[Asterisk-Security] SRTP vs IPSEC

[Enzo Michelangeli]

----- Original Message ----- 
From: "Jeremy Jackson" <jerj at coplanar.net>
To: "Asterisk Security Discussion" <asterisk-security at lists.digium.com>
Sent: Wednesday, August 24, 2005 10:40 AM
Subject: Re: [Asterisk-Security] SRTP vs IPSEC


> Enzo Michelangeli wrote:
[...]
> >Why? Asterisk is GPL'd too...
> >
> >
> We all wish it was.

Well, the README file in the distribution says so, although it keeps open
the possibility of other types of licenses in addition to the GPL _only_
for the modules under Digium's copyright:

---------------
* LICENSING
  Asterisk is distributed under GNU General Public License and is also
available under alternative licenses negotiated directly with Digium, Inc.
If you obtained Asterisk under the GPL, then the GPL applies to all
loadable modules used on your system as well, except as defined below.

  Digium, Inc. (formerly Linux Support Services) retains copyright and/or
a
sufficient license to all components of the core Asterisk system, and
therefore
can grant, at its sole discretion, the ability for companies, individuals,
or
organizations to create proprietary or Open Source (but non-GPL'd) modules
which may be dynamically linked at runtime with the portions of Asterisk
which
fall under our copyright/license umbrella, or are distributed under more
flexible licenses than GPL.

  If you wish to use our code in other GPL programs, don't worry -- there
is no requirement that you provide the same exception in your GPL'd
products (although if you've written a module for Asterisk we would
strongly encourage you to make the same exception that we do).
[...]
---------------

This dual-licensing style is not uncommon, and I can't see any reason why
linking Asterisk with GPL'd code should create legal difficulties on
either side... The only problems may arise if licensees under
closed-source terms will want to use the GPL's SRTP module. In that case,
they will have to either develop their own, or negotiate terms with the
copyright holder of the GPL'd SRTP implementation (a copyright holder
_always_ retains the right of re-licensing his/her work under different
terms, GPL or not).

Enzo