passdb: Use dom_sid_str_buf
[amitay/samba.git] / source4 / kdc / wdc-samba4.c
1 /*
2    Unix SMB/CIFS implementation.
3
4    PAC Glue between Samba and the KDC
5
6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2009
7    Copyright (C) Simo Sorce <idra@samba.org> 2010
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
20    You should have received a copy of the GNU General Public License
21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
22 */
23
24 #include "includes.h"
25 #include "kdc/kdc-glue.h"
26 #include "kdc/pac-glue.h"
27
28 /*
29  * Given the right private pointer from hdb_samba4,
30  * get a PAC from the attached ldb messages.
31  *
32  * For PKINIT we also get pk_reply_key and can add PAC_CREDENTIAL_INFO.
33  */
34 static krb5_error_code samba_wdc_get_pac(void *priv, krb5_context context,
35                                          struct hdb_entry_ex *client,
36                                          const krb5_keyblock *pk_reply_key,
37                                          krb5_pac *pac)
38 {
39         TALLOC_CTX *mem_ctx;
40         DATA_BLOB *logon_blob = NULL;
41         DATA_BLOB *cred_ndr = NULL;
42         DATA_BLOB **cred_ndr_ptr = NULL;
43         DATA_BLOB _cred_blob = data_blob_null;
44         DATA_BLOB *cred_blob = NULL;
45         DATA_BLOB *upn_blob = NULL;
46         krb5_error_code ret;
47         NTSTATUS nt_status;
48         struct samba_kdc_entry *skdc_entry =
49                 talloc_get_type_abort(client->ctx,
50                 struct samba_kdc_entry);
51
52         mem_ctx = talloc_named(client->ctx, 0, "samba_get_pac context");
53         if (!mem_ctx) {
54                 return ENOMEM;
55         }
56
57         if (pk_reply_key != NULL) {
58                 cred_ndr_ptr = &cred_ndr;
59         }
60
61         nt_status = samba_kdc_get_pac_blobs(mem_ctx, skdc_entry,
62                                             &logon_blob,
63                                             cred_ndr_ptr,
64                                             &upn_blob);
65         if (!NT_STATUS_IS_OK(nt_status)) {
66                 talloc_free(mem_ctx);
67                 return EINVAL;
68         }
69
70         if (pk_reply_key != NULL && cred_ndr != NULL) {
71                 ret = samba_kdc_encrypt_pac_credentials(context,
72                                                         pk_reply_key,
73                                                         cred_ndr,
74                                                         mem_ctx,
75                                                         &_cred_blob);
76                 if (ret != 0) {
77                         talloc_free(mem_ctx);
78                         return ret;
79                 }
80                 cred_blob = &_cred_blob;
81         }
82
83         ret = samba_make_krb5_pac(context, logon_blob, cred_blob,
84                                   upn_blob, NULL, pac);
85
86         talloc_free(mem_ctx);
87         return ret;
88 }
89
90 static krb5_error_code samba_wdc_get_pac_compat(void *priv, krb5_context context,
91                                                 struct hdb_entry_ex *client,
92                                                 krb5_pac *pac)
93 {
94         return samba_wdc_get_pac(priv, context, client, NULL, pac);
95 }
96
97 /* Resign (and reform, including possibly new groups) a PAC */
98
99 static krb5_error_code samba_wdc_reget_pac(void *priv, krb5_context context,
100                                            const krb5_principal client_principal,
101                                            const krb5_principal delegated_proxy_principal,
102                                            struct hdb_entry_ex *client,
103                                            struct hdb_entry_ex *server,
104                                            struct hdb_entry_ex *krbtgt,
105                                            krb5_pac *pac)
106 {
107         struct samba_kdc_entry *p =
108                 talloc_get_type_abort(server->ctx,
109                 struct samba_kdc_entry);
110         struct samba_kdc_entry *krbtgt_skdc_entry =
111                 talloc_get_type_abort(krbtgt->ctx,
112                 struct samba_kdc_entry);
113         TALLOC_CTX *mem_ctx = talloc_named(p, 0, "samba_kdc_reget_pac context");
114         krb5_pac new_pac = NULL;
115         DATA_BLOB *pac_blob = NULL;
116         DATA_BLOB *upn_blob = NULL;
117         DATA_BLOB *deleg_blob = NULL;
118         krb5_error_code ret;
119         NTSTATUS nt_status;
120         struct PAC_SIGNATURE_DATA *pac_srv_sig;
121         struct PAC_SIGNATURE_DATA *pac_kdc_sig;
122         bool is_in_db, is_untrusted;
123         size_t num_types = 0;
124         uint32_t *types = NULL;
125         uint32_t forced_next_type = 0;
126         size_t i = 0;
127         ssize_t logon_info_idx = -1;
128         ssize_t delegation_idx = -1;
129         ssize_t logon_name_idx = -1;
130         ssize_t upn_dns_info_idx = -1;
131         ssize_t srv_checksum_idx = -1;
132         ssize_t kdc_checksum_idx = -1;
133
134         if (!mem_ctx) {
135                 return ENOMEM;
136         }
137
138         /* The user account may be set not to want the PAC */
139         if (!samba_princ_needs_pac(p)) {
140                 talloc_free(mem_ctx);
141                 return EINVAL;
142         }
143
144         /* If the krbtgt was generated by an RODC, and we are not that
145          * RODC, then we need to regenerate the PAC - we can't trust
146          * it */
