libcli/cldap/cldap.c: don't hand huge values to tevent_timeval_add usecs
[samba.git] / libcli / security / create_descriptor.c
1 /*
2    Copyright (C) Nadezhda Ivanova 2009
3
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 3 of the License, or
7    (at your option) any later version.
8
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13
14    You should have received a copy of the GNU General Public License
15    along with this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 /*
19  *  Name: create_descriptor
20  *
21  *  Component: routines for calculating and creating security descriptors
22  *  as described in MS-DTYP 2.5.3.x
23  *
24  *  Description:
25  *
26  *
27  *  Author: Nadezhda Ivanova
28  */
29 #include "includes.h"
30 #include "libcli/security/security.h"
31 #include "librpc/gen_ndr/ndr_security.h"
32
33 /* Todos:
34  * build the security token dacl as follows:
35  * SYSTEM: GA, OWNER: GA, LOGIN_SID:GW|GE
36  * Need session id information for the login SID. Probably
37  * the best place for this is during token creation
38  *
39  * Implement SD Invariants
40  * ACE sorting rules
41  * LDAP_SERVER_SD_FLAGS_OID control
42  * ADTS 7.1.3.3 needs to be clarified
43  */
44
45 /* the mapping function for generic rights for DS.(GA,GR,GW,GX)
46  * The mapping function is passed as an argument to the
47  * descriptor calculating routine and depends on the security
48  * manager that calls the calculating routine.
49  * TODO: need similar mappings for the file system and
50  * registry security managers in order to make this code
51  * generic for all security managers
52  */
53
54 uint32_t map_generic_rights_ds(uint32_t access_mask)
55 {
56         if (access_mask & SEC_GENERIC_ALL) {
57                 access_mask |= SEC_ADS_GENERIC_ALL;
58                 access_mask &= ~SEC_GENERIC_ALL;
59         }
60
61         if (access_mask & SEC_GENERIC_EXECUTE) {
62                 access_mask |= SEC_ADS_GENERIC_EXECUTE;
63                 access_mask &= ~SEC_GENERIC_EXECUTE;
64         }
65
66         if (access_mask & SEC_GENERIC_WRITE) {
67                 access_mask |= SEC_ADS_GENERIC_WRITE;
68                 access_mask &= ~SEC_GENERIC_WRITE;
69         }
70
71         if (access_mask & SEC_GENERIC_READ) {
72                 access_mask |= SEC_ADS_GENERIC_READ;
73                 access_mask &= ~SEC_GENERIC_READ;
74         }
75
76         return access_mask;
77 }
78
79 /* Not sure what this has to be,
80 * and it does not seem to have any influence */
81 static bool object_in_list(struct GUID *object_list, struct GUID *object)
82 {
83         return true;
84 }
85  
86 /* returns true if the ACE gontains generic information
87  * that needs to be processed additionally */
88  
89 static bool desc_ace_has_generic(TALLOC_CTX *mem_ctx,
90                              struct security_ace *ace)
91 {
92         struct dom_sid *co, *cg;
93         co = dom_sid_parse_talloc(mem_ctx,  SID_CREATOR_OWNER);
94         cg = dom_sid_parse_talloc(mem_ctx,  SID_CREATOR_GROUP);
95         if (ace->access_mask & SEC_GENERIC_ALL || ace->access_mask & SEC_GENERIC_READ ||
96             ace->access_mask & SEC_GENERIC_WRITE || ace->access_mask & SEC_GENERIC_EXECUTE) {
97                 return true;
98         }
99         if (dom_sid_equal(&ace->trustee, co) || dom_sid_equal(&ace->trustee, cg)) {
100                 return true;
101         }
102         return false;
103 }
104
105 /* creates an ace in which the generic information is expanded */
106
107 static void desc_expand_generic(TALLOC_CTX *mem_ctx,
108                                 struct security_ace *new_ace,
109                                 struct dom_sid *owner,
110                                 struct dom_sid *group)
111 {
112         struct dom_sid *co, *cg;
113         co = dom_sid_parse_talloc(mem_ctx,  SID_CREATOR_OWNER);
114         cg = dom_sid_parse_talloc(mem_ctx,  SID_CREATOR_GROUP);
115         new_ace->access_mask = map_generic_rights_ds(new_ace->access_mask);
116         if (dom_sid_equal(&new_ace->trustee, co)) {
117                 new_ace->trustee = *owner;
118         }
119         if (dom_sid_equal(&new_ace->trustee, cg)) {
120                 new_ace->trustee = *group;
121         }
122         new_ace->flags = 0x0;
123 }
124
125 static struct security_acl *calculate_inherited_from_parent(TALLOC_CTX *mem_ctx,
126                                                             struct security_acl *acl,
127                                                             bool is_container,
128                                                             struct dom_sid *owner,
129                                                             struct dom_sid *group,
130                                                             struct GUID *object_list)
131 {
132         uint32_t i;
133         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
134         struct security_acl *tmp_acl = talloc_zero(mem_ctx, struct security_acl);
135         struct dom_sid *co, *cg;
136         if (!tmp_acl) {
137                 return NULL;
138         }
139
140         if (!acl) {
141                 return NULL;
142         }
143         co = dom_sid_parse_talloc(tmp_ctx,  SID_CREATOR_OWNER);
144         cg = dom_sid_parse_talloc(tmp_ctx,  SID_CREATOR_GROUP);
145
146         for (i=0; i < acl->num_aces; i++) {
147                 struct security_ace *ace = &acl->aces[i];
148                 if ((ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT) ||
149                     (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT)) {
