Better makefile and working chat.

Makefile

@@ -0,0 +1,22 @@
+BINARY = ssh-chat
+KEY = host_key
+PORT = 2022
+
+all: $(BINARY)
+
+**/*.go:
+	go build ./...
+
+$(BINARY): **/*.go *.go
+	go build .
+
+build: $(BINARY)
+
+clean:
+	rm $(BINARY)
+
+key: $(KEY)
+	ssh-keygen -f $(KEY) -P ''
+
+run: $(BINARY) $(KEY)
+	./$(BINARY) -i $(KEY) -b ":$(PORT)" -vv

client.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+const MSG_BUFFER = 10
+
+type Client struct {
+	Server *Server
+	Msg    chan string
+	Name   string
+}
+
+func NewClient(server *Server, name string) *Client {
+	if name == "" {
+		name = "Anonymoose"
+	}
+
+	return &Client{
+		Server: server,
+		Name:   name,
+		Msg:    make(chan string, MSG_BUFFER),
+	}
+}
+
+func (c *Client) handleShell(channel ssh.Channel) {
+	defer channel.Close()
+
+	term := terminal.NewTerminal(channel, "")
+
+	for {
+		line, err := term.ReadLine()
+		if err != nil {
+			break
+		}
+
+		switch line {
+		case "/exit":
+			channel.Close()
+		}
+
+		msg := fmt.Sprintf("%s: %s\r\n", c.Name, line)
+		c.Server.Broadcast(msg)
+	}
+}
+
+func (c *Client) handleChannels(channels <-chan ssh.NewChannel) {
+	for ch := range channels {
+		if t := ch.ChannelType(); t != "session" {
+			ch.Reject(ssh.UnknownChannelType, fmt.Sprintf("unknown channel type: %s", t))
+			continue
+		}
+
+		channel, requests, err := ch.Accept()
+		if err != nil {
+			logger.Errorf("Could not accept channel: %v", err)
+			continue
+		}
+
+		go func(in <-chan *ssh.Request) {
+			defer channel.Close()
+			for req := range in {
+				ok := false
+				switch req.Type {
+				case "shell":
+					if len(req.Payload) == 0 {
+						ok = true
+					}
+				case "pty-req":
+					// Setup PTY
+					ok = true
+				}
+				req.Reply(ok, nil)
+			}
+		}(requests)
+
+		go c.handleShell(channel)
+
+		go func() {
+			for msg := range c.Msg {
+				channel.Write([]byte(msg))
+			}
+		}()
+
+		// We don't care about other channels?
+		return
+	}
+}

cmd.go

@@ -59,17 +59,14 @@ func main() {
 	// Construct interrupt handler
 	sig := make(chan os.Signal, 1)
 	signal.Notify(sig, os.Interrupt)
-	go func() {
-		<-sig // Wait for ^C signal
-		logger.Warningf("Interrupt signal detected, shutting down.")
-		server.Stop()
-	}()
 
-	done, err := server.Start(options.Bind)
+	err = server.Start(options.Bind)
 	if err != nil {
 		logger.Errorf("Failed to start server: %v", err)
 		return
 	}
 
-	<-done
+	<-sig // Wait for ^C signal
+	logger.Warningf("Interrupt signal detected, shutting down.")
+	server.Stop()
 }

server.go

@@ -1,19 +1,20 @@
-// TODO: NoClientAuth
-
 package main
 
 import (
 	"fmt"
-	"golang.org/x/crypto/ssh"
-	"golang.org/x/crypto/ssh/terminal"
 	"net"
+	"strings"
+	"sync"
+
+	"golang.org/x/crypto/ssh"
 )
 
 type Server struct {
 	sshConfig *ssh.ServerConfig
 	sshSigner *ssh.Signer
-	socket    *net.Listener
 	done      chan struct{}
+	clients   []Client
+	lock      sync.Mutex
 }
 
 func NewServer(privateKey []byte) (*Server, error) {
@@ -23,120 +24,87 @@ func NewServer(privateKey []byte) (*Server, error) {
 	}
 
 	config := ssh.ServerConfig{
-		NoClientAuth: true,
+		NoClientAuth: false,
+		PasswordCallback: func(conn ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
+			return nil, nil
+		},
+		PublicKeyCallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
+			return nil, nil
+		},
 	}
 	config.AddHostKey(signer)
 
