研究本地服务系列文章：

1. 图一乐研究之初识Yakit
2. 图一乐研究之本地服务猎手
3. 本地服务猎手终章（本文）

前言

续上篇

几个小问题想改进一下：

1. go wasm编译文件太大，用 js 重新写个更轻量的。
2. 解决跨域问题的方案。

改进Web端口扫描

用 JavaScript 写个非常简单：

function Scanner(host = "127.0.0.1") {
    this.host = host;
    this.ports = [];
    this.probe = (port) => {
        return fetch(`http://${this.host}:${port}`, {
            method: 'HEAD',
            mode: 'no-cors',
        }).then(resp => { this.ports.push(port); }).catch(e => { /*do nothing*/try { } catch (e) { } });
    };
    this.scan = (start, end) => {
        const promises = [];
        for (let port = start; port < end; port++) {
            promises.push(this.probe(port));
        }
        return Promise.all(promises)
    }
}
s = new Scanner();
s.scan(8000, 8100).then(() => {
    s.ports.forEach(item => {
        console.log("Opened Port:", item);
    });
});

还没结束，得控制异步并发数量，不然浏览器直接跑崩…

抄网上的代码添加异步并发数量控制：

function Scanner(host = "127.0.0.1", limit = 10) {
    this.host = host;
    this.limit = limit;
    this.ports = [];

    this.probe = (port) => {
        return fetch(`http://${this.host}:${port}`,
            {
                method: 'HEAD',
                mode: 'no-cors',
            }).then(resp => {
                this.ports.push(port);
            }).catch(e => {
                const err = e.message;
                if (err.includes("exceeded while awaiting") ||
                    err.includes("ssl") ||
                    err.includes("cors") ||
                    err.includes("invalid") ||
                    err.includes("protocol")) this.ports.push(port);;
                try {/*do nothing*/ } catch (e) { }
            });
    };
    this.scan = async (start, end) => {
        const resultList = [];
        const executing = [];
        for (let port = start; port < end; port++) {
            const p = this.probe(port);
            resultList.push(p);
            if (this.limit <= end) {
                const e = p.then(() => {
                    return executing.splice(executing.indexOf(e), 1);
                });
                executing.push(e);
                if (executing.length >= this.limit) {
                    await Promise.race(executing);
                }
            }
        }
        return Promise.all(resultList);
    }
}
s = new Scanner();
s.scan(8000, 8100).then(() => {
    s.ports.forEach(item => {
        console.log("Opened Port:", item);
    });
});

对扫出来的端口进行 url fuzz 测试，把 fetch mode no-cors 移除即可，其他逻辑一样。

源码

在线测试地址：https://ac0d3r.github.io/webportscan/

源码：https://github.com/ac0d3r/webportscan