view mod_s2s_keysize_policy/README.markdown @ 5787:e79f9dec35c0

mod_c2s_conn_throttle: Reduce log level from error->info Our general policy is that "error" should never be triggerable by remote entities, and that it is always about something that requires admin intervention. This satisfies neither condition. The "warn" level can be used for unexpected events/behaviour triggered by remote entities, and this could qualify. However I don't think failed auth attempts are unexpected enough. I selected "info" because it is what is also used for other notable session lifecycle events.
author Matthew Wild <mwild1@gmail.com>
date Thu, 07 Dec 2023 15:46:50 +0000
parents 101078d9cc27
children
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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).