replace base64-bytestring with base64 (#1065)

* replace base64-bytestring with base64

* minify

* use bytestring-0.10 compatible fork

PR pending...

* bump base64 fork with text compat

* move compat details to modules

* switch repo

* add back module

* cleanup

* minify

* clean imports

* rename

---------

Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>

src/Simplex/Messaging/Encoding/Base64.hs

@@ -0,0 +1,29 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+-- | Compatibility wrappers for base64 package, Base64 (padded) variant.
+module Simplex.Messaging.Encoding.Base64 where
+
+import qualified Data.Attoparsec.ByteString.Char8 as A
+import Data.Base64.Types (extractBase64)
+import Data.Bifunctor (first)
+import Data.ByteString.Base64 (decodeBase64Untyped, encodeBase64')
+import Data.ByteString.Char8 (ByteString)
+import qualified Data.ByteString.Char8 as B
+import qualified Data.Text as T
+
+encode :: ByteString -> ByteString
+encode = extractBase64 . encodeBase64'
+{-# INLINE encode #-}
+
+decode :: ByteString -> Either String ByteString
+decode = first T.unpack . decodeBase64Untyped
+{-# INLINE decode #-}
+
+base64P :: A.Parser ByteString
+base64P = do
+  str <- A.takeWhile1 (`B.elem` base64Alphabet)
+  pad <- A.takeWhile (== '=') -- correct amount of padding can be derived from str length
+  either (fail . T.unpack) pure $ decodeBase64Untyped (str <> pad)
+
+base64Alphabet :: ByteString
+base64Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"