SSL/TLS Configuration for PostgreSQL

1. Introduction

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are protocols that encrypt data transmitted over networks. Configuring SSL/TLS for PostgreSQL enhances data security by ensuring that data in transit is encrypted and protected from eavesdropping.

2. Key Concepts

2.1 SSL vs TLS

SSL is the predecessor of TLS. While SSL is no longer considered secure, the term SSL is still commonly used to refer to both protocols.

2.2 Certificates

SSL/TLS requires certificates for authentication. Typically, a server certificate is issued by a certificate authority (CA), while a self-signed certificate can also be used for testing purposes.

3. Configuration Steps

3.1 Generate SSL Certificates

To enable SSL/TLS, you need valid certificates. You can generate self-signed certificates using the following commands:

openssl req -new -newkey rsa:2048 -days 365 -nodes -x509 -keyout server.key -out server.crt

This command generates a private key (server.key) and a certificate (server.crt).

3.2 Modify PostgreSQL Configuration

Edit the PostgreSQL configuration file (postgresql.conf) to enable SSL:

ssl = on
ssl_cert_file = 'path/to/server.crt'
ssl_key_file = 'path/to/server.key'

3.3 Restart PostgreSQL

After editing the configuration, restart the PostgreSQL service:

sudo systemctl restart postgresql

4. Best Practices

Important: Always use certificates issued by a trusted Certificate Authority (CA) in production.

Regularly update your certificates.
Use strong encryption protocols (TLS 1.2 or higher).
Restrict access to the private key file.
Enable SSL for all client connections.

5. FAQ

What happens if I don't configure SSL?

Without SSL, data transmitted between clients and the database server is sent in plaintext, making it vulnerable to interception.

Can I use self-signed certificates in production?

While self-signed certificates can be used in production, they are not recommended due to the lack of trust from clients. Instead, use certificates from a trusted CA.

How can I test my SSL configuration?

You can test your SSL configuration using the psql command with the sslmode parameter:

psql "host=your_server dbname=your_db user=your_user sslmode=require"