@@ -274,6 +274,11 @@ def simplify_keytab(keytab):

 		simplified['entries'].append(simple_entry)

 	return simplified

+def to_bytes(value):

+	if type(value) is bytes:

+		return value

+	return unhexlify(value)

+

 def prepare_serialization(obj):

 	"""

 	Prepare keytab for serialization.

@@ -343,7 +348,7 @@ def raw_entry_to_binary(entry, index):

 			raise KeytabComposingError('invalid %s data in entry #%d' % (key, index))

 	data = raw_principal_to_binary(entry['principal'], index)

 	try:

-		key_data = unhexlify(entry['key'])

+		key_data = to_bytes(entry['key'])

 	except:

 		raise KeytabComposingError('invalid key data in entry #%d' % index)

 	data += struct.pack('>IBHH', entry['timestamp'], entry['kvno'], entry['enctype_raw'], len(key_data))

@@ -357,7 +362,7 @@ def raw_record_to_binary(record, index):

 	data += raw_entry_to_binary(record['entry'], index)

 	if 'tail' in record:

 		try:

-			data += unhexlify(record['tail'])

+			data += to_bytes(record['tail'])

 		except:

 			raise KeytabComposingError('invalid tail data in record #%d' % index)

 	return struct.pack('>i', len(data)) + data

@@ -375,7 +380,7 @@ def raw_hole_to_binary(hole, index):

 		raise KeytabComposingError('invalid length in record #%d' % index)

 	if 'data' in record:

 		try:

-			hole_data = unhexlify(record['data'])

+			hole_data = to_bytes(record['data'])

 		except:

 			raise KeytabComposingError('invalid data in record #%d' % index)

 		if len(hole_data) != length:

@@ -432,7 +437,7 @@ def simple_kvno_to_full(inentry, index, entry, record):

 		entry['kvno'] = 0 if kvno_too_big else inentry['kvno']

 		if inentry.get('kvno_in_tail', False):

 			entry['tail_kvno'] = inentry['kvno']

-			record['tail'] = hexlify(struct.pack('>I', inentry['kvno']))

+			record['tail'] = struct.pack('>I', inentry['kvno'])

 		elif kvno_too_big:

 			message = 'Cannot store kvno > 255 without kvno_in_tail in entry #%d'

 			raise KeytabComposingError(message % index)

@@ -478,7 +483,7 @@ def simple_keytab_to_full(indata):

 		simple_enctype_to_full(inentry, index, entry)

 		if 'key' in inentry:

 			entry['key'] = inentry['key']

-			entry['key_length'] = len(unhexlify(inentry['key']))

+			entry['key_length'] = len(to_bytes(inentry['key']))

 		data['records'].append(record)

 	return data