Initial support for JWE

Partial support for JWE encode and decode.  Basic use is now possible
both for encryption and decryption.  Both GCM and CPC modes work for
encrypt, decrypt is CPC only for now.  For algorithms, RSA-OAEP works
both ways.  Deflate support is still missing, which is stated as
mandatory for RFC 7516.  Compact serialization and deserialization
work.

JWEs' one ciphertext for potentially multiple recipients has been
modeled with the same type variable usage that JWS uses for
General/Flattened/Compact divide.  CEK wrapping and unwrapping, and
ciphertext generation and decode are represented as two stages of
functions for each step.

More future work: JSON serializations likely still need more
attention.  Crypto.JOSE.Header may need some expanding to model shared
and non-shared unprotected headers and what lenses to expose for JWEs
needs consideration since arbitrary modifications may lead to invalid
JWE data.

src/Crypto/JOSE/Error.hs

@@ -120,6 +120,7 @@ data Error
  | JWSNoSignatures
  -- ^ 'AllValidated' policy active, and there were no signatures on object
  -- that matched the allowed algorithms
+ | JWEIntegrityFailed
  deriving (Eq, Show)
 makeClassyPrisms ''Error
 

src/Crypto/JOSE/JWA/JWE.hs

@@ -23,6 +23,14 @@ JSON Web Encryption data types specified under JSON Web Algorithms.
 module Crypto.JOSE.JWA.JWE
  ( Enc(..)
  , AlgWithParams(..)
+ , AlgOnly(..)
+ , SimpleAlg(..)
+ , ECDHESAlg(..)
+ , AESGCMAlg(..)
+ , PBES2Alg(..)
+ , algType
+ , algOnly
+ , knownAlgsMsg
  , AESGCMParameters(AESGCMParameters)
  , ECDHParameters(ECDHParameters)
  , PBES2Parameters(PBES2Parameters)
@@ -37,53 +45,98 @@ import Crypto.JOSE.Types.Internal (insertToObject)
 
 import Data.Aeson
 import qualified Data.Aeson.KeyMap as M
+import qualified Data.Text as Text
 
 
 -- | RFC 7518 §4. Cryptographic Algorithms for Key Management
 --
-data AlgWithParams
+data SimpleAlg
  = RSA1_5
  | RSA_OAEP
  | RSA_OAEP_256
  | A128KW
  | A192KW
  | A256KW
  | Dir
- | ECDH_ES ECDHParameters
- | ECDH_ES_A128KW ECDHParameters
- | ECDH_ES_A192KW ECDHParameters
- | ECDH_ES_A256KW ECDHParameters
- | A128GCMKW AESGCMParameters
- | A192GCMKW AESGCMParameters
- | A256GCMKW AESGCMParameters
- | PBES2_HS256_A128KW PBES2Parameters
- | PBES2_HS384_A192KW PBES2Parameters
- | PBES2_HS512_A256KW PBES2Parameters
  deriving (Eq, Show)
 
