Added updated bindings for key exchange API. Added tests.

libnacl/__init__.py

@@ -1115,6 +1115,8 @@ def randombytes_uniform(upper_bound):
     '''
     return nacl.randombytes_uniform(upper_bound)
 
+# Key derivation API 
+
 def crypto_kdf_keygen():
     '''
     Returns a string of random bytes to generate a master key
@@ -1134,6 +1136,8 @@ def crypto_kdf_derive_from_key(subkey_size, subkey_id, context, master_key):
     nacl.crypto_kdf_derive_from_key(buf, subkey_size, subkey_id, context, master_key)
     return buf.raw
 
+# Key Exchange API
+
 def crypto_kx_keypair():
     '''
     Generate and return a new keypair
@@ -1154,7 +1158,7 @@ def crypto_kx_seed_keypair(seed):
     nacl.crypto_kx_seed_keypair(pk, sk, seed)
     return pk.raw, sk.raw
 
-def crypto_kx_client_session_keys(rx, tx, client_pk, client_sk, server_pk):
+def crypto_kx_client_session_keys(client_pk, client_sk, server_pk):
     '''
     Computes a pair of shared keys (rx and tx) using the client's public key client_pk, 
     the client's secret key client_sk and the server's public key server_pk.
@@ -1163,9 +1167,9 @@ def crypto_kx_client_session_keys(rx, tx, client_pk, client_sk, server_pk):
     rx = ctypes.create_string_buffer(crypto_kx_SESSIONKEYBYTES)
     tx = ctypes.create_string_buffer(crypto_kx_SESSIONKEYBYTES)
     status = nacl.crypto_kx_client_session_keys(rx, tx, client_pk, client_sk, server_pk)
-    return rx, tx, status
+    return rx.raw, tx.raw, status
 
-def crypto_kx_server_session_keys(rx, tx, server_pk, server_sk, client_pk):
+def crypto_kx_server_session_keys(server_pk, server_sk, client_pk):
     '''
     Computes a pair of shared keys (rx and tx) using the server's public key server_pk, 
     the server's secret key server_sk and the client's public key client_pk.

tests/unit/test_raw_random.py

@@ -51,7 +51,6 @@ def test_crypto_kdf_keygen(self):
         self.assertEqual(32, len(master_key))
         self.assertTrue(all(freq.values()))
 
-
     def test_crypto_kdf_derive_from_key(self):
 
       master_key = libnacl.crypto_kdf_keygen()
@@ -65,4 +64,41 @@ def test_crypto_kdf_derive_from_key(self):
       self.assertEqual(subkey, subkey2)
       self.assertNotEqual(subkey, subkey3)
 
-
+    def test_crypto_kx_keypair(self):
+      pk, sk = libnacl.crypto_kx_keypair()
+      self.assertEqual(32, len(pk))
+      self.assertEqual(32, len(sk))
+
+    def test_crypto_kx_seed_keypair(self):
+      seed = libnacl.randombytes_buf(32)
+      seed2 = libnacl.randombytes_buf(32)
+      pk, sk = libnacl.crypto_kx_seed_keypair(seed)
+      pk2, sk2 = libnacl.crypto_kx_seed_keypair(seed)
+      pk3, sk3 = libnacl.crypto_kx_seed_keypair(seed2)
+
+      self.assertEqual(pk, pk2)
+      self.assertNotEqual(pk, pk3)
+      self.assertEqual(sk, sk2)
+      self.assertNotEqual(sk, sk3)
+
+    def test_crypto_kx_client_session_keys(self):
+      client_pk, client_sk = libnacl.crypto_kx_keypair()
+      server_pk, server_sk = libnacl.crypto_kx_keypair()
+      rx, tx, status = libnacl.crypto_kx_client_session_keys(client_pk, client_sk, server_pk)
+      rx2, tx2, status = libnacl.crypto_kx_client_session_keys(client_pk, client_sk, server_pk)
+
+      self.assertEqual(32, len(rx))
+      self.assertEqual(32, len(tx))
+      self.assertEqual(rx, rx2)
+      self.assertEqual(tx, tx2)
+
+    def test_crypto_kx_server_session_keys(self):
+      client_pk, client_sk = libnacl.crypto_kx_keypair()
+      server_pk, server_sk = libnacl.crypto_kx_keypair()
+      rx, tx, status = libnacl.crypto_kx_server_session_keys(client_pk, client_sk, server_pk)
+      rx2, tx2, status = libnacl.crypto_kx_server_session_keys(client_pk, client_sk, server_pk)
+
+      self.assertEqual(32, len(rx))
+      self.assertEqual(32, len(tx))
+      self.assertEqual(rx, rx2)
+      self.assertEqual(tx, tx2)