// 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 keystore
import (
"bufio"
"encoding/json"
"fmt"
"os"
"path/filepath"
"sort"
"strings"
"sync"
"time"
"github.com/ava-labs/coreth/accounts"
"github.com/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/log"
mapset "github.com/deckarep/golang-set"
)
// Minimum amount of time between cache reloads. This limit applies if the platform does
// not support change notifications. It also applies if the keystore directory does not
// exist yet, the code will attempt to create a watcher at most this often.
const minReloadInterval = 2 * time.Second
type accountsByURL []accounts.Account
func (s accountsByURL) Len() int { return len(s) }
func (s accountsByURL) Less(i, j int) bool { return s[i].URL.Cmp(s[j].URL) < 0 }
func (s accountsByURL) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
// AmbiguousAddrError is returned when attempting to unlock
// an address for which more than one file exists.
type AmbiguousAddrError struct {
Addr common.Address
Matches []accounts.Account
}
func (err *AmbiguousAddrError) Error() string {
files := ""
for i, a := range err.Matches {
files += a.URL.Path
if i < len(err.Matches)-1 {
files += ", "
}
}
return fmt.Sprintf("multiple keys match address (%s)", files)
}
// accountCache is a live index of all accounts in the keystore.
type accountCache struct {
keydir string
watcher *watcher
mu sync.Mutex
all accountsByURL
byAddr map[common.Address][]accounts.Account
throttle *time.Timer
notify chan struct{}
fileC fileCache
}
func newAccountCache(keydir string) (*accountCache, chan struct{}) {
ac := &accountCache{
keydir: keydir,
byAddr: make(map[common.Address][]accounts.Account),
notify: make(chan struct{}, 1),
fileC: fileCache{all: mapset.NewThreadUnsafeSet()},
}
ac.watcher = newWatcher(ac)
return ac, ac.notify
}
func (ac *accountCache) accounts() []accounts.Account {
ac.maybeReload()
ac.mu.Lock()
defer ac.mu.Unlock()
cpy := make([]accounts.Account, len(ac.all))
copy(cpy, ac.all)
return cpy
}
func (ac *accountCache) hasAddress(addr common.Address) bool {
ac.maybeReload()
ac.mu.Lock()
defer ac.mu.Unlock()
return len(ac.byAddr[addr]) > 0
}
func (ac *accountCache) add(newAccount accounts.Account) {
ac.mu.Lock()
defer ac.mu.Unlock()
i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Cmp(newAccount.URL) >= 0 })
if i < len(ac.all) && ac.all[i] == newAccount {
return
}
// newAccount is not in the cache.
ac.all = append(ac.all, accounts.Account{})
copy(ac.all[i+1:], ac.all[i:])
ac.all[i] = newAccount
ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
}
// note: removed needs to be unique here (i.e. both File and Address must be set).
func (ac *accountCache) delete(removed accounts.Account) {
ac.mu.Lock()
defer ac.mu.Unlock()
ac.all = removeAccount(ac.all, removed)
if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
delete(ac.byAddr, removed.Address)
} else {
ac.byAddr[removed.Address] = ba
}
}
// deleteByFile removes an account referenced by the given path.
func (ac *accountCache) deleteByFile(path string) {
ac.mu.Lock()
defer ac.mu.Unlock()
i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Path >= path })
if i < len(ac.all) && ac.all[i].URL.Path == path {
removed := ac.all[i]
ac.all = append(ac.all[:i], ac.all[i+1:]...)
if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
delete(ac.byAddr, removed.Address)
} else {
ac.byAddr[removed.Address] = ba
}
}
}
func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.Account {
for i := range slice {
if slice[i] == elem {
return append(slice[:i], slice[i+1:]...)
}
}
return slice
}
// find returns the cached account for address if there is a unique match.
// The exact matching rules are explained by the documentation of accounts.Account.
// Callers must hold ac.mu.
func (ac *accountCache) find(a accounts.Account) (accounts.Account, error) {
// Limit search to address candidates if possible.
matches := ac.all
if (a.Address != common.Address{}) {
matches = ac.byAddr[a.Address]
}
if a.URL.Path != "" {
// If only the basename is specified, complete the path.
if !strings.ContainsRune(a.URL.Path, filepath.Separator) {
a.URL.Path = filepath.Join(ac.keydir, a.URL.Path)
}
for i := range matches {
if matches[i].URL == a.URL {
return matches[i], nil
}
}
if (a.Address == common.Address{}) {
return accounts.Account{}, ErrNoMatch
}
}
switch len(matches) {
case 1:
return matches[0], nil
case 0:
return accounts.Account{}, ErrNoMatch
default:
err := &AmbiguousAddrError{Addr: a.Address, Matches: make([]accounts.Account, len(matches))}
copy(err.Matches, matches)
sort.Sort(accountsByURL(err.Matches))
return accounts.Account{}, err
}
}
func (ac *accountCache) maybeReload() {
ac.mu.Lock()
if ac.watcher.running {
ac.mu.Unlock()
return // A watcher is running and will keep the cache up-to-date.
}
if ac.throttle == nil {
ac.throttle = time.NewTimer(0)
} else {
select {
case <-ac.throttle.C:
default:
ac.mu.Unlock()
return // The cache was reloaded recently.
}
}
// No watcher running, start it.
ac.watcher.start()
ac.throttle.Reset(minReloadInterval)
ac.mu.Unlock()
ac.scanAccounts()
}
func (ac *accountCache) close() {
ac.mu.Lock()
ac.watcher.close()
if ac.throttle != nil {
ac.throttle.Stop()
}
if ac.notify != nil {
close(ac.notify)
ac.notify = nil
}
ac.mu.Unlock()
}
// scanAccounts checks if any changes have occurred on the filesystem, and
// updates the account cache accordingly
func (ac *accountCache) scanAccounts() error {
// Scan the entire folder metadata for file changes
creates, deletes, updates, err := ac.fileC.scan(ac.keydir)
if err != nil {
log.Debug("Failed to reload keystore contents", "err", err)
return err
}
if creates.Cardinality() == 0 && deletes.Cardinality() == 0 && updates.Cardinality() == 0 {
return nil
}
// Create a helper method to scan the contents of the key files
var (
buf = new(bufio.Reader)
key struct {
Address string `json:"address"`
}
)
readAccount := func(path string) *accounts.Account {
fd, err := os.Open(path)
if err != nil {
log.Trace("Failed to open keystore file", "path", path, "err", err)
return nil
}
defer fd.Close()
buf.Reset(fd)
// Parse the address.
key.Address = ""
err = json.NewDecoder(buf).Decode(&key)
addr := common.HexToAddress(key.Address)
switch {
case err != nil:
log.Debug("Failed to decode keystore key", "path", path, "err", err)
case (addr == common.Address{}):
log.Debug("Failed to decode keystore key", "path", path, "err", "missing or zero address")
default:
return &accounts.Account{
Address: addr,
URL: accounts.URL{Scheme: KeyStoreScheme, Path: path},
}
}
return nil
}
// Process all the file diffs
start := time.Now()
for _, p := range creates.ToSlice() {
if a := readAccount(p.(string)); a != nil {
ac.add(*a)
}
}
for _, p := range deletes.ToSlice() {
ac.deleteByFile(p.(string))
}
for _, p := range updates.ToSlice() {
path := p.(string)
ac.deleteByFile(path)
if a := readAccount(path); a != nil {
ac.add(*a)
}
}
end := time.Now()
select {
case ac.notify <- struct{}{}:
default:
}
log.Trace("Handled keystore changes", "time", end.Sub(start))
return nil
}