Add basic-auth data types to servant core

servant/src/Servant/API.hs

@@ -29,6 +29,9 @@ module Servant.API (
   -- * Actual endpoints, distinguished by HTTP method
   module Servant.API.Verbs,
 
+  -- * Authentication
+  module Servant.API.BasicAuth,
+
   -- * Content Types
   module Servant.API.ContentTypes,
   -- | Serializing and deserializing types based on @Accept@ and
@@ -51,6 +54,7 @@ module Servant.API (
   ) where
 
 import           Servant.API.Alternative     ((:<|>) (..))
+import           Servant.API.BasicAuth       (BasicAuth,BasicAuthData(..))
 import           Servant.API.Capture         (Capture)
 import           Servant.API.ContentTypes    (Accept (..), FormUrlEncoded,
                                               FromFormUrlEncoded (..), JSON,

servant/src/Servant/API/BasicAuth.hs

@@ -0,0 +1,29 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE KindSignatures     #-}
+{-# LANGUAGE PolyKinds          #-}
+module Servant.API.BasicAuth where
+
+import           Data.ByteString (ByteString)
+import           Data.Typeable (Typeable)
+import           GHC.TypeLits  (Symbol)
+
+
+-- | Combinator for <https://tools.ietf.org/html/rfc2617#section-2 Basic Access Authentication>.
+--
+-- *IMPORTANT*: Only use Basic Auth over HTTPS! Credentials are not hashed or
+-- encrypted. Note also that because the same credentials are sent on every
+-- request, Basic Auth is not as secure as some alternatives. Further, the
+-- implementation in servant-server does not protect against some types of
+-- timing attacks.
+--
+-- In Basic Auth, username and password are base64-encoded and transmitted via
+-- the @Authorization@ header. Handshakes are not required, making it
+-- relatively efficient.
+data BasicAuth (realm :: Symbol)
+  deriving (Typeable)
+
+-- | A simple datatype to hold data required to decorate a request
+data BasicAuthData = BasicAuthData { basicAuthUsername :: !ByteString
+                                   , basicAuthPassword :: !ByteString
+                                   }