source4/dsdb/samdb/ldb_modules/acl_util.c

   1 /*
   2   ACL utility functions
   3
   4   Copyright (C) Nadezhda Ivanova 2010
   5
   6   This program is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation; either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   This program is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21  *  Name: acl_util
  22  *
  23  *  Component: ldb ACL modules
  24  *
  25  *  Description: Some auxiliary functions used for access checking
  26  *
  27  *  Author: Nadezhda Ivanova
  28  */
  29 #include "includes.h"
  30 #include "ldb_module.h"
  31 #include "auth/auth.h"
  32 #include "libcli/security/security.h"
  33 #include "dsdb/samdb/samdb.h"
  34 #include "librpc/gen_ndr/ndr_security.h"
  35 #include "param/param.h"
  36 #include "dsdb/samdb/ldb_modules/util.h"
  37
  38 struct security_token *acl_user_token(struct ldb_module *module)
  39 {
  40         struct ldb_context *ldb = ldb_module_get_ctx(module);
  41         struct auth_session_info *session_info
  42                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
  43         if(!session_info) {
  44                 return NULL;
  45         }
  46         return session_info->security_token;
  47 }
  48
  49 /* performs an access check from inside the module stack
  50  * given the dn of the object to be checked, the required access
  51  * guid is either the guid of the extended right, or NULL
  52  */
  53
  54 int dsdb_module_check_access_on_dn(struct ldb_module *module,
  55                                    TALLOC_CTX *mem_ctx,
  56                                    struct ldb_dn *dn,
  57                                    uint32_t access_mask,
  58                                    const struct GUID *guid,
  59                                    struct ldb_request *parent)
  60 {
  61         int ret;
  62         struct ldb_result *acl_res;
  63         static const char *acl_attrs[] = {
  64                 "nTSecurityDescriptor",
  65                 "objectSid",
  66                 NULL
  67         };
  68         struct ldb_context *ldb = ldb_module_get_ctx(module);
  69         struct auth_session_info *session_info
  70                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
  71         if(!session_info) {
  72                 return ldb_operr(ldb);
  73         }
  74         ret = dsdb_module_search_dn(module, mem_ctx, &acl_res, dn,
  75                                     acl_attrs,
  76                                     DSDB_FLAG_NEXT_MODULE |
  77                                     DSDB_FLAG_AS_SYSTEM |
  78                                     DSDB_SEARCH_SHOW_RECYCLED,
  79                                     parent);
  80         if (ret != LDB_SUCCESS) {
  81                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
  82                                        "access_check: failed to find object %s\n",
  83                                        ldb_dn_get_linearized(dn));
  84                 return ret;
  85         }
  86         return dsdb_check_access_on_dn_internal(ldb, acl_res,
  87                                                 mem_ctx,
  88                                                 session_info->security_token,
  89                                                 dn,
  90                                                 access_mask,
  91                                                 guid);
  92 }
  93
  94 int acl_check_access_on_attribute(struct ldb_module *module,
  95                                   TALLOC_CTX *mem_ctx,
  96                                   struct security_descriptor *sd,
  97                                   struct dom_sid *rp_sid,
  98                                   uint32_t access_mask,
  99                                   const struct dsdb_attribute *attr)
 100 {
 101         int ret;
 102         NTSTATUS status;
 103         uint32_t access_granted;
 104         struct object_tree *root = NULL;
 105         struct object_tree *new_node = NULL;
 106         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 107         struct security_token *token = acl_user_token(module);
 108
 109         if (!GUID_all_zero(&attr->attributeSecurityGUID)) {
 110                 if (!insert_in_object_tree(tmp_ctx,
 111                                            &attr->attributeSecurityGUID,
 112                                            access_mask, &root,
 113                                            &new_node)) {
 114                         DEBUG(10, ("acl_search: cannot add to object tree securityGUID\n"));
 115                         goto fail;
 116                 }
 117
 118                 if (!insert_in_object_tree(tmp_ctx,
 119                                            &attr->schemaIDGUID,
 120                                            access_mask, &new_node,
 121                                            &new_node)) {
 122                         DEBUG(10, ("acl_search: cannot add to object tree attributeGUID\n"));
 123                         goto fail;
 124                 }
 125         } else {
 126                 if (!insert_in_object_tree(tmp_ctx,
 127                                            &attr->schemaIDGUID,
 128                                            access_mask, &root,
