TODO this could be wrong, but NULL also...? dsdb-acl: pass the object type to dsdb_mo...
[metze/samba/wip.git] / source4 / dsdb / samdb / ldb_modules / acl_read.c
index 0e9de9adec4c6651c8d10c8fe4599f1caa9a65b8..520be86c1908efa56e91921f8946e1b3f407cb1a 100644 (file)
@@ -44,139 +44,266 @@ struct aclread_context {
        struct ldb_request *req;
        const char * const *attrs;
        const struct dsdb_schema *schema;
-       bool sd;
-       bool instance_type;
-       bool object_sid;
+       uint32_t sd_flags;
+       bool added_nTSecurityDescriptor;
+       bool added_instanceType;
+       bool added_objectSid;
+       bool added_objectClass;
+       bool indirsync;
 };
 
 struct aclread_private {
        bool enabled;
 };
 
+static void aclread_mark_inaccesslible(struct ldb_message_element *el) {
+       el->flags |= LDB_FLAG_INTERNAL_INACCESSIBLE_ATTRIBUTE;
+}
+
+static bool aclread_is_inaccessible(struct ldb_message_element *el) {
+       return el->flags & LDB_FLAG_INTERNAL_INACCESSIBLE_ATTRIBUTE;
+}
+
 static int aclread_callback(struct ldb_request *req, struct ldb_reply *ares)
 {
-        struct ldb_context *ldb;
-        struct aclread_context *ac;
-        struct ldb_result *acl_res;
-        struct ldb_message_element *parent;
-        static const char *acl_attrs[] = {
-                "nTSecurityDescriptor",
-                "objectSid",
-                "insyanceType",
-                NULL
-        };
-        int ret;
-        unsigned int i;
-        struct security_descriptor *sd;
-        struct dom_sid *sid = NULL;
-        TALLOC_CTX *tmp_ctx;
-        uint32_t instanceType;
-
-        ac = talloc_get_type(req->context, struct aclread_context);
-        ldb = ldb_module_get_ctx(ac->module);
-        if (!ares) {
-                return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR );
-        }
-        if (ares->error != LDB_SUCCESS) {
-                return ldb_module_done(ac->req, ares->controls,
-                                       ares->response, ares->error);
-        }
-        tmp_ctx = talloc_new(ac);
-        switch (ares->type) {
-        case LDB_REPLY_ENTRY:
-                ret = dsdb_get_sd_from_ldb_message(ldb, tmp_ctx, ares->message, &sd);
-                if (ret != LDB_SUCCESS) {
-                        DEBUG(10, ("acl_read: cannot get descriptor\n"));
-                        ret = LDB_ERR_OPERATIONS_ERROR;
-                        goto fail;
-                }
-                sid = samdb_result_dom_sid(tmp_ctx, ares->message, "objectSid");
-                /* get the object instance type */
-                instanceType = ldb_msg_find_attr_as_uint(ares->message,
+       struct ldb_context *ldb;
+       struct aclread_context *ac;
+       struct ldb_message *ret_msg;
+       struct ldb_message *msg;
+       int ret, num_of_attrs = 0;
+       unsigned int i, k = 0;
+       struct security_descriptor *sd;
+       struct dom_sid *sid = NULL;
+       TALLOC_CTX *tmp_ctx;
+       uint32_t instanceType;
+       const struct dsdb_class *objectclass;
+
+       ac = talloc_get_type(req->context, struct aclread_context);
+       ldb = ldb_module_get_ctx(ac->module);
+       if (!ares) {
+               return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR );
+       }
+       if (ares->error != LDB_SUCCESS) {
+               return ldb_module_done(ac->req, ares->controls,
+                                      ares->response, ares->error);
+       }
+       tmp_ctx = talloc_new(ac);
+       switch (ares->type) {
+       case LDB_REPLY_ENTRY:
+               msg = ares->message;
+               ret = dsdb_get_sd_from_ldb_message(ldb, tmp_ctx, msg, &sd);
+               if (ret != LDB_SUCCESS || sd == NULL ) {
+                       ldb_debug_set(ldb, LDB_DEBUG_FATAL,
+                                     "acl_read: cannot get descriptor of %s\n",
+                                     ldb_dn_get_linearized(msg->dn));
+                       ret = LDB_ERR_OPERATIONS_ERROR;
+                       goto fail;
+               }
+               /*
+                * Get the most specific structural object class for the ACL check
+                */
+               objectclass = dsdb_get_structural_oc_from_msg(ac->schema, msg);
+               if (objectclass == NULL) {
+                       ldb_asprintf_errstring(ldb, "acl_read: Failed to find a structural class for %s",
+                                              ldb_dn_get_linearized(msg->dn));
+                       ret = LDB_ERR_OPERATIONS_ERROR;
+                       goto fail;
+               }
+
+               sid = samdb_result_dom_sid(tmp_ctx, msg, "objectSid");
+               /* get the object instance type */
+               instanceType = ldb_msg_find_attr_as_uint(msg,
                                                         "instanceType", 0);
-                if (!ldb_dn_is_null(ares->message->dn) && !(instanceType & INSTANCE_TYPE_IS_NC_HEAD))
-                {
+               if (!ldb_dn_is_null(msg->dn) && !(instanceType & INSTANCE_TYPE_IS_NC_HEAD))
+               {
                        /* the object has a parent, so we have to check for visibility */
-                       struct ldb_dn *parent_dn = ldb_dn_get_parent(tmp_ctx, ares->message->dn);
+                       struct ldb_dn *parent_dn = ldb_dn_get_parent(tmp_ctx, msg->dn);
+
                        ret = dsdb_module_check_access_on_dn(ac->module,
                                                             tmp_ctx,