 	server := Server{
 		sshConfig: &config,
 		sshSigner: &signer,
+		done:      make(chan struct{}),
 	}
 
 	return &server, nil
 }
 
-func (s *Server) handleShell(channel ssh.Channel) {
-	defer channel.Close()
-
-	term := terminal.NewTerminal(channel, "")
-
-	for {
-		line, err := term.ReadLine()
-		if err != nil {
-			break
-		}
-
-		switch line {
-		case "exit":
-			channel.Close()
-		}
-
-		term.Write([]byte("you wrote: " + string(line) + "\r\n"))
+func (s *Server) Broadcast(msg string) {
+	logger.Debugf("Broadcast to %d: %s", len(s.clients), strings.TrimRight(msg, "\r\n"))
+	for _, client := range s.clients {
+		client.Msg <- msg
 	}
 }
 
-func (s *Server) handleChannels(channels <-chan ssh.NewChannel) {
-	for ch := range channels {
-		if t := ch.ChannelType(); t != "session" {
-			ch.Reject(ssh.UnknownChannelType, fmt.Sprintf("unknown channel type: %s", t))
-			continue
-		}
-
-		channel, requests, err := ch.Accept()
-		if err != nil {
-			logger.Errorf("Could not accept channel: %v", err)
-			continue
-		}
-
-		go func(in <-chan *ssh.Request) {
-			defer channel.Close()
-			for req := range in {
-				logger.Infof("Request: ", req.Type, string(req.Payload))
-
-				ok := false
-				switch req.Type {
-				case "shell":
-					// We don't accept any commands (Payload),
-					// only the default shell.
-					if len(req.Payload) == 0 {
-						ok = true
-					}
-				case "pty-req":
-					// Responding 'ok' here will let the client
-					// know we have a pty ready for input
-					ok = true
-				case "window-change":
-					continue //no response
-				}
-				req.Reply(ok, nil)
-			}
-		}(requests)
-
-		go s.handleShell(channel)
-
-		channel.Write([]byte("Hello"))
-	}
-}
-
-func (s *Server) Start(laddr string) (<-chan struct{}, error) {
+func (s *Server) Start(laddr string) error {
 	// Once a ServerConfig has been configured, connections can be
 	// accepted.
 	socket, err := net.Listen("tcp", laddr)
 	if err != nil {
-		return nil, err
+		return err
 	}
 
-	s.socket = &socket
 	logger.Infof("Listening on %s", laddr)
 
 	go func() {
 		for {
 			conn, err := socket.Accept()
+
 			if err != nil {
-				// TODO: Handle shutdown more gracefully.
+				// TODO: Handle shutdown more gracefully?
 				logger.Errorf("Failed to accept connection, aborting loop: %v", err)
 				return
 			}
 
-			// From a standard TCP connection to an encrypted SSH connection
-			sshConn, channels, requests, err := ssh.NewServerConn(conn, s.sshConfig)
-			if err != nil {
-				logger.Errorf("Failed to handshake: %v", err)
-				continue
-			}
+			// Goroutineify to resume accepting sockets early.
+			go func() {
+				// From a standard TCP connection to an encrypted SSH connection
+				sshConn, channels, requests, err := ssh.NewServerConn(conn, s.sshConfig)
+				if err != nil {
+					logger.Errorf("Failed to handshake: %v", err)
+					return
+				}
 
-			logger.Infof("Connection from: %s, %s, %s", sshConn.RemoteAddr(), sshConn.User(), sshConn.ClientVersion())
+				logger.Infof("Connection from: %s, %s, %s", sshConn.RemoteAddr(), sshConn.User(), sshConn.ClientVersion())
 
-			go ssh.DiscardRequests(requests)
-			go s.handleChannels(channels)
+				go ssh.DiscardRequests(requests)
+
+				client := NewClient(s, sshConn.User())
+				// TODO: mutex this
+
+				s.lock.Lock()
+				s.clients = append(s.clients, *client)
+				s.lock.Unlock()
+
+				s.Broadcast(fmt.Sprintf("* Joined: %s", client.Name))
+
+				go client.handleChannels(channels)
+			}()
 		}
 	}()
 
-	return s.done, nil
+	go func() {
+		<-s.done
+		socket.Close()
+	}()
+
+	return nil
 }
 
-func (s *Server) Stop() error {
-	err := (*s.socket).Close()
-	s.done <- struct{}{}
-	return err
+func (s *Server) Stop() {
+	close(s.done)
 }