Online Software Licensing System

Install

Requires system with systemd and Go (at least 1.18).

sudo make install

make install builds, and sets up /opt/licensing-server directory, where the built binary will be copied to. Also generates keys file and sets up LICENSING_SERVER_KEY variable in .env. keys file includes licensing server's public and private keys, used by licensing protocol to function.
Client's software should have public part (aka id) hard-coded into the binary.

For system to work, couple environment config variables are required, this includes:

• DB_DSN (See PostgreSQL)
• LICENSING_SERVER_KEY (Autogenerated by make install)

PostgreSQL

PostgreSQL is required for system to function. Database credentials should be entered in /opt/licensing-server/.env in the following format:

DB_DSN=postgres://licensingUname:securePasswd@localhost:5432/licensingDB?sslmode=disable

Starting

Using systemd service:

sudo systemctl enable --now licensing.server.service

Env config

System has a lot of options to configure to fit your needs. Default location of the config is located in /opt/licensing-server/.env.

Supported environment config variables include:

Variable	Meaning
DB_DSN	Used for connecting to a database (should start with postgres://).
DISABLE_GUI	Disables integrated webpage (default: false).
HTTP_LISTEN	Specifies TCP address for server to listen on (default: :http/:https depending on TLS).
HTTP_READ_TIMEOUT	Maximum duration for reading entire request (default: 30s).
HTTP_WRITE_TIMEOUT	Maximum duration before timing out writes of the response (default: 30s).
HTTP_SHUTDOWN_TIMEOUT	Maximum duration before server shutdown is forced (default `30s).
HTTP_GZIP	Use gzip compression for requests (default false).
HTTP_CORS_RESOURCE_API_ENABLED	Use CORS for resource API (issuers, products, licenses) (default: false).
HTTP_CORS_LICENSING_API_ENABLED	Use CORS for licensing API (creating, refreshing license sessions) (default: false).
HTTP_CORS_ALLOWED_ORIGINS	Allowed origins for CORS.
HTTP_TLS_CERT_FILE	TLS certificate file.
HTTP_TLS_KEY_FILE	TLS private key file.
INTERNAL_SOCKET	Socket path for internal CLI (default: /run/licensing-server.sock).
LICENSING_SERVER_KEY	Licensing server's private key, base64 encoded.
LICENSING_MAX_TIME_DRIFT	Max allowed time drift between server and client (default: 6h).
LICENSING_CLEANUP_INTERVAL	Inactive/expired/overused license sessions cleanup interval (default: 20m).
LICENSING_REFRESH_MIN	License session minimum refresh duration (default: 5m).
LICENSING_REFRESH_MAX	License session maximum refresh duration (default: 2h).
LICENSING_REFRESH_JITTER	License session refresh duration variance, 0.0-1.0 (default: 0.1).
LICENSING_LIMITER_SESSION_EVERY	New license sessions creation rate limiter to allow every x interval (default: 10m).
LICENSING_LIMITER_BURST_TOTAL	New license sessions creation rate limiter max burst worth in session time (default: 8h).
LICENSING_LIMITER_CACHE_EXPIRATION	New license sessions creation rate limiter cache expiration (default: 24h).
LICENSING_LIMITER_CACHE_CLEANUP_INTERVAL	New license sessions creation rate limiter cache cleanup interval (default: 1h).
MIN_PASSWD_ENTROPY	Minimum required entropy for issuer passwords, see zxcvbn (default: 30).

See cmd/server/config.go.