graphql-engine/server/src-lib/Hasura/Server/Auth/JWT.hs

373 lines
13 KiB
Haskell

module Hasura.Server.Auth.JWT
( processJwt
, RawJWT
, JWTConfig (..)
, JWTCtx (..)
, JWKSet (..)
, JWTClaimsFormat (..)
, updateJwkRef
, jwkRefreshCtrl
, defaultClaimNs
) where
import Control.Arrow (first)
import Control.Exception (try)
import Control.Lens
import Control.Monad (when)
import Crypto.JWT
import Data.IORef (IORef, modifyIORef, readIORef)
import Data.List (find)
import Data.Time.Clock (NominalDiffTime, UTCTime,
diffUTCTime, getCurrentTime)
import Data.Time.Format (defaultTimeLocale, parseTimeM)
import Network.URI (URI)
import Hasura.HTTP
import Hasura.Logging (Logger (..))
import Hasura.Prelude
import Hasura.RQL.Types
import Hasura.Server.Auth.JWT.Internal (parseHmacKey, parseRsaKey)
import Hasura.Server.Auth.JWT.Logging
import Hasura.Server.Utils (bsToTxt, diffTimeToMicro,
userRoleHeader)
import qualified Control.Concurrent as C
import qualified Data.Aeson as A
import qualified Data.Aeson.Casing as A
import qualified Data.Aeson.TH as A
import qualified Data.ByteString.Lazy as BL
import qualified Data.ByteString.Lazy.Char8 as BLC
import qualified Data.CaseInsensitive as CI
import qualified Data.HashMap.Strict as Map
import qualified Data.String.Conversions as CS
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Network.HTTP.Client as HTTP
import qualified Network.HTTP.Types as HTTP
import qualified Network.Wreq as Wreq
newtype RawJWT = RawJWT BL.ByteString
data JWTClaimsFormat
= JCFJson
| JCFStringifiedJson
deriving (Show, Eq)
$(A.deriveJSON A.defaultOptions { A.sumEncoding = A.ObjectWithSingleField
, A.constructorTagModifier = A.snakeCase . drop 3
} ''JWTClaimsFormat)
data JWTConfig
= JWTConfig
{ jcType :: !T.Text
, jcKeyOrUrl :: !(Either JWK URI)
, jcClaimNs :: !(Maybe T.Text)
, jcAudience :: !(Maybe T.Text)
, jcClaimsFormat :: !(Maybe JWTClaimsFormat)
-- , jcIssuer :: !(Maybe T.Text)
} deriving (Show, Eq)
data JWTCtx
= JWTCtx
{ jcxKey :: !(IORef JWKSet)
, jcxClaimNs :: !(Maybe T.Text)
, jcxAudience :: !(Maybe T.Text)
, jcxClaimsFormat :: !JWTClaimsFormat
} deriving (Eq)
instance Show JWTCtx where
show (JWTCtx _ nsM audM cf) =
show ["<IORef JWKSet>", show nsM, show audM, show cf]
data HasuraClaims
= HasuraClaims
{ _cmAllowedRoles :: ![RoleName]
, _cmDefaultRole :: !RoleName
} deriving (Show, Eq)
$(A.deriveJSON (A.aesonDrop 3 A.snakeCase) ''HasuraClaims)
allowedRolesClaim :: T.Text
allowedRolesClaim = "x-hasura-allowed-roles"
defaultRoleClaim :: T.Text
defaultRoleClaim = "x-hasura-default-role"
defaultClaimNs :: T.Text
defaultClaimNs = "https://hasura.io/jwt/claims"
-- | create a background thread to refresh the JWK
jwkRefreshCtrl
:: (MonadIO m)
=> Logger
-> HTTP.Manager
-> URI
-> IORef JWKSet
-> NominalDiffTime
-> m ()
jwkRefreshCtrl lggr mngr url ref time =
void $ liftIO $ C.forkIO $ do
C.threadDelay $ diffTimeToMicro time
forever $ do
res <- runExceptT $ updateJwkRef lggr mngr url ref
mTime <- either (const $ return Nothing) return res
C.threadDelay $ maybe (60 * aSecond) diffTimeToMicro mTime
where
aSecond = 1000 * 1000
-- | Given a JWK url, fetch JWK from it and update the IORef
updateJwkRef
:: ( MonadIO m
, MonadError T.Text m)
=> Logger
-> HTTP.Manager
-> URI
-> IORef JWKSet
-> m (Maybe NominalDiffTime)
updateJwkRef (Logger logger) manager url jwkRef = do
let options = wreqOptions manager []
res <- liftIO $ try $ Wreq.getWith options $ show url
resp <- either logAndThrowHttp return res
let status = resp ^. Wreq.responseStatus
respBody = resp ^. Wreq.responseBody
when (status ^. Wreq.statusCode /= 200) $ do
let urlT = T.pack $ show url
respBodyT = Just $ CS.cs respBody
errMsg = "non-200 response on fetching JWK from: " <> urlT
httpErr = Just (JwkRefreshHttpError (Just status) urlT Nothing respBodyT)
logAndThrow errMsg httpErr
