- Introduction
- Concepts
- Architecture
- Key Features
- Horizontal Scalability
- MySQL Compatible Syntax
- Replicate from and to MySQL
- Distributed Transactions with Strong Consistency
- Cloud Native Architecture
- Minimize ETL with HTAP
- Fault Tolerance & Recovery with Raft
- Automatic Rebalancing
- Deployment and Orchestration with Ansible, Kubernetes, Docker
- JSON Support
- Spark Integration
- Read Historical Data Without Restoring from Backup
- Fast Import and Restore of Data
- Hybrid of Column and Row Storage
- SQL Plan Management
- Open Source
- Online Schema Changes
- How-to
- Get Started
- Deploy
- Hardware Recommendations
- From Binary Tarball
- Orchestrated Deployment
- Geographic Redundancy
- Data Migration with Ansible
- Configure
- Secure
- Transport Layer Security (TLS)
- Generate Self-signed Certificates
- Monitor
- Migrate
- Maintain
- Common Ansible Operations
- Backup and Restore
- Use BR (recommended)
- Identify Abnormal Queries
- Scale
- Upgrade
- Troubleshoot
- Reference
- SQL
- MySQL Compatibility
- SQL Language Structure
- Attributes
- Data Types
- Functions and Operators
- Function and Operator Reference
- Type Conversion in Expression Evaluation
- Operators
- Control Flow Functions
- String Functions
- Numeric Functions and Operators
- Date and Time Functions
- Bit Functions and Operators
- Cast Functions and Operators
- Encryption and Compression Functions
- Information Functions
- JSON Functions
- Aggregate (GROUP BY) Functions
- Window Functions
- Miscellaneous Functions
- Precision Math
- List of Expressions for Pushdown
- SQL Statements
ADD COLUMN
ADD INDEX
ADMIN
ADMIN CANCEL DDL
ADMIN CHECKSUM TABLE
ADMIN CHECK [TABLE|INDEX]
ADMIN SHOW DDL [JOBS|QUERIES]
ALTER DATABASE
ALTER INSTANCE
ALTER TABLE
ALTER USER
ANALYZE TABLE
BEGIN
CHANGE COLUMN
COMMIT
CREATE DATABASE
CREATE INDEX
CREATE ROLE
CREATE TABLE LIKE
CREATE TABLE
CREATE USER
CREATE VIEW
DEALLOCATE
DELETE
DESC
DESCRIBE
DO
DROP COLUMN
DROP DATABASE
DROP INDEX
DROP ROLE
DROP TABLE
DROP USER
DROP VIEW
EXECUTE
EXPLAIN ANALYZE
EXPLAIN
FLUSH PRIVILEGES
FLUSH STATUS
FLUSH TABLES
GRANT <privileges>
GRANT <role>
INSERT
KILL [TIDB]
LOAD DATA
LOAD STATS
MODIFY COLUMN
PREPARE
RECOVER TABLE
RENAME INDEX
RENAME TABLE
REPLACE
REVOKE <privileges>
REVOKE <role>
ROLLBACK
SELECT
SET DEFAULT ROLE
SET [NAMES|CHARACTER SET]
SET PASSWORD
SET ROLE
SET TRANSACTION
SET [GLOBAL|SESSION] <variable>
SHOW ANALYZE STATUS
SHOW CHARACTER SET
SHOW COLLATION
SHOW [FULL] COLUMNS FROM
SHOW CREATE TABLE
SHOW CREATE USER
SHOW DATABASES
SHOW ENGINES
SHOW ERRORS
SHOW [FULL] FIELDS FROM
SHOW GRANTS
SHOW INDEXES [FROM|IN]
SHOW INDEX [FROM|IN]
SHOW KEYS [FROM|IN]
SHOW PRIVILEGES
SHOW [FULL] PROCESSSLIST
SHOW SCHEMAS
SHOW STATUS
SHOW [FULL] TABLES
SHOW TABLE REGIONS
SHOW TABLE STATUS
SHOW [GLOBAL|SESSION] VARIABLES
SHOW WARNINGS
SPLIT REGION
START TRANSACTION
TRACE
TRUNCATE
UPDATE
USE
- Constraints
- Generated Columns
- Partitioning
- Character Set
- SQL Mode
- Views
- Configuration
- Security
- Transactions
- System Databases
- Errors Codes
- Supported Client Drivers
- Garbage Collection (GC)
- Performance
- Overview
- Understanding the Query Execution Plan
- The Blocklist of Optimization Rules and Expression Pushdown
- Introduction to Statistics
- TopN and Limit Push Down
- Optimizer Hints
- Follower Read
- Check the TiDB Cluster Status Using SQL Statements
- Execution Plan Binding
- Statement Summary Table
- Tune TiKV
- Operating System Tuning
- Column Pruning
- Key Monitoring Metrics
- Alert Rules
- Best Practices
- TiSpark
- TiKV
- TiFlash
- TiDB Binlog
- Tools
- Overview
- Use Cases
- Download
- TiDB Operator
- Table Filter
- Backup & Restore (BR)
- Mydumper
- Syncer
- Loader
- Data Migration
- TiDB Lightning
- sync-diff-inspector
- PD Control
- PD Recover
- TiKV Control
- TiDB Control
- TiDB in Kubernetes
- FAQs
- Support
- Contribute
- Releases
- All Releases
- v3.1
- v3.0
- v2.1
- v2.0
- v1.0
- Glossary
You are viewing the documentation of an older version of the TiDB database (TiDB v3.1).
