Allow configurable audience claim (#975)

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #933, OpenAPI externals docs url to current version - @steve-chavez
 - #962, OpenAPI don't err on nonexistent schema - @steve-chavez
 - #954, make OpenAPI rpc output dependent on user privileges - @steve-chavez
+- #955, Support configurable aud claim - @statik
 
 ## [0.4.3.0] - 2017-09-06
 

app.json

@@ -43,6 +43,10 @@
       "required": false,
       "value": "false"
     },
+    "JWT_AUD": {
+      "description": "The audience that should be validated if the JWT token contains an aud claim",
+      "required": false
+    },
     "MAX_ROWS": {
       "description": "A hard limit to the number of rows PostgREST will fetch from a view, table, or stored procedure",
       "required": false

docker/Dockerfile

@@ -33,6 +33,7 @@ ENV PGRST_DB_URI= \
     PGRST_SERVER_PROXY_URI= \
     PGRST_JWT_SECRET= \
     PGRST_SECRET_IS_BASE64=false \
+    PGRST_JWT_AUD= \
     PGRST_MAX_ROWS= \
     PGRST_PRE_REQUEST=
 

docker/postgrest.conf

@@ -9,6 +9,7 @@ server-port = "$(PGRST_SERVER_PORT)"
 server-proxy-uri = "$(PGRST_SERVER_PROXY_URI)"
 jwt-secret = "$(PGRST_JWT_SECRET)"
 secret-is-base64 = "$(PGRST_SECRET_IS_BASE64)"
+jwt-aud = "$(PGRST_JWT_AUD)"
 
 max-rows = "$(PGRST_MAX_ROWS)"
 pre-request = "$(PGRST_PRE_REQUEST)"

src/PostgREST/App.hs

@@ -76,7 +76,7 @@ postgrest conf refDbStructure pool worker =
         response <- case userApiRequest (configSchema conf) req body of
           Left err -> return $ apiRequestError err
           Right apiRequest -> do
-            eClaims <- jwtClaims jwtSecret (toS $ iJWT apiRequest)
+            eClaims <- jwtClaims jwtSecret (configJwtAudience conf) (toS $ iJWT apiRequest)
 
             let authed = containsRole eClaims
                 handleReq = runWithClaims conf eClaims (app dbStructure conf) apiRequest

src/PostgREST/Auth.hs

@@ -39,16 +39,16 @@ data JWTAttempt = JWTInvalid JWTError
                 deriving (Eq, Show)
 
 {-|
-  Receives the JWT secret (from config) and a JWT and returns a map
+  Receives the JWT secret and audience (from config) and a JWT and returns a map
   of JWT claims.
 -}
-jwtClaims :: Maybe JWK -> BL.ByteString -> IO JWTAttempt
-jwtClaims _ "" = return $ JWTClaims M.empty
-jwtClaims secret payload =
+jwtClaims :: Maybe JWK -> Text -> BL.ByteString  -> IO JWTAttempt
+jwtClaims _ "" "" = return $ JWTClaims M.empty
+jwtClaims secret audience payload =
   case secret of
     Nothing -> return JWTMissingSecret
     Just jwk -> do
-      let validation = defaultJWTValidationSettings
+      let validation = set audiencePredicate (==  fromString audience) defaultJWTValidationSettings
       eJwt <- runExceptT $ do
         jwt <- decodeCompact payload
         validateJWSJWT validation jwk jwt

src/PostgREST/Config.hs

@@ -59,6 +59,7 @@ data AppConfig = AppConfig {
 
   , configJwtSecret         :: Maybe B.ByteString
   , configJwtSecretIsBase64 :: Bool
+  , configJwtAudience       :: Text
 
   , configPool              :: Int
   , configMaxRows           :: Maybe Integer
@@ -117,6 +118,7 @@ readOptions = do
           <*> (fromMaybe 3000 . join . fmap coerceInt <$> C.key "server-port")
           <*> (fmap encodeUtf8 . mfilter (/= "") <$> C.key "jwt-secret")
           <*> (fromMaybe False . join . fmap coerceBool <$> C.key "secret-is-base64")
+          <*> (fromMaybe "" <$> C.key "jwt-aud")
           <*> (fromMaybe 10 . join . fmap coerceInt <$> C.key "db-pool")
           <*> (join . fmap coerceInt <$> C.key "max-rows")
           <*> (mfilter (/= "") <$> C.key "pre-request")
@@ -177,6 +179,7 @@ readOptions = do
         |## (use "@filename" to load from separate file)
         |# jwt-secret = "foo"
         |# secret-is-base64 = false
+        |# jwt-aud = "your_audience_claim"
         |
         |## limit rows in response
         |# max-rows = 1000

test/Feature/AudienceJwtSecretSpec.hs

@@ -0,0 +1,44 @@
+module Feature.AudienceJwtSecretSpec where
+
+-- {{{ Imports
+import Test.Hspec
+import Test.Hspec.Wai
+import Network.HTTP.Types
+
+import SpecHelper
+import Network.Wai (Application)
+
+import Protolude hiding (get)
+-- }}}
+
+spec :: SpecWith Application
+spec = describe "test handling of aud claims in JWT" $ do
+
+  -- this test will stop working 9999999999s after the UNIX EPOCH
+  it "succeeds with jwt token containing with an audience claim" $ do
+    {-  This is the decoded contents of authHeaderJWT
+
+        {
+          "exp": 9999999999,
+          "role": "postgrest_test_author",
+          "id": "jdoe",
+          "aud": "youraudience"
+        }
+
+    -}
+    let auth = authHeaderJWT "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjk5OTk5OTk5OTksInJvbGUiOiJwb3N0Z3Jlc3RfdGVzdF9hdXRob3IiLCJpZCI6Impkb2UiLCJhdWQiOiJ5b3VyYXVkaWVuY2UifQ.fJ4tLKSmolWGWehWN20qiU9dMO-WY0RI2VvacL7-ZGo"
+    request methodGet "/authors_only" [auth] ""
+      `shouldRespondWith` 200
+
+  it "succeeds with jwt token that does not contain an audience claim" $ do
+    {- This is the decoded contents of authHeaderJWT
+
+        {
+          "exp": 9999999999,
+          "role": "postgrest_test_author",
+          "id": "jdoe"
+        }
+    -}
+    let auth = authHeaderJWT "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjk5OTk5OTk5OTksInJvbGUiOiJwb3N0Z3Jlc3RfdGVzdF9hdXRob3IiLCJpZCI6Impkb2UifQ.Dpss-QoLYjec5OTsOaAc3FNVsSjA89wACoV-0ra3ClA"
+    request methodGet "/authors_only" [auth] ""
+      `shouldRespondWith` 200

