Hi... Here is what I do
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1 - Client : BeginSend : "MESSAGE1"

2 -
a.Server receive "MESSAGE1" and ask to start TLS

b.Send MESSAGE: "START TLS"

3 - Client Receive : "START TLS"

4 - Client : ChangeSecurityProtocol( TLS )

5 - Client : EndSend "CallBack"

!! NullReferenceException

Why it is strange ?
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Server has completely receive client message, and send a response message to client.

The "EndSend" callback even AFTER we receive the server message !!

A solution :
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Class : SecureSocket
Method : EndSend(...)

I add this :

if (ti == null)
return base.EndSend(asyncResult)

and remove :

if (ti == null)
throw new ArgumentException();

Explaination:
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I cannot synchronise the Send, it has no sense !!! (Asynchrone Send is FASTER)

Then with this code, if we receive a "normal" IAsyncResult, we process it normally.



Please, tell me if it is correct ?