{-# LANGUAGE OverloadedStrings #-} -- | -- Module : Data.PEM.Writer -- License : BSD-style -- Maintainer : Vincent Hanquez <vincent@snarc.org> -- Stability : experimental -- Portability : portable -- module Data.PEM.Writer ( pemWriteLBS , pemWriteBS ) where import Data.PEM.Types import Data.ByteString (ByteString) import qualified Data.ByteString as B import qualified Data.ByteString.Char8 as BC import qualified Data.ByteString.Lazy as L import qualified Data.ByteString.Base64 as Base64 -- | write a PEM structure to a builder pemWrite :: PEM -> L.ByteString pemWrite pem = L.fromChunks $ ([begin,header]++section++[end]) where begin = B.concat ["-----BEGIN ", sectionName, "-----\n"] end = B.concat ["-----END ", sectionName, "-----\n" ] section :: [ByteString] section = map encodeLine $ splitChunks $ pemContent pem header :: ByteString header = if null $ pemHeader pem then B.empty else B.concat ((concatMap toHeader (pemHeader pem)) ++ ["\n"]) toHeader :: (String, ByteString) -> [ByteString] toHeader (k,v) = [ BC.pack k, ":", v, "\n" ] -- expect only ASCII. need to find a type to represent it. sectionName = BC.pack $ pemName pem encodeLine l = Base64.encode l `B.append` "\n" splitChunks b | B.length b > 48 = let (x,y) = B.splitAt 48 b in x : splitChunks y | otherwise = [b] -- | convert a PEM structure to a bytestring pemWriteBS :: PEM -> ByteString pemWriteBS = B.concat . L.toChunks . pemWrite -- | convert a PEM structure to a lazy bytestring pemWriteLBS :: PEM -> L.ByteString pemWriteLBS = pemWrite