mod_http_oauth2: Implement stateless dynamic client registration Replaces previous explicit registration that required either the additional module mod_adhoc_oauth2_client or manually editing the database. That method was enough to have something to test with, but would not probably not scale easily. Dynamic client registration allows creating clients on the fly, which may be even easier in theory. In order to not allow basically unauthenticated writes to the database, we implement a stateless model here. per_host_key := HMAC(config -> oauth2_registration_key, hostname) client_id := JWT { client metadata } signed with per_host_key client_secret := HMAC(per_host_key, client_id) This should ensure everything we need to know is part of the client_id, allowing redirects etc to be validated, and the client_secret can be validated with only the client_id and the per_host_key. A nonce injected into the client_id JWT should ensure nobody can submit the same client metadata and retrieve the same client_secret

---
labels:
- Stage-Beta
summary: "XEP-0388: Extensible SASL Profile"
---

Implementation of [XEP-0388: Extensible SASL Profile]. **Note: At the time of
writing (Nov 2022) the version of the XEP implemented by this module is still
working its way through the XSF standards process. See [PR #1214](https://github.com/xsf/xeps/pull/1214)
for the current status.**

## Configuration

This module honours the same configuration options as Prosody's existing
[mod_saslauth](https://prosody.im/doc/modules/mod_saslauth).

## Developers

mod_sasl2 provides some events you can hook to affect aspects of the
authentication process:

- `advertise-sasl-features`
- `sasl2/c2s/success`
  - Priority 1000: Session marked as authenticated, success response created (`event.success`)
  - Priority -1000: Success response sent to client
  - Priority -1500: Updated <stream-features/> sent to client
- `sasl2/c2s/failure`
- `sasl2/c2s/error`