147         ret = samba_krbtgt_is_in_db(krbtgt_skdc_entry, &is_in_db, &is_untrusted);
148         if (ret != 0) {
149                 talloc_free(mem_ctx);
150                 return ret;
151         }
152
153         if (is_untrusted) {
154                 struct samba_kdc_entry *client_skdc_entry = NULL;
155
156                 if (client == NULL) {
157                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
158                 }
159
160                 client_skdc_entry = talloc_get_type_abort(client->ctx,
161                                                           struct samba_kdc_entry);
162
163                 nt_status = samba_kdc_get_pac_blobs(mem_ctx, client_skdc_entry,
164                                                     &pac_blob, NULL, &upn_blob);
165                 if (!NT_STATUS_IS_OK(nt_status)) {
166                         talloc_free(mem_ctx);
167                         return EINVAL;
168                 }
169         } else {
170                 pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
171                 if (!pac_blob) {
172                         talloc_free(mem_ctx);
173                         return ENOMEM;
174                 }
175
176                 pac_srv_sig = talloc_zero(mem_ctx, struct PAC_SIGNATURE_DATA);
177                 if (!pac_srv_sig) {
178                         talloc_free(mem_ctx);
179                         return ENOMEM;
180                 }
181
182                 pac_kdc_sig = talloc_zero(mem_ctx, struct PAC_SIGNATURE_DATA);
183                 if (!pac_kdc_sig) {
184                         talloc_free(mem_ctx);
185                         return ENOMEM;
186                 }
187
188                 nt_status = samba_kdc_update_pac_blob(mem_ctx, context,
189                                                       krbtgt_skdc_entry, p,
190                                                       *pac, pac_blob,
191                                                       pac_srv_sig, pac_kdc_sig);
192                 if (!NT_STATUS_IS_OK(nt_status)) {
193                         DEBUG(0, ("Building PAC failed: %s\n",
194                                   nt_errstr(nt_status)));
195                         talloc_free(mem_ctx);
196                         return EINVAL;
197                 }
198                 
199                 if (is_in_db) {
200                         /* Now check the KDC signature, fetching the correct key based on the enc type */
201                         ret = kdc_check_pac(context, pac_srv_sig->signature, pac_kdc_sig, krbtgt);
202                         if (ret != 0) {
203                                 DEBUG(1, ("PAC KDC signature failed to verify\n"));
204                                 talloc_free(mem_ctx);
205                                 return ret;
206                         }
207                 }
208         }
209
210         if (delegated_proxy_principal) {
211                 deleg_blob = talloc_zero(mem_ctx, DATA_BLOB);
212                 if (!deleg_blob) {
213                         talloc_free(mem_ctx);
214                         return ENOMEM;
215                 }
216
217                 nt_status = samba_kdc_update_delegation_info_blob(mem_ctx,
218                                         context, *pac,
219                                         server->entry.principal,
220                                         delegated_proxy_principal,
221                                         deleg_blob);
222                 if (!NT_STATUS_IS_OK(nt_status)) {
223                         DEBUG(0, ("Building PAC failed: %s\n",
224                                   nt_errstr(nt_status)));
225                         talloc_free(mem_ctx);
226                         return EINVAL;
227                 }
228         }
229
230         /* Check the types of the given PAC */
231         ret = krb5_pac_get_types(context, *pac, &num_types, &types);
232         if (ret != 0) {
233                 talloc_free(mem_ctx);
234                 return ret;
235         }
236
237         for (i = 0; i < num_types; i++) {
238                 switch (types[i]) {
239                 case PAC_TYPE_LOGON_INFO:
240                         if (logon_info_idx != -1) {
241                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
242                                           (int)types[i],
243                                           (int)logon_info_idx,
244                                           (int)i));
245                                 SAFE_FREE(types);
246                                 talloc_free(mem_ctx);
247                                 return EINVAL;
248                         }
249                         logon_info_idx = i;
250                         break;
251                 case PAC_TYPE_CONSTRAINED_DELEGATION:
252                         if (delegation_idx != -1) {
253                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
254                                           (int)types[i],
255                                           (int)logon_info_idx,
256                                           (int)i));
257                                 SAFE_FREE(types);
258                                 talloc_free(mem_ctx);
259                                 return EINVAL;
260                         }
261                         delegation_idx = i;
262                         break;
263                 case PAC_TYPE_LOGON_NAME:
264                         if (logon_name_idx != -1) {