+data ECDHESAlg
+ = ECDH_ES
+ | ECDH_ES_A128KW
+ | ECDH_ES_A192KW
+ | ECDH_ES_A256KW
+ deriving (Eq, Show)
+
+data AESGCMAlg
+ = A128GCMKW
+ | A192GCMKW
+ | A256GCMKW
+ deriving (Eq, Show)
+
+data PBES2Alg
+ = PBES2_HS256_A128KW
+ | PBES2_HS384_A192KW
+ | PBES2_HS512_A256KW
+ deriving (Eq, Show)
+
+data AlgWithParams
+ = SimpleAlg SimpleAlg
+ | ECDHESAlg ECDHESAlg ECDHParameters
+ | AESGCMAlg AESGCMAlg AESGCMParameters
+ | PBES2Alg PBES2Alg PBES2Parameters
+ deriving (Eq, Show)
+
+data AlgOnly
+ = SimpleAlgOnly SimpleAlg
+ | ECDHESAlgOnly ECDHESAlg
+ | AESGCMAlgOnly AESGCMAlg
+ | PBES2AlgOnly PBES2Alg
+ deriving (Eq, Show)
+
+algType :: Text.Text -> Either () AlgOnly
+algType t = case t of
+ "RSA1_5" -> simple RSA1_5
+ "RSA-OAEP" -> simple RSA_OAEP
+ "RSA-OAEP-256" -> simple RSA_OAEP_256
+ "A128KW" -> simple A128KW
+ "A192KW" -> simple A192KW
+ "A256KW" -> simple A256KW
+ "dir" -> simple Dir
+ "ECDH-ES" -> ecdh ECDH_ES
+ "ECDH-ES+A128KW" -> ecdh ECDH_ES_A128KW
+ "ECDH-ES+A192KW" -> ecdh ECDH_ES_A192KW
+ "ECDH-ES+A256KW" -> ecdh ECDH_ES_A256KW
+ "A128GCMKW" -> aesgcm A128GCMKW
+ "A192GCMKW" -> aesgcm A192GCMKW
+ "A256GCMKW" -> aesgcm A256GCMKW
+ "PBES2-HS256+A128KW" -> pbes2 PBES2_HS256_A128KW
+ "PBES2-HS384+A192KW" -> pbes2 PBES2_HS384_A192KW
+ "PBES2-HS512+A256KW" -> pbes2 PBES2_HS512_A256KW
+ _ -> Left ()
+ where
+ simple = pure . SimpleAlgOnly
+ ecdh = pure . ECDHESAlgOnly
+ aesgcm = pure . AESGCMAlgOnly
+ pbes2 = pure . PBES2AlgOnly
+
+algOnly :: AlgWithParams -> AlgOnly
+algOnly (SimpleAlg a) = SimpleAlgOnly a
+algOnly (ECDHESAlg a _) = ECDHESAlgOnly a
+algOnly (AESGCMAlg a _) = AESGCMAlgOnly a
+algOnly (PBES2Alg a _) = PBES2AlgOnly a
+
 instance FromJSON AlgWithParams where
  parseJSON = withObject "Encryption alg and params" $ \o ->
- case M.lookup "alg" o of
+ case algType . (\x -> case x of String t -> t ; _ -> "") <$> M.lookup "alg" o of
  Nothing -> fail "\"alg\" parameter is required"
- Just "RSA1_5" -> pure RSA1_5
- Just "RSA-OAEP" -> pure RSA_OAEP
- Just "RSA-OAEP-256" -> pure RSA_OAEP_256
- Just "A128KW" -> pure A128KW
- Just "A192KW" -> pure A192KW
- Just "A256KW" -> pure A256KW
- Just "dir" -> pure Dir
- Just "ECDH-ES" -> ECDH_ES <$> parseJSON (Object o)
- Just "ECDH-ES+A128KW" -> ECDH_ES_A128KW <$> parseJSON (Object o)
- Just "ECDH-ES+A192KW" -> ECDH_ES_A192KW <$> parseJSON (Object o)
- Just "ECDH-ES+A256KW" -> ECDH_ES_A256KW <$> parseJSON (Object o)
- Just "A128GCMKW" -> A128GCMKW <$> parseJSON (Object o)
- Just "A192GCMKW" -> A192GCMKW <$> parseJSON (Object o)
- Just "A256GCMKW" -> A256GCMKW <$> parseJSON (Object o)
- Just "PBES2-HS256+A128KW" -> PBES2_HS256_A128KW <$> parseJSON (Object o)
- Just "PBES2-HS384+A192KW" -> PBES2_HS384_A192KW <$> parseJSON (Object o)
- Just "PBES2-HS512+A256KW" -> PBES2_HS512_A256KW <$> parseJSON (Object o)
- _ -> fail $ "unrecognised value; expected: "
- ++ "[\"RSA1_5\",\"RSA-OAEP\",\"RSA-OAEP-256\",\"A128KW\",\"A192KW\",\"A256KW\",\"dir\",\"ECDH-ES\",\"ECDH-ES+A128KW\",\"ECDH-ES+A192KW\",\"ECDH-ES+A256KW\",\"A128GCMKW\",\"A192GCMKW\",\"A256GCMKW\",\"PBES2-HS256+A128KW\",\"PBES2-HS384+A128KW\",\"PBES2-HS512+A128KW\"]"
+ Just (Right (SimpleAlgOnly a)) -> pure $ SimpleAlg a
+ Just (Right (ECDHESAlgOnly a)) -> ECDHESAlg a <$> parseJSON (Object o)
+ Just (Right (AESGCMAlgOnly a)) -> AESGCMAlg a <$> parseJSON (Object o)
+ Just (Right (PBES2AlgOnly a)) -> PBES2Alg a <$> parseJSON (Object o)
+ _ -> fail $ "unrecognised value; expected: " ++ knownAlgsMsg
+
+knownAlgsMsg :: String
+knownAlgsMsg = "[\"RSA1_5\",\"RSA-OAEP\",\"RSA-OAEP-256\",\"A128KW\",\"A192KW\",\"A256KW\",\"dir\",\"ECDH-ES\",\"ECDH-ES+A128KW\",\"ECDH-ES+A192KW\",\"ECDH-ES+A256KW\",\"A128GCMKW\",\"A192GCMKW\",\"A256GCMKW\",\"PBES2-HS256+A128KW\",\"PBES2-HS384+A128KW\",\"PBES2-HS512+A128KW\"]"
 
