Botbuilder-samples: You have to specify TLS version during create WebSocketSharp.WebSocket in C# sample code.

[micli]

My issue is about DirectLine sample code of BotBuilder SDK for .NET, which is located at:
Samples/blob/master/core-DirectLineWebSockets/DirectLineClient

SDK platform is .NET

URL of Code Sample

https://github.com/Microsoft/BotBuilder-Samples/blob/master/CSharp/core-DirectLineWebSockets/DirectLineClient/Program.cs#L40

Problem Description

When I use above code to create a WebSocket to connect DirectLine I always get below error:
WebSocketSharp.WebSocketException: An error has occurred during a TLS handshake. ---> System.NotSupportedException: The requested security protocol is not supported.
at System.Net.SecurityProtocol.ThrowOnNotAllowed(SslProtocols protocols, Boolean allowNone)
at System.Net.Security.SslStream.AuthenticateAsClient(String targetHost, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, Boolean checkCertificateRevocation)
at WebSocketSharp.WebSocket.setClientStream()
--- End of inner exception stack trace ---
at WebSocketSharp.WebSocket.setClientStream()
at WebSocketSharp.WebSocket.doHandshake()
at WebSocketSharp.WebSocket.connect()

Actually, the root cause is web server of DirectLine service forced TLS v1.2 but WebSocketSharp doesn't specified yet.

How to fix

Add below line after created WebSocketSharp.WebSocket object:
// You have to specify TLS version to 1.2 or connection will be failed in handshake. WebSocketClient.SslConfiguration.EnabledSslProtocols = System.Security.Authentication.SslProtocols.Tls12;

[EricDahlvang]

Would you like to submit a PR to add this code to the sample?

[micli]

OK, I will do it soon.

[sgellock]

Let's make sure we take the PR in the v3 branch

[CoHealer]

@EricDahlvang, to get the PR ready.

[EricDahlvang]

Closing since this was apparently already merged: https://github.com/Microsoft/BotBuilder-Samples/pull/281

https://github.com/Microsoft/BotBuilder-Samples/blob/v3-sdk-samples/CSharp/core-DirectLineWebSockets/DirectLineClient/Program.cs#L44