265                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
266                                           (int)types[i],
267                                           (int)logon_info_idx,
268                                           (int)i));
269                                 SAFE_FREE(types);
270                                 talloc_free(mem_ctx);
271                                 return EINVAL;
272                         }
273                         logon_name_idx = i;
274                         break;
275                 case PAC_TYPE_UPN_DNS_INFO:
276                         if (upn_dns_info_idx != -1) {
277                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
278                                           (int)types[i],
279                                           (int)logon_info_idx,
280                                           (int)i));
281                                 SAFE_FREE(types);
282                                 talloc_free(mem_ctx);
283                                 return EINVAL;
284                         }
285                         upn_dns_info_idx = i;
286                         break;
287                 case PAC_TYPE_SRV_CHECKSUM:
288                         if (srv_checksum_idx != -1) {
289                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
290                                           (int)types[i],
291                                           (int)logon_info_idx,
292                                           (int)i));
293                                 SAFE_FREE(types);
294                                 talloc_free(mem_ctx);
295                                 return EINVAL;
296                         }
297                         srv_checksum_idx = i;
298                         break;
299                 case PAC_TYPE_KDC_CHECKSUM:
300                         if (kdc_checksum_idx != -1) {
301                                 DEBUG(1, ("logon type[%d] twice [%d] and [%d]: \n",
302                                           (int)types[i],
303                                           (int)logon_info_idx,
304                                           (int)i));
305                                 SAFE_FREE(types);
306                                 talloc_free(mem_ctx);
307                                 return EINVAL;
308                         }
309                         kdc_checksum_idx = i;
310                         break;
311                 default:
312                         continue;
313                 }
314         }
315
316         if (logon_info_idx == -1) {
317                 DEBUG(1, ("PAC_TYPE_LOGON_INFO missing\n"));
318                 SAFE_FREE(types);
319                 talloc_free(mem_ctx);
320                 return EINVAL;
321         }
322         if (logon_name_idx == -1) {
323                 DEBUG(1, ("PAC_TYPE_LOGON_NAME missing\n"));
324                 SAFE_FREE(types);
325                 talloc_free(mem_ctx);
326                 return EINVAL;
327         }
328         if (srv_checksum_idx == -1) {
329                 DEBUG(1, ("PAC_TYPE_SRV_CHECKSUM missing\n"));
330                 SAFE_FREE(types);
331                 talloc_free(mem_ctx);
332                 return EINVAL;
333         }
334         if (kdc_checksum_idx == -1) {
335                 DEBUG(1, ("PAC_TYPE_KDC_CHECKSUM missing\n"));
336                 SAFE_FREE(types);
337                 talloc_free(mem_ctx);
338                 return EINVAL;
339         }
340
341         /* Build an updated PAC */
342         ret = krb5_pac_init(context, &new_pac);
343         if (ret != 0) {
344                 SAFE_FREE(types);
345                 talloc_free(mem_ctx);
346                 return ret;
347         }
348
349         for (i = 0;;) {
350                 const uint8_t zero_byte = 0;
351                 krb5_data type_data;
352                 DATA_BLOB type_blob = data_blob_null;
353                 uint32_t type;
354
355                 if (forced_next_type != 0) {
356                         /*
357                          * We need to inject possible missing types
358                          */
359                         type = forced_next_type;
360                         forced_next_type = 0;
361                 } else if (i < num_types) {
362                         type = types[i];
363                         i++;
364                 } else {
365                         break;
366                 }
367
368                 switch (type) {
369                 case PAC_TYPE_LOGON_INFO:
370                         type_blob = *pac_blob;
371
372                         if (delegation_idx == -1 && deleg_blob != NULL) {
373                                 /* inject CONSTRAINED_DELEGATION behind */
374                                 forced_next_type = PAC_TYPE_CONSTRAINED_DELEGATION;
375                         }
376                         break;
377                 case PAC_TYPE_CONSTRAINED_DELEGATION:
378                         if (deleg_blob != NULL) {
379                                 type_blob = *deleg_blob;
380                         }
381                         break;
382                 case PAC_TYPE_CREDENTIAL_INFO:
383                         /*
384                          * Note that we copy the credential blob,
385                          * as it's only usable with the PKINIT based
386                          * AS-REP reply key, it's only available on the
387                          * host which did the AS-REQ/AS-REP exchange.
