File

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 };
}


--]=]