#authentication

An interactive Python script that proves an identity provider is ready for a client: it rehearses a full PKCE sign-in and sign-out like an application, then checks the tokens it receives against the provider's keys the way an application must.

Opening a broker to browsers and devices on the internet is less about encryption than identity. Each entrance now accepts one kind of credential, every token is bound to its own name and addressed to this broker, and TLS ends in nginx.

Every new project needs a gateway, sign-in, and a first administrator before its backend exists. One generator command now builds that stack, working on first boot, by handling the values that fail silently when set by hand and a rerun that would keep the old database.

SMTP and IMAP credentials fail late and far from their cause: a reset email that never arrives. A small check proves both directions first, with a tokenised test message, a read-only inbox check, and broken config kept distinct from a broken server.

A laptop and a borrowed Colab GPU talked through a public MQTT broker that anyone could read. Giving that channel an identity took an afternoon on the broker and eight obstacles in the clients — mostly safeguards that were right for the old setup and wrong for the new one.

A failed login in a half-built service is either a misconfigured identity provider or wrong code. I rule out the first by rehearsing a full login with my own tool before writing any app, and found compliant providers still disagree on tokens and claims.