Public key bbs98

nkms/crypto/__init__.py

@@ -26,6 +26,7 @@ def symmetric_from_algorithm(algorithm):
 def pre_from_algorithm(algorithm):
     kw = {k: v for k, v in algorithm['pre'].items()
           if k != 'cipher' and v is not None}
-    module = importlib('nkms.crypto.block.' + algorithm['pre']['cipher'])
+    module = importlib.import_module(
+            'nkms.crypto.block.' + algorithm['pre']['cipher'])
     # TODO need to cache this
     return module.PRE(**kw)

nkms/crypto/pre/bbs98.py

@@ -36,4 +36,10 @@ class PRE(BasePRE):
         return msgpack.dumps([2, epriv, remsg])  # type 2 emsg
 
     def decrypt(self, priv, emsg, padding=True):
-        pass
+        # This is non-optimal b/c of double-deserialization
+        # but this cipher is for development/tests, not production
+        # so be it
+        emsg_l = msgpack.unpack(emsg)
+        if emsg_l[0] == 2:
+            _, priv, emsg = emsg_l
+        return super(PRE, self).decrypt(priv, emsg, padding=padding)

tests/test_default_crypto.py

@@ -17,3 +17,16 @@ def test_symmetric():
 
 def test_pre():
     pre = pre_from_algorithm(default_algorithm)
+    sk_a = b'a' * 32
+    sk_b = b'b' * 32
+    pk_a = pre.priv2pub(sk_a)
+    pk_b = pre.priv2pub(sk_b)
+    msg = b'Hello world'
+    rk_ab = pre.rekey(sk_a, pk_b)
+
+    emsg_a = pre.encrypt(pk_a, msg)
+    emsg_b = pre.reencrypt(rk_ab, emsg_a)
+
+    assert pre.decrypt(sk_a, emsg_a) == msg
+    assert pre.decrypt(sk_b, emsg_a) != msg
+    assert pre.decrypt(sk_b, emsg_b) == msg