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s3: Cache results of finding printer names
[Samba.git] / source4 / kdc / kpasswdd.c
blob9c02ac3465e35cb3885b34489f4193632d5dcea1
1 /*
2 Unix SMB/CIFS implementation.
3
4 kpasswd Server implementation
5
6 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
7 Copyright (C) Andrew Tridgell 2005
8
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.
13
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.
18
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/>.
21 */
22
23 #include "includes.h"
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"
40 #include "kdc/kdc.h"
41
42 /* TODO: remove all SAMBA4_INTERNAL_HEIMDAL stuff from this file */
43 #ifdef SAMBA4_INTERNAL_HEIMDAL
44 #include "heimdal_build/kpasswdd-glue.h"
45 #endif
46
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,
49 TALLOC_CTX *mem_ctx,
50 uint16_t result_code,
51 const char *error_string,
52 DATA_BLOB *error_blob)
53 {
54 char *error_string_utf8;
55 size_t len;
56
57 DEBUG(result_code ? 3 : 10, ("kpasswdd: %s\n", error_string));
58
59 if (!push_utf8_talloc(mem_ctx, &error_string_utf8, error_string, &len)) {
60 return false;
61 }
62
63 *error_blob = data_blob_talloc(mem_ctx, NULL, 2 + len + 1);
64 if (!error_blob->data) {
65 return false;
66 }
67 RSSVAL(error_blob->data, 0, result_code);
68 memcpy(error_blob->data + 2, error_string_utf8, len + 1);
69 return true;
70 }
71
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,
74 TALLOC_CTX *mem_ctx,
75 uint16_t result_code,
76 const char *error_string,
77 DATA_BLOB *error_blob)
78 {
79 bool ret;
80 int kret;
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,
84 &error_bytes);
85 if (!ret) {
86 return false;
87 }
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);
93 if (kret) {
94 return false;
95 }
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) {
99 return false;
100 }
101 return true;
102 }
103
104 static bool kpasswd_make_pwchange_reply(struct kdc_server *kdc,
105 TALLOC_CTX *mem_ctx,
106 NTSTATUS status,
107 enum samPwdChangeReason reject_reason,
108 struct samr_DomInfo1 *dominfo,
109 DATA_BLOB *error_blob)
110 {
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",
115 error_blob);
116 }
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",
121 error_blob);
122 }
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);
129 break;
130 case SAM_PWD_CHANGE_NOT_COMPLEX:
131 reject_string = "Password does not meet complexity requirements";
132 break;
133 case SAM_PWD_CHANGE_PWD_IN_HISTORY:
134 reject_string = "Password is already in password history";
135 break;
136 default:
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);
139 break;
140 }
141 return kpasswdd_make_error_reply(kdc, mem_ctx,
142 KRB5_KPASSWD_SOFTERROR,
143 reject_string,
144 error_blob);
145 }
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)),
150 error_blob);
151
152 }
153 return kpasswdd_make_error_reply(kdc, mem_ctx, KRB5_KPASSWD_SUCCESS,
154 "Password changed",
155 error_blob);
156 }
157
158 /*
159 A user password change
160
161 Return true if there is a valid error packet (or success) formed in
162 the error_blob
163 */
164 static bool kpasswdd_change_password(struct kdc_server *kdc,
165 TALLOC_CTX *mem_ctx,
166 struct auth_session_info *session_info,
167 const DATA_BLOB *password,
168 DATA_BLOB *reply)
