File

mod_s2s_keysize_policy/README.markdown @ 5193:2bb29ece216b

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
author Kim Alvefur <zash@zash.se>
date Fri, 03 Mar 2023 21:14:19 +0100
parent 1895:101078d9cc27
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---
summary: Distrust servers with too small keys
...

Introduction
============

This module sets the security status of s2s connections to invalid if
their key is too small and their certificate was issued after 2014, per
CA/B Forum guidelines.

Details
=======

Certificate Authorities were no longer allowed to issue certificates
with public keys smaller than 2048 bits (for RSA) after December 31
2013. This module was written to enforce this, as there were some CAs
that were slow to comply. As of 2015, it might not be very relevant
anymore, but still useful for anyone who wants to increase their
security levels.

When a server is determined to have a "too small" key, this module sets
its chain and identity status to "invalid", so Prosody will treat it as
a self-signed certificate istead.

"Too small"
-----------

The definition of "too small" is based on the key type and is taken from
[RFC 4492].

  Type     bits
  ------ ------
  RSA      2048
  DSA      2048
  DH       2048
  EC        233

Compatibility
=============

Works with Prosody 0.9 and later. Requires LuaSec with [support for
inspecting public keys](https://github.com/brunoos/luasec/pull/19).