Enable TLS for MySQL Clients
It is recommended to use the encrypted connection to ensure data security because non-encrypted connection might lead to an information leak.
The TiDB server supports the encrypted connection based on the TLS (Transport Layer Security). The protocol is consistent with MySQL encrypted connections and is directly supported by existing MySQL clients such as MySQL operation tools and MySQL drivers. TLS is sometimes referred to as SSL (Secure Sockets Layer). Because the SSL protocol has known security vulnerabilities, TiDB does not support it. TiDB supports the following versions: TLS 1.0, TLS 1.1, and TLS 1.2, TLS 1.3.
After using an encrypted connection, the connection has the following security properties:
- Confidentiality: the traffic plaintext cannot be eavesdropped
- Integrity: the traffic plaintext cannot be tampered
- Authentication: (optional) the client and the server can verify the identity of both parties to avoid man-in-the-middle attacks
The encrypted connections in TiDB are disabled by default. To use encrypted connections in the client, you must first configure the TiDB server and enable encrypted connections. In short, to use encrypted connections, both of the following conditions must be met:
- Enable encrypted connections in the TiDB server.
- The client specifies to use an encrypted connection.
Similar to MySQL, the encrypted connections in TiDB consist of single connections. The encrypted connection is optional by default. For a TiDB server with encrypted connections enabled, you can choose to securely connect to the TiDB server through an encrypted connection, or to use a generally unencrypted connection. If the encrypted connections are enforced as required, both of the following two ways are available:
Configure the launch parameter
--require-secure-transport
to enable encrypted connections to the TiDB server for all users.Specify
require ssl
when you create a user (create user
), grant permissions (grant
) or modify an existing user (alter user
), which is to specify that specified users must use the encrypted connection to access TiDB. The following is an example of creating a user:create user 'u1'@'%' require ssl;
If the login user has configured using the TiDB Certificate-Based Authentication for Login, the user is implicitly required to enable the encrypted connection to TiDB.
Configure TiDB to use encrypted connections
See the following desrciptions about the related parameters to enable encrypted connections:
ssl-cert
: specifies the file path of the SSL certificatessl-key
: specifies the private key that matches the certificatessl-ca
: (optional) specifies the file path of the trusted CA certificate
To enable encrypted connections in the TiDB server, you must specify both of the ssl-cert
and ssl-key
parameters in the configuration file when you start the TiDB server. You can also specify the ssl-ca
parameter for client authentication (see Enable authentication).
All the files specified by the parameters are in PEM (Privacy Enhanced Mail) format. Currently, TiDB does not support the import of a password-protected private key, so it is required to provide a private key file without a password. If the certificate or private key is invalid, the TiDB server starts as usual, but the client cannot connect to the TiDB server through an encrypted connection.
The certificate or key is signed and generated using OpenSSL, or quickly generated using the mysql_ssl_rsa_setup
tool in MySQL:
mysql_ssl_rsa_setup --datadir=./certs
This command generates the following files in the certs
directory:
certs
├── ca-key.pem
├── ca.pem
├── client-cert.pem
├── client-key.pem
├── private_key.pem
├── public_key.pem
├── server-cert.pem
└── server-key.pem
The corresponding TiDB configuration file parameters are:
[security]
ssl-cert = "certs/server-cert.pem"
ssl-key = "certs/server-key.pem"
If the certificate parameters are correct, TiDB outputs secure connection is enabled
when started; otherwise, it outputs secure connection is NOT ENABLED
.
