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 {
  60         int ret;
  61         struct ldb_result *acl_res;
  62         static const char *acl_attrs[] = {
  63                 "nTSecurityDescriptor",
  64                 "objectSid",
  65                 NULL
  66         };
  67         struct ldb_context *ldb = ldb_module_get_ctx(module);
  68         struct auth_session_info *session_info
  69                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
  70         if(!session_info) {
  71                 return ldb_operr(ldb);
  72         }
  73         ret = dsdb_module_search_dn(module, mem_ctx, &acl_res, dn,
  74                                     acl_attrs,
  75                                     DSDB_FLAG_NEXT_MODULE |
  76                                     DSDB_SEARCH_SHOW_RECYCLED);
  77         if (ret != LDB_SUCCESS) {
  78                 DEBUG(0,("access_check: failed to find object %s\n", ldb_dn_get_linearized(dn)));
  79                 return ret;
  80         }
  81         return dsdb_check_access_on_dn_internal(ldb, acl_res,
  82                                                 mem_ctx,
  83                                                 session_info->security_token,
  84                                                 dn,
  85                                                 access_mask,
  86                                                 guid);
  87 }
  88
  89 int dsdb_module_check_access_on_guid(struct ldb_module *module,
  90                                      TALLOC_CTX *mem_ctx,
  91                                      struct GUID *guid,
  92                                      uint32_t access_mask,
  93                                      const struct GUID *oc_guid)
  94 {
  95         int ret;
  96         struct ldb_result *acl_res;
  97         static const char *acl_attrs[] = {
  98                 "nTSecurityDescriptor",
  99                 "objectSid",
 100                 NULL
 101         };
 102         struct ldb_context *ldb = ldb_module_get_ctx(module);
 103         struct auth_session_info *session_info
 104                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
 105         if(!session_info) {
 106                 return ldb_operr(ldb);
 107         }
 108         ret = dsdb_module_search(module, mem_ctx, &acl_res, NULL, LDB_SCOPE_SUBTREE,
 109                                  acl_attrs,
 110                                  DSDB_FLAG_NEXT_MODULE |
 111                                  DSDB_SEARCH_SHOW_RECYCLED,
 112                                  "objectGUID=%s", GUID_string(mem_ctx, guid));
 113
 114         if (ret != LDB_SUCCESS || acl_res->count == 0) {
 115                 DEBUG(0,("access_check: failed to find object %s\n", GUID_string(mem_ctx, guid)));
 116                 return ret;
 117         }
 118         return dsdb_check_access_on_dn_internal(ldb, acl_res,
 119                                                 mem_ctx,
 120                                                 session_info->security_token,
 121                                                 acl_res->msgs[0]->dn,
 122                                                 access_mask,
 123                                                 oc_guid);
 124 }
 125
 126 int acl_check_access_on_attribute(struct ldb_module *module,
 127                                   TALLOC_CTX *mem_ctx,
 128                                   struct security_descriptor *sd,
 129                                   struct dom_sid *rp_sid,
 130                                   uint32_t access_mask,
 131                                   const struct dsdb_attribute *attr)
 132 {
 133         int ret;
 134         NTSTATUS status;
 135         uint32_t access_granted;
 136         struct object_tree *root = NULL;
 137         struct object_tree *new_node = NULL;
 138         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 139         struct security_token *token = acl_user_token(module);
 140         if (attr) {
 141                 if (!GUID_all_zero(&attr->attributeSecurityGUID)) {
 142                         if (!insert_in_object_tree(tmp_ctx,
 143                                                    &attr->attributeSecurityGUID,
 144                                                    access_mask, &root,
 145                                                    &new_node)) {
 146                                 DEBUG(10, ("acl_search: cannot add to object tree securityGUID\n"));
 147                                 goto fail;
 148                         }
 149
 150                         if (!insert_in_object_tree(tmp_ctx,
 151                                                    &attr->schemaIDGUID,
 152                                                    access_mask, &new_node,
 153                                                    &new_node)) {
 154                                 DEBUG(10, ("acl_search: cannot add to object tree attributeGUID\n"));
 155                                 goto fail;
 156                         }
 157                 }
 158                 else {
 159                         if (!insert_in_object_tree(tmp_ctx,
 160                                                    &attr->schemaIDGUID,
 161                                                    access_mask, &root,
 162                                                    &new_node)) {
 163                                 DEBUG(10, ("acl_search: cannot add to object tree attributeGUID\n"));
 164                                 goto fail;
 165                         }
 166                 }
 167         }
 168         status = sec_access_check_ds(sd, token,
 169                                      access_mask,
 170                                      &access_granted,
 171                                      root,
 172                                      rp_sid);
 173         if (!NT_STATUS_IS_OK(status)) {
 174                 ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 175         }
 176         else {
 177                 ret = LDB_SUCCESS;
 178         }
 179         talloc_free(tmp_ctx);
 180         return ret;
 181 fail:
 182         talloc_free(tmp_ctx);
 183         return ldb_operr(ldb_module_get_ctx(module));
 184 }
 185
 186
 187 /* checks for validated writes */
 188 int acl_check_extended_right(TALLOC_CTX *mem_ctx,
 189                              struct security_descriptor *sd,
 190                              struct security_token *token,
 191                              const char *ext_right,
 192                              uint32_t right_type,
 193                              struct dom_sid *sid)
 194 {
 195         struct GUID right;
 196         NTSTATUS status;
 197         uint32_t access_granted;
 198         struct object_tree *root = NULL;
 199         struct object_tree *new_node = NULL;
 200         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 201
 202         GUID_from_string(ext_right, &right);
 203
 204         if (!insert_in_object_tree(tmp_ctx, &right, right_type,
 205                                    &root, &new_node)) {
 206                 DEBUG(10, ("acl_ext_right: cannot add to object tree\n"));
 207                 talloc_free(tmp_ctx);
 208                 return LDB_ERR_OPERATIONS_ERROR;
 209         }
 210         status = sec_access_check_ds(sd, token,
 211                                      right_type,
 212                                      &access_granted,
 213                                      root,
 214                                      sid);
 215
 216         if (!NT_STATUS_IS_OK(status)) {
 217                 talloc_free(tmp_ctx);
 218                 return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 219         }
 220         talloc_free(tmp_ctx);
 221         return LDB_SUCCESS;
 222 }
 223
 224 const char *acl_user_name(TALLOC_CTX *mem_ctx, struct ldb_module *module)
 225 {
 226         struct ldb_context *ldb = ldb_module_get_ctx(module);
 227         struct auth_session_info *session_info
 228                 = (struct auth_session_info *)ldb_get_opaque(ldb, "sessionInfo");
 229         if (!session_info) {
 230                 return "UNKNOWN (NULL)";
 231         }
 232
 233         return talloc_asprintf(mem_ctx, "%s\\%s",
 234                                session_info->server_info->domain_name,
 235                                session_info->server_info->account_name);
 236 }