free(tmp_ctx);
492 krb_priv_len = len - ap_req_len;
493 ap_req = data_blob_const(&input->data[header_len], ap_req_len);
494 krb_priv_req = data_blob_const(&input->data[header_len + ap_req_len], krb_priv_len);
496 server_credentials = cli_credentials_init(tmp_ctx);
497 if (!server_credentials) {
498 DEBUG(1, ("Failed to init server credentials\n"));
502 /* We want the credentials subsystem to use the krb5 context
503 * we already have, rather than a new context */
504 cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
505 cli_credentials_set_conf(server_credentials, kdc->task->lp_ctx);
507 keytab_name = talloc_asprintf(server_credentials, "HDB:samba4&%p", kdc->base_ctx);
509 cli_credentials_set_username(server_credentials, "kadmin/changepw", CRED_SPECIFIED);
510 ret = cli_credentials_set_keytab_name(server_credentials, kdc->task->event_ctx, kdc->task->lp_ctx, keytab_name, CRED_SPECIFIED);
512 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
513 KRB5_KPASSWD_HARDERROR,
514 talloc_asprintf(mem_ctx,
515 "Failed to obtain server credentials for kadmin/changepw: %s\n",
516 nt_errstr(nt_status)),
522 talloc_free(tmp_ctx);
526 /* We don't strictly need to call this wrapper, and could call
527 * gensec_server_start directly, as we have no need for NTLM
528 * and we have a PAC, but this ensures that the wrapper can be
529 * safely extended for other helpful things in future */
530 nt_status = samba_server_gensec_start(tmp_ctx, kdc->task->event_ctx,
536 if (!NT_STATUS_IS_OK(nt_status)) {
537 talloc_free(tmp_ctx);
541 /* The kerberos PRIV packets include these addresses. MIT
542 * clients check that they are present */
544 /* Skip this part for now, it breaks with a NetAPP filer and
545 * in any case where the client address is behind NAT. If
546 * older MIT clients need this, we might have to insert more
549 nt_status = gensec_set_local_address(gensec_security, peer_addr);
550 if (!NT_STATUS_IS_OK(nt_status)) {
551 talloc_free(tmp_ctx);
556 nt_status = gensec_set_local_address(gensec_security, my_addr);
557 if (!NT_STATUS_IS_OK(nt_status)) {
558 talloc_free(tmp_ctx);
562 /* We want the GENSEC wrap calls to generate PRIV tokens */
563 gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
565 nt_status = gensec_start_mech_by_name(gensec_security, "krb5");
566 if (!NT_STATUS_IS_OK(nt_status)) {
567 talloc_free(tmp_ctx);
571 /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
572 nt_status = gensec_update(gensec_security, tmp_ctx, ap_req, &ap_rep);
573 if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
575 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
576 KRB5_KPASSWD_HARDERROR,
577 talloc_asprintf(mem_ctx,
578 "gensec_update failed: %s",
579 nt_errstr(nt_status)),
585 talloc_free(tmp_ctx);
589 /* Extract the data from the KRB-PRIV half of the message */
590 nt_status = gensec_unwrap(gensec_security, tmp_ctx, &krb_priv_req, &kpasswd_req);
591 if (!NT_STATUS_IS_OK(nt_status)) {
592 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
593 KRB5_KPASSWD_HARDERROR,
594 talloc_asprintf(mem_ctx,
595 "gensec_unwrap failed: %s",
596 nt_errstr(nt_status)),
602 talloc_free(tmp_ctx);
606 /* Figure out something to do with it (probably changing a password...) */
607 ret = kpasswd_process_request(kdc, tmp_ctx,
610 &kpasswd_req, &kpasswd_rep);
616 /* And wrap up the reply: This ensures that the error message
617 * or success can be verified by the client */
618 nt_status = gensec_wrap(gensec_security, tmp_ctx,
619 &kpasswd_rep, &krb_priv_rep);
620 if (!NT_STATUS_IS_OK(nt_status)) {
621 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
622 KRB5_KPASSWD_HARDERROR,
623 talloc_asprintf(mem_ctx,
624 "gensec_wrap failed: %s",
625 nt_errstr(nt_status)),
631 talloc_free(tmp_ctx);
636 *reply = data_blob_talloc(mem_ctx, NULL, krb_priv_rep.length + ap_rep.length + header_len);
641 RSSVAL(reply->data, 0, reply->length);
642 RSSVAL(reply->data, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
643 RSSVAL(reply->data, 4, ap_rep.length);
644 memcpy(reply->data + header_len,
647 memcpy(reply->data + header_len + ap_rep.length,
649 krb_priv_rep.length);
651 talloc_free(tmp_ctx);