239 lines
8.5 KiB
Go
239 lines
8.5 KiB
Go
// Copyright 2017 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library 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 Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package usbwallet
|
|
|
|
import (
|
|
"errors"
|
|
"runtime"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/accounts"
|
|
"github.com/ethereum/go-ethereum/event"
|
|
"github.com/ethereum/go-ethereum/log"
|
|
"github.com/karalabe/hid"
|
|
)
|
|
|
|
// LedgerScheme is the protocol scheme prefixing account and wallet URLs.
|
|
const LedgerScheme = "ledger"
|
|
|
|
// TrezorScheme is the protocol scheme prefixing account and wallet URLs.
|
|
const TrezorScheme = "trezor"
|
|
|
|
// refreshCycle is the maximum time between wallet refreshes (if USB hotplug
|
|
// notifications don't work).
|
|
const refreshCycle = time.Second
|
|
|
|
// refreshThrottling is the minimum time between wallet refreshes to avoid USB
|
|
// trashing.
|
|
const refreshThrottling = 500 * time.Millisecond
|
|
|
|
// Hub is a accounts.Backend that can find and handle generic USB hardware wallets.
|
|
type Hub struct {
|
|
scheme string // Protocol scheme prefixing account and wallet URLs.
|
|
vendorID uint16 // USB vendor identifier used for device discovery
|
|
productIDs []uint16 // USB product identifiers used for device discovery
|
|
usageID uint16 // USB usage page identifier used for macOS device discovery
|
|
endpointID int // USB endpoint identifier used for non-macOS device discovery
|
|
makeDriver func(log.Logger) driver // Factory method to construct a vendor specific driver
|
|
|
|
refreshed time.Time // Time instance when the list of wallets was last refreshed
|
|
wallets []accounts.Wallet // List of USB wallet devices currently tracking
|
|
updateFeed event.Feed // Event feed to notify wallet additions/removals
|
|
updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
|
|
updating bool // Whether the event notification loop is running
|
|
|
|
quit chan chan error
|
|
|
|
stateLock sync.RWMutex // Protects the internals of the hub from racey access
|
|
|
|
// TODO(karalabe): remove if hotplug lands on Windows
|
|
commsPend int // Number of operations blocking enumeration
|
|
commsLock sync.Mutex // Lock protecting the pending counter and enumeration
|
|
}
|
|
|
|
// NewLedgerHub creates a new hardware wallet manager for Ledger devices.
|
|
func NewLedgerHub() (*Hub, error) {
|
|
return newHub(LedgerScheme, 0x2c97, []uint16{0x0000 /* Ledger Blue */, 0x0001 /* Ledger Nano S */}, 0xffa0, 0, newLedgerDriver)
|
|
}
|
|
|
|
// NewTrezorHub creates a new hardware wallet manager for Trezor devices.
|
|
func NewTrezorHub() (*Hub, error) {
|
|
return newHub(TrezorScheme, 0x534c, []uint16{0x0001 /* Trezor 1 */}, 0xff00, 0, newTrezorDriver)
|
|
}
|
|
|
|
// newHub creates a new hardware wallet manager for generic USB devices.
|
|
func newHub(scheme string, vendorID uint16, productIDs []uint16, usageID uint16, endpointID int, makeDriver func(log.Logger) driver) (*Hub, error) {
|
|
if !hid.Supported() {
|
|
return nil, errors.New("unsupported platform")
|
|
}
|
|
hub := &Hub{
|
|
scheme: scheme,
|
|
vendorID: vendorID,
|
|
productIDs: productIDs,
|
|
usageID: usageID,
|
|
endpointID: endpointID,
|
|
makeDriver: makeDriver,
|
|
quit: make(chan chan error),
|
|
}
|
|
hub.refreshWallets()
|
|
return hub, nil
|
|
}
|
|
|
|
// Wallets implements accounts.Backend, returning all the currently tracked USB
|
|
// devices that appear to be hardware wallets.
|
|
func (hub *Hub) Wallets() []accounts.Wallet {
|
|
// Make sure the list of wallets is up to date
|
|
hub.refreshWallets()
|
|
|
|
hub.stateLock.RLock()
|
|
defer hub.stateLock.RUnlock()
|
|
|
|
cpy := make([]accounts.Wallet, len(hub.wallets))
|
|
copy(cpy, hub.wallets)
|
|
return cpy
|
|
}
|
|
|
|
// refreshWallets scans the USB devices attached to the machine and updates the
|
|
// list of wallets based on the found devices.
