Add: contributor agreement workflow (#1540)

* Add: contribution agreement template
* Add: readme for contribution agreement
* Change: mention contribution agreement in README.md

README.md

@@ -68,9 +68,9 @@ This project is maintained by [Greenbone AG](https://www.greenbone.net/).
 ## Contributing
 
 Your contributions are highly appreciated. Please [create a pull
-request](https://github.com/greenbone/openvas-scanner/pulls) on GitHub. Bigger
-changes need to be discussed with the development team via the [issues section
-at GitHub](https://github.com/greenbone/openvas-scanner/issues) first.
+request](https://github.com/greenbone/openvas-scanner/pulls) on GitHub.
+Remember to commit the contribution agreement as explained in RELICENSING folder with your first PR.
+Bigger changes should be discussed with the development team via the [issues section at GitHub](https://github.com/greenbone/openvas-scanner/issues) first.
 
 ## License
 

RELICENSE/README.md

@@ -0,0 +1,23 @@
+# openvas-scanner contribution agreement
+
+We want to relicense our code to `GPL-3.0-or-later` or `AGPL-3.0-or-later` in the future. Although most of the new code is licensed under `GPL-2.0-or-later` we want to make sure that no problems accure when relicensing. Your contributions are licensed under `MIT-0` and instantly relicensed to our currently used license. This means either `GPL-2.0-or-later` or `GPL-2.0`. Rust code is currently licensed with `GPL-2.0-or-later` per default. C code depends on the location and changes.
+
+Please read and commit the /template/template.txt as [Name].md in this folder with your first PR. Having a valid `git.user.name` and `git.user.email` is sufficient.
+
+Example usage:
+
+```
+# check with e.g. `git config --list` if you have a valid `user.name` and `user.email` set.
+$ git config --list
+    [email protected]
+    user.name=jane Doe
+    ....
+
+# Commit the template
+$ cd {path_to_openvas-scanner}/openvas-scanner/RELICENSE
+$ cp /template/template.txt JDoe.md
+$ git add JDoe.md
+$ git commit
+```
+
+Happy hacking!

RELICENSE/template/template.txt

@@ -0,0 +1,80 @@
+Thank you for your interest in the project openvas-scanner managed by Greenbone.
+In order for you to make Contributions now or in the future to this
+project, You agree to license your Contributions under the MIT-0 license (see below).
+Please note that You remain the copyright owner, and anyone receives the right to
+use your Contribution in proprietary and open source software without any
+attribution.
+
+..................
+
+MIT No Attribution (MIT-0)
+
+Copyright <YEAR> <COPYRIGHT HOLDER>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+.........................
+
+Please note that You remain the copyright owner, and anyone receives the
+right to use your Contribution in proprietary and open source software
+without attribution. However, we will include your name as a Contributor
+in our CREDITS list as long as your Contribution is used in the project
+openvas-scanner.
+
+"Contribution" shall mean any original work of authorship, including any
+modifications or additions to an existing work, that is submitted by you
+to Greenbone for inclusion in the project openvas-scanner.
+
+Greenbone requires that each Contribution you submit now or in the
+future to comply with the following commitments documented in the
+Developer Certificate of Origin (DCO) [https://developercertificate.org/]:
+
+........
+
+Developer Certificate of Origin
+
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+
+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.
+
+.....