Merge branch 'verification'

Fixes #160
Fixes #161

13 files changed, 741 insertions, 100 deletions

diff --git a/config/config.go b/config/config.go
index a958b1c..03e186f 100644
--- a/config/config.go
+++ b/config/config.go
@@ -62,7 +62,8 @@ type Config struct {
 	RoomCacheSize int   `yaml:"room_cache_size"`
 	RoomCacheAge  int64 `yaml:"room_cache_age"`
 
-	NotifySound bool `yaml:"notify_sound"`
+	NotifySound        bool `yaml:"notify_sound"`
+	SendToVerifiedOnly bool `yaml:"send_to_verified_only"`
 
 	Dir          string `yaml:"-"`
 	DataDir      string `yaml:"data_dir"`
@@ -96,7 +97,8 @@ func NewConfig(configDir, dataDir, cacheDir, downloadDir string) *Config {
 		RoomCacheSize: 32,
 		RoomCacheAge:  1 * 60,
 
-		NotifySound: true,
+		NotifySound:        true,
+		SendToVerifiedOnly: false,
 	}
 }
 
diff --git a/go.mod b/go.mod
index 38c02d9..357fb8c 100644
--- a/go.mod
+++ b/go.mod
@@ -23,7 +23,7 @@ require (
 	golang.org/x/net v0.0.0-20200602114024-627f9648deb9
 	gopkg.in/toast.v1 v1.0.0-20180812000517-0a84660828b2
 	gopkg.in/yaml.v2 v2.3.0
-	maunium.net/go/mautrix v0.5.5
+	maunium.net/go/mautrix v0.7.0-rc.1
 	maunium.net/go/mauview v0.1.1
 	maunium.net/go/tcell v0.2.0
 )
diff --git a/go.sum b/go.sum
index e4ebe5d..f3bd493 100644
--- a/go.sum
+++ b/go.sum
@@ -1,9 +1,11 @@
+github.com/PuerkitoBio/goquery v1.5.1/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc=
 github.com/alecthomas/assert v0.0.0-20170929043011-405dbfeb8e38/go.mod h1:r7bzyVFMNntcxPZXK3/+KdruV1H5KSlyVY0gc+NgInI=
 github.com/alecthomas/chroma v0.7.3 h1:NfdAERMy+esYQs8OXk0I868/qDxxCEo7FMz1WIqMAeI=
 github.com/alecthomas/chroma v0.7.3/go.mod h1:sko8vR34/90zvl5QdcUdvzL3J8NKjAUx9va9jPuFNoM=
 github.com/alecthomas/colour v0.0.0-20160524082231-60882d9e2721/go.mod h1:QO9JBoKquHd+jz9nshCh40fOfO+JzsoXy8qTHF68zU0=
 github.com/alecthomas/kong v0.2.4/go.mod h1:kQOmtJgV+Lb4aj+I2LEn40cbtawdWJ9Y8QLq+lElKxE=
 github.com/alecthomas/repr v0.0.0-20180818092828-117648cd9897/go.mod h1:xTS7Pm1pD1mvyM075QCDSRqH6qRLXylzS24ZTpRiSzQ=
+github.com/andybalholm/cascadia v1.1.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
 github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964 h1:y5HC9v93H5EPKqaS1UYVg1uYah5Xf51mBfIoWehClUQ=
 github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964/go.mod h1:Xd9hchkHSWYkEqJwUGisez3G1QY8Ryz0sdWrLPMGjLk=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -28,6 +30,13 @@ github.com/mattn/go-colorable v0.1.6/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mattn/go-sqlite3 v1.14.0/go.mod h1:JIl7NbARA7phWnGvh0LKTyg7S9BA+6gx71ShQilpsus=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725145808-be3336827da7 h1:w5IiIpetgAwalLPFkxiVbxBXJtcB9zLhoGLkyouQb4k=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725145808-be3336827da7/go.mod h1:Va/74MijqaS0DQ3aUqxmFO54/PMfr1LVsCOcGRHbYmo=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725165923-cae799088b7e h1:K8D+9n29FP1Utrv2joUhjcuDL1zC+Qq9rEFdV5kPgTQ=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725165923-cae799088b7e/go.mod h1:Va/74MijqaS0DQ3aUqxmFO54/PMfr1LVsCOcGRHbYmo=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725175335-dd3f90913c4d h1:tsCIy4CvvAeFEoBhet7zGoZXc+lr/e2YogoPaEGdMN8=
+github.com/nikofil/mautrix-go v0.5.2-0.20200725175335-dd3f90913c4d/go.mod h1:Va/74MijqaS0DQ3aUqxmFO54/PMfr1LVsCOcGRHbYmo=
 github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d/go.mod h1:YUTz3bUH2ZwIWBy3CJBeOBEugqcmXREj14T+iG/4k4U=
 github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 h1:q2e307iGHPdTGp0hoxKjt1H5pDo6utceo3dQVK3I5XQ=
 github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5/go.mod h1:jvVRKCrJTQWu0XVbaOlby/2lO20uSCHEMzzplHXte1o=
@@ -70,7 +79,10 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20200430140353-33d19683fad8 h1:6WW6V3x1P/jokJBpRQYUJnMHRP6isStQwCozxnU7XQw=
 golang.org/x/image v0.0.0-20200430140353-33d19683fad8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200602114024-627f9648deb9 h1:pNX+40auqi2JqRfOP1akLGtYcn15TUbkhwuCO3foqqM=
 golang.org/x/net v0.0.0-20200602114024-627f9648deb9/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -100,6 +112,8 @@ maunium.net/go/mautrix v0.5.3 h1:Lu4PGZvKZwhXmdDnBdLwmiImNM3jNGwJI9Sk78P+Gys=
 maunium.net/go/mautrix v0.5.3/go.mod h1:LnkFnB1yjCbb8V+upoEHDGvI/F38NHSTWYCe2RRJgSY=
 maunium.net/go/mautrix v0.5.5 h1:e0Pql1FdxoNUudx2oXo1gZHMrqIh5MC72cdXEPIrYLA=
 maunium.net/go/mautrix v0.5.5/go.mod h1:FLbMANzwqlsX2Fgm7SDe+E4I3wSa4UxJRKqS5wGkCwA=
+maunium.net/go/mautrix v0.7.0-rc.1 h1:DT7bNR9q+HlFs5Oo9IqmtWPkE4WPKZdRfIWRtlqkXtM=
+maunium.net/go/mautrix v0.7.0-rc.1/go.mod h1:Va/74MijqaS0DQ3aUqxmFO54/PMfr1LVsCOcGRHbYmo=
 maunium.net/go/mauview v0.1.1 h1:wfTXyPx3LGAGpTskh+UbBv/QItUWnEpaneHmywoYnfY=
 maunium.net/go/mauview v0.1.1/go.mod h1:3QBUiuLct9moP1LgDhCGIg0Ovxn38Bd2sGndnUOuj4o=
 maunium.net/go/tcell v0.2.0 h1:1Q0kN3wCOGAIGu1r3QHADsjSUOPDylKREvCv3EzJpVg=
diff --git a/matrix/crypto.go b/matrix/crypto.go
index 158a1f2..c549e8a 100644
--- a/matrix/crypto.go
+++ b/matrix/crypto.go
@@ -55,7 +55,9 @@ func (c *Container) initCrypto() error {
 	if err != nil {
 		return errors.Wrap(err, "failed to open crypto store")
 	}
-	c.crypto = crypto.NewOlmMachine(c.client, cryptoLogger{}, cryptoStore, c.config.Rooms)
+	crypt := crypto.NewOlmMachine(c.client, cryptoLogger{}, cryptoStore, c.config.Rooms)
+	crypt.AllowUnverifiedDevices = !c.config.SendToVerifiedOnly
+	c.crypto = crypt
 	err = c.crypto.Load()
 	if err != nil {
 		return errors.Wrap(err, "failed to create olm machine")
diff --git a/matrix/matrix.go b/matrix/matrix.go
index b07fa82..f7f308b 100644
--- a/matrix/matrix.go
+++ b/matrix/matrix.go
@@ -162,6 +162,8 @@ func (c *Container) PasswordLogin(user, password string) error {
 		},
 		Password:                 password,
 		InitialDeviceDisplayName: "gomuks",
+
+		StoreCredentials: true,
 	})
 	if err != nil {
 		return err
@@ -171,8 +173,6 @@ func (c *Container) PasswordLogin(user, password string) error {
 }
 