                                                             parent_dn,
                                                             SEC_ADS_LIST,
-                                                            NULL);
+                                                            &objectclass->schemaIDGUID,
+                                                            req);
                        if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
                                talloc_free(tmp_ctx);
                                return LDB_SUCCESS;
                        } else if (ret != LDB_SUCCESS) {
+                               ldb_debug_set(ldb, LDB_DEBUG_FATAL,
+                                             "acl_read: %s check parent %s - %s\n",
+                                             ldb_dn_get_linearized(msg->dn),
+                                             ldb_strerror(ret),
+                                             ldb_errstring(ldb));
+                               goto fail;
+                       }
+               }
+
+               /* for every element in the message check RP */
+               for (i=0; i < msg->num_elements; i++) {
+                       const struct dsdb_attribute *attr;
+                       bool is_sd, is_objectsid, is_instancetype, is_objectclass;
+                       uint32_t access_mask;
+                       attr = dsdb_attribute_by_lDAPDisplayName(ac->schema,
+                                                                msg->elements[i].name);
+                       if (!attr) {
+                               ldb_debug_set(ldb, LDB_DEBUG_FATAL,
+                                             "acl_read: %s cannot find attr[%s] in of schema\n",
+                                             ldb_dn_get_linearized(msg->dn),
+                                             msg->elements[i].name);
+                               ret = LDB_ERR_OPERATIONS_ERROR;
+                               goto fail;
+                       }
+                       is_sd = ldb_attr_cmp("nTSecurityDescriptor",
+                                             msg->elements[i].name) == 0;
+                       is_objectsid = ldb_attr_cmp("objectSid",
+                                                   msg->elements[i].name) == 0;
+                       is_instancetype = ldb_attr_cmp("instanceType",
+                                                      msg->elements[i].name) == 0;
+                       is_objectclass = ldb_attr_cmp("objectClass",
+                                                     msg->elements[i].name) == 0;
+                       /* these attributes were added to perform access checks and must be removed */
+                       if (is_objectsid && ac->added_objectSid) {
+                               aclread_mark_inaccesslible(&msg->elements[i]);
+                               continue;
+                       }
+                       if (is_instancetype && ac->added_instanceType) {
+                               aclread_mark_inaccesslible(&msg->elements[i]);
+                               continue;
+                       }
+                       if (is_objectclass && ac->added_objectClass) {
+                               aclread_mark_inaccesslible(&msg->elements[i]);
+                               continue;
+                       }
+                       if (is_sd && ac->added_nTSecurityDescriptor) {
+                               aclread_mark_inaccesslible(&msg->elements[i]);
+                               continue;
+                       }
+                       /* nTSecurityDescriptor is a special case */
+                       if (is_sd) {
+                               access_mask = 0;
+
+                               if (ac->sd_flags & (SECINFO_OWNER|SECINFO_GROUP)) {
+                                       access_mask |= SEC_STD_READ_CONTROL;
+                               }
+                               if (ac->sd_flags & SECINFO_DACL) {
+                                       access_mask |= SEC_STD_READ_CONTROL;
+                               }
+                               if (ac->sd_flags & SECINFO_SACL) {
+                                       access_mask |= SEC_FLAG_SYSTEM_SECURITY;
+                               }
+                       } else {
+                               access_mask = SEC_ADS_READ_PROP;
+                       }
+
+                       if (attr->searchFlags & SEARCH_FLAG_CONFIDENTIAL) {
+                               access_mask |= SEC_ADS_CONTROL_ACCESS;
+                       }
+
+                       if (access_mask == 0) {
+                               aclread_mark_inaccesslible(&msg->elements[i]);
+                               continue;
+                       }
+
+                       ret = acl_check_access_on_attribute(ac->module,
+                                                           tmp_ctx,
+                                                           sd,
+                                                           sid,
+                                                           access_mask,
+                                                           attr,
+                                                           objectclass);
+
+                       /*
+                        * Dirsync control needs the replpropertymetadata attribute
+                        * so return it as it will be removed by the control
+                        * in anycase.
