// 示例代码：基于JWT的身份验证模块

const jwt = require('jsonwebtoken');

function authenticateToken(req, res, next) {

const authHeader = req.headers['authorization'];

const token = authHeader && authHeader.split(' ')[1];

if (token == null) return res.sendStatus(401);

jwt.verify(token, process.env.ACCESS_TOKEN_SECRET, (err, user) => {

if (err) return res.sendStatus(403);

req.user = user;

next();

});

}

module.exports = authenticateToken;

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// 示例代码：AES-256加密算法实现

const crypto = require('crypto');

function encrypt(data, key) {

const iv = crypto.randomBytes(16);

const cipher = crypto.createCipheriv('aes-256-cbc', Buffer.from(key), iv);

let encrypted = cipher.update(data);

encrypted = Buffer.concat([encrypted, cipher.final()]);

return iv.toString('hex') + ':' + encrypted.toString('hex');

}

function decrypt(data, key) {

const parts = data.split(':');

const iv = Buffer.from(parts[0], 'hex');

const encryptedText = Buffer.from(parts[1], 'hex');

const decipher = crypto.createDecipheriv('aes-256-cbc', Buffer.from(key), iv);

let decrypted = decipher.update(encryptedText);

decrypted = Buffer.concat([decrypted, decipher.final()]);

return decrypted.toString();

}

module.exports = { encrypt, decrypt };

]]>