150                         tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces,
151                                                        struct security_ace,
152                                                        tmp_acl->num_aces+1);
153                         if (tmp_acl->aces == NULL) {
154                                 talloc_free(tmp_ctx);
155                                 return NULL;
156                         }
157
158                         tmp_acl->aces[tmp_acl->num_aces] = *ace;
159                         tmp_acl->aces[tmp_acl->num_aces].flags |= SEC_ACE_FLAG_INHERITED_ACE;
160                         /* remove IO flag from the child's ace */
161                         if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY &&
162                             !desc_ace_has_generic(tmp_ctx, ace)) {
163                                 tmp_acl->aces[tmp_acl->num_aces].flags &= ~SEC_ACE_FLAG_INHERIT_ONLY;
164                         }
165
166                         if (is_container && (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT))
167                             tmp_acl->aces[tmp_acl->num_aces].flags |= SEC_ACE_FLAG_INHERIT_ONLY;
168
169                         if (ace->type == SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT ||
170                             ace->type == SEC_ACE_TYPE_ACCESS_DENIED_OBJECT) {
171                                 if (!object_in_list(object_list, &ace->object.object.type.type)) {
172                                         tmp_acl->aces[tmp_acl->num_aces].flags |= SEC_ACE_FLAG_INHERIT_ONLY;
173                                 }
174
175                         }
176                         tmp_acl->num_aces++;
177                         if (is_container) {
178                                 if (!(ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT) &&
179                                     (desc_ace_has_generic(tmp_ctx, ace))) {
180                                             tmp_acl->aces = talloc_realloc(tmp_acl,
181                                                                            tmp_acl->aces,
182                                                                            struct security_ace,
183                                                                            tmp_acl->num_aces+1);
184                                             if (tmp_acl->aces == NULL) {
185                                                     talloc_free(tmp_ctx);
186                                                     return NULL;
187                                             }
188                                             tmp_acl->aces[tmp_acl->num_aces] = *ace;
189                                             desc_expand_generic(tmp_ctx,
190                                                                 &tmp_acl->aces[tmp_acl->num_aces],
191                                                                 owner,
192                                                                 group);
193                                             tmp_acl->aces[tmp_acl->num_aces].flags = SEC_ACE_FLAG_INHERITED_ACE;
194                                             tmp_acl->num_aces++;
195                                 }
196                         }
197                 }
198         }
199         if (tmp_acl->num_aces == 0) {
200                 return NULL;
201         }
202         if (acl) {
203                 tmp_acl->revision = acl->revision;
204         }
205         return tmp_acl;
206 }
207
208 static struct security_acl *process_user_acl(TALLOC_CTX *mem_ctx,
209                                              struct security_acl *acl,
210                                              bool is_container,
211                                              struct dom_sid *owner,
212                                              struct dom_sid *group,
213                                              struct GUID *object_list,
214                                              bool is_protected)
215 {
216         uint32_t i;
217         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
218         struct security_acl *tmp_acl = talloc_zero(tmp_ctx, struct security_acl);
219         struct security_acl *new_acl;
220         struct dom_sid *co, *cg;
221
222         if (!acl)
223                 return NULL;
224
225         if (!tmp_acl)
226                 return NULL;
227
228         tmp_acl->revision = acl->revision;
229         DEBUG(6,(__location__ ": acl revision %d\n", acl->revision));
230
231         co = dom_sid_parse_talloc(tmp_ctx,  SID_CREATOR_OWNER);
232         cg = dom_sid_parse_talloc(tmp_ctx,  SID_CREATOR_GROUP);
233
234         for (i=0; i < acl->num_aces; i++){
235                 struct security_ace *ace = &acl->aces[i];
236                 /* Remove ID flags from user-provided ACEs
237                  * if we break inheritance, ignore them otherwise */
238                 if (ace->flags & SEC_ACE_FLAG_INHERITED_ACE) {
239                         if (is_protected) {
240                                 ace->flags &= ~SEC_ACE_FLAG_INHERITED_ACE;
241                         } else {
242                                 continue;
243                         }
244                 }
245
246                 if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY &&
247                     !(ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT ||
248                       ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT))
249                         continue;
250
251                 tmp_acl->aces = talloc_realloc(tmp_acl,
252                                                tmp_acl->aces,