+                        */
+                       if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
+                               if (!ac->indirsync) {
+                                       /*
+                                        * do not return this entry if attribute is
+                                        * part of the search filter
+                                        */
+                                       if (dsdb_attr_in_parse_tree(ac->req->op.search.tree,
+                                                               msg->elements[i].name)) {
+                                               talloc_free(tmp_ctx);
+                                               return LDB_SUCCESS;
+                                       }
+                                       aclread_mark_inaccesslible(&msg->elements[i]);
+                               } else {
+                                       /*
+                                        * We are doing dirysnc answers
+                                        * and the object shouldn't be returned (normally)
+                                        * but we will return it without replPropertyMetaData
+                                        * so that the dirysync module will do what is needed
+                                        * (remove the object if it is not deleted, or return
+                                        * just the objectGUID if it's deleted).
+                                        */
+                                       if (dsdb_attr_in_parse_tree(ac->req->op.search.tree,
+                                                               msg->elements[i].name)) {
+                                               ldb_msg_remove_attr(msg, "replPropertyMetaData");
+                                               break;
+                                       } else {
+                                               aclread_mark_inaccesslible(&msg->elements[i]);
+                                       }
+                               }
+                       } else if (ret != LDB_SUCCESS) {
+                               ldb_debug_set(ldb, LDB_DEBUG_FATAL,
+                                             "acl_read: %s check attr[%s] gives %s - %s\n",
+                                             ldb_dn_get_linearized(msg->dn),
+                                             msg->elements[i].name,
+                                             ldb_strerror(ret),
+                                             ldb_errstring(ldb));
                                goto fail;
                        }
-                }
-                /* for every element in the message check RP */
-                i = 0;
-                while (i < ares->message->num_elements) {
-                        const struct dsdb_attribute *attr;
-                        attr =  dsdb_attribute_by_lDAPDisplayName(ac->schema,
-                                                                  ares->message->elements[i].name);
-                        if (!attr) {
-                                DEBUG(2, ("acl_read: cannot find attribute %s in schema\n",
-                                          ares->message->elements[i].name));
-                                ret = LDB_ERR_OPERATIONS_ERROR;
-                                goto fail;
-                        }
-                        /* nTSecurityDescriptor is a special case */
-                        if (ldb_attr_cmp("nTSecurityDescriptor",
-                                         ares->message->elements[i].name) == 0) {
-                                if (ac->sd) {
-                                        ldb_msg_remove_attr(ares->message, ares->message->elements[i].name);
-                                        ret = LDB_SUCCESS;
-                                }
-                                ret = acl_check_access_on_attribute(ac->module,
-                                                                    tmp_ctx,
-                                                                    sd,
-                                                                    sid,
-                                                                    SEC_FLAG_SYSTEM_SECURITY|SEC_STD_READ_CONTROL,
-                                                                    attr);
-                        } else {
-                                ret = acl_check_access_on_attribute(ac->module,
-                                                                    tmp_ctx,
-                                                                    sd,
-                                                                    sid,
-                                                                    SEC_ADS_READ_PROP,
-                                                                    attr);
-                        }
-                        if (ret == LDB_SUCCESS) {
-                                i++;
-                        } else if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
-                                /* do not return this entry if attribute is
-                                           part of the search filter */
