implemented most of the base objects

kasten/__init__.py

@@ -0,0 +1,4 @@
+from . import exceptions
+from . import generator
+from . import types
+from .main import Kasten

kasten/exceptions/__init__.py

@@ -7,3 +7,7 @@ class InvalidKastenTypeLength(KastenException):
 
 class InvalidEncryptionMode(KastenException):
     pass
+
+class InvalidID(KastenException):
+    pass
+

kasten/generator/__init__.py

@@ -0,0 +1,19 @@
+from kasten.types import KastenPacked
+from kasten.types import KastenChecksum
+from kasten.exceptions import InvalidID
+
+from hashlib import sha3_384
+from ..main import Kasten
+
+
+class KastenBaseGenerator:
+    @classmethod
+    def generate(cls, packed_bytes: KastenPacked) -> Kasten:
+        return Kasten(sha3_384(packed_bytes).digest(), packed_bytes, cls,
+                      auto_check_generator=False)
+
+    @staticmethod
+    def validate_id(hash: KastenChecksum, packed_bytes: KastenPacked) -> None:
+        if not sha3_384(packed_bytes).digest() == hash:
+            raise InvalidID
+        return None

kasten/generator/pack.py

@@ -10,15 +10,22 @@ encrypted with specified mode:
 data: bytes
 
 """
+from math import floor
+from time import time
+
 from msgpack import packb
 
-from .. import exceptions
+from kasten import exceptions
+
+from kasten.types import KastenPacked
 
 
 def pack(data: bytes, data_type: 'KastenDataType',
          enc_mode: 'KastenEncryptionModeID',
          signer: bytes = None, signature: bytes = None,
-         app_metadata: 'KastenSerializeableDict' = None) -> 'PreparedKasten':
+         app_metadata: 'KastenSerializeableDict' = None,
+         timestamp: int = None
+         ) ->  KastenPacked:
 
     # Ensure data type does not exceed 4 characters
     if not data_type or len(data_type) > 4:
@@ -31,13 +38,17 @@ def pack(data: bytes, data_type: 'KastenDataType',
         raise exceptions.InvalidEncryptionMode
     if not enc_mode >= 0 or enc_mode >= 100:
         raise exceptions.InvalidEncryptionMode
-    
+
     try:
         data = data.encode('utf8')
     except AttributeError:
         pass
+    if timestamp is None:
+        timestamp = floor(time())
+    assert int(timestamp)
 
-    kasten_header = [data_type, enc_mode]
+
+    kasten_header = [data_type, enc_mode, timestamp]
     if signer:
         if signature is None:
             raise ValueError("Signer specified without signature")

kasten/main.py

@@ -0,0 +1,17 @@
+from .types import KastenChecksum
+from .types import KastenPacked
+
+
+class Kasten:
+    def __init__(self, id: KastenChecksum,
+                 packed_bytes: KastenPacked,
+                 generator: 'KastenBaseGenerator',
+                 auto_check_generator = False):  # noqa
+        if auto_check_generator:
+            generator.validate_id(id, packed_bytes)
+        self.id = id
+        self.packed_bytes = packed_bytes
+        self.generator = generator
+
+    def check_generator(self):
+        self.generator.validate_id(self.id, self.packed_bytes)

kasten/types.py

@@ -1,2 +1,18 @@
+from typing import Tuple
+from typing import NewType
+from typing import NamedTuple
+
+KastenDataType = NewType('KastenDataType', str)
+
 class KastenDataType(str):
+
     pass
+
+
+class KastenPacked(bytes):
+    """Raw Kasten bytes that have not yet been passed through a KastenGenerator"""
+
+
+class KastenChecksum(bytes):
+    """hash or checksum of a Kasten object"""
+

tests/test_generator_base.py

@@ -0,0 +1,18 @@
+import unittest
+from hashlib import sha3_384
+
+from kasten import exceptions
+from kasten.generator import KastenBaseGenerator
+
+
+class TestBaseGenerator(unittest.TestCase):
+    def test_base_generator(self):
+        k = b'\x92\xa3bin\x00\xc4\x01\n(\x86!\xd7\xb5\x8ar\xae\x97z'
+        K = KastenBaseGenerator.generate(k)
+        h = sha3_384(k).digest()
+        self.assertTrue(len(K.packed_bytes) > 0)
+        KastenBaseGenerator.validate_id(h, k)
+        self.assertRaises(exceptions.InvalidID, KastenBaseGenerator.validate_id, h, b"\x92\xa3txt\x00\xc4\x01\n(\x86!\xd7\xb5\x8ar\xae\x97z")
+
+
+unittest.main()

tests/test_kasten.py

@@ -0,0 +1,14 @@
+import unittest
+from kasten import Kasten
+from hashlib import sha3_384
+
+from kasten import exceptions
+from kasten.generator import KastenBaseGenerator
+
+
+class TestKasten(unittest.TestCase):
+    def test_kasten(self):
+        k = b'\x92\xa3bin\x00\xc4\x01\n(\x86!\xd7\xb5\x8ar\xae\x97z'
+
+
+unittest.main()

tests/test_pack.py

@@ -1,7 +1,7 @@
 import unittest
 import os
 
-from kasten import pack
+from kasten.generator import pack
 from kasten import exceptions
 
 
@@ -11,14 +11,14 @@ class TestPack(unittest.TestCase):
         data = os.urandom(10)
         packed = pack.pack(data, 'bin', 0)
         parts = packed.split(b'\n', 1)
-        self.assertEqual(parts[0], b'\x92\xa3bin\x00\xc4\x01')
+        self.assertEqual(parts[0], b'\x93\xa3bin\x00\xce^\x95\x82:\xc4\x01')
         self.assertEqual(parts[1], data)
 
     def test_linebreak_data(self):
         data = os.urandom(9) + b'\n' + b"okay"
         packed = pack.pack(data, 'bin', 0)
         parts = packed.split(b'\n', 1)
-        self.assertEqual(parts[0], b'\x92\xa3bin\x00\xc4\x01')
+        self.assertEqual(parts[0], b'\x93\xa3bin\x00\xce^\x95\x82:\xc4\x01')
         self.assertEqual(parts[1], data)
 
     def test_invalid_data_type(self):