Re: TCG TPM license issue

On Fri, 2026-01-23 at 11:02 +0100, Stefano Garzarella wrote:
> Hi all,
> it seems the license of the TCG TPM reference implementation that we
> are using to emulate the vTPM in SVSM is not exactly BSD but a
> variant of it.
> 
> For some distro, like Fedora, this could be an issue. See
> https://gitlab.com/fedora/legal/fedora-license-data/-/issues/716

The problem clause is a conditional statement about the origin of the
code and not part of the licence, so I don't believe it modifies the
BSD-2-Clause nature of the implementation in any way.

Additionally, just in the interest of fair dealing Fedora can't
disapprove of this this disclaimer in coconut, but perfectly fine with
it in another project they're already shipping:

https://packages.fedoraproject.org/pkgs/libtpms/libtpms/index.html

which has a slightly different form of the disclaimer (inherited
directly from the TCG) which seems to be a bit stronger in terms of
modifying the licence:

https://github.com/stefanberger/libtpms/blob/master/LICENSE

---
THE COPYRIGHT LICENSES SET FORTH ABOVE DO NOT REPRESENT ANY FORM OF
LICENSE OR WAIVER, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, WITH
RESPECT TO PATENT RIGHTS HELD BY TCG MEMBERS (OR OTHER THIRD PARTIES)
THAT MAY BE NECESSARY TO IMPLEMENT THIS SPECIFICATION OR
OTHERWISE. Contact TCG Administration
([email protected]) for information on specification
licensing rights available through TCG membership agreements.
---

However, I did ask and got word that apparently the TCG has already
modified its copyright IP policy not to require the patent disclaimer
in the code, so it's going to remove the language from the TPM
repository anyway.  I'm guessing that would mean the same problematic
clause can be removed from libtpms but you'll need to take that up with
upstream.

Regards,

James