{- Copyright © 2007 Magnus Therning
-
- This file is part of dataenc.
-
- Dataenc is free software: you can redistribute it and/or modify it under
- the terms of the GNU Lesser General Public License as published by the
- Free Software Foundation, either version 3 of the License, or (at your
- option) any later version.
-
- Dataenc is distributed in the hope that it will be useful, but WITHOUT
- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with dataenc. If not, see
-}
-- | Base64Url module.
--
-- Implemented as specified in RFC 4648
-- ().
module Codec.Binary.Base64Url
( encode
, decode
, decode'
, chop
, unchop
) where
import Data.Maybe
import Data.Word
import qualified Codec.Binary.Base64 as Base64
-- {{{1 encode
-- | Encode data.
encode :: [Word8]
-> String
encode os = let
swapUrlChar c = case c of
'+' -> '-'
'/' -> '_'
_ -> c
in map swapUrlChar $ Base64.encode os
-- {{{1 decode
-- | Decode data (lazy).
decode' :: String
-> [Maybe Word8]
decode' = let
unSwapUrlChar c = case c of
'-' -> '+'
'_' -> '/'
_ -> c
in Base64.decode' . map unSwapUrlChar
-- | Decode data (strict).
decode :: String
-> Maybe [Word8]
decode = sequence . decode'
-- {{{1 chop
-- | Chop up a string in parts.
--
-- See 'Base64.chop' in "Base64" for more details.
chop :: Int -- ^ length of individual lines
-> String
-> [String]
chop = Base64.chop
-- {{{1 unchop
-- | Concatenate the strings into one long string.
--
-- See 'Base64.unchop' in "Codec.Binary.Base64" for more details.
unchop :: [String]
-> String
unchop = Base64.unchop