store: prevent misuse of deleted devices

Fixes #1099

Author: tulir

client.go

@@ -503,6 +503,9 @@ func (cli *Client) connect(ctx context.Context) error {
 }
 
 func (cli *Client) unlockedConnect(ctx context.Context) error {
+	if cli.Store.Deleted {
+		return store.ErrDeviceDeleted
+	}
 	if cli.socket != nil {
 		if !cli.socket.IsConnected() {
 			cli.unlockedDisconnect()

store/sqlstore/container.go

@@ -265,17 +265,7 @@ func (c *Container) PutDevice(ctx context.Context, device *store.Device) error {
 
 func (c *Container) initializeDevice(device *store.Device) {
 	innerStore := NewSQLStore(c, *device.ID)
-	device.Identities = innerStore
-	device.Sessions = innerStore
-	device.PreKeys = innerStore
-	device.SenderKeys = innerStore
-	device.AppStateKeys = innerStore
-	device.AppState = innerStore
-	device.Contacts = innerStore
-	device.ChatSettings = innerStore
-	device.MsgSecrets = innerStore
-	device.PrivacyTokens = innerStore
-	device.EventBuffer = innerStore
+	device.SetAllStores(innerStore)
 	device.LIDs = c.LIDMap
 	device.Container = c
 	device.Initialized = true

store/store.go

@@ -9,6 +9,7 @@ package store
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"github.com/google/uuid"
@@ -226,6 +227,7 @@ type Device struct {
 	FacebookUUID uuid.UUID
 
 	Initialized   bool
+	Deleted       bool
 	Identities    IdentityStore
 	Sessions      SessionStore
 	PreKeys       PreKeyStore
@@ -259,20 +261,44 @@ func (device *Device) GetLID() types.JID {
 	return device.LID
 }
 
+var ErrDeviceDeleted = errors.New("invalid use of deleted device")
+
 func (device *Device) Save(ctx context.Context) error {
+	if device.Deleted {
+		return ErrDeviceDeleted
+	}
 	return device.Container.PutDevice(ctx, device)
 }
 
 func (device *Device) Delete(ctx context.Context) error {
+	if device.Deleted {
+		return nil
+	}
 	err := device.Container.DeleteDevice(ctx, device)
 	if err != nil {
 		return err
 	}
 	device.ID = nil
 	device.LID = types.EmptyJID
+	device.Deleted = true
+	device.SetAllStores(&NoopStore{ErrDeviceDeleted})
 	return nil
 }
 
+func (device *Device) SetAllStores(store AllSessionSpecificStores) {
+	device.Identities = store
+	device.Sessions = store
+	device.PreKeys = store
+	device.SenderKeys = store
+	device.AppStateKeys = store
+	device.AppState = store
+	device.Contacts = store
+	device.ChatSettings = store
+	device.MsgSecrets = store
+	device.PrivacyTokens = store
+	device.EventBuffer = store
+}
+
 func (device *Device) GetAltJID(ctx context.Context, jid types.JID) (types.JID, error) {
 	if device == nil {
 		return types.EmptyJID, nil