Advanced Security Options

In addition to traditional user and permission management, TDengine offers other security policies, such as IP whitelisting, audit logs, and data encryption, which are unique features of TDengine Enterprise. The whitelisting feature was first released in version 3.2.0.0, the audit logs in version 3.1.1.0, and database encryption in version 3.3.0.0. It is recommended to use the latest version.

IP Whitelisting

IP whitelisting is a network security technology that allows IT administrators to control "who" can access systems and resources, enhancing the security of database access and preventing external malicious attacks. IP whitelisting creates a list of trusted IP addresses, assigning them as unique identifiers for users, and only allows these IP addresses to access the target server. It is important to note that user permissions are independent of the IP whitelist and are managed separately. Below are the specific methods for configuring IP whitelisting.

The SQL to add an IP whitelist is as follows.

create user test pass password [sysinfo value] [host host_name1[,host_name2]] 
alter user test add host host_name1

The SQL to query the IP whitelist is as follows.

SELECT TEST, ALLOWED_HOST FROM INS_USERS;
SHOW USERS;

The command to delete an IP whitelist is as follows.

ALTER USER TEST DROP HOST HOST_NAME1

Audit Logs

TDengine records and manages user operations, then sends these as audit logs to taosKeeper, which saves them to any TDengine cluster. Administrators can use audit logs for security monitoring and historical tracing. The audit log feature in TDengine can be easily turned on or off by modifying the TDengine configuration file and restarting the service. The configuration for audit logs is described below.

taosd Configuration

Audit logs are generated by the database service taosd, and the corresponding parameters must be configured in the taos.cfg configuration file, as shown in the table below.

Parameter Name	Parameter Meaning
audit	Whether to enable audit logs, with a default value of 0. 1 to enable, 0 to disable
monitorFqdn	FQDN of the server where the taosKeeper receiving the audit logs is located
monitorPort	Port used by the taosKeeper service receiving the audit logs
monitorCompaction	Whether to compress data during reporting

taosKeeper Configuration

In the keeper.toml configuration file of taosKeeper, configure parameters related to audit logs, as shown in the table below.

Parameter Name	Parameter Meaning
auditDB	The name of the database for storing audit logs, with a default value of "audit". After receiving the reported audit logs, taosKeeper will check if this database exists; if it does not, it will create it automatically.

Data Format

The format of the reported audit logs is as follows:

{
    "ts": timestamp,
    "cluster_id": string,
    "user": string,
    "operation": string,
    "db": string,
    "resource": string,
    "client_add": string,
    "details": string
}

Table Structure

taosKeeper will automatically create a supertable in the corresponding database based on the reported audit data to store the data. The definition of this supertable is as follows:

CREATE STABLE operations(ts timestamp, details VARCHAR(64000), User VARCHAR(25), Operation VARCHAR(20), db VARCHAR(65), resource VARCHAR(193), client_add(25)) TAGS (clusterID VARCHAR(64));

Where:

1. db refers to the database involved in the operation, and resource refers to the resource involved in the operation.
2. User and Operation are data columns that indicate which user performed what operation on the object.
3. timestamp is the timestamp column indicating when the operation occurred.
4. details contains supplementary details about the operation, which is the SQL statement executed in most operations.
5. client_add refers to the client address, including IP and port.

Operation List

The current list of operations recorded in the audit logs and the meaning of each field in each operation is shown in the table below (Note: the meaning of the user field, timestamp field, and client_add is the same in all operations, so they are not included in the table).

