Merge pull request #439 from jagtalon/jag/readme

README: Change whitelist to allowlist

.github/ISSUE_TEMPLATE/BUG.yml

@@ -0,0 +1,63 @@
+name: Bug Report
+description: Create a report to fix something that is broken
+title: "[Bug]: "
+labels: ["bug", "needs-triage"]
+body:
+  - type: textarea
+    id: summary
+    validations:
+      required: true
+    attributes:
+      label: Summary
+      description: A clear and concise description of what the bug is.
+  - type: input
+    id: client-version
+    attributes:
+      label: Client version
+      description: Paste output of `ssh -V`
+    validations:
+      required: true
+  - type: input
+    id: server-version
+    attributes:
+      label: Server version
+      description: Paste output of `ssh-chat --version`
+      placeholder: e.g., ssh-chat v0.1.0
+    validations:
+      required: true
+
+  - type: input
+    id: latest-server-version
+    attributes:
+      label: Latest server version available (at time of report)
+      description: Check https://github.com/shazow/ssh-chat/releases and paste the latest version
+      placeholder: e.g., v0.2.0
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproduce
+    attributes:
+      label: To Reproduce
+      description: Steps to reproduce the behavior
+      placeholder: |
+        1. Full command to run...
+        2. Resulting output...
+      render: markdown
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+      description: A clear and concise description of what you expected to happen.
+      placeholder: Describe the expected behavior
+    validations:
+      required: true
+
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional context
+      description: Add any other context about the problem here.

.github/workflows/go.yml

@@ -29,4 +29,4 @@ jobs:
       run: go build -v .
 
     - name: Test
-      run: go test -race -vet "all" -v .
+      run: go test -race -vet "all" -v ./...

Dockerfile

@@ -0,0 +1,21 @@
+FROM golang:alpine AS builder
+
+WORKDIR /usr/src/app
+
+COPY . .
+RUN apk add make openssh
+RUN make build
+
+
+FROM alpine
+
+RUN apk add openssh
+RUN mkdir /root/.ssh
+WORKDIR /root/.ssh
+RUN ssh-keygen -t rsa -C "chatkey" -f id_rsa
+
+WORKDIR /usr/local/bin
+
+COPY --from=builder /usr/src/app/ssh-chat .
+RUN chmod +x ssh-chat
+CMD ["/usr/local/bin/ssh-chat"]

Makefile

@@ -35,6 +35,13 @@ release:
 	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
 	CGO_ENABLED=0 GOOS=linux GOARCH=386 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=6 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
+	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
 	CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
+	CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
 	CGO_ENABLED=0 GOOS=freebsd GOARCH=amd64 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
 	CGO_ENABLED=0 GOOS=windows GOARCH=386 LDFLAGS='$(LDFLAGS)' ./build_release "github.com/shazow/ssh-chat/cmd/ssh-chat" README.md LICENSE
+
+deploy: build/ssh-chat-linux_amd64.tgz
+	ssh -p 2022 ssh.chat tar xvz < build/ssh-chat-linux_amd64.tgz
+	@echo " --- Ready to deploy ---"
+	@echo "Run: ssh -t -p 2022 ssh.chat sudo systemctl restart ssh-chat"

README.md

@@ -12,13 +12,15 @@ Custom SSH server written in Go. Instead of a shell, you get a chat prompt.
 
 Join the party:
 
-```
+``` console
 $ ssh ssh.chat
 ```
 
 Please abide by our [project's Code of Conduct](https://github.com/shazow/ssh-chat/blob/master/CODE_OF_CONDUCT.md) while participating in chat.
 
-The server's RSA key fingerprint is `MD5:e5:d5:d1:75:90:38:42:f6:c7:03:d7:d0:56:7d:6a:db` or `SHA256:HQDLlZsXL3t0lV5CHM0OXeZ5O6PcfHuzkS8cRbbTLBI`. If you see something different, you might be [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)'d.
+The host's public key is `ssh.chat ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKPrQofxXqoz2y9A7NFkkENt6iW8/mvpfes3RY/41Oyt` and the fingerprint is `SHA256:yoqMXkCysMTBsvhu2yRoMUl+EmZKlvkN+ZKmL3115xU` (as of 2021-10-13).
+
+If you see something different, you might be [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)'d.
 
 (Apologies if the server is down, try again shortly.)
 
@@ -50,7 +52,7 @@ Additionally, `make debug` runs the server with an http `pprof` server. This all
 
 ## Quick Start
 
-```
+``` console
 Usage:
   ssh-chat [OPTIONS]
 
@@ -60,7 +62,7 @@ Application Options:
   -i, --identity=  Private key to identify server with. (default: ~/.ssh/id_rsa)
       --bind=      Host and port to listen on. (default: 0.0.0.0:2022)
       --admin=     File of public keys who are admins.
-      --whitelist= Optional file of public keys who are allowed to connect.
+      --allowlist= Optional file of public keys who are allowed to connect.
       --motd=      Optional Message of the Day file.
       --log=       Write chat log to this file.
       --pprof=     Enable pprof http server for profiling.
@@ -72,7 +74,7 @@ Help Options:
 After doing `go get github.com/shazow/ssh-chat/...` on this repo, you should be able
 to run a command like:
 
-```
+``` console
 $ ssh-chat --verbose --bind ":22" --identity ~/.ssh/id_dsa
 ```
 

auth.go

@@ -1,11 +1,14 @@
 package sshchat
 
 import (
+	"crypto/sha256"
+	"crypto/subtle"
 	"encoding/csv"
 	"errors"
 	"fmt"
 	"net"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/shazow/ssh-chat/set"
@@ -13,13 +16,20 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-// ErrNotWhitelisted Is the error returned when a key is checked that is not whitelisted,
-// when whitelisting is enabled.
-var ErrNotWhitelisted = errors.New("not whitelisted")
+// KeyLoader loads public keys, e.g. from an authorized_keys file.
+// It must return a nil slice on error.
+type KeyLoader func() ([]ssh.PublicKey, error)
 
-// ErrBanned is the error returned when a key is checked that is banned.
+// ErrNotAllowed Is the error returned when a key is checked that is not allowlisted,
+// when allowlisting is enabled.
+var ErrNotAllowed = errors.New("not allowed")
+
+// ErrBanned is the error returned when a client is banned.
 var ErrBanned = errors.New("banned")
 
+// ErrIncorrectPassphrase is the error returned when a provided passphrase is incorrect.
+var ErrIncorrectPassphrase = errors.New("incorrect passphrase")
+
 // newAuthKey returns string from an ssh.PublicKey used to index the key in our lookup.
 func newAuthKey(key ssh.PublicKey) string {
 	if key == nil {
@@ -42,13 +52,20 @@ func newAuthAddr(addr net.Addr) string {
 	return host
 }
 
-// Auth stores lookups for bans, whitelists, and ops. It implements the sshd.Auth interface.
+// Auth stores lookups for bans, allowlists, and ops. It implements the sshd.Auth interface.
+// If the contained passphrase is not empty, it complements a allowlist.
 type Auth struct {
-	bannedAddr   *set.Set
-	bannedClient *set.Set
-	banned       *set.Set
-	whitelist    *set.Set
-	ops          *set.Set
+	passphraseHash []byte
+	bannedAddr     *set.Set
+	bannedClient   *set.Set
+	banned         *set.Set
+	allowlist      *set.Set
+	ops            *set.Set
+
+	settingsMu      sync.RWMutex
+	allowlistMode   bool
+	opLoader        KeyLoader
+	allowlistLoader KeyLoader
 }
 
 // NewAuth creates a new empty Auth.
@@ -57,28 +74,47 @@ func NewAuth() *Auth {
 		bannedAddr:   set.New(),
 		bannedClient: set.New(),
 		banned:       set.New(),
-		whitelist:    set.New(),
+		allowlist:    set.New(),
 		ops:          set.New(),
 	}
 }
 
+func (a *Auth) AllowlistMode() bool {
+	a.settingsMu.RLock()
+	defer a.settingsMu.RUnlock()
+	return a.allowlistMode
+}
+
+func (a *Auth) SetAllowlistMode(value bool) {
+	a.settingsMu.Lock()
+	defer a.settingsMu.Unlock()
+	a.allowlistMode = value
+}
+
+// SetPassphrase enables passphrase authentication with the given passphrase.
+// If an empty passphrase is given, disable passphrase authentication.
+func (a *Auth) SetPassphrase(passphrase string) {
+	if passphrase == "" {
+		a.passphraseHash = nil
+	} else {
+		hashArray := sha256.Sum256([]byte(passphrase))
+		a.passphraseHash = hashArray[:]
+	}
+}
+
 // AllowAnonymous determines if anonymous users are permitted.
 func (a *Auth) AllowAnonymous() bool {
-	return a.whitelist.Len() == 0
+	return !a.AllowlistMode() && a.passphraseHash == nil
 }
 
-// Check determines if a pubkey fingerprint is permitted.
-func (a *Auth) Check(addr net.Addr, key ssh.PublicKey, clientVersion string) error {
-	authkey := newAuthKey(key)
+// AcceptPassphrase determines if passphrase authentication is accepted.
+func (a *Auth) AcceptPassphrase() bool {
+	return a.passphraseHash != nil
+}
 
-	if a.whitelist.Len() != 0 {
-		// Only check whitelist if there is something in it, otherwise it's disabled.
-		whitelisted := a.whitelist.In(authkey)
-		if !whitelisted {
-			return ErrNotWhitelisted
-		}
-		return nil
-	}
+// CheckBans checks IP, key and client bans.
+func (a *Auth) CheckBans(addr net.Addr, key ssh.PublicKey, clientVersion string) error {
+	authkey := newAuthKey(key)
 
 	var banned bool
 	if authkey != "" {
@@ -98,6 +134,29 @@ func (a *Auth) Check(addr net.Addr, key ssh.PublicKey, clientVersion string) err
 	return nil
 }
 
+// CheckPubkey determines if a pubkey fingerprint is permitted.
+func (a *Auth) CheckPublicKey(key ssh.PublicKey) error {
+	authkey := newAuthKey(key)
+	allowlisted := a.allowlist.In(authkey)
+	if a.AllowAnonymous() || allowlisted || a.IsOp(key) {
+		return nil
+	} else {
+		return ErrNotAllowed
+	}
+}
+
+// CheckPassphrase determines if a passphrase is permitted.
+func (a *Auth) CheckPassphrase(passphrase string) error {
+	if !a.AcceptPassphrase() {
+		return errors.New("passphrases not accepted") // this should never happen
+	}
+	passedPassphraseHash := sha256.Sum256([]byte(passphrase))
+	if subtle.ConstantTimeCompare(passedPassphraseHash[:], a.passphraseHash) == 0 {
+		return ErrIncorrectPassphrase
+	}
+	return nil
+}
+
 // Op sets a public key as a known operator.
 func (a *Auth) Op(key ssh.PublicKey, d time.Duration) {
 	if key == nil {
@@ -114,25 +173,68 @@ func (a *Auth) Op(key ssh.PublicKey, d time.Duration) {
 
