Network.OAuth

OAuth tools for using http-client for authenticated requests.

The functions here form the simplest basis for sending OAuthenticated Requests. In order to generate credentials according to the OAuth "three-legged workflow" use actions in the Network.OAuth.ThreeLegged module.

Authenticating a request

The oauthSimple function can be used to sign a Request as it stands. It should be performed just before the Request is used as it uses the current timestamp and thus may only be valid for a limited amount of time.

oauthSimple creates a new random entropy pool every time it is called, thus it can be both slow and cryptographically dangerous to use it repeatedly as it can drain system entropy. Instead, the plain oauth function should be used which allows for threading of the random source.

oauthSimple :: Cred ty -> Server -> Request -> IO Request

Sign a request with a fresh set of parameters. Uses MonadRandom IO, getting new entropy for each signing and thus is potentially dangerous if used too frequently. In almost all cases, oauth should be used instead with a suitably seeded PRNG.

oauth :: (MonadIO m, MonadRandom m) => Cred ty -> Server -> Request -> m Request

Sign a request with a fresh set of parameters.

Lower-level and pure functionality

When necessary to control or observe the signature more carefully, the lower level API can be used. This requires generating a fresh set of Oa parameters from a relevant or deterministic OaPin and then using sign to sign the Request.

sign :: Oa ty -> Server -> Request -> Request

Sign a request given generated parameters

Generating OAuth parameters

emptyOa :: Cred ty -> Oa ty

Uses emptyPin to create an empty set of params Oa.

freshOa :: (MonadRandom m, MonadIO m) => Cred ty -> m (Oa ty)

Uses freshPin to create a fresh, default set of params Oa.

emptyPin :: OaPin

An "empty" pin useful for testing. This OaPin is referentially transparent and thus has none of the necessary security features---it should never be used in an actual transaction!

freshPin :: (MonadRandom m, MonadIO m) => m OaPin

Creates a new, unique, unpredictable OaPin. This should be used quickly as dependent on the OAuth server settings it may expire.

OAuth Credentials

data Token ty

Tokens are public, private key pairs and come in many varieties, Client, Temporary, and Permanent.

Constructors

Token !Key !Secret

Instances

Eq (Token ty)

Defined in Network.OAuth.Types.Credentials

Methods

(==) :: Token ty -> Token ty -> Bool

(/=) :: Token ty -> Token ty -> Bool

Data ty => Data (Token ty)

Defined in Network.OAuth.Types.Credentials

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Token ty -> c (Token ty)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Token ty)

toConstr :: Token ty -> Constr

dataTypeOf :: Token ty -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Token ty))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Token ty))

gmapT :: (forall b. Data b => b -> b) -> Token ty -> Token ty

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Token ty -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Token ty -> r

gmapQ :: (forall d. Data d => d -> u) -> Token ty -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Token ty -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Token ty -> m (Token ty)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Token ty -> m (Token ty)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Token ty -> m (Token ty)

Ord (Token ty)

Defined in Network.OAuth.Types.Credentials

Methods

compare :: Token ty -> Token ty -> Ordering

(<) :: Token ty -> Token ty -> Bool

(<=) :: Token ty -> Token ty -> Bool

(>) :: Token ty -> Token ty -> Bool

(>=) :: Token ty -> Token ty -> Bool

max :: Token ty -> Token ty -> Token ty

min :: Token ty -> Token ty -> Token ty

Show (Token ty)

Defined in Network.OAuth.Types.Credentials

Methods

showsPrec :: Int -> Token ty -> ShowS

show :: Token ty -> String

showList :: [Token ty] -> ShowS

ToJSON (Token ty)

Produces a JSON object using keys named oauth_token and oauth_token_secret.

Defined in Network.OAuth.Types.Credentials

Methods

toJSON :: Token ty -> Value

toEncoding :: Token ty -> Encoding

toJSONList :: [Token ty] -> Value

toEncodingList :: [Token ty] -> Encoding

FromJSON (Token ty)

Parses a JSON object with keys oauth_token and oauth_token_secret, the standard format for OAuth 1.0.

Defined in Network.OAuth.Types.Credentials

Methods

parseJSON :: Value -> Parser (Token ty)

parseJSONList :: Value -> Parser [Token ty]

data Cred ty

Credentials pair a Client Token and either a Temporary or Permanent token corresponding to a particular set of user resources on the server.