 func (c *Container) finishLogin(resp *mautrix.RespLogin) {
-	c.client.SetCredentials(resp.UserID, resp.AccessToken)
-	c.client.DeviceID = resp.DeviceID
 	c.config.UserID = resp.UserID
 	c.config.DeviceID = resp.DeviceID
 	c.config.AccessToken = resp.AccessToken
@@ -218,6 +218,8 @@ func (c *Container) SingleSignOn() error {
 			Type:                     "m.login.token",
 			Token:                    loginToken,
 			InitialDeviceDisplayName: "gomuks",
+
+			StoreCredentials: true,
 		})
 		if err != nil {
 			respondHTML(w, http.StatusForbidden, err.Error())
diff --git a/matrix/rooms/roomcache.go b/matrix/rooms/roomcache.go
index 5af0c5b..168278b 100644
--- a/matrix/rooms/roomcache.go
+++ b/matrix/rooms/roomcache.go
@@ -73,6 +73,19 @@ func (cache *RoomCache) IsEncrypted(roomID id.RoomID) bool {
 	return room != nil && room.Encrypted
 }
 
+func (cache *RoomCache) GetEncryptionEvent(roomID id.RoomID) *event.EncryptionEventContent {
+	room := cache.Get(roomID)
+	evt := room.GetStateEvent(event.StateEncryption, "")
+	if evt == nil {
+		return nil
+	}
+	content, ok := evt.Content.Parsed.(*event.EncryptionEventContent)
+	if !ok {
+		return nil
+	}
+	return content
+}
+
 func (cache *RoomCache) FindSharedRooms(userID id.UserID) (shared []id.RoomID) {
 	// FIXME this disables unloading so TouchNode wouldn't try to double-lock
 	cache.DisableUnloading()
diff --git a/ui/command-processor.go b/ui/command-processor.go
index b8f41a2..514d67b 100644
--- a/ui/command-processor.go
+++ b/ui/command-processor.go
@@ -20,6 +20,8 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/mattn/go-runewidth"
+
 	"maunium.net/go/gomuks/config"
 	"maunium.net/go/gomuks/debug"
 	"maunium.net/go/gomuks/interface"
@@ -45,6 +47,8 @@ type Command struct {
 	OrigText    string
 }
 
