Sapphire.cpp -- Gpl compatible? DFSG-free?

[Dmitrijs Ledkovs <dmitrij.ledkov@gmail.com>]

In the source code of the package my team is managing there is this one file.

I'm wondering whether it is DFSG-free and weather GPL v2 only code can
link it with/(out) exception.

Here is the full copyright statement

/* sapphire.cpp -- the Saphire II stream cipher class.
   Dedicated to the Public Domain the author and inventor:
   (Michael Paul Johnson).  This code comes with no warranty.
   Use it at your own risk.
   Ported from the Pascal implementation of the Sapphire Stream
   Cipher 9 December 1994.
   Added hash pre- and post-processing 27 December 1994.
   Modified initialization to make index variables key dependent,
   made the output function more resistant to cryptanalysis,
   and renamed to Sapphire II 2 January 1995
*/

--
With best regards


Dmitrijs Ledkovs (for short Dima),
Ледков Дмитрий Юрьевич