source: vendor/3.5.8/source3/lib/util_seaccess.c

Last change on this file was 594, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update vendor to version 3.5.8
File size: 8.0 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3
4 Copyright (C) Andrew Tridgell 2004
5 Copyright (C) Gerald Carter 2005
6 Copyright (C) Volker Lendecke 2007
7 Copyright (C) Jeremy Allison 2008
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
25extern NT_USER_TOKEN anonymous_token;
26
27/* Map generic access rights to object specific rights. This technique is
28 used to give meaning to assigning read, write, execute and all access to
29 objects. Each type of object has its own mapping of generic to object
30 specific access rights. */
31
32void se_map_generic(uint32 *access_mask, const struct generic_mapping *mapping)
33{
34 uint32 old_mask = *access_mask;
35
36 if (*access_mask & GENERIC_READ_ACCESS) {
37 *access_mask &= ~GENERIC_READ_ACCESS;
38 *access_mask |= mapping->generic_read;
39 }
40
41 if (*access_mask & GENERIC_WRITE_ACCESS) {
42 *access_mask &= ~GENERIC_WRITE_ACCESS;
43 *access_mask |= mapping->generic_write;
44 }
45
46 if (*access_mask & GENERIC_EXECUTE_ACCESS) {
47 *access_mask &= ~GENERIC_EXECUTE_ACCESS;
48 *access_mask |= mapping->generic_execute;
49 }
50
51 if (*access_mask & GENERIC_ALL_ACCESS) {
52 *access_mask &= ~GENERIC_ALL_ACCESS;
53 *access_mask |= mapping->generic_all;
54 }
55
56 if (old_mask != *access_mask) {
57 DEBUG(10, ("se_map_generic(): mapped mask 0x%08x to 0x%08x\n",
58 old_mask, *access_mask));
59 }
60}
61
62/* Map generic access rights to object specific rights for all the ACE's
63 * in a security_acl.
64 */
65
66void security_acl_map_generic(struct security_acl *sa,
67 const struct generic_mapping *mapping)
68{
69 unsigned int i;
70
71 if (!sa) {
72 return;
73 }
74
75 for (i = 0; i < sa->num_aces; i++) {
76 se_map_generic(&sa->aces[i].access_mask, mapping);
77 }
78}
79
80/* Map standard access rights to object specific rights. This technique is
81 used to give meaning to assigning read, write, execute and all access to
82 objects. Each type of object has its own mapping of standard to object
83 specific access rights. */
84
85void se_map_standard(uint32 *access_mask, struct standard_mapping *mapping)
86{
87 uint32 old_mask = *access_mask;
88
89 if (*access_mask & SEC_STD_READ_CONTROL) {
90 *access_mask &= ~SEC_STD_READ_CONTROL;
91 *access_mask |= mapping->std_read;
92 }
93
94 if (*access_mask & (SEC_STD_DELETE|SEC_STD_WRITE_DAC|SEC_STD_WRITE_OWNER|SEC_STD_SYNCHRONIZE)) {
95 *access_mask &= ~(SEC_STD_DELETE|SEC_STD_WRITE_DAC|SEC_STD_WRITE_OWNER|SEC_STD_SYNCHRONIZE);
96 *access_mask |= mapping->std_all;
97 }
98
99 if (old_mask != *access_mask) {
100 DEBUG(10, ("se_map_standard(): mapped mask 0x%08x to 0x%08x\n",
101 old_mask, *access_mask));
102 }
103}
104
105/*
106 perform a SEC_FLAG_MAXIMUM_ALLOWED access check
107*/
108static uint32_t access_check_max_allowed(const struct security_descriptor *sd,
109 const NT_USER_TOKEN *token)
110{
111 uint32_t denied = 0, granted = 0;
112 unsigned i;
113
114 if (is_sid_in_token(token, sd->owner_sid)) {
115 granted |= SEC_STD_WRITE_DAC | SEC_STD_READ_CONTROL | SEC_STD_DELETE;
116 } else if (user_has_privileges(token, &se_restore)) {
117 granted |= SEC_STD_DELETE;
118 }
119
120 if (sd->dacl == NULL) {
121 return granted & ~denied;
122 }
123
124 for (i = 0;i<sd->dacl->num_aces; i++) {
125 struct security_ace *ace = &sd->dacl->aces[i];
126
127 if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
128 continue;
129 }
130
131 if (!is_sid_in_token(token, &ace->trustee)) {
132 continue;
133 }
134
135 switch (ace->type) {
136 case SEC_ACE_TYPE_ACCESS_ALLOWED:
137 granted |= ace->access_mask;
138 break;
139 case SEC_ACE_TYPE_ACCESS_DENIED:
140 case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
141 denied |= ace->access_mask;
142 break;
143 default: /* Other ACE types not handled/supported */
144 break;
145 }
146 }
147
148 return granted & ~denied;
149}
150
151/*
152 The main entry point for access checking. If returning ACCESS_DENIED
153 this function returns the denied bits in the uint32_t pointed
154 to by the access_granted pointer.
