Secure Tunnel V2 WebSocket Protocol support (#533)

* Secure Tunnel API Expansion

* Secure Tunnel V2 WebSocket Protocol support (Multiplexing)

Author: sbSteveK

README.md

@@ -23,6 +23,7 @@ __Jump To:__
 * [FAQ](./documents/FAQ.md)
 * [Giving Feedback and Contributions](#Giving-Feedback-and-Contributions)
 * [MQTT5 User Guide](./documents/MQTT5_Userguide.md)
+* [Secure Tunnel User Guide](./documents/Secure_Tunnel_Userguide.md)
 
 
 ## Installation

crt/aws-c-iot

@@ -0,0 +1,165 @@
+# Introduction
+When devices are deployed behind restricted firewalls at remote sites, you need a way to gain access to those devices for troubleshooting, configuration updates, and other operational tasks. Use secure tunneling to establish bidirectional communication to remote devices over a secure connection that is managed by AWS IoT. Secure tunneling does not require updates to your existing inbound firewall rules, so you can keep the same security level provided by firewall rules at a remote site.
+
+More information on the service and how to open, close, and manage secure tunnels can be found here: https://docs.aws.amazon.com/iot/latest/developerguide/secure-tunneling.html
+
+A sample is also provided and can be found here: https://github.com/aws/aws-iot-device-sdk-cpp-v2/tree/main/samples#secure-tunnel
+
+
+
+# Getting started with Secure Tunnels
+## How to Create a Secure Tunnel Client
+Once a Secure Tunnel builder has been created, it is ready to make a Secure Tunnel client. Something important to note is that once a Secure Tunnel client is built and finalized, the configuration is immutable and cannot be changed. Further modifications to the Secure Tunnel builder will not change the settings of already created Secure Tunnel clients.
+
+```cpp
+// Create Secure Tunnel Builder
+SecureTunnelBuilder builder = SecureTunnelBuilder(...);
+
+// Build Secure Tunnel Client
+std::shared_ptr<SecureTunnel> secureTunnel = builder.Build();
+
+if (secureTunnel == nullptr)
+{
+    fprintf(stdout, "Secure Tunnel creation failed.\n");
+    return -1;
+}
+
+// Start the secure tunnel connection
+if (!secureTunnel->Start())
+{
+    fprintf("Failed to start Secure Tunnel\n");
+    return -1;
+}
+```
+## Callbacks
+
+### OnConnectionSuccess
+When the Secure Tunnel Client successfully connects with the Secure Tunnel service, this callback will return the available (if any) service ids.
+
+### OnConnectionFailure
+When a WebSocket upgrade request fails to connect, this callback will return an error code.
+
+### OnConnectionShutdown
+When the WebSocket connection shuts down, this callback will be invoked.
+
+### OnSendDataComplete
+When a message has been completely written to the socket, this callback will be invoked.
+
+### OnMessageReceived
+When a message is received on an open Secure Tunnel stream, this callback will return the message.
+
+### OnStreamStarted
+When a stream is started by a Source connected to the Destination, the Destination will invoke this callback and return the stream information.
+
+### OnStreamStopped
+When an open stream is closed, this callback will be invoked and return the stopped stream's information.
+
+### OnSessionReset
+When the Secure Tunnel service requests the Secure Tunnel client fully reset, this callback is invoked.
+
+### OnStopped
+When the Secure Tunnel has reached a fully stopped state this callback is invoked.
+
+## Setting Secure Tunnel Callbacks
+The Secure Tunnel client uses callbacks to keep the user updated on its status and pass along relavant information. These can be set up using the Secure Tunnel builder's With functions.
+
+```cpp
+// Create Secure Tunnel Builder
+SecureTunnelBuilder builder = SecureTunnelBuilder(...);
+
+// Setting the onMessageReceived callback using the builder
+builder.WithOnMessageReceived([&](SecureTunnel *secureTunnel, const MessageReceivedEventData &eventData) {
+        {
+            std::shared_ptr<Message> message = eventData.message;
+            if (message->getServiceId().has_value()){
+                fprintf(
+                    stdout,
+                    "Message received on service id:'" PRInSTR "'\n",
+                    AWS_BYTE_CURSOR_PRI(message->getServiceId().value()));
+            }
+
+            if(message->getPayload().has_value()){
+                fprintf(
+                    stdout,
+                    "Message has payload:'" PRInSTR "'\n",
+                    AWS_BYTE_CURSOR_PRI(message->getPayload().value()));
+            }
+        }
+    });
+
+// Build Secure Tunnel Client
+std::shared_ptr<SecureTunnel> secureTunnel = builder.Build();
+
+if (secureTunnel == nullptr)
+{
+    fprintf(stdout, "Secure Tunnel creation failed.\n");
+    return -1;
+}
+
+// Start the secure tunnel connection
+if (!secureTunnel->Start())
+{
+    fprintf("Failed to start Secure Tunnel\n");
+    return -1;
+}
+
+// Messages received on a stream will now be printed to stdout.
+```
+
+# How to Start and Stop
+
+## Start
+Invoking `Start()` on the Secure Tunnel Client will put it into an active state where it recurrently establishes a connection to the configured Secure Tunnel endpoint using the provided [Client Access Token](https://docs.aws.amazon.com/iot/latest/developerguide/secure-tunneling-concepts.html). If a [Client Token](https://docs.aws.amazon.com/iot/latest/developerguide/secure-tunneling-concepts.html) is provided, the Secure Tunnel Client will use it. If a Client Token is not provided, the Secure Tunnel Client will automatically generate one for use on a reconnection attempts. The Client Token for any initial connection to the Secure Tunnel service **MUST** be unique. Reusing a Client Token from a previous connection will result in a failed connection to the Secure Tunnel Service.
+```cpp
+// Create Secure Tunnel Builder
+SecureTunnelBuilder builder = SecureTunnelBuilder(...);
+
+// Adding a client token to the builder
+String clientToken;
+builder.WithClientToken(clientToken.c_str());
+
+// Build Secure Tunnel Client
+std::shared_ptr<SecureTunnel> secureTunnel = builder.Build();
+
+if (secureTunnel == nullptr)
+{
+    fprintf(stdout, "Secure Tunnel creation failed.\n");
+    return -1;
+}
+
+// Start the secure tunnel connection
+if (!secureTunnel->Start())
+{
+    fprintf("Failed to start Secure Tunnel\n");
+    return -1;
+}
+```
+
+## Stop
+Invoking `Stop()` on the Secure Tunnel Client breaks the current connection (if any) and moves the client into an idle state.
+```cpp
+if(!secureTunnel->Stop()){
+    fprintf(stdout, "Failed to stop the Secure Tunnel connection session. Exiting..\n");
+}
+```
+
+# Secure Tunnel Operations
+
+## Send Message
+The SendMessage operation takes a description of the Message you wish to send and returns a success/failure in the synchronous logic that kicks off the Send Message operation. When the message is fully written to the socket, the OnSendDataComplete callback will be invoked.
+
+```cpp
+Crt::String serviceId_string = "ssh";
+Crt::String message_string = "any payload";
+
+ByteCursor serviceId = ByteCursorFromString(serviceId_string);
+ByteCursor payload = ByteCursorFromString(message_string);
+
+// Create Message
+std::shared_ptr<Message> message = std::make_shared<Message>();
+message->withServiceId(serviceId);
+message->withPayload(payload);
+
+// Send Message
+secureTunnel->SendMessage(message);
+```

