SslStream error: Stream was not writable

Question

I'm facing a strange error. Following code is always throwing exception (System.ArgumentException "Stream was not writable"):

TcpClient socket = new TcpClient();
socket.Connect("serverIp", serverPort);
//wrap networkstream with ssl 
SslStream sslStream = new SslStream(socket.GetStream(),false); 

stream.ReadTimeout = 5000;
stream.WriteTimeout = 5000;

//following line throws System.ArgumentException "Stream was not writable"
var writer = new BinaryWriter(sslStream); 
writer.Write(abMessage, nStart, nLength);
writer.Flush();

'sslStream' object canWrite and canRead properties are always 'false'.

Obviously, I have Googled, and searched in many forums, but, I always found that same code which is not working for me.

How can I fix this exception?

Answer 1

Once you create a SslStream (on top of a TcpClient) you should handshake the ssl connection. For this, you will use some of the methods available in the SslStream type:

• AuthenticateAsClient (several overloads)
• AuthenticateAsServer (several overloads)

(or they async variants BeginAuthenticateAs...)

Without using this handshaking methods the SslStream is not really setup and you won't be able to read or write from/to the network stream.

Which methods to use (AuthenticateAsClient or AuthenticateAsServer) is specific to your implementation and the desired usage of the SSL Stream.