Instances

Eq (Cred ty)

Defined in Network.OAuth.Types.Credentials

Methods

(==) :: Cred ty -> Cred ty -> Bool

(/=) :: Cred ty -> Cred ty -> Bool

Data ty => Data (Cred ty)

Defined in Network.OAuth.Types.Credentials

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Cred ty -> c (Cred ty)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Cred ty)

toConstr :: Cred ty -> Constr

dataTypeOf :: Cred ty -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Cred ty))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Cred ty))

gmapT :: (forall b. Data b => b -> b) -> Cred ty -> Cred ty

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Cred ty -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Cred ty -> r

gmapQ :: (forall d. Data d => d -> u) -> Cred ty -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Cred ty -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Cred ty -> m (Cred ty)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Cred ty -> m (Cred ty)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Cred ty -> m (Cred ty)

Ord (Cred ty)

Defined in Network.OAuth.Types.Credentials

Methods

compare :: Cred ty -> Cred ty -> Ordering

(<) :: Cred ty -> Cred ty -> Bool

(<=) :: Cred ty -> Cred ty -> Bool

(>) :: Cred ty -> Cred ty -> Bool

(>=) :: Cred ty -> Cred ty -> Bool

max :: Cred ty -> Cred ty -> Cred ty

min :: Cred ty -> Cred ty -> Cred ty

Show (Cred ty)

Defined in Network.OAuth.Types.Credentials

Methods

showsPrec :: Int -> Cred ty -> ShowS

show :: Cred ty -> String

showList :: [Cred ty] -> ShowS

data Client

Client Credentials and Tokens are assigned to a particular client by the server and are used for all requests sent by that client. They form the core component of resource specific credentials.

Instances

Data Client

Defined in Network.OAuth.Types.Credentials

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Client -> c Client

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Client

toConstr :: Client -> Constr

dataTypeOf :: Client -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Client)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Client)

gmapT :: (forall b. Data b => b -> b) -> Client -> Client

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Client -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Client -> r

gmapQ :: (forall d. Data d => d -> u) -> Client -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Client -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Client -> m Client

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Client -> m Client

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Client -> m Client

data Temporary

Temporary Tokens and Credentials are created during authorization protocols and are rarely meant to be kept for more than a few minutes. Typically they are authorized to access only a very select set of server resources. During "three-legged authorization" in OAuth 1.0 they are used to generate the authorization request URI the client sends and, after that, in the Permanent Token request.

Instances

Data Temporary

Defined in Network.OAuth.Types.Credentials

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Temporary -> c Temporary

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Temporary

toConstr :: Temporary -> Constr

dataTypeOf :: Temporary -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Temporary)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Temporary)

gmapT :: (forall b. Data b => b -> b) -> Temporary -> Temporary

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Temporary -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Temporary -> r

gmapQ :: (forall d. Data d => d -> u) -> Temporary -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Temporary -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Temporary -> m Temporary

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Temporary -> m Temporary

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Temporary -> m Temporary

ResourceToken Temporary

Defined in Network.OAuth.Types.Credentials

Methods

upgradeCred' :: Token Temporary -> Cred tk' -> Cred Temporary

data Permanent

Permanent Tokens and Credentials are the primary means of accessing server resources. They must be maintained by the client for each user who authorizes that client to access resources on their behalf.

Instances

Data Permanent

Defined in Network.OAuth.Types.Credentials

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Permanent -> c Permanent

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Permanent

toConstr :: Permanent -> Constr

dataTypeOf :: Permanent -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Permanent)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Permanent)

gmapT :: (forall b. Data b => b -> b) -> Permanent -> Permanent

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Permanent -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Permanent -> r

gmapQ :: (forall d. Data d => d -> u) -> Permanent -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Permanent -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Permanent -> m Permanent

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Permanent -> m Permanent

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Permanent -> m Permanent

ResourceToken Permanent

Defined in Network.OAuth.Types.Credentials

Methods

upgradeCred' :: Token Permanent -> Cred tk' -> Cred Permanent

Creating Credentials

clientCred :: Token Client -> Cred Client

temporaryCred :: Token Temporary -> Cred Client -> Cred Temporary

permanentCred :: Token Permanent -> Cred Client -> Cred Permanent

fromUrlEncoded :: ByteString -> Maybe (Bool, Token ty)

Parses a www-form-urlencoded stream to produce a Token if possible. The first result value is whether or not the token data is OAuth 1.0a compatible.