155*/
156NTSTATUS se_access_check(const struct security_descriptor *sd,
157 const NT_USER_TOKEN *token,
158 uint32_t access_desired,
159 uint32_t *access_granted)
160{
161 int i;
162 uint32_t bits_remaining;
163
164 *access_granted = access_desired;
165 bits_remaining = access_desired;
166
167 /* handle the maximum allowed flag */
168 if (access_desired & SEC_FLAG_MAXIMUM_ALLOWED) {
169 uint32_t orig_access_desired = access_desired;
170
171 access_desired |= access_check_max_allowed(sd, token);
172 access_desired &= ~SEC_FLAG_MAXIMUM_ALLOWED;
173 *access_granted = access_desired;
174 bits_remaining = access_desired & ~SEC_STD_DELETE;
175
176 DEBUG(10,("se_access_check: MAX desired = 0x%x, granted = 0x%x, remaining = 0x%x\n",
177 orig_access_desired,
178 *access_granted,
179 bits_remaining));
180 }
181
182 if (access_desired & SEC_FLAG_SYSTEM_SECURITY) {
183 if (user_has_privileges(token, &se_security)) {
184 bits_remaining &= ~SEC_FLAG_SYSTEM_SECURITY;
185 } else {
186 return NT_STATUS_PRIVILEGE_NOT_HELD;
187 }
188 }
189
190 /* a NULL dacl allows access */
191 if ((sd->type & SEC_DESC_DACL_PRESENT) && sd->dacl == NULL) {
192 *access_granted = access_desired;
193 return NT_STATUS_OK;
194 }
195
196 /* the owner always gets SEC_STD_WRITE_DAC, SEC_STD_READ_CONTROL and SEC_STD_DELETE */
197 if ((bits_remaining & (SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL|SEC_STD_DELETE)) &&
198 is_sid_in_token(token, sd->owner_sid)) {
199 bits_remaining &= ~(SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL|SEC_STD_DELETE);
200 }
201 if ((bits_remaining & SEC_STD_DELETE) &&
202 user_has_privileges(token, &se_restore)) {
203 bits_remaining &= ~SEC_STD_DELETE;
204 }
205
206 if (sd->dacl == NULL) {
207 goto done;
208 }
209
210 /* check each ace in turn. */
211 for (i=0; bits_remaining && i < sd->dacl->num_aces; i++) {
212 struct security_ace *ace = &sd->dacl->aces[i];
213
214 if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
215 continue;
216 }
217
218 if (!is_sid_in_token(token, &ace->trustee)) {
219 continue;
220 }
221
222 switch (ace->type) {
223 case SEC_ACE_TYPE_ACCESS_ALLOWED:
224 bits_remaining &= ~ace->access_mask;
225 break;
226 case SEC_ACE_TYPE_ACCESS_DENIED:
227 case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
228 if (bits_remaining & ace->access_mask) {
229 return NT_STATUS_ACCESS_DENIED;
230 }
231 break;
232 default: /* Other ACE types not handled/supported */
233 break;
234 }
235 }
236
237done:
238 if (bits_remaining != 0) {
239 *access_granted = bits_remaining;
240 return NT_STATUS_ACCESS_DENIED;
241 }
242
243 return NT_STATUS_OK;
244}
245
246/*******************************************************************
247 samr_make_sam_obj_sd
248 ********************************************************************/
249
250NTSTATUS samr_make_sam_obj_sd(TALLOC_CTX *ctx, SEC_DESC **psd, size_t *sd_size)
251{
252 DOM_SID adm_sid;
253 DOM_SID act_sid;
254
255 SEC_ACE ace[3];
256
257 SEC_ACL *psa = NULL;
258
259 sid_copy(&adm_sid, &global_sid_Builtin);
260 sid_append_rid(&adm_sid, BUILTIN_ALIAS_RID_ADMINS);
261
262 sid_copy(&act_sid, &global_sid_Builtin);
263 sid_append_rid(&act_sid, BUILTIN_ALIAS_RID_ACCOUNT_OPS);
264
265 /*basic access for every one*/
266 init_sec_ace(&ace[0], &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED,
267 GENERIC_RIGHTS_SAM_EXECUTE | GENERIC_RIGHTS_SAM_READ, 0);
268
269 /*full access for builtin aliases Administrators and Account Operators*/
270 init_sec_ace(&ace[1], &adm_sid,
271 SEC_ACE_TYPE_ACCESS_ALLOWED, GENERIC_RIGHTS_SAM_ALL_ACCESS, 0);
272 init_sec_ace(&ace[2], &act_sid,
273 SEC_ACE_TYPE_ACCESS_ALLOWED, GENERIC_RIGHTS_SAM_ALL_ACCESS, 0);
274
275 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 3, ace)) == NULL)
276 return NT_STATUS_NO_MEMORY;
277
278 if ((*psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
279 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
280 psa, sd_size)) == NULL)
281 return NT_STATUS_NO_MEMORY;
282
283 return NT_STATUS_OK;
284}
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