dendritejs: Persist ed25519 keys in localforage (#1046)

This commit is contained in:
Kegsay 2020-05-19 12:09:52 +01:00 committed by GitHub
parent b730e21892
commit 8b3100935c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

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@ -20,6 +20,7 @@ import (
"crypto/ed25519"
"fmt"
"net/http"
"syscall/js"
"github.com/matrix-org/dendrite/appservice"
"github.com/matrix-org/dendrite/clientapi"
@ -49,11 +50,89 @@ func init() {
fmt.Println("dendrite.js starting...")
}
const keyNameEd25519 = "_go_ed25519_key"
func readKeyFromLocalStorage() (key ed25519.PrivateKey, err error) {
localforage := js.Global().Get("localforage")
if !localforage.Truthy() {
err = fmt.Errorf("readKeyFromLocalStorage: no localforage")
return
}
// https://localforage.github.io/localForage/
item, ok := await(localforage.Call("getItem", keyNameEd25519))
if !ok || !item.Truthy() {
err = fmt.Errorf("readKeyFromLocalStorage: no key in localforage")
return
}
fmt.Println("Found key in localforage")
// extract []byte and make an ed25519 key
seed := make([]byte, 32, 32)
js.CopyBytesToGo(seed, item)
return ed25519.NewKeyFromSeed(seed), nil
}
func writeKeyToLocalStorage(key ed25519.PrivateKey) error {
localforage := js.Global().Get("localforage")
if !localforage.Truthy() {
return fmt.Errorf("writeKeyToLocalStorage: no localforage")
}
// make a Uint8Array from the key's seed
seed := key.Seed()
jsSeed := js.Global().Get("Uint8Array").New(len(seed))
js.CopyBytesToJS(jsSeed, seed)
// write it
localforage.Call("setItem", keyNameEd25519, jsSeed)
return nil
}
// taken from https://go-review.googlesource.com/c/go/+/150917
// await waits until the promise v has been resolved or rejected and returns the promise's result value.
// The boolean value ok is true if the promise has been resolved, false if it has been rejected.
// If v is not a promise, v itself is returned as the value and ok is true.
func await(v js.Value) (result js.Value, ok bool) {
if v.Type() != js.TypeObject || v.Get("then").Type() != js.TypeFunction {
return v, true
}
done := make(chan struct{})
onResolve := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
result = args[0]
ok = true
close(done)
return nil
})
defer onResolve.Release()
onReject := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
result = args[0]
ok = false
close(done)
return nil
})
defer onReject.Release()
v.Call("then", onResolve, onReject)
<-done
return
}
func generateKey() ed25519.PrivateKey {
_, priv, err := ed25519.GenerateKey(nil)
// attempt to look for a seed in JS-land and if it exists use it.
priv, err := readKeyFromLocalStorage()
if err == nil {
fmt.Println("Read key from localStorage")
return priv
}
// generate a new key
fmt.Println(err, " : Generating new ed25519 key")
_, priv, err = ed25519.GenerateKey(nil)
if err != nil {
logrus.Fatalf("Failed to generate ed25519 key: %s", err)
}
if err := writeKeyToLocalStorage(priv); err != nil {
fmt.Println("failed to write key to localStorage: ", err)
// non-fatal, we'll just have amnesia for a while
}
return priv
}