Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 12 Jan 2012 06:02:03 +0100
From: magnum <>
Subject: Re: copyright and license statements

On 01/11/2012 05:36 AM, Solar Designer wrote:
> When you make non-trivial changes to source files that I or someone else
> wrote, you become a copyright holder to those derived works.  So, yes,
> you can claim copyright, and I (and/or other authors) remain copyright
> holders as well.  You don't have to document what exactly your copyright
> applies to (which portions of the source file), but doing so is helpful.

I'll revise my statements. Here is an example:

 /*  HTTP Digest access authentication patch for john
  * Written by Romain Raboin - romain.raboin at
+ * OMP and intrinsics support: Copyright magnum 2012 and hereby
+ * released to the general public under the following terms:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, is permitted.

The original file had no statements at all, but my added statements just
applies to my changes. Does this make sense?

> However, for some other source files I think that would be problematic.
> For example, I am uncomfortable about lifting the GPL restrictions from
> rules.c for everyone at once because that file may be of (more) interest
> to (potential) proprietary password cracker programs.  I'd like to
> retain the right to issue such non-GPL licenses to them explicitly.  If
> you simply add your copyright statement to that file, which you should
> given your contributions to it in jumbo so far, then I am stuck with
> GPLv2, not being able to re-license the file in the future (neither for
> everyone at once nor for specific companies, etc.) without coordinating
> with you (which may even involve paperwork each time we're talking
> re-licensing for a specific company).  I see the following ways to
> resolve this for such source files:
> 1. Move your non-trivial contributions to separate (new) source files
> such that you can unambiguously apply your copyright statement and our
> standard permissive cut-down BSD license just to those.  Modify the
> original file (such as rules.c) in trivial ways only - e.g., adding
> calls into functions found in your new file.

This is optimal but it's too complicated. Typically I would hack away
until things are good. Then I would need to revert everything and move
it to another file. I don't think it's gonna happen in reality.

> 2. Don't retain your copyright to your changes to shared files, but
> instead transfer copyright either to me or to a legal entity that will
> be the copyright holder for JtR - perhaps to Openwall, Inc.  IIRC, this
> is the approach that e.g. the Nmap project is using (with copyright for
> contributions transferred to Insecure.Com LLC).  You will continue to be
> credited as an author of those files anyway, but not be a copyright
> holder.  (Authorship and copyright are distinct things.)

This is fine with me. Could this too be accomplished with just a
standard text that I add in the top comments? Ideally, there should be
an example of such a text on the licensing wiki page!

Another example, here is the current NT_fmt comments:

 /* NTLM patch for john (performance improvement)
  * Written by Alain Espinosa <alainesp at> in 2007.  No copyright
  * is claimed, and the software is hereby placed in the public domain.
  * In case this attempt to disclaim copyright and place the software in the
  * public domain is deemed null and void, then the software is
  * Copyright (c) 2007 Alain Espinosa and it is hereby released to the
  * general public under the following terms:
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted.
  * There's ABSOLUTELY NO WARRANTY, express or implied.
  * (This is a heavily cut-down "BSD license".)
+ * UTF-8 support and performance tweaks by magnum 2011, same terms as
+ *

I did not want to repeat the same text... so does this "same terms as
above" make sense? Or should I change to this:

  * Written by Alain Espinosa <alainesp at> in 2007 and
  * modified by magnum in 2011.  No copyright is claimed, and the

Two files I'm notoriously unsure of are rc4.h and rc4.c. I could place a
copyright in them but it would seem silly. Unless you have a better idea
I think I'll leave them as-is.


Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.