function getKeyMaterial() {
    const password = window.prompt("Enter your password");
    const enc = new TextEncoder();
    return window.crypto.subtle.importKey(
      "raw",
      enc.encode(password),
      "PBKDF2",
      false,
      ["deriveBits", "deriveKey"]
    );
  }
  
  async function encrypt(plaintext, salt, iv) {
    const keyMaterial = await getKeyMaterial();
    const key = await window.crypto.subtle.deriveKey(
      {
        name: "PBKDF2",
        salt,
        iterations: 100000,
        hash: "SHA-256",
      },
      keyMaterial,
      { name: "AES-GCM", length: 256 },
      true,
      ["encrypt", "decrypt"]
    );

    console.log(typeof plaintext);
    const enc = new TextEncoder();
    plaintext = enc.encode(plaintext);
    console.log(typeof plaintext);

    console.log(typeof iv);
    console.log(iv);

    return window.crypto.subtle.encrypt({ name: "AES-GCM", iv }, key, plaintext);
  }

async function decrypt(ciphertext, salt, iv) {
  try {
    console.log(ciphertext);
    let keyMaterial = await getKeyMaterial();
    const key = await window.crypto.subtle.deriveKey(
      {
        name: "PBKDF2",
        salt,
        iterations: 100000,
        hash: "SHA-256",
      },
      keyMaterial,
      { name: "AES-GCM", length: 256 },
      true,
      ["encrypt", "decrypt"]
    );
    let decrypted = await window.crypto.subtle.decrypt(
      {
        name: "AES-GCM",
        iv: iv,
      },
      key,
      ciphertext
    );

    let dec = new TextDecoder();
    return dec.decode(decrypted);
  } catch (e) {
    return null;
  }
}
const salt = window.crypto.getRandomValues(new Uint8Array(16));
const iv = window.crypto.getRandomValues(new Uint8Array(12));

encrypt("Hello World", salt, iv).then(
  (ciphertext) => {
    console.log(ciphertext);
    decrypt(ciphertext, salt, iv).then(
      (plaintext) => {
        console.log(plaintext);
      }
    );
  }
);