Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/util/prosodyctl/cert.lua	Tue Jun 02 08:01:21 2020 +0100
@@ -0,0 +1,293 @@
+local lfs = require "lfs";
+
+local pctl = require "util.prosodyctl";
+local configmanager = require "core.configmanager";
+
+local openssl;
+
+local cert_commands = {};
+
+-- If a file already exists, ask if the user wants to use it or replace it
+-- Backups the old file if replaced
+local function use_existing(filename)
+	local attrs = lfs.attributes(filename);
+	if attrs then
+		if pctl.show_yesno(filename .. " exists, do you want to replace it? [y/n]") then
+			local backup = filename..".bkp~"..os.date("%FT%T", attrs.change);
+			os.rename(filename, backup);
+			pctl.show_message("%s backed up to %s", filename, backup);
+		else
+			-- Use the existing file
+			return true;
+		end
+	end
+end
+
+local have_pposix, pposix = pcall(require, "util.pposix");
+local cert_basedir = prosody.paths.data == "." and "./certs" or prosody.paths.data;
+if have_pposix and pposix.getuid() == 0 then
+	-- FIXME should be enough to check if this directory is writable
+	local cert_dir = configmanager.get("*", "certificates") or "certs";
+	cert_basedir = configmanager.resolve_relative_path(prosody.paths.config, cert_dir);
+end
+
+function cert_commands.config(arg)
+	if #arg >= 1 and arg[1] ~= "--help" then
+		local conf_filename = cert_basedir .. "/" .. arg[1] .. ".cnf";
+		if use_existing(conf_filename) then
+			return nil, conf_filename;
+		end
+		local distinguished_name;
+		if arg[#arg]:find("^/") then
+			distinguished_name = table.remove(arg);
+		end
+		local conf = openssl.config.new();
+		conf:from_prosody(prosody.hosts, configmanager, arg);
+		if distinguished_name then
+			local dn = {};
+			for k, v in distinguished_name:gmatch("/([^=/]+)=([^/]+)") do
+				table.insert(dn, k);
+				dn[k] = v;
+			end
+			conf.distinguished_name = dn;
+		else
+			pctl.show_message("Please provide details to include in the certificate config file.");
+			pctl.show_message("Leave the field empty to use the default value or '.' to exclude the field.")
+			for _, k in ipairs(openssl._DN_order) do
+				local v = conf.distinguished_name[k];
+				if v then
+					local nv = nil;
+					if k == "commonName" then
+						v = arg[1]
+					elseif k == "emailAddress" then
+						v = "xmpp@" .. arg[1];
+					elseif k == "countryName" then
+						local tld = arg[1]:match"%.([a-z]+)$";
+						if tld and #tld == 2 and tld ~= "uk" then
+							v = tld:upper();
+						end
+					end
+					nv = pctl.show_prompt(("%s (%s):"):format(k, nv or v));
+					nv = (not nv or nv == "") and v or nv;
+					if nv:find"[\192-\252][\128-\191]+" then
+						conf.req.string_mask = "utf8only"
+					end
+					conf.distinguished_name[k] = nv ~= "." and nv or nil;
+				end
+			end
+		end
+		local conf_file, err = io.open(conf_filename, "w");
+		if not conf_file then
+			pctl.show_warning("Could not open OpenSSL config file for writing");
+			pctl.show_warning(err);
+			os.exit(1);
+		end
+		conf_file:write(conf:serialize());
+		conf_file:close();
+		print("");
+		pctl.show_message("Config written to %s", conf_filename);
