s3: Paranoia in smbsock_connect_state_destructor
[Samba.git] / source4 / kdc / kpasswdd.c
blob117cab095db26c24ae269cae3e38cafefa154b27
1 /*
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/>.
23 #include "includes.h"
24 #include "smbd/service_task.h"
25 #include "auth/gensec/gensec.h"
26 #include "auth/credentials/credentials.h"
27 #include "auth/auth.h"
28 #include "dsdb/samdb/samdb.h"
29 #include "../lib/util/util_ldb.h"
30 #include "libcli/security/security.h"
31 #include "param/param.h"
32 #include "kdc/kdc-glue.h"
34 /* Return true if there is a valid error packet formed in the error_blob */
35 static bool kpasswdd_make_error_reply(struct kdc_server *kdc,
36 TALLOC_CTX *mem_ctx,
37 uint16_t result_code,
38 const char *error_string,
39 DATA_BLOB *error_blob)
41 char *error_string_utf8;
42 size_t len;
44 DEBUG(result_code ? 3 : 10, ("kpasswdd: %s\n", error_string));
46 if (!push_utf8_talloc(mem_ctx, &error_string_utf8, error_string, &len)) {
47 return false;
50 *error_blob = data_blob_talloc(mem_ctx, NULL, 2 + len + 1);
51 if (!error_blob->data) {
52 return false;
54 RSSVAL(error_blob->data, 0, result_code);
55 memcpy(error_blob->data + 2, error_string_utf8, len + 1);
56 return true;
59 /* Return true if there is a valid error packet formed in the error_blob */
60 static bool kpasswdd_make_unauth_error_reply(struct kdc_server *kdc,
61 TALLOC_CTX *mem_ctx,
62 uint16_t result_code,
63 const char *error_string,
64 DATA_BLOB *error_blob)
66 bool ret;
67 int kret;
68 DATA_BLOB error_bytes;
69 krb5_data k5_error_bytes, k5_error_blob;
70 ret = kpasswdd_make_error_reply(kdc, mem_ctx, result_code, error_string,
71 &error_bytes);
72 if (!ret) {
73 return false;
75 k5_error_bytes.data = error_bytes.data;
76 k5_error_bytes.length = error_bytes.length;
77 kret = krb5_mk_error(kdc->smb_krb5_context->krb5_context,
78 result_code, NULL, &k5_error_bytes,
79 NULL, NULL, NULL, NULL, &k5_error_blob);
80 if (kret) {
81 return false;
83 *error_blob = data_blob_talloc(mem_ctx, k5_error_blob.data, k5_error_blob.length);
84 krb5_data_free(&k5_error_blob);
85 if (!error_blob->data) {
86 return false;
88 return true;
91 static bool kpasswd_make_pwchange_reply(struct kdc_server *kdc,
92 TALLOC_CTX *mem_ctx,
93 NTSTATUS status,
94 enum samPwdChangeReason reject_reason,
95 struct samr_DomInfo1 *dominfo,
96 DATA_BLOB *error_blob)
98 if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_USER)) {
99 return kpasswdd_make_error_reply(kdc, mem_ctx,
100 KRB5_KPASSWD_ACCESSDENIED,
101 "No such user when changing password",
102 error_blob);
104 if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
105 return kpasswdd_make_error_reply(kdc, mem_ctx,
106 KRB5_KPASSWD_ACCESSDENIED,
107 "Not permitted to change password",
108 error_blob);
110 if (dominfo && NT_STATUS_EQUAL(status, NT_STATUS_PASSWORD_RESTRICTION)) {
111 const char *reject_string;
112 switch (reject_reason) {
113 case SAM_PWD_CHANGE_PASSWORD_TOO_SHORT:
114 reject_string = talloc_asprintf(mem_ctx, "Password too short, password must be at least %d characters long",
115 dominfo->min_password_length);
116 break;
117 case SAM_PWD_CHANGE_NOT_COMPLEX:
118 reject_string = "Password does not meet complexity requirements";
119 break;
120 case SAM_PWD_CHANGE_PWD_IN_HISTORY:
121 reject_string = "Password is already in password history";
122 break;
123 default:
124 reject_string = talloc_asprintf(mem_ctx, "Password must be at least %d characters long, and cannot match any of your %d previous passwords",
125 dominfo->min_password_length, dominfo->password_history_length);
126 break;
128 return kpasswdd_make_error_reply(kdc, mem_ctx,
129 KRB5_KPASSWD_SOFTERROR,
130 reject_string,
131 error_blob);
133 if (!NT_STATUS_IS_OK(status)) {
134 return kpasswdd_make_error_reply(kdc, mem_ctx,
135 KRB5_KPASSWD_HARDERROR,
