add new module of queries limitation control

2025-02-24 18:08:55 +03:00 · 2025-02-24 18:08:55 +03:00 · 5d32580580
commit 5d32580580
parent 2e4aa8b5bd
1 changed files with 109 additions and 0 deletions
--- a/modules/antiddos.js
+++ b/modules/antiddos.js
@ -0,0 +1,109 @@
+const { NetHelperModule } = global.moduleApi;
+const express = require("express");
+const captcha = require("draw-captcha");
+
+const HTTPServer = require("../components/_http");
+
+const captchaPage = `<!DOCTYPE html><html><head><title>Captcha handling required</title><meta name="viewport" content="width=device-width, initial-scale=1"><meta charset="utf-8"></head><body>
+    <center>
+        <h1>Enter captcha</h1>
+        <p><img src=:captchaImg:></img></p>
+        <form action="/captcha-solve/:sid:/:from:" method="get">
+            <p><input type="label" name="solve"> <input type="submit" id="solve-captcha"></p>
+        </form>
+    </center>
+</body></html>`;
+
+function randint (min, max) {
+    return Math.floor(Math.random() * (max - min + 1) + min);
+}
+
+async function getCaptchaPage (fromUrl) {
+    const sidDict = "1234567890abcdef";
+    let sid = "";
+    for (let i = 0; i < 32; i++) {
+        sid += sidDict[randint(0, 15)];
+    }
+    const captchaObject = new captcha.MasterCaptcha();
+    getCaptchaPage.sids[sid] = await captchaObject.setupRandomCaptcha();
+    return captchaPage
+        .replace(new RegExp(":captchaImg:"), `/captcha/${sid}`)
+        .replace(new RegExp(":from:"), Buffer.from(fromUrl).toString("hex"))
+        .replace(new RegExp(":sid:"), sid);    
+}
+getCaptchaPage.sids = new Object();
+
+module.exports = class ExampleMdoule extends NetHelperModule {
+    constructor () {
+        super();
+        this.router = express.Router();
+        
+        this.lastUptime = new Date(new Date().getTime() + 3600000);
+        this.queryCount = 0;
+        this.ipWhiteListed = new Object();
+        
+        this.querylimit = new this.statics.Operator("querylimit", (argv) => {
+            if (argv.length !== 1) return false;
+            return !Number.isNaN(+argv[0]);
+        }, (argv, self, syntaxTree) => {
+            if (!(syntaxTree.Type.prototype instanceof HTTPServer)) {
+                throw new SyntaxError("Unsupported type of server");
+            }
+            let [ queriesLimit ] = argv;
+            queriesLimit = +queriesLimit;
+            
+            const router = this.router;
+            
+            router.use(async (req, res, next) => {
+                req.adsEx = req.adsEx ?? {};
+                if (this.lastUptime <= new Date()) {
+                    this.lastUptime = new Date(this.lastUptime.getTime() + 3600000);
+                    this.queryCount = 1;
+                    this.ipWhiteListed = new Object();
+                } else
+                    this.queryCount++;
+                if (this.queryCount > queriesLimit) {
+                    //this.lastUptime = new Date(new Date().getTime() + 3600000);
+                    req.adsEx.needsCaptcha = this.ipWhiteListed[req.realip] !== true;
+                }
+                return next();
+            });
+            
+            router.get("/captcha/:sid", async (req, res, next) => {
+                if (!req.adsEx.needsCaptcha)
+                    return next();
+                const sid = req.params.sid;
+                const content = getCaptchaPage.sids[sid];
+                if (content === undefined) {
+                    res.set("Content-Type", "text/plain");
+                    return res.status(400).send("Invalid SID. Captcha was solved or not found");
+                }
+                res.set("Content-Type", "image/jpeg");
+                res.send(content.buffer);
+            });
+            
+            router.get("/captcha-solve/:sid/:redirectTo", async (req, res) => {
+                const sid = req.params.sid;
+                const content = getCaptchaPage.sids[sid];
+                const redirectTo = Buffer.from(req.params.redirectTo, "hex").toString("utf8");
+                const isSolved = req.query.solve?.toLowerCase() === content?.code;
+                this.ipWhiteListed[req.realip] = isSolved;
+                req.adsEx.needsCaptcha = !isSolved;
+                res.redirect(redirectTo);
+            });
+            
+            router.use(async (req, res, next) => {
+                if (!req.adsEx.needsCaptcha)
+                    return next();
+                res.send(await getCaptchaPage(req.originalUrl));
+            });
+        });
+        
+        this.operators.push(this.querylimit);
+    }
+
+    bind (type) {
+        super.bind(type);
+        this.serverType.routelist.push(this.router);
+    }
+};