test/Main.hs

@@ -13,6 +13,7 @@ import Data.IORef
 import qualified Feature.AuthSpec
 import qualified Feature.AsymmetricJwtSpec
 import qualified Feature.BinaryJwtSecretSpec
+import qualified Feature.AudienceJwtSecretSpec
 import qualified Feature.ConcurrentSpec
 import qualified Feature.CorsSpec
 import qualified Feature.DeleteSpec
@@ -40,14 +41,15 @@ main = do
 
   result <- P.use pool $ getDbStructure "test"
   refDbStructure <- newIORef $ Just $ either (panic.show) id result
-  let withApp                = return $ postgrest (testCfg testDbConn)          refDbStructure pool $ pure ()
-      ltdApp                 = return $ postgrest (testLtdRowsCfg testDbConn)   refDbStructure pool $ pure ()
-      unicodeApp             = return $ postgrest (testUnicodeCfg testDbConn)   refDbStructure pool $ pure ()
-      proxyApp               = return $ postgrest (testProxyCfg testDbConn)     refDbStructure pool $ pure ()
-      noJwtApp               = return $ postgrest (testCfgNoJWT testDbConn)     refDbStructure pool $ pure ()
-      binaryJwtApp           = return $ postgrest (testCfgBinaryJWT testDbConn) refDbStructure pool $ pure ()
-      asymJwkApp             = return $ postgrest (testCfgAsymJWK testDbConn)   refDbStructure pool $ pure ()
-      nonexistentSchemaApp   = return $ postgrest (testNonexistentSchemaCfg testDbConn)   refDbStructure pool $ pure ()
+  let withApp              = return $ postgrest (testCfg testDbConn)            refDbStructure pool $ pure ()
+      ltdApp               = return $ postgrest (testLtdRowsCfg testDbConn)     refDbStructure pool $ pure ()
+      unicodeApp           = return $ postgrest (testUnicodeCfg testDbConn)     refDbStructure pool $ pure ()
+      proxyApp             = return $ postgrest (testProxyCfg testDbConn)       refDbStructure pool $ pure ()
+      noJwtApp             = return $ postgrest (testCfgNoJWT testDbConn)       refDbStructure pool $ pure ()
+      binaryJwtApp         = return $ postgrest (testCfgBinaryJWT testDbConn)   refDbStructure pool $ pure ()
+      audJwtApp            = return $ postgrest (testCfgAudienceJWT testDbConn) refDbStructure pool $ pure ()
+      asymJwkApp           = return $ postgrest (testCfgAsymJWK testDbConn)     refDbStructure pool $ pure ()
+      nonexistentSchemaApp = return $ postgrest (testNonexistentSchemaCfg testDbConn)   refDbStructure pool $ pure ()
 
   let reset = resetDb testDbConn
   hspec $ do
@@ -73,6 +75,10 @@ main = do
     beforeAll_ reset . before binaryJwtApp $
       describe "Feature.BinaryJwtSecretSpec" Feature.BinaryJwtSecretSpec.spec
 
+    -- this test runs with a binary JWT secret and an audience claim
+    beforeAll_ reset . before audJwtApp $
+      describe "Feature.AudienceJwtSecretSpec" Feature.AudienceJwtSecretSpec.spec
+
     -- this test runs with asymmetric JWK
     beforeAll_ reset . before asymJwkApp $
       describe "Feature.AsymmetricJwtSpec" Feature.AsymmetricJwtSpec.spec

test/SpecHelper.hs

@@ -68,7 +68,7 @@ _baseCfg :: AppConfig
 _baseCfg =  -- Connection Settings
   AppConfig mempty "postgrest_test_anonymous" Nothing "test" "localhost" 3000
             -- Jwt settings
-            (Just $ encodeUtf8 "reallyreallyreallyreallyverysafe") False
+            (Just $ encodeUtf8 "reallyreallyreallyreallyverysafe") False ""
             -- Connection Modifiers
             10 Nothing (Just "test.switch_role")
             -- Debug Settings
@@ -95,6 +95,13 @@ testCfgBinaryJWT testDbConn = (testCfg testDbConn) {
       "cmVhbGx5cmVhbGx5cmVhbGx5cmVhbGx5dmVyeXNhZmU="
   }
 
+testCfgAudienceJWT :: Text -> AppConfig
+testCfgAudienceJWT testDbConn = (testCfg testDbConn) {
+    configJwtSecret = Just . B64.decodeLenient $
+      "cmVhbGx5cmVhbGx5cmVhbGx5cmVhbGx5dmVyeXNhZmU=",
+    configJwtAudience = "youraudience"
+  }
+
 testCfgAsymJWK :: Text -> AppConfig
 testCfgAsymJWK testDbConn = (testCfg testDbConn) {
     configJwtSecret = Just $ encodeUtf8