some mtcos tlv decoding

git-svn-id: svn+ssh://localhost/home/henryk/svn/cyberflex-shell/trunk@94 f711b948-2313-0410-aaa9-d29f33439f0b

1 files changed, 79 insertions, 0 deletions

diff --git a/cards/mtcos_card.py b/cards/mtcos_card.py
index e4335cf..b5cc561 100644
--- a/cards/mtcos_card.py
+++ b/cards/mtcos_card.py
@@ -14,3 +14,82 @@ class MTCOS_Card(ISO_7816_4_Card,building_blocks.Card_with_80_aa):
         "list_files": building_blocks.Card_with_80_aa.cmd_listfiles,
         "ls": building_blocks.Card_with_80_aa.cmd_list,
         }
+
+    def decode_auth_scheme(value):
+        return " (0x%02x) " % ord(value) + { 
+            0x1: "MaskTech scheme",
+            0x2: "NETLINK compatible",
+            0x4: "ICAO - basic access control",
+        }.get(ord(value), "RFU")
+    
+    reset_retry_counter_byte_descriptions = (
+        (0xFF, 0x00, None, "Retry counter is unused"),
+        (0x80, 0x00, None, "Retry counter is reset upon successful both Authentication and RESET RETRY COUNTER"),
+        (0x80, 0x80, None, "Retry counter can only be reset using RESET RETRY COUNTER"),
+    )
+    def decode_retry_counter(value):
+        results = [" %s" % utils.hexdump(value, short=True)]
+        results.append("Number of further allowed attempts: %i" % ord(value[0]))
+        results.append("New value of the retry counter: %i\n\t%s" % (
+            ord(value[1]) % 0x7F,
+            "\n\t".join( utils.parse_binary( 
+                ord(value[1]), MTCOS_Card.reset_retry_counter_byte_descriptions, True 
+            ) )
+        ) )
+        return "\n".join(results)
+    
+    application_class_byte_descriptions = (
+        (0x80, 0x80, None, "Secret file"),
+        (0xC0, 0x80, None, "RFU"),
+        (0xC0, 0xC0, None, "Keyfile"),
+        (0xC8, 0xC8, None, "Possible application area: Signature"),
+        (0xC4, 0xC4, None, "Possible application area: Encryption"),
+        (0xC2, 0xC2, None, "Possible application area: Cryptographic checksum (Secure Messaging)"),
+        (0xC1, 0xC1, None, "Possible application area: Authentication"),
+    )
+    cryptographic_algorithm_byte_descriptions = (
+        (0x80, 0x00, None, "Symmetric Algorithm"),
+        (0x8F, 0x08, None, "DES-Key"),
+        (0x8E, 0x0C, None, "3DES-Key (Triple DES with 2 or 3 keys)"),
+        (0x81, 0x00, None, " - ECB"),
+        (0x81, 0x01, None, " - CBC"),
+        (0x80, 0x80, None, "Asymmetric Algorithm"),
+        (0xC0, 0x80, None, "Private Key"),
+        (0xB0, 0x80, None, "RSA"),
+        (0xB1, 0x81, None, " - Raw"),
+        (0xB2, 0x82, None, " - PKCS#1 type 2 and 2"),
+        (0xB4, 0x84, None, " - ISO/IEC 9796-2"),
+    )
+    def decode_83(value):
+        ## 0x83 in 0xA5 is either "Cryptographic algorithm and allowed applications" or
+        ##  "Default key reference for authentication commands in this environment"
+        
+        if len(value) >= 2:
+            results = [" %s" % utils.hexdump(value, short=True)]
+            results.append("Application class: 0x%02x\n\t%s" % (
+                ord(value[0]),
+                "\n\t".join( utils.parse_binary( 
+                    ord(value[0]), MTCOS_Card.application_class_byte_descriptions, True 
+                ) )
+            ) )
+            results.append("Cryptographic algorithm: 0x%02x\n\t%s" % (
+                ord(value[1]),
+                "\n\t".join( utils.parse_binary( 
+                    ord(value[1]), MTCOS_Card.cryptographic_algorithm_byte_descriptions, True 
+                ) )
+            ) )
+            return "\n".join(results)
+        elif len(value) == 1:
+            return "\nDefault key reference for authentication commands in this environment: 0x%02x" % ord(value[0])
+    
+    TLV_utils.identifier("context_A5")
+    TLV_OBJECTS = {
+        TLV_utils.context_FCP: {
+            0xA5: (TLV_utils.recurse, "Proprietary security attributes", context_A5),
+        },
+        context_A5: {
+            0x81: (decode_auth_scheme, "Authentication scheme"),
+            0x82: (decode_retry_counter, "Retry counter"),
+            0x83: (decode_83, "Cryptographic algorithm and allowed applications OR Default key reference"),
+        }
+    }