388                          *
389                          * This matches Windows 2008R2...
390                          */
391                         break;
392                 case PAC_TYPE_LOGON_NAME:
393                         /*
394                          * this is generated in the main KDC code
395                          * we just add a place holder here.
396                          */
397                         type_blob = data_blob_const(&zero_byte, 1);
398
399                         if (upn_dns_info_idx == -1 && upn_blob != NULL) {
400                                 /* inject UPN_DNS_INFO behind */
401                                 forced_next_type = PAC_TYPE_UPN_DNS_INFO;
402                         }
403                         break;
404                 case PAC_TYPE_UPN_DNS_INFO:
405                         /*
406                          * Replace in the RODC case, otherwise
407                          * upn_blob is NULL and we just copy.
408                          */
409                         if (upn_blob != NULL) {
410                                 type_blob = *upn_blob;
411                         }
412                         break;
413                 case PAC_TYPE_SRV_CHECKSUM:
414                         /*
415                          * this are generated in the main KDC code
416                          * we just add a place holder here.
417                          */
418                         type_blob = data_blob_const(&zero_byte, 1);
419                         break;
420                 case PAC_TYPE_KDC_CHECKSUM:
421                         /*
422                          * this are generated in the main KDC code
423                          * we just add a place holders here.
424                          */
425                         type_blob = data_blob_const(&zero_byte, 1);
426                         break;
427                 default:
428                         /* just copy... */
429                         break;
430                 }
431
432                 if (type_blob.length != 0) {
433                         ret = smb_krb5_copy_data_contents(&type_data,
434                                                           type_blob.data,
435                                                           type_blob.length);
436                         if (ret != 0) {
437                                 SAFE_FREE(types);
438                                 krb5_pac_free(context, new_pac);
439                                 talloc_free(mem_ctx);
440                                 return ret;
441                         }
442                 } else {
443                         ret = krb5_pac_get_buffer(context, *pac,
444                                                   type, &type_data);
445                         if (ret != 0) {
446                                 SAFE_FREE(types);
447                                 krb5_pac_free(context, new_pac);
448                                 talloc_free(mem_ctx);
449                                 return ret;
450                         }
451                 }
452
453                 ret = krb5_pac_add_buffer(context, new_pac,
454                                           type, &type_data);
455                 smb_krb5_free_data_contents(context, &type_data);
456                 if (ret != 0) {
457                         SAFE_FREE(types);
458                         krb5_pac_free(context, new_pac);
459                         talloc_free(mem_ctx);
460                         return ret;
461                 }
462         }
463
464         SAFE_FREE(types);
465
466         /* We now replace the pac */
467         krb5_pac_free(context, *pac);
468         *pac = new_pac;
469
470         talloc_free(mem_ctx);
471         return ret;
472 }
473
474 static char *get_netbios_name(TALLOC_CTX *mem_ctx, HostAddresses *addrs)
475 {
476         char *nb_name = NULL;
477         size_t len;
478         unsigned int i;
479
480         for (i = 0; addrs && i < addrs->len; i++) {
481                 if (addrs->val[i].addr_type != KRB5_ADDRESS_NETBIOS) {
482                         continue;
483                 }
484                 len = MIN(addrs->val[i].address.length, 15);
485                 nb_name = talloc_strndup(mem_ctx,
486                                          addrs->val[i].address.data, len);
487                 if (nb_name) {
488                         break;
489                 }
490         }
491
492         if ((nb_name == NULL) || (nb_name[0] == '\0')) {
493                 return NULL;
494         }
495
496         /* Strip space padding */
497         for (len = strlen(nb_name) - 1;
498              (len > 0) && (nb_name[len] == ' ');
499              --len) {
500                 nb_name[len] = '\0';
501         }
502
503         return nb_name;
504 }
505
506 static krb5_data fill_krb5_data(void *data, size_t length)
507 {
508         krb5_data kdata;
509
510         kdata.data = data;
511         kdata.length = length;
512
513         return kdata;
514 }
515
516 /* this function allocates 'data' using malloc.
