Configure SSL/TLS certificates

This page describes how to configure an instance to use SSL/TLS. You can also learn more about how Cloud SQL uses self-managed SSL/TLS certificates to securely connect to Cloud SQL instances.

Overview

Cloud SQL creates a server certificate (server-ca.pem) automatically when you create your instance. We recommend that you enforce all connections to use SSL/TLS.

SQL Server only performs certificate verification when the client request explicitly specifies that it requires an encrypted connection. In this case the server certificate must be installed on the client machine. Otherwise, clients are able to freely connect with no additional changes to their connection strings or certificates, even if you configure the instance with sslMode set to ENCRYPTED_ONLY.

For more information, see the Enable encrypted connections to the Database Engine section in the SQL Server documentation.

If you enforce SSL for an instance, then the instance requires a restart. A restart might also be required after you change SSL/TLS certificates. When a restart is required, Cloud SQL automatically restarts the instance for you. The restart of an instance can incur downtime.

Enforce SSL/TLS encryption

You can use the SSL mode setting to enforce SSL encryption in the following ways:

  • Allow both non-SSL/non-TLS and SSL/TLS connections. This is the default.

  • Only allow connections encrypted with SSL/TLS.

If you select Allow non-SSL/non-TLS and SSL/TLS connections for your Cloud SQL instance, SSL/TLS connections are accepted, as well as unencrypted and unsecure connections. If you do not require SSL/TLS for all connections, unencrypted connections are still allowed. For this reason, if you are accessing your instance using public IP, we strongly recommend that you enforce SSL for all connections.

You can connect either directly to instances by using SSL/TLS certificates, or you can connect by using the Cloud SQL Auth Proxy or Cloud SQL Connectors. If you connect by using Cloud SQL Auth Proxy or Cloud SQL Connectors, then the connections are automatically encrypted with SSL/TLS. With Cloud SQL Auth Proxy and Cloud SQL Connectors, client and server identities are also automatically verified regardless of the SSL mode setting.

Enforcing SSL ensures that all connections are encrypted.

To enable requiring SSL/TLS, do the following:

Console

  1. In the Google Cloud console, go to the Cloud SQL Instances page.

    Go to Cloud SQL Instances

  2. To open the Overview page of an instance, click the instance name.
  3. Click Connections from the SQL navigation menu.
  4. Select the Security tab.
  5. Select one of the following:
    • Allow unencrypted network traffic (not recommended)
    • Allow only SSL connections. This option only allows connections using SSL/TLS encryption.

gcloud

   gcloud sql instances patch INSTANCE_NAME \
   --ssl-mode=SSL_ENFORCEMENT_MODE

Replace SSL_ENFORCEMENT_MODE with one of the following options:

  • ALLOW_UNENCRYPTED_AND_ENCRYPTED allows non-SSL/non-TLS and SSL/TLS connections. This is the default value.
  • ENCRYPTED_ONLY only allows connections encrypted with SSL/TLS.

Terraform

To enforce SSL/TLS encryption, use a Terraform resource: 

resource "google_sql_database_instance" "sqlserver_instance" {
  name             = "sqlserver-instance"
  region           = "asia-northeast1"
  database_version = "SQLSERVER_2019_STANDARD"
  root_password    = "INSERT-PASSWORD-HERE"
  settings {
    tier = "db-custom-2-7680"
    ip_configuration {
      require_ssl = "true"
    }
  }
  # set `deletion_protection` to true, will ensure that one cannot accidentally delete this instance by
  # use of Terraform whereas `deletion_protection_enabled` flag protects this instance at the GCP level.
  deletion_protection = false
}

Apply the changes

To apply your Terraform configuration in a Google Cloud project, complete the steps in the following sections.

Prepare Cloud Shell

  1. Launch Cloud Shell.

  2. Set the default Google Cloud project where you want to apply your Terraform configurations.

    You only need to run this command once per project, and you can run it in any directory.

    export GOOGLE_CLOUD_PROJECT=PROJECT_ID

    Environment variables are overridden if you set explicit values in the Terraform configuration file.

Prepare the directory

Each Terraform configuration file must have its own directory (also called a root module).

  1. In Cloud Shell, create a directory and a new file within that directory. The filename must have the .tf extension—for example main.tf. In this tutorial, the file is referred to as main.tf. 
    mkdir DIRECTORY && cd DIRECTORY && touch main.tf

  2. If you are following a tutorial, you can copy the sample code in each section or step.

    Copy the sample code into the newly created main.tf.

    Optionally, copy the code from GitHub. This is recommended when the Terraform snippet is part of an end-to-end solution.

  3. Review and modify the sample parameters to apply to your environment.
  4. Save your changes.
  5. Initialize Terraform. You only need to do this once per directory. 
    terraform init

    Optionally, to use the latest Google provider version, include the -upgrade option: 

    terraform init -upgrade

Apply the changes

  1. Review the configuration and verify that the resources that Terraform is going to create or update match your expectations: 
    terraform plan

    Make corrections to the configuration as necessary.

