Discourse user-api-keys decryption

decryption.js

import { privateDecrypt, constants } from "crypto"
import fs from "fs"
import fetch from "node-fetch"

const input = `...`

// decrypt payload
const privateKey = fs.readFileSync("private.key")

const data = new Buffer.from(input, "base64")
const decrypted = privateDecrypt({ key: privateKey, padding: constants.RSA_PKCS1_PADDING }, data);

const payload = JSON.parse(decrypted)
console.log(payload)

// who is this?
fetch("https://forum.cfx.re/session/current.json", { headers: { "User-Api-Key": payload.key }})
    .then(x => x.json())
    .then(session => {
        console.log(`It's ${session.current_user.username}!`)
    })