module Codec.Binary.Base32Hex
( EncIncData(..)
, EncIncRes(..)
, encodeInc
, encode
, DecIncData(..)
, DecIncRes(..)
, decodeInc
, decode
, chop
, unchop
) where
import Codec.Binary.Util
import Control.Monad
import Data.Array
import Data.Bits
import Data.Maybe
import Data.Word
import qualified Data.Map as M
import qualified Codec.Binary.Base32 as Base32
_encMap =
[ (0, '0'), (1, '1'), (2, '2'), (3, '3'), (4, '4')
, (5, '5'), (6, '6'), (7, '7'), (8, '8'), (9, '9')
, (10, 'A'), (11, 'B'), (12, 'C'), (13, 'D'), (14, 'E')
, (15, 'F'), (16, 'G'), (17, 'H'), (18, 'I'), (19, 'J')
, (20, 'K'), (21, 'L'), (22, 'M'), (23, 'N'), (24, 'O')
, (25, 'P'), (26, 'Q'), (27, 'R'), (28, 'S'), (29, 'T')
, (30, 'U'), (31, 'V') ]
encodeArray :: Array Word8 Char
encodeArray = array (0, 32) _encMap
decodeMap :: M.Map Char Word8
decodeMap = M.fromList [(snd i, fst i) | i <- _encMap]
encodeInc :: EncIncData -> EncIncRes String
encodeInc e = eI [] e
where
enc5 [o1, o2, o3, o4, o5] = map (encodeArray !) [i1, i2, i3, i4, i5, i6, i7, i8]
where
i1 = o1 `shiftR` 3
i2 = (o1 `shiftL` 2 .|. o2 `shiftR` 6) .&. 0x1f
i3 = o2 `shiftR` 1 .&. 0x1f
i4 = (o2 `shiftL` 4 .|. o3 `shiftR` 4) .&. 0x1f
i5 = (o3 `shiftL` 1 .|. o4 `shiftR` 7) .&. 0x1f
i6 = o4 `shiftR` 2 .&. 0x1f
i7 = (o4 `shiftL` 3 .|. o5 `shiftR` 5) .&. 0x1f
i8 = o5 .&. 0x1f
eI [] EDone = EFinal []
eI [o1] EDone = EFinal (take 2 cs ++ "======")
where
cs = enc5 [o1, 0, 0, 0, 0]
eI [o1, o2] EDone = EFinal (take 4 cs ++ "====")
where
cs = enc5 [o1, o2, 0, 0, 0]
eI [o1, o2, o3] EDone = EFinal (take 5 cs ++ "===")
where
cs = enc5 [o1, o2, o3, 0, 0]
eI [o1, o2, o3, o4] EDone = EFinal (take 7 cs ++ "=")
where
cs = enc5 [o1, o2, o3, o4, 0]
eI lo (EChunk bs) = doEnc [] (lo ++ bs)
where
doEnc acc (o1:o2:o3:o4:o5:os) = doEnc (acc ++ enc5 [o1, o2, o3, o4, o5]) os
doEnc acc os = EPart acc (eI os)
encode :: [Word8] -> String
encode = encoder encodeInc
decodeInc :: DecIncData String -> DecIncRes String
decodeInc d = dI [] d
where
dec8 cs = let
ds = map (flip M.lookup decodeMap) cs
es@[e1, e2, e3, e4, e5, e6, e7, e8] = map fromJust ds
o1 = e1 `shiftL` 3 .|. e2 `shiftR` 2
o2 = e2 `shiftL` 6 .|. e3 `shiftL` 1 .|. e4 `shiftR` 4
o3 = e4 `shiftL` 4 .|. e5 `shiftR` 1
o4 = e5 `shiftL` 7 .|. e6 `shiftL` 2 .|. e7 `shiftR` 3
o5 = e7 `shiftL` 5 .|. e8
allJust = and . map isJust
in if allJust ds
then Just [o1, o2, o3, o4, o5]
else Nothing
dI [] DDone = DFinal [] []
dI lo DDone = DFail [] lo
dI lo (DChunk s) = doDec [] (lo ++ s)
where
doDec acc s@(c1:c2:'=':'=':'=':'=':'=':'=':cs) = maybe
(DFail acc s)
(\ bs -> DFinal (acc ++ take 1 bs) cs)
(dec8 [c1, c2, 'A', 'A', 'A', 'A', 'A', 'A'])
doDec acc s@(c1:c2:c3:c4:'=':'=':'=':'=':cs) = maybe
(DFail acc s)
(\ bs -> DFinal (acc ++ take 2 bs) cs)
(dec8 [c1, c2, c3, c4, 'A', 'A', 'A', 'A'])
doDec acc s@(c1:c2:c3:c4:c5:'=':'=':'=':cs) = maybe
(DFail acc s)
(\ bs -> DFinal (acc ++ take 3 bs) cs)
(dec8 [c1, c2, c3, c4, c5, 'A', 'A', 'A'])
doDec acc s@(c1:c2:c3:c4:c5:c6:c7:'=':cs) = maybe
(DFail acc s)
(\ bs -> DFinal (acc ++ take 4 bs) cs)
(dec8 [c1, c2, c3, c4, c5, c6, c7, 'A'])
doDec acc s@(c1:c2:c3:c4:c5:c6:c7:c8:cs) = maybe
(DFail acc s)
(\ bs -> doDec (acc ++ bs) cs)
(dec8 [c1, c2, c3, c4, c5, c6, c7, c8])
doDec acc s = DPart acc (dI s)
decode :: String
-> Maybe [Word8]
decode = decoder decodeInc
chop :: Int
-> String
-> [String]
chop = Base32.chop
unchop :: [String]
-> String
unchop = Base32.unchop