Crypto.JWT

JSON Web Token implementation (RFC 7519). A JWT is a JWS with a payload of claims to be transferred between two parties.

JWTs use the JWS compact serialisation. See Crypto.JOSE.Compact for details.

mkClaims :: IO ClaimsSet
mkClaims = do
  t <- currentTime
  pure $ emptyClaimsSet
    & claimIss ?~ "alice"
    & claimAud ?~ Audience ["bob"]
    & claimIat ?~ NumericDate t

doJwtSign :: JWK -> ClaimsSet -> IO (Either JWTError SignedJWT)
doJwtSign jwk claims = runExceptT $ do
  alg <- bestJWSAlg jwk
  signClaims jwk (newJWSHeader ((), alg)) claims

doJwtVerify :: JWK -> SignedJWT -> IO (Either JWTError ClaimsSet)
doJwtVerify jwk jwt = runExceptT $ do
  let config = defaultJWTValidationSettings (== "bob")
  verifyClaims config jwk jwt

Some JWT libraries have a function that takes two strings: the "secret" (a symmetric key) and the raw JWT. The following function achieves the same:

verify :: L.ByteString -> L.ByteString -> IO (Either JWTError ClaimsSet)
verify k s = runExceptT $ do
  let
    k' = fromOctets k      -- turn raw secret into symmetric JWK
    audCheck = const True  -- should be a proper audience check
  s' <- decodeCompact s    -- decode JWT
  verifyClaims (defaultJWTValidationSettings audCheck) k' s'

Creating a JWT

signClaims :: (MonadRandom m, MonadError e m, AsError e) => JWK -> JWSHeader () -> ClaimsSet -> m SignedJWT

Create a JWS JWT

type SignedJWT = CompactJWS JWSHeader

A digitally signed or MACed JWT

Validating a JWT and extracting claims

defaultJWTValidationSettings :: (StringOrURI -> Bool) -> JWTValidationSettings

Acquire the default validation settings.

RFC 7519 §4.1.3. states that applications MUST identify itself with a value in the audience claim, therefore a predicate must be supplied.

The other defaults are:

• defaultValidationSettings for JWS verification
• Zero clock skew tolerance when validating nbf, exp and iat claims
• iat claim is checked
• issuer claim is not checked

verifyClaims :: (MonadTime m, HasAllowedSkew a, HasAudiencePredicate a, HasIssuerPredicate a, HasCheckIssuedAt a, HasValidationSettings a, AsError e, AsJWTError e, MonadError e m, VerificationKeyStore m (JWSHeader ()) ClaimsSet k) => a -> k -> SignedJWT -> m ClaimsSet

Cryptographically verify a JWS JWT, then validate the Claims Set, returning it if valid.

This is the only way to get at the claims of a JWS JWT, enforcing that the claims are cryptographically and semantically valid before the application can use them.

See also verifyClaimsAt which allows you to explicitly specify the time.

verifyClaimsAt :: (HasAllowedSkew a, HasAudiencePredicate a, HasIssuerPredicate a, HasCheckIssuedAt a, HasValidationSettings a, AsError e, AsJWTError e, MonadError e m, VerificationKeyStore (ReaderT WrappedUTCTime m) (JWSHeader ()) ClaimsSet k) => a -> k -> UTCTime -> SignedJWT -> m ClaimsSet

Cryptographically verify a JWS JWT, then validate the Claims Set, returning it if valid.

This is the same as verifyClaims except that the time is explicitly provided. If you process many requests per second this will allow you to avoid unnecessary repeat system calls.

class HasAllowedSkew s where

Maximum allowed skew when validating the nbf, exp and iat claims.

Methods

allowedSkew :: Lens' s NominalDiffTime

Instances

HasJWTValidationSettings a => HasAllowedSkew a

Defined in Crypto.JWT

Methods

allowedSkew :: Lens' a NominalDiffTime

class HasAudiencePredicate s where

Predicate for checking values in the aud claim.

Methods

audiencePredicate :: Lens' s (StringOrURI -> Bool)

Instances

HasJWTValidationSettings a => HasAudiencePredicate a

Defined in Crypto.JWT

Methods

audiencePredicate :: Lens' a (StringOrURI -> Bool)

class HasIssuerPredicate s where

Predicate for checking the iss claim.