>>> fromUrlEncoded "oauth_token=key&oauth_token_secret=secret"
Just (False, Token "key" "secret")

>>> fromUrlEncoded "oauth_token=key&oauth_token_secret=secret&oauth_callback_confirmed=true"
Just (True, Token "key" "secret")

OAuth Configuration

data Server

The Server information contains details which parameterize how a particular server wants to interpret OAuth requests.

Constructors

Server

Fields

• parameterMethod :: ParameterMethod
• signatureMethod :: SignatureMethod
• oAuthVersion :: Version

Instances

Eq Server

Defined in Network.OAuth.Types.Params

Methods

(==) :: Server -> Server -> Bool

(/=) :: Server -> Server -> Bool

Data Server

Defined in Network.OAuth.Types.Params

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Server -> c Server

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Server

toConstr :: Server -> Constr

dataTypeOf :: Server -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Server)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Server)

gmapT :: (forall b. Data b => b -> b) -> Server -> Server

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Server -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Server -> r

gmapQ :: (forall d. Data d => d -> u) -> Server -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Server -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Server -> m Server

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Server -> m Server

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Server -> m Server

Ord Server

Defined in Network.OAuth.Types.Params

Methods

compare :: Server -> Server -> Ordering

(<) :: Server -> Server -> Bool

(<=) :: Server -> Server -> Bool

(>) :: Server -> Server -> Bool

(>=) :: Server -> Server -> Bool

max :: Server -> Server -> Server

min :: Server -> Server -> Server

Show Server

Defined in Network.OAuth.Types.Params

Methods

showsPrec :: Int -> Server -> ShowS

show :: Server -> String

showList :: [Server] -> ShowS

defaultServer :: Server

The default Server parameterization uses OAuth recommended parameters.

data ParameterMethod

The OAuth spec suggest that the OAuth parameter be passed via the Authorization header, but allows for other methods of transmission (see section "3.5. Parameter Transmission") so we select the Server's preferred method with this type.

Constructors

AuthorizationHeader

Place the Oa parameters in the Authorization HTTP header.

RequestEntityBody

Augment the www-form-urlencoded request body with Oa parameters.

QueryString

Augment the www-form-urlencoded query string with Oa parameters.

Instances

Eq ParameterMethod

Defined in Network.OAuth.Types.Params

Methods

(==) :: ParameterMethod -> ParameterMethod -> Bool

(/=) :: ParameterMethod -> ParameterMethod -> Bool

Data ParameterMethod

Defined in Network.OAuth.Types.Params

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ParameterMethod -> c ParameterMethod

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ParameterMethod

toConstr :: ParameterMethod -> Constr

dataTypeOf :: ParameterMethod -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ParameterMethod)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ParameterMethod)

gmapT :: (forall b. Data b => b -> b) -> ParameterMethod -> ParameterMethod

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ParameterMethod -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ParameterMethod -> r

gmapQ :: (forall d. Data d => d -> u) -> ParameterMethod -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> ParameterMethod -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ParameterMethod -> m ParameterMethod

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ParameterMethod -> m ParameterMethod

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ParameterMethod -> m ParameterMethod

Ord ParameterMethod

Defined in Network.OAuth.Types.Params

Methods

compare :: ParameterMethod -> ParameterMethod -> Ordering

(<) :: ParameterMethod -> ParameterMethod -> Bool

(<=) :: ParameterMethod -> ParameterMethod -> Bool

(>) :: ParameterMethod -> ParameterMethod -> Bool

(>=) :: ParameterMethod -> ParameterMethod -> Bool

max :: ParameterMethod -> ParameterMethod -> ParameterMethod

min :: ParameterMethod -> ParameterMethod -> ParameterMethod

Show ParameterMethod

Defined in Network.OAuth.Types.Params

Methods

showsPrec :: Int -> ParameterMethod -> ShowS

show :: ParameterMethod -> String

showList :: [ParameterMethod] -> ShowS

data SignatureMethod

OAuth culminates in the creation of the oauth_signature which signs and authenticates the request using the secret components of a particular OAuth Cred.