136 talloc_asprintf(mem_ctx, "failed to set password: %s", nt_errstr(status)),
137 error_blob);
140 return kpasswdd_make_error_reply(kdc, mem_ctx, KRB5_KPASSWD_SUCCESS,
141 "Password changed",
142 error_blob);
146 A user password change
148 Return true if there is a valid error packet (or success) formed in
149 the error_blob
151 static bool kpasswdd_change_password(struct kdc_server *kdc,
152 TALLOC_CTX *mem_ctx,
153 struct auth_session_info *session_info,
154 const DATA_BLOB *password,
155 DATA_BLOB *reply)
157 NTSTATUS status;
158 enum samPwdChangeReason reject_reason;
159 struct samr_DomInfo1 *dominfo;
160 struct samr_Password *oldLmHash, *oldNtHash;
161 struct ldb_context *samdb;
162 const char * const attrs[] = { "dBCSPwd", "unicodePwd", NULL };
163 struct ldb_message **res;
164 int ret;
166 /* Fetch the old hashes to get the old password in order to perform
167 * the password change operation. Naturally it would be much better to
168 * have a password hash from an authentication around but this doesn't
169 * seem to be the case here. */
170 ret = gendb_search(kdc->samdb, mem_ctx, NULL, &res, attrs,
171 "(&(objectClass=user)(sAMAccountName=%s))",
172 session_info->info->account_name);
173 if (ret != 1) {
174 return kpasswdd_make_error_reply(kdc, mem_ctx,
175 KRB5_KPASSWD_ACCESSDENIED,
176 "No such user when changing password",
177 reply);
180 status = samdb_result_passwords(mem_ctx, kdc->task->lp_ctx, res[0],
181 &oldLmHash, &oldNtHash);
182 if (!NT_STATUS_IS_OK(status)) {
183 return kpasswdd_make_error_reply(kdc, mem_ctx,
184 KRB5_KPASSWD_ACCESSDENIED,
185 "Not permitted to change password",
186 reply);
189 /* Start a SAM with user privileges for the password change */
190 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx,
191 session_info, 0);
192 if (!samdb) {
193 return kpasswdd_make_error_reply(kdc, mem_ctx,
194 KRB5_KPASSWD_HARDERROR,
195 "Failed to open samdb",
196 reply);
199 DEBUG(3, ("Changing password of %s\\%s (%s)\n",
200 session_info->info->domain_name,
201 session_info->info->account_name,
202 dom_sid_string(mem_ctx, &session_info->security_token->sids[PRIMARY_USER_SID_INDEX])));
204 /* Performs the password change */
205 status = samdb_set_password_sid(samdb, mem_ctx,
206 &session_info->security_token->sids[PRIMARY_USER_SID_INDEX],
207 password, NULL, NULL,
208 oldLmHash, oldNtHash, /* this is a user password change */
209 &reject_reason,
210 &dominfo);
211 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
212 status,
213 reject_reason,
214 dominfo,
215 reply);
219 static bool kpasswd_process_request(struct kdc_server *kdc,
220 TALLOC_CTX *mem_ctx,
221 struct gensec_security *gensec_security,
222 uint16_t version,
223 DATA_BLOB *input,
224 DATA_BLOB *reply)
226 struct auth_session_info *session_info;
227 size_t pw_len;
229 if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security,
230 &session_info))) {
231 return kpasswdd_make_error_reply(kdc, mem_ctx,
232 KRB5_KPASSWD_HARDERROR,
233 "gensec_session_info failed!",
234 reply);
237 switch (version) {
238 case KRB5_KPASSWD_VERS_CHANGEPW:
240 DATA_BLOB password;
241 if (!convert_string_talloc_convenience(mem_ctx, lpcfg_iconv_convenience(kdc->task->lp_ctx),
242 CH_UTF8, CH_UTF16,
243 (const char *)input->data,
244 input->length,
245 (void **)&password.data, &pw_len, false)) {
246 return false;
248 password.length = pw_len;
250 return kpasswdd_change_password(kdc, mem_ctx, session_info,
251 &password, reply);
253 case KRB5_KPASSWD_VERS_SETPW:
255 NTSTATUS status;
256 enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
257 struct samr_DomInfo1 *dominfo = NULL;
258 struct ldb_context *samdb;
259 krb5_context context = kdc->smb_krb5_context->krb5_context;
261 ChangePasswdDataMS chpw;
262 DATA_BLOB password;
264 krb5_principal principal;
265 char *set_password_on_princ;
