git-annex/Utility/MD5.hs
Joey Hess 426053cb6c
Corrected some license statements
In 40ecf58d4b I changed the license of code I
wrote from GPL to AGPL. But, two files containing code I wrote combined
with code by others were updated to say their license is AGPL, while in
fact part of it was (the code I wrote) but part remained under the original
license (the code written by others).

Remote/Ddar.hs is now changed entirely back to GPL 3.

Annex/DirHashes.hs stays AGPL, but I broke out Utility/MD5.hs with the code
not written by me, and corrected its license statement to GPL-2, which
is the actual version of the GPL included with the code in its original
distribution at http://www.cs.ox.ac.uk/people/ian.lynagh/md5/
2019-07-28 14:27:33 -04:00

23 lines
669 B
Haskell

{- modified version of MD5 from http://www.cs.ox.ac.uk/people/ian.lynagh/md5
-
- Copyright (C) 2001 Ian Lynagh
- License: GPL 2
-}
module Utility.MD5 where
import Data.Bits
import Data.Word
display_32bits_as_dir :: Word32 -> String
display_32bits_as_dir w = trim $ swap_pairs cs
where
-- Need 32 characters to use. To avoid inaverdently making
-- a real word, use letters that appear less frequently.
chars = ['0'..'9'] ++ "zqjxkmvwgpfZQJXKMVWGPF"
cs = map (\x -> getc $ (shiftR w (6*x)) .&. 31) [0..7]
getc n = chars !! fromIntegral n
swap_pairs (x1:x2:xs) = x2:x1:swap_pairs xs
swap_pairs _ = []
-- Last 2 will always be 00, so omit.
trim = take 6