chore: JWT warnings on failed JWT ops

Author: peppelinux

src/cryptojwt/jws/jws.py

@@ -227,13 +227,13 @@ def verify_compact_verbose(self, jws=None, keys=None, allow_none=False, sigalg=N
 
             try:
                 if not verifier.verify(jwt.sign_input(), jwt.signature(), _key):
-                    continue
-            except (BadSignature, IndexError):
-                pass
+-                   continue
+            except (BadSignature, IndexError) as err:
+                logger.warning(f'BadSignature caught with {jwt}: "{err}"')
             except (ValueError, TypeError) as err:
-                logger.warning('Exception "{}" caught'.format(err))
+                logger.warning(f'Exception with {jwt.headers}: "{err}"')
             else:
-                logger.debug("Verified message using key with kid=%s" % key.kid)
+                logger.debug(f"Verified message using key with kid={key.kid}")
                 self.msg = jwt.payload()
                 self.key = key
                 self._protected_headers = jwt.headers.copy()

src/cryptojwt/jwt.py

@@ -372,11 +372,11 @@ def unpack(self, token):
         if self.msg_cls:
             _msg_cls = self.msg_cls
         else:
-            try:
-                # try to find a issuer specific message class
-                _msg_cls = self.iss2msg_cls[_info["iss"]]
-            except KeyError:
-                _msg_cls = None
+            _msg_cls = self.iss2msg_cls.get(_info["iss"], None)
+            if not _msg_cls:
+                LOGGER.debug(
+                    f"both msg_cls and iss2msg are None for the issuer {_info['iss']}"
+                )
 
         if _msg_cls:
             vp_args = {"skew": self.skew}