biscuit-servant: Servant support for the Biscuit security token

[ bsd3, library, security ] [ Propose Tags ]

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Dependencies base (>=4.7 && <5), biscuit-haskell (==0.2.*), bytestring (==0.10.*), mtl (==2.2.*), servant-server (==0.18.*), text (==1.2.*), wai (==3.2.*) [details]
License BSD-3-Clause
Copyright 2021 Clément Delafargue
Author Clément Delafargue
Category Security
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Source repo head: git clone
Uploaded by clementd at 2022-01-14T15:15:41Z
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Readme for biscuit-servant-

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biscuit-servant 🤖 Hackage

Servant combinators to enable biscuit validation in your API trees


type AppM = WithAuthorizer Handler
type API = RequireBiscuit :> ProtectedAPI

-- /users
-- /users/:userId
type ProtectedAPI =
  "users" :> ( Get '[JSON] [User]
             :<|> Capture "userId" Int :> Get '[JSON] User
app :: PublicKey -> Application
app pk = serveWithContext @API Proxy (genBiscuitCtx pk) server

server :: Server API
server biscuit =
  let handlers = userListHandler :<|> singleUserHandler
      handleAuth =
        handleBiscuit biscuit
        -- `allow if right("admin");` will be the first policy
        -- for every endpoint.
        -- Policies added by endpoints (or sub-apis) will tried after this one.
        . withPriorityAuthorizer [authorizer|allow if right("admin");|]
        -- `deny if true;` will be the last policy for every endpoint.
        -- Policies added by endpoints (or sub-apis) will tried before this one.
        . withFallbackAuthorizer [authorizer|deny if true;|]
  in hoistServer @ProtectedAPI Proxy handleAuth handlers

allUsers :: [User]
allUsers = [ User 1 "Danielle" "George"
           , User 2 "Albert" "Einstein"

userListHandler :: AppM [User]
userListHandler = withAuthorizer [authorizer|allow if right("userList")|]
  $ pure allUsers

singleUserHandler :: Int -> AppM User
singleUserHandler uid =
  withAuthorizer [authorizer|allow if right("getUser", ${uid})|] $
  let user = find (\user -> userId user == uid) allUsers
   in maybe (throwError error404) (\user -> pure user) user