Software / code / prosody
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util/dataforms.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 | 12975:d10957394a3c |
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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 setmetatable = setmetatable; local ipairs = ipairs; local type, next = type, next; local tonumber = tonumber; local tostring = tostring; local t_concat = table.concat; local st = require "prosody.util.stanza"; local jid_prep = require "prosody.util.jid".prep; local datetime = require "prosody.util.datetime"; local _ENV = nil; -- luacheck: std none local xmlns_forms = 'jabber:x:data'; local xmlns_validate = 'http://jabber.org/protocol/xdata-validate'; local form_t = {}; local form_mt = { __index = form_t }; local function new(layout) return setmetatable(layout, form_mt); end function form_t.form(layout, data, formtype) if not formtype then formtype = "form" end local form = st.stanza("x", { xmlns = xmlns_forms, type = formtype }); if formtype == "cancel" then return form; end if formtype ~= "submit" then if layout.title then form:tag("title"):text(layout.title):up(); end if layout.instructions then form:tag("instructions"):text(layout.instructions):up(); end end for _, field in ipairs(layout) do local field_type = field.type or "text-single"; -- Add field tag form:tag("field", { type = field_type, var = field.var or field.name, label = formtype ~= "submit" and field.label or nil }); if formtype ~= "submit" then if field.desc then form:text_tag("desc", field.desc); end end if formtype == "form" and field.datatype then form:tag("validate", { xmlns = xmlns_validate, datatype = field.datatype }); if field.range_min or field.range_max then form:tag("range", { min = field.range_min and tostring(field.range_min), max = field.range_max and tostring(field.range_max), }):up(); end -- <basic/> assumed form:up(); end local value = field.value; local options = field.options; if data and data[field.name] ~= nil then value = data[field.name]; if formtype == "form" and type(value) == "table" and (field_type == "list-single" or field_type == "list-multi") then -- Allow passing dynamically generated options as values options, value = value, nil; end end if formtype == "form" and options then local defaults = {}; for _, val in ipairs(options) do if type(val) == "table" then form:tag("option", { label = val.label }):tag("value"):text(val.value):up():up(); if val.default then defaults[#defaults+1] = val.value; end else form:tag("option", { label= val }):tag("value"):text(val):up():up(); end end if not value then if field_type == "list-single" then value = defaults[1]; elseif field_type == "list-multi" then value = defaults; end end end if value ~= nil then if type(value) == "number" then if field.datatype == "xs:dateTime" then value = datetime.datetime(value); elseif field_type == "boolean" then value = value ~= 0; elseif field.datatype == "xs:double" or field.datatype == "xs:decimal" then value = ("%f"):format(value); else value = ("%d"):format(value); end end -- Add value, depending on type if field_type == "hidden" then if type(value) == "table" then -- Assume an XML snippet form:tag("value") :add_child(value) :up(); else form:tag("value"):text(value):up(); end elseif field_type == "boolean" then form:tag("value"):text((value and "1") or "0"):up(); elseif field_type == "fixed" then form:tag("value"):text(value):up(); elseif field_type == "jid-multi" then for _, jid in ipairs(value) do form:tag("value"):text(jid):up(); end elseif field_type == "jid-single" then form:tag("value"):text(value):up(); elseif field_type == "text-single" or field_type == "text-private" then form:tag("value"):text(value):up(); elseif field_type == "text-multi" then -- Split into multiple <value> tags, one for each line for line in value:gmatch("([^\r\n]+)\r?\n*") do form:tag("value"):text(line):up(); end elseif field_type == "list-single" then form:tag("value"):text(value):up(); elseif field_type == "list-multi" then for _, val in ipairs(value) do form:tag("value"):text(val):up(); end end end local media = field.media; if media then form:tag("media", { xmlns = "urn:xmpp:media-element", height = ("%d"):format(media.height), width = ("%d"):format(media.width) }); for _, val in ipairs(media) do form:tag("uri", { type = val.type }):text(val.uri):up() end form:up(); end if formtype == "form" and field.required then form:tag("required"):up(); end -- Jump back up to list of fields form:up(); end return form; end local field_readers = {}; local data_validators = {}; function form_t.data(layout, stanza, current) local