## LAYLO Code - Secure, resilient, privacy-friendly code hosting

This document gives an overview to the applied security standards that are in use on `code.laylo.cloud`.

### Goals

This Gitea instance is configured following best practices, in order to thwart low to medium level attacks. The threat model does not include protection against high-level adversaries (eg, nation states).

### Global

- The OS and software is updated every week (Thursdays, 22:00 - 23:59 CEST).
- The storage on the server is fully encrypted, both in OpenStack and the VM itself (the latter one using `AES-XTS-256`, see `misc/softraid.pdf` for the specification).
- The server _solely_ runs the Gitea stack (with Nginx and PostgreSQL), thus preventing additional attack surface.

### Web front-end

- Any plain-text (HTTP) traffic is redirected to the TLS secure counterpart (HTTPS).
- TLS (or more specifically: TLSv1.2 and TLSv1.3) is used for transit encryption - with HSTS and the following ciphers: 

	```
	ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-CHACHA20-POLY1305:AES-256-GCM-SHA384:EECDH+AESGCM:EDH+AESGCM
- OCSP stapling and OCSP must-stable are enabled.
- TLS session tickets are disabled (at least until Nginx fixes this properly).

### Networking

- The server itself is strictly firewalled (using `pf(8)`), both egress and ingress - on a daemon/service level.
- Internal service communication is encrypted (eg: Gitea is configured to connect to the local PostgreSQL server using TLS).

### Etc

- Official commits (eg, in the `laylo/docs` repository) are GPG signed, and MFA is enforced for accounts with write access.
- Backups are made every 24 hours, using a 'pull mechanism'. This server does **NOT** have access to the backup repository.
- SSH is hardened (PKI authentication, MFA via hardware tokens).
- The SSH fingerprint is: `SHA256:Uo+OE0V8yAMWTT0jyJrROJcJ5S9TmCnp3evQQ7xL538`.
- SSH ciphers are hardened, these are in use:

	```
	Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes256-ctr
	KexAlgorithms sntrup761x25519-sha512@openssh.com,curve25519-sha256@libssh.org,diffie-hellman-group18-sha512,diffie-hellman-group16-sha512
	MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com
	HostKeyAlgorithms ssh-ed25519,ssh-ed25519-cert-v01@openssh.com,rsa-sha2-256,rsa-sha2-512,rsa-sha2-256-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com
- The GPG public keys can be found in `signing-keys/`