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Re: Linux-libre 5.8 and beyond
From: |
Bengt Richter |
Subject: |
Re: Linux-libre 5.8 and beyond |
Date: |
Tue, 11 Aug 2020 00:39:31 +0200 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On +2020-08-09 18:17:48 -0400, Mark H Weaver wrote:
>
> Note that although base32 encodes 5 bits per character, the first
> character of a base32-encoded sha256 hash can only be 0 or 1, since
> there's only 1 bit remaining to encode after the other 255 bits have
> been encoded in the last 51 characters.
>
UIAM, that's only true for the nix flavor (which is default for guix hash, I
think)
of base32. Again UIAM, the nix view of a 256-bit sha256sum hash is
little-endian,
and shifts 5 bits out the bottom, as if with euclidean/ 32, and so winds up with
the 1 or 0 last, at the top.
I think all the others base32's shift 5 bits at a time from the big end, and
could have the full range 0-31 for the top digit, however translated to glyphs.
Which also means the last value on the right is a 1 or 0 in the top bit, valued
16 or 0.
Of course, different length digests may produce other remainder end values.
BTW, how did nix get such a weird alphabet for 0-31 ? Watermarking themselves?
:)
--
Regards,
Bengt Richter
Re: Linux-libre 5.8 and beyond, Leo Famulari, 2020/08/09
Re: Linux-libre 5.8 and beyond, Leo Famulari, 2020/08/25