Operation	Operation	DB	Resource	Details
create database	createDB	db name	NULL	SQL
alter database	alterDB	db name	NULL	SQL
drop database	dropDB	db name	NULL	SQL
create stable	createStb	db name	stable name	SQL
alter stable	alterStb	db name	stable name	SQL
drop stable	dropStb	db name	stable name	SQL
create user	createUser	NULL	User created	User property parameters (excluding password)
alter user	alterUser	NULL	User modified	Records modified parameters and new values for password changes (excluding password); other operations record SQL
drop user	dropUser	NULL	User deleted	SQL
create topic	createTopic	topic DB	Created topic name	SQL
drop topic	dropTopic	topic DB	Deleted topic name	SQL
create dnode	createDnode	NULL	IP:Port or FQDN:Port	SQL
drop dnode	dropDnode	NULL	dnodeId	SQL
alter dnode	alterDnode	NULL	dnodeId	SQL
create mnode	createMnode	NULL	dnodeId	SQL
drop mnode	dropMnode	NULL	dnodeId	SQL
create qnode	createQnode	NULL	dnodeId	SQL
drop qnode	dropQnode	NULL	dnodeId	SQL
login	login	NULL	NULL	appName
create stream	createStream	NULL	Created stream name	SQL
drop stream	dropStream	NULL	Deleted stream name	SQL
grant privileges	grantPrivileges	NULL	User granted	SQL
remove privileges	revokePrivileges	NULL	User revoked	SQL
compact database	compact	database name	NULL	SQL
balance vgroup leader	balanceVgroupLead	NULL	NULL	SQL
restore dnode	restoreDnode	NULL	dnodeId	SQL
redistribute vgroup	redistributeVgroup	NULL	vgroupId	SQL
balance vgroup	balanceVgroup	NULL	vgroupId	SQL
create table	createTable	db name	NULL	table name
drop table	dropTable	db name	NULL	table name

Viewing Audit Logs

After both taosd and taosKeeper are correctly configured and started, various operations in the system (as shown in the table above) will be recorded and reported in real-time as the system runs. Users can log into taosExplorer, click on "System Management" → "Audit" page to view the audit logs; they can also directly query the corresponding databases and tables in the TDengine CLI.

Data Encryption

TDengine supports Transparent Data Encryption (TDE), which encrypts static data files to prevent potential attackers from bypassing the database and directly reading sensitive information from the file system. The database access program is completely unaware of this; applications do not need any modifications or recompilation to work directly with the encrypted database, supporting encryption algorithms such as the national standard SM4. In transparent encryption, database key management and the scope of database encryption are two of the most important topics. TDengine encrypts the database key using machine codes, storing it locally rather than in a third-party manager. When data files are copied to other machines, the change in machine codes means the database key cannot be obtained, and thus the data files cannot be accessed. TDengine encrypts all data files, including write-ahead log files, metadata files, and time-series data files. After encryption, the data compression rate remains unchanged, and there is only a slight decrease in write and query performance.

Configuring Keys

Key configuration can be done in two ways: offline settings and online settings.

Method One: Offline Setting. You can configure keys separately for each node through offline settings, with the command as follows.

taosd -y {encryptKey}

Method Two: Online Setting. When all nodes in the cluster are online, you can use SQL to configure the keys, with the SQL as follows.

create encrypt_key {encryptKey};

The online setting method requires that all nodes that have joined the cluster have not used the offline setting method to generate keys; otherwise, the online setting will fail. Successfully setting the online key will also automatically load and use the key.

Creating Encrypted Databases

TDengine supports creating encrypted databases via SQL, with the SQL as follows.

create database [if not exists] db_name [database_options]
database_options:
 database_option ...
database_option: {
 encrypt_algorithm {'none' |'sm4'}
}

The main parameters are described as follows.

• encrypt_algorithm: Specifies the encryption algorithm used for data. The default is none, meaning no encryption. sm4 indicates the use of the SM4 encryption algorithm.

Viewing Encryption Configuration

Users can query the current encryption configuration of databases by querying the system database ins_databases, with the SQL as follows.

select name, `encrypt_algorithm` from ins_databases;
              name              | encrypt_algorithm |
=====================================================
 power1                         | none              |
 power                          | sm4               |

Viewing Node Key Status

You can check the node key status with the following SQL command:

show encryptions;

select * from information_schema.ins_encryptions;
  dnode_id   |           key_status           |
===============================================
           1 | loaded                         |
           2 | unset                          |
           3 | unknown                        |

The key_status has three possible values:

• When a node has not set a key, the status column displays unset.
• When the key is successfully validated and loaded, the status column displays loaded.
• When the node is not started, and the key's status cannot be determined, the status column displays unknown.

Updating Key Configuration

When the hardware configuration of a node changes, you need to update the key using the following command, which is the same as the offline configuration command:

taosd -y  {encryptKey}

To update the key configuration, you must first stop taosd, and use exactly the same key; that is, the key cannot be modified after the database is created.