Several methods exist for generating these signatures, the most popular being HmacSha1.

Constructors

HmacSha1

Plaintext

Instances

Eq SignatureMethod

Defined in Network.OAuth.Types.Params

Methods

(==) :: SignatureMethod -> SignatureMethod -> Bool

(/=) :: SignatureMethod -> SignatureMethod -> Bool

Data SignatureMethod

Defined in Network.OAuth.Types.Params

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> SignatureMethod -> c SignatureMethod

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c SignatureMethod

toConstr :: SignatureMethod -> Constr

dataTypeOf :: SignatureMethod -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c SignatureMethod)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c SignatureMethod)

gmapT :: (forall b. Data b => b -> b) -> SignatureMethod -> SignatureMethod

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> SignatureMethod -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> SignatureMethod -> r

gmapQ :: (forall d. Data d => d -> u) -> SignatureMethod -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> SignatureMethod -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> SignatureMethod -> m SignatureMethod

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> SignatureMethod -> m SignatureMethod

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> SignatureMethod -> m SignatureMethod

Ord SignatureMethod

Defined in Network.OAuth.Types.Params

Methods

compare :: SignatureMethod -> SignatureMethod -> Ordering

(<) :: SignatureMethod -> SignatureMethod -> Bool

(<=) :: SignatureMethod -> SignatureMethod -> Bool

(>) :: SignatureMethod -> SignatureMethod -> Bool

(>=) :: SignatureMethod -> SignatureMethod -> Bool

max :: SignatureMethod -> SignatureMethod -> SignatureMethod

min :: SignatureMethod -> SignatureMethod -> SignatureMethod

Show SignatureMethod

Defined in Network.OAuth.Types.Params

Methods

showsPrec :: Int -> SignatureMethod -> ShowS

show :: SignatureMethod -> String

showList :: [SignatureMethod] -> ShowS

QueryValueLike SignatureMethod

Defined in Network.OAuth.Types.Params

Methods

toQueryValue :: SignatureMethod -> Maybe ByteString

data Version

OAuth has progressed through several versions since its inception. In particular, there are two community editions "OAuth Core 1.0" (2007) and "OAuth Core 1.0a" (2009) along with the IETF Official version RFC 5849 (2010) which is confusingly named "OAuth 1.0".

/Servers which only implement the obsoleted community edition "OAuth Core 1.0" are susceptible to a session fixation attack./

If at all possible, choose the RFC 5849 version (the OAuth1 value) as it is the modern standard. Some servers may only be compliant with an earlier OAuth version---this should be tested against each server, in particular the protocols defined in Network.OAuth.ThreeLegged.

Constructors

OAuthCommunity1

OAuth Core 1.0 Community Edition

OAuthCommunity1a

OAuth Core 1.0 Community Edition, Revision A

OAuth1

RFC 5849

Instances

Eq Version

Defined in Network.OAuth.Types.Params

Methods

(==) :: Version -> Version -> Bool

(/=) :: Version -> Version -> Bool

Data Version

Defined in Network.OAuth.Types.Params

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Version -> c Version

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Version

toConstr :: Version -> Constr

dataTypeOf :: Version -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Version)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Version)

gmapT :: (forall b. Data b => b -> b) -> Version -> Version

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Version -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Version -> r

gmapQ :: (forall d. Data d => d -> u) -> Version -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Version -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Version -> m Version

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Version -> m Version

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Version -> m Version

Ord Version

Defined in Network.OAuth.Types.Params

Methods

compare :: Version -> Version -> Ordering

(<) :: Version -> Version -> Bool

(<=) :: Version -> Version -> Bool

(>) :: Version -> Version -> Bool

(>=) :: Version -> Version -> Bool

max :: Version -> Version -> Version

min :: Version -> Version -> Version

Show Version

Defined in Network.OAuth.Types.Params

Methods

showsPrec :: Int -> Version -> ShowS

show :: Version -> String

showList :: [Version] -> ShowS

QueryValueLike Version

All three OAuth 1.0 versions confusingly report the same version number.

Defined in Network.OAuth.Types.Params

Methods

toQueryValue :: Version -> Maybe ByteString