fix(jwk): improve generate_private_key on binding class

Author: lepture

src/joserfc/_rfc7518/rsa_key.py

@@ -43,6 +43,14 @@ class RSABinding(CryptographyBinding):
 ssh_type=b"ssh-rsa"
 _cryptography_key_types= (RSAPrivateKey, RSAPublicKey)
 
+@staticmethod
+defgenerate_private_key(size: int) ->RSAPrivateKey:
+returngenerate_private_key(
+public_exponent=65537,
+key_size=size,
+backend=default_backend(),
+ )
+
 @staticmethod
 defimport_private_key(obj: RSADictKey) ->RSAPrivateKey:
 if"oth"inobj: # pragma: no cover
@@ -170,17 +178,13 @@ def generate_key(
 key_size=2048
 
 ifkey_size%8!=0:
-raiseValueError("Invalid key_size for RSAKey")
+raiseValueError("A bit size must be a multiple of 8")
 
 ifkey_size<2048:
 # https://csrc.nist.gov/publications/detail/sp/800-131a/rev-2/final
 warnings.warn("Key size should be >= 2048 bits", SecurityWarning)
 
-raw_key=generate_private_key(
-public_exponent=65537,
-key_size=key_size,
-backend=default_backend(),
- )
+raw_key=cls.binding.generate_private_key(key_size)
 ifprivate:
 key=cls(raw_key, raw_key, parameters)
 else:

src/joserfc/_rfc8037/okp_key.py

@@ -63,6 +63,8 @@ class OKPBinding(CryptographyBinding):
 
 @staticmethod
 defgenerate_private_key(crv: LiteralCurves) ->PrivateOKPKey:
+ifcrvnotinPRIVATE_KEYS_MAP:
+raiseInvalidKeyCurveError(f"Invalid curve value: '{crv}'")
 crv_key: t.Type[PrivateOKPKey] =PRIVATE_KEYS_MAP[crv]
 returncrv_key.generate()
 
@@ -190,12 +192,9 @@ def generate_key(
  :param auto_kid: add ``kid`` automatically
  """
 ifcrvisNone:
-crv="Ed25519"
-
-ifcrvnotinPRIVATE_KEYS_MAP:
-raiseInvalidKeyCurveError(f"Invalid curve value: '{crv}'")
-
-raw_key=cls.binding.generate_private_key(crv)
+raw_key=cls.binding.generate_private_key("Ed25519")
+else:
+raw_key=cls.binding.generate_private_key(crv)
 ifprivate:
 key=cls(raw_key, raw_key, parameters)
 else: