├── LICENSE
├── README.md
└── proxy.js


/LICENSE:
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 1 | MIT License
 2 | 
 3 | Copyright (c) 2021 Tejaswi Kasat
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


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/README.md:
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 1 | # nodejs-proxy-server
 2 | A simple proxy server using net and stream modules
 3 | 
 4 | Run it using 
 5 | ```
 6 | node proxy.js
 7 | ```
 8 | 
 9 | Read full explanation here: 
10 | https://thejsway.medium.com/build-your-own-forward-and-reverse-proxy-server-using-node-js-from-scratch-eaa0f8d69e1f
11 | 


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/proxy.js:
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 1 | // Import of net module
 2 | const net = require("net");
 3 | const server = net.createServer();
 4 | 
 5 | server.on("connection", (clientToProxySocket) => {
 6 |     console.log("Client connected to proxy");
 7 |     clientToProxySocket.once("data", (data) => {
 8 |         let isTLSConnection = data.toString().indexOf("CONNECT") !== -1;
 9 | 
10 |         let serverPort = 80;
11 |         let serverAddress;
12 |         console.log(data.toString());
13 |         if (isTLSConnection) {
14 |             serverPort = 443;
15 |             serverAddress = data
16 |                 .toString()
17 |                 .split("CONNECT")[1]
18 |                 .split(" ")[1]
19 |                 .split(":")[0];
20 |         } else {
21 |             serverAddress = data.toString().split("Host: ")[1].split("\r\n")[0];
22 |         }
23 |         console.log(serverAddress);
24 | 
25 |         // Creating a connection from proxy to destination server
26 |         let proxyToServerSocket = net.createConnection(
27 |             {
28 |                 host: serverAddress,
29 |                 port: serverPort,
30 |             },
31 |             () => {
32 |                 console.log("Proxy to server set up");
33 |             }
34 |         );
35 | 
36 | 
37 |         if (isTLSConnection) {
38 |             clientToProxySocket.write("HTTP/1.1 200 OK\r\n\r\n");
39 |         } else {
40 |             proxyToServerSocket.write(data);
41 |         }
42 | 
43 |         clientToProxySocket.pipe(proxyToServerSocket);
44 |         proxyToServerSocket.pipe(clientToProxySocket);
45 | 
46 |         proxyToServerSocket.on("error", (err) => {
47 |             console.log("Proxy to server error");
48 |             console.log(err);
49 |         });
50 | 
51 |         clientToProxySocket.on("error", (err) => {
52 |             console.log("Client to proxy error");
53 |             console.log(err)
54 |         });
55 |     });
56 | });
57 | 
58 | server.on("error", (err) => {
59 |     console.log("Some internal server error occurred");
60 |     console.log(err);
61 | });
62 | 
63 | server.on("close", () => {
64 |     console.log("Client disconnected");
65 | });
66 | 
67 | server.listen(
68 |     {
69 |         host: "0.0.0.0",
70 |         port: 8080,
71 |     },
72 |     () => {
73 |         console.log("Server listening on 0.0.0.0:8080");
74 |     }
75 | );
76 | 


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