Does Stunnel support non-encrypt connection?

Question

1 question about Stunnel. I would like to use Stunnel as a FIX (Financial Information eXchange) gateway for internet, to support both SSL and non-SSL connection. Is Stunnel able to do without any encryption? I just had a try with plain socket but it looked Stunnel rejected the connection saying 'invalid protocol' or something.

Kwangtung

What exactly are you trying to achieve with a non-encrypted Stunnel? Are you after using SSL/TLS without encryption or are you after a simple TCP relay of some sort? – Potluck

Hi Bruno, what I want to do is just to run it as a gateway, route the incoming TCP msg to aonther ip/port. – Kwangtung

I've just voted to move this to SuperUser, since this isn't really a programming-related question. – Potluck

Answer 1

It's possible to use SSL/TLS without encryption using cipher suites with null encryption (e.g. TLS_RSA_WITH_NULL_SHA), which are normally disabled by default, but could be set via the ciphers option of Stunnel. However, you would still be using SSL/TLS, which isn't what you seem to be looking for.

It looks like you're more generally looking for what's usually called a TCP bouncer. You should be able to find a number of implementations around.

Potluck

Bruno, could you please recommend a solution of 'TCP bouncer'? I searched a lot, it looks few result with it. – Kwangtung

Not sure, it depends on your environment. There are multiple forms of "TCP bouncing": it can be done via a router similarly to "reverse NAT" solutions (e.g. via ipchains), via independent applications, or via SSH (which would also secure the section of the connection that's using SSH). – Potluck