From 0b53094927d746c351f503b40b33b07d0ea72ef3 Mon Sep 17 00:00:00 2001
From: Brian Warner <warner@lothar.com>
Date: Sat, 28 May 2016 18:30:36 -0700
Subject: [PATCH] INCOMPATIBILITY: send pake message as dict, not raw bytes

This gives us room in the future to put other keys there, like one which
says we want to use Noise for the phase-message encryption instead of
our current HKDF scheme.
---
 src/wormhole/test/test_wormhole.py | 21 ++++++++++++++-------
 src/wormhole/wormhole.py           |  8 ++++++--
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/wormhole/test/test_wormhole.py b/src/wormhole/test/test_wormhole.py
index efff68e..820f058 100644
--- a/src/wormhole/test/test_wormhole.py
+++ b/src/wormhole/test/test_wormhole.py
@@ -10,6 +10,8 @@ from .. import wormhole
 from ..errors import WrongPasswordError, WelcomeError, UsageError
 from spake2 import SPAKE2_Symmetric
 from ..timing import DebugTiming
+from ..util import (bytes_to_dict, dict_to_bytes,
+                    hexstr_to_bytes, bytes_to_hexstr)
 from nacl.secret import SecretBox
 
 APPID = u"appid"
@@ -149,9 +151,8 @@ class Basic(unittest.TestCase):
         sp2 = SPAKE2_Symmetric(wormhole.to_bytes(code),
                                idSymmetric=wormhole.to_bytes(APPID))
         msg2 = sp2.start()
-        msg2_hex = hexlify(msg2).decode("ascii")
         key = sp2.finish(msg1)
-        return key, msg2_hex
+        return key, msg2
 
     def test_create(self):
         wormhole._Wormhole(APPID, u"relay_url", reactor, None, None)
@@ -219,11 +220,16 @@ class Basic(unittest.TestCase):
                  side=w._side)
         self.assertNoResult(v)
 
+        # extract our outbound PAKE message
+        body = bytes_to_dict(hexstr_to_bytes(out[1][u"body"]))
+        msg1 = hexstr_to_bytes(body[u"pake_v1"])
+
         # next we build the simulated peer's PAKE operation
         side2 = w._side + u"other"
-        msg1 = unhexlify(out[1][u"body"].encode("ascii"))
-        key, msg2_hex = self.make_pake(CODE, side2, msg1)
-        response(w, type=u"message", phase=u"pake", body=msg2_hex, side=side2)
+        key, msg2 = self.make_pake(CODE, side2, msg1)
+        payload = {u"pake_v1": bytes_to_hexstr(msg2)}
+        body_hex = bytes_to_hexstr(dict_to_bytes(payload))
+        response(w, type=u"message", phase=u"pake", body=body_hex, side=side2)
 
         # hearing the peer's PAKE (msg2) makes us release the nameplate, send
         # the confirmation message, and sends any queued phase messages. It
@@ -638,8 +644,9 @@ class Basic(unittest.TestCase):
 
         sp2 = SPAKE2_Symmetric(b"", idSymmetric=wormhole.to_bytes(APPID))
         msg2 = sp2.start()
-        msg2_hex = hexlify(msg2).decode("ascii")
-        response(w, type=u"message", phase=u"pake", body=msg2_hex, side=u"s2")
+        payload = {u"pake_v1": bytes_to_hexstr(msg2)}
+        body_hex = bytes_to_hexstr(dict_to_bytes(payload))
+        response(w, type=u"message", phase=u"pake", body=body_hex, side=u"s2")
         self.assertNoResult(d1)
         self.assertNoResult(d2) # verify() waits for confirmation
 
diff --git a/src/wormhole/wormhole.py b/src/wormhole/wormhole.py
index 090e2dd..b96d6c7 100644
--- a/src/wormhole/wormhole.py
+++ b/src/wormhole/wormhole.py
@@ -538,12 +538,16 @@ class _Wormhole:
                 and self._mailbox_state == OPEN
                 and self._flag_need_to_send_PAKE):
             return
-        self._msg_send(u"pake", self._msg1)
+        body = {u"pake_v1": bytes_to_hexstr(self._msg1)}
+        payload = dict_to_bytes(body)
+        self._msg_send(u"pake", payload)
         self._flag_need_to_send_PAKE = False
 
     def _event_received_pake(self, pake_msg):
+        payload = bytes_to_dict(pake_msg)
+        msg2 = hexstr_to_bytes(payload[u"pake_v1"])
         with self._timing.add("pake2", waiting="crypto"):
-            self._key = self._sp.finish(pake_msg)
+            self._key = self._sp.finish(msg2)
         self._event_established_key()
 
     def _event_established_key(self):