Latest Ultrix

Author: gdanezis

requirements.txt

@@ -1,5 +1,5 @@
 future>=0.14.3
 pytest>=2.5.0
 msgpack-python>=0.4.6
-petlib>=0.0.38
+petlib>=0.0.41
 pynacl>=1.1.0

setup.py

@@ -23,14 +23,14 @@
                   "future >= 0.14.3",
                   "pytest >= 3.0.0",
                   "msgpack-python >= 0.4.6",
-                  "petlib >= 0.0.38",
+                  "petlib >= 0.0.41",
                   "pynacl >= 1.1.0",
             ],
             install_requires=[
                   "future >= 0.14.3",
                   "pytest >= 3.0.0",
                   "msgpack-python >= 0.4.6",
-                  "petlib >= 0.0.38",
+                  "petlib >= 0.0.41",
                   "pynacl >= 1.1.0",
             ]
       )

sphinxmix/SphinxParams.py

@@ -94,6 +94,10 @@ def test_params():
     c = params.aes_ctr(k, b"Hello World!")
     assert params.aes_ctr(k, c) == b"Hello World!"
 
+    c = params.small_perm(b"\x00"*16, b"\x00"*16)
+    c2 = params.small_perm_inv(b"\x00"*16, c)
+    assert c2 == b"\x00"*16
+
 class SphinxParams:
 
     def __init__(self, group=None, header_len = 192, body_len = 1024, assoc_len=0, k=16):
@@ -193,6 +197,22 @@ def pii(self, key, data):
 
         return self.lioness_dec(key, data)
 
+    def small_perm(self, key, data):
+        assert len(data) == self.k
+        aes = Cipher("AES-128-ECB")
+        enc = aes.enc(key, None)
+        c = enc.update(data)
+        c += enc.finalize()
+        return c
+
+    def small_perm_inv(self, key, data):
+        assert len(data) == self.k
+        aes = Cipher("AES-128-ECB")
+        enc = aes.dec(key, None)
+        c = enc.update(data)
+        c += enc.finalize()
+        return c
+
     # The various hashes
     def hash(self, data):
         return sha256(data).digest()

sphinxmix/UltrixClient.py

@@ -39,7 +39,7 @@
 from .SphinxClient import pack_message, unpack_message
 
 
-def create_header(params, nodelist, keys, dest, assoc=None, secrets = None, gamma=None):
+def create_header(params, nodelist, keys, dest, assoc=None, secrets = None, gamma=None, dest_key = None):
     """ Internal function, creating a Sphinx header.""" 
 
     node_meta = [pack("b", len(n)) + n for n in nodelist]
@@ -68,6 +68,9 @@ def create_header(params, nodelist, keys, dest, assoc=None, secrets = None, gamm
     if not gamma:
         gamma = urandom(16)
 
+    if not dest_key:
+        dest_key = urandom(p.k)
+
     asbtuples = []
 
     for k in keys:
@@ -119,13 +122,15 @@ def create_header(params, nodelist, keys, dest, assoc=None, secrets = None, gamm
         beta_all = [ beta ] + beta_all
 
     # Compute the cummulative MAC.
-
     original_gamma = gamma
     new_keys = []
     for beta_i, k in zip(beta_all, asbtuples):
         gamma = p.mu(p.hmu(k.aes), gamma + beta_i)
         new_keys += [p.derive_key(k.aes, gamma)]
 
+    # Encrypt the dest key
+    
+
     return (asbtuples[0].alpha, beta, original_gamma), new_keys