crt/aws-crt-cpp

@@ -977,7 +977,7 @@ using a permanent certificate set, replace the paths specified in the `--cert` a
 
 ## Secure Tunnel
 
-This sample uses AWS IoT [Secure Tunneling](https://docs.aws.amazon.com/iot/latest/developerguide/secure-tunneling.html) Service to connect a destination and a source with each other through the AWS Secure Tunnel endpoint using access tokens.
+This sample uses AWS IoT [Secure Tunneling](https://docs.aws.amazon.com/iot/latest/developerguide/secure-tunneling.html) Service to connect a destination and a source with each other through the AWS Secure Tunnel endpoint using access tokens using the [V2WebSocketProtocol](https://github.com/aws-samples/aws-iot-securetunneling-localproxy/blob/main/V2WebSocketProtocolGuide.md). [Secure Tunnel Userguide](https://github.com/aws/aws-iot-device-sdk-cpp-v2/blob/main/documents/Secure_Tunnel_Userguide.md)
 
 Source: `samples/secure_tunneling/secure_tunnel`
 
@@ -986,17 +986,13 @@ Create a new secure tunnel in the AWS IoT console (https://console.aws.amazon.co
 Provide the necessary arguments along with the destination access token and start the sample in destination mode (default).
 
 ``` sh
-./secure_tunnel --endpoint <endpoint> --ca_file <path to root CA>
---cert <path to the certificate> --key <path to the private key>
---thing_name <thing name> --region <region> --access_token_file <path to destination access token>
+./secure_tunnel --region <region> --access_token_file <path to destination access token>
 ```
 
 Provide the necessary arguments along with the source access token and start a second sample in source mode by using the flag --localProxyModeSource.
 
 ``` sh
-./secure_tunnel --endpoint <endpoint> --ca_file <path to root CA>
---cert <path to the certificate> --key <path to the private key>
---thing_name <thing name> --region <region> --access_token_file <path to source access token>
+./secure_tunnel --region <region> --access_token_file <path to source access token>
 --localProxyModeSource
 ```