workaround for CAPDU's inability to handle le=0000

virtualsmartcard/src/vpicc/virtualsmartcard/SEutils.py

@@ -18,7 +18,7 @@
 #
 from virtualsmartcard.TLVutils import pack, unpack, bertlv_pack
 from virtualsmartcard.ConstantDefinitions import CRT_TEMPLATE, ALGO_MAPPING, \
-    SM_Class
+    SM_Class, MAX_EXTENDED_LE
 from virtualsmartcard.utils import inttostring, stringtoint, C_APDU
 from virtualsmartcard.SWutils import SwError, SW
 import virtualsmartcard.CryptoUtils as vsCrypto
@@ -398,7 +398,10 @@ class Security_Environment(object):
 
         if isinstance(le, str):
             # FIXME C_APDU only handles le with strings of length 1. Better patch utils.py to support extended length apdus
-            le = stringtoint(le)
+            le_int = stringtoint(le)
+            if le_int == 0 and len(le) > 1:
+                le_int = MAX_EXTENDED_LE
+            le = le_int
         
         c = C_APDU(cla=cla, ins=ins, p1=p1, p2=p2, le=le, data="".join(return_data))
         return c