Methods

issuerPredicate :: Lens' s (StringOrURI -> Bool)

Instances

HasJWTValidationSettings a => HasIssuerPredicate a

Defined in Crypto.JWT

Methods

issuerPredicate :: Lens' a (StringOrURI -> Bool)

class HasCheckIssuedAt s where

Whether to check that the iat claim is not in the future.

Methods

checkIssuedAt :: Lens' s Bool

Instances

HasJWTValidationSettings a => HasCheckIssuedAt a

Defined in Crypto.JWT

Methods

checkIssuedAt :: Lens' a Bool

data JWTValidationSettings

Instances

HasJWTValidationSettings JWTValidationSettings

Defined in Crypto.JWT

Methods

jWTValidationSettings :: Lens' JWTValidationSettings JWTValidationSettings

jwtValidationSettingsAllowedSkew :: Lens' JWTValidationSettings NominalDiffTime

jwtValidationSettingsAudiencePredicate :: Lens' JWTValidationSettings (StringOrURI -> Bool)

jwtValidationSettingsCheckIssuedAt :: Lens' JWTValidationSettings Bool

jwtValidationSettingsIssuerPredicate :: Lens' JWTValidationSettings (StringOrURI -> Bool)

jwtValidationSettingsValidationSettings :: Lens' JWTValidationSettings ValidationSettings

class HasJWTValidationSettings c where

Minimal complete definition

jWTValidationSettings

Methods

jWTValidationSettings :: Lens' c JWTValidationSettings

jwtValidationSettingsAllowedSkew :: Lens' c NominalDiffTime

jwtValidationSettingsAudiencePredicate :: Lens' c (StringOrURI -> Bool)

jwtValidationSettingsCheckIssuedAt :: Lens' c Bool

jwtValidationSettingsIssuerPredicate :: Lens' c (StringOrURI -> Bool)

jwtValidationSettingsValidationSettings :: Lens' c ValidationSettings

Instances

HasJWTValidationSettings JWTValidationSettings

Defined in Crypto.JWT

Methods

jWTValidationSettings :: Lens' JWTValidationSettings JWTValidationSettings

jwtValidationSettingsAllowedSkew :: Lens' JWTValidationSettings NominalDiffTime

jwtValidationSettingsAudiencePredicate :: Lens' JWTValidationSettings (StringOrURI -> Bool)

jwtValidationSettingsCheckIssuedAt :: Lens' JWTValidationSettings Bool

jwtValidationSettingsIssuerPredicate :: Lens' JWTValidationSettings (StringOrURI -> Bool)

jwtValidationSettingsValidationSettings :: Lens' JWTValidationSettings ValidationSettings

Claims Set

data ClaimsSet

The JWT Claims Set represents a JSON object whose members are the registered claims defined by RFC 7519. Unrecognised claims are gathered into the unregisteredClaims map.

Instances

Eq ClaimsSet

Defined in Crypto.JWT

Methods

(==) :: ClaimsSet -> ClaimsSet -> Bool

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

Show ClaimsSet

Defined in Crypto.JWT

Methods

showsPrec :: Int -> ClaimsSet -> ShowS

show :: ClaimsSet -> String

showList :: [ClaimsSet] -> ShowS

ToJSON ClaimsSet

Defined in Crypto.JWT

Methods

toJSON :: ClaimsSet -> Value

toEncoding :: ClaimsSet -> Encoding

toJSONList :: [ClaimsSet] -> Value

toEncodingList :: [ClaimsSet] -> Encoding

FromJSON ClaimsSet

Defined in Crypto.JWT

Methods

parseJSON :: Value -> Parser ClaimsSet

parseJSONList :: Value -> Parser [ClaimsSet]

claimAud :: Lens' ClaimsSet (Maybe Audience)

The audience claim identifies the recipients that the JWT is intended for. Each principal intended to process the JWT MUST identify itself with a value in the audience claim. If the principal processing the claim does not identify itself with a value in the aud claim when this claim is present, then the JWT MUST be rejected.

claimExp :: Lens' ClaimsSet (Maybe NumericDate)

The expiration time claim identifies the expiration time on or after which the JWT MUST NOT be accepted for processing. The processing of exp claim requires that the current date/time MUST be before expiration date/time listed in the exp claim. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew.

claimIat :: Lens' ClaimsSet (Maybe NumericDate)

The issued at claim identifies the time at which the JWT was issued. This claim can be used to determine the age of the JWT.

claimIss :: Lens' ClaimsSet (Maybe StringOrURI)

The issuer claim identifies the principal that issued the JWT. The processing of this claim is generally application specific.