jwkset <- either (\e -> logAndThrow (T.pack e) Nothing) return . A.eitherDecode $ respBody
liftIO $ modifyIORef jwkRef (const jwkset)
let mExpiresT = resp ^? Wreq.responseHeader "Expires"
forM mExpiresT $ \expiresT -> do
let expiresE = parseTimeM True defaultTimeLocale timeFmt $ CS.cs expiresT
expires <- either (`logAndThrow` Nothing) return expiresE
currTime <- liftIO getCurrentTime
return $ diffUTCTime expires currTime
where
logAndThrow :: (MonadIO m, MonadError T.Text m) => T.Text -> Maybe JwkRefreshHttpError -> m a
logAndThrow err httpErr = do
liftIO $ logger $ mkJwkRefreshLog err httpErr
throwError err
logAndThrowHttp :: (MonadIO m, MonadError T.Text m) => HTTP.HttpException -> m a
logAndThrowHttp err = do
let httpErr = JwkRefreshHttpError Nothing (T.pack $ show url)
(Just $ HttpException err) Nothing
errMsg = "error fetching JWK: " <> T.pack (show err)
logAndThrow errMsg (Just httpErr)
timeFmt = "%a, %d %b %Y %T GMT"
-- | Process the request headers to verify the JWT and extract UserInfo from it
processJwt
:: ( MonadIO m
, MonadError QErr m)
=> JWTCtx
-> HTTP.RequestHeaders
-> Maybe RoleName
-> m (UserInfo, Maybe UTCTime)
processJwt jwtCtx headers mUnAuthRole =
maybe withoutAuthZHeader withAuthZHeader mAuthZHeader
where
mAuthZHeader = find (\h -> fst h == CI.mk "Authorization") headers
withAuthZHeader (_, authzHeader) =
processAuthZHeader jwtCtx headers $ BL.fromStrict authzHeader
withoutAuthZHeader = do
unAuthRole <- maybe missingAuthzHeader return mUnAuthRole
return $ (, Nothing) $
mkUserInfo unAuthRole $ mkUserVars $ hdrsToText headers
missingAuthzHeader =
throw400 InvalidHeaders "Missing Authorization header in JWT authentication mode"
processAuthZHeader
:: ( MonadIO m
, MonadError QErr m)
=> JWTCtx
-> HTTP.RequestHeaders
-> BLC.ByteString
-> m (UserInfo, Maybe UTCTime)
processAuthZHeader jwtCtx headers authzHeader = do
-- try to parse JWT token from Authorization header
jwt <- parseAuthzHeader
-- verify the JWT
claims <- liftJWTError invalidJWTError $ verifyJwt jwtCtx $ RawJWT jwt
let claimsNs = fromMaybe defaultClaimNs $ jcxClaimNs jwtCtx
claimsFmt = jcxClaimsFormat jwtCtx
expTimeM = fmap (\(NumericDate t) -> t) $ claims ^. claimExp
-- see if the hasura claims key exist in the claims map
let mHasuraClaims = Map.lookup claimsNs $ claims ^. unregisteredClaims
hasuraClaimsV <- maybe claimsNotFound return mHasuraClaims
-- get hasura claims value as an object. parse from string possibly
hasuraClaims <- parseObjectFromString claimsFmt hasuraClaimsV
-- filter only x-hasura claims and convert to lower-case
let claimsMap = Map.filterWithKey (\k _ -> T.isPrefixOf "x-hasura-" k)
$ Map.fromList $ map (first T.toLower)
$ Map.toList hasuraClaims
HasuraClaims allowedRoles defaultRole <- parseHasuraClaims claimsMap
let role = getCurrentRole defaultRole
when (role `notElem` allowedRoles) currRoleNotAllowed
let finalClaims =
Map.delete defaultRoleClaim . Map.delete allowedRolesClaim $ claimsMap
-- transform the map of text:aeson-value -> text:text
metadata <- decodeJSON $ A.Object finalClaims
return $ (, expTimeM) $ mkUserInfo role $ mkUserVars $ Map.toList metadata
where
parseAuthzHeader = do
let tokenParts = BLC.words authzHeader
case tokenParts of
["Bearer", jwt] -> return jwt
_ -> malformedAuthzHeader
parseObjectFromString claimsFmt jVal =
case (claimsFmt, jVal) of
(JCFStringifiedJson, A.String v) ->
either (const $ claimsErr $ strngfyErr v) return
$ A.eitherDecodeStrict $ T.encodeUtf8 v
(JCFStringifiedJson, _) ->
claimsErr "expecting a string when claims_format is stringified_json"
(JCFJson, A.Object o) -> return o
(JCFJson, _) ->
claimsErr "expecting a json object when claims_format is json"
strngfyErr v = "expecting stringified json at: '"
<> fromMaybe defaultClaimNs (jcxClaimNs jwtCtx)
<> "', but found: " <> v
claimsErr = throw400 JWTInvalidClaims
