ApsaraDB RDS:Configure a client CA certificate

Step 1: Create a client certificate

In this example, CentOS is used. If you use a Windows operating system, you can configure the openssl command by using the same openssl configuration that you use in CentOS.

1. Create a self-signed certificate and a private key for the self-signed certificate. The self-signed certificate is saved in a file named ca1.crt. The private key is saved in a file named ca1.key.

   openssl req -new -x509 -days 3650 -nodes -out ca1.crt -keyout ca1.key -subj "/CN=root-ca1"

2. Create a certificate signing request (CSR) and a private key for the client certificate. The CSR is used to request a client certificate and is saved in a file named client.csr. The private key is saved in a file named client.key.

   openssl req -new -nodes -text -out client.csr -keyout client.key -subj "/CN=<Username that is used for logons from the client>

   "

   Note

   In the preceding command, the CN parameter follows the -subj parameter. You must set the CN parameter to the username of the account that is used by the client to connect to the RDS instance.

3. Create a client certificate. The client certificate is saved in a file named client.crt.

   openssl x509 -req -in client.csr -text -days 365  -CA ca1.crt -CAkey ca1.key -CAcreateserial  -out client.crt

# ls
ca1.crt  ca1.key  ca1.srl  client.crt  client.csr  client.key

Step 2: Configure a client CA certificate

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the left-side navigation pane of the page that appears, click Data Security. On the page that appears, click the SSL tab.

3. Click Enable Client CA Certificate.

   

4. In the dialog box that appears, copy the content of the ca1.crt file to the Public Key field. Then, click OK. For more information about how to obtain the ca1.crt file, see Step 1: Create a client certificate.

   

Step 3: Connect to the RDS instance from the client

You can connect to the RDS instance from the client over SSL connections. For more information, see Connect to an ApsaraDB RDS for PostgreSQL instance over SSL connections.

Step 4: (Optional) Configure a CRL file

If you no longer need the client certificate, you can revoke the client certificate. After the client certificate is revoked, the RDS instance denies access requests from the client.

1. Prepare the configuration file

   touch /etc/pki/CA/index.txt
   echo 1000 > /etc/pki/CA/crlnumber

   Note

   If you use a Windows operating system, you must perform the following operations:

   1. Create a CA folder in the Installation directory of OpenSSL\bin directory.

   2. Create a file named index.txt in the CA folder.

   3. Run the following command by using the PostgreSQL CLI:

      echo 1000 > <Installation directory of OpenSSL>\bin\CA\crlnumber

   4. Modify the openssl.cnf file in C:\Program Files\Common Files\SSL\.

      # Find the [ CA_default ] configuration item.
      
      dir = "<Installation directory of OpenSSL>\\bin\\CA"

2. Revoke the client certificate, which is contained in the client.crt file.

   openssl ca -revoke client.crt -cert ca1.crt -keyfile ca1.key

   Note

   The preceding command requires the self-signed certificate and the private key of the self-signed certificate. The self-signed certificate is contained in the ca1.crt file, and the private key of the self-signed certificate is contained in the ca1.key file. For more information, see the Step 1: Create a client certificate.

3. Create a CRL. The CRL is saved in a file named client.crl.

   openssl ca -gencrl -out client.crl -cert ca.crt -keyfile ca.key

4. In the left-side navigation pane of the page that appears, click Data Security. On the page that appears, click the SSL tab.

5. Click Enable Certificate Revocation File.

   

6. In the dialog box that appears, copy the content of the client.crl file to the Revocation File field.

   

Step 5: (Optional) Update the client certificate