Establishing Secure TCP/IP Connections in SSL Mode

Configuring SSL Connection

Prerequisites

• After you have modified the security parameters and the modifications take effect, the cluster may be restarted, which makes the cluster unavailable temporarily.
• To modify the cluster's security configuration, ensure that the following conditions are met:
  • The cluster status is Available or Unbalanced.
  • The Task Information cannot be set to Creating snapshot, Scaling out, Configuring, or Restarting.

Procedure

1. Log in to the GaussDB(DWS) management console.
2. In the navigation pane on the left, choose Clusters > Dedicated Clusters.
3. In the cluster list, click the name of a cluster. On the page that is displayed, click Security Settings.

   By default, Configuration Status is Synchronized, which indicates that the latest database result is displayed.

4. In the SSL Connection area, enable Require SSL Connection (recommended).

   indicates the function is enabled. The require_ssl is set to 1, indicating that the server forcibly requires the SSL connection.

   indicates the function is disabled (default value). The require_ssl parameter is set to 0, indicating that the server does not require SSL connections. For details about how to configure the require_ssl parameter, see require_ssl (Server).

   

   • If the gsql client or ODBC driver provided by GaussDB(DWS) is used, GaussDB(DWS) supports the TLSv1.2 SSL protocol.
   • If the JDBC driver provided by GaussDB(DWS) is used, GaussDB(DWS) supports SSL protocols, such as SSLv3, TLSv1, TLSv1.1, and TLSv1.2. The SSL protocol used between the client and the database depends on the Java Development Kit (JDK) version used by the client. Generally, JDK supports multiple SSL protocols.

5. Click Apply.

   The system automatically saves the SSL connection settings. On the Security Settings page, Configuration Status is Applying. After Configuration Status changes to Synchronized, the settings have been saved and taken effect.

Configuring Digital Certificate Parameters Related to SSL Authentication on the gsql Client

After a data warehouse cluster is deployed, the SSL authentication mode is enabled by default. The server certificate, private key, and root certificate have been configured by default. You need to configure the client parameters.

1. Log in to the GaussDB(DWS) management console. In the navigation pane, choose Client Connections.
2. In the Driver area, click download an SSL certificate.
3. Use a file transfer tool (such as WinSCP) to upload the SSL certificate to the host where the client is installed.

   For example, save the downloaded certificate dws_ssl_cert.zip to the /home/dbadmin/dws_ssl/ directory.

4. Use an SSH remote connection tool (such as PuTTY) to log in to the host where the gsql client is installed and run the following commands to go to the directory where the SSL certificate is stored and decompress the SSL certificate:

   cd /home/dbadmin/dws_ssl/
   unzip dws_ssl_cert.zip

5. Run the export command and configure digital certificate parameters related to SSL authentication on the host where the gsql client is installed.

   There are two SSL authentication modes: bidirectional authentication and unidirectional authentication. The client environment variables to be configured vary according to the authentication mode. For details, see SSL Authentication Modes and Client Parameters.

   The following parameters must be configured for bidirectional authentication:

   export PGSSLCERT="/home/dbadmin/dws_ssl/sslcert/client.crt"
   export PGSSLKEY="/home/dbadmin/dws_ssl/sslcert/client.key"
   export PGSSLMODE="verify-ca"
   export PGSSLROOTCERT="/home/dbadmin/dws_ssl/sslcert/cacert.pem"

   The following parameters must be configured for unidirectional authentication:

   export PGSSLMODE="verify-ca"
   export PGSSLROOTCERT="/home/dbadmin/dws_ssl/sslcert/cacert.pem"

   

   • You are advised to use bidirectional authentication for security purposes.
   • The environment variables configured for a client must contain the absolute file paths.

6. Change the client private key permissions.

   The permissions on the client's root certificate, private key, certificate, and encrypted private key file must be 600. If the permissions do not meet the requirement, the client cannot connect to the cluster in SSL mode.

   chmod 600 client.key
   chmod 600 client.crt
   chmod 600 client.key.cipher
   chmod 600 client.key.rand
   chmod 600 cacert.pem

SSL Authentication Modes and Client Parameters

There are two SSL authentication modes: bidirectional authentication and unidirectional authentication. Table Table 1 shows the differences between these two modes. You are advised to use bidirectional authentication for security purposes.

Configure environment variables related to SSL authentication on the client. For details, see Table 2.

The path of environment variables is set to /home/dbadmin/dws_ssl/ as an example. Replace it with the actual path.

export PGSSLCERT='/home/dbadmin/dws_ssl/sslcert/client.crt'

export PGSSLKEY='/home/dbadmin/dws_ssl/sslcert/client.key'

export PGSSLROOTCERT='/home/dbadmin/dws_ssl/sslcert/certca.pem'

export PGSSLCRL='/home/dbadmin/dws_ssl/sslcert/sslcrl-file.crl'

Combinations of SSL Connection Parameters on the Client and Server

Whether the client uses the SSL encryption connection mode and whether to verify the server certificate depend on client parameter sslmode and server (cluster) parameters ssl and require_ssl. The parameters are as follows:

• ssl (Server)
  The ssl parameter indicates whether to enable the SSL function. on indicates that the function is enabled, and off indicates that the function is disabled.

  • The default value is on and you cannot set this parameter on the GaussDB(DWS) management console.
• require_ssl (Server)
  The require_ssl parameter specifies whether the server forcibly requires SSL connection. This parameter is valid only when ssl is set to on. on indicates that the server forcibly requires SSL connection. off indicates that the server does not require SSL connection.

  • The default value is off. You can set the require_ssl parameter in the Require SSL Connection area of the cluster's Security Settings page on the GaussDB(DWS) management console.
• sslmode (Client)
  You can set this parameter in the SQL client tool.

  • In the gsql command line client, this parameter is the PGSSLMODE parameter.
  • On the Data Studio client, this parameter is the SSL Mode parameter.

The combinations of client parameter sslmode and server parameters ssl and require_ssl are as follows.