266 struct ldb_dn *set_password_on_dn;
267 bool service_principal_name = false;
269 size_t len;
270 int ret;
272 ret = decode_ChangePasswdDataMS(input->data, input->length,
273 &chpw, &len);
274 if (ret) {
275 return kpasswdd_make_error_reply(kdc, mem_ctx,
276 KRB5_KPASSWD_MALFORMED,
277 "failed to decode password change structure",
278 reply);
281 if (!convert_string_talloc_convenience(mem_ctx, lpcfg_iconv_convenience(kdc->task->lp_ctx),
282 CH_UTF8, CH_UTF16,
283 (const char *)chpw.newpasswd.data,
284 chpw.newpasswd.length,
285 (void **)&password.data, &pw_len, false)) {
286 free_ChangePasswdDataMS(&chpw);
287 return false;
290 password.length = pw_len;
292 if ((chpw.targname && !chpw.targrealm)
293 || (!chpw.targname && chpw.targrealm)) {
294 free_ChangePasswdDataMS(&chpw);
295 return kpasswdd_make_error_reply(kdc, mem_ctx,
296 KRB5_KPASSWD_MALFORMED,
297 "Realm and principal must be both present, or neither present",
298 reply);
300 if (chpw.targname && chpw.targrealm) {
301 ret = krb5_build_principal_ext(kdc->smb_krb5_context->krb5_context,
302 &principal,
303 strlen(*chpw.targrealm),
304 *chpw.targrealm, 0);
305 if (ret) {
306 free_ChangePasswdDataMS(&chpw);
307 return kpasswdd_make_error_reply(kdc, mem_ctx,
308 KRB5_KPASSWD_MALFORMED,
309 "failed to get principal",
310 reply);
312 if (copy_PrincipalName(chpw.targname, &principal->name)) {
313 free_ChangePasswdDataMS(&chpw);
314 krb5_free_principal(context, principal);
315 return kpasswdd_make_error_reply(kdc, mem_ctx,
316 KRB5_KPASSWD_MALFORMED,
317 "failed to extract principal to set",
318 reply);
320 } else {
321 free_ChangePasswdDataMS(&chpw);
322 return kpasswdd_change_password(kdc, mem_ctx, session_info,
323 &password, reply);
325 free_ChangePasswdDataMS(&chpw);
327 if (principal->name.name_string.len >= 2) {
328 service_principal_name = true;
330 /* We use this, rather than 'no realm' flag,
331 * as we don't want to accept a password
332 * change on a principal from another realm */
334 if (krb5_unparse_name_short(context, principal, &set_password_on_princ) != 0) {
335 krb5_free_principal(context, principal);
336 return kpasswdd_make_error_reply(kdc, mem_ctx,
337 KRB5_KPASSWD_MALFORMED,
338 "krb5_unparse_name failed!",
339 reply);
341 } else {
342 if (krb5_unparse_name(context, principal, &set_password_on_princ) != 0) {
343 krb5_free_principal(context, principal);
344 return kpasswdd_make_error_reply(kdc, mem_ctx,
345 KRB5_KPASSWD_MALFORMED,
346 "krb5_unparse_name failed!",
347 reply);
350 krb5_free_principal(context, principal);
352 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, session_info, 0);
353 if (!samdb) {
354 free(set_password_on_princ);
355 return kpasswdd_make_error_reply(kdc, mem_ctx,
356 KRB5_KPASSWD_HARDERROR,
357 "Unable to open database!",
358 reply);
361 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
362 session_info->info->domain_name,
363 session_info->info->account_name,
364 dom_sid_string(mem_ctx, &session_info->security_token->sids[PRIMARY_USER_SID_INDEX]),
365 set_password_on_princ));
366 ret = ldb_transaction_start(samdb);
367 if (ret != LDB_SUCCESS) {
368 free(set_password_on_princ);
369 status = NT_STATUS_TRANSACTION_ABORTED;
370 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
371 status,
372 SAM_PWD_CHANGE_NO_ERROR,
373 NULL,
374 reply);
377 if (service_principal_name) {
378 status = crack_service_principal_name(samdb, mem_ctx,
379 set_password_on_princ,
380 &set_password_on_dn, NULL);
381 } else {
382 status = crack_user_principal_name(samdb, mem_ctx,
383 set_password_on_princ,
384 &set_password_on_dn, NULL);
386 free(set_password_on_princ);
387 if (!NT_STATUS_IS_OK(status)) {
388 ldb_transaction_cancel(samdb);
389 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
390 status,
391 SAM_PWD_CHANGE_NO_ERROR,
