async function hashString(str) {
  const encoder = new TextEncoder();
  const data = encoder.encode(str);
  const hashBuffer = await crypto.subtle.digest('SHA-256', data);
  return Array.from(new Uint8Array(hashBuffer))
    .map(b => b.toString(16).padStart(2, '0'))
    .join('');
}
// 使用示例
hashString('hello world').then(console.log); // 输出: "b94d..."

async function encryptAES(keyStr, plaintext) {
  const encoder = new TextEncoder();
  const key = await crypto.subtle.importKey(
    'raw',
    encoder.encode(keyStr),
    { name: 'AES-GCM' },
    false,
    ['encrypt']
  );
  const iv = crypto.getRandomValues(new Uint8Array(12)); // 初始化向量
  const ciphertext = await crypto.subtle.encrypt(
    { name: 'AES-GCM', iv },
    key,
    encoder.encode(plaintext)
  );
  return { ciphertext, iv };
}

async function decryptAES(keyStr, { ciphertext, iv }) {
  const encoder = new TextEncoder();
  const key = await crypto.subtle.importKey(
    'raw',
    encoder.encode(keyStr),
    { name: 'AES-GCM' },
    false,
    ['decrypt']
  );
  const decrypted = await crypto.subtle.decrypt(
    { name: 'AES-GCM', iv },
    key,
    ciphertext
  );
  return new TextDecoder().decode(decrypted);
}

async function generateRSAKeyPair() {
  return await crypto.subtle.generateKey(
    {
      name: 'RSA-OAEP',
      modulusLength: 2048,
      publicExponent: new Uint8Array([1, 0, 1]),
      hash: 'SHA-256'
    },
    true,
    ['encrypt', 'decrypt']
  );
}

async function encryptWithPublicKey(publicKey, data) {
  const encoder = new TextEncoder();
  const encrypted = await crypto.subtle.encrypt(
    { name: 'RSA-OAEP' },
    publicKey,
    encoder.encode(data)
  );
  return encrypted;
}

async function deriveKey(password, salt) {
  const encoder = new TextEncoder();
  const baseKey = await crypto.subtle.importKey(
    'raw',
    encoder.encode(password),
    { name: 'PBKDF2' },
    false,
    ['deriveKey']
  );
  return await crypto.subtle.deriveKey(
    {
      name: 'PBKDF2',
      salt: salt,
      iterations: 100000,
      hash: 'SHA-256'
    },
    baseKey,
    { name: 'AES-GCM', length: 256 },
    true,
    ['encrypt', 'decrypt']
  );
}