private bool SendEHello()
{
IAsyncResult result = EHelloCommand.BeginSend(_connection, _connection._client.clientDomain, s_sendEHelloCallback, this);
if (result.CompletedSynchronously)
{
_connection._extensions = EHelloCommand.EndSend(result);
_connection.ParseExtensions(_connection._extensions);
// If we already have a TlsStream, this is the second EHLO cmd
// that we sent after TLS handshake compelted. So skip TLS and
// continue with Authenticate.
if (_connection._networkStream is TlsStream)
{
Authenticate();
return(true);
}
if (_connection.EnableSsl)
{
if (!_connection._serverSupportsStartTls)
{
// Either TLS is already established or server does not support TLS
if (!(_connection._networkStream is TlsStream))
{
throw new SmtpException(string.Format(Strings.MailServerDoesNotSupportStartTls));
}
}
SendStartTls();
}
else
{
Authenticate();
}
return(true);
}
return(false);
}
private static void SendEHelloCallback(IAsyncResult result)
{
if (!result.CompletedSynchronously)
{
ConnectAndHandshakeAsyncResult thisPtr = (ConnectAndHandshakeAsyncResult)result.AsyncState;
try
{
try
{
thisPtr._connection._extensions = EHelloCommand.EndSend(result);
thisPtr._connection.ParseExtensions(thisPtr._connection._extensions);
// If we already have a SSlStream, this is the second EHLO cmd
// that we sent after TLS handshake compelted. So skip TLS and
// continue with Authenticate.
if (thisPtr._connection._networkStream is TlsStream)
{
thisPtr.Authenticate();
return;
}
}
catch (SmtpException e)
{
if ((e.StatusCode != SmtpStatusCode.CommandUnrecognized) &&
(e.StatusCode != SmtpStatusCode.CommandNotImplemented))
{
throw;
}
if (!thisPtr.SendHello())
{
return;
}
}
if (thisPtr._connection.EnableSsl)
{
if (!thisPtr._connection._serverSupportsStartTls)
{
// Either TLS is already established or server does not support TLS
if (!(thisPtr._connection._networkStream is TlsStream))
{
throw new SmtpException(Strings.MailServerDoesNotSupportStartTls);
}
}
thisPtr.SendStartTls();
}
else
{
thisPtr.Authenticate();
}
}
catch (Exception e)
{
thisPtr.InvokeCallback(e);
}
}
}