392 NULL,
393 reply);
396 if (NT_STATUS_IS_OK(status)) {
397 /* Admin password set */
398 status = samdb_set_password(samdb, mem_ctx,
399 set_password_on_dn, NULL,
400 &password, NULL, NULL,
401 NULL, NULL, /* this is not a user password change */
402 &reject_reason, &dominfo);
405 if (NT_STATUS_IS_OK(status)) {
406 ret = ldb_transaction_commit(samdb);
407 if (ret != LDB_SUCCESS) {
408 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
409 ldb_dn_get_linearized(set_password_on_dn),
410 ldb_errstring(samdb)));
411 status = NT_STATUS_TRANSACTION_ABORTED;
413 } else {
414 ldb_transaction_cancel(samdb);
416 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
417 status,
418 reject_reason,
419 dominfo,
420 reply);
422 default:
423 return kpasswdd_make_error_reply(kdc, mem_ctx,
424 KRB5_KPASSWD_BAD_VERSION,
425 talloc_asprintf(mem_ctx,
426 "Protocol version %u not supported",
427 version),
428 reply);
432 enum kdc_process_ret kpasswdd_process(struct kdc_server *kdc,
433 TALLOC_CTX *mem_ctx,
434 DATA_BLOB *input,
435 DATA_BLOB *reply,
436 struct tsocket_address *peer_addr,
437 struct tsocket_address *my_addr,
438 int datagram_reply)
440 bool ret;
441 const uint16_t header_len = 6;
442 uint16_t len;
443 uint16_t ap_req_len;
444 uint16_t krb_priv_len;
445 uint16_t version;
446 NTSTATUS nt_status;
447 DATA_BLOB ap_req, krb_priv_req;
448 DATA_BLOB krb_priv_rep = data_blob(NULL, 0);
449 DATA_BLOB ap_rep = data_blob(NULL, 0);
450 DATA_BLOB kpasswd_req, kpasswd_rep;
451 struct cli_credentials *server_credentials;
452 struct gensec_security *gensec_security;
453 TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
455 char *keytab_name;
457 if (!tmp_ctx) {
458 return KDC_PROCESS_FAILED;
461 if (kdc->am_rodc) {
462 talloc_free(tmp_ctx);
463 return KDC_PROCESS_PROXY;
466 /* Be parinoid. We need to ensure we don't just let the
467 * caller lead us into a buffer overflow */
468 if (input->length <= header_len) {
469 talloc_free(tmp_ctx);
470 return KDC_PROCESS_FAILED;
473 len = RSVAL(input->data, 0);
474 if (input->length != len) {
475 talloc_free(tmp_ctx);
476 return KDC_PROCESS_FAILED;
479 /* There are two different versions of this protocol so far,
480 * plus others in the standards pipe. Fortunetly they all
481 * take a very similar framing */
482 version = RSVAL(input->data, 2);
483 ap_req_len = RSVAL(input->data, 4);
484 if ((ap_req_len >= len) || (ap_req_len + header_len) >= len) {
485 talloc_free(tmp_ctx);
486 return KDC_PROCESS_FAILED;
489 krb_priv_len = len - ap_req_len;
490 ap_req = data_blob_const(&input->data[header_len], ap_req_len);
491 krb_priv_req = data_blob_const(&input->data[header_len + ap_req_len], krb_priv_len);
493 server_credentials = cli_credentials_init(tmp_ctx);
494 if (!server_credentials) {
495 DEBUG(1, ("Failed to init server credentials\n"));
496 talloc_free(tmp_ctx);
497 return KDC_PROCESS_FAILED;
500 /* We want the credentials subsystem to use the krb5 context
501 * we already have, rather than a new context */
502 cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
503 cli_credentials_set_conf(server_credentials, kdc->task->lp_ctx);
505 keytab_name = talloc_asprintf(server_credentials, "HDB:samba4&%p", kdc->base_ctx);
507 cli_credentials_set_username(server_credentials, "kadmin/changepw", CRED_SPECIFIED);
508 ret = cli_credentials_set_keytab_name(server_credentials, kdc->task->lp_ctx, keytab_name, CRED_SPECIFIED);
509 if (ret != 0) {
510 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
511 KRB5_KPASSWD_HARDERROR,
512 talloc_asprintf(mem_ctx,
513 "Failed to obtain server credentials for kadmin/changepw!"),
514 &krb_priv_rep);
515 ap_rep.length = 0;
516 if (ret) {
517 goto reply;
519 talloc_free(tmp_ctx);
520 return ret;
523 /* We don't strictly need to call this wrapper, and could call
