WIP: feat: SOCK4 Proxy 対応

tksugimoto · Sep 28, 2022 · 2da8bd2 · 2da8bd2
1 parent 7a158e5
commit 2da8bd2
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diff --git a/README.md b/README.md
@@ -83,3 +83,10 @@ Host github.com gist.github.com
 	# node <filepath> 形式での実行も可能
 	# ProxyCommand		node ~/code/connect-to-http-proxy/index.js proxy.intra.example.co.jp:8080 %h %p
 ```
+
+## SOCKS4 の使用
+`-S` を `proxyHost:Port` の前に入れる
+
+```
+connect-to-http-proxy -S proxy.intra.example.co.jp:1080 example.com 80
+```
diff --git a/connect.js b/connect.js
@@ -1,4 +1,5 @@
 const http = require('http');
+const net = require('net');
 const assert = require('assert');
 
 /**
@@ -8,8 +9,9 @@ const assert = require('assert');
  * @param {string} destPort destination-server port (numeric string)
  * @param {NodeJS.ReadStream} inputStream stream supplying input like process.stdin
  * @param {NodeJS.WriteStream} outputStream stream that accepts output like process.stdout
+ * @param {Boolean} isSocks4 use SOCKS4. default: false = HTTP Proxy mode
  */
-function connect(proxyServerHosts, destHostname, destPort, inputStream, outputStream) {
+function connect(proxyServerHosts, destHostname, destPort, inputStream, outputStream, isSocks4 = false) {
     assert(proxyServerHosts, 'http-proxy-server arg ("hostname:port") required.');
     assert(destHostname, 'destination-server hostname arg required.');
     assert(destPort, 'destination-server port arg required.');
@@ -33,6 +35,43 @@ function connect(proxyServerHosts, destHostname, destPort, inputStream, outputSt
                 port: proxyPort,
             } = new URL(`http://${proxyServerHost}`);
 
+            if (isSocks4) {
+                assert(/^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)(\.(?!$)|$)){4}$/.test(destHostname), `destination-server(${destHostname}) must be IPv4.`);
+                const proxyRequest = net.createConnection(proxyPort, proxyHostname);
+
+                const uint8 = new Uint8Array(9);
+                uint8[0] = 4; // version number
+                uint8[1] = 1; // command code: CONNECT
+                const portView = new DataView(uint8.buffer, 2, 2); // destination port
+                portView.setInt16(0, Number(destPort), /* littleEndian  = */ false);
+                uint8.set(destHostname.split('.').map(Number), 4); // destination IP
+                uint8[8] = 0; // USERID and NULL: null
+                proxyRequest.write(uint8);
+
+                const timeoutMs = 500;
+                setTimeout(() => {
+                    promise.catch(() => {
+                        proxyRequest.destroy();
+                    });
+                    reject(`Connection timeout to ${proxyHostname}:${proxyPort} (${timeoutMs} ms)`);
+                }, timeoutMs);
+                proxyRequest.once('readable', () => {
+                    const data = proxyRequest.read(8); // Socks Response: 8 Bytes
+                    const response = new DataView(data.buffer);
+                    const resultCode = response.getInt8(1);
+                    if (resultCode !== 90) { // request granted
+                        reject(`Socks server result code: ${resultCode}`);
+                        return;
+                    }
+                    resolve(proxyRequest);
+                });
+                proxyRequest.on('error', err => {
+                    reject(err);
+                });
+                // TODO: 共通化
+                return;
+            }
+
             const proxyRequestOptions = {
                 hostname: proxyHostname,
                 port: proxyPort,

diff --git a/index.js b/index.js
@@ -2,8 +2,16 @@
 
 const connect = require('./connect');
 
-const proxyServerHosts = process.argv[2];
-const destHostname = process.argv[3];
-const destPort = process.argv[4];
+if (process.argv[2] === '-S') {
+    const proxyServerHosts = process.argv[3];
+    const destHostname = process.argv[4];
+    const destPort = process.argv[5];
 
-connect(proxyServerHosts, destHostname, destPort, process.stdin, process.stdout);
+    connect(proxyServerHosts, destHostname, destPort, process.stdin, process.stdout, /* isSocks4 = */ true);
+} else {
+    const proxyServerHosts = process.argv[2];
+    const destHostname = process.argv[3];
+    const destPort = process.argv[4];
+
+    connect(proxyServerHosts, destHostname, destPort, process.stdin, process.stdout);
+}