+type CommandAutocomplete Command
+
 func (cmd *Command) Reply(message string, args ...interface{}) {
 	cmd.Room.AddServiceMessage(fmt.Sprintf(message, args...))
 	cmd.UI.Render()
@@ -60,12 +64,15 @@ func (alias *Alias) Process(cmd *Command) *Command {
 }
 
 type CommandHandler func(cmd *Command)
+type CommandAutocompleter func(cmd *CommandAutocomplete) (completions []string, newText string)
 
 type CommandProcessor struct {
 	gomuksPointerContainer
 
 	aliases  map[string]*Alias
 	commands map[string]CommandHandler
+
+	autocompleters map[string]CommandAutocompleter
 }
 
 func NewCommandProcessor(parent *MainView) *CommandProcessor {
@@ -97,6 +104,12 @@ func NewCommandProcessor(parent *MainView) *CommandProcessor {
 			"dl":         {"download"},
 			"o":          {"open"},
 		},
+		autocompleters: map[string]CommandAutocompleter{
+			"devices":  autocompleteDevice,
+			"device":   autocompleteDevice,
+			"verify":   autocompleteDevice,
+			"unverify": autocompleteDevice,
+		},
 		commands: map[string]CommandHandler{
 			"unknown-command": cmdUnknownCommand,
 
@@ -139,7 +152,13 @@ func NewCommandProcessor(parent *MainView) *CommandProcessor {
 			"cprof":      cmdCPUProfile,
 			"trace":      cmdTrace,
 
-			"fingerprint": cmdFingerprint,
+			"fingerprint":   cmdFingerprint,
+			"devices":       cmdDevices,
+			"verify":        cmdVerify,
+			"device":        cmdDevice,
+			"unverify":      cmdUnverify,
+			"blacklist":     cmdBlacklist,
+			"reset-session": cmdResetSession,
 		},
 	}
 }
@@ -169,6 +188,47 @@ func (ch *CommandProcessor) ParseCommand(roomView *RoomView, text string) *Comma
 	}
 }
 
+func (ch *CommandProcessor) Autocomplete(roomView *RoomView, text string, cursorOffset int) ([]string, string, bool) {
+	var completions []string
+	if cmd := (*CommandAutocomplete)(ch.ParseCommand(roomView, text)); cmd == nil {
+		return completions, text, false
+	} else if handler, ok := ch.autocompleters[cmd.Command]; !ok {
+		return completions, text, false
+	} else if cursorOffset != runewidth.StringWidth(text) {
+		return completions, text, false
+	} else {
+		completions, newText := handler(cmd)
+		if newText == "" {
+			newText = text
+		}
+		return completions, newText, true
+	}
+}
+
+func (ch *CommandProcessor) AutocompleteCommand(word string) (completions []string) {
+	if word[0] != '/' {
+		return
+	}
+	word = word[1:]
+	for alias := range ch.aliases {
+		if alias == word {
+			return []string{"/" + alias}
+		}
+		if strings.HasPrefix(alias, word) {
+			completions = append(completions, "/"+alias)
+		}
+	}
+	for command := range ch.commands {
+		if command == word {
+			return []string{"/" + command}
+		}
+		if strings.HasPrefix(command, word) {
+			completions = append(completions, "/"+command)
+		}
+	}
+	return
+}
+
 func (ch *CommandProcessor) HandleCommand(cmd *Command) {
 	defer debug.Recover()
 	if cmd == nil {
diff --git a/ui/commands.go b/ui/commands.go
index 49bff0f..9d38396 100644
--- a/ui/commands.go
+++ b/ui/commands.go
@@ -440,7 +440,7 @@ func cmdHelp(cmd *Command) {
 /logout         - Log out of Matrix.
 /toggle <thing> - Temporary command to toggle various UI features.
 
-Things: rooms, users, baremessages, images, typingnotif
+Things: rooms, users, baremessages, images, typingnotif, unverified
 
 # Sending special messages
 /me <message>        - Send an emote message.
@@ -449,7 +449,18 @@ Things: rooms, users, baremessages, images, typingnotif
 /rainbowme <message> - Send rainbow text in an emote.
 /reply [text]        - Reply to the selected message.
 /react <reaction>    - React to the selected message.
-/redact [reason]    - Redact the selected message.
+/redact [reason]     - Redact the selected message.
+
+# Encryption
+/fingerprint - View the fingerprint of your device.
+
+/devices <user id>               - View the device list of a user.
+/device <user id> <device id>    - Show info about a specific device.
+/unverify <user id> <device id>  - Un-verify a device.
+/blacklist <user id> <device id> - Blacklist a device.
+/verify <user id> <device id> [fingerprint]
+    - Verify a device. If the fingerprint is not provided,
+      interactive emoji verification will be started.
 
 # Rooms
 /pm <user id> <...>   - Create a private chat with the given user(s).
@@ -710,6 +721,7 @@ var toggleMsg = map[string]ToggleMessage{
 	"markdown":      SimpleToggleMessage("markdown input"),
 	"downloads":     SimpleToggleMessage("automatic downloads"),
 	"notifications": SimpleToggleMessage("desktop notifications"),
+	"unverified":    SimpleToggleMessage("sending messages to unverified devices"),
 }
 
