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Diffstat (limited to 'src/Sproxy/Application/State.hs')
-rw-r--r-- | src/Sproxy/Application/State.hs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/Sproxy/Application/State.hs b/src/Sproxy/Application/State.hs new file mode 100644 index 0000000..29d9252 --- /dev/null +++ b/src/Sproxy/Application/State.hs @@ -0,0 +1,30 @@ +module Sproxy.Application.State ( + decode +, encode +) where + +import Data.ByteString (ByteString) +import Data.ByteString.Lazy (fromStrict, toStrict) +import Data.Digest.Pure.SHA (hmacSha1, bytestringDigest) +import qualified Data.ByteString.Base64 as Base64 +import qualified Data.Serialize as DS + + +-- FIXME: Compress / decompress ? + + +encode :: ByteString -> ByteString -> ByteString +encode key payload = Base64.encode . DS.encode $ (payload, digest key payload) + + +decode :: ByteString -> ByteString -> Either String ByteString +decode key d = do + (payload, dgst) <- DS.decode =<< Base64.decode d + if dgst /= digest key payload + then Left "junk" + else Right payload + + +digest :: ByteString -> ByteString -> ByteString +digest key payload = toStrict . bytestringDigest $ hmacSha1 (fromStrict key) (fromStrict payload) + |