Use the blocklength of the actual cipher to append padding (instead of hardcoded

DES-CBC blocklength)


git-svn-id: https://vsmartcard.svn.sourceforge.net/svnroot/vsmartcard@682 96b47cad-a561-4643-ad3b-153ac7d7599c

virtualsmartcard/src/vpicc/virtualsmartcard/CryptoUtils.py

@@ -89,13 +89,12 @@ def get_cipher_blocklen(cipherspec):
     cipher = globals().get(cipherparts[0].upper(), None)
     return cipher.block_size
 
-def append_padding(cipherspec, data, padding_class=0x01):
+def append_padding(blocklen, data, padding_class=0x01):
     """Append padding to the data. 
     Length of padding depends on length of data and the block size of the
     specified encryption algorithm.
     Different types of padding may be selected via the padding_class parameter
     """
-    blocklen = get_cipher_blocklen(cipherspec)
 
     if padding_class == 0x01: #ISO padding
         last_block_length = len(data) % blocklen

virtualsmartcard/src/vpicc/virtualsmartcard/SEutils.py

@@ -56,6 +56,7 @@ class ControlReferenceTemplate:
         self.DFref = None
         self.keylength = None
         self.algorithm = None
+        self.blocklength = None
         self.usage_qualifier = None
         if config != "":
             self.parse_SE_config(config)
@@ -283,7 +284,7 @@ class Security_Environment(object):
         if authenticate_header:
             to_authenticate = inttostring(CAPDU.cla) + inttostring(CAPDU.ins)+\
                               inttostring(CAPDU.p1) + inttostring(CAPDU.p2)
-            to_authenticate = vsCrypto.append_padding("DES-CBC", to_authenticate)
+            to_authenticate = vsCrypto.append_padding(self.cct.blocklength, to_authenticate)
         else:
             to_authenticate = ""
 
@@ -366,7 +367,7 @@ class Security_Environment(object):
 
             #SM data objects for authentication 
             if tag == SM_Class["CHECKSUM"]:
-                auth = vsCrypto.append_padding("DES-CBC", to_authenticate)
+                auth = vsCrypto.append_padding(self.cct.algorithm, to_authenticate)
                 sw, checksum = self.compute_cryptographic_checksum(0x8E,
                                                                    0x80,
                                                                    auth)
@@ -437,9 +438,9 @@ class Security_Environment(object):
         if sw == SW["NORMAL"]:
             if self.cct.algorithm == None:
                 raise SwError(SW["CONDITIONSNOTSATISFIED"])
-            elif self.cct.algorithm == "CCT":
+            elif self.cct.algorithm == "CC":
                 tag = SM_Class["CHECKSUM"]
-                padded = vsCrypto.append_padding("DES-ECB", return_data)
+                padded = vsCrypto.append_padding(self.cct.blocklength, return_data)
                 sw, auth = self.compute_cryptographic_checksum(0x8E, 0x80, padded)
                 length = len(auth)
                 return_data += pack([(tag, length, auth)])
@@ -638,7 +639,7 @@ class Security_Environment(object):
         if key == None or algo == None:
             return SW["ERR_CONDITIONNOTSATISFIED"], ""
         else:
-            padded = vsCrypto.append_padding(algo, data)
+            padded = vsCrypto.append_padding(vsCrypto.get_cipher_blocklen(algo), data)
             crypted = vsCrypto.encrypt(algo, key, padded, self.ct.iv)
             return SW["NORMAL"], crypted
 

virtualsmartcard/src/vpicc/virtualsmartcard/cards/ePass.py

@@ -33,6 +33,7 @@ class ePass_SE(Security_Environment):
         Security_Environment.__init__(self, MF, SAM)
         self.ssc = ssc
         self.cct.algorithm = "CC"
+        self.cct.blocklength = 8
         self.ct.algorithm = "DES3-CBC"
            
     def compute_cryptographic_checksum(self, p1, p2, data):

virtualsmartcard/src/vpicc/virtualsmartcard/cards/nPA.py

@@ -67,6 +67,8 @@ class nPA_SE(Security_Environment):
     def __init__(self, MF, SAM):
         Security_Environment.__init__(self, MF, SAM)
         self.at = nPA_AT_CRT() 
+        #This breaks support for 3DES
+        self.cct.blocklength = 16
         self.eac_step = 0
         self.sec = None
         self.eac_ctx = None