 func makeUsage() string {
@@ -750,6 +762,8 @@ func cmdToggle(cmd *Command) {
 			val = &cmd.Config.Preferences.DisableDownloads
 		case "notifications":
 			val = &cmd.Config.Preferences.DisableNotifications
+		case "unverified":
+			val = &cmd.Config.SendToVerifiedOnly
 		default:
 			cmd.Reply("Unknown toggle %s. Use /toggle without arguments for a list of togglable things.", thing)
 			return
diff --git a/ui/crypto-commands.go b/ui/crypto-commands.go
new file mode 100644
index 0000000..232f508
--- /dev/null
+++ b/ui/crypto-commands.go
@@ -0,0 +1,231 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2020 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// +build cgo
+
+package ui
+
+import (
+	"fmt"
+	"strings"
+	"time"
+	"unicode"
+
+	"maunium.net/go/mautrix/crypto"
+	"maunium.net/go/mautrix/id"
+)
+
+func autocompleteDeviceUserID(cmd *CommandAutocomplete) (completions []string, newText string) {
+	userCompletions := cmd.Room.AutocompleteUser(cmd.Args[0])
+	if len(userCompletions) == 1 {
+		newText = fmt.Sprintf("/%s %s ", cmd.OrigCommand, userCompletions[0].id)
+	} else {
+		completions = make([]string, len(userCompletions))
+		for i, completion := range userCompletions {
+			completions[i] = completion.id
+		}
+	}
+	return
+}
+
+func autocompleteDeviceDeviceID(cmd *CommandAutocomplete) (completions []string, newText string) {
+	mach := cmd.Matrix.Crypto().(*crypto.OlmMachine)
+	devices, err := mach.CryptoStore.GetDevices(id.UserID(cmd.Args[0]))
+	if len(devices) == 0 || err != nil {
+		return
+	}
+	var completedDeviceID id.DeviceID
+	if len(cmd.Args) > 1 {
+		existingID := strings.ToUpper(cmd.Args[1])
+		for _, device := range devices {
+			deviceIDStr := string(device.DeviceID)
+			if deviceIDStr == existingID {
+				// We don't want to do any autocompletion if there's already a full device ID there.
+				return []string{}, ""
+			} else if strings.HasPrefix(strings.ToUpper(device.Name), existingID) || strings.HasPrefix(deviceIDStr, existingID) {
+				completedDeviceID = device.DeviceID
+				completions = append(completions, fmt.Sprintf("%s (%s)", device.DeviceID, device.Name))
+			}
+		}
+	} else {
+		completions = make([]string, len(devices))
+		i := 0
+		for _, device := range devices {
+			completedDeviceID = device.DeviceID
+			completions[i] = fmt.Sprintf("%s (%s)", device.DeviceID, device.Name)
+			i++
+		}
+	}
+	if len(completions) == 1 {
+		newText = fmt.Sprintf("/%s %s %s ", cmd.OrigCommand, cmd.Args[0], completedDeviceID)
+	}
+	return
+}
+
+func autocompleteDevice(cmd *CommandAutocomplete) ([]string, string) {
+	if len(cmd.Args) == 0 {
+		return []string{}, ""
+	} else if len(cmd.Args) == 1 && !unicode.IsSpace(rune(cmd.RawArgs[len(cmd.RawArgs)-1])) {
+		return autocompleteDeviceUserID(cmd)
+	} else if cmd.Command != "devices" {
+		return autocompleteDeviceDeviceID(cmd)
+	}
+	return []string{}, ""
+}
+
+func getDevice(cmd *Command) *crypto.DeviceIdentity {
+	if len(cmd.Args) < 2 {
+		cmd.Reply("Usage: /%s <user id> <device id> [fingerprint]", cmd.Command)
+		return nil
+	}
+	mach := cmd.Matrix.Crypto().(*crypto.OlmMachine)
+	device, err := mach.GetOrFetchDevice(id.UserID(cmd.Args[0]), id.DeviceID(cmd.Args[1]))
+	if err != nil {
+		cmd.Reply("Failed to get device: %v", err)
+		return nil
+	}
+	return device
+}
+
+func putDevice(cmd *Command, device *crypto.DeviceIdentity, action string) {
+	mach := cmd.Matrix.Crypto().(*crypto.OlmMachine)
+	err := mach.CryptoStore.PutDevice(device.UserID, device)
+	if err != nil {
+		cmd.Reply("Failed to save device: %v", err)
+	} else {
+		cmd.Reply("Successfully %s %s/%s (%s)", action, device.UserID, device.DeviceID, device.Name)
+	}
+	mach.OnDevicesChanged(device.UserID)
+}
+
+func cmdDevices(cmd *Command) {
+	if len(cmd.Args) == 0 {
+		cmd.Reply("Usage: /devices <user id>")
+		return
+	}
+	userID := id.UserID(cmd.Args[0])
+	mach := cmd.Matrix.Crypto().(*crypto.OlmMachine)
+	devices, err := mach.CryptoStore.GetDevices(userID)