169 {
170 NTSTATUS status;
171 enum samPwdChangeReason reject_reason;
172 struct samr_DomInfo1 *dominfo;
173 struct ldb_context *samdb;
174
175 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, system_session(kdc->task->lp_ctx));
176 if (!samdb) {
177 return kpasswdd_make_error_reply(kdc, mem_ctx,
178 KRB5_KPASSWD_HARDERROR,
179 "Failed to open samdb",
180 reply);
181 }
182
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)));
187
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 */
193 &reject_reason,
194 &dominfo);
195 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
196 status,
197 reject_reason,
198 dominfo,
199 reply);
200
201 }
202
203 static bool kpasswd_process_request(struct kdc_server *kdc,
204 TALLOC_CTX *mem_ctx,
205 struct gensec_security *gensec_security,
206 uint16_t version,
207 DATA_BLOB *input,
208 DATA_BLOB *reply)
209 {
210 struct auth_session_info *session_info;
211 size_t pw_len;
212
213 if (!NT_STATUS_IS_OK(gensec_session_info(gensec_security,
214 &session_info))) {
215 return kpasswdd_make_error_reply(kdc, mem_ctx,
216 KRB5_KPASSWD_HARDERROR,
217 "gensec_session_info failed!",
218 reply);
219 }
220
221 switch (version) {
222 case KRB5_KPASSWD_VERS_CHANGEPW:
223 {
224 DATA_BLOB password;
225 if (!convert_string_talloc_convenience(mem_ctx, lpcfg_iconv_convenience(kdc->task->lp_ctx),
226 CH_UTF8, CH_UTF16,
227 (const char *)input->data,
228 input->length,
229 (void **)&password.data, &pw_len, false)) {
230 return false;
231 }
232 password.length = pw_len;
233
234 return kpasswdd_change_password(kdc, mem_ctx, session_info,
235 &password, reply);
236 }
237 case KRB5_KPASSWD_VERS_SETPW:
238 {
239 NTSTATUS status;
240 enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
241 struct samr_DomInfo1 *dominfo = NULL;
242 struct ldb_context *samdb;
243 krb5_context context = kdc->smb_krb5_context->krb5_context;
244
245 ChangePasswdDataMS chpw;
246 DATA_BLOB password;
247
248 krb5_principal principal;
249 char *set_password_on_princ;
250 struct ldb_dn *set_password_on_dn;
251 bool service_principal_name = false;
252
253 size_t len;
254 int ret;
255
256 ret = decode_ChangePasswdDataMS(input->data, input->length,
257 &chpw, &len);
258 if (ret) {
259 return kpasswdd_make_error_reply(kdc, mem_ctx,
260 KRB5_KPASSWD_MALFORMED,
261 "failed to decode password change structure",
262 reply);
263 }
264
265 if (!convert_string_talloc_convenience(mem_ctx, lpcfg_iconv_convenience(kdc->task->lp_ctx),
266 CH_UTF8, CH_UTF16,
267 (const char *)chpw.newpasswd.data,
268 chpw.newpasswd.length,
269 (void **)&password.data, &pw_len, false)) {
270 free_ChangePasswdDataMS(&chpw);
271 return false;
272 }
273
274 password.length = pw_len;
275
276 if ((chpw.targname && !chpw.targrealm)
277 || (!chpw.targname && chpw.targrealm)) {
278 return kpasswdd_make_error_reply(kdc, mem_ctx,
279 KRB5_KPASSWD_MALFORMED,
280 "Realm and principal must be both present, or neither present",
281 reply);
282 }
283 if (chpw.targname && chpw.targrealm) {
284 #ifdef SAMBA4_INTERNAL_HEIMDAL
285 if (_krb5_principalname2krb5_principal(kdc->smb_krb5_context->krb5_context,
286 &principal, *chpw.targname,
287 *chpw.targrealm) != 0) {
288 free_ChangePasswdDataMS(&chpw);
289 return kpasswdd_make_error_reply(kdc, mem_ctx,
290 KRB5_KPASSWD_MALFORMED,
291 "failed to extract principal to set",
