fix: allow jwt.encode to set default "typ" value

Author: lepture

src/joserfc/jwt.py

@@ -61,6 +61,7 @@ def encode(
     algorithms: list[str] | None = None,
     registry: JWSRegistry | JWERegistry | None = None,
     encoder_cls: Type[JSONEncoder] | None = None,
+    default_type: str | None = "JWT",
 ) -> str:
     """Encode a JSON Web Token with the given header, and claims.
 
@@ -70,9 +71,12 @@ def encode(
     :param algorithms: a list of allowed algorithms
     :param registry: a ``JWSRegistry`` or ``JWERegistry`` to use
     :param encoder_cls: A JSONEncoder subclass to use
+    :param default_type: default value of the ``typ`` header parameter
     """
-    # add ``typ`` in header
-    _header = {"typ": "JWT", **header}
+    if default_type is not None:
+        _header = {"typ": default_type, **header}
+    else:
+        _header = {**header}
     payload = convert_claims(claims, encoder_cls)
     if isinstance(registry, JWERegistry):
         return encrypt_compact(_header, payload, key, algorithms, registry)

tests/jwt/test_jwt.py

@@ -15,21 +15,34 @@ def use_embedded_jwk(obj: GuestProtocol) -> Key:
 
 
 class TestJWT(TestCase):
+    oct_key = OctKey.generate_key()
+
+    def test_default_type(self):
+        data = jwt.encode({"alg": "HS256"}, {"sub": "a"}, self.oct_key)
+        token = jwt.decode(data, self.oct_key)
+        self.assertEqual(token.header["typ"], "JWT")
+
+        data = jwt.encode({"alg": "HS256"}, {"sub": "a"}, self.oct_key, default_type=None)
+        token = jwt.decode(data, self.oct_key)
+        self.assertNotIn("typ", token.header)
+
+        data = jwt.encode({"alg": "HS256"}, {"sub": "a"}, self.oct_key, default_type="jwt+at")
+        token = jwt.decode(data, self.oct_key)
+        self.assertEqual(token.header["typ"], "jwt+at")
+
     def test_invalid_payload(self):
-        key = OctKey.import_key("secret")
-        data = jws.serialize_compact({"alg": "HS256"}, b"hello", key)
-        self.assertRaises(InvalidPayloadError, jwt.decode, data, key)
+        data = jws.serialize_compact({"alg": "HS256"}, b"hello", self.oct_key)
+        self.assertRaises(InvalidPayloadError, jwt.decode, data, self.oct_key)
 
     def test_claims_registry(self):
-        key = OctKey.import_key("secret")
-        data = jwt.encode({"alg": "HS256"}, {"sub": "a"}, key)
-        token = jwt.decode(data, key)
+        data = jwt.encode({"alg": "HS256"}, {"sub": "a"}, self.oct_key)
+        token = jwt.decode(data, self.oct_key)
 
         claims_registry = jwt.JWTClaimsRegistry(iss={"essential": True})
         self.assertRaises(MissingClaimError, claims_registry.validate, token.claims)
 
-        data = jwt.encode({"alg": "HS256"}, {"iss": "a"}, key)
-        obj = jwt.decode(data, key)
+        data = jwt.encode({"alg": "HS256"}, {"iss": "a"}, self.oct_key)
+        obj = jwt.decode(data, self.oct_key)
         self.assertEqual(obj.claims["iss"], "a")
 
     def test_jwe_format(self):