-                                if (dsdb_attr_in_parse_tree(ac->req->op.search.tree,
-                                                            ares->message->elements[i].name)) {
-                                        talloc_free(tmp_ctx);
-                                        return LDB_SUCCESS;
-                                }
-                                ldb_msg_remove_attr(ares->message, ares->message->elements[i].name);
-                        } else {
-                                goto fail;
-                        }
-                }
-                if (ac->instance_type) {
-                        ldb_msg_remove_attr(ares->message, "instanceType");
-                }
-                if (ac->object_sid) {
-                        ldb_msg_remove_attr(ares->message, "objectSid");
-                }
-                talloc_free(tmp_ctx);
-                return ldb_module_send_entry(ac->req, ares->message, ares->controls);
-        case LDB_REPLY_REFERRAL:
-                return ldb_module_send_referral(ac->req, ares->referral);
-        case LDB_REPLY_DONE:
-                return ldb_module_done(ac->req, ares->controls,
+               }
+               for (i=0; i < msg->num_elements; i++) {
+                       if (!aclread_is_inaccessible(&msg->elements[i])) {
+                               num_of_attrs++;
+                       }
+               }
+               /*create a new message to return*/
+               ret_msg = ldb_msg_new(ac->req);
+               ret_msg->dn = msg->dn;
+               talloc_steal(ret_msg, msg->dn);
+               ret_msg->num_elements = num_of_attrs;
+               if (num_of_attrs > 0) {
+                       ret_msg->elements = talloc_array(ret_msg,
+                                                        struct ldb_message_element,
+                                                        num_of_attrs);
+                       if (ret_msg->elements == NULL) {
+                               return ldb_oom(ldb);
+                       }
+                       for (i=0; i < msg->num_elements; i++) {
+                               bool to_remove = aclread_is_inaccessible(&msg->elements[i]);
+                               if (!to_remove) {
+                                       ret_msg->elements[k] = msg->elements[i];
+                                       talloc_steal(ret_msg->elements, msg->elements[i].name);
+                                       talloc_steal(ret_msg->elements, msg->elements[i].values);
+                                       k++;
+                               }
+                       }
+                       /*
+                        * This should not be needed, but some modules
+                        * may allocate values on the wrong context...
+                        */
+                       talloc_steal(ret_msg->elements, msg);
+               } else {
+                       ret_msg->elements = NULL;
+               }
+               talloc_free(tmp_ctx);
+
+               return ldb_module_send_entry(ac->req, ret_msg, ares->controls);
+       case LDB_REPLY_REFERRAL:
+               return ldb_module_send_referral(ac->req, ares->referral);
+       case LDB_REPLY_DONE:
+               return ldb_module_done(ac->req, ares->controls,
                                        ares->response, LDB_SUCCESS);
 
-        }
-        return LDB_SUCCESS;
+       }
+       return LDB_SUCCESS;
 fail:
-        talloc_free(tmp_ctx);
-        return ldb_module_done(ac->req, NULL, NULL, ret);
+       talloc_free(tmp_ctx);
+       return ldb_module_done(ac->req, NULL, NULL, ret);
 }
 
 
@@ -187,14 +314,19 @@ static int aclread_search(struct ldb_module *module, struct ldb_request *req)
        struct aclread_context *ac;
        struct ldb_request *down_req;
        struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+       uint32_t flags = ldb_req_get_custom_flags(req);
        struct ldb_result *res;
        struct aclread_private *p;
+       bool need_sd = false;
+       bool explicit_sd_flags = false;
        bool is_untrusted = ldb_req_is_untrusted(req);
+       static const char * const _all_attrs[] = { "*", NULL };
+       bool all_attrs = false;
        const char * const *attrs = NULL;
        uint32_t instanceType;
        static const char *acl_attrs[] = {
-                "instanceType",
-                NULL
+               "instanceType",
+               NULL
        };
 
        ldb = ldb_module_get_ctx(module);
@@ -217,13 +349,15 @@ static int aclread_search(struct ldb_module *module, struct ldb_request *req)
                ret = dsdb_module_search_dn(module, req, &res, req->op.search.base,
                                            acl_attrs,
                                            DSDB_FLAG_NEXT_MODULE |
-                                           DSDB_SEARCH_SHOW_DELETED);
+                                           DSDB_FLAG_AS_SYSTEM |
+                                           DSDB_SEARCH_SHOW_RECYCLED,
+                                           req);
                if (ret != LDB_SUCCESS) {
                        return ldb_error(ldb, ret,
-                                        "acl_read: Error retrieving instanceType for base.");