253                                                struct security_ace,
254                                                tmp_acl->num_aces+1);
255                 tmp_acl->aces[tmp_acl->num_aces] = *ace;
256                 tmp_acl->num_aces++;
257                 if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
258                         continue;
259                 }
260                 /* if the ACE contains CO, CG, GA, GE, GR or GW, and is inheritable
261                  * it has to be expanded to two aces, the original as IO,
262                  * and another one where these are translated */
263                 if (desc_ace_has_generic(tmp_ctx, ace)) {
264                         if (!(ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) {
265                                 desc_expand_generic(tmp_ctx,
266                                                     &tmp_acl->aces[tmp_acl->num_aces-1],
267                                                     owner,
268                                                     group);
269                         } else {
270                                 /*The original ACE becomes read only */
271                                 tmp_acl->aces[tmp_acl->num_aces-1].flags |= SEC_ACE_FLAG_INHERIT_ONLY;
272                                 tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces,
273                                                                struct security_ace,
274                                                                tmp_acl->num_aces+1);
275                                 /* add a new ACE with expanded generic info */
276                                 tmp_acl->aces[tmp_acl->num_aces] = *ace;
277                                 desc_expand_generic(tmp_ctx,
278                                                     &tmp_acl->aces[tmp_acl->num_aces],
279                                                     owner,
280                                                     group);
281                                 tmp_acl->num_aces++;
282                         }
283                 }
284         }
285         new_acl = security_acl_dup(mem_ctx,tmp_acl);
286
287         if (new_acl)
288                 new_acl->revision = acl->revision;
289
290         talloc_free(tmp_ctx);
291         return new_acl;
292 }
293
294 static void cr_descr_log_descriptor(struct security_descriptor *sd,
295                                     const char *message,
296                                     int level)
297 {
298         if (sd) {
299                 DEBUG(level,("%s: %s\n", message,
300                              ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_descriptor,
301                                                      "", sd)));
302         }
303         else {
304                 DEBUG(level,("%s: NULL\n", message));
305         }
306 }
307
308 #if 0
309 static void cr_descr_log_acl(struct security_acl *acl,
310                                     const char *message,
311                                     int level)
312 {
313         if (acl) {
314                 DEBUG(level,("%s: %s\n", message,
315                              ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_acl,
316                                                      "", acl)));
317         }
318         else {
319                 DEBUG(level,("%s: NULL\n", message));
320         }
321 }
322 #endif
323
324 static bool compute_acl(struct security_descriptor *parent_sd,
325                         struct security_descriptor *creator_sd,
326                         bool is_container,
327                         uint32_t inherit_flags,
328                         struct GUID *object_list,
329                         uint32_t (*generic_map)(uint32_t access_mask),
330                         struct security_token *token,
331                         struct security_descriptor *new_sd) /* INOUT argument */
332 {
333         struct security_acl *user_dacl, *user_sacl, *inherited_dacl, *inherited_sacl;
334         int level = 10;
335
336         if (!parent_sd || !(inherit_flags & SEC_DACL_AUTO_INHERIT)) {
337                 inherited_dacl = NULL;
338         } else if (creator_sd && (creator_sd->type & SEC_DESC_DACL_PROTECTED)) {
339                 inherited_dacl = NULL;
340         } else {
341                 inherited_dacl = calculate_inherited_from_parent(new_sd,
342                                                                  parent_sd->dacl,
343                                                                  is_container,
344                                                                  new_sd->owner_sid,
345                                                                  new_sd->group_sid,
346                                                                  object_list);
347         }
348
349
350         if (!parent_sd || !(inherit_flags & SEC_SACL_AUTO_INHERIT)) {
351                 inherited_sacl = NULL;
352         } else if (creator_sd && (creator_sd->type & SEC_DESC_SACL_PROTECTED)) {
353                 inherited_sacl = NULL;
354         } else {
355                 inherited_sacl = calculate_inherited_from_parent(new_sd,
356                                                                  parent_sd->sacl,
357                                                                  is_container,
358                                                                  new_sd->owner_sid,
359                                                                  new_sd->group_sid,
360                                                                  object_list);
361         }