claimJti :: Lens' ClaimsSet (Maybe Text)

The JWT ID claim provides a unique identifier for the JWT. The identifier value MUST be assigned in a manner that ensures that there is a negligible probability that the same value will be accidentally assigned to a different data object. The jti claim can be used to prevent the JWT from being replayed. The jti value is a case-sensitive string.

claimNbf :: Lens' ClaimsSet (Maybe NumericDate)

The not before claim identifies the time before which the JWT MUST NOT be accepted for processing. The processing of the nbf claim requires that the current date/time MUST be after or equal to the not-before date/time listed in the nbf claim. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew.

claimSub :: Lens' ClaimsSet (Maybe StringOrURI)

The subject claim identifies the principal that is the subject of the JWT. The Claims in a JWT are normally statements about the subject. The subject value MAY be scoped to be locally unique in the context of the issuer or MAY be globally unique. The processing of this claim is generally application specific.

unregisteredClaims :: Lens' ClaimsSet (HashMap Text Value)

Claim Names can be defined at will by those using JWTs.

addClaim :: Text -> Value -> ClaimsSet -> ClaimsSet

emptyClaimsSet :: ClaimsSet

Return an empty claims set.

validateClaimsSet :: (MonadTime m, HasAllowedSkew a, HasAudiencePredicate a, HasIssuerPredicate a, HasCheckIssuedAt a, AsJWTError e, MonadError e m) => a -> ClaimsSet -> m ClaimsSet

Validate the claims made by a ClaimsSet.

These checks are performed by verifyClaims, which also validates any signatures, so you shouldn't need to use this function directly.

JWT errors

data JWTError

Constructors

JWSError Error

A JOSE error occurred while processing the JWT

JWTClaimsSetDecodeError String

The JWT payload is not a JWT Claims Set

JWTExpired

JWTNotYetValid

JWTNotInIssuer

JWTNotInAudience

JWTIssuedAtFuture

Instances

Eq JWTError

Defined in Crypto.JWT

Methods

(==) :: JWTError -> JWTError -> Bool

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

Show JWTError

Defined in Crypto.JWT

Methods

showsPrec :: Int -> JWTError -> ShowS

show :: JWTError -> String

showList :: [JWTError] -> ShowS

AsError JWTError

Defined in Crypto.JWT

Methods

_Error :: Prism' JWTError Error

_AlgorithmNotImplemented :: Prism' JWTError ()

_AlgorithmMismatch :: Prism' JWTError String

_KeyMismatch :: Prism' JWTError Text

_KeySizeTooSmall :: Prism' JWTError ()

_OtherPrimesNotSupported :: Prism' JWTError ()

_RSAError :: Prism' JWTError Error

_CryptoError :: Prism' JWTError CryptoError

_CompactDecodeError :: Prism' JWTError CompactDecodeError

_JSONDecodeError :: Prism' JWTError String

_NoUsableKeys :: Prism' JWTError ()

_JWSCritUnprotected :: Prism' JWTError ()

_JWSNoValidSignatures :: Prism' JWTError ()

_JWSInvalidSignature :: Prism' JWTError ()

_JWSNoSignatures :: Prism' JWTError ()

AsJWTError JWTError

Defined in Crypto.JWT

Methods

_JWTError :: Prism' JWTError JWTError

_JWSError :: Prism' JWTError Error

_JWTClaimsSetDecodeError :: Prism' JWTError String

_JWTExpired :: Prism' JWTError ()

_JWTNotYetValid :: Prism' JWTError ()

_JWTNotInIssuer :: Prism' JWTError ()

_JWTNotInAudience :: Prism' JWTError ()

_JWTIssuedAtFuture :: Prism' JWTError ()

class AsJWTError r where

Minimal complete definition

_JWTError

Methods

_JWTError :: Prism' r JWTError

_JWSError :: Prism' r Error

_JWTClaimsSetDecodeError :: Prism' r String

_JWTExpired :: Prism' r ()

_JWTNotYetValid :: Prism' r ()

_JWTNotInIssuer :: Prism' r ()

_JWTNotInAudience :: Prism' r ()

_JWTIssuedAtFuture :: Prism' r ()

Instances

AsJWTError JWTError

Defined in Crypto.JWT

Methods

_JWTError :: Prism' JWTError JWTError

_JWSError :: Prism' JWTError Error

_JWTClaimsSetDecodeError :: Prism' JWTError String

_JWTExpired :: Prism' JWTError ()

_JWTNotYetValid :: Prism' JWTError ()

_JWTNotInIssuer :: Prism' JWTError ()

_JWTNotInAudience :: Prism' JWTError ()

_JWTIssuedAtFuture :: Prism' JWTError ()

Miscellaneous

newtype Audience

Audience data. In the general case, the aud value is an array of case-sensitive strings, each containing a StringOrURI value. In the special case when the JWT has one audience, the aud value MAY be a single case-sensitive string containing a StringOrURI value.

