Add proxy support for iot connections (#1195)

Author: desokroshan

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## [Release 2.16.3](https://github.com/aws/aws-sdk-android/releases/tag/release_v2.16.3)
 
+### New Features
+
+- **AWS IoT**
+  - Added proxy support for connecting to AWS IoT via Keystore over port 8883
+
 ### Bug Fixes
 
 - **AWS Mobile Client**

aws-android-sdk-iot/src/main/java/com/amazonaws/mobileconnectors/iot/AWSIotMqttManager.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2010-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -181,6 +181,12 @@ public class AWSIotMqttManager {
      */
     private final String endpoint;
 
+    /**
+     * This is the hostname and port of the proxy, if any, to be used for connecting to AWS IoT
+     */
+    private String proxyHost;
+    private int proxyPort;
+
     /**
      * Turning on/off metrics collection. By default metrics collection is enabled.
      * Client must call this to set metrics collection to false before calling connect in order to turn
@@ -735,10 +741,32 @@ public void connectUsingALPN(KeyStore keyStore,
         connect(keyStore, 443, statusCallback);
     }
 
+    /**
+     * Initializes the MQTT session and connects to the specified MQTT server
+     * using certificate and private key in keystore on port 8883 via the proxy specified by a
+     * host and port combination. Keystore should be created using
+     * {@link com.amazonaws.mobileconnectors.iot.AWSIotKeystoreHelper} to setup the
+     * certificate and key aliases as expected by the underlying socket helper library.
+     *
+     * @param keyStore A keystore containing an keystore with a certificate and
+     *            private key. Use IotKeystoreHelper to get keystore.
+     * @param proxyHost hostname of the proxy
+     * @param proxyPort proxy port number
+     * @param statusCallback When new MQTT session status is received the
+     *            function of callback will be called with new connection
+     *            status.
+     */
+    public void connectWithProxy(KeyStore keyStore, final String proxyHost, final int proxyPort,
+                                 final AWSIotMqttClientStatusCallback statusCallback) {
+        this.proxyHost = proxyHost;
+        this.proxyPort = proxyPort;
+        connect(keyStore, 8883, statusCallback);
+    }
+
     /**
      * Initializes the MQTT session and connects to the specified MQTT server
      * using certificate and private key in keystore on port 8883. Keystore should be created
-     * using IotKeystoreHelper to setup the certificate and key aliases as
+     * using {@link com.amazonaws.mobileconnectors.iot.AWSIotKeystoreHelper} to setup the certificate and key aliases as
      * expected by the underlying socket helper library.
      *
      * @param keyStore A keystore containing an keystore with a certificate and
@@ -800,7 +828,10 @@ private void connect(KeyStore keyStore, int portNumber, final AWSIotMqttClientSt
                 mqttClient = new MqttAsyncClient(mqttBrokerURL, mqttClientId, new MemoryPersistence());
             }
 
-            final SocketFactory socketFactory = AWSIotSslUtility.getSocketFactoryWithKeyStore(keyStore, portNumber);
+            final SocketFactory socketFactory = (proxyHost != null) ?
+                    AWSIotSslUtility.getSocketFactoryWithKeyStoreAndProxy(keyStore, portNumber, proxyHost, proxyPort):
+                    AWSIotSslUtility.getSocketFactoryWithKeyStore(keyStore, portNumber) ;
+
             final MqttConnectOptions options = new MqttConnectOptions();
 
             if (mqttLWT != null) {