Software / code / prosody
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plugins/mod_register_ibr.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 | 13232:e0ab20519ce5 |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- -- 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 dataform_new = require "prosody.util.dataforms".new; local usermanager_user_exists = require "prosody.core.usermanager".user_exists; local usermanager_create_user_with_role = require "prosody.core.usermanager".create_user_with_role; local usermanager_set_password = require "prosody.core.usermanager".create_user; local usermanager_delete_user = require "prosody.core.usermanager".delete_user; local nodeprep = require "prosody.util.encodings".stringprep.nodeprep; local util_error = require "prosody.util.error"; local additional_fields = module:get_option_array("additional_registration_fields", {}); local require_encryption = module:get_option_boolean("c2s_require_encryption", module:get_option_boolean("require_encryption", true)); local default_role = module:get_option_string("register_ibr_default_role", "prosody:registered"); pcall(function () module:depends("register_limits"); end); local account_details = module:open_store("account_details"); local field_map = { FORM_TYPE = { name = "FORM_TYPE", type = "hidden", value = "jabber:iq:register" }; username = { name = "username", type = "text-single", label = "Username", required = true }; password = { name = "password", type = "text-private", label = "Password", required = true }; nick = { name = "nick", type = "text-single", label = "Nickname" }; name = { name = "name", type = "text-single", label = "Full Name" }; first = { name = "first", type = "text-single", label = "Given Name" }; last = { name = "last", type = "text-single", label = "Family Name" }; email = { name = "email", type = "text-single", label = "Email" }; address = { name = "address", type = "text-single", label = "Street" }; city = { name = "city", type = "text-single", label = "City" }; state = { name = "state", type = "text-single", label = "State" }; zip = { name = "zip", type = "text-single", label = "Postal code" }; phone = { name = "phone", type = "text-single", label = "Telephone number" }; url = { name = "url", type = "text-single", label = "Webpage" }; date = { name = "date", type = "text-single", label = "Birth date" }; }; local title = module:get_option_string("registration_title", "Creating a new account"); local instructions = module:get_option_string("registration_instructions", "Choose a username and password for use with this service."); local registration_form = dataform_new{ title = title; instructions = instructions; field_map.FORM_TYPE; field_map.username; field_map.password; }; local registration_query = st.stanza("query", {xmlns = "jabber:iq:register"}) :tag("instructions"):text(instructions):up() :tag("username"):up() :tag("password"):up(); for _, field in ipairs(additional_fields) do if type(field) == "table" then registration_form[#registration_form + 1] = field; elseif field_map[field] or field_map[field:sub(1, -2)] then if field:match("%+$") then field = field:sub(1, -2); field_map[field].required = true; end registration_form[#registration_form + 1] = field_map[field]; registration_query:tag(field):up(); else module:log("error", "Unknown field %q", field); end end registration_query:add_child(registration_form:form()); local register_stream_feature = st.stanza("register", {xmlns="http://jabber.org/features/iq-register"}):up(); module:hook("stream-features", function(event) local session, features = event.origin, event.features; -- Advertise registration to unauthorized clients only. if session.type ~= "c2s_unauthed" or (require_encryption and not session.secure) then return end features:add_child(register_stream_feature); end); local function parse_response(query) local form = query:get_child("x", "jabber:x:data"); if form then return registration_form:data(form); else local data = {}; local errors = {}; for _, field in ipairs(registration_form) do local name, required = field.name, field.required; if field_map[name] then data[name] = query:get_child_text(name); if (not data[name] or #data[name] == 0) and required then errors[name] = "Required value missing"; end end end if next(errors) then return data, errors; end return data; end end -- In-band registration module:hook("stanza/iq/jabber:iq:register:query", function(event) local session, stanza = event.origin, event.stanza; local log = session.log or module._log; if session.type ~= "c2s_unauthed" then log("debug", "Attempted registration when disabled or already authenticated"); session.send(st.error_reply(stanza, "cancel", "service-unavailable")); return true; end if require_encryption and not session.secure then session.send(st.error_reply(stanza, "modify", "policy-violation", "Encryption is required")); return true; end local query = stanza.tags[1]; if stanza.attr.type == "get" then local reply = st.reply(stanza); reply:add_child(registration_query); session.send(reply); return true; end -- stanza.attr.type == "set" if query.tags[1] and query.tags[1].name == "remove" then session.send(st.error_reply(stanza, "auth", "registration-required")); return true; end local data, errors = parse_response(query); if errors then log("debug", "Error parsing registration form:"); local textual_errors = {}; for field, err in pairs(errors) do log("debug", "Field %q: %s", field, err); table.insert(textual_errors, ("%s: %s"):format(field:gsub("^%a", string.upper), err)); end session.send(st.error_reply(stanza, "modify", "not-acceptable", table.concat(textual_errors, "\n"))); return true; end local username, password = nodeprep(data.username, true), data.password; data.username, data.password = nil, nil; local host = module.host; if not username or username == "" then log("debug", "The requested username is invalid."); session.send(st.error_reply(stanza, "modify", "not-acceptable", "The requested username is invalid.")); return true; end local user = { username = username, password = password, host = host; additional = data, ip = session.ip, session = session; role = default_role; allowed = true; }; module:fire_event("user-registering", user); if not user.allowed then local error_type, error_condition, reason; local err = user.error; if err then error_type, error_condition, reason = err.type, err.condition, err.text; else -- COMPAT pre-util.error error_type, error_condition, reason = user.error_type, user.error_condition, user.reason; end log("debug", "Registration disallowed by module: %s", reason or "no reason given"); session.send(st.error_reply(stanza, error_type or "modify", error_condition or "not-acceptable", reason)); return true; end if usermanager_user_exists(username, host) then if user.allow_reset == username then local ok, err = util_error.coerce(usermanager_set_password(username, password, host)); if ok then module:fire_event("user-password-reset", user); session.send(st.reply(stanza)); -- reset ok! else session.log("error", "Unable to reset password for %s@%s: %s", username, host, err); session.send(st.error_reply(stanza, err.type, err.condition, err.text)); end return true; else log("debug", "Attempt to register with existing username"); session.send(st.error_reply(stanza, "cancel", "conflict", "The requested username already exists.")); return true; end end local created, err = usermanager_create_user_with_role(username, password, host, user.role); if created then data.registered = os.time(); if not account_details:set(username, data) then log("debug", "Could not store extra details"); usermanager_delete_user(username, host); session.send(st.error_reply(stanza, "wait", "internal-server-error", "Failed to write data to disk.")); return true; end session.send(st.reply(stanza)); -- user created! log("info", "User account created: %s@%s", username, host); module:fire_event("user-registered", { username = username, host = host, source = "mod_register", session = session }); else log("debug", "Could not create user", err); session.send(st.error_reply(stanza, "cancel", "feature-not-implemented", err)); end return true; end);