HSTS (HTTP Strict Transport Security) is a web security policy mechanism that helps protect websites against certain types of attacks, such as man-in-the-middle attacks. It ensures that browsers only interact with the site using secure HTTPS connections.
When a website uses HSTS, it sends an HTTP header (Strict-Transport-Security) to the browser, instructing it to always use HTTPS for all subsequent requests to the site. This prevents users from accidentally accessing the site over an insecure HTTP connection and protects against protocol downgrade attacks and cookie hijacking.
Example:
To enable HSTS on a web server, you need to configure it to send the Strict-Transport-Security header. Here is an example configuration for an Nginx server:
server {
listen 443 ssl;
server_name example.com;
ssl_certificate /path/to/cert.pem;
ssl_certificate_key /path/to/key.pem;
# Enable HSTS
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
location / {
# Your configuration here
}
}