IDEA License

[David Smith]

On 03/26/13 10:30, Jan Chaloupecky wrote:
> Sorry, I sent the last mail only to Hubert.
> 
> 
> I was saying that Squeeze does not have in any of its repositories the
> versions that support IDEA:
> 
> Max version of GnuPG  is 1.4.12
> http://packages.debian.org/search?keywords=gnupg&searchon=names&exact=1&suite=all&section=all
> Max version of libgcrypt is 1.5.1 
> http://packages.debian.org/search?keywords=libgcrypt11&searchon=names&exact=1&suite=all&section=all
> 
> So in other words, I can  have IDEA support in Debian Squeeze only when
> I compile myself either the extension for GPG 1 or libgcrypt for GPG 2.
> 
> Compiling and shipping IDEA means that I have to provide the sources of
> my software, correct?

Not necessarily.  If you write your own implementation of IDEA, you can
release it under any license you like.

If you include libgcrypt in your software, then it depends on how you
use it.  libgcrypt appears to be licensed under either GPL or LGPL[1],
so if you dynamically link against a separately-compiled libgcrypt
library, then you don't have to release your source because you can use
libgcrypt under the LGPL.

You can ship your own software and an LGPL-licensed library together
(e.g. in a tarfile), provided that the LGPL-licensed stuff is easily
separable from the proprietary stuff (i.e. in an independant library
which contains *only* LGPL code).

You do still have to include in your shipment information to state that
it includes libgcrypt licensed under the LGPL, and provide facilities
for your "customers" to get access to the libgcrypt source code.  If you
make any changes to the libgcrypt code to use for your application, then
you must make the source code for those changes available.

If you statically link libgcrypt into your software (i.e. compile it in
to the binary), then it is no longer easily separable from the
proprietary code, so you must release the source code to your software,
and furthermore, you cannot prevent anyone copying, modifying and
distributing your software and/or source code.

Again, IANAL, get your own professional legal advice, etc...

[1] http://directory.fsf.org/wiki/Libgcrypt