Software / code / prosody
File
plugins/muc/members_only.lib.lua @ 13801:a5d5fefb8b68 13.0
mod_tls: Enable Prosody's certificate checking for incoming s2s connections (fixes #1916) (thanks Damian, Zash)
Various options in Prosody allow control over the behaviour of the certificate
verification process For example, some deployments choose to allow falling
back to traditional "dialback" authentication (XEP-0220), while others verify
via DANE, hard-coded fingerprints, or other custom plugins.
Implementing this flexibility requires us to override OpenSSL's default
certificate verification, to allow Prosody to verify the certificate itself,
apply custom policies and make decisions based on the outcome.
To enable our custom logic, we have to suppress OpenSSL's default behaviour of
aborting the connection with a TLS alert message. With LuaSec, this can be
achieved by using the verifyext "lsec_continue" flag.
We also need to use the lsec_ignore_purpose flag, because XMPP s2s uses server
certificates as "client" certificates (for mutual TLS verification in outgoing
s2s connections).
Commit 99d2100d2918 moved these settings out of the defaults and into mod_s2s,
because we only really need these changes for s2s, and they should be opt-in,
rather than automatically applied to all TLS services we offer.
That commit was incomplete, because it only added the flags for incoming
direct TLS connections. StartTLS connections are handled by mod_tls, which was
not applying the lsec_* flags. It previously worked because they were already
in the defaults.
This resulted in incoming s2s connections with "invalid" certificates being
aborted early by OpenSSL, even if settings such as `s2s_secure_auth = false`
or DANE were present in the config.
Outgoing s2s connections inherit verify "none" from the defaults, which means
OpenSSL will receive the cert but will not terminate the connection when it is
deemed invalid. This means we don't need lsec_continue there, and we also
don't need lsec_ignore_purpose (because the remote peer is a "server").
Wondering why we can't just use verify "none" for incoming s2s? It's because
in that mode, OpenSSL won't request a certificate from the peer for incoming
connections. Setting verify "peer" is how you ask OpenSSL to request a
certificate from the client, but also what triggers its built-in verification.
| author | Matthew Wild <mwild1@gmail.com> |
|---|---|
| date | Tue, 01 Apr 2025 17:26:56 +0100 |
| parent | 12977:74b9e05af71e |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- Copyright (C) 2014 Daurnimator -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local st = require "prosody.util.stanza"; local muc_util = module:require "muc/util"; local valid_affiliations = muc_util.valid_affiliations; local function get_members_only(room) return room._data.members_only; end local function set_members_only(room, members_only) members_only = members_only and true or nil; if room._data.members_only == members_only then return false; end room._data.members_only = members_only; if members_only then --[[ If as a result of a change in the room configuration the room type is changed to members-only but there are non-members in the room, the service MUST remove any non-members from the room and include a status code of 322 in the presence unavailable stanzas sent to those users as well as any remaining occupants. ]] local occupants_changed = {}; for _, occupant in room:each_occupant() do local affiliation = room:get_affiliation(occupant.bare_jid); if valid_affiliations[affiliation or "none"] <= valid_affiliations.none then occupant.role = nil; room:save_occupant(occupant); occupants_changed[occupant] = true; end end local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user"}) :tag("status", {code="322"}):up(); for occupant in pairs(occupants_changed) do room:publicise_occupant_status(occupant, x); module:fire_event("muc-occupant-left", {room = room; nick = occupant.nick; occupant = occupant;}); end end return true; end local function get_allow_member_invites(room) return room._data.allow_member_invites; end -- Allows members to invite new members into a members-only room, -- effectively creating an invite-only room local function set_allow_member_invites(room, allow_member_invites) allow_member_invites = allow_member_invites and true or nil; if room._data.allow_member_invites == allow_member_invites then return false; end room._data.allow_member_invites = allow_member_invites; return true; end module:hook("muc-disco#info", function(event) local members_only_room = not not get_members_only(event.room); local members_can_invite = not not get_allow_member_invites(event.room); event.reply:tag("feature", {var = members_only_room and "muc_membersonly" or "muc_open"}):up(); table.insert(event.form, { name = "{http://prosody.im/protocol/muc}roomconfig_allowmemberinvites"; label = "Allow members to invite new members"; type = "boolean"; value = members_can_invite; }); table.insert(event.form, { name = "muc#roomconfig_allowinvites"; label = "Allow users to invite other users"; type = "boolean"; value = not members_only_room or members_can_invite; }); end); module:hook("muc-config-form", function(event) table.insert(event.form, { name = "muc#roomconfig_membersonly"; type = "boolean"; label = "Only allow members to join"; desc = "Enable this to only allow access for room owners, admins and members"; value = get_members_only(event.room); }); table.insert(event.form, { name = "{http://prosody.im/protocol/muc}roomconfig_allowmemberinvites"; type = "boolean"; label = "Allow members to invite new members"; value = get_allow_member_invites(event.room); }); end, 90-3); module:hook("muc-config-submitted/muc#roomconfig_membersonly", function(event) if set_members_only(event.room, event.value) then event.status_codes["104"] = true; end end); module:hook("muc-config-submitted/{http://prosody.im/protocol/muc}roomconfig_allowmemberinvites", function(event) if set_allow_member_invites(event.room, event.value) then event.status_codes["104"] = true; end end); -- No affiliation => role of "none" module:hook("muc-get-default-role", function(event) if not event.affiliation and get_members_only(event.room) then return false; end end, 2); -- registration required for entering members-only room module:hook("muc-occupant-pre-join", function(event) local room = event.room; if get_members_only(room) then local stanza = event.stanza; local affiliation = room:get_affiliation(stanza.attr.from); if valid_affiliations[affiliation or "none"] <= valid_affiliations.none then local reply = st.error_reply(stanza, "auth", "registration-required", nil, room.jid):up(); event.origin.send(reply); return true; end end end, -5); -- Invitation privileges in members-only rooms SHOULD be restricted to room admins; -- if a member without privileges to edit the member list attempts to invite another user -- the service SHOULD return a <forbidden/> error to the occupant module:hook("muc-pre-invite", function(event) local room = event.room; if get_members_only(room) then local stanza = event.stanza; local inviter_affiliation = room:get_affiliation(stanza.attr.from) or "none"; local required_affiliation = room._data.allow_member_invites and "member" or "admin"; if valid_affiliations[inviter_affiliation] < valid_affiliations[required_affiliation] then event.origin.send(st.error_reply(stanza, "auth", "forbidden", nil, room.jid)); return true; end end end); -- When an invite is sent; add an affiliation for the invitee module:hook("muc-invite", function(event) local room = event.room; if get_members_only(room) then local stanza = event.stanza; local invitee = stanza.attr.to; local affiliation = room:get_affiliation(invitee); local invited_unaffiliated = valid_affiliations[affiliation or "none"] <= valid_affiliations.none; if invited_unaffiliated then local from = stanza:get_child("x", "http://jabber.org/protocol/muc#user") :get_child("invite").attr.from; module:log("debug", "%s invited %s into members only room %s, granting membership", from, invitee, room.jid); -- This might fail; ignore for now room:set_affiliation(true, invitee, "member", "Invited by " .. from); room:save(); end end end); return { get = get_members_only; set = set_members_only; get_allow_member_invites = get_allow_member_invites; set_allow_member_invites = set_allow_member_invites; };