 // IsOp checks if a public key is an op.
 func (a *Auth) IsOp(key ssh.PublicKey) bool {
-	if key == nil {
-		return false
-	}
 	authkey := newAuthKey(key)
 	return a.ops.In(authkey)
 }
 
-// Whitelist will set a public key as a whitelisted user.
-func (a *Auth) Whitelist(key ssh.PublicKey, d time.Duration) {
+// LoadOps sets the public keys form loader to operators and saves the loader for later use
+func (a *Auth) LoadOps(loader KeyLoader) error {
+	a.settingsMu.Lock()
+	a.opLoader = loader
+	a.settingsMu.Unlock()
+	return a.ReloadOps()
+}
+
+// ReloadOps sets the public keys from a loader saved in the last call to operators
+func (a *Auth) ReloadOps() error {
+	a.settingsMu.RLock()
+	defer a.settingsMu.RUnlock()
+	return addFromLoader(a.opLoader, a.Op)
+}
+
+// Allowlist will set a public key as a allowlisted user.
+func (a *Auth) Allowlist(key ssh.PublicKey, d time.Duration) {
 	if key == nil {
 		return
 	}
+	var err error
 	authItem := newAuthItem(key)
 	if d != 0 {
-		a.whitelist.Set(set.Expire(authItem, d))
+		err = a.allowlist.Set(set.Expire(authItem, d))
 	} else {
-		a.whitelist.Set(authItem)
+		err = a.allowlist.Set(authItem)
 	}
-	logger.Debugf("Added to whitelist: %q (for %s)", authItem.Key(), d)
+	if err == nil {
+		logger.Debugf("Added to allowlist: %q (for %s)", authItem.Key(), d)
+	} else {
+		logger.Errorf("Error adding %q to allowlist for %s: %s", authItem.Key(), d, err)
+	}
+}
+
+// LoadAllowlist adds the public keys from the loader to the allowlist and saves the loader for later use
+func (a *Auth) LoadAllowlist(loader KeyLoader) error {
+	a.settingsMu.Lock()
+	a.allowlistLoader = loader
+	a.settingsMu.Unlock()
+	return a.ReloadAllowlist()
+}
+
+//  LoadAllowlist adds the public keys from a loader saved in a previous call to the allowlist
+func (a *Auth) ReloadAllowlist() error {
+	a.settingsMu.RLock()
+	defer a.settingsMu.RUnlock()
+	return addFromLoader(a.allowlistLoader, a.Allowlist)
+}
+
+func addFromLoader(loader KeyLoader, adder func(ssh.PublicKey, time.Duration)) error {
+	if loader == nil {
+		return nil
+	}
+	keys, err := loader()
+	for _, key := range keys {
+		adder(key, 0)
+	}
+	return err
 }
 
 // Ban will set a public key as banned.

auth_test.go

@@ -21,19 +21,20 @@ func ClonePublicKey(key ssh.PublicKey) (ssh.PublicKey, error) {
 	return ssh.ParsePublicKey(key.Marshal())
 }
 
-func TestAuthWhitelist(t *testing.T) {
+func TestAuthAllowlist(t *testing.T) {
 	key, err := NewRandomPublicKey(512)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	auth := NewAuth()
-	err = auth.Check(nil, key, "")
+	err = auth.CheckPublicKey(key)
 	if err != nil {
 		t.Error("Failed to permit in default state:", err)
 	}
 
-	auth.Whitelist(key, 0)
+	auth.Allowlist(key, 0)
+	auth.SetAllowlistMode(true)
 
 	keyClone, err := ClonePublicKey(key)
 	if err != nil {
@@ -44,9 +45,9 @@ func TestAuthWhitelist(t *testing.T) {
 		t.Error("Clone key does not match.")
 	}
 
-	err = auth.Check(nil, keyClone, "")
+	err = auth.CheckPublicKey(keyClone)
 	if err != nil {
-		t.Error("Failed to permit whitelisted:", err)
+		t.Error("Failed to permit allowlisted:", err)
 	}
 
 	key2, err := NewRandomPublicKey(512)
@@ -54,8 +55,42 @@ func TestAuthWhitelist(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = auth.Check(nil, key2, "")
+	err = auth.CheckPublicKey(key2)
 	if err == nil {
-		t.Error("Failed to restrict not whitelisted:", err)
+		t.Error("Failed to restrict not allowlisted:", err)
+	}
+}
+
+func TestAuthPassphrases(t *testing.T) {
+	auth := NewAuth()
+
+	if auth.AcceptPassphrase() {
+		t.Error("Doesn't known it won't accept passphrases.")
+	}
+	auth.SetPassphrase("")
+	if auth.AcceptPassphrase() {
+		t.Error("Doesn't known it won't accept passphrases.")
+	}
+
+	err := auth.CheckPassphrase("Pa$$w0rd")
+	if err == nil {
+		t.Error("Failed to deny without passphrase:", err)
+	}
+
+	auth.SetPassphrase("Pa$$w0rd")
+
+	err = auth.CheckPassphrase("Pa$$w0rd")
+	if err != nil {
+		t.Error("Failed to allow vaild passphrase:", err)
+	}
+
+	err = auth.CheckPassphrase("something else")
+	if err == nil {
+		t.Error("Failed to restrict wrong passphrase:", err)
+	}
+
+	auth.SetPassphrase("")
+	if auth.AcceptPassphrase() {
+		t.Error("Didn't clear passphrase.")
 	}
 }

chat/command.go

@@ -458,4 +458,72 @@ func InitCommands(c *Commands) {
 			return nil
 		},
 	})
+
+	c.Add(Command{
+		Prefix:     "/away",
+		PrefixHelp: "[REASON]",
+		Help:       "Set away reason, or empty to unset.",
+		Handler: func(room *Room, msg message.CommandMsg) error {
+			awayMsg := strings.TrimSpace(strings.TrimLeft(msg.Body(), "/away"))
+			isAway, _, _ := msg.From().GetAway()
+			msg.From().SetAway(awayMsg)
+			if awayMsg != "" {
+				room.Send(message.NewEmoteMsg("has gone away: "+awayMsg, msg.From()))
+				return nil
+			}
+			if isAway {
+				room.Send(message.NewEmoteMsg("is back.", msg.From()))
+				return nil
+			}
+			return errors.New("not away. Append a reason message to set away")
+		},
+	})
+
+	c.Add(Command{
+		Prefix: "/back",
+		Help:   "Clear away status.",
+		Handler: func(room *Room, msg message.CommandMsg) error {
+			isAway, _, _ := msg.From().GetAway()
+			if isAway {
+				msg.From().SetAway("")
+				room.Send(message.NewEmoteMsg("is back.", msg.From()))
+				return nil
+			}
+			return errors.New("must be away to be back")
+		},
+	})
+
+	c.Add(Command{
+		Op:         true,
+		Prefix:     "/mute",
+		PrefixHelp: "USER",
+		Help:       "Toggle muting USER, preventing messages from broadcasting.",
+		Handler: func(room *Room, msg message.CommandMsg) error {
+			if !room.IsOp(msg.From()) {
+				return errors.New("must be op")
+			}
+
+			args := msg.Args()
+			if len(args) == 0 {
+				return errors.New("must specify user")
+			}
+
+			member, ok := room.MemberByID(args[0])
+			if !ok {
+				return errors.New("user not found")
+			}
+
+			setMute := !member.IsMuted()
+			member.SetMute(setMute)
+			id := member.ID()
+
+			if setMute {
+				room.Send(message.NewSystemMsg("Muted: "+id, msg.From()))
+			} else {
+				room.Send(message.NewSystemMsg("Unmuted: "+id, msg.From()))
+			}
+
+			return nil
+		},
+	})
 }

chat/command_test.go

@@ -0,0 +1,70 @@
+package chat
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/shazow/ssh-chat/chat/message"
+)
+
+func TestAwayCommands(t *testing.T) {
+	cmds := &Commands{}
+	InitCommands(cmds)
+
+	room := NewRoom()
+	go room.Serve()
+	defer room.Close()
+
+	// steps are order dependent
+	// User can be "away" or "not away" using 3 commands "/away [msg]", "/away", "/back"
+	// 2^3 possible cases, run all and verify state at the end
+	type step struct {
+		// input
+		Msg string
+
+		// expected output
+		IsUserAway  bool
+		AwayMessage string
+
+		// expected state change
+		ExpectsError func(awayBefore bool) bool
+	}
+	neverError := func(_ bool) bool { return false }
+	// if the user was away before, then the error is expected
+	errorIfAwayBefore := func(awayBefore bool) bool { return awayBefore }
+
+	awayStep := step{"/away snorkling", true, "snorkling", neverError}
+	notAwayStep := step{"/away", false, "", errorIfAwayBefore}
+	backStep := step{"/back", false, "", errorIfAwayBefore}
+
+	steps := []step{awayStep, notAwayStep, backStep}
+	cases := [][]int{
+		{0, 1, 2}, {0, 2, 1}, {1, 0, 2}, {1, 2, 0}, {2, 0, 1}, {2, 1, 0},
+	}
+	for _, c := range cases {
+		t.Run(fmt.Sprintf("Case: %d, %d, %d", c[0], c[1], c[2]), func(t *testing.T) {
+
+			u := message.NewUser(message.SimpleID("shark"))
+
+			for _, s := range []step{steps[c[0]], steps[c[1]], steps[c[2]]} {
+				msg, _ := message.NewPublicMsg(s.Msg, u).ParseCommand()
+
+				awayBeforeCommand, _, _ := u.GetAway()
+
+				err := cmds.Run(room, *msg)
+				if err != nil && s.ExpectsError(awayBeforeCommand) {
+					t.Fatalf("unexpected error running the command: %+v", err)
+				}
+
+				isAway, _, awayMsg := u.GetAway()
+				if isAway != s.IsUserAway {
+					t.Fatalf("expected user away state '%t' not equals to actual '%t' after message '%s'", s.IsUserAway, isAway, s.Msg)
+				}
+				if awayMsg != s.AwayMessage {
+					t.Fatalf("expected user away message '%s' not equal to actual '%s' after message '%s'", s.AwayMessage, awayMsg, s.Msg)
+				}
+			}
+
+		})
+	}
+}

chat/logger.go

@@ -1,7 +1,9 @@
 package chat
 
-import "io"
-import stdlog "log"
+import (
+	"io"
+	stdlog "log"
+)
 
 var logger *stdlog.Logger
 

chat/message/message.go

@@ -191,10 +191,11 @@ func (m PrivateMsg) From() *User {
 }
 
 func (m PrivateMsg) Render(t *Theme) string {
-	s := fmt.Sprintf("[PM from %s] %s", m.from.Name(), m.body)
+	format := "[PM from %s] %s"
 	if t == nil {
-		return s
+		return fmt.Sprintf(format, m.from.ID(), m.body) 
 	}
+	s := fmt.Sprintf(format, m.from.Name(), m.body)
 	return t.ColorPM(s)
 }
 

chat/message/user.go

@@ -33,10 +33,12 @@ type User struct {
 	screen    io.WriteCloser
 	closeOnce sync.Once
 
