card_key_provider: remove method _verify_get_data from base class

The method _verify_get_data was intended to be used to verify the
user input before it further processed but ended up to be a simple
check that only checks the name of the key column very basically.

Unfortunately it is difficult to generalize the check code as the
concrete implementation of those checks is highly format dependent.
With the advent of eUICCs, we now have two data formats with
different lookup keys, so a static list with valid lookup keys is
also no longer up to the task.

After all it makes not much sense to keep this method, so let's
remove it.

(From the technical perspective, the key column is not limitied to
any specif field. In theory it would even be possible to use the KI
as lookup key as well, even though it would not make sense in
practice)

Related: SYS#7725
Change-Id: Ibf5745fb8a4f927397adff33900731524715d6a9

pySim/card_key_provider.py

@@ -132,26 +132,6 @@ class CardKeyFieldCryptor:
 class CardKeyProvider(abc.ABC):
     """Base class, not containing any concrete implementation."""
 
-    VALID_KEY_FIELD_NAMES = ['ICCID', 'EID', 'IMSI' ]
-
-    # check input parameters, but do nothing concrete yet
-    def _verify_get_data(self, fields: List[str] = [], key: str = 'ICCID', value: str = "") -> Dict[str, str]:
-        """Verify multiple fields for identified card.
-
-        Args:
-                fields : list of valid field names such as 'ADM1', 'PIN1', ... which are to be obtained
-                key : look-up key to identify card data, such as 'ICCID'
-                value : value for look-up key to identify card data
-        Returns:
-                dictionary of {field, value} strings for each requested field from 'fields'
-        """
-
-        if key not in self.VALID_KEY_FIELD_NAMES:
-            raise ValueError("Key field name '%s' is not a valid field name, valid field names are: %s" %
-                             (key, str(self.VALID_KEY_FIELD_NAMES)))
-
-        return {}
-
     def get_field(self, field: str, key: str = 'ICCID', value: str = "") -> Optional[str]:
         """get a single field from CSV file using a specified key/value pair"""
         fields = [field]
@@ -186,8 +166,6 @@ class CardKeyProviderCsv(CardKeyProvider):
         self.crypt = CardKeyFieldCryptor(transport_keys)
 
     def get(self, fields: List[str], key: str, value: str) -> Dict[str, str]:
-        super()._verify_get_data(fields, key, value)
-
         self.csv_file.seek(0)
         cr = csv.DictReader(self.csv_file)
         if not cr: