SSL/TLS certificates

Introduction

It is often desired to use SSL connections (also known as TLS connections) for communications to avoid "man in the middle" attacks. Godot has a connection wrapper, StreamPeerTLS, which can take a regular connection and add security around it. The HTTPClient and HTTPRequest classes also support HTTPS using this same wrapper.

Godot includes the SSL certificate bundle from Mozilla, but you can provide your own with a CRT file in the Project Settings:

Setting the TLS certificate bundle override project setting

When set, this file overrides the Mozilla certificate bundle Godot uses by default. This file should contain any number of public certificates in PEM format.

Remember to add *.crt as the non-resource export filter to your export preset, so that the exporter recognizes this when exporting your project:

Adding *.crt to non-resource export filter in the export preset

There are two ways to obtain certificates:

Acquire a certificate from a certificate authority

The main approach to getting a certificate is to use a certificate authority (CA) such as Let's Encrypt. This is a more cumbersome process than a self-signed certificate, but it's more "official" and ensures your identity is clearly represented. The resulting certificate is also trusted by applications such as web browsers, unlike a self-signed certificate which requires additional configuration on the client side before it's considered trusted.

These certificates do not require any configuration on the client to work, since Godot already bundles the Mozilla certificate bundle in the editor and exported projects.

Generate a self-signed certificate

For most use cases, it's recommended to go through certificate authority as the process is free with certificate authorities such as Let's Encrypt. However, if using a certificate authority is not an option, then you can generate a self-signed certificate and tell the client to consider your self-signed certificate as trusted.

To create a self-signed certificate, generate a private and public key pair and add the public key (in PEM format) to the CRT file specified in the Project Settings.

WARNING

The private key should only go to your server. The client must not have access to it: otherwise, the security of the certificate will be compromised.

OpenSSL has some documentation about this. For local development purposes only, mkcert can be used as an alternative.