gpg-migrate.py: Convert PGPPacket 'packet-tag' key to 'type'

And convert the integer to a string using the table from RFC 4880 [1]:

  The packet tag denotes what type of packet the body holds.  Note
  that old format headers can only have tags less than 16, whereas new
  format headers can have tags as great as 63.  The defined tags (in
  decimal) are as follows:

       0        -- Reserved - a packet tag MUST NOT have this value
       1        -- Public-Key Encrypted Session Key Packet
       2        -- Signature Packet
       3        -- Symmetric-Key Encrypted Session Key Packet
       4        -- One-Pass Signature Packet
       5        -- Secret-Key Packet
       6        -- Public-Key Packet
       7        -- Secret-Subkey Packet
       8        -- Compressed Data Packet
       9        -- Symmetrically Encrypted Data Packet
       10       -- Marker Packet
       11       -- Literal Data Packet
       12       -- Trust Packet
       13       -- User ID Packet
       14       -- Public-Subkey Packet
       17       -- User Attribute Packet
       18       -- Sym. Encrypted and Integrity Protected Data Packet
       19       -- Modification Detection Code Packet
       60 to 63 -- Private or Experimental Values

[1]: http://tools.ietf.org/search/rfc4880#section-4.3

diff --git a/gpg-migrate.py b/gpg-migrate.py
index 699b560ad4f2ace744173d6c92788c2220d138b2..c41ddd46a7a2252e120395e8796e372fbf61715b 100755 (executable)
--- a/gpg-migrate.py
+++ b/gpg-migrate.py
@@ -25,6 +25,31 @@ class PGPPacket (dict):
         3: (None, None),
         }
 
+    _packet_types = {
+        0: 'reserved',
+        1: 'public-key encrypted session key packet',
+        2: 'signature packet',
+        3: 'symmetric-key encrypted session key packet',
+        4: 'one-pass signature packet',
+        5: 'secret-key packet',
+        6: 'public-key packet',
+        7: 'secret-subkey packet',
+        8: 'compressed data packet',
+        9: 'symmetrically encrypted data packet',
+        10: 'marker packet',
+        11: 'literal data packet',
+        12: 'trust packet',
+        13: 'user id packet',
+        14: 'public-subkey packet',
+        17: 'user attribute packet',
+        18: 'sym. encrypted and integrity protected data packet',
+        19: 'modification detection code packet',
+        60: 'private',
+        61: 'private',
+        62: 'private',
+        63: 'private',
+        }
+
     def from_bytes(self, data):
         offset = self._parse_header(data=data)
         packet = data[offset:offset + self['length']]
@@ -42,10 +67,10 @@ class PGPPacket (dict):
             raise ValueError('most significant packet tag bit not set')
         self['new-format'] = packet_tag & 1 << 6
         if self['new-format']:
-            self['packet-tag'] = packet_tag & 0b111111
+            type_code = packet_tag & 0b111111
             raise NotImplementedError('new-format packet length')
         else:
-            self['packet-tag'] = packet_tag >> 2 & 0b1111
+            type_code = packet_tag >> 2 & 0b1111
             self['length-type'] = packet_tag & 0b11
             length_bytes, length_type = self._old_format_packet_length_type[
                 self['length-type']]
@@ -56,6 +81,7 @@ class PGPPacket (dict):
             length_data = data[offset: offset + length_bytes]
             offset += length_bytes
             self['length'] = _struct.unpack(length_format, length_data)[0]
+        self['type'] = self._packet_types[type_code]
         return offset
 
     def to_bytes(self):