Services,Tests: create HS streams on demand (#10)

There are multiple usecases when you need multiple
streams for your communication with HS client (e.g
sending multiple http requests), this was not supported
before and this commit fixes that.

Author: aarani

NOnion.Tests/HiddenServicesTests.cs

@@ -106,7 +106,8 @@ public async Task BrowseFacebookOverHS()
             using TorClient torClient = await TorClient.BootstrapWithGithubAsync(cachePath);
 
             var serviceClient = await TorServiceClient.ConnectAsync(torClient, "facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion");
-            var httpClient = new TorHttpClient(serviceClient.GetStream(), "facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion");
+            var stream = await serviceClient.GetStreamAsync();
+            var httpClient = new TorHttpClient(stream, "facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion");
 
             try
             {
@@ -131,8 +132,8 @@ public async Task BrowseFacebookOverHSWithTLS()
             using TorClient torClient = await TorClient.BootstrapWithGithubAsync(cachePath);
 
             var serviceClient = await TorServiceClient.ConnectAsync(torClient, "facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion:443");
-
-            var sslStream = new SslStream(serviceClient.GetStream(), true, (sender, cert, chain, sslPolicyErrors) => true);
+            var stream = await serviceClient.GetStreamAsync();
+            var sslStream = new SslStream(stream, true, (sender, cert, chain, sslPolicyErrors) => true);
             await sslStream.AuthenticateAsClientAsync(string.Empty, null, SslProtocols.Tls12, false);
 
             var httpClientOverSslStream = new TorHttpClient(sslStream, "www.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion");
@@ -185,7 +186,7 @@ public async Task EstablishAndCommunicateOverHSConnectionOnionStyle()
             var clientSide =
                 Task.Run(async () => {
                     var serviceClient = await TorServiceClient.ConnectAsync(torClient, host.ExportUrl());
-                    var stream = serviceClient.GetStream();
+                    var stream = await serviceClient.GetStreamAsync();
                     var lengthBytes = new byte[sizeof(int)];
                     await ReadExact(stream, lengthBytes, 0, lengthBytes.Length);
                     var length = BitConverter.ToInt32(lengthBytes);

NOnion/Services/TorServiceClient.fs

@@ -24,11 +24,21 @@ type TorServiceClient =
         {
             TorClient: TorClient
             RendezvousCircuit: TorCircuit
-            Stream: TorStream
+            Port: int
         }
 
     member self.GetStream() =
-        self.Stream
+        async {
+            // We can't use the "use" keyword since this stream needs
+            // to outlive this function.
+            let serviceStream = new TorStream(self.RendezvousCircuit)
+            do! serviceStream.ConnectToService self.Port |> Async.Ignore
+
+            return serviceStream
+        }
+
+    member self.GetStreamAsync() =
+        self.GetStream() |> Async.StartAsTask
 
     static member ConnectAsync (client: TorClient) (url: string) =
         TorServiceClient.Connect client url |> Async.StartAsTask
@@ -475,16 +485,11 @@ type TorServiceClient =
                     Async.Parallel [ introduceJob; rendezvousJoin ]
                     |> Async.Ignore
 
-                // We can't use the "use" keyword since this stream needs
-                // to outlive this function.
-                let serviceStream = new TorStream(rendezvousCircuit)
-                do! serviceStream.ConnectToService port |> Async.Ignore
-
                 return
                     {
                         TorClient = client
                         RendezvousCircuit = rendezvousCircuit
-                        Stream = serviceStream
+                        Port = port
                     }
             | _ ->
                 return

README.md

@@ -71,7 +71,7 @@ To connect to a hidden service using the Tor network, use the folowing command:
 let onionAddress = "facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion"
 
 let! serviceClient = TorServiceClient.Connect torClient onionAddress
-let stream = serviceClient.GetStream()
+let! stream = serviceClient.GetStream()
 ```
 Now, utilize the stream just like any other `System.IO.Stream`:
 ```