Re: Proposal: Remove MKCRYPTO_RC5

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Fri, May 05, 2017 at 05:49:39PM +0000, Taylor R Campbell wrote:
> - It is (still!) patented in the United States, so it has only ever
> been a default-off option that we go to extra work to implement.

This part isn't clear to me. According to
http://jce.iaik.at/sic/Sales/Patent_Issues_Algorithms#RC5
there are three possible patents relevant to RC5. Looking at the
details and comparing with other sources, 5,724,428 is the main patent.
5,835,600 might be relevant, 6,269,163 is clearly RC6 (and talking about
RC5 quite a bit). Of those, '428 was filed on Nov 1, 1995 and Apr 21,
1997.

According to:
https://www.uspto.gov/patent/laws-and-regulations/patent-term-calculator#heading-5
for patents filed after June 7, 1995, the term ends twenty years after
the initial filing date. As such, both patents would seem to have
expired.

Based on that, I would suggest to drop the option and just include RC5
unconditionally.

Joerg