data = {}; local errors = {}; local present = {}; for _, field in ipairs(layout) do local tag; for field_tag in stanza:childtags("field") do if (field.var or field.name) == field_tag.attr.var then tag = field_tag; break; end end if not tag then if current and current[field.name] ~= nil then data[field.name] = current[field.name]; elseif field.required then errors[field.name] = "Required value missing"; end elseif field.name then present[field.name] = true; local reader = field_readers[field.type]; if reader then local value, err = reader(tag, field.required); local validator = field.datatype and data_validators[field.datatype]; if value ~= nil and validator then local valid, ret = validator(value, field); if valid then value = ret; else value, err = nil, ret or ("Invalid value for data of type " .. field.datatype); end end data[field.name], errors[field.name] = value, err; end end end if next(errors) then return data, errors, present; end return data, nil, present; end local function simple_text(field_tag, required) local data = field_tag:get_child_text("value"); -- XEP-0004 does not say if an empty string is acceptable for a required value -- so we will follow HTML5 which says that empty string means missing if required and (data == nil or data == "") then return nil, "Required value missing"; end return data; -- Return whatever get_child_text returned, even if empty string end field_readers["text-single"] = simple_text; field_readers["text-private"] = simple_text; field_readers["jid-single"] = function (field_tag, required) local raw_data, err = simple_text(field_tag, required); if not raw_data then return raw_data, err; end local data = jid_prep(raw_data); if not data then return nil, "Invalid JID: " .. raw_data; end return data; end field_readers["jid-multi"] = function (field_tag, required) local result = {}; local err = {}; for value_tag in field_tag:childtags("value") do local raw_value = value_tag:get_text(); local value = jid_prep(raw_value); result[#result+1] = value; if raw_value and not value then err[#err+1] = ("Invalid JID: " .. raw_value); end end if #result > 0 then return result, (#err > 0 and t_concat(err, "\n") or nil); elseif required then return nil, "Required value missing"; end end field_readers["list-multi"] = function (field_tag, required) local result = {}; for value in field_tag:childtags("value") do result[#result+1] = value:get_text(); end if #result > 0 then return result; elseif required then return nil, "Required value missing"; end end field_readers["text-multi"] = function (field_tag, required) local data, err = field_readers["list-multi"](field_tag, required); if data then data = t_concat(data, "\n"); end return data, err; end field_readers["list-single"] = simple_text; local boolean_values = { ["1"] = true, ["true"] = true, ["0"] = false, ["false"] = false, }; field_readers["boolean"] = function (field_tag, required) local raw_value, err = simple_text(field_tag, required); if not raw_value then return raw_value, err; end local value = boolean_values[raw_value]; if value == nil then return nil, "Invalid boolean representation:" .. raw_value; end return value; end field_readers["hidden"] = function (field_tag) return field_tag:get_child_text("value"); end data_validators["xs:integer"] = function (data, field) local n = tonumber(data); if not n then return false, "not a number"; elseif n % 1 ~= 0 then return false, "not an integer"; end if field.range_max and n > field.range_max then return false, "out of bounds"; elseif field.range_min and n < field.range_min then return false, "out of bounds"; end return true, n; end data_validators["pubsub:integer-or-max"] = function (data, field) if data == "max" then return true, data; else return data_validators["xs:integer"](data, field); end end data_validators["xs:dateTime"] = function(data, field) -- luacheck: ignore 212/field local n = datetime.parse(data); if not n then return false, "invalid timestamp"; end return true, n; end local function get_form_type(form) if not st.is_stanza(form) then return nil, "not a stanza object"; elseif form.attr.xmlns ~= "jabber:x:data" or form.name ~= "x" then return nil, "not a dataform element"; end for field in form:childtags("field") do if field.attr.var == "FORM_TYPE" then return field:get_child_text("value"); end end return ""; end return { new = new; get_type = get_form_type; }; --[=[ Layout: { title = "MUC Configuration", instructions = [[Use this form to configure options for this MUC room.]], { name = "FORM_TYPE", type = "hidden", required = true }; { name = "field-name", type = "field-type", required = false }; } --]=]