-	mu      sync.Mutex
-	config  UserConfig
-	replyTo *User     // Set when user gets a /msg, for replying.
-	lastMsg time.Time // When the last message was rendered
+	mu         sync.Mutex
+	config     UserConfig
+	replyTo    *User     // Set when user gets a /msg, for replying.
+	lastMsg    time.Time // When the last message was rendered.
+	awayReason string    // Away reason, "" when not away.
+	awaySince  time.Time // When away was set, 0 when not away.
 }
 
 func NewUser(identity Identifier) *User {
@@ -71,6 +73,26 @@ func (u *User) LastMsg() time.Time {
 	return u.lastMsg
 }
 
+// SetAway sets the users away reason and state.
+func (u *User) SetAway(msg string) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	u.awayReason = msg
+	if msg == "" {
+		u.awaySince = time.Time{}
+	} else {
+		// Reset away timer even if already away
+		u.awaySince = time.Now()
+	}
+}
+
+// GetAway returns if the user is away, when they went away, and the reason.
+func (u *User) GetAway() (bool, time.Time, string) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	return u.awayReason != "", u.awaySince, u.awayReason
+}
+
 func (u *User) Config() UserConfig {
 	u.mu.Lock()
 	defer u.mu.Unlock()
@@ -121,7 +143,9 @@ func (u *User) setColorIdx(idx int) {
 func (u *User) Close() {
 	u.closeOnce.Do(func() {
 		if u.screen != nil {
-			u.screen.Close()
+			if err := u.screen.Close(); err != nil {
+				logger.Printf("Failed to close user %q screen: %s", u.ID(), err)
+			}
 		}
 		// close(u.msg) TODO: Close?
 		close(u.done)

chat/room.go

@@ -27,6 +27,23 @@ var ErrInvalidName = errors.New("invalid name")
 type Member struct {
 	*message.User
 	IsOp bool
+
+	// TODO: Move IsOp under mu?
+
+	mu      sync.Mutex
+	isMuted bool // When true, messages should not be broadcasted.
+}
+
+func (m *Member) IsMuted() bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.isMuted
+}
+
+func (m *Member) SetMute(muted bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.isMuted = muted
 }
 
 // Room definition, also a Set of User Items
@@ -84,6 +101,20 @@ func (r *Room) HandleMsg(m message.Message) {
 		fromID = fromMsg.From().ID()
 	}
 
+	if fromID != "" {
+		if item, err := r.Members.Get(fromID); err != nil {
+			// Message from a member who is not in the room, this should not happen.
+			logger.Printf("Room received unexpected message from a non-member: %v", m)
+			return
+		} else if member, ok := item.Value().(*Member); ok && member.IsMuted() {
+			// Short circuit message handling for muted users
+			if _, ok = m.(*message.CommandMsg); !ok {
+				member.User.Send(m)
+			}
+			return
+		}
+	}
+
 	switch m := m.(type) {
 	case *message.CommandMsg:
 		cmd := *m
@@ -150,6 +181,7 @@ func (r *Room) Join(u *message.User) (*Member, error) {
 	if err != nil {
 		return nil, err
 	}
+	// TODO: Remove user ID from sets, probably referring to a prior user.
 	r.History(u)
 	s := fmt.Sprintf("%s joined. (Connected: %d)", u.Name(), r.Members.Len())
 	r.Send(message.NewAnnounceMsg(s))

chat/room_test.go

@@ -158,6 +158,94 @@ func TestIgnore(t *testing.T) {
 	expectOutput(t, buffer, ignored.user.Name()+": hello again!"+message.Newline)
 }
 
+func TestMute(t *testing.T) {
+	var buffer []byte
+
+	ch := NewRoom()
+	go ch.Serve()
+	defer ch.Close()
+
+	// Create 3 users, join the room and clear their screen buffers
+	users := make([]ScreenedUser, 3)
+	members := make([]*Member, 3)
+	for i := 0; i < 3; i++ {
+		screen := &MockScreen{}
+		user := message.NewUserScreen(message.SimpleID(fmt.Sprintf("user%d", i)), screen)
+		users[i] = ScreenedUser{
+			user:   user,
+			screen: screen,
+		}
+
+		member, err := ch.Join(user)
+		if err != nil {
+			t.Fatal(err)
+		}
+		members[i] = member
+	}
+
+	for _, u := range users {
+		for i := 0; i < 3; i++ {
+			u.user.HandleMsg(u.user.ConsumeOne())
+			u.screen.Read(&buffer)
+		}
+	}
+
+	// Use some handy variable names for distinguish between roles
+	muter := users[0]
+	muted := users[1]
+	other := users[2]
+
+	members[0].IsOp = true
+
+	// test muting unexisting user
+	if err := sendCommand("/mute test", muter, ch, &buffer); err != nil {
+		t.Fatal(err)
+	}
+	expectOutput(t, buffer, "-> Err: user not found"+message.Newline)
+
+	// test muting by non-op
+	if err := sendCommand("/mute "+muted.user.Name(), other, ch, &buffer); err != nil {
+		t.Fatal(err)
+	}
+	expectOutput(t, buffer, "-> Err: must be op"+message.Newline)
+
+	// test muting existing user
+	if err := sendCommand("/mute "+muted.user.Name(), muter, ch, &buffer); err != nil {
+		t.Fatal(err)
+	}
+	expectOutput(t, buffer, "-> Muted: "+muted.user.Name()+message.Newline)
+
+	if got, want := members[1].IsMuted(), true; got != want {
+		t.Error("muted user failed to set mute flag")
+	}
+
+	// when an emote is sent by a muted user, it should not be displayed for anyone
+	ch.HandleMsg(message.NewPublicMsg("hello!", muted.user))
+	ch.HandleMsg(message.NewEmoteMsg("is crying", muted.user))
+
+	if muter.user.HasMessages() {
+		muter.user.HandleMsg(muter.user.ConsumeOne())
+		muter.screen.Read(&buffer)
+		t.Errorf("muter should not have messages: %s", buffer)
+	}
+	if other.user.HasMessages() {
+		other.user.HandleMsg(other.user.ConsumeOne())
+		other.screen.Read(&buffer)
+		t.Errorf("other should not have messages: %s", buffer)
+	}
+
+	// test unmuting
+	if err := sendCommand("/mute "+muted.user.Name(), muter, ch, &buffer); err != nil {
+		t.Fatal(err)
+	}
+	expectOutput(t, buffer, "-> Unmuted: "+muted.user.Name()+message.Newline)
+
+	ch.HandleMsg(message.NewPublicMsg("hello again!", muted.user))
+	other.user.HandleMsg(other.user.ConsumeOne())
+	other.screen.Read(&buffer)
+	expectOutput(t, buffer, muted.user.Name()+": hello again!"+message.Newline)
+}
+
 func expectOutput(t *testing.T, buffer []byte, expected string) {
 	t.Helper()
 

cmd/ssh-chat/cmd.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -10,7 +9,6 @@ import (
 	"os/signal"
 	"os/user"
 	"strings"
-	"time"
 
 	"github.com/alexcesaro/log"
 	"github.com/alexcesaro/log/golog"
@@ -30,16 +28,17 @@ var Version string = "dev"
 
 // Options contains the flag options
 type Options struct {
-	Admin      string `long:"admin" description:"File of public keys who are admins."`
-	Bind       string `long:"bind" description:"Host and port to listen on." default:"0.0.0.0:2022"`
-	Identity   string `short:"i" long:"identity" description:"Private key to identify server with." default:"~/.ssh/id_rsa"`
-	Log        string `long:"log" description:"Write chat log to this file."`
-	Motd       string `long:"motd" description:"Optional Message of the Day file."`
-	Pprof      int    `long:"pprof" description:"Enable pprof http server for profiling."`
-	Verbose    []bool `short:"v" long:"verbose" description:"Show verbose logging."`
-	Version    bool   `long:"version" description:"Print version and exit."`
-	Whitelist  string `long:"whitelist" description:"Optional file of public keys who are allowed to connect."`
-	Passphrase string `long:"unsafe-passphrase" description:"Require an interactive passphrase to connect. Whitelist feature is more secure."`
+	Admin      string   `long:"admin" description:"File of public keys who are admins."`
+	Bind       string   `long:"bind" description:"Host and port to listen on." default:"0.0.0.0:2022"`
+	Identity   []string `short:"i" long:"identity" description:"Private key to identify server with." default:"~/.ssh/id_rsa"`
+	Log        string   `long:"log" description:"Write chat log to this file."`
+	Motd       string   `long:"motd" description:"Optional Message of the Day file."`
+	Pprof      int      `long:"pprof" description:"Enable pprof http server for profiling."`
+	Verbose    []bool   `short:"v" long:"verbose" description:"Show verbose logging."`
+	Version    bool     `long:"version" description:"Print version and exit."`
+	Allowlist  string   `long:"allowlist" description:"Optional file of public keys who are allowed to connect."`
+	Whitelist  string   `long:"whitelist" dexcription:"Old name for allowlist option"`
+	Passphrase string   `long:"unsafe-passphrase" description:"Require an interactive passphrase to connect. Allowlist feature is more secure."`
 }
 
 const extraHelp = `There are hidden options and easter eggs in ssh-chat. The source code is a good
@@ -89,7 +88,7 @@ func main() {
 
 	// Figure out the log level
 	numVerbose := len(options.Verbose)
-	if numVerbose > len(logLevels) {
+	if numVerbose >= len(logLevels) {
 		numVerbose = len(logLevels) - 1
 	}
 
@@ -104,61 +103,26 @@ func main() {
 		message.SetLogger(os.Stderr)
 	}
 
-	privateKeyPath := options.Identity
-	if strings.HasPrefix(privateKeyPath, "~/") {
-		user, err := user.Current()
-		if err == nil {
-			privateKeyPath = strings.Replace(privateKeyPath, "~", user.HomeDir, 1)
-		}
-	}
-
-	signer, err := ReadPrivateKey(privateKeyPath)
-	if err != nil {
-		fail(3, "Failed to read identity private key: %v\n", err)
-	}
-
 	auth := sshchat.NewAuth()
 	config := sshd.MakeAuth(auth)
-	config.AddHostKey(signer)
 	config.ServerVersion = "SSH-2.0-Go ssh-chat"
 	// FIXME: Should we be using config.NoClientAuth = true by default?
 
