From d9b6eef1dd5f89e9bb9a2e9753b13c7f987dc7d8 Mon Sep 17 00:00:00 2001
From: Luigi Pinca <luigipinca@gmail.com>
Date: Wed, 16 Oct 2019 22:27:38 +0200
Subject: [PATCH] Use a new and closed `net.Socket` instead of a `Duplex`

---
 index.js     | 26 +++++++-------------------
 test/test.js | 31 ++++++++++++++++---------------
 2 files changed, 23 insertions(+), 34 deletions(-)

diff --git a/index.js b/index.js
index 2be8a4d2..916e333e 100644
--- a/index.js
+++ b/index.js
@@ -2,6 +2,7 @@
  * Module dependencies.
  */
 
+var assert = require('assert');
 var net = require('net');
 var tls = require('tls');
 var url = require('url');
@@ -161,23 +162,16 @@ HttpsProxyAgent.prototype.callback = function connect(req, opts, fn) {
 			// that the node core `http` can parse and handle the error status code
 			cleanup();
 
-			// the original socket is closed, and a "fake socket" Duplex is
+			// the original socket is closed, and a new closed socket is
 			// returned instead, so that the proxy doesn't get the HTTP request
 			// written to it (which may contain `Authorization` headers or other
 			// sensitive data).
 			//
 			// See: https://hackerone.com/reports/541502
 			socket.destroy();
-			socket = new stream.Duplex({
-				read() {},
-				write(chunk, encoding, callback) {
-					callback();
-				}
-			});
-
-			if (process.versions.modules === '48') {
-				socket.destroy = noop;
-			}
+			socket = new net.Socket();
+			socket.readable = true;
+
 
 			// save a reference to the concat'd Buffer for the `onsocket` callback
 			buffers = buffered;
@@ -191,15 +185,11 @@ HttpsProxyAgent.prototype.callback = function connect(req, opts, fn) {
 
 	function onsocket(socket) {
 		debug('replaying proxy buffer for failed request');
+		assert(socket.listenerCount('data') > 0);
 
 		// replay the "buffers" Buffer onto the `socket`, since at this point
 		// the HTTP module machinery has been hooked up for the user
-		if (socket.listenerCount('data') > 0) {
-			socket.emit('data', buffers);
-		} else {
-			// never?
-			throw new Error('should not happen...');
-		}
+		socket.push(buffers);
 
 		// nullify the cached Buffer instance
 		buffers = null;
@@ -250,5 +240,3 @@ function resume(socket) {
 function isDefaultPort(port, secure) {
 	return Boolean((!secure && port === 80) || (secure && port === 443));
 }
-
-function noop() {}
diff --git a/test/test.js b/test/test.js
index f4ae8c1c..61a02320 100644
--- a/test/test.js
+++ b/test/test.js
@@ -234,24 +234,25 @@ describe('HttpsProxyAgent', function() {
 				done();
 			});
 		});
-    it('should not error if the request is aborted and a fake socket is assigned to it', function(done) {
-      proxy.authenticate = function(req, fn) {
-        fn(null, false);
-      };
-
-      const proxyUri =
-        process.env.HTTP_PROXY ||
-        process.env.http_proxy ||
-        'http://127.0.0.1:' + proxyPort;
+		it('should not error if the proxy responds with 407 and the request is aborted', function(done) {
+			proxy.authenticate = function(req, fn) {
+				fn(null, false);
+			};
 
-      const req = http.get({ agent: new HttpsProxyAgent(proxyUri) });
+			const proxyUri =
+				process.env.HTTP_PROXY ||
+				process.env.http_proxy ||
+				'http://127.0.0.1:' + proxyPort;
 
-      req.on('socket', function() {
-        req.abort();
-      })
+			const req = http.get({
+				agent: new HttpsProxyAgent(proxyUri)
+			}, function(res) {
+				assert.equal(407, res.statusCode);
+				req.abort();
+			});
 
-      req.on('abort', done);
-    });
+			req.on('abort', done);
+		});
 		it('should emit an "error" event on the `http.ClientRequest` if the proxy does not exist', function(done) {
 			// port 4 is a reserved, but "unassigned" port
 			var proxyUri = 'http://127.0.0.1:4';