utils: Fix bugs in DataObject encoders

The DataObject is some weird / rarely used different code than the
normal TLV encoder/decoder.  It has apparently so far only been used
for decoding, without testing the encoding side, resulting in related
bugs.

Let's fix those that I encountered today, and add a test case.

Change-Id: I31370066f43c22fc3ce9e2b9ee75986a652f6fc4

pySim/utils.py

@@ -1333,7 +1333,7 @@ class DataObject(abc.ABC):
             bytes encoded in TLV format.
         """
         val = self.to_bytes()
-        return bytes(self._compute_tag()) + bytes(len(val)) + val
+        return bertlv_encode_tag(self._compute_tag()) + bertlv_encode_len(len(val)) + val
 
     # 'codec' interface
     def decode(self, binary: bytes) -> Tuple[dict, bytes]:
@@ -1481,7 +1481,8 @@ class DataObjectChoice(DataObjectCollection):
 
     # 'codec' interface
     def encode(self, decoded) -> bytes:
-        obj = self.members_by_name(decoded[0])
+        obj = self.members_by_name[list(decoded)[0]]
+        obj.decoded = list(decoded.values())[0]
         return obj.to_tlv()
 
 

tests/test_utils.py

@@ -4,6 +4,22 @@ import unittest
 from pySim import utils
 from pySim.ts_31_102 import EF_SUCI_Calc_Info
 
+# we don't really want to thest TS 102 221, but the underlying DataObject codebase
+from pySim.ts_102_221 import AM_DO_EF, AM_DO_DF, SC_DO
+
+class DoTestCase(unittest.TestCase):
+
+    def testSeqOfChoices(self):
+        """A sequence of two choices with each a variety of DO/TLVs"""
+        arr_seq = utils.DataObjectSequence('arr', sequence=[AM_DO_EF, SC_DO])
+        # input data
+        dec_in = [{'access_mode': ['update_erase', 'read_search_compare']}, {'control_reference_template':'PIN1'}]
+        # encode it once
+        encoded = arr_seq.encode(dec_in)
+        # decode again
+        re_decoded = arr_seq.decode(encoded)
+        self.assertEqual(dec_in, re_decoded[0])
+
 class DecTestCase(unittest.TestCase):
 	# TS33.501 Annex C.4 test keys
 	hnet_pubkey_profile_b = "0272DA71976234CE833A6907425867B82E074D44EF907DFB4B3E21C1C2256EBCD1" # ID 27 in test file