-	if options.Passphrase != "" {
-		if options.Whitelist != "" {
-			logger.Warning("Passphrase is disabled while whitelist is enabled.")
-		}
-		if config.KeyboardInteractiveCallback != nil {
-			fail(1, "Passphrase authentication conflicts with existing KeyboardInteractive setup.") // This should not happen
-		}
-
-		// We use KeyboardInteractiveCallback instead of PasswordCallback to
-		// avoid preventing the client from including a pubkey in the user
-		// identification.
-		config.KeyboardInteractiveCallback = func(conn ssh.ConnMetadata, challenge ssh.KeyboardInteractiveChallenge) (*ssh.Permissions, error) {
-			answers, err := challenge("", "", []string{"Passphrase required to connect: "}, []bool{true})
-			if err != nil {
-				return nil, err
-			}
-			if len(answers) == 1 && answers[0] == options.Passphrase {
-				// Success
-				return nil, nil
-			}
-			// It's not gonna do much but may as well throttle brute force attempts a little
-			time.Sleep(2 * time.Second)
-
-			return nil, errors.New("incorrect passphrase")
-		}
-
-		// We also need to override the PublicKeyCallback to prevent rando pubkeys from bypassing
-		cb := config.PublicKeyCallback
-		config.PublicKeyCallback = func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
-			perms, err := cb(conn, key)
+	for _, privateKeyPath := range options.Identity {
+		if strings.HasPrefix(privateKeyPath, "~/") {
+			user, err := user.Current()
 			if err == nil {
-				err = errors.New("passphrase authentication required")
+				privateKeyPath = strings.Replace(privateKeyPath, "~", user.HomeDir, 1)
 			}
-			return perms, err
 		}
 
+		signer, err := ReadPrivateKey(privateKeyPath)
+		if err != nil {
+			fail(3, "Failed to read identity private key: %v\n", err)
+		}
+
+		config.AddHostKey(signer)
+		fmt.Printf("Added server identity: %s\n", sshd.Fingerprint(signer.PublicKey()))
 	}
 
 	s, err := sshd.ListenSSH(options.Bind, config)
@@ -174,35 +138,24 @@ func main() {
 	host.SetTheme(message.Themes[0])
 	host.Version = Version
 
-	err = fromFile(options.Admin, func(line []byte) error {
-		key, _, _, _, err := ssh.ParseAuthorizedKey(line)
-		if err != nil {
-			if err.Error() == "ssh: no key found" {
-				return nil // Skip line
-			}
-			return err
-		}
-		auth.Op(key, 0)
-		return nil
-	})
+	if options.Passphrase != "" {
+		auth.SetPassphrase(options.Passphrase)
+	}
+
+	err = auth.LoadOps(loaderFromFile(options.Admin, logger))
 	if err != nil {
 		fail(5, "Failed to load admins: %v\n", err)
 	}
 
-	err = fromFile(options.Whitelist, func(line []byte) error {
-		key, _, _, _, err := ssh.ParseAuthorizedKey(line)
-		if err != nil {
-			if err.Error() == "ssh: no key found" {
-				return nil // Skip line
-			}
-			return err
-		}
-		auth.Whitelist(key, 0)
-		return nil
-	})
-	if err != nil {
-		fail(6, "Failed to load whitelist: %v\n", err)
+	if options.Allowlist == "" && options.Whitelist != "" {
+		fmt.Println("--whitelist was renamed to --allowlist.")
+		options.Allowlist = options.Whitelist
 	}
+	err = auth.LoadAllowlist(loaderFromFile(options.Allowlist, logger))
+	if err != nil {
+		fail(6, "Failed to load allowlist: %v\n", err)
+	}
+	auth.SetAllowlistMode(options.Allowlist != "")
 
 	if options.Motd != "" {
 		host.GetMOTD = func() (string, error) {
@@ -243,24 +196,32 @@ func main() {
 	fmt.Fprintln(os.Stderr, "Interrupt signal detected, shutting down.")
 }
 
-func fromFile(path string, handler func(line []byte) error) error {
+func loaderFromFile(path string, logger *golog.Logger) sshchat.KeyLoader {
 	if path == "" {
-		// Skip
 		return nil
 	}
-
-	file, err := os.Open(path)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-
-	scanner := bufio.NewScanner(file)
-	for scanner.Scan() {
-		err := handler(scanner.Bytes())
+	return func() ([]ssh.PublicKey, error) {
+		file, err := os.Open(path)
 		if err != nil {
-			return err
+			return nil, err
 		}
+		defer file.Close()
+
+		var keys []ssh.PublicKey
+		scanner := bufio.NewScanner(file)
+		for scanner.Scan() {
+			key, _, _, _, err := ssh.ParseAuthorizedKey(scanner.Bytes())
+			if err != nil {
+				if err.Error() == "ssh: no key found" {
+					continue // Skip line
+				}
+				return nil, err
+			}
+			keys = append(keys, key)
+		}
+		if keys == nil {
+			logger.Warning("file", path, "contained no keys")
+		}
+		return keys, nil
 	}
-	return nil
 }

cmd/ssh-chat/key.go

@@ -4,9 +4,10 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"syscall"
 
-	"github.com/howeyc/gopass"
 	"golang.org/x/crypto/ssh"
+	"golang.org/x/term"
 )
 
 // ReadPrivateKey attempts to read your private key and possibly decrypt it if it
@@ -24,8 +25,8 @@ func ReadPrivateKey(path string) (ssh.Signer, error) {
 	} else if _, ok := err.(*ssh.PassphraseMissingError); ok {
 		passphrase := []byte(os.Getenv("IDENTITY_PASSPHRASE"))
 		if len(passphrase) == 0 {
-			fmt.Print("Enter passphrase: ")
-			passphrase, err = gopass.GetPasswd()
+			fmt.Println("Enter passphrase to unlock identity private key:", path)
+			passphrase, err = term.ReadPassword(int(syscall.Stdin))
 			if err != nil {
 				return nil, fmt.Errorf("couldn't read passphrase: %v", err)
 			}

docker-compose.yml

@@ -0,0 +1,13 @@
+version: '3.2'
+services:
+  app:
+    container_name: ssh-chat
+    build: .
+    ports:
+      - 2022:2022
+    restart: unless-stopped
+    volumes:
+      - type: bind
+        source: ~/.ssh/
+        target: /root/.ssh/
+        read_only: true

go.mod

@@ -2,12 +2,13 @@ module github.com/shazow/ssh-chat
 
 require (
 	github.com/alexcesaro/log v0.0.0-20150915221235-61e686294e58
-	github.com/howeyc/gopass v0.0.0-20190910152052-7cb4b85ec19c
-	github.com/jessevdk/go-flags v1.4.0
+	github.com/jessevdk/go-flags v1.5.0
 	github.com/shazow/rateio v0.0.0-20200113175441-4461efc8bdc4
-	golang.org/x/crypto v0.0.0-20200420104511-884d27f42877
-	golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f
-	golang.org/x/text v0.3.2
+	golang.org/x/crypto v0.17.0
+	golang.org/x/sync v0.1.0
+	golang.org/x/sys v0.15.0
+	golang.org/x/term v0.15.0
+	golang.org/x/text v0.14.0
 )
 
 go 1.13

go.sum

@@ -1,28 +1,50 @@
 github.com/alexcesaro/log v0.0.0-20150915221235-61e686294e58 h1:MkpmYfld/S8kXqTYI68DfL8/hHXjHogL120Dy00TIxc=
 github.com/alexcesaro/log v0.0.0-20150915221235-61e686294e58/go.mod h1:YNfsMyWSs+h+PaYkxGeMVmVCX75Zj/pqdjbu12ciCYE=
-github.com/howeyc/gopass v0.0.0-20170109162249-bf9dde6d0d2c h1:kQWxfPIHVLbgLzphqk3QUflDy9QdksZR4ygR807bpy0=
-github.com/howeyc/gopass v0.0.0-20170109162249-bf9dde6d0d2c/go.mod h1:lADxMC39cJJqL93Duh1xhAs4I2Zs8mKS89XWXFGp9cs=
-github.com/howeyc/gopass v0.0.0-20190910152052-7cb4b85ec19c h1:aY2hhxLhjEAbfXOx2nRJxCXezC6CO2V/yN+OCr1srtk=
-github.com/howeyc/gopass v0.0.0-20190910152052-7cb4b85ec19c/go.mod h1:lADxMC39cJJqL93Duh1xhAs4I2Zs8mKS89XWXFGp9cs=
-github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
-github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
-github.com/shazow/rateio v0.0.0-20150116013248-e8e00881e5c1 h1:Lx3BlDGFElJt4u/zKc9A3BuGYbQAGlEFyPuUA3jeMD0=
-github.com/shazow/rateio v0.0.0-20150116013248-e8e00881e5c1/go.mod h1:vt2jWY/3Qw1bIzle5thrJWucsLuuX9iUNnp20CqCciI=
+github.com/jessevdk/go-flags v1.5.0 h1:1jKYvbxEjfUl0fmqTCOfonvskHHXMjBySTLW4y9LFvc=
+github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
 github.com/shazow/rateio v0.0.0-20200113175441-4461efc8bdc4 h1:zwQ1HBo5FYwn1ksMd19qBCKO8JAWE9wmHivEpkw/DvE=
 github.com/shazow/rateio v0.0.0-20200113175441-4461efc8bdc4/go.mod h1:vt2jWY/3Qw1bIzle5thrJWucsLuuX9iUNnp20CqCciI=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190320223903-b7391e95e576 h1:aUX/1G2gFSs4AsJJg2cL3HuoRhCSCz733FE5GUSuaT4=
-golang.org/x/crypto v0.0.0-20190320223903-b7391e95e576/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200420104511-884d27f42877 h1:IhZPbxNd1UjBCaD5AfpSSbJTRlp+ZSuyuH5uoksNS04=
-golang.org/x/crypto v0.0.0-20200420104511-884d27f42877/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/crypto v0.17.0 h1:r8bRNjWL3GshPW3gkd+RpvzWrZAwPS49OmTGZ/uhM4k=
+golang.org/x/crypto v0.17.0/go.mod h1:gCAAfMLgwOJRpTjQ2zCCt2OcSfYMTeZVSRtQlPC7Nq4=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
+golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190321052220-f7bb7a8bee54 h1:xe1/2UUJRmA9iDglQSlkx8c5n3twv58+K0mPpC2zmhA=
-golang.org/x/sys v0.0.0-20190321052220-f7bb7a8bee54/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f h1:gWF768j/LaZugp8dyS4UwsslYCYz9XgFxvlgsn0n9H8=
-golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
+golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
+golang.org/x/term v0.15.0 h1:y/Oo/a/q3IXu26lQgl04j/gjuBDOBlx7X6Om1j2CPW4=
+golang.org/x/term v0.15.0/go.mod h1:BDl952bC7+uMoWR75FIrCDx79TPU9oHkTZ9yRbYOrX0=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
-golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

host.go

@@ -9,11 +9,14 @@ import (
 	"sync"
 	"time"
 