292 reply);
293
294 }
295 #else /* SAMBA4_INTERNAL_HEIMDAL */
296 return kpasswdd_make_error_reply(kdc, mem_ctx,
297 KRB5_KPASSWD_BAD_VERSION,
298 "Operation Not Implemented",
299 reply);
300 #endif /* SAMBA4_INTERNAL_HEIMDAL */
301 } else {
302 free_ChangePasswdDataMS(&chpw);
303 return kpasswdd_change_password(kdc, mem_ctx, session_info,
304 &password, reply);
305 }
306 free_ChangePasswdDataMS(&chpw);
307
308 if (principal->name.name_string.len >= 2) {
309 service_principal_name = true;
310
311 /* We use this, rather than 'no realm' flag,
312 * as we don't want to accept a password
313 * change on a principal from another realm */
314
315 if (krb5_unparse_name_short(context, principal, &set_password_on_princ) != 0) {
316 krb5_free_principal(context, principal);
317 return kpasswdd_make_error_reply(kdc, mem_ctx,
318 KRB5_KPASSWD_MALFORMED,
319 "krb5_unparse_name failed!",
320 reply);
321 }
322 } else {
323 if (krb5_unparse_name(context, principal, &set_password_on_princ) != 0) {
324 krb5_free_principal(context, principal);
325 return kpasswdd_make_error_reply(kdc, mem_ctx,
326 KRB5_KPASSWD_MALFORMED,
327 "krb5_unparse_name failed!",
328 reply);
329 }
330 }
331 krb5_free_principal(context, principal);
332
333 samdb = samdb_connect(mem_ctx, kdc->task->event_ctx, kdc->task->lp_ctx, session_info);
334 if (!samdb) {
335 return kpasswdd_make_error_reply(kdc, mem_ctx,
336 KRB5_KPASSWD_HARDERROR,
337 "Unable to open database!",
338 reply);
339 }
340
341 DEBUG(3, ("%s\\%s (%s) is changing password of %s\n",
342 session_info->server_info->domain_name,
343 session_info->server_info->account_name,
344 dom_sid_string(mem_ctx, session_info->security_token->user_sid),
345 set_password_on_princ));
346 ret = ldb_transaction_start(samdb);
347 if (ret != LDB_SUCCESS) {
348 status = NT_STATUS_TRANSACTION_ABORTED;
349 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
350 status,
351 SAM_PWD_CHANGE_NO_ERROR,
352 NULL,
353 reply);
354 }
355
356 if (service_principal_name) {
357 status = crack_service_principal_name(samdb, mem_ctx,
358 set_password_on_princ,
359 &set_password_on_dn, NULL);
360 } else {
361 status = crack_user_principal_name(samdb, mem_ctx,
362 set_password_on_princ,
363 &set_password_on_dn, NULL);
364 }
365 free(set_password_on_princ);
366 if (!NT_STATUS_IS_OK(status)) {
367 ldb_transaction_cancel(samdb);
368 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
369 status,
370 SAM_PWD_CHANGE_NO_ERROR,
371 NULL,
372 reply);
373 }
374
375 if (NT_STATUS_IS_OK(status)) {
376 /* Admin password set */
377 status = samdb_set_password(samdb, mem_ctx,
378 set_password_on_dn, NULL,
379 &password, NULL, NULL,
380 false, /* this is not a user password change */
381 &reject_reason, &dominfo);
382 }
383
384 if (NT_STATUS_IS_OK(status)) {
385 ret = ldb_transaction_commit(samdb);
386 if (ret != LDB_SUCCESS) {
387 DEBUG(1,("Failed to commit transaction to set password on %s: %s\n",
388 ldb_dn_get_linearized(set_password_on_dn),
389 ldb_errstring(samdb)));
390 status = NT_STATUS_TRANSACTION_ABORTED;
391 }
392 } else {
393 ldb_transaction_cancel(samdb);
394 }
395 return kpasswd_make_pwchange_reply(kdc, mem_ctx,
396 status,
397 reject_reason,
398 dominfo,
399 reply);
400 }
401 default:
402 return kpasswdd_make_error_reply(kdc, mem_ctx,
403 KRB5_KPASSWD_BAD_VERSION,
404 talloc_asprintf(mem_ctx,
