Express 项目环境搭建 -- 8. 权限校验中间件

权限校验对一个后端服务来说是一个躲不开的环节，使用中间件的方式实现 Express 的权限校验。

解析.文件

其实有第三方模块解析.env文件的模块，但是还是想自己解析一下

// utils/doFile
const fs = require("fs");
const { promisify } = require("util");
const ReadFilePromise = promisify(fs.readFile);
const path = require("path");
let config = null;

/**
 * @description 获取。env 文件
 * @author bubao
 * @date 2022-01-24 19:01:13
 * @param {boolean} [force=false] 强制刷新
 * @return {*} config
 */
async function ReadDotFile(force = false) {
	if (config && !force) {
		return config;
	}
	const dotData = await ReadFilePromise(path.join(__dirname, "../.env"));
	const item = dotData.toString().split("\n").filter((v, index) => {
		return v.length;
	});
	config = {};
	console.log(item);
	item.forEach((v, i) => {
		const [key, value] = v.split("=").map(v => v.trim().replace(/"|'/g, ""));
		config[key] = value;
	});
	console.log("config", config);
	return config;
}

module.exports = ReadDotFile;

token 生成与校验解析

// utils/token
const jwt = require("jsonwebtoken");
const Redis = require("../src/db/redis");
const dotFile = require("./dotFile");
const MyError = require("./MyError");

async function generateToken(paylod, expiresIn = 60 * 60 * 2) {
	const { JWT_TOKEN } = await dotFile();
	return jwt.sign(paylod, JWT_TOKEN, {
		expiresIn
	});
}
/**
 * @description 验证 token
 * @author bubao
 * @date 2022-01-24 13:01:06
 * @param {string} token token
 * @param {number} [type=1] 1: accessToken 2:refreshToken
 */
async function verifyToken(token, type = 1) {
	let res;
	try {
		const { JWT_TOKEN } = await dotFile();
		res = jwt.verify(token, JWT_TOKEN);
	} catch (error) {
		// info token 超时或者无效 token
		throw new MyError(40003);
	}
	const redis = Redis.init();
	const redisToken = await redis.get(`${res.id}#${type === 1 ? "access_token" : "refresh_token"}`);
	if (redisToken !== token) {
		// info 用户重新登录，旧 token 失效
		throw new MyError(40003);
	}
	return res;
}

module.exports = { generateToken, verifyToken };

鉴权中间件

// src/middleware/auth.js
const Path2Regexp = require("path-to-regexp"); // 正则匹配路径
const { errcode, verifyToken } = require("../../utils/index");

function AuthenticationMiddleWare(pathObj = { }) {
	const includes = pathObj.includes;
	const excludes = pathObj.excludes;
	const [pathIncludesMap, pathExcludesMap] = [
		{ GET: {}, POST: {}, PUT: {}, DELETE: {}, OPTIONS: {} },
		{ GET: {}, POST: {}, PUT: {}, DELETE: {}, OPTIONS: {} }
	];
	Array.isArray(includes)
		? includes.forEach(item => {
			const { method, path } = item;
			pathIncludesMap[method][Path2Regexp.pathToRegexp(path)] = Path2Regexp.pathToRegexp(path);
		})
		: excludes &&
			excludes.forEach(item => {
				const { method, path } = item;
				pathExcludesMap[method][Path2Regexp.pathToRegexp(path)] = Path2Regexp.pathToRegexp(path);
			})
	;
	const f = async (req, res, next) => {
		// 如果 excludes 为空
		let needAuth = true;
		if (!pathExcludesMap && !pathIncludesMap) {
            // 都为空则对所有的路由检验 
			needAuth = true;
		} else if (pathExcludesMap) {
            // 有 excludes
			const pathList = pathExcludesMap[req.method];
			for (const element in pathList) {
				if (pathList[element].test(req.url)) {
					needAuth = false;
					break;
				}
			}
		} else {
            // 有 excludes
			needAuth = false;
			const pathList = pathIncludesMap[req.method];
			for (const element in pathList) {
				if (element.test(req.url)) {
					needAuth = true;
					break;
				}
			}
		}
		if (needAuth) {
			const Authorization = req.headers.authorization;
			if (Authorization) {
				const token = Authorization.replace(/^Bearer /, "");
				try {
					const decodeToken = await verifyToken(token);
					req.decodeToken = decodeToken;
					next();
				} catch (error) {
					const { status, body } = errcode(40003);
					res.status(status);
					res.send(body);
				}
			} else {
				const { status, body } = errcode(40002);
				res.status(status);
				res.send(body);
			}
		} else {
			next();
		}
	};
	return f;
}

module.exports = AuthenticationMiddleWare;

使用中间件

在app.js中添加中间件

const express = require("express");
const authMiddleware = require("./src/middleware/auth");

app.use(
	authMiddleware({
		excludes: [{
			method: "POST",
			path: "/api/v1/auth"
		}, {
			method: "POST",
			path: "/api/v1/register"
		}]
	})
);