+	"golang.org/x/crypto/ssh"
+
 	"github.com/shazow/rateio"
 	"github.com/shazow/ssh-chat/chat"
 	"github.com/shazow/ssh-chat/chat/message"
 	"github.com/shazow/ssh-chat/internal/humantime"
 	"github.com/shazow/ssh-chat/internal/sanitize"
+	"github.com/shazow/ssh-chat/set"
 	"github.com/shazow/ssh-chat/sshd"
 )
 
@@ -49,6 +52,8 @@ type Host struct {
 
 	// GetMOTD is used to reload the motd from an external source
 	GetMOTD func() (string, error)
+	// OnUserJoined is used to notify when a user joins a host
+	OnUserJoined func(*message.User)
 }
 
 // NewHost creates a Host on top of an existing listener.
@@ -114,6 +119,33 @@ func (h *Host) Connect(term *sshd.Terminal) {
 	}
 
 	user.SetConfig(cfg)
+	go user.Consume()
+
+	// Close term once user is closed.
+	defer user.Close()
+	defer term.Close()
+
+	h.mu.Lock()
+	motd := h.motd
+	count := h.count
+	h.count++
+	h.mu.Unlock()
+
+	// Send MOTD
+	if motd != "" && !apiMode {
+		user.Send(message.NewAnnounceMsg(motd))
+	}
+
+	member, err := h.Join(user)
+	if err != nil {
+		// Try again...
+		id.SetName(fmt.Sprintf("Guest%d", count))
+		member, err = h.Join(user)
+	}
+	if err != nil {
+		logger.Errorf("[%s] Failed to join: %s", term.Conn.RemoteAddr(), err)
+		return
+	}
 
 	// Load user config overrides from ENV
 	// TODO: Would be nice to skip the command parsing pipeline just to load
@@ -140,34 +172,6 @@ func (h *Host) Connect(term *sshd.Terminal) {
 		}
 	}
 
-	go user.Consume()
-
-	// Close term once user is closed.
-	defer user.Close()
-	defer term.Close()
-
-	h.mu.Lock()
-	motd := h.motd
-	count := h.count
-	h.count++
-	h.mu.Unlock()
-
-	// Send MOTD
-	if motd != "" {
-		user.Send(message.NewAnnounceMsg(motd))
-	}
-
-	member, err := h.Join(user)
-	if err != nil {
-		// Try again...
-		id.SetName(fmt.Sprintf("Guest%d", count))
-		member, err = h.Join(user)
-	}
-	if err != nil {
-		logger.Errorf("[%s] Failed to join: %s", term.Conn.RemoteAddr(), err)
-		return
-	}
-
 	// Successfully joined.
 	if !apiMode {
 		term.SetPrompt(GetPrompt(user))
@@ -183,6 +187,10 @@ func (h *Host) Connect(term *sshd.Terminal) {
 
 	logger.Debugf("[%s] Joined: %s", term.Conn.RemoteAddr(), user.Name())
 
+	if h.OnUserJoined != nil {
+		h.OnUserJoined(user)
+	}
+
 	for {
 		line, err := term.ReadLine()
 		if err == io.EOF {
@@ -334,6 +342,20 @@ func (h *Host) GetUser(name string) (*message.User, bool) {
 // InitCommands adds host-specific commands to a Commands container. These will
 // override any existing commands.
 func (h *Host) InitCommands(c *chat.Commands) {
+	sendPM := func(room *chat.Room, msg string, from *message.User, target *message.User) error {
+		m := message.NewPrivateMsg(msg, from, target)
+		room.Send(&m)
+
+		txt := fmt.Sprintf("[Sent PM to %s]", target.Name())
+		if isAway, _, awayReason := target.GetAway(); isAway {
+			txt += " Away: " + awayReason
+		}
+		sysMsg := message.NewSystemMsg(txt, from)
+		room.Send(sysMsg)
+		target.SetReplyTo(from)
+		return nil
+	}
+
 	c.Add(chat.Command{
 		Prefix:     "/msg",
 		PrefixHelp: "USER MESSAGE",
@@ -352,14 +374,7 @@ func (h *Host) InitCommands(c *chat.Commands) {
 				return errors.New("user not found")
 			}
 
-			m := message.NewPrivateMsg(strings.Join(args[1:], " "), msg.From(), target)
-			room.Send(&m)
-
-			txt := fmt.Sprintf("[Sent PM to %s]", target.Name())
-			ms := message.NewSystemMsg(txt, msg.From())
-			room.Send(ms)
-			target.SetReplyTo(msg.From())
-			return nil
+			return sendPM(room, strings.Join(args[1:], " "), msg.From(), target)
 		},
 	})
 
@@ -379,20 +394,12 @@ func (h *Host) InitCommands(c *chat.Commands) {
 				return errors.New("no message to reply to")
 			}
 
-			name := target.Name()
-			_, found := h.GetUser(name)
+			_, found := h.GetUser(target.ID())
 			if !found {
 				return errors.New("user not found")
 			}
 
-			m := message.NewPrivateMsg(strings.Join(args, " "), msg.From(), target)
-			room.Send(&m)
-
-			txt := fmt.Sprintf("[Sent PM to %s]", name)
-			ms := message.NewSystemMsg(txt, msg.From())
-			room.Send(ms)
-			target.SetReplyTo(msg.From())
-			return nil
+			return sendPM(room, strings.Join(args, " "), msg.From(), target)
 		},
 	})
 
@@ -416,7 +423,7 @@ func (h *Host) InitCommands(c *chat.Commands) {
 			case true:
 				whois = id.WhoisAdmin(room)
 			case false:
-				whois = id.Whois()
+				whois = id.Whois(room)
 			}
 			room.Send(message.NewSystemMsg(whois, msg.From()))
 
@@ -509,7 +516,7 @@ func (h *Host) InitCommands(c *chat.Commands) {
 			room.Send(message.NewAnnounceMsg(body))
 			target.Close()
 
-			logger.Debugf("Banned: \n-> %s", id.Whois())
+			logger.Debugf("Banned: \n-> %s", id.Whois(room))
 
 			return nil
 		},
@@ -691,4 +698,202 @@ func (h *Host) InitCommands(c *chat.Commands) {
 			return nil
 		},
 	})
+
+	forConnectedUsers := func(cmd func(*chat.Member, ssh.PublicKey) error) error {
+		return h.Members.Each(func(key string, item set.Item) error {
+			v := item.Value()
+			if v == nil { // expired between Each and here
+				return nil
+			}
+			user := v.(*chat.Member)
+			pk := user.Identifier.(*Identity).PublicKey()
+			return cmd(user, pk)
+		})
+	}
+
+	forPubkeyUser := func(args []string, cmd func(ssh.PublicKey)) (errors []string) {
+		invalidUsers := []string{}
+		invalidKeys := []string{}
+		noKeyUsers := []string{}
+		var keyType string
+		for _, v := range args {
+			switch {
+			case keyType != "":
+				pk, _, _, _, err := ssh.ParseAuthorizedKey([]byte(keyType + " " + v))
+				if err == nil {
+					cmd(pk)
+				} else {
+					invalidKeys = append(invalidKeys, keyType+" "+v)
+				}
+				keyType = ""
+			case strings.HasPrefix(v, "ssh-"):
+				keyType = v
+			default:
+				user, ok := h.GetUser(v)
+				if ok {
+					pk := user.Identifier.(*Identity).PublicKey()
+					if pk == nil {
+						noKeyUsers = append(noKeyUsers, user.Identifier.Name())
+					} else {
+						cmd(pk)
+					}
+				} else {
+					invalidUsers = append(invalidUsers, v)
+				}
+			}
+		}
+		if len(noKeyUsers) != 0 {
+			errors = append(errors, fmt.Sprintf("users without a public key: %v", noKeyUsers))
+		}
+		if len(invalidUsers) != 0 {
+			errors = append(errors, fmt.Sprintf("invalid users: %v", invalidUsers))
+		}
+		if len(invalidKeys) != 0 {
+			errors = append(errors, fmt.Sprintf("invalid keys: %v", invalidKeys))
+		}
+		return
+	}
+
+	allowlistHelptext := []string{
+		"Usage: /allowlist help | on | off | add {PUBKEY|USER}... | remove {PUBKEY|USER}... | import [AGE] | reload {keep|flush} | reverify | status",
+		"help: this help message",
+		"on, off: set allowlist mode (applies to new connections)",
+		"add, remove: add or remove keys from the allowlist",
+		"import: add all keys of users connected since AGE (default 0) ago to the allowlist",
+		"reload: re-read the allowlist file and keep or discard entries in the current allowlist but not in the file",
+		"reverify: kick all users not in the allowlist if allowlisting is enabled",
+		"status: show status information",
+	}
+
+	allowlistImport := func(args []string) (msgs []string, err error) {
+		var since time.Duration
+		if len(args) > 0 {
+			since, err = time.ParseDuration(args[0])
+			if err != nil {
+				return
+			}
+		}
+		cutoff := time.Now().Add(-since)
+		noKeyUsers := []string{}
+		forConnectedUsers(func(user *chat.Member, pk ssh.PublicKey) error {
+			if user.Joined().Before(cutoff) {
+				if pk == nil {
+					noKeyUsers = append(noKeyUsers, user.Identifier.Name())
+				} else {
+					h.auth.Allowlist(pk, 0)
+				}
+			}
+			return nil
+		})
+		if len(noKeyUsers) != 0 {
+			msgs = []string{fmt.Sprintf("users without a public key: %v", noKeyUsers)}
+		}
+		return
+	}
+
+	allowlistReload := func(args []string) error {
+		if !(len(args) > 0 && (args[0] == "keep" || args[0] == "flush")) {
+			return errors.New("must specify whether to keep or flush current entries")
+		}
+		if args[0] == "flush" {
+			h.auth.allowlist.Clear()
+		}
+		return h.auth.ReloadAllowlist()
+	}
+
+	allowlistReverify := func(room *chat.Room) []string {
+		if !h.auth.AllowlistMode() {
+			return []string{"allowlist is disabled, so nobody will be kicked"}
+		}
+		var kicked []string
+		forConnectedUsers(func(user *chat.Member, pk ssh.PublicKey) error {
+			if h.auth.CheckPublicKey(pk) != nil && !user.IsOp { // we do this check here as well for ops without keys
+				kicked = append(kicked, user.Name())
+				user.Close()
+			}
+			return nil
+		})
+		if kicked != nil {
+			room.Send(message.NewAnnounceMsg("Kicked during pubkey reverification: " + strings.Join(kicked, ", ")))
+		}
+		return nil
+	}
+
+	allowlistStatus := func() (msgs []string) {
+		if h.auth.AllowlistMode() {
+			msgs = []string{"allowlist enabled"}
+		} else {
+			msgs = []string{"allowlist disabled"}
+		}
+		allowlistedUsers := []string{}
+		allowlistedKeys := []string{}
+		h.auth.allowlist.Each(func(key string, item set.Item) error {
+			keyFP := item.Key()
+			if forConnectedUsers(func(user *chat.Member, pk ssh.PublicKey) error {
+				if pk != nil && sshd.Fingerprint(pk) == keyFP {
+					allowlistedUsers = append(allowlistedUsers, user.Name())
+					return io.EOF
+				}
+				return nil
+			}) == nil {
+				// if we land here, the key matches no users
+				allowlistedKeys = append(allowlistedKeys, keyFP)
+			}
+			return nil
+		})
+		if len(allowlistedUsers) != 0 {
+			msgs = append(msgs, "Connected users on the allowlist: "+strings.Join(allowlistedUsers, ", "))
+		}
+		if len(allowlistedKeys) != 0 {
+			msgs = append(msgs, "Keys on the allowlist without connected user: "+strings.Join(allowlistedKeys, ", "))
+		}
+		return
+	}
+
+	c.Add(chat.Command{
+		Op:         true,
+		Prefix:     "/allowlist",
+		PrefixHelp: "COMMAND [ARGS...]",
+		Help:       "Modify the allowlist or allowlist state. See /allowlist help for subcommands",
+		Handler: func(room *chat.Room, msg message.CommandMsg) (err error) {
+			if !room.IsOp(msg.From()) {
+				return errors.New("must be op")
+			}
+
+			args := msg.Args()
+			if len(args) == 0 {
+				args = []string{"help"}
+			}
+
+			// send exactly one message to preserve order
+			var replyLines []string
+
+			switch args[0] {
+			case "help":
+				replyLines = allowlistHelptext
+			case "on":
+				h.auth.SetAllowlistMode(true)
+			case "off":
+				h.auth.SetAllowlistMode(false)
+			case "add":
+				replyLines = forPubkeyUser(args[1:], func(pk ssh.PublicKey) { h.auth.Allowlist(pk, 0) })
+			case "remove":
+				replyLines = forPubkeyUser(args[1:], func(pk ssh.PublicKey) { h.auth.Allowlist(pk, 1) })
+			case "import":
+				replyLines, err = allowlistImport(args[1:])
+			case "reload":
+				err = allowlistReload(args[1:])
+			case "reverify":
+				replyLines = allowlistReverify(room)
+			case "status":
+				replyLines = allowlistStatus()
+			default:
+				err = errors.New("invalid subcommand: " + args[0])
+			}
+			if err == nil && replyLines != nil {
+				room.Send(message.NewSystemMsg(strings.Join(replyLines, "\r\n"), msg.From()))
+			}
+			return
+		},
+	})
 }