405 "Protocol version %u not supported",
406 version),
407 reply);
408 }
409 }
410
411 bool kpasswdd_process(struct kdc_server *kdc,
412 TALLOC_CTX *mem_ctx,
413 DATA_BLOB *input,
414 DATA_BLOB *reply,
415 struct tsocket_address *peer_addr,
416 struct tsocket_address *my_addr,
417 int datagram_reply)
418 {
419 bool ret;
420 const uint16_t header_len = 6;
421 uint16_t len;
422 uint16_t ap_req_len;
423 uint16_t krb_priv_len;
424 uint16_t version;
425 NTSTATUS nt_status;
426 DATA_BLOB ap_req, krb_priv_req;
427 DATA_BLOB krb_priv_rep = data_blob(NULL, 0);
428 DATA_BLOB ap_rep = data_blob(NULL, 0);
429 DATA_BLOB kpasswd_req, kpasswd_rep;
430 struct cli_credentials *server_credentials;
431 struct gensec_security *gensec_security;
432 TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
433
434 char *keytab_name;
435
436 if (!tmp_ctx) {
437 return false;
438 }
439
440 /* Be parinoid. We need to ensure we don't just let the
441 * caller lead us into a buffer overflow */
442 if (input->length <= header_len) {
443 talloc_free(tmp_ctx);
444 return false;
445 }
446
447 len = RSVAL(input->data, 0);
448 if (input->length != len) {
449 talloc_free(tmp_ctx);
450 return false;
451 }
452
453 /* There are two different versions of this protocol so far,
454 * plus others in the standards pipe. Fortunetly they all
455 * take a very similar framing */
456 version = RSVAL(input->data, 2);
457 ap_req_len = RSVAL(input->data, 4);
458 if ((ap_req_len >= len) || (ap_req_len + header_len) >= len) {
459 talloc_free(tmp_ctx);
460 return false;
461 }
462
463 krb_priv_len = len - ap_req_len;
464 ap_req = data_blob_const(&input->data[header_len], ap_req_len);
465 krb_priv_req = data_blob_const(&input->data[header_len + ap_req_len], krb_priv_len);
466
467 server_credentials = cli_credentials_init(tmp_ctx);
468 if (!server_credentials) {
469 DEBUG(1, ("Failed to init server credentials\n"));
470 return false;
471 }
472
473 /* We want the credentials subsystem to use the krb5 context
474 * we already have, rather than a new context */
475 cli_credentials_set_krb5_context(server_credentials, kdc->smb_krb5_context);
476 cli_credentials_set_conf(server_credentials, kdc->task->lp_ctx);
477
478 keytab_name = talloc_asprintf(server_credentials, "HDB:samba4&%p", kdc->base_ctx);
479
480 cli_credentials_set_username(server_credentials, "kadmin/changepw", CRED_SPECIFIED);
481 ret = cli_credentials_set_keytab_name(server_credentials, kdc->task->event_ctx, kdc->task->lp_ctx, keytab_name, CRED_SPECIFIED);
482 if (ret != 0) {
483 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
484 KRB5_KPASSWD_HARDERROR,
485 talloc_asprintf(mem_ctx,
486 "Failed to obtain server credentials for kadmin/changepw: %s\n",
487 nt_errstr(nt_status)),
488 &krb_priv_rep);
489 ap_rep.length = 0;
490 if (ret) {
491 goto reply;
492 }
493 talloc_free(tmp_ctx);
494 return ret;
495 }
496
497 /* We don't strictly need to call this wrapper, and could call
498 * gensec_server_start directly, as we have no need for NTLM
499 * and we have a PAC, but this ensures that the wrapper can be
500 * safely extended for other helpful things in future */
501 nt_status = samba_server_gensec_start(tmp_ctx, kdc->task->event_ctx,
502 kdc->task->msg_ctx,
503 kdc->task->lp_ctx,
504 server_credentials,
505 "kpasswd",
506 &gensec_security);
507 if (!NT_STATUS_IS_OK(nt_status)) {
