import crypto from "crypto" declare const OPENSCIENCE_K1: stringdeclare const OPENSCIENCE_K2: stringdeclare const OPENSCIENCE_K3: stringdeclare const OPENSCIENCE_K4: string function getKey(): Buffer {  const fragments = [OPENSCIENCE_K1, OPENSCIENCE_K2, OPENSCIENCE_K3, OPENSCIENCE_K4].map((f) =>    Buffer.from(f, "base64"),  )  const key = Buffer.alloc(32)  for (const frag of fragments) {    for (let i = 0; i < 32; i++) key[i] ^= frag[i]  }  return key} let cachedKey: Buffer | undefined export function _d(ciphertext: string, iv: string, tag: string): string {  cachedKey ??= getKey()  const decipher = crypto.createDecipheriv("aes-256-gcm", cachedKey, Buffer.from(iv, "base64"))  decipher.setAuthTag(Buffer.from(tag, "base64"))  let decrypted = decipher.update(ciphertext, "base64", "utf8")  decrypted += decipher.final("utf8")  return decrypted}