host_test.go

@@ -2,9 +2,8 @@ package sshchat
 
 import (
 	"bufio"
-	"crypto/rand"
-	"crypto/rsa"
 	"errors"
+	"fmt"
 	"io"
 	mathRand "math/rand"
 	"strings"
@@ -13,6 +12,7 @@ import (
 	"github.com/shazow/ssh-chat/chat/message"
 	"github.com/shazow/ssh-chat/sshd"
 	"golang.org/x/crypto/ssh"
+	"golang.org/x/sync/errgroup"
 )
 
 func stripPrompt(s string) string {
@@ -23,9 +23,15 @@ func stripPrompt(s string) string {
 	if endPos := strings.Index(s, "\x1b[2K "); endPos > 0 {
 		return s[endPos+4:]
 	}
+	if endPos := strings.Index(s, "\x1b[K-> "); endPos > 0 {
+		return s[endPos+6:]
+	}
 	if endPos := strings.Index(s, "] "); endPos > 0 {
 		return s[endPos+2:]
 	}
+	if strings.HasPrefix(s, "-> ") {
+		return s[3:]
+	}
 	return s
 }
 
@@ -42,6 +48,14 @@ func TestStripPrompt(t *testing.T) {
 			Input: "[foo] \x1b[D\x1b[D\x1b[D\x1b[D\x1b[D\x1b[D\x1b[K * Guest1 joined. (Connected: 2)\r",
 			Want:  " * Guest1 joined. (Connected: 2)\r",
 		},
+		{
+			Input: "[foo] \x1b[6D\x1b[K-> From your friendly system.\r",
+			Want:  "From your friendly system.\r",
+		},
+		{
+			Input: "-> Err: must be op.\r",
+			Want:  "Err: must be op.\r",
+		},
 	}
 
 	for i, tc := range tests {
@@ -75,153 +89,263 @@ func TestHostGetPrompt(t *testing.T) {
 	}
 }
 
-func TestHostNameCollision(t *testing.T) {
-	key, err := sshd.NewRandomSigner(512)
+func getHost(t *testing.T, auth *Auth) (*sshd.SSHListener, *Host) {
+	key, err := sshd.NewRandomSigner(1024)
 	if err != nil {
 		t.Fatal(err)
 	}
-	config := sshd.MakeNoAuth()
+	var config *ssh.ServerConfig
+	if auth == nil {
+		config = sshd.MakeNoAuth()
+	} else {
+		config = sshd.MakeAuth(auth)
+	}
 	config.AddHostKey(key)
 
 	s, err := sshd.ListenSSH("localhost:0", config)
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer s.Close()
-	host := NewHost(s, nil)
-	go host.Serve()
-
-	done := make(chan struct{}, 1)
-
-	// First client
-	go func() {
-		err := sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
-			scanner := bufio.NewScanner(r)
-
-			// Consume the initial buffer
-			scanner.Scan()
-			actual := stripPrompt(scanner.Text())
-			expected := " * foo joined. (Connected: 1)\r"
-			if actual != expected {
-				t.Errorf("Got %q; expected %q", actual, expected)
-			}
-
-			// Ready for second client
-			done <- struct{}{}
-
-			scanner.Scan()
-			actual = scanner.Text()
-			// This check has to happen second because prompt doesn't always
-			// get set before the first message.
-			if !strings.HasPrefix(actual, "[foo] ") {
-				t.Errorf("First client failed to get 'foo' name: %q", actual)
-			}
-			actual = stripPrompt(actual)
-			expected = " * Guest1 joined. (Connected: 2)\r"
-			if actual != expected {
-				t.Errorf("Got %q; expected %q", actual, expected)
-			}
-
-			// Wrap it up.
-			close(done)
-			return nil
-		})
-		if err != nil {
-			done <- struct{}{}
-			t.Fatal(err)
-		}
-	}()
-
-	// Wait for first client
-	<-done
-
-	// Second client
-	err = sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
-		scanner := bufio.NewScanner(r)
-
-		// Consume the initial buffer
-		scanner.Scan()
-		scanner.Scan()
-		scanner.Scan()
-
-		actual := scanner.Text()
-		if !strings.HasPrefix(actual, "[Guest1] ") {
-			t.Errorf("Second client did not get Guest1 name: %q", actual)
-		}
-		return nil
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	<-done
+	return s, NewHost(s, auth)
 }
 
-func TestHostWhitelist(t *testing.T) {
-	key, err := sshd.NewRandomSigner(512)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	auth := NewAuth()
-	config := sshd.MakeAuth(auth)
-	config.AddHostKey(key)
-
-	s, err := sshd.ListenSSH("localhost:0", config)
-	if err != nil {
-		t.Fatal(err)
-	}
+func TestHostNameCollision(t *testing.T) {
+	s, host := getHost(t, nil)
+	defer s.Close()
+
+	newUsers := make(chan *message.User)
+	host.OnUserJoined = func(u *message.User) {
+		newUsers <- u
+	}
+	go host.Serve()
+
+	g := errgroup.Group{}
+
+	// First client
+	g.Go(func() error {
+		return sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
+			// second client
+			name := (<-newUsers).Name()
+			if name != "Guest1" {
+				t.Errorf("Second client did not get Guest1 name: %q", name)
+			}
+			return nil
+		})
+	})
+
+	// Second client
+	g.Go(func() error {
+		// first client
+		name := (<-newUsers).Name()
+		if name != "foo" {
+			t.Errorf("First client did not get foo name: %q", name)
+		}
+		return sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
+			return nil
+		})
+	})
+
+	if err := g.Wait(); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestHostAllowlist(t *testing.T) {
+	auth := NewAuth()
+	s, host := getHost(t, auth)
 	defer s.Close()
-	host := NewHost(s, auth)
 	go host.Serve()
 
 	target := s.Addr().String()
 
+	clientPrivateKey, err := sshd.NewRandomSigner(512)
+	if err != nil {
+		t.Fatal(err)
+	}
+	clientKey := clientPrivateKey.PublicKey()
+	loadCount := -1
+	loader := func() ([]ssh.PublicKey, error) {
+		loadCount++
+		return [][]ssh.PublicKey{
+			{},
+			{clientKey},
+		}[loadCount], nil
+	}
+	auth.LoadAllowlist(loader)
+
 	err = sshd.ConnectShell(target, "foo", func(r io.Reader, w io.WriteCloser) error { return nil })
 	if err != nil {
 		t.Error(err)
 	}
 
-	clientkey, err := rsa.GenerateKey(rand.Reader, 512)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	clientpubkey, _ := ssh.NewPublicKey(clientkey.Public())
-	auth.Whitelist(clientpubkey, 0)
-
+	auth.SetAllowlistMode(true)
 	err = sshd.ConnectShell(target, "foo", func(r io.Reader, w io.WriteCloser) error { return nil })
 	if err == nil {
-		t.Error("Failed to block unwhitelisted connection.")
+		t.Error(err)
+	}
+	err = sshd.ConnectShellWithKey(target, "foo", clientPrivateKey, func(r io.Reader, w io.WriteCloser) error { return nil })
+	if err == nil {
+		t.Error(err)
+	}
+
+	auth.ReloadAllowlist()
+	err = sshd.ConnectShell(target, "foo", func(r io.Reader, w io.WriteCloser) error { return nil })
+	if err == nil {
+		t.Error("Failed to block unallowlisted connection.")
 	}
 }
 
-func TestHostKick(t *testing.T) {
-	key, err := sshd.NewRandomSigner(512)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	auth := NewAuth()
-	config := sshd.MakeAuth(auth)
-	config.AddHostKey(key)
-
-	s, err := sshd.ListenSSH("localhost:0", config)
-	if err != nil {
-		t.Fatal(err)
-	}
+func TestHostAllowlistCommand(t *testing.T) {
+	s, host := getHost(t, NewAuth())
 	defer s.Close()
-	addr := s.Addr().String()
-	host := NewHost(s, nil)
 	go host.Serve()
 