  2. Apply the Terraform configuration by running the following command and entering yes at the prompt: 
    terraform apply

    Wait until Terraform displays the "Apply complete!" message.

  3. Open your Google Cloud project to view the results. In the Google Cloud console, navigate to your resources in the UI to make sure that Terraform has created or updated them.

Delete the changes

To delete your changes, do the following:

  1. To disable deletion protection, in your Terraform configuration file set the deletion_protection argument to false. 
    deletion_protection =  "false"
  2. Apply the updated Terraform configuration by running the following command and entering yes at the prompt: 
    terraform apply

  1. Remove resources previously applied with your Terraform configuration by running the following command and entering yes at the prompt:

    terraform destroy

REST v1

  1. Before using any of the request data, make the following replacements:

    • PROJECT_ID: The project ID
    • SSL_ENFORCEMENT_MODE: Use one of the following options:
      • ALLOW_UNENCRYPTED_AND_ENCRYPTED: allows non-SSL/non-TLS and SSL/TLS connections.
      • ENCRYPTED_ONLY: only allows connections encrypted with SSL/TLS.
    • INSTANCE_ID: The instance ID

    HTTP method and URL: 

    PATCH https://sqladmin.googleapis.com/v1/projects/PROJECT_ID/instances/INSTANCE_ID

    Request JSON body: 

    
{
  "settings": {
    "ipConfiguration": {"sslMode": "SSL_ENFORCEMENT_MODE"}
  }
}

    To send your request, expand one of these options:

    You should receive a JSON response similar to the following:

REST v1beta4

  1. Before using any of the request data, make the following replacements:

    • PROJECT_ID: The project ID
    • SSL_ENFORCEMENT_MODE: Use one of the following options:
      • ALLOW_UNENCRYPTED_AND_ENCRYPTED: allows non-SSL/non-TLS and SSL/TLS connections.
      • ENCRYPTED_ONLY: only allows connections encrypted with SSL/TLS.
    • INSTANCE_ID: The instance ID

    HTTP method and URL: 

    PATCH https://sqladmin.googleapis.com/sql/v1beta4/projects/PROJECT_ID/instances/INSTANCE_ID

    Request JSON body: 

    {
  "settings": {
    "ipConfiguration": {"sslMode": "SSL_ENFORCEMENT_MODE"}
  }
}

    To send your request, expand one of these options:

    You should receive a JSON response similar to the following:

Server certificates

Cloud SQL creates a server certificate automatically when you create your instance. As long as the server certificate is valid, you don't need to actively manage your server certificate. However, the certificate has an expiration date of 10 years; after that date, it is no longer valid, and clients are not able to establish a secure connection to your instance using that certificate. You're periodically notified that the server certificate is nearing expiration. The notifications are sent the following number of days before the expiration date: 90, 30, 10, 2, and 1.

You can get information about your server certificate, such as when it was created and when it expires, or manually create a new one.

Console

  1. In the Google Cloud console, go to the Cloud SQL Instances page.

    Go to Cloud SQL Instances

  2. To open the Overview page of an instance, click the instance name.
  3. Click Connections from the SQL navigation menu.
  4. Select the Security tab.
  5. Go to the Manage server certificates section.

    You can see the expiration date of your server certificate in the table.

gcloud

  1. Get information about the service certificate: 
    gcloud beta sql ssl server-ca-certs list \
--instance=INSTANCE_NAME
  2. Create a server certificate: 
    gcloud beta sql ssl server-ca-certs create \
--instance=INSTANCE_NAME
  3. Download the certificate information to a local PEM file: 
    gcloud beta sql ssl server-ca-certs list \
--format="value(cert)" \
--instance=INSTANCE_NAME > \
FILE_PATH/FILE_NAME.pem
  4. Update all of your clients to use the new information by copying the downloaded file to your client host machines, replacing the existing server-ca.pem files.

Terraform

To provide server certificate information as an output, use a Terraform data source:

  1. Add the following to your Terraform configuration file: 
       data "google_sql_ca_certs" "ca_certs" {
     instance = google_sql_database_instance.default.name
   }

   locals {
     furthest_expiration_time = reverse(sort([for k, v in data.google_sql_ca_certs.ca_certs.certs : v.expiration_time]))[0]
     latest_ca_cert           = [for v in data.google_sql_ca_certs.ca_certs.certs : v.cert if v.expiration_time == local.furthest_expiration_time]
   }

   output "db_latest_ca_cert" {
     description = "Latest CA certificate used by the primary database server"
     value       = local.latest_ca_cert
     sensitive   = true
   }
  2. To create the server-ca.pem file, run the following command: 
       terraform output db_latest_ca_cert > server-ca.pem

Use encrypted connections

Learn more about how SQL Server uses encrypted connections.

What's next