+		return nil, conf_filename;
+	else
+		pctl.show_usage("cert config HOSTNAME [HOSTNAME+]", "Builds a certificate config file covering the supplied hostname(s)")
+	end
+end
+
+function cert_commands.key(arg)
+	if #arg >= 1 and arg[1] ~= "--help" then
+		local key_filename = cert_basedir .. "/" .. arg[1] .. ".key";
+		if use_existing(key_filename) then
+			return nil, key_filename;
+		end
+		os.remove(key_filename); -- This file, if it exists is unlikely to have write permissions
+		local key_size = tonumber(arg[2] or pctl.show_prompt("Choose key size (2048):") or 2048);
+		local old_umask = pposix.umask("0377");
+		if openssl.genrsa{out=key_filename, key_size} then
+			os.execute(("chmod 400 '%s'"):format(key_filename));
+			pctl.show_message("Key written to %s", key_filename);
+			pposix.umask(old_umask);
+			return nil, key_filename;
+		end
+		pctl.show_message("There was a problem, see OpenSSL output");
+	else
+		pctl.show_usage("cert key HOSTNAME <bits>", "Generates a RSA key named HOSTNAME.key\n "
+		.."Prompts for a key size if none given")
+	end
+end
+
+function cert_commands.request(arg)
+	if #arg >= 1 and arg[1] ~= "--help" then
+		local req_filename = cert_basedir .. "/" .. arg[1] .. ".req";
+		if use_existing(req_filename) then
+			return nil, req_filename;
+		end
+		local _, key_filename = cert_commands.key({arg[1]});
+		local _, conf_filename = cert_commands.config(arg);
+		if openssl.req{new=true, key=key_filename, utf8=true, sha256=true, config=conf_filename, out=req_filename} then
+			pctl.show_message("Certificate request written to %s", req_filename);
+		else
+			pctl.show_message("There was a problem, see OpenSSL output");
+		end
+	else
+		pctl.show_usage("cert request HOSTNAME [HOSTNAME+]", "Generates a certificate request for the supplied hostname(s)")
+	end
+end
+
+function cert_commands.generate(arg)
+	if #arg >= 1 and arg[1] ~= "--help" then
+		local cert_filename = cert_basedir .. "/" .. arg[1] .. ".crt";
+		if use_existing(cert_filename) then
+			return nil, cert_filename;
+		end
+		local _, key_filename = cert_commands.key({arg[1]});
+		local _, conf_filename = cert_commands.config(arg);
+		if key_filename and conf_filename and cert_filename
+			and openssl.req{new=true, x509=true, nodes=true, key=key_filename,
+				days=365, sha256=true, utf8=true, config=conf_filename, out=cert_filename} then
+			pctl.show_message("Certificate written to %s", cert_filename);
+			print();
+		else
+			pctl.show_message("There was a problem, see OpenSSL output");
+		end
+	else
+		pctl.show_usage("cert generate HOSTNAME [HOSTNAME+]", "Generates a self-signed certificate for the current hostname(s)")
+	end
+end
+
+local function sh_esc(s)
+	return "'" .. s:gsub("'", "'\\''") .. "'";
+end
+
+local function copy(from, to, umask, owner, group)
+	local old_umask = umask and pposix.umask(umask);
+	local attrs = lfs.attributes(to);
+	if attrs then -- Move old file out of the way
+		local backup = to..".bkp~"..os.date("%FT%T", attrs.change);
+		os.rename(to, backup);
+	end
+	-- FIXME friendlier error handling, maybe move above backup back?