 algObject :: Value -> Value
 algObject s = object [("alg", s)]
@@ -92,23 +145,27 @@ algWithParamsObject :: ToJSON a => a -> Value -> Value
 algWithParamsObject a s = insertToObject "alg" s (toJSON a)
 
 instance ToJSON AlgWithParams where
- toJSON RSA1_5 = algObject "RSA1_5"
- toJSON RSA_OAEP = algObject "RSA-OAEP"
- toJSON RSA_OAEP_256 = algObject "RSA-OAEP-256"
- toJSON A128KW = algObject "A128KW"
- toJSON A192KW = algObject "A192KW"
- toJSON A256KW = algObject "A256KW"
- toJSON Dir = algObject "Dir"
- toJSON (ECDH_ES params) = algWithParamsObject params "ECDH-ES"
- toJSON (ECDH_ES_A128KW params) = algWithParamsObject params "ECDH-ES+A128KW"
- toJSON (ECDH_ES_A192KW params) = algWithParamsObject params "ECDH-ES+A192KW"
- toJSON (ECDH_ES_A256KW params) = algWithParamsObject params "ECDH-ES+A256KW"
- toJSON (A128GCMKW params) = algWithParamsObject params "A128GCMKW"
- toJSON (A192GCMKW params) = algWithParamsObject params "A192GCMKW"
- toJSON (A256GCMKW params) = algWithParamsObject params "A256GCMKW"
- toJSON (PBES2_HS256_A128KW params) = algWithParamsObject params "PBES2-HS256+A128KW"
- toJSON (PBES2_HS384_A192KW params) = algWithParamsObject params "PBES2-HS384+A192KW"
- toJSON (PBES2_HS512_A256KW params) = algWithParamsObject params "PBES2-HS512+A256KW"
+ toJSON (SimpleAlg a) = algObject $ case a of
+ RSA1_5 -> "RSA1_5"
+ RSA_OAEP -> "RSA-OAEP"
+ RSA_OAEP_256 -> "RSA-OAEP-256"
+ A128KW -> "A128KW"
+ A192KW -> "A192KW"
+ A256KW -> "A256KW"
+ Dir -> "dir"
+ toJSON (ECDHESAlg a params) = algWithParamsObject params $ case a of
+ ECDH_ES -> "ECDH-ES"
+ ECDH_ES_A128KW -> "ECDH-ES+A128KW"
+ ECDH_ES_A192KW -> "ECDH-ES+A192KW"
+ ECDH_ES_A256KW -> "ECDH-ES+A256KW"
+ toJSON (AESGCMAlg a params) = algWithParamsObject params $ case a of
+ A128GCMKW -> "A128GCMKW"
+ A192GCMKW -> "A192GCMKW"
+ A256GCMKW -> "A256GCMKW"
+ toJSON (PBES2Alg a params) = algWithParamsObject params $ case a of
+ PBES2_HS256_A128KW -> "PBES2-HS256+A128KW"
+ PBES2_HS384_A192KW -> "PBES2-HS384+A192KW"
+ PBES2_HS512_A256KW -> "PBES2-HS512+A256KW"
 
 
 -- | RFC 7518 §4.6.1. Header Parameters Used for ECDH Key Agreement
@@ -129,7 +186,7 @@ instance ToJSON ECDHParameters where
  toJSON (ECDHParameters epk apu apv) = object $ catMaybes
  [ Just ("epk" .= epk)
  , fmap ("apu" .=) apu
- , fmap ("apu" .=) apv
+ , fmap ("apv" .=) apv
  ]
 
 

src/Crypto/JOSE/JWA/JWK.hs

@@ -47,6 +47,7 @@ module Crypto.JOSE.JWA.JWK (
  , toRSAPublicKeyParameters
  , rsaE
  , rsaN
+ , rsaPrivateKey
  , rsaPrivateKeyParameters
  , rsaPublicKey
  , genRSA