362
363         if (!creator_sd || (inherit_flags & SEC_DEFAULT_DESCRIPTOR)) {
364                 user_dacl = NULL;
365                 user_sacl = NULL;
366         } else {
367                 user_dacl = process_user_acl(new_sd,
368                                              creator_sd->dacl,
369                                              is_container,
370                                              new_sd->owner_sid,
371                                              new_sd->group_sid,
372                                              object_list,
373                                              creator_sd->type & SEC_DESC_DACL_PROTECTED);
374                 user_sacl = process_user_acl(new_sd,
375                                              creator_sd->sacl,
376                                              is_container,
377                                              new_sd->owner_sid,
378                                              new_sd->group_sid,
379                                              object_list,
380                                              creator_sd->type & SEC_DESC_SACL_PROTECTED);
381         }
382         cr_descr_log_descriptor(parent_sd, __location__"parent_sd", level);
383         cr_descr_log_descriptor(creator_sd,__location__ "creator_sd", level);
384
385         new_sd->dacl = security_acl_concatenate(new_sd, user_dacl, inherited_dacl);
386         if (new_sd->dacl) {
387                 new_sd->type |= SEC_DESC_DACL_PRESENT;
388         }
389         if (inherited_dacl) {
390                 new_sd->type |= SEC_DESC_DACL_AUTO_INHERITED;
391         }
392
393         new_sd->sacl = security_acl_concatenate(new_sd, user_sacl, inherited_sacl);
394         if (new_sd->sacl) {
395                 new_sd->type |= SEC_DESC_SACL_PRESENT;
396         }
397         if (inherited_sacl) {
398                 new_sd->type |= SEC_DESC_SACL_AUTO_INHERITED;
399         }
400         /* This is a hack to handle the fact that
401          * apprantly any AI flag provided by the user is preserved */
402         if (creator_sd)
403                 new_sd->type |= creator_sd->type;
404         cr_descr_log_descriptor(new_sd, __location__"final sd", level);
405         return true;
406 }
407
408 struct security_descriptor *create_security_descriptor(TALLOC_CTX *mem_ctx,
409                                                        struct security_descriptor *parent_sd,
410                                                        struct security_descriptor *creator_sd,
411                                                        bool is_container,
412                                                        struct GUID *object_list,
413                                                        uint32_t inherit_flags,
414                                                        struct security_token *token,
415                                                        struct dom_sid *default_owner, /* valid only for DS, NULL for the other RSs */
416                                                        struct dom_sid *default_group, /* valid only for DS, NULL for the other RSs */
417                                                        uint32_t (*generic_map)(uint32_t access_mask))
418 {
419         struct security_descriptor *new_sd;
420         struct dom_sid *new_owner = NULL;
421         struct dom_sid *new_group = NULL;
422
423         new_sd = security_descriptor_initialise(mem_ctx);
424         if (!new_sd) {
425                 return NULL;
426         }
427
428         if (!creator_sd || !creator_sd->owner_sid) {
429                 if ((inherit_flags & SEC_OWNER_FROM_PARENT) && parent_sd) {
430                         new_owner = parent_sd->owner_sid;
431                 } else if (!default_owner) {
432                         new_owner = &token->sids[PRIMARY_USER_SID_INDEX];
433                 } else {
434                         new_owner = default_owner;
435                         new_sd->type |= SEC_DESC_OWNER_DEFAULTED;
436                 }
437         } else {
438                 new_owner = creator_sd->owner_sid;
439         }
440
441         if (!creator_sd || !creator_sd->group_sid){
442                 if ((inherit_flags & SEC_GROUP_FROM_PARENT) && parent_sd) {
443                         new_group = parent_sd->group_sid;
444                 } else if (!default_group && token->num_sids > PRIMARY_GROUP_SID_INDEX) {
445                         new_group = &token->sids[PRIMARY_GROUP_SID_INDEX];
446                 } else if (!default_group) {
447                         /* This will happen only for anonymous, which has no other groups */
448                         new_group = &token->sids[PRIMARY_USER_SID_INDEX];
449                 } else {
450                         new_group = default_group;
451                         new_sd->type |= SEC_DESC_GROUP_DEFAULTED;
452                 }
453         } else {
454                 new_group = creator_sd->group_sid;
455         }
456
457         new_sd->owner_sid = talloc_memdup(new_sd, new_owner, sizeof(struct dom_sid));
458         new_sd->group_sid = talloc_memdup(new_sd, new_group, sizeof(struct dom_sid));
459         if (!new_sd->owner_sid || !new_sd->group_sid){
460                 talloc_free(new_sd);
461                 return NULL;
462         }
463
464         if (!compute_acl(parent_sd, creator_sd,
465                          is_container, inherit_flags, object_list,
466                          generic_map,token,new_sd)){
467                 talloc_free(new_sd);
468                 return NULL;
469         }
470
471         return new_sd;
472 }