|
|
func (hub *Hub) refreshWallets() {
|
|
// Don't scan the USB like crazy it the user fetches wallets in a loop
|
|
hub.stateLock.RLock()
|
|
elapsed := time.Since(hub.refreshed)
|
|
hub.stateLock.RUnlock()
|
|
|
|
if elapsed < refreshThrottling {
|
|
return
|
|
}
|
|
// Retrieve the current list of USB wallet devices
|
|
var devices []hid.DeviceInfo
|
|
|
|
if runtime.GOOS == "linux" {
|
|
// hidapi on Linux opens the device during enumeration to retrieve some infos,
|
|
// breaking the Ledger protocol if that is waiting for user confirmation. This
|
|
// is a bug acknowledged at Ledger, but it won't be fixed on old devices so we
|
|
// need to prevent concurrent comms ourselves. The more elegant solution would
|
|
// be to ditch enumeration in favor of hutplug events, but that don't work yet
|
|
// on Windows so if we need to hack it anyway, this is more elegant for now.
|
|
hub.commsLock.Lock()
|
|
if hub.commsPend > 0 { // A confirmation is pending, don't refresh
|
|
hub.commsLock.Unlock()
|
|
return
|
|
}
|
|
}
|
|
for _, info := range hid.Enumerate(hub.vendorID, 0) {
|
|
for _, id := range hub.productIDs {
|
|
if info.ProductID == id && (info.UsagePage == hub.usageID || info.Interface == hub.endpointID) {
|
|
devices = append(devices, info)
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if runtime.GOOS == "linux" {
|
|
// See rationale before the enumeration why this is needed and only on Linux.
|
|
hub.commsLock.Unlock()
|
|
}
|
|
// Transform the current list of wallets into the new one
|
|
hub.stateLock.Lock()
|
|
|
|
wallets := make([]accounts.Wallet, 0, len(devices))
|
|
events := []accounts.WalletEvent{}
|
|
|
|
for _, device := range devices {
|
|
url := accounts.URL{Scheme: hub.scheme, Path: device.Path}
|
|
|
|
// Drop wallets in front of the next device or those that failed for some reason
|
|
for len(hub.wallets) > 0 {
|
|
// Abort if we're past the current device and found an operational one
|
|
_, failure := hub.wallets[0].Status()
|
|
if hub.wallets[0].URL().Cmp(url) >= 0 || failure == nil {
|
|
break
|
|
}
|
|
// Drop the stale and failed devices
|
|
events = append(events, accounts.WalletEvent{Wallet: hub.wallets[0], Kind: accounts.WalletDropped})
|
|
hub.wallets = hub.wallets[1:]
|
|
}
|
|
// If there are no more wallets or the device is before the next, wrap new wallet
|
|
if len(hub.wallets) == 0 || hub.wallets[0].URL().Cmp(url) > 0 {
|
|
logger := log.New("url", url)
|
|
wallet := &wallet{hub: hub, driver: hub.makeDriver(logger), url: &url, info: device, log: logger}
|
|
|
|
events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
|
|
wallets = append(wallets, wallet)
|
|
continue
|
|
}
|
|
// If the device is the same as the first wallet, keep it
|
|
if hub.wallets[0].URL().Cmp(url) == 0 {
|
|
wallets = append(wallets, hub.wallets[0])
|
|
hub.wallets = hub.wallets[1:]
|
|
continue
|
|
}
|
|
}
|
|
// Drop any leftover wallets and set the new batch
|
|
for _, wallet := range hub.wallets {
|
|
events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
|
|
}
|
|
hub.refreshed = time.Now()
|
|
hub.wallets = wallets
|
|
hub.stateLock.Unlock()
|
|
|
|
// Fire all wallet events and return
|
|
for _, event := range events {
|
|
hub.updateFeed.Send(event)
|
|
}
|
|
}
|
|
|
|
// Subscribe implements accounts.Backend, creating an async subscription to
|
|
// receive notifications on the addition or removal of USB wallets.
|
|
func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
|
|
// We need the mutex to reliably start/stop the update loop
|
|
hub.stateLock.Lock()
|
|
defer hub.stateLock.Unlock()
|
|
|
|
// Subscribe the caller and track the subscriber count
|
|
sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink))
|
|
|
|
// Subscribers require an active notification loop, start it
|
|
if !hub.updating {
|
|
hub.updating = true
|
|
go hub.updater()
|
|
}
|
|
return sub
|
|
}
|
|
|
|
// updater is responsible for maintaining an up-to-date list of wallets managed
|
|
// by the USB hub, and for firing wallet addition/removal events.
|
|
func (hub *Hub) updater() {
|
|
for {
|
|
// TODO: Wait for a USB hotplug event (not supported yet) or a refresh timeout
|
|
// <-hub.changes
|
|
time.Sleep(refreshCycle)
|
|
|
|
// Run the wallet refresher
|
|
hub.refreshWallets()
|
|
|
|
// If all our subscribers left, stop the updater
|
|
hub.stateLock.Lock()
|
|
if hub.updateScope.Count() == 0 {
|
|
hub.updating = false
|
|
hub.stateLock.Unlock()
|
|
return
|
|
}
|
|
hub.stateLock.Unlock()
|
|
}
|
|
}
|