 129                                            &new_node)) {
 130                         DEBUG(10, ("acl_search: cannot add to object tree attributeGUID\n"));
 131                         goto fail;
 132                 }
 133         }
 134
 135         status = sec_access_check_ds(sd, token,
 136                                      access_mask,
 137                                      &access_granted,
 138                                      root,
 139                                      rp_sid);
 140         if (!NT_STATUS_IS_OK(status)) {
 141                 ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 142         }
 143         else {
 144                 ret = LDB_SUCCESS;
 145         }
 146         talloc_free(tmp_ctx);
 147         return ret;
 148 fail:
 149         talloc_free(tmp_ctx);
 150         return ldb_operr(ldb_module_get_ctx(module));
 151 }
 152
 153
 154 /* checks for validated writes */
 155 int acl_check_extended_right(TALLOC_CTX *mem_ctx,
 156                              struct security_descriptor *sd,
 157                              struct security_token *token,
 158                              const char *ext_right,
 159                              uint32_t right_type,
 160                              struct dom_sid *sid)
 161 {
 162         struct GUID right;
 163         NTSTATUS status;
 164         uint32_t access_granted;
 165         struct object_tree *root = NULL;
 166         struct object_tree *new_node = NULL;
 167         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 168
 169         GUID_from_string(ext_right, &right);
 170
 171         if (!insert_in_object_tree(tmp_ctx, &right, right_type,
 172                                    &root, &new_node)) {
 173                 DEBUG(10, ("acl_ext_right: cannot add to object tree\n"));
 174                 talloc_free(tmp_ctx);
 175                 return LDB_ERR_OPERATIONS_ERROR;
 176         }
 177         status = sec_access_check_ds(sd, token,
 178                                      right_type,
 179                                      &access_granted,
 180                                      root,
 181                                      sid);
 182
 183         if (!NT_STATUS_IS_OK(status)) {
 184                 talloc_free(tmp_ctx);
 185                 return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 186         }
 187         talloc_free(tmp_ctx);
 188         return LDB_SUCCESS;
 189 }
 190
 191 const char *acl_user_name(TALLOC_CTX *mem_ctx, struct ldb_module *module)
 192 {
 193         struct ldb_context *ldb = ldb_module_get_ctx(module);
 194         struct auth_session_info *session_info
 195                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
 196         if (!session_info) {
 197                 return "UNKNOWN (NULL)";
 198         }
 199
 200         return talloc_asprintf(mem_ctx, "%s\\%s",
 201                                session_info->info->domain_name,
 202                                session_info->info->account_name);
 203 }
 204
 205 uint32_t dsdb_request_sd_flags(struct ldb_request *req, bool *explicit)
 206 {
 207         struct ldb_control *sd_control;
 208         uint32_t sd_flags = 0;
 209
 210         if (explicit) {
 211                 *explicit = false;
 212         }
 213
 214         sd_control = ldb_request_get_control(req, LDB_CONTROL_SD_FLAGS_OID);
 215         if (sd_control) {
 216                 struct ldb_sd_flags_control *sdctr = (struct ldb_sd_flags_control *)sd_control->data;
 217
 218                 sd_flags = sdctr->secinfo_flags;
 219
 220                 if (explicit) {
 221                         *explicit = true;
 222                 }
 223
 224                 /* mark it as handled */
 225                 sd_control->critical = 0;
 226         }
 227
 228         /* we only care for the last 4 bits */
 229         sd_flags &= 0x0000000F;
 230
 231         /*
 232          * MS-ADTS 3.1.1.3.4.1.11 says that no bits
 233          * equals all 4 bits
 234          */
 235         if (sd_flags == 0) {
 236                 sd_flags = 0xF;
 237         }
 238
 239         return sd_flags;
 240 }
 241
 242 int dsdb_module_schedule_sd_propagation(struct ldb_module *module,
 243                                         struct ldb_dn *nc_root,
 244                                         struct ldb_dn *dn,
 245                                         bool include_self)
 246 {
 247         struct ldb_context *ldb = ldb_module_get_ctx(module);
 248         struct dsdb_extended_sec_desc_propagation_op *op;
 249         int ret;
 250
 251         op = talloc_zero(module, struct dsdb_extended_sec_desc_propagation_op);
 252         if (op == NULL) {
 253                 return ldb_oom(ldb);
 254         }
 255
 256         op->nc_root = nc_root;
 257         op->dn = dn;
 258         op->include_self = include_self;
 259
 260         ret = dsdb_module_extended(module, op, NULL,
 261                                    DSDB_EXTENDED_SEC_DESC_PROPAGATION_OID,
 262                                    op,
 263                                    DSDB_FLAG_TOP_MODULE |
 264                                    DSDB_FLAG_AS_SYSTEM |
 265                                    DSDB_FLAG_TRUSTED,
 266                                    NULL);
 267         TALLOC_FREE(op);
 268         return ret;
 269 }