517  * The caller is responsible for freeing it */
518 static void samba_kdc_build_edata_reply(NTSTATUS nt_status, DATA_BLOB *e_data)
519 {
520         krb5_error_code ret = 0;
521         PA_DATA pa;
522         unsigned char *buf;
523         size_t len;
524
525         if (!e_data)
526                 return;
527
528         e_data->data   = NULL;
529         e_data->length = 0;
530
531         pa.padata_type          = KRB5_PADATA_PW_SALT;
532         pa.padata_value.length  = 12;
533         pa.padata_value.data    = malloc(pa.padata_value.length);
534         if (!pa.padata_value.data) {
535                 e_data->length = 0;
536                 e_data->data = NULL;
537                 return;
538         }
539
540         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
541         SIVAL(pa.padata_value.data, 4, 0);
542         SIVAL(pa.padata_value.data, 8, 1);
543
544         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
545         free(pa.padata_value.data);
546         if (ret) {
547                 return;
548         }
549
550         e_data->data   = buf;
551         e_data->length = len;
552
553         return;
554 }
555
556
557 static krb5_error_code samba_wdc_check_client_access(void *priv,
558                                                      krb5_context context,
559                                                      krb5_kdc_configuration *config,
560                                                      hdb_entry_ex *client_ex, const char *client_name,
561                                                      hdb_entry_ex *server_ex, const char *server_name,
562                                                      KDC_REQ *req,
563                                                      krb5_data *e_data)
564 {
565         struct samba_kdc_entry *kdc_entry;
566         bool password_change;
567         char *workstation;
568         NTSTATUS nt_status;
569
570         kdc_entry = talloc_get_type(client_ex->ctx, struct samba_kdc_entry);
571         password_change = (server_ex && server_ex->entry.flags.change_pw);
572         workstation = get_netbios_name((TALLOC_CTX *)client_ex->ctx,
573                                         req->req_body.addresses);
574
575         nt_status = samba_kdc_check_client_access(kdc_entry,
576                                                   client_name,
577                                                   workstation,
578                                                   password_change);
579
580         if (!NT_STATUS_IS_OK(nt_status)) {
581                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
582                         return ENOMEM;
583                 }
584
585                 if (e_data) {
586                         DATA_BLOB data;
587
588                         samba_kdc_build_edata_reply(nt_status, &data);
589                         *e_data = fill_krb5_data(data.data, data.length);
590                 }
591
592                 return samba_kdc_map_policy_err(nt_status);
593         }
594
595         /* Now do the standard Heimdal check */
596         return kdc_check_flags(context, config,
597                                client_ex, client_name,
598                                server_ex, server_name,
599                                req->msg_type == krb_as_req);
600 }
601
602 static krb5_error_code samba_wdc_plugin_init(krb5_context context, void **ptr)
603 {
604         *ptr = NULL;
605         return 0;
606 }
607
608 static void samba_wdc_plugin_fini(void *ptr)
609 {
610         return;
611 }
612
613 struct krb5plugin_windc_ftable windc_plugin_table = {
614         .minor_version = KRB5_WINDC_PLUGIN_MINOR,
615         .init = samba_wdc_plugin_init,
616         .fini = samba_wdc_plugin_fini,
617         .pac_generate = samba_wdc_get_pac_compat,
618         .pac_verify = samba_wdc_reget_pac,
619         .client_access = samba_wdc_check_client_access,
620         .pac_pk_generate = samba_wdc_get_pac,
621 };
622
623