olm/CONTRIBUTING.md

Contributing code to libolm

To contribute code to this library, the preferred way is to clone the git repository, create a git patch series (for example via git format-patch --stdout origin/master), and send this by email to olm@matrix.org.

Naturally, you must be willing to license your contributions under the same license as the project itself - in this case, Apache Software License v2 (see LICENSE).

Sign off

In order to have a concrete record that your contribution is intentional and you agree to license it under the same terms as the project's license, we've adopted the same lightweight approach that the Linux Kernel, Docker, and many other projects use: the DCO (Developer Certificate of Origin). This is a simple declaration that you wrote the contribution or otherwise have the right to contribute it to Matrix::

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

If you agree to this for your contribution, then all that's needed is to include the line in your commits or covering email::

Signed-off-by: Your Name <your@email.example.org>

...using your real name; unfortunately pseudonyms and anonymous contributions can't be accepted. Git makes this trivial - just use the -s flag when you do git commit, having first set user.name and user.email git configs (which you should have done anyway :)