view mod_s2s_auth_dane/README.md @ 6319:04c3273cb81f

mod_auth_cyrus: Add empty 'profile' table to SASL handler objects This is for compatibility with Prosody's built-in util.sasl objects. A SASL profile table usually includes methods supported by the backend, which can be used by SASL mechanism handlers to perform operations (such as testing the password). It also optionally contains a 'cb' field with channel binding method handlers. The Cyrus backend doesn't support channel binding, and doesn't have the same concept of auth backend methods (it handles all that internally, and Prosody has no insight or control over it). Thus, we create an empty profile which informs Prosody that the SASL handler does not support any of the auth or channel binding methods. Some features will not work, but they didn't work anyway. This just makes it explicit. This fixes a traceback in mod_sasl2_fast, which expected SASL handlers to always contain a 'profile' field.
author Matthew Wild <mwild1@gmail.com>
date Thu, 04 Sep 2025 10:14:46 +0100
parents f315edc39f3d
children
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---
labels:
- Stage-Obsolete
- Type-S2SAuth
summary: S2S authentication using DANE
...

::: {.alert .alert-warning}
This module no longer works with recent versions of Prosody.

However, Prosody as of [13.0.0](//prosody.im/doc/release/13.0.0) ships with native support for [DANE](//prosody.im/doc/dnssec).
:::

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

This module implements DANE as described in [Using DNS Security
Extensions (DNSSEC) and DNS-based Authentication of Named Entities
(DANE) as a Prooftype for XMPP Domain Name
Associations](http://tools.ietf.org/html/draft-miller-xmpp-dnssec-prooftype).

Dependencies
============

This module requires a DNSSEC aware DNS resolver. Prosodys internal DNS
module does not support DNSSEC. Therefore, to use this module, a
replacement is needed, such as [this
one](https://www.zash.se/luaunbound.html).

LuaSec 0.5 or later is also required.

Configuration
=============

After [installing the module][doc:installing\_modules], just add it to
`modules_enabled`;

    modules_enabled = {
     ...
     "s2s_auth_dane";
    }

DANE Uses
---------

By default, only DANE uses are enabled.

    dane_uses = { "DANE-EE", "DANE-TA" }

  Use flag    Description
  ----------- -------------------------------------------------------------------------------------------------------
  `DANE-EE`   Most simple use, usually a fingerprint of the full certificate or public key used the service
  `DANE-TA`   Fingerprint of a certificate or public key that has been used to issue the service certificate
  `PKIX-EE`   Like `DANE-EE` but the certificate must also pass normal PKIX trust checks (ie standard certificates)
  `PKIX-TA`   Like `DANE-TA` but must also pass normal PKIX trust checks (ie standard certificates)

DNS Setup
=========

In order for other services to verify your site using using this plugin,
you need to publish TLSA records (and they need to have this plugin).
Here's an example using `DANE-EE Cert SHA2-256` for a host named
`xmpp.example.com` serving the domain `example.com`.

    $ORIGIN example.com.
    ; Your standard SRV record
    _xmpp-server._tcp.example.com IN SRV 0 0 5269 xmpp.example.com.
    ; IPv4 and IPv6 addresses
    xmpp.example.com. IN A 192.0.2.68
    xmpp.example.com. IN AAAA 2001:0db8:0000:0000:4441:4e45:544c:5341

    ; The DANE TLSA records.
    _5269._tcp.xmpp.example.com. 300 IN TLSA 3 0 1 E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855

    ; If your zone file tooling does not support TLSA records, you can try the raw binary format:
    _5269._tcp.xmpp.example.com. 300 IN TYPE52 \# 35 030001E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855

[List of DNSSEC and DANE
tools](http://www.internetsociety.org/deploy360/dnssec/tools/)

Further reading
===============

-   [DANE Operational Guidance][rfc7671]

# Compatibility

  version   status
  --------- ------------
  trunk     broken[^1]
  0.12      broken
  0.11      works
  0.10      works
  0.9       works

**Broken** since [trunk revision 756b8821007a](https://hg.prosody.im/trunk/rev/756b8821007a).

# Known issues

-   A race condition between the DANE lookup and completion of the TLS
    handshake may cause a crash. This does not happen in **trunk**
    thanks to better async support.

[^1]: since [756b8821007a](https://hg.prosody.im/trunk/rev/756b8821007a)