+	users := make(chan *message.User)
+	host.OnUserJoined = func(u *message.User) {
+		users <- u
+	}
+
+	kickSignal := make(chan struct{})
+	clientKey, err := sshd.NewRandomSigner(1024)
+	if err != nil {
+		t.Fatal(err)
+	}
+	clientKeyFP := sshd.Fingerprint(clientKey.PublicKey())
+	go sshd.ConnectShellWithKey(s.Addr().String(), "bar", clientKey, func(r io.Reader, w io.WriteCloser) error {
+		<-kickSignal
+		n, err := w.Write([]byte("alive and well"))
+		if n != 0 || err == nil {
+			t.Error("could write after being kicked")
+		}
+		return nil
+	})
+
+	sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
+		<-users
+		<-users
+		m, ok := host.MemberByID("foo")
+		if !ok {
+			t.Fatal("can't get member foo")
+		}
+
+		scanner := bufio.NewScanner(r)
+		scanner.Scan() // Joined
+		scanner.Scan()
+
+		assertLineEq := func(expected ...string) {
+			if !scanner.Scan() {
+				t.Error("no line available")
+			}
+			actual := stripPrompt(scanner.Text())
+			for _, exp := range expected {
+				if exp == actual {
+					return
+				}
+			}
+			t.Errorf("expected %#v, got %q", expected, actual)
+		}
+		sendCmd := func(cmd string, formatting ...interface{}) {
+			host.HandleMsg(message.ParseInput(fmt.Sprintf(cmd, formatting...), m.User))
+		}
+
+		sendCmd("/allowlist")
+		assertLineEq("Err: must be op\r")
+		m.IsOp = true
+		sendCmd("/allowlist")
+		for _, expected := range [...]string{"Usage", "help", "on, off", "add, remove", "import", "reload", "reverify", "status"} {
+			if !scanner.Scan() {
+				t.Error("no line available")
+			}
+			if actual := stripPrompt(scanner.Text()); !strings.HasPrefix(actual, expected) {
+				t.Errorf("Unexpected help message order: have %q, want prefix %q", actual, expected)
+			}
+		}
+
+		sendCmd("/allowlist on")
+		if !host.auth.AllowlistMode() {
+			t.Error("allowlist not enabled after /allowlist on")
+		}
+		sendCmd("/allowlist off")
+		if host.auth.AllowlistMode() {
+			t.Error("allowlist not disabled after /allowlist off")
+		}
+
+		testKey := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPUiNw0nQku4pcUCbZcJlIEAIf5bXJYTy/DKI1vh5b+P"
+		testKeyFP := "SHA256:GJNSl9NUcOS2pZYALn0C5Qgfh5deT+R+FfqNIUvpM9s="
+
+		if host.auth.allowlist.Len() != 0 {
+			t.Error("allowlist not empty before adding anyone")
+		}
+		sendCmd("/allowlist add ssh-invalid blah ssh-rsa wrongAsWell invalid foo bar %s", testKey)
+		assertLineEq("users without a public key: [foo]\r")
+		assertLineEq("invalid users: [invalid]\r")
+		assertLineEq("invalid keys: [ssh-invalid blah ssh-rsa wrongAsWell]\r")
+		if !host.auth.allowlist.In(testKeyFP) || !host.auth.allowlist.In(clientKeyFP) {
+			t.Error("failed to add keys to allowlist")
+		}
+		sendCmd("/allowlist remove invalid bar")
+		assertLineEq("invalid users: [invalid]\r")
+		if host.auth.allowlist.In(clientKeyFP) {
+			t.Error("failed to remove key from allowlist")
+		}
+		if !host.auth.allowlist.In(testKeyFP) {
+			t.Error("removed wrong key")
+		}
+
+		sendCmd("/allowlist import 5h")
+		if host.auth.allowlist.In(clientKeyFP) {
+			t.Error("imporrted key not seen long enough")
+		}
+		sendCmd("/allowlist import")
+		assertLineEq("users without a public key: [foo]\r")
+		if !host.auth.allowlist.In(clientKeyFP) {
+			t.Error("failed to import key")
+		}
+
+		sendCmd("/allowlist reload keep")
+		if !host.auth.allowlist.In(testKeyFP) {
+			t.Error("cleared allowlist to be kept")
+		}
+		sendCmd("/allowlist reload flush")
+		if host.auth.allowlist.In(testKeyFP) {
+			t.Error("kept allowlist to be cleared")
+		}
+		sendCmd("/allowlist reload thisIsWrong")
+		assertLineEq("Err: must specify whether to keep or flush current entries\r")
+		sendCmd("/allowlist reload")
+		assertLineEq("Err: must specify whether to keep or flush current entries\r")
+
+		sendCmd("/allowlist reverify")
+		assertLineEq("allowlist is disabled, so nobody will be kicked\r")
+		sendCmd("/allowlist on")
+		sendCmd("/allowlist reverify")
+		assertLineEq(" * Kicked during pubkey reverification: bar\r", " * bar left. (After 0 seconds)\r")
+		assertLineEq(" * Kicked during pubkey reverification: bar\r", " * bar left. (After 0 seconds)\r")
+		kickSignal <- struct{}{}
+
+		sendCmd("/allowlist add " + testKey)
+		sendCmd("/allowlist status")
+		assertLineEq("allowlist enabled\r")
+		assertLineEq(fmt.Sprintf("Keys on the allowlist without connected user: %s\r", testKeyFP))
+
+		sendCmd("/allowlist invalidSubcommand")
+		assertLineEq("Err: invalid subcommand: invalidSubcommand\r")
+		return nil
+	})
+}
+
+func TestHostKick(t *testing.T) {
+	s, host := getHost(t, NewAuth())
+	defer s.Close()
+	go host.Serve()
+
+	g := errgroup.Group{}
 	connected := make(chan struct{})
 	kicked := make(chan struct{})
-	done := make(chan struct{})
 
-	go func() {
+	g.Go(func() error {
 		// First client
-		err := sshd.ConnectShell(addr, "foo", func(r io.Reader, w io.WriteCloser) error {
+		return sshd.ConnectShell(s.Addr().String(), "foo", func(r io.Reader, w io.WriteCloser) error {
 			scanner := bufio.NewScanner(r)
 
 			// Consume the initial buffer
@@ -252,41 +376,103 @@ func TestHostKick(t *testing.T) {
 			}
 
 			kicked <- struct{}{}
-
 			return nil
 		})
-		if err != nil {
-			connected <- struct{}{}
-			close(connected)
-			t.Fatal(err)
-			close(done)
-		}
-	}()
+	})
 
-	go func() {
+	g.Go(func() error {
 		// Second client
-		err := sshd.ConnectShell(addr, "bar", func(r io.Reader, w io.WriteCloser) error {
+		return sshd.ConnectShell(s.Addr().String(), "bar", func(r io.Reader, w io.WriteCloser) error {
 			scanner := bufio.NewScanner(r)
 			<-connected
 			scanner.Scan()
 
 			<-kicked
 
-			if _, err := w.Write([]byte("am I still here?\r\n")); err != nil {
-				return err
+			if _, err := w.Write([]byte("am I still here?\r\n")); err != io.EOF {
+				return errors.New("expected to be kicked")
 			}
 
 			scanner.Scan()
-			return scanner.Err()
+			if err := scanner.Err(); err == io.EOF {
+				// All good, we got kicked.
+				return nil
+			} else {
+				return err
+			}
 		})
-		if err == io.EOF {
-			// All good, we got kicked.
-		} else if err != nil {
-			close(done)
-			t.Fatal(err)
-		}
-		close(done)
-	}()
+	})
 
-	<-done
+	if err := g.Wait(); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestTimestampEnvConfig(t *testing.T) {
+	cases := []struct {
+		input      string
+		timeformat *string
+	}{
+		{"", strptr("15:04")},
+		{"1", strptr("15:04")},
+		{"0", nil},
+		{"time +8h", strptr("15:04")},
+		{"datetime +8h", strptr("2006-01-02 15:04:05")},
+	}
+	for _, tc := range cases {
+		u := connectUserWithConfig(t, "dingus", map[string]string{
+			"SSHCHAT_TIMESTAMP": tc.input,
+		})
+		userConfig := u.Config()
+		if userConfig.Timeformat != nil && tc.timeformat != nil {
+			if *userConfig.Timeformat != *tc.timeformat {
+				t.Fatal("unexpected timeformat:", *userConfig.Timeformat, "expected:", *tc.timeformat)
+			}
+		}
+	}
+}
+
+func strptr(s string) *string {
+	return &s
+}
+
+func connectUserWithConfig(t *testing.T, name string, envConfig map[string]string) *message.User {
+	s, host := getHost(t, nil)
+	defer s.Close()
+
+	newUsers := make(chan *message.User)
+	host.OnUserJoined = func(u *message.User) {
+		newUsers <- u
+	}
+	go host.Serve()
+
+	clientConfig := sshd.NewClientConfig(name)
+	conn, err := ssh.Dial("tcp", s.Addr().String(), clientConfig)
+	if err != nil {
+		t.Fatal("unable to connect to test ssh-chat server:", err)
+	}
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatal("unable to open session:", err)
+	}
+	defer session.Close()
+
+	for key := range envConfig {
+		session.Setenv(key, envConfig[key])
+	}
+
+	err = session.Shell()
+	if err != nil {
+		t.Fatal("unable to open shell:", err)
+	}
+
+	for u := range newUsers {
+		if u.Name() == name {
+			return u
+		}
+	}
+	t.Fatalf("user %s not found in the host", name)
+	return nil
 }

identity.go

@@ -1,6 +1,7 @@
 package sshchat
 
 import (
+	"fmt"
 	"net"
 	"strings"
 	"time"
@@ -57,16 +58,25 @@ func (i Identity) Name() string {
 }
 
 // Whois returns a whois description for non-admin users.
-// TODO: Add optional room context?
-func (i Identity) Whois() string {
+func (i Identity) Whois(room *chat.Room) string {
 	fingerprint := "(no public key)"
 	if i.PublicKey() != nil {
 		fingerprint = sshd.Fingerprint(i.PublicKey())
 	}
+	// TODO: Rewrite this using strings.Builder like WhoisAdmin
+
+	awayMsg := ""
+	if m, ok := room.MemberByID(i.ID()); ok {
+		isAway, awaySince, awayMessage := m.GetAway()
+		if isAway {
+			awayMsg = fmt.Sprintf("%s > away: (%s ago) %s", message.Newline, humantime.Since(awaySince), awayMessage)
+		}
+	}
 	return "name: " + i.Name() + message.Newline +
 		" > fingerprint: " + fingerprint + message.Newline +
 		" > client: " + sanitize.Data(string(i.ClientVersion()), 64) + message.Newline +
-		" > joined: " + humantime.Since(i.created) + " ago"
+		" > joined: " + humantime.Since(i.created) + " ago" +
+		awayMsg
 }
 
