Metadata.hs

-- | Stability: experimental
-- A function for decoding a [FIDO Alliance Metadata Service](https://fidoalliance.org/metadata/)
-- BLOB in order to be able to enforce a set of requirements on the authenticator
-- used, e.g. to only allow authenticators that have been
-- [FIDO certified](https://fidoalliance.org/certification/functional-certification/).
module Crypto.WebAuthn.Metadata
  ( metadataBlobToRegistry,
    Service.MetadataServiceRegistry,
  )
where

import qualified Crypto.WebAuthn.Metadata.Service.Processing as Service
import qualified Crypto.WebAuthn.Metadata.Service.Types as Service
import qualified Data.ByteString as BS
import qualified Data.Hourglass as HG
import Data.Text (Text)
import qualified Data.Text as Text

-- | Verifies, decodes and extracts a 'Service.MetadataServiceRegistry' from a
-- [FIDO Alliance Metadata Service](https://fidoalliance.org/metadata/) BLOB.
-- The result can be passed to 'Crypto.WebAuthn.Operation.Registration.verifyRegistrationResponse'.
metadataBlobToRegistry ::
  -- | A Metadata BLOB fetched from <https://mds.fidoalliance.org>
  BS.ByteString ->
  -- | The time at which it was fetched
  HG.DateTime ->
  -- | Either an error on a registry of metadata entries
  Either Text Service.MetadataServiceRegistry
metadataBlobToRegistry bytes now = do
  json <- case Service.jwtToJson bytes Service.fidoAllianceRootCertificate now of
    Left err -> Left $ Text.pack $ show err
    Right res -> pure res
  payload <- Service.jsonToPayload json
  pure $ Service.createMetadataRegistry $ Service.mpEntries payload