+	local input = assert(io.open(from));
+	local output = assert(io.open(to, "w"));
+	local data = input:read(2^11);
+	while data and output:write(data) do
+		data = input:read(2^11);
+	end
+	assert(input:close());
+	assert(output:close());
+	if not prosody.installed then
+		-- FIXME this is possibly specific to GNU chown
+		os.execute(("chown -c --reference=%s %s"):format(sh_esc(cert_basedir), sh_esc(to)));
+	elseif owner and group then
+		local ok = os.execute(("chown %s:%s %s"):format(sh_esc(owner), sh_esc(group), sh_esc(to)));
+		assert(ok == true or ok == 0, "Failed to change ownership of "..to);
+	end
+	if old_umask then pposix.umask(old_umask); end
+	return true;
+end
+
+function cert_commands.import(arg)
+	local hostnames = {};
+	-- Move hostname arguments out of arg, the rest should be a list of paths
+	while arg[1] and prosody.hosts[ arg[1] ] do
+		table.insert(hostnames, table.remove(arg, 1));
+	end
+	if hostnames[1] == nil then
+		local domains = os.getenv"RENEWED_DOMAINS"; -- Set if invoked via certbot
+		if domains then
+			for host in domains:gmatch("%S+") do
+				table.insert(hostnames, host);
+			end
+		else
+			for host in pairs(prosody.hosts) do
+				if host ~= "*" and configmanager.get(host, "enabled") ~= false then
+					table.insert(hostnames, host);
+				end
+			end
+		end
+	end
+	if not arg[1] or arg[1] == "--help" then -- Probably forgot the path
+		pctl.show_usage("cert import [HOSTNAME+] /path/to/certs [/other/paths/]+",
+			"Copies certificates to "..cert_basedir);
+		return 1;
+	end
+	local owner, group;
+	if pposix.getuid() == 0 then -- We need root to change ownership
+		owner = configmanager.get("*", "prosody_user") or "prosody";
+		group = configmanager.get("*", "prosody_group") or owner;
+	end
+	local cm = require "core.certmanager";
+	local imported = {};
+	for _, host in ipairs(hostnames) do
+		for _, dir in ipairs(arg) do
+			local paths = cm.find_cert(dir, host);
+			if paths then
+				copy(paths.certificate, cert_basedir .. "/" .. host .. ".crt", nil, owner, group);
+				copy(paths.key, cert_basedir .. "/" .. host .. ".key", "0377", owner, group);
+				table.insert(imported, host);
+			else
+				-- TODO Say where we looked
+				pctl.show_warning("No certificate for host "..host.." found :(");
+			end
+			-- TODO Additional checks
+			-- Certificate names matches the hostname
+			-- Private key matches public key in certificate
+		end
+	end
+	if imported[1] then
+		pctl.show_message("Imported certificate and key for hosts %s", table.concat(imported, ", "));
+		local ok, err = pctl.reload();
+		if not ok and err ~= "not-running" then
+			pctl.show_message(pctl.error_messages[err]);
+		end
+	else
+		pctl.show_warning("No certificates imported :(");
+		return 1;
+	end
+end
+
+local function cert(arg)
+	if #arg >= 1 and arg[1] ~= "--help" then
+		openssl = require "util.openssl";
+		lfs = require "lfs";
+		local cert_dir_attrs = lfs.attributes(cert_basedir);
+		if not cert_dir_attrs then
+			pctl.show_warning("The directory "..cert_basedir.." does not exist");
+			return 1; -- TODO Should we create it?
+		end
+		local uid = pposix.getuid();
+		if uid ~= 0 and uid ~= cert_dir_attrs.uid then
+			pctl.show_warning("The directory "..cert_basedir.." is not owned by the current user, won't be able to write files to it");
+			return 1;
+		elseif not cert_dir_attrs.permissions then -- COMPAT with LuaFilesystem < 1.6.2 (hey CentOS!)
+			pctl.show_message("Unable to check permissions on %s (LuaFilesystem 1.6.2+ required)", cert_basedir);
+			pctl.show_message("Please confirm that Prosody (and only Prosody) can write to this directory)");
+		elseif cert_dir_attrs.permissions:match("^%.w..%-..%-.$") then
+			pctl.show_warning("The directory "..cert_basedir.." not only writable by its owner");
+			return 1;
+		end
+		local subcmd = table.remove(arg, 1);
+		if type(cert_commands[subcmd]) == "function" then
+			if subcmd ~= "import" then -- hostnames are optional for import
+				if not arg[1] then
+					pctl.show_message"You need to supply at least one hostname"
+					arg = { "--help" };
+				end
+				if arg[1] ~= "--help" and not prosody.hosts[arg[1]] then
+					pctl.show_message(pctl.error_messages["no-such-host"]);
+					return 1;
+				end
+			end
+			return cert_commands[subcmd](arg);
+		elseif subcmd == "check" then
+			return require "util.prosodyctl.check".check({"certs"});
+		end
+	end
+	pctl.show_usage("cert config|request|generate|key|import", "Helpers for generating X.509 certificates and keys.")
+	for _, cmd in pairs(cert_commands) do
+		print()
+		cmd{ "--help" }
+	end
+end
+
+return {
+	cert = cert;
+};