-- see if there is a x-hasura-role header, or else pick the default role
getCurrentRole defaultRole =
let userRoleHeaderB = CS.cs userRoleHeader
mUserRole = snd <$> find (\h -> fst h == CI.mk userRoleHeaderB) headers
in maybe defaultRole (RoleName . bsToTxt) mUserRole
decodeJSON val = case A.fromJSON val of
A.Error e -> throw400 JWTInvalidClaims ("x-hasura-* claims: " <> T.pack e)
A.Success a -> return a
liftJWTError :: (MonadError e' m) => (e -> e') -> ExceptT e m a -> m a
liftJWTError ef action = do
res <- runExceptT action
either (throwError . ef) return res
invalidJWTError e =
err400 JWTInvalid $ "Could not verify JWT: " <> T.pack (show e)
malformedAuthzHeader =
throw400 InvalidHeaders "Malformed Authorization header"
currRoleNotAllowed =
throw400 AccessDenied "Your current role is not in allowed roles"
claimsNotFound = do
let claimsNs = fromMaybe defaultClaimNs $ jcxClaimNs jwtCtx
throw400 JWTInvalidClaims $ "claims key: '" <> claimsNs <> "' not found"
-- parse x-hasura-allowed-roles, x-hasura-default-role from JWT claims
parseHasuraClaims
:: (MonadError QErr m)
=> A.Object -> m HasuraClaims
parseHasuraClaims claimsMap = do
let mAllowedRolesV = Map.lookup allowedRolesClaim claimsMap
allowedRolesV <- maybe missingAllowedRolesClaim return mAllowedRolesV
allowedRoles <- parseJwtClaim (A.fromJSON allowedRolesV) errMsg
let mDefaultRoleV = Map.lookup defaultRoleClaim claimsMap
defaultRoleV <- maybe missingDefaultRoleClaim return mDefaultRoleV
defaultRole <- parseJwtClaim (A.fromJSON defaultRoleV) errMsg
return $ HasuraClaims allowedRoles defaultRole
where
missingAllowedRolesClaim =
let msg = "JWT claim does not contain " <> allowedRolesClaim
in throw400 JWTRoleClaimMissing msg
missingDefaultRoleClaim =
let msg = "JWT claim does not contain " <> defaultRoleClaim
in throw400 JWTRoleClaimMissing msg
errMsg _ = "invalid " <> allowedRolesClaim <> "; should be a list of roles"
parseJwtClaim :: (MonadError QErr m) => A.Result a -> (String -> Text) -> m a
parseJwtClaim res errFn =
case res of
A.Success val -> return val
A.Error e -> throw400 JWTInvalidClaims $ errFn e
-- | Verify the JWT against given JWK
verifyJwt
:: ( MonadError JWTError m
, MonadIO m
)
=> JWTCtx
-> RawJWT
-> m ClaimsSet
verifyJwt ctx (RawJWT rawJWT) = do
key <- liftIO $ readIORef $ jcxKey ctx
jwt <- decodeCompact rawJWT
t <- liftIO getCurrentTime
verifyClaimsAt config key t jwt
where
audCheck aud = maybe True (== (T.pack . show) aud) $ jcxAudience ctx
config = defaultJWTValidationSettings audCheck
-- | Parse from a json string like:
-- | `{"type": "RS256", "key": "<PEM-encoded-public-key-or-X509-cert>"}`
-- | to JWTConfig
instance A.FromJSON JWTConfig where
parseJSON = A.withObject "JWTConfig" $ \o -> do
keyType <- o A..: "type"
mRawKey <- o A..:? "key"
claimNs <- o A..:? "claims_namespace"
aud <- o A..:? "audience"
jwkUrl <- o A..:? "jwk_url"
isStrngfd <- o A..:? "claims_format"
case (mRawKey, jwkUrl) of
(Nothing, Nothing) -> fail "key and jwk_url both cannot be empty"
(Just _, Just _) -> fail "key, jwk_url both cannot be present"
(Just rawKey, Nothing) -> do
key <- parseKey keyType rawKey
return $ JWTConfig keyType (Left key) claimNs aud isStrngfd
(Nothing, Just url) ->
return $ JWTConfig keyType (Right url) claimNs aud isStrngfd
where
parseKey keyType rawKey =
case keyType of
"HS256" -> runEither $ parseHmacKey rawKey 256
"HS384" -> runEither $ parseHmacKey rawKey 384
"HS512" -> runEither $ parseHmacKey rawKey 512
"RS256" -> runEither $ parseRsaKey rawKey
"RS384" -> runEither $ parseRsaKey rawKey
"RS512" -> runEither $ parseRsaKey rawKey
-- TODO: support ES256, ES384, ES512, PS256, PS384
_ -> invalidJwk ("Key type: " <> T.unpack keyType <> " is not supported")
runEither = either (invalidJwk . T.unpack) return
invalidJwk msg = fail ("Invalid JWK: " <> msg)