feat(NODE-3633): add Socks5 support

bindings/node/index.d.ts

@@ -9,6 +9,16 @@ export type ClientEncryptionDataKeyProvider = 'aws' | 'azure' | 'gcp' | 'local'
 export class MongoCryptError extends Error {
 }
 
+/**
+ * A set of options for specifying a Socks5 proxy.
+ */
+export interface ProxyOptions {
+  host: string;
+  port?: number;
+  username?: string;
+  password?: string;
+}
+
 export interface ClientEncryptionCreateDataKeyCallback {
   /**
    * @param error If present, indicates an error that occurred in the creation of the data key
@@ -185,6 +195,11 @@ export interface ClientEncryptionOptions {
    */
   kmsProviders?: KMSProviders;
 
+  /**
+   * Options for specifying a Socks5 proxy to use for connecting to the KMS.
+   */
+  proxyOptions?: ProxyOptions;
+
   /**
    * TLS options for kms providers to use.
    */

bindings/node/lib/autoEncrypter.js

@@ -212,7 +212,7 @@ module.exports = function(modules) {
       context.ns = ns;
       context.document = cmd;
 
-      const stateMachine = new StateMachine(Object.assign({ bson }, options));
+      const stateMachine = new StateMachine({ bson, ...options, proxyOptions: this._proxyOptions });
       stateMachine.execute(this, context, callback);
     }
 
@@ -243,7 +243,7 @@ module.exports = function(modules) {
       // TODO: should this be an accessor from the addon?
       context.id = this._contextCounter++;
 
-      const stateMachine = new StateMachine(Object.assign({ bson }, options));
+      const stateMachine = new StateMachine({ bson, ...options, proxyOptions: this._proxyOptions });
       stateMachine.execute(this, context, callback);
     }
   }

bindings/node/lib/clientEncryption.js

@@ -65,6 +65,7 @@ module.exports = function(modules) {
     constructor(client, options) {
       this._client = client;
       this._bson = options.bson || client.topology.bson;
+      this._proxyOptions = options.proxyOptions;
 
       if (options.keyVaultNamespace == null) {
         throw new TypeError('Missing required option `keyVaultNamespace`');
@@ -198,7 +199,7 @@ module.exports = function(modules) {
 
       const dataKeyBson = bson.serialize(dataKey);
       const context = this._mongoCrypt.makeDataKeyContext(dataKeyBson, { keyAltNames });
-      const stateMachine = new StateMachine({ bson });
+      const stateMachine = new StateMachine({ bson, proxyOptions: this._proxyOptions });
 
       return promiseOrCallback(callback, cb => {
         stateMachine.execute(this, context, (err, dataKey) => {
@@ -290,7 +291,7 @@ module.exports = function(modules) {
         contextOptions.keyAltName = bson.serialize({ keyAltName });
       }
 
-      const stateMachine = new StateMachine({ bson });
+      const stateMachine = new StateMachine({ bson, proxyOptions: this._proxyOptions });
       const context = this._mongoCrypt.makeExplicitEncryptionContext(valueBuffer, contextOptions);
 
       return promiseOrCallback(callback, cb => {
@@ -335,7 +336,7 @@ module.exports = function(modules) {
       const valueBuffer = bson.serialize({ v: value });
       const context = this._mongoCrypt.makeExplicitDecryptionContext(valueBuffer);
 
-      const stateMachine = new StateMachine({ bson });
+      const stateMachine = new StateMachine({ bson, proxyOptions: this._proxyOptions });
 
       return promiseOrCallback(callback, cb => {
         stateMachine.execute(this, context, (err, result) => {

bindings/node/lib/stateMachine.js

@@ -2,6 +2,9 @@
 
 module.exports = function(modules) {
   const tls = require('tls');
+  const net = require('net');
+  const { once } = require('events');
+  const { SocksClient } = require('socks');
 
   // Try first to import 4.x name, fallback to 3.x name
   const MongoNetworkTimeoutError =
@@ -224,27 +227,69 @@ module.exports = function(modules) {
       const options = { host: parsedUrl[0], servername: parsedUrl[0], port };
       const message = request.message;
 
-      return new Promise((resolve, reject) => {
+      return new Promise(async (resolve, reject) => {
         const buffer = new BufferList();
-        const socket = tls.connect(options, () => {
-          socket.write(message);
-        });
 
-        socket.once('timeout', () => {
-          socket.removeAllListeners();
-          socket.destroy();
-          reject(new MongoCryptError('KMS request timed out'));
-        });
+        let socket;
+        let rawSocket;
+
+        function destroySockets() {
+          for (const sock of [socket, rawSocket]) {
+            if (sock) {
+              sock.removeAllListeners();
+              sock.destroy();
+            }
+          }
+        }
 
-        socket.once('error', err => {
-          socket.removeAllListeners();
-          socket.destroy();
+        function ontimeout() {
+          destroySockets();
+          reject(new MongoCryptError('KMS request timed out'));
+        }
 