 // WhoisAdmin returns a whois description for admin users.
@@ -86,6 +96,9 @@ func (i Identity) WhoisAdmin(room *chat.Room) string {
 
 	if member, ok := room.MemberByID(i.ID()); ok {
 		// Add room-specific whois
+		if isAway, awaySince, awayMessage := member.GetAway(); isAway {
+			fmt.Fprintf(&out, message.Newline+" > away: (%s ago) %s", humantime.Since(awaySince), awayMessage)
+		}
 		// FIXME: Should these always be present, even if they're false? Maybe
 		// change that once we add room context to Whois() above.
 		if !member.LastMsg().IsZero() {

issue_template.md

@@ -1,8 +0,0 @@
-### Expected Behavior
-
-### Actual Behavior
-
-### Steps to reproduce behavior
-
-
-### Additional Comments

set/set.go

@@ -12,9 +12,6 @@ var ErrCollision = errors.New("key already exists")
 // Returned when a requested item does not exist in the set.
 var ErrMissing = errors.New("item does not exist")
 
-// Returned when a nil item is added. Nil values are considered expired and invalid.
-var ErrNil = errors.New("item value must not be nil")
-
 // ZeroValue can be used when we only care about the key, not about the value.
 var ZeroValue = struct{}{}
 
@@ -100,7 +97,7 @@ func (s *Set) Get(key string) (Item, error) {
 func (s *Set) cleanup(key string) {
 	s.Lock()
 	item, ok := s.lookup[key]
-	if ok && item == nil {
+	if ok && item.Value() == nil {
 		delete(s.lookup, key)
 	}
 	s.Unlock()
@@ -108,9 +105,6 @@ func (s *Set) cleanup(key string) {
 
 // Add item to this set if it does not exist already.
 func (s *Set) Add(item Item) error {
-	if item.Value() == nil {
-		return ErrNil
-	}
 	key := s.normalize(item.Key())
 
 	s.Lock()
@@ -127,9 +121,6 @@ func (s *Set) Add(item Item) error {
 
 // Set item to this set, even if it already exists.
 func (s *Set) Set(item Item) error {
-	if item.Value() == nil {
-		return ErrNil
-	}
 	key := s.normalize(item.Key())
 
 	s.Lock()
@@ -156,9 +147,6 @@ func (s *Set) Remove(key string) error {
 // Replace oldKey with a new item, which might be a new key.
 // Can be used to rename items.
 func (s *Set) Replace(oldKey string, item Item) error {
-	if item.Value() == nil {
-		return ErrNil
-	}
 	newKey := s.normalize(item.Key())
 	oldKey = s.normalize(oldKey)
 

set/set_test.go

@@ -21,14 +21,23 @@ func TestSetExpiring(t *testing.T) {
 		t.Error("not len 1 after set")
 	}
 
-	item := &ExpiringItem{nil, time.Now().Add(-time.Nanosecond * 1)}
+	item := Expire(StringItem("asdf"), -time.Nanosecond).(*ExpiringItem)
 	if !item.Expired() {
 		t.Errorf("ExpiringItem a nanosec ago is not expiring")
 	}
+	if err := s.Add(item); err != nil {
+		t.Error("Error adding expired item to set: ", err)
+	}
+	if s.In("asdf") {
+		t.Error("Expired item in set")
+	}
+	if s.Len() != 1 {
+		t.Error("not len 1 after expired item")
+	}
 
 	item = &ExpiringItem{nil, time.Now().Add(time.Minute * 5)}
 	if item.Expired() {
-		t.Errorf("ExpiringItem in 2 minutes is expiring now")
+		t.Errorf("ExpiringItem in 5 minutes is expiring now")
 	}
 
 	item = Expire(StringItem("bar"), time.Minute*5).(*ExpiringItem)
@@ -42,11 +51,13 @@ func TestSetExpiring(t *testing.T) {
 	if err := s.Add(item); err != nil {
 		t.Fatalf("failed to add item: %s", err)
 	}
-	_, ok := s.lookup["bar"]
+	itemInLookup, ok := s.lookup["bar"]
 	if !ok {
-		t.Fatalf("expired bar added to lookup")
+		t.Fatalf("bar not present in lookup even though it's not expired")
+	}
+	if itemInLookup != item {
+		t.Fatalf("present item %#v != %#v original item", itemInLookup, item)
 	}
-	s.lookup["bar"] = item
 
 	if !s.In("bar") {
 		t.Errorf("not matched after timed set")

sshd/auth.go

@@ -5,17 +5,26 @@ import (
 	"encoding/base64"
 	"errors"
 	"net"
+	"time"
 
 	"github.com/shazow/ssh-chat/internal/sanitize"
 	"golang.org/x/crypto/ssh"
 )
 
-// Auth is used to authenticate connections based on public keys.
+// Auth is used to authenticate connections.
 type Auth interface {
 	// Whether to allow connections without a public key.
 	AllowAnonymous() bool
-	// Given address and public key and client agent string, returns nil if the connection should be allowed.
-	Check(net.Addr, ssh.PublicKey, string) error
+	// If passphrase authentication is accepted
+	AcceptPassphrase() bool
+	// Given address and public key and client agent string, returns nil if the connection is not banned.
+	CheckBans(net.Addr, ssh.PublicKey, string) error
+	// Given a public key, returns nil if the connection should be allowed.
+	CheckPublicKey(ssh.PublicKey) error
+	// Given a passphrase, returns nil if the connection should be allowed.
+	CheckPassphrase(string) error
+	// BanAddr bans an IP address for the specified amount of time.
+	BanAddr(net.Addr, time.Duration)
 }
 
 // MakeAuth makes an ssh.ServerConfig which performs authentication against an Auth implementation.
@@ -25,7 +34,11 @@ func MakeAuth(auth Auth) *ssh.ServerConfig {
 		NoClientAuth: false,
 		// Auth-related things should be constant-time to avoid timing attacks.
 		PublicKeyCallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
-			err := auth.Check(conn.RemoteAddr(), key, sanitize.Data(string(conn.ClientVersion()), 64))
+			err := auth.CheckBans(conn.RemoteAddr(), key, sanitize.Data(string(conn.ClientVersion()), 64))
+			if err != nil {
+				return nil, err
+			}
+			err = auth.CheckPublicKey(key)
 			if err != nil {
 				return nil, err
 			}
@@ -34,11 +47,31 @@ func MakeAuth(auth Auth) *ssh.ServerConfig {
 			}}
 			return perm, nil
 		},
+
+		// We use KeyboardInteractiveCallback instead of PasswordCallback to
+		// avoid preventing the client from including a pubkey in the user
+		// identification.
 		KeyboardInteractiveCallback: func(conn ssh.ConnMetadata, challenge ssh.KeyboardInteractiveChallenge) (*ssh.Permissions, error) {
-			if !auth.AllowAnonymous() {
-				return nil, errors.New("public key authentication required")
+			err := auth.CheckBans(conn.RemoteAddr(), nil, sanitize.Data(string(conn.ClientVersion()), 64))
+			if err != nil {
+				return nil, err
+			}
+			if auth.AcceptPassphrase() {
+				var answers []string
+				answers, err = challenge("", "", []string{"Passphrase required to connect: "}, []bool{true})
+				if err == nil {
+					if len(answers) != 1 {
+						err = errors.New("didn't get passphrase")
+					} else {
+						err = auth.CheckPassphrase(answers[0])
+						if err != nil {
+							auth.BanAddr(conn.RemoteAddr(), time.Second*2)
+						}
+					}
+				}
+			} else if !auth.AllowAnonymous() {
+				err = errors.New("public key authentication required")
 			}
-			err := auth.Check(conn.RemoteAddr(), nil, sanitize.Data(string(conn.ClientVersion()), 64))
 			return nil, err
 		},
 	}

sshd/client.go

@@ -30,9 +30,24 @@ func NewClientConfig(name string) *ssh.ClientConfig {
 	}
 }
 
+func NewClientConfigWithKey(name string, key ssh.Signer) *ssh.ClientConfig {
+	return &ssh.ClientConfig{
+		User:            name,
+		Auth:            []ssh.AuthMethod{ssh.PublicKeys(key)},
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+	}
+}
+
 // ConnectShell makes a barebones SSH client session, used for testing.
 func ConnectShell(host string, name string, handler func(r io.Reader, w io.WriteCloser) error) error {
-	config := NewClientConfig(name)
+	return connectShell(host, NewClientConfig(name), handler)
+}
+
+func ConnectShellWithKey(host string, name string, key ssh.Signer, handler func(r io.Reader, w io.WriteCloser) error) error {
+	return connectShell(host, NewClientConfigWithKey(name, key), handler)
+}
+
+func connectShell(host string, config *ssh.ClientConfig, handler func(r io.Reader, w io.WriteCloser) error) error {
 	conn, err := ssh.Dial("tcp", host, config)
 	if err != nil {
 		return err

sshd/client_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net"
 	"testing"
+	"time"
 
 	"golang.org/x/crypto/ssh"
 )
@@ -15,9 +16,19 @@ type RejectAuth struct{}
 func (a RejectAuth) AllowAnonymous() bool {
 	return false
 }
-func (a RejectAuth) Check(net.Addr, ssh.PublicKey, string) error {
+func (a RejectAuth) AcceptPassphrase() bool {
+	return false
+}
+func (a RejectAuth) CheckBans(addr net.Addr, key ssh.PublicKey, clientVersion string) error {
 	return errRejectAuth
 }
+func (a RejectAuth) CheckPublicKey(ssh.PublicKey) error {
+	return errRejectAuth
+}
+func (a RejectAuth) CheckPassphrase(string) error {
+	return errRejectAuth
+}
+func (a RejectAuth) BanAddr(net.Addr, time.Duration) {}
 
 func TestClientReject(t *testing.T) {
 	signer, err := NewRandomSigner(512)

sshd/net_test.go

@@ -25,7 +25,7 @@ func TestServerInit(t *testing.T) {
 }
 
 func TestServeTerminals(t *testing.T) {
-	signer, err := NewRandomSigner(512)
+	signer, err := NewRandomSigner(1024)
 	if err != nil {
 		t.Fatal(err)
 	}

sshd/terminal.go

@@ -167,7 +167,9 @@ func (t *Terminal) Close() error {
 	var err error
 	t.closeOnce.Do(func() {
 		close(t.done)
-		t.Channel.Close()
+		if err := t.Channel.Close(); err != nil {
+			logger.Printf("[%s] Failed to close terminal channel: %s", t.Conn.RemoteAddr(), err)
+		}
 		err = t.Conn.Close()
 	})
 	return err

sshd/terminal/terminal.go

@@ -264,6 +264,10 @@ func (t *Terminal) moveCursorToPos(pos int) {
 		return
 	}
 
+	if pos > len(t.line) {
+		pos = len(t.line)
+	}
+
 	x := visualLength(t.prompt) + visualLength(t.line[:pos])
 	y := x / t.termWidth
 	x = x % t.termWidth