The ToJSON instance formats an Audience with one value as a string (some non-compliant implementations require this.)

Constructors

Audience [StringOrURI]

Instances

Eq Audience

Defined in Crypto.JWT

Methods

(==) :: Audience -> Audience -> Bool

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

Show Audience

Defined in Crypto.JWT

Methods

showsPrec :: Int -> Audience -> ShowS

show :: Audience -> String

showList :: [Audience] -> ShowS

ToJSON Audience

Defined in Crypto.JWT

Methods

toJSON :: Audience -> Value

toEncoding :: Audience -> Encoding

toJSONList :: [Audience] -> Value

toEncodingList :: [Audience] -> Encoding

FromJSON Audience

Defined in Crypto.JWT

Methods

parseJSON :: Value -> Parser Audience

parseJSONList :: Value -> Parser [Audience]

data StringOrURI

A JSON string value, with the additional requirement that while arbitrary string values MAY be used, any value containing a : character MUST be a URI.

Note: the IsString instance will fail if the string contains a : but does not parse as a URI. Use stringOrUri directly in this situation.

Instances

Eq StringOrURI

Defined in Crypto.JWT

Methods

(==) :: StringOrURI -> StringOrURI -> Bool

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

Show StringOrURI

Defined in Crypto.JWT

Methods

showsPrec :: Int -> StringOrURI -> ShowS

show :: StringOrURI -> String

showList :: [StringOrURI] -> ShowS

IsString StringOrURI

Non-total. A string with a : in it MUST parse as a URI

Defined in Crypto.JWT

Methods

fromString :: String -> StringOrURI

ToJSON StringOrURI

Defined in Crypto.JWT

Methods

toJSON :: StringOrURI -> Value

toEncoding :: StringOrURI -> Encoding

toJSONList :: [StringOrURI] -> Value

toEncodingList :: [StringOrURI] -> Encoding

FromJSON StringOrURI

Defined in Crypto.JWT

Methods

parseJSON :: Value -> Parser StringOrURI

parseJSONList :: Value -> Parser [StringOrURI]

stringOrUri :: (Cons s s Char Char, AsEmpty s) => Prism' s StringOrURI

string :: Prism' StringOrURI Text

uri :: Prism' StringOrURI URI

newtype NumericDate

A JSON numeric value representing the number of seconds from 1970-01-01T0:0:0Z UTC until the specified UTC date/time.

Constructors

NumericDate UTCTime

Instances

Eq NumericDate

Defined in Crypto.JWT

Methods

(==) :: NumericDate -> NumericDate -> Bool

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

Ord NumericDate

Defined in Crypto.JWT

Methods

compare :: NumericDate -> NumericDate -> Ordering

(<) :: NumericDate -> NumericDate -> Bool

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

(>) :: NumericDate -> NumericDate -> Bool

(>=) :: NumericDate -> NumericDate -> Bool

max :: NumericDate -> NumericDate -> NumericDate

min :: NumericDate -> NumericDate -> NumericDate

Show NumericDate

Defined in Crypto.JWT

Methods

showsPrec :: Int -> NumericDate -> ShowS

show :: NumericDate -> String

showList :: [NumericDate] -> ShowS

ToJSON NumericDate

Defined in Crypto.JWT

Methods

toJSON :: NumericDate -> Value

toEncoding :: NumericDate -> Encoding

toJSONList :: [NumericDate] -> Value

toEncodingList :: [NumericDate] -> Encoding

FromJSON NumericDate

Defined in Crypto.JWT

Methods

parseJSON :: Value -> Parser NumericDate

parseJSONList :: Value -> Parser [NumericDate]

module Crypto.JOSE

Orphan instances

HasJWTValidationSettings a => HasValidationSettings a

Methods

validationSettings :: Lens' a ValidationSettings

validationSettingsAlgorithms :: Lens' a (Set Alg)

validationSettingsValidationPolicy :: Lens' a ValidationPolicy