Ability to authenticate users by nickname↔password database

README

@@ -28,6 +28,7 @@ But it has some convincing features:
 * Optional permanent channel's state saving in plain text files
   (so you can reload daemon and all channels topics and keys won't
   disappear)
+* Optional ability to authenticate users by nickname↔password
 
 Some remarks and recommendations related to it's simplicity:
 
@@ -36,7 +37,7 @@ Some remarks and recommendations related to it's simplicity:
 
 SUPPORTED IRC COMMANDS
 
-* NICK/USER during registration workflow
+* PASS/NICK/USER during registration workflow
 * PING/PONGs
 * NOTICE/PRIVMSG
 * MOTD, LUSERS, WHO, WHOIS, QUIT
@@ -56,8 +57,22 @@ Just execute goircd daemon. It has following optional arguments:
              loaded during startup. If omitted, then states will be
              lost after daemon termination
 * -tls_key/-tls_cert: enable TLS and specify key and certificate file
+* -passwords: enable client authentication and specify path to
+              passwords file
 * -verbose: increase log messages verbosity
 
+AUTHENTICATION
+
+You can turn on optional client authentication by preparing passwords
+file and using the -passwords argument. Format of passwords file is:
+
+    login1:password1\n
+    login2:password2\n
+    …
+
+You can force rereading of passwords file without server interruption by
+sending HUP signal to him.
+
 LICENCE
 
 This program is free software: you can redistribute it and/or modify

client.go

@@ -37,6 +37,7 @@ type Client struct {
 	nickname   string
 	username   string
 	realname   string
+	password   string
 }
 
 type ClientAlivenessState struct {
@@ -49,7 +50,7 @@ func (client Client) String() string {
 }
 
 func NewClient(hostname string, conn net.Conn) *Client {
-	return &Client{hostname: hostname, conn: conn, nickname: "*"}
+	return &Client{hostname: hostname, conn: conn, nickname: "*", password: ""}
 }
 
 // Client processor blockingly reads everything remote client sends,
@@ -64,7 +65,6 @@ func (client *Client) Processor(sink chan<- ClientEvent) {
 		bufNet = make([]byte, BufSize)
 		_, err := client.conn.Read(bufNet)
 		if err != nil {
-			log.Println(client, "connection lost", err)
 			sink <- ClientEvent{client, EventDel, ""}
 			break
 		}

daemon.go

@@ -25,6 +25,7 @@ import (
 	"regexp"
 	"sort"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -38,6 +39,8 @@ var (
 	RENickname = regexp.MustCompile("^[a-zA-Z0-9-]{1,9}$")
 )
 
+var passwordsRefreshLock sync.Mutex
+
 type Daemon struct {
 	Verbose            bool
 	hostname           string
@@ -49,6 +52,7 @@ type Daemon struct {
 	lastAlivenessCheck time.Time
 	logSink            chan<- LogEvent
 	stateSink          chan<- StateEvent
+	passwords          map[string]string
 }
 
 func NewDaemon(hostname, motd string, logSink chan<- LogEvent, stateSink chan<- StateEvent) *Daemon {
@@ -154,6 +158,12 @@ func (daemon *Daemon) SendList(client *Client, cols []string) {
 // When client finishes NICK/USER workflow, then MOTD and LUSERS are send to him.
 func (daemon *Daemon) ClientRegister(client *Client, command string, cols []string) {
 	switch command {
+	case "PASS":
+		if len(cols) == 1 || len(cols[1]) < 1 {
+			client.ReplyNotEnoughParameters("PASS")
+			return
+		}
+		client.password = cols[1]
 	case "NICK":
 		if len(cols) == 1 || len(cols[1]) < 1 {
 			client.ReplyParts("431", "No nickname given")
@@ -185,6 +195,14 @@ func (daemon *Daemon) ClientRegister(client *Client, command string, cols []stri
 		client.realname = strings.TrimLeft(args[3], ":")
 	}
 	if client.nickname != "*" && client.username != "" {
+		passwordsRefreshLock.Lock()
+		if daemon.passwords != nil && (client.password == "" || daemon.passwords[client.nickname] != client.password) {
+			passwordsRefreshLock.Unlock()
+			client.ReplyParts("462", "You may not register")
+			client.conn.Close()
+			return
+		}
+		passwordsRefreshLock.Unlock()
 		client.registered = true
 		client.ReplyNicknamed("001", "Hi, welcome to IRC")
 		client.ReplyNicknamed("002", "Your host is "+daemon.hostname+", running goircd")
@@ -192,6 +210,7 @@ func (daemon *Daemon) ClientRegister(client *Client, command string, cols []stri
 		client.ReplyNicknamed("004", daemon.hostname+" goircd o o")
 		daemon.SendLusers(client)
 		daemon.SendMotd(client)
+		log.Println(client, "logged in")
 	}
 }
 