+	if err != nil {
+		cmd.Reply("Failed to get device list: %v", err)
+	}
+	if len(devices) == 0 {
+		cmd.Reply("Fetching device list from server...")
+		devices = mach.LoadDevices(userID)
+	}
+	if len(devices) == 0 {
+		cmd.Reply("No devices found for %s", userID)
+		return
+	}
+	var buf strings.Builder
+	for _, device := range devices {
+		_, _ = fmt.Fprintf(&buf, "%s (%s) - %s\n    Fingerprint: %s\n", device.DeviceID, device.Name, device.Trust.String(), device.Fingerprint())
+	}
+	resp := buf.String()
+	cmd.Reply("%s", resp[:len(resp)-1])
+}
+
+func cmdDevice(cmd *Command) {
+	device := getDevice(cmd)
+	if device == nil {
+		return
+	}
+	deviceType := "Device"
+	if device.Deleted {
+		deviceType = "Deleted device"
+	}
+	cmd.Reply("%s %s of %s\nFingerprint: %s\nIdentity key: %s\nDevice name: %s\nTrust state: %s",
+		deviceType, device.DeviceID, device.UserID,
+		device.Fingerprint(), device.IdentityKey,
+		device.Name, device.Trust.String())
+}
+
+func cmdVerify(cmd *Command) {
+	device := getDevice(cmd)
+	if device == nil {
+		return
+	}
+	if device.Trust == crypto.TrustStateVerified {
+		cmd.Reply("That device is already verified")
+		return
+	}
+	if len(cmd.Args) == 2 {
+		mach := cmd.Matrix.Crypto().(*crypto.OlmMachine)
+		mach.DefaultSASTimeout = 120 * time.Second
+		modal := NewVerificationModal(cmd.MainView, device, mach.DefaultSASTimeout)
+		cmd.MainView.ShowModal(modal)
+		_, err := mach.NewSimpleSASVerificationWith(device, modal)
+		if err != nil {
+			cmd.Reply("Failed to start interactive verification: %v", err)
+			return
+		}
+	} else {
+		fingerprint := strings.Join(cmd.Args[2:], "")
+		if string(device.SigningKey) != fingerprint {
+			cmd.Reply("Mismatching fingerprint")
+			return
+		}
+		action := "verified"
+		if device.Trust == crypto.TrustStateBlacklisted {
+			action = "unblacklisted and verified"
+		}
+		device.Trust = crypto.TrustStateVerified
+		putDevice(cmd, device, action)
+	}
+}
+
+func cmdUnverify(cmd *Command) {
+	device := getDevice(cmd)
+	if device == nil {
+		return
+	}
+	if device.Trust == crypto.TrustStateUnset {
+		cmd.Reply("That device is already not verified")
+		return
+	}
+	action := "unverified"
+	if device.Trust == crypto.TrustStateBlacklisted {
+		action = "unblacklisted"
+	}
+	device.Trust = crypto.TrustStateUnset
+	putDevice(cmd, device, action)
+}
+
+func cmdBlacklist(cmd *Command) {
+	device := getDevice(cmd)
+	if device == nil {
+		return
+	}
+	if device.Trust == crypto.TrustStateBlacklisted {
+		cmd.Reply("That device is already blacklisted")
+		return
+	}
+	action := "blacklisted"
+	if device.Trust == crypto.TrustStateVerified {
+		action = "unverified and blacklisted"
+	}
+	device.Trust = crypto.TrustStateBlacklisted
+	putDevice(cmd, device, action)
+}
+
+func cmdResetSession(cmd *Command) {
+	err := cmd.Matrix.Crypto().(*crypto.OlmMachine).CryptoStore.RemoveOutboundGroupSession(cmd.Room.Room.ID)
+	if err != nil {
+		cmd.Reply("Failed to remove outbound group session: %v", err)
+	} else {
+		cmd.Reply("Removed outbound group session for this room")
+	}
+}
diff --git a/ui/no-crypto-commands.go b/ui/no-crypto-commands.go
new file mode 100644
index 0000000..dae85b4
--- /dev/null
+++ b/ui/no-crypto-commands.go
@@ -0,0 +1,36 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2020 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// +build !cgo
+
+package ui
+
+func autocompleteDevice(cmd *CommandAutocomplete) ([]string, string) {
+	return []string{}, ""
+}
+
+func cmdNoCrypto(cmd *Command) {
+	cmd.Reply("This gomuks was built without encryption support")
+}
+
+var (
+	cmdDevices = cmdNoCrypto
+	cmdDevice = cmdNoCrypto
+	cmdVerify = cmdNoCrypto
+	cmdUnverify = cmdNoCrypto
+	cmdBlacklist = cmdNoCrypto
+	cmdResetSession = cmdNoCrypto
+)
diff --git a/ui/room-view.go b/ui/room-view.go
index dbdaccc..225e0a9 100644
--- a/ui/room-view.go
+++ b/ui/room-view.go
@@ -22,15 +22,18 @@ import (
 	"sort"
 	"strings"
 	"time"
+	"unicode"
 
