node中的crypto模块操作方法

const crypto = require('crypto');
const encryptSymmetric = (key, plaintext) => {
  const iv = crypto.randomBytes(12).toString('base64');
  const cipher = crypto.createCipheriv(
    "aes-256-gcm", 
    Buffer.from(key, 'base64'), 
    Buffer.from(iv, 'base64')
  );
  let ciphertext = cipher.update(plaintext, 'utf8', 'base64');
  ciphertext += cipher.final('base64');
  const tag = cipher.getAuthTag()
  return { ciphertext, tag }
}
const plaintext = "encrypt me";
const key = crypto.randomBytes(32).toString('base64');
const { ciphertext, iv, tag } = encryptSymmetric(key, plaintext);

const plaintext = "encrypt me";
const key = crypto.randomBytes(32).toString('base64');

const encryptSymmetric = (key, plaintext) => {
  // 创建随机初始化向量
  const iv = crypto.randomBytes(12).toString('base64');
  // 创建一个密码对象
  const cipher = crypto.createCipheriv("aes-256-gcm", key, iv);
  // 使用明文更新 cipher 对象以进行加密
  let ciphertext = cipher.update(plaintext, 'utf8', 'base64');
  // 完成加密过程
  ciphertext += cipher.final('base64');
  // 检索加密的身份验证标签
  const tag = cipher.getAuthTag();
  return { ciphertext, iv, tag };
}

const decryptSymmetric = (key, ciphertext, iv, tag) => {
  const decipher = crypto.createDecipheriv(
    "aes-256-gcm", 
    Buffer.from(key, 'base64'),
    Buffer.from(iv, 'base64')
  );
  decipher.setAuthTag(Buffer.from(tag, 'base64'));
  let plaintext = decipher.update(ciphertext, 'base64', 'utf8');
  plaintext += decipher.final('utf8');
  return plaintext;
}
const plaintext = decryptSymmetric(key, ciphertext, iv, tag);

const decryptSymmetric = (key, ciphertext, iv, tag) => {
  // 创建一个解密对象
  const decipher = crypto.createDecipheriv(
    "aes-256-gcm", 
    Buffer.from(key, 'base64'),
    Buffer.from(iv, 'base64')
  );
  // 设置解密对象 decipher 的认证标签
  decipher.setAuthTag(Buffer.from(tag, 'base64'));
  // 使用 Base64 编码的密文更新解密对象
  let plaintext = decipher.update(ciphertext, 'base64', 'utf8');
  // 完成解密
  plaintext += decipher.final('utf8');
  return plaintext;
}