Moving echo-script related code into suitable directory

Adding Empty class and switching some Nones to it where required by specification
Some additions to CipherState

noise/constants.py

@@ -1,49 +1,2 @@
-from enum import Enum
-
-
-class PSK(Enum):
-    PSK_DISABLED = 0x00
-    PSK_ENABLED = 0x01
-
-
-class PATTERN(Enum):
-    PATTERN_NN = 0x00
-    PATTERN_KN = 0x01
-    PATTERN_NK = 0x02
-    PATTERN_KK = 0x03
-    PATTERN_NX = 0x04
-    PATTERN_KX = 0x05
-    PATTERN_XN = 0x06
-    PATTERN_IN = 0x07
-    PATTERN_XK = 0x08
-    PATTERN_IK = 0x09
-    PATTERN_XX = 0x0A
-    PATTERN_IX = 0x0B
-    PATTERN_HFS = 0x80
-
-
-class CIPHER(Enum):
-    CIPHER_CHACHAPOLY = 0x00
-    CIPHER_AESGCM = 0x01
-
-
-class DH(Enum):
-    DH_25519 = 0x00
-    DH_448 = 0x01
-    DH_NEWHOPE = 0x02
-    DH_MASK = 0x0F
-
-
-class HYBRID(Enum):
-    HYBRID_NONE = 0x00
-    HYBRID_25519 = 0x10
-    HYBRID_448 = 0x20
-    HYBRID_NEWHOPE = 0x30
-    HYBRID_MASK = 0xF0
-
-
-class HASH(Enum):
-    HASH_SHA256 = 0x00
-    HASH_SHA512 = 0x01
-    HASH_BLAKE2s = 0x02
-    HASH_BLAKE2b = 0x03
+class Empty:
+    pass

noise/echo/client_script.py

@@ -1,12 +1,8 @@
-import base64
-import socket
-
 import logging
+import socket
 import struct
 
-import nacl
-
-from noise.constants import *
+from noise.echo.echo_constants import PSK, PATTERN, CIPHER, DH, HASH
 
 logger = logging.getLogger(__name__)
 

noise/echo/echo_constants.py

@@ -0,0 +1,49 @@
+from enum import Enum
+
+
+class PSK(Enum):
+    PSK_DISABLED = 0x00
+    PSK_ENABLED = 0x01
+
+
+class PATTERN(Enum):
+    PATTERN_NN = 0x00
+    PATTERN_KN = 0x01
+    PATTERN_NK = 0x02
+    PATTERN_KK = 0x03
+    PATTERN_NX = 0x04
+    PATTERN_KX = 0x05
+    PATTERN_XN = 0x06
+    PATTERN_IN = 0x07
+    PATTERN_XK = 0x08
+    PATTERN_IK = 0x09
+    PATTERN_XX = 0x0A
+    PATTERN_IX = 0x0B
+    PATTERN_HFS = 0x80
+
+
+class CIPHER(Enum):
+    CIPHER_CHACHAPOLY = 0x00
+    CIPHER_AESGCM = 0x01
+
+
+class DH(Enum):
+    DH_25519 = 0x00
+    DH_448 = 0x01
+    DH_NEWHOPE = 0x02
+    DH_MASK = 0x0F
+
+
+class HYBRID(Enum):
+    HYBRID_NONE = 0x00
+    HYBRID_25519 = 0x10
+    HYBRID_448 = 0x20
+    HYBRID_NEWHOPE = 0x30
+    HYBRID_MASK = 0xF0
+
+
+class HASH(Enum):
+    HASH_SHA256 = 0x00
+    HASH_SHA512 = 0x01
+    HASH_BLAKE2s = 0x02
+    HASH_BLAKE2b = 0x03

noise/state.py

@@ -1,25 +1,29 @@
+from noise.constants import Empty
+
+
 class CipherState(object):
     """
     
     """
     def __init__(self):
-        self.k = None
+        self.k = Empty()
         self.n = None
 
     def initialize_key(self, key):
         """
-        
-        :param key: 
+
+        :param key:
         :return: 
         """
-        pass
+        self.k = key
+        self.n = 0
 
     def has_key(self):
         """
         
-        :return: 
+        :return: True if self.k is not an instance of Empty
         """
-        return self.k is not None
+        return not isinstance(self.k, Empty)
 
     def encrypt_with_ad(self, ad, plaintext):
         """
@@ -98,13 +102,14 @@ class HandshakeState(object):
     
     """
     def __init__(self):
+        self.symmetric_state = Empty()
         self.handshake_pattern = None
         self.initiator = None
         self.prologue = b''
-        self.s = None
-        self.e = None
-        self.rs = None
-        self.re = None
+        self.s = Empty()
+        self.e = Empty()
+        self.rs = Empty()
+        self.re = Empty()
 
     def initialize(self, handshake_pattern, initiator, prologue=b'', s=None, e=None, rs=None, re=None):
         """