From dab2b14e89ee0105d56a3f426c207654f1b144b4 Mon Sep 17 00:00:00 2001
From: Dave Kelsey <d_kelsey@uk.ibm.com>
Date: Thu, 6 Dec 2018 14:44:59 +0000
Subject: [PATCH] [0.19.x] Rest server can be terminated by client (#4531)
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A client listening on a web socket can terminate the rest server
if it is badly behaved and doesn’t cleanly disconnect

Signed-off-by: Dave Kelsey <d_kelsey@uk.ibm.com>
---
 .../composer-rest-server/server/server.js     |  8 +++++++
 .../test/server/server.js                     | 22 +++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/packages/composer-rest-server/server/server.js b/packages/composer-rest-server/server/server.js
index 98442c25fa..e1dd91a5e4 100755
--- a/packages/composer-rest-server/server/server.js
+++ b/packages/composer-rest-server/server/server.js
@@ -192,6 +192,14 @@ module.exports = function (composer) {
                 clientTracking: true
             });
 
+            // Add a dummy error handler for a ws connection so bad websocket client
+            // doesn't kill the rest server
+            wss.on('connection', (ws) => {
+                ws.on('error', () => {
+                    // do nothing
+                });
+            });
+
             // Add a broadcast method that sends data to all connected clients.
             wss.broadcast = (data) => {
                 wss.clients.forEach((client) => {
diff --git a/packages/composer-rest-server/test/server/server.js b/packages/composer-rest-server/test/server/server.js
index 23c8b30a43..f4d3eebe03 100644
--- a/packages/composer-rest-server/test/server/server.js
+++ b/packages/composer-rest-server/test/server/server.js
@@ -23,6 +23,7 @@ const IdCard = require('composer-common').IdCard;
 const path = require('path');
 const server = require('../../server/server');
 const WebSocket = require('ws');
+const EventEmitter = require('events');
 
 const chai = require('chai');
 const should = chai.should();
@@ -341,4 +342,25 @@ describe('server', () => {
             });
     });
 
+    it('should register an error handler on connection to a websocket and it shoud no nothing when fired', () => {
+        composerConfig.websockets = true;
+        const stubWS = new EventEmitter();
+        const wsOnSpy = sinon.spy(stubWS, 'on');
+
+
+        return server(composerConfig)
+            .then((result) => {
+                result.app.should.exist;
+                result.server.should.exist;
+                const wss = result.app.get('wss');
+                wss.should.be.an.instanceOf(WebSocket.Server);
+                wss.emit('connection', stubWS);
+                sinon.assert.calledOnce(wsOnSpy);
+                sinon.assert.calledWith(wsOnSpy, 'error');
+
+                // fire the error event
+                stubWS.emit('error');
+            });
+    });
+
 });