Easy-to-use timebased one time password(TOTP) generator, competible with Google Authenticator.
npm install totp-authEasy-to-use timebased one time password(TOTP) generator, compatible with Google Authenticator.
``shellpnpm
pnpm i totp-auth
Usage
js
import { createTOTP, countdown } from "totp-auth"
import { setInterval } from "timers/promises"//secret from service provider
const secret = "abcd1234"
let totp = createTOTP(secret)
let expire = countdown()
// current TOTP and expiring time in seconds
console.log(
TOTP: ${totp}, expire: ${expire})// keep counting down and refresh TOTP every 30 sec
for await (let _ of setInterval(1000)) {
const cnt = countdown()
if (cnt >= expire) totp = createTOTP(secret)
expire = cnt
console.log(
TOTP: ${totp}, expire: ${expire})
}
`$3
Not all strings can be secret key, invalid secret key will return a customizable error message.
js
// invalid secret -> default error message
createTOTP('asdf') // returns "invalid secret" // invalid secret w/ custom error message
createTOTP('asdf', undefined, 'bad key') // returns "bad key"
`Source Code
https://github.com/hoishing/totp-auth
$3
1. create base32 representation of the credential
1. calculate HMAC hash from the credential with current time
1. shift and trim 6 digit TOTP from the hash above
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Both
and countdown` are pure functions. Unit test with Jest are included.The TOTP output could also simply verified by Google Authenticator output.
Algorithm ref: http://jsfiddle.net/russau/ch8PK/
HMAC lib: https://github.com/Caligatio/jsSHA
- How can I extract secret keys from Google Authenticator?
- use another npm package: https://github.com/krissrex/google-authenticator-exporter
- use chrome extension: https://authenticator.cc/
Open a github issue or ping me on Twitter