Reload certificate, key, and CA
To replace the certificate, the key or CA, first replace the corresponding files, then execute the ALTER INSTANCE RELOAD TLS
statement on the running TiDB instance to reload the certificate (ssl-cert
), the key (ssl-key
), and the CA (ssl-ca
) from the original configuration path. In this way, you do not need to restart the TiDB instance.
The newly loaded certificate, key, and CA take effect on the connection that is established after the statement is successfully executed. The connection established before the statement execution is not affected.
Configure the MySQL client to use encrypted connections
The client of MySQL 5.7 or later versions attempts to establish an encrypted connection by default. If the server does not support encrypted connections, it automatically returns to unencrypted connections. The client of MySQL earlier than version 5.7 uses the unencrypted connection by default.
You can change the connection behavior of the client using the following --ssl-mode
parameters:
--ssl-mode=REQUIRED
: The client requires an encrypted connection. The connection cannot be established if the server side does not support encrypted connections.- In the absence of the
--ssl-mode
parameter: The client attempts to use an encrypted connection, but the encrypted connection cannot be established if the server side does not support encrypted connections. Then the client uses an unencrypted connection. --ssl-mode=DISABLED
: The client uses an unencrypted connection.
For more information, see Client-Side Configuration for Encrypted Connections in MySQL.
Enable authentication
If the ssl-ca
parameter is not specified in the TiDB server or MySQL client, the client or the server does not perform authentication by default and cannot prevent man-in-the-middle attack. For example, the client might "securely" connect to a disguised client. You can configure the ssl-ca
parameter for authentication in the server and client. Generally, you only need to authenticate the server, but you can also authenticate the client to further enhance the security.
To authenticate the TiDB server from the MySQL client:
- Specify the
ssl-cert
andssl-key
parameters in the TiDB server. - Specify the
--ssl-ca
parameter in the MySQL client. - Specify the
--ssl-mode
toVERIFY_CA
at least in the MySQL client. - Make sure that the certificate (
ssl-cert
) configured in the TiDB server is signed by the CA specified by the client--ssl-ca
parameter; otherwise, the authentication fails.
- Specify the
To authenticate the MySQL client from the TiDB server:
- Specify the
ssl-cert
,ssl-key
, andssl-ca
parameters in the TiDB server. - Specify the
--ssl-cert
and--ssl-key
parameters in the client. - Make sure the server-configured certificate and the client-configured certificate are both signed by the
ssl-ca
specified by the server.
- Specify the
- To perform mutual authentication, meet both of the above requirements.
By default, the server-to-client authentication is optional. Even if the client does not present its certificate of identification during the TLS handshake, the TLS connection can be still established. You can also require the client to be authenticated by specifying require 509
when creating a user (create user
), granting permissions (grant
), or modifying an existing user (alter user
). The following is an example of creating a user:
create user 'u1'@'%' require x509;
If the login user has configured using the TiDB Certificate-Based Authentication for Login, the user is implicitly required to enable the encrypted connection to TiDB.
Check whether the current connection uses encryption
Use the SHOW STATUS LIKE "%Ssl%";
statement to get the details of the current connection, including whether encryption is used, the encryption protocol used by encrypted connections, the TLS version number and so on.
See the following example of the result in an encrypted connection. The results change according to different TLS versions or encryption protocols supported by the client.
mysql> SHOW STATUS LIKE "%Ssl%";
......
| Ssl_verify_mode | 5 |
| Ssl_version | TLSv1.2 |
| Ssl_cipher | ECDHE-RSA-AES128-GCM-SHA256 |
......
For the official MySQL client, you can also use the STATUS
or \s
statement to view the connection status:
mysql> \s
...
SSL: Cipher in use is ECDHE-RSA-AES128-GCM-SHA256
...
Supported TLS versions, key exchange protocols, and encryption algorithms
The TLS versions, key exchange protocols and encryption algorithms supported by TiDB are determined by the official Golang libraries.
Supported TLS versions
- TLS 1.0
- TLS 1.1
- TLS 1.2
- TLS 1.3
Supported key exchange protocols and encryption algorithms
- TLS_RSA_WITH_AES_128_CBC_SHA
- TLS_RSA_WITH_AES_256_CBC_SHA
- TLS_RSA_WITH_AES_128_CBC_SHA256
- TLS_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
- TLS_AES_128_GCM_SHA256
- TLS_AES_256_GCM_SHA384
- TLS_CHACHA20_POLY1305_SHA256