[stunnel-users] Stunnel License

Michal Trojnara Michal.Trojnara at mobi-com.net
Wed Sep 24 16:52:30 CEST 2008

"Bansal, Gaurav (Gaurav)" <gbansal at avaya.com> wrote:
> We are planning to use Stunnel to encrypt traffic between Apache mod_jk
> and AJP connector of JBoss Tomcat. 

Using stunnel does not create a derivative work.  GPL license does not
restrict the way you *use* stunnel.  It only restricts the way you
distribute it.

> It seems that Stunnel uses OpenSSL APIs. Since Stunnel is available
> under GPL license, the license terms prevents us from using Stunnel in
> our product since it exposes OpenSSL which is also available under GPL
> license.

Your product "exposes OpenSSL"?  I'm not sure what you mean.
AFAIK OpenSSL is not available under GPL license.

> I would like to know if there is also a commercial license available for
> stunnel? I would appreciate if you can throw pointers on how to package
> Stunnel with a commercial product.

You can package stunnel with a commercial product as long as it does not
create a derivative work.  Roughly speaking creating derivative work is
linking your code against stunnel.  See GPL license for the detailed

Yes - commercial licenses are available, but it looks like you don't need

> We would distribute stunnel binary along with our product. Given the
> scenario I have mentioned do you foresee legal problems in usage of
> stunnel.

Just make sure to distribute stunnel source and its license along with your

> Specifically I am concerned if Stunnel states that compiling, linking,
> and/or using OpenSSL is allowed

Stunnel license allows linking with OpenSSL.  See:

Best regards,

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