+        function onerror(err) {
+          destroySockets();
           const mcError = new MongoCryptError('KMS request failed');
           mcError.originalError = err;
           reject(mcError);
+        }
+
+        if (this.options.proxyOptions && this.options.proxyOptions.host) {
+          rawSocket = net.connect({
+            host: this.options.proxyOptions.host,
+            port: this.options.proxyOptions.port || 1080
+          });
+
+          rawSocket.on('timeout', ontimeout);
+          rawSocket.on('error', onerror);
+          try {
+            await once(rawSocket, 'connect');
+            options.socket = (
+              await SocksClient.createConnection({
+                existing_socket: rawSocket,
+                command: 'connect',
+                destination: { host: options.host, port: options.port },
+                proxy: {
+                  host: 'locahost',
+                  port: 0,
+                  type: 5,
+                  userId: this.options.proxyOptions.username,
+                  password: this.options.proxyOptions.username
+                }
+              })
+            ).socket;
+          } catch (err) {
+            return onerror(err);
+          }
+        }
+
+        socket = tls.connect(options, () => {
+          socket.write(message);
         });
 
+        socket.once('timeout', ontimeout);
+        socket.once('error', onerror);
+
         socket.on('data', data => {
           buffer.append(data);
           while (request.bytesNeeded > 0 && buffer.length) {

bindings/node/package.json

@@ -40,7 +40,8 @@
     "bindings": "^1.5.0",
     "bl": "^2.2.1",
     "node-addon-api": "^4.1.0",
-    "prebuild-install": "6.1.2"
+    "prebuild-install": "6.1.2",
+    "socks": "^2.6.1"
   },
   "devDependencies": {
     "bson": "^4.4.0",

bindings/node/test/stateMachine.test.js

@@ -1,39 +1,41 @@
 'use strict';
 
 const BSON = require('bson');
-const EventEmitter = require('events').EventEmitter;
+const { EventEmitter, once } = require('events');
+const net = require('net');
 const tls = require('tls');
 const expect = require('chai').expect;
 const sinon = require('sinon');
 const mongodb = require('mongodb');
 const StateMachine = require('../lib/stateMachine')({ mongodb }).StateMachine;
 
 describe('StateMachine', function() {
-  describe('kmsRequest', function() {
-    class MockRequest {
-      constructor(message, bytesNeeded) {
-        this._bytesNeeded = typeof bytesNeeded === 'number' ? bytesNeeded : 1024;
-        this._message = message;
-        this.endpoint = 'some.fake.host.com';
-        this._kmsProvider = 'aws';
-      }
-      get message() {
-        return this._message;
-      }
+  class MockRequest {
+    constructor(message, bytesNeeded) {
+      this._bytesNeeded = typeof bytesNeeded === 'number' ? bytesNeeded : 1024;
+      this._message = message;
+      this.endpoint = 'some.fake.host.com';
+      this._kmsProvider = 'aws';
+    }
 
-      get bytesNeeded() {
-        return this._bytesNeeded;
-      }
+    get message() {
+      return this._message;
+    }
 
-      get kmsProvider() {
-        return this._kmsProvider;
-      }
+    get bytesNeeded() {
+      return this._bytesNeeded;
+    }
 
-      addResponse(buffer) {
-        this._bytesNeeded -= buffer.length;
-      }
+    get kmsProvider() {
+      return this._kmsProvider;
+    }
+
+    addResponse(buffer) {
+      this._bytesNeeded -= buffer.length;
     }
+  }
 
+  describe('kmsRequest', function() {
     class MockSocket extends EventEmitter {
       constructor(callback) {
         super();
@@ -93,4 +95,55 @@ describe('StateMachine', function() {
       this.sinon.restore();
     });
   });
+
+  describe('Socks5 support', function() {
+    let socks5srv;
+    let hasTlsConnection;
+
+    beforeEach(async () => {
+      hasTlsConnection = false;
+      socks5srv = net.createServer(async(socket) => {
+        expect(await once(socket, 'data')).to.deep.equal([Buffer.from('05020002', 'hex')]);
+        socket.write(Buffer.from('0500', 'hex'));
+        expect(await once(socket, 'data')).to.deep.equal([Buffer.concat([
+          Buffer.from('0501000312', 'hex'),
+          Buffer.from('some.fake.host.com'),
+          Buffer.from('01bb', 'hex')
+        ])]);
+        socket.write(Buffer.from('0500007f0000010100', 'hex'));
+        expect((await once(socket, 'data'))[0][1]).to.equal(3); // TLS handshake version byte
+        hasTlsConnection = true;
+        socket.end();
+      });
+      socks5srv.listen(0);
+      await once(socks5srv, 'listening');
+    });
+
+    afterEach(() => {
+      socks5srv.close();
+    });
+
+    it('should create HTTPS connections through a Socks5 proxy', async function() {
+      const stateMachine = new StateMachine({
+        bson: BSON,
+        proxyOptions: {
+          host: 'localhost',
+          port: socks5srv.address().port,
+          username: 'foo',
+          password: 'bar'
+        }
+      });
+
+      const request = new MockRequest(Buffer.from('foobar'), 500);
+      try {
+        await stateMachine.kmsRequest(request);
+      } catch (err) {
+        expect(err.name).to.equal('MongoCryptError');
+        expect(err.originalError.code).to.equal('ECONNRESET');
+        expect(hasTlsConnection).to.equal(true);
+        return;
+      }
+      expect.fail('missed exception');
+    });
+  });
 });