Deterministic storage using WebAuthn
npm install @hazae41/webauthnstorageDeterministic storage using WebAuthn
``bash`
npm install @hazae41/webauthnstorage
Use WebAuthn as a authentication-protected storage of arbitrary bytes
This WON'T use any cryptoprocessor (HSM, Secure Enclave) as it stores the bytes in userHandle (probably on disk)
This is only used to prevent unauthenticated access to the stored values
Supply-chain attacks, phishing, misclick, phone-left-on-the-table attack would still require user authentication before accessing the data
`tsx
import { webAuthnStorage } from "@hazae41/webauthnstorage"
async function create() {
/**
* Generate a new private key
*/
const bytes = crypto.getRandomValues(new Uint8Array(32))
/**
* Store the private key into authenticated storage
*/
const handle = await webAuthnStorage.create("My Private Key", bytes)
/**
* Store the handle to the private key into some unauthenticated storage
*/
const cache = await caches.open("my-storage")
const request = new Request("my-private-key")
const response = new Response(handle)
await cache.put(request, response)
}
async function get() {
/**
* Retrieve the handle to the private key from some unauthenticated storage
*/
const cache = await caches.open("my-storage")
const request = new Request("my-private-key")
const response = await cache.match(request)
const handle = new Uint8Array(await response.arrayBuffer())
/**
* Retrieve the private key from authenticated storage
*/
const bytes = await webAuthnStorage.get(handle)
}
`
Values must have a maximum length of 64 bytes
https://github.com/w3c/webauthn/issues/1302
I recommend only storing private keys, signatures, and identifiers
This requires user interaction on most browsers
e.g. You have to create and get when the user clicks a button
`tsx
const [handle, setHandle] = useState
const onCreateClick = useCallback(async () => {
const bytes = crypto.getRandomValues(new Uint8Array(32))
const handle = await webAuthnStorage.create("My Private Key", bytes)
setHandle(handle)
}, [])
const onGetClick = useCallback(async () => {
const bytes = await webAuthnStorage.get(handle)
console.log(bytes)
}, [handle])
return <>
``