+                                       "acl_read: Error retrieving instanceType for base.");
                }
                instanceType = ldb_msg_find_attr_as_uint(res->msgs[0],
-                                                        "instanceType", 0);
+                                                       "instanceType", 0);
                if (instanceType != 0 && !(instanceType & INSTANCE_TYPE_IS_NC_HEAD))
                {
                        /* the object has a parent, so we have to check for visibility */
@@ -232,7 +366,7 @@ static int aclread_search(struct ldb_module *module, struct ldb_request *req)
                                                             req,
                                                             parent_dn,
                                                             SEC_ADS_LIST,
-                                                            NULL);
+                                                            NULL, req);
                        if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
                                return ldb_module_done(req, NULL, NULL, LDB_ERR_NO_SUCH_OBJECT);
                        } else if (ret != LDB_SUCCESS) {
@@ -247,31 +381,73 @@ static int aclread_search(struct ldb_module *module, struct ldb_request *req)
        ac->module = module;
        ac->req = req;
        ac->schema = dsdb_get_schema(ldb, req);
+       if (flags & DSDB_ACL_CHECKS_DIRSYNC_FLAG) {
+               ac->indirsync = true;
+       } else {
+               ac->indirsync = false;
+       }
        if (!ac->schema) {
                return ldb_operr(ldb);
        }
-       ac->sd = !(ldb_attr_in_list(req->op.search.attrs, "nTSecurityDescriptor"));
-       if (req->op.search.attrs && !ldb_attr_in_list(req->op.search.attrs, "*")) {
-               if (!ldb_attr_in_list(req->op.search.attrs, "instanceType")) {
-                       ac->instance_type = true;
-                       attrs = ldb_attr_list_copy_add(ac, req->op.search.attrs, "instanceType");
-               } else {
-                       attrs = req->op.search.attrs;
+
+       attrs = req->op.search.attrs;
+       if (attrs == NULL) {
+               all_attrs = true;
+               attrs = _all_attrs;
+       } else if (attrs[0] == NULL) {
+               all_attrs = true;
+               attrs = _all_attrs;
+       } else if (ldb_attr_in_list(attrs, "*")) {
+               all_attrs = true;
+       }
+
+       /*
+        * In theory we should also check for the SD control but control verification is
+        * expensive so we'd better had the ntsecuritydescriptor to the list of
+        * searched attribute and then remove it !
+        */
+       ac->sd_flags = dsdb_request_sd_flags(ac->req, &explicit_sd_flags);
+
+       if (ldb_attr_in_list(attrs, "nTSecurityDescriptor")) {
+               need_sd = false;
+       } else if (explicit_sd_flags && all_attrs) {
+               need_sd = false;
+       } else {
+               need_sd = true;
+       }
+
+       if (!all_attrs) {
+               if (!ldb_attr_in_list(attrs, "instanceType")) {
+                       attrs = ldb_attr_list_copy_add(ac, attrs, "instanceType");
+                       if (attrs == NULL) {
+                               return ldb_oom(ldb);
+                       }
+                       ac->added_instanceType = true;
                }
                if (!ldb_attr_in_list(req->op.search.attrs, "objectSid")) {
-                       ac->object_sid = true;
                        attrs = ldb_attr_list_copy_add(ac, attrs, "objectSid");
+                       if (attrs == NULL) {
+                               return ldb_oom(ldb);
+                       }
+                       ac->added_objectSid = true;
+               }
+               if (!ldb_attr_in_list(req->op.search.attrs, "objectClass")) {
+                       attrs = ldb_attr_list_copy_add(ac, attrs, "objectClass");
+                       if (attrs == NULL) {
+                               return ldb_oom(ldb);
+                       }
+                       ac->added_objectClass = true;
                }
        }
 
-       if (ac->sd) {
-               /* avoid replacing all attributes with nTSecurityDescriptor
-                * if attribute list is empty */
-               if (!attrs) {
-                       attrs = ldb_attr_list_copy_add(ac, attrs, "*");
-               }
+       if (need_sd) {
                attrs = ldb_attr_list_copy_add(ac, attrs, "nTSecurityDescriptor");
+               if (attrs == NULL) {
+                       return ldb_oom(ldb);
+               }
+               ac->added_nTSecurityDescriptor = true;
        }
+
        ac->attrs = req->op.search.attrs;
        ret = ldb_build_search_req_ex(&down_req,
                                      ldb, ac,
@@ -297,7 +473,7 @@ static int aclread_init(struct ldb_module *module)
        if (p == NULL) {
                return ldb_module_oom(module);
        }
-       p->enabled = lpcfg_parm_bool(ldb_get_opaque(ldb, "loadparm"), NULL, "acl", "search", false);
+       p->enabled = lpcfg_parm_bool(ldb_get_opaque(ldb, "loadparm"), NULL, "acl", "search", true);
        ldb_module_set_private(module, p);
        return ldb_next_init(module);
 }