508 talloc_free(tmp_ctx);
509 return false;
510 }
511
512 /* The kerberos PRIV packets include these addresses. MIT
513 * clients check that they are present */
514 #if 0
515 /* Skip this part for now, it breaks with a NetAPP filer and
516 * in any case where the client address is behind NAT. If
517 * older MIT clients need this, we might have to insert more
518 * complex code */
519
520 nt_status = gensec_set_local_address(gensec_security, peer_addr);
521 if (!NT_STATUS_IS_OK(nt_status)) {
522 talloc_free(tmp_ctx);
523 return false;
524 }
525 #endif
526
527 nt_status = gensec_set_local_address(gensec_security, my_addr);
528 if (!NT_STATUS_IS_OK(nt_status)) {
529 talloc_free(tmp_ctx);
530 return false;
531 }
532
533 /* We want the GENSEC wrap calls to generate PRIV tokens */
534 gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
535
536 nt_status = gensec_start_mech_by_name(gensec_security, "krb5");
537 if (!NT_STATUS_IS_OK(nt_status)) {
538 talloc_free(tmp_ctx);
539 return false;
540 }
541
542 /* Accept the AP-REQ and generate teh AP-REP we need for the reply */
543 nt_status = gensec_update(gensec_security, tmp_ctx, ap_req, &ap_rep);
544 if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
545
546 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
547 KRB5_KPASSWD_HARDERROR,
548 talloc_asprintf(mem_ctx,
549 "gensec_update failed: %s",
550 nt_errstr(nt_status)),
551 &krb_priv_rep);
552 ap_rep.length = 0;
553 if (ret) {
554 goto reply;
555 }
556 talloc_free(tmp_ctx);
557 return ret;
558 }
559
560 /* Extract the data from the KRB-PRIV half of the message */
561 nt_status = gensec_unwrap(gensec_security, tmp_ctx, &krb_priv_req, &kpasswd_req);
562 if (!NT_STATUS_IS_OK(nt_status)) {
563 ret = kpasswdd_make_unauth_error_reply(kdc, mem_ctx,
564 KRB5_KPASSWD_HARDERROR,
565 talloc_asprintf(mem_ctx,
566 "gensec_unwrap failed: %s",
567 nt_errstr(nt_status)),
568 &krb_priv_rep);
569 ap_rep.length = 0;
570 if (ret) {
571 goto reply;
572 }
573 talloc_free(tmp_ctx);
574 return ret;
575 }
576
577 /* Figure out something to do with it (probably changing a password...) */
578 ret = kpasswd_process_request(kdc, tmp_ctx,
579 gensec_security,
580 version,
581 &kpasswd_req, &kpasswd_rep);
582 if (!ret) {
583 /* Argh! */
584 return false;
585 }
586
587 /* And wrap up the reply: This ensures that the error message
588 * or success can be verified by the client */
589 nt_status = gensec_wrap(gensec_security, tmp_ctx,
590 &kpasswd_rep, &krb_priv_rep);
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_wrap failed: %s",
596 nt_errstr(nt_status)),
597 &krb_priv_rep);
598 ap_rep.length = 0;
599 if (ret) {
600 goto reply;
601 }
602 talloc_free(tmp_ctx);
603 return ret;
604 }
605
606 reply:
607 *reply = data_blob_talloc(mem_ctx, NULL, krb_priv_rep.length + ap_rep.length + header_len);
608 if (!reply->data) {
609 return false;
610 }
611
612 RSSVAL(reply->data, 0, reply->length);
613 RSSVAL(reply->data, 2, 1); /* This is a version 1 reply, MS change/set or otherwise */
614 RSSVAL(reply->data, 4, ap_rep.length);
615 memcpy(reply->data + header_len,
616 ap_rep.data,
617 ap_rep.length);
618 memcpy(reply->data + header_len + ap_rep.length,
619 krb_priv_rep.data,
620 krb_priv_rep.length);
621
622 talloc_free(tmp_ctx);
623 return ret;
624 }
625
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