524 * gensec_server_start directly, as we have no need for NTLM
525 * and we have a PAC, but this ensures that the wrapper can be
526 * safely extended for other helpful things in future */
527 nt_status = samba_server_gensec_start(tmp_ctx, kdc->task->event_ctx,
528 kdc->task->msg_ctx,
529 kdc->task->lp_ctx,
530 server_credentials,
531 "kpasswd",
532 &gensec_security);
533 if (!NT_STATUS_IS_OK(nt_status)) {
534 talloc_free(tmp_ctx);
535 return KDC_PROCESS_FAILED;
538 /* The kerberos PRIV packets include these addresses. MIT
539 * clients check that they are present */
540 #if 0
541 /* Skip this part for now, it breaks with a NetAPP filer and
542 * in any case where the client address is behind NAT. If
543 * older MIT clients need this, we might have to insert more
544 * complex code */
546 nt_status = gensec_set_local_address(gensec_security, peer_addr);
547 if (!NT_STATUS_IS_OK(nt_status)) {
548 talloc_free(tmp_ctx);
549 return KDC_PROCESS_FAILED;
551 #endif
553 nt_status = gensec_set_local_address(gensec_security, my_addr);
554 if (!NT_STATUS_IS_OK(nt_status)) {
555 talloc_free(tmp_ctx);
556 return KDC_PROCESS_FAILED;
559 /* We want the GENSEC wrap calls to generate PRIV tokens */
560 gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
562 nt_status = gensec_start_mech_by_name(gensec_security, "krb5");
563 if (!NT_STATUS_IS_OK(nt_status)) {
564 talloc_free(tmp_ctx);
565 return KDC_PROCESS_FAILED;
568 /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
569 nt_status = gensec_update(gensec_security, tmp_ctx, ap_req, &ap_rep);
570 if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
572 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
573 KRB5_KPASSWD_HARDERROR,
574 talloc_asprintf(mem_ctx,
575 "gensec_update failed: %s",
576 nt_errstr(nt_status)),
577 &krb_priv_rep);
578 ap_rep.length = 0;
579 if (ret) {
580 goto reply;
582 talloc_free(tmp_ctx);
583 return KDC_PROCESS_FAILED;
586 /* Extract the data from the KRB-PRIV half of the message */
587 nt_status = gensec_unwrap(gensec_security, tmp_ctx, &krb_priv_req, &kpasswd_req);
588 if (!NT_STATUS_IS_OK(nt_status)) {
589 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
590 KRB5_KPASSWD_HARDERROR,
591 talloc_asprintf(mem_ctx,
592 "gensec_unwrap failed: %s",
593 nt_errstr(nt_status)),
594 &krb_priv_rep);
595 ap_rep.length = 0;
596 if (ret) {
597 goto reply;
599 talloc_free(tmp_ctx);
600 return KDC_PROCESS_FAILED;
603 /* Figure out something to do with it (probably changing a password...) */
604 ret = kpasswd_process_request(kdc, tmp_ctx,
605 gensec_security,
606 version,
607 &kpasswd_req, &kpasswd_rep);
608 if (!ret) {
609 /* Argh! */
610 talloc_free(tmp_ctx);
611 return KDC_PROCESS_FAILED;
614 /* And wrap up the reply: This ensures that the error message
615 * or success can be verified by the client */
616 nt_status = gensec_wrap(gensec_security, tmp_ctx,
617 &kpasswd_rep, &krb_priv_rep);
618 if (!NT_STATUS_IS_OK(nt_status)) {
619 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
620 KRB5_KPASSWD_HARDERROR,
621 talloc_asprintf(mem_ctx,
622 "gensec_wrap failed: %s",
623 nt_errstr(nt_status)),
624 &krb_priv_rep);
625 ap_rep.length = 0;
626 if (ret) {
627 goto reply;
629 talloc_free(tmp_ctx);
630 return KDC_PROCESS_FAILED;
633 reply:
634 *reply = data_blob_talloc(mem_ctx, NULL, krb_priv_rep.length + ap_rep.length + header_len);
635 if (!reply->data) {
636 talloc_free(tmp_ctx);
637 return KDC_PROCESS_FAILED;
640 RSSVAL(reply->data, 0, reply->length);
641 RSSVAL(reply->data, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
642 RSSVAL(reply->data, 4, ap_rep.length);
643 memcpy(reply->data + header_len,
644 ap_rep.data,
645 ap_rep.length);
646 memcpy(reply->data + header_len + ap_rep.length,
647 krb_priv_rep.data,
648 krb_priv_rep.length);
650 talloc_free(tmp_ctx);
651 return KDC_PROCESS_OK;