Implement server discovery (.well-known/matrix/client), and re-authenticate if access token expired or was invalidated somehow

matrix-send

@@ -19,11 +19,11 @@
 
 require "luarocks.loader"
 getopt = require "posix.unistd".getopt
-mkdir = require "posix.sys.stat".mkdir
+ mkdir = require "posix.sys.stat".mkdir
-bname = require "posix.libgen".basename
+ bname = require "posix.libgen".basename
-http = require "socket.http"
+  http = require "socket.http"
-cjson = require "cjson"
+ cjson = require "cjson"
-ltn12 = require "ltn12"
+ ltn12 = require "ltn12"
 
  version = "2.0"
  confdir = string.gsub("~/.config/matrix-send", '~', os.getenv("HOME"), 1)
@@ -31,7 +31,8 @@ confpath = confdir .. "/config.lua"
 confvarv = os.getenv("MATRIXSEND_CONFIG")
 hostname = io.input("/etc/hostname"):read("l")
 
-json = {}
+matrix = {}
+  json = {}
    uri = {}
     sh = os.execute
 
@@ -50,38 +51,6 @@ function fileexists(file)
 	end
 end
 
--- Makes an HTTP POST request to uri and sends body. Returns the output of the HTTP server.
-function post(uri, body)
-	local respbody = {} -- for the response body
-	local result, respcode, respheaders, respstatus = http.request {
-			method = "POST",
-			url = uri,
-			source = ltn12.source.string(body),
-			headers = {
-					["content-type"] = "application/json",
-					["content-length"] = tostring(#body)
-			},
-			sink = ltn12.sink.table(respbody)
-	}
-	return table.concat(respbody)
-end
-
--- Makes an HTTP PUT request to uri and sends body. Returns the output of the HTTP server.
-function put(uri, body)
-	local respbody = {} -- for the response body
-	local result, respcode, respheaders, respstatus = http.request {
-			method = "PUT",
-			url = uri,
-			source = ltn12.source.string(body),
-			headers = {
-					["content-type"] = "application/json",
-					["content-length"] = tostring(#body)
-			},
-			sink = ltn12.sink.table(respbody)
-	}
-	return table.concat(respbody)
-end
-
 -- Prints a message to stdout in the following format:
 -- matrix-send: s
 function msg(s)
@@ -104,20 +73,87 @@ function confpanic(s)
 	os.exit(1)
 end
 
+------------------------
+--- Matrix functions ---
+------------------------
+
+function matrix.login(uri, json)
+	local respbody = {}
+	local result, respcode, respheaders, respstatus = http.request {
+			method = "POST",
+			url = uri,
+			source = ltn12.source.string(json),
+			headers = {
+					["content-type"] = "application/json",
+					["content-length"] = tostring(#json)
+			},
+			sink = ltn12.sink.table(respbody)
+	}
+	local body = table.concat(respbody)
+	local t = cjson.decode(body)
+	if t.error then
+		panic("server: " .. t.error)
+	else
+		return t.access_token
+	end
+end
+
+function matrix.send(uri, json, login_uri, login_json)
+	local respbody = {}
+	local result, respcode, respheaders, respstatus = http.request {
+			method = "PUT",
+			url = uri,
+			source = ltn12.source.string(json),
+			headers = {
+					["content-type"] = "application/json",
+					["content-length"] = tostring(#json)
+			},
+			sink = ltn12.sink.table(respbody)
+	}
+	local body = table.concat(respbody)
+	local t = cjson.decode(body)
+	if t.error then
+		if t.errcode == "M_UNKNOWN_TOKEN" then
+			msg("token expired/invalidated; re-authenticating")
+			-- I mean, it works
+			t = setmetatable({}, {
+				__concat = function(left, right)
+					if type(left) == "string" then
+						return left .. tostring(right)
+					end
+					return tostring(left) .. tostring(right)
+				end
+			})
+			t.token = matrix.login(login_uri, login_json)
+			if not cache.disable then
+				mkdir(cache.location)
+				cf = io.open(cache.location .. "/token", 'w+')
+				cf:write(t.token)
+				cf:close()
+			end
+			matrix.send(string.gsub(uri, "access_token=.+", "access_token=" .. t.token), json, login_uri, login_json)
+		else
+			panic("server: " .. t.error)
+		end
+	else
+		return t
+	end
+end
+
 -- Default configuration file
 default_config = [[
 -- Default configuration file for matrix-send
 -- In comments, here is a simple example configuration.
 
 --login = {
---	server = "matrix.envs.net",
+--	server = "envs.net",
 --	username = "john",
 --	password = "examplepassword
 --}
 
 -- You could also do it this way:
 
---login.server = "matrix.envs.net"
+--login.server = "envs.net"
 --login.username = "john"
 --login.password = "examplepassword"
 
@@ -242,9 +278,29 @@ else
 	txnid = 0
 end
 
-uri.login = string.format("https://%s/_matrix/client/v3/login", login.server)
+-- Get .well-known
+uri.well_known = string.format("https://%s/.well-known/matrix/client", login.server)
+wellknown_body, errno = http.request(uri.well_known)
+if errno ~= 200 then
+	panic("server: Error " .. errno .. " while getting /.well-known/matrix/client")
+end
+wellknown_t = cjson.decode(wellknown_body)
+login.server = wellknown_t["m.homeserver"].base_url
+
+-- Assign URIs and JSON bodies
+uri.login = string.format("%s/_matrix/client/v3/login", login.server)
+json.login = string.format([[
+{
+	"identifier": {
+		"type": "m.id.user",
+		"user": "%s"
+	},
+	"initial_device_display_name": "matrix-send@%s",
+	"password": "%s",
+	"type": "m.login.password"
+}
+]], login.username, hostname, login.password)
 
--- Assemble various JSON messages
 json.message = string.format([[
 {
 	"body": "%s",
@@ -259,33 +315,8 @@ if not login.token then
 		login.token = cf:read('l')
 		cf:close()
 	else
-		-- json.login should only be assigned if it needs to be assigned
+		-- Login
-		json.login = string.format([[
+		login.token = matrix.login(uri.login, json.login)
-		{
-			"identifier": {
-				"type": "m.id.user",
-				"user": "%s"
-			},
-			"initial_device_display_name": "matrix-send@%s",
-			"password": "%s",
-			"type": "m.login.password"
-		}
-
-		]], login.username, hostname, login.password)
-
-		-- Send the request!
-		local body = post(uri.login, json.login)
-
-		-- What else do I call it?
-		local t = cjson.decode(body)
-
-		-- If there was a server side error, print the error and exit.
-		if t.error then
-			panic(login.server .. ": " .. t.error)
-		end
-
-		-- Log the access token
-		login.token = t.access_token
 
 		-- Cache the access token
 		if not cache.disable then
@@ -297,15 +328,11 @@ if not login.token then
 	end
 end
 
-uri.message = string.format("https://%s/_matrix/client/v3/rooms/%s/send/m.room.message/%d?access_token=%s",
+uri.message = string.format("%s/_matrix/client/v3/rooms/%s/send/m.room.message/%d?access_token=%s",
 	login.server, room_id, txnid, login.token)
 
 -- Send the message!
-body = put(uri.message, json.message)
+matrix.send(uri.message, json.message, uri.login, json.login)
-t = cjson.decode(body)
-if t.error then
-	panic(login.server .. ": " .. t.error)
-end
 
 -- Increment txnid and cache
 if not cache.disable then