 	"github.com/kyokomi/emoji"
 	"github.com/mattn/go-runewidth"
 	"github.com/zyedidia/clipboard"
 
-	"maunium.net/go/mautrix/crypto/attachment"
 	"maunium.net/go/mauview"
 	"maunium.net/go/tcell"
 
+	"maunium.net/go/gomuks/lib/util"
+	"maunium.net/go/mautrix/crypto/attachment"
+
 	"maunium.net/go/mautrix"
 	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
@@ -39,7 +42,6 @@ import (
 	"maunium.net/go/gomuks/debug"
 	"maunium.net/go/gomuks/interface"
 	"maunium.net/go/gomuks/lib/open"
-	"maunium.net/go/gomuks/lib/util"
 	"maunium.net/go/gomuks/matrix/muksevt"
 	"maunium.net/go/gomuks/matrix/rooms"
 	"maunium.net/go/gomuks/ui/messages"
@@ -420,65 +422,6 @@ func (view *RoomView) SetTyping(users []id.UserID) {
 	}
 }
 
-type completion struct {
-	displayName string
-	id          string
-}
-
-func (view *RoomView) autocompleteUser(existingText string) (completions []completion) {
-	textWithoutPrefix := strings.TrimPrefix(existingText, "@")
-	for userID, user := range view.Room.GetMembers() {
-		if user.Displayname == textWithoutPrefix || string(userID) == existingText {
-			// Exact match, return that.
-			return []completion{{user.Displayname, string(userID)}}
-		}
-
-		if strings.HasPrefix(user.Displayname, textWithoutPrefix) || strings.HasPrefix(string(userID), existingText) {
-			completions = append(completions, completion{user.Displayname, string(userID)})
-		}
-	}
-	return
-}
-
-func (view *RoomView) autocompleteRoom(existingText string) (completions []completion) {
-	for _, room := range view.parent.rooms {
-		alias := string(room.Room.GetCanonicalAlias())
-		if alias == existingText {
-			// Exact match, return that.
-			return []completion{{alias, string(room.Room.ID)}}
-		}
-		if strings.HasPrefix(alias, existingText) {
-			completions = append(completions, completion{alias, string(room.Room.ID)})
-			continue
-		}
-	}
-	return
-}
-
-func (view *RoomView) autocompleteEmoji(word string) (completions []string) {
-	if len(word) == 0 || word[0] != ':' {
-		return
-	}
-	var valueCompletion1 string
-	var manyValues bool
-	for name, value := range emoji.CodeMap() {
-		if name == word {
-			return []string{value}
-		} else if strings.HasPrefix(name, word) {
-			completions = append(completions, name)
-			if valueCompletion1 == "" {
-				valueCompletion1 = value
-			} else if valueCompletion1 != value {
-				manyValues = true
-			}
-		}
-	}
-	if !manyValues && len(completions) > 0 {
-		return []string{emoji.CodeMap()[completions[0]]}
-	}
-	return
-}
-
 func (view *RoomView) SetEditing(evt *muksevt.Event) {
 	if evt == nil {
 		view.editing = nil
@@ -584,23 +527,90 @@ func (view *RoomView) SelectPrevious() {
 	}
 }
 
-func (view *RoomView) InputTabComplete(text string, cursorOffset int) {
-	debug.Print("Tab completing", cursorOffset, text)
-	str := runewidth.Truncate(text, cursorOffset, "")
-	word := findWordToTabComplete(str)
-	startIndex := len(str) - len(word)
+type completion struct {
+	displayName string
+	id          string
+}
 
-	var strCompletions []string
-	var strCompletion string
+func (view *RoomView) AutocompleteUser(existingText string) (completions []completion) {
+	textWithoutPrefix := strings.TrimPrefix(existingText, "@")
+	for userID, user := range view.Room.GetMembers() {
+		if user.Displayname == textWithoutPrefix || string(userID) == existingText {
+			// Exact match, return that.
+			return []completion{{user.Displayname, string(userID)}}
+		}
+
+		if strings.HasPrefix(user.Displayname, textWithoutPrefix) || strings.HasPrefix(string(userID), existingText) {
+			completions = append(completions, completion{user.Displayname, string(userID)})
+		}
+	}
+	return
+}
 
-	completions := view.autocompleteUser(word)
-	completions = append(completions, view.autocompleteRoom(word)...)
+func (view *RoomView) AutocompleteRoom(existingText string) (completions []completion) {
+	for _, room := range view.parent.rooms {
+		alias := string(room.Room.GetCanonicalAlias())
+		if alias == existingText {
+			// Exact match, return that.
+			return []completion{{alias, string(room.Room.ID)}}
+		}
+		if strings.HasPrefix(alias, existingText) {
+			completions = append(completions, completion{alias, string(room.Room.ID)})
+			continue
+		}
+	}
+	return
+}
+
+func (view *RoomView) AutocompleteEmoji(word string) (completions []string) {
+	if word[0] != ':' {
+		return
+	}
+	var valueCompletion1 string
+	var manyValues bool
+	for name, value := range emoji.CodeMap() {
+		if name == word {
+			return []string{value}
+		} else if strings.HasPrefix(name, word) {
+			completions = append(completions, name)
+			if valueCompletion1 == "" {
+				valueCompletion1 = value
+			} else if valueCompletion1 != value {
+				manyValues = true
+			}
+		}
+	}
+	if !manyValues && len(completions) > 0 {
+		return []string{emoji.CodeMap()[completions[0]]}
+	}
+	return
+}
+
+func findWordToTabComplete(text string) string {
+	output := ""
+	runes := []rune(text)
+	for i := len(runes) - 1; i >= 0; i-- {
+		if unicode.IsSpace(runes[i]) {
+			break
+		}
+		output = string(runes[i]) + output
+	}
+	return output
+}
+
+func (view *RoomView) defaultAutocomplete(word string, startIndex int) (strCompletions []string, strCompletion string) {
+	if len(word) == 0 {
+		return []string{}, ""
+	}
+
+	completions := view.AutocompleteUser(word)
+	completions = append(completions, view.AutocompleteRoom(word)...)
 
 	if len(completions) == 1 {
 		completion := completions[0]
 		strCompletion = fmt.Sprintf("[%s](https://matrix.to/#/%s)", completion.displayName, completion.id)
-		if startIndex == 0 {
-			strCompletion = strCompletion + ": "
+		if startIndex == 0 && completion.id[0] == '@' {
+			strCompletion = strCompletion + ":"
 		}
 	} else if len(completions) > 1 {
 		for _, completion := range completions {
@@ -608,18 +618,42 @@ func (view *RoomView) InputTabComplete(text string, cursorOffset int) {
 		}
 	}
 
