http: add regression test for smuggling content length

PR-URL: nodejs-private/node-private#284
Reviewed-By: Akshay K <iit.akshay@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Robert Nagy <ronagy@icloud.com>

test/parallel/test-http-request-smuggling-content-length.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const common = require('../common');
+const http = require('http');
+const net = require('net');
+const assert = require('assert');
+
+// Verify that a request with a space before the content length will result
+// in a 400 Bad Request.
+
+const server = http.createServer(common.mustNotCall());
+
+server.listen(0, common.mustCall(start));
+
+function start() {
+  const sock = net.connect(server.address().port);
+
+  sock.write('GET / HTTP/1.1\r\nHost: localhost:5000\r\n' +
+    'Content-Length : 5\r\n\r\nhello');
+
+  let body = '';
+  sock.setEncoding('utf8');
+  sock.on('data', (chunk) => {
+    body += chunk;
+  });
+  sock.on('end', common.mustCall(function() {
+    assert.strictEqual(body, 'HTTP/1.1 400 Bad Request\r\n' +
+      'Connection: close\r\n\r\n');
+    server.close();
+  }));
+}