@@ -247,6 +266,7 @@ func (daemon *Daemon) HandlerJoin(client *Client, cmd string) {
 			continue
 		}
 		roomNew, roomSink := daemon.RoomRegister(room)
+		log.Println("Room", roomNew, "created")
 		if key != "" {
 			roomNew.key = key
 			roomNew.StateSave()
@@ -302,6 +322,7 @@ func (daemon *Daemon) Processor(events <-chan ClientEvent) {
 				log.Println(client, "command", command)
 			}
 			if command == "QUIT" {
+				log.Println(client, "quit")
 				delete(daemon.clients, client)
 				delete(daemon.clientAliveness, client)
 				client.conn.Close()
@@ -447,3 +468,22 @@ func (daemon *Daemon) Processor(events <-chan ClientEvent) {
 		}
 	}
 }
+
+func (daemon *Daemon) PasswordsRefresh() {
+	contents, err := ioutil.ReadFile(*passwords)
+	if err != nil {
+		log.Fatalf("Can no read passwords file %s: %s", *passwords, err)
+		return
+	}
+	processed := make(map[string]string)
+	for _, entry := range strings.Split(string(contents), "\n") {
+		loginAndPassword := strings.Split(entry, ":")
+		if len(loginAndPassword) == 2 {
+			processed[loginAndPassword[0]] = loginAndPassword[1]
+		}
+	}
+	log.Printf("Read %d passwords", len(processed))
+	passwordsRefreshLock.Lock()
+	daemon.passwords = processed
+	passwordsRefreshLock.Unlock()
+}

goircd.go

@@ -23,9 +23,12 @@ import (
 	"io/ioutil"
 	"log"
 	"net"
+	"os"
+	"os/signal"
 	"path"
 	"path/filepath"
 	"strings"
+	"syscall"
 )
 
 var (
@@ -34,6 +37,7 @@ var (
 	motd      = flag.String("motd", "", "Path to MOTD file")
 	logdir    = flag.String("logdir", "", "Absolute path to directory for logs")
 	statedir  = flag.String("statedir", "", "Absolute path to directory for states")
+	passwords = flag.String("passwords", "", "Optional path to passwords file")
 
 	tlsKey  = flag.String("tls_key", "", "TLS keyfile")
 	tlsCert = flag.String("tls_cert", "", "TLS certificate")
@@ -118,6 +122,18 @@ func Run() {
 	}
 	log.Println("Listening on", *bind)
 
+	if *passwords != "" {
+		daemon.PasswordsRefresh()
+		hups := make(chan os.Signal)
+		signal.Notify(hups, syscall.SIGHUP)
+		go func() {
+			for {
+				<-hups
+				daemon.PasswordsRefresh()
+			}
+		}()
+	}
+
 	go daemon.Processor(events)
 	for {
 		conn, err := listener.Accept()

room.go

@@ -46,6 +46,10 @@ type Room struct {
 	stateSink chan<- StateEvent
 }
 
+func (r Room) String() string {
+	return r.name
+}
+
 func NewRoom(hostname, name string, logSink chan<- LogEvent, stateSink chan<- StateEvent) *Room {
 	room := Room{name: name}
 	room.members = make(map[*Client]bool)