-	strCompletions = append(strCompletions, view.autocompleteEmoji(word)...)
+	strCompletions = append(strCompletions, view.parent.cmdProcessor.AutocompleteCommand(word)...)
+	strCompletions = append(strCompletions, view.AutocompleteEmoji(word)...)
+
+	return
+}
+
+func (view *RoomView) InputTabComplete(text string, cursorOffset int) {
+	if len(text) == 0 {
+		return
+	}
+
+	str := runewidth.Truncate(text, cursorOffset, "")
+	word := findWordToTabComplete(str)
+	startIndex := len(str) - len(word)
+
+	var strCompletion string
+
+	strCompletions, newText, ok := view.parent.cmdProcessor.Autocomplete(view, text, cursorOffset)
+	if !ok {
+		strCompletions, strCompletion = view.defaultAutocomplete(word, startIndex)
+	}
 
 	if len(strCompletions) > 0 {
 		strCompletion = util.LongestCommonPrefix(strCompletions)
 		sort.Sort(sort.StringSlice(strCompletions))
 	}
+	if len(strCompletion) > 0 && len(strCompletions) < 2 {
+		strCompletion += " "
+		strCompletions = []string{}
+	}
 
-	if len(strCompletion) > 0 {
-		text = str[0:startIndex] + strCompletion + text[len(str):]
+	if len(strCompletion) > 0 && newText == text {
+		newText = str[0:startIndex] + strCompletion + text[len(str):]
 	}
 
-	view.input.SetTextAndMoveCursor(text)
+	view.input.SetTextAndMoveCursor(newText)
 	view.SetCompletions(strCompletions)
 }
 
diff --git a/ui/verification-modal.go b/ui/verification-modal.go
new file mode 100644
index 0000000..bc529c9
--- /dev/null
+++ b/ui/verification-modal.go
@@ -0,0 +1,245 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2020 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// +build cgo
+
+package ui
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"maunium.net/go/mauview"
+	"maunium.net/go/tcell"
+
+	"maunium.net/go/gomuks/debug"
+	"maunium.net/go/mautrix/crypto"
+	"maunium.net/go/mautrix/event"
+)
+
+type EmojiView struct {
+	mauview.SimpleEventHandler
+	Data crypto.SASData
+}
+
+func (e *EmojiView) Draw(screen mauview.Screen) {
+	if e.Data == nil {
+		return
+	}
+	switch e.Data.Type() {
+	case event.SASEmoji:
+		width := 10
+		for i, emoji := range e.Data.(crypto.EmojiSASData) {
+			x := i*width + i
+			y := 0
+			if i >= 4 {
+				x = (i-4)*width + i
+				y = 2
+			}
+			mauview.Print(screen, string(emoji.Emoji), x, y, width, mauview.AlignCenter, tcell.ColorDefault)
+			mauview.Print(screen, emoji.Description, x, y+1, width, mauview.AlignCenter, tcell.ColorDefault)
+		}
+	case event.SASDecimal:
+		maxWidth := 43
+		for i, number := range e.Data.(crypto.DecimalSASData) {
+			mauview.Print(screen, strconv.FormatUint(uint64(number), 10), 0, i, maxWidth, mauview.AlignCenter, tcell.ColorDefault)
+		}
+	}
+}
+
+type VerificationModal struct {
+	mauview.Component
+
+	device *crypto.DeviceIdentity
+
+	container *mauview.Box
+
+	waitingBar *mauview.ProgressBar
+	infoText   *mauview.TextView
+	emojiText  *EmojiView
+	inputBar   *mauview.InputField
+
+	progress    int
+	progressMax int
+	stopWaiting chan struct{}
+	confirmChan chan bool
+	done        bool
+
+	parent *MainView
+}
+
+func NewVerificationModal(mainView *MainView, device *crypto.DeviceIdentity, timeout time.Duration) *VerificationModal {
+	vm := &VerificationModal{
+		parent:      mainView,
+		device:      device,
+		stopWaiting: make(chan struct{}),
+		confirmChan: make(chan bool),
+		done:        false,
+	}
+
+	vm.progressMax = int(timeout.Seconds())
+	vm.progress = vm.progressMax
+	vm.waitingBar = mauview.NewProgressBar().
+		SetMax(vm.progressMax).
+		SetProgress(vm.progress).
+		SetIndeterminate(false)
+
+	vm.infoText = mauview.NewTextView()
+	vm.infoText.SetText(fmt.Sprintf("Waiting for %s\nto accept", device.UserID))
+
+	vm.emojiText = &EmojiView{}
+
+	vm.inputBar = mauview.NewInputField().
+		SetBackgroundColor(tcell.ColorDefault).
+		SetPlaceholderTextColor(tcell.ColorWhite)
+
+	flex := mauview.NewFlex().
+		SetDirection(mauview.FlexRow).
+		AddFixedComponent(vm.waitingBar, 1).
+		AddFixedComponent(vm.infoText, 4).
+		AddFixedComponent(vm.emojiText, 4).
+		AddFixedComponent(vm.inputBar, 1)
+
+	vm.container = mauview.NewBox(flex).
+		SetBorder(true).
+		SetTitle("Interactive verification")
+
+	vm.Component = mauview.Center(vm.container, 45, 12).SetAlwaysFocusChild(true)
+
+	go vm.decrementWaitingBar()
+
+	return vm
+}
+
+func (vm *VerificationModal) decrementWaitingBar() {
+	for {
+		select {
+		case <-time.Tick(time.Second):
+			if vm.progress <= 0 {
+				vm.waitingBar.SetIndeterminate(true)
+				vm.parent.parent.app.SetRedrawTicker(100 * time.Millisecond)
+				return
+			}
+			vm.progress--
+			vm.waitingBar.SetProgress(vm.progress)
+			vm.parent.parent.Render()
+		case <-vm.stopWaiting:
+			return
+		}
+	}
+}
+
+func (vm *VerificationModal) VerificationMethods() []crypto.VerificationMethod {
+	return []crypto.VerificationMethod{crypto.VerificationMethodEmoji{}, crypto.VerificationMethodDecimal{}}
+}
+
+func (vm *VerificationModal) VerifySASMatch(_ *crypto.DeviceIdentity, data crypto.SASData) bool {
+	var typeName string
+	if data.Type() == event.SASDecimal {
+		typeName = "numbers"
+	} else if data.Type() == event.SASEmoji {
+		typeName = "emojis"
+	} else {
+		return false
+	}
+	vm.infoText.SetText(fmt.Sprintf(
+		"Check if the other device is showing the\n"+
+			"same %s as below, then type \"yes\" to\n"+
+			"accept, or \"no\" to reject", typeName))
+	vm.inputBar.
+		SetTextColor(tcell.ColorWhite).
+		SetBackgroundColor(tcell.ColorDarkCyan).
+		SetPlaceholder("Type \"yes\" or \"no\"").
+		Focus()
+	vm.emojiText.Data = data
+	vm.parent.parent.Render()
+	vm.progress = vm.progressMax
+	confirm := <-vm.confirmChan
+	vm.progress = vm.progressMax
+	vm.emojiText.Data = nil
+	vm.infoText.SetText(fmt.Sprintf("Waiting for %s\nto confirm", vm.device.UserID))
+	vm.parent.parent.Render()
+	return confirm
+}
+
+func (vm *VerificationModal) OnCancel(cancelledByUs bool, reason string, _ event.VerificationCancelCode) {
+	vm.waitingBar.SetIndeterminate(false).SetMax(100).SetProgress(100)
+	vm.parent.parent.app.SetRedrawTicker(1 * time.Minute)
+	if cancelledByUs {
+		vm.infoText.SetText(fmt.Sprintf("Verification failed: %s", reason))
+	} else {
+		vm.infoText.SetText(fmt.Sprintf("Verification cancelled by %s: %s", vm.device.UserID, reason))
+	}
+	vm.inputBar.SetPlaceholder("Press enter to close the dialog")
+	vm.stopWaiting <- struct{}{}
+	vm.done = true
+	vm.parent.parent.Render()
+}
+
+func (vm *VerificationModal) OnSuccess() {
+	vm.waitingBar.SetIndeterminate(false).SetMax(100).SetProgress(100)
+	vm.parent.parent.app.SetRedrawTicker(1 * time.Minute)
+	vm.infoText.SetText(fmt.Sprintf("Successfully verified %s (%s) of %s", vm.device.Name, vm.device.DeviceID, vm.device.UserID))
+	vm.inputBar.SetPlaceholder("Press enter to close the dialog")
+	vm.stopWaiting <- struct{}{}
+	vm.done = true
+	vm.parent.parent.Render()
+	if vm.parent.config.SendToVerifiedOnly {
+		// Hacky way to make new group sessions after verified
+		vm.parent.matrix.Crypto().(*crypto.OlmMachine).OnDevicesChanged(vm.device.UserID)
+	}
+}
+
+func (vm *VerificationModal) OnKeyEvent(event mauview.KeyEvent) bool {
+	if vm.done {
+		if event.Key() == tcell.KeyEnter || event.Key() == tcell.KeyEsc {
+			vm.parent.HideModal()
+			return true
+		}
+		return false
+	} else if vm.emojiText.Data == nil {
+		debug.Print("Ignoring pre-emoji key event")
+		return false
+	}
+	if event.Key() == tcell.KeyEnter {
+		text := strings.ToLower(strings.TrimSpace(vm.inputBar.GetText()))
+		if text == "yes" {
+			debug.Print("Confirming verification")
+			vm.confirmChan <- true
+		} else if text == "no" {
+			debug.Print("Rejecting verification")
+			vm.confirmChan <- false
+		}
+		vm.inputBar.
+			SetPlaceholder("").
+			SetTextAndMoveCursor("").
+			SetBackgroundColor(tcell.ColorDefault).
+			SetTextColor(tcell.ColorDefault)
+		return true
+	} else {
+		return vm.inputBar.OnKeyEvent(event)
+	}
+}
+
+func (vm *VerificationModal) Focus() {
+	vm.container.Focus()
+}
+
+func (vm *VerificationModal) Blur() {
+	vm.container.Blur()
+}
diff --git a/ui/view-main.go b/ui/view-main.go
index 0f6098c..fc1b9c9 100644
--- a/ui/view-main.go
+++ b/ui/view-main.go
@@ -22,15 +22,15 @@ import (
 	"os"
 	"sync/atomic"
 	"time"
-	"unicode"
 
 	sync "github.com/sasha-s/go-deadlock"
 
-	"maunium.net/go/gomuks/ui/messages"
-	"maunium.net/go/mautrix/id"
 	"maunium.net/go/mauview"
 	"maunium.net/go/tcell"
 
+	"maunium.net/go/gomuks/ui/messages"
+	"maunium.net/go/mautrix/id"
+
 	"maunium.net/go/gomuks/config"
 	"maunium.net/go/gomuks/debug"
 	"maunium.net/go/gomuks/interface"
@@ -139,18 +139,6 @@ func (view *MainView) InputChanged(roomView *RoomView, text string) {
 	}
 }
 
-func findWordToTabComplete(text string) string {
-	output := ""
-	runes := []rune(text)
-	for i := len(runes) - 1; i >= 0; i-- {
-		if unicode.IsSpace(runes[i]) {
-			break
-		}
-		output = string(runes[i]) + output
-	}
-	return output
-}
-
 func (view *MainView) ShowBare(roomView *RoomView) {
 	if roomView == nil {
 		return