Merge pull request #99 from web-push-libs/feat/97

Fixup aes128gcm key injection

Author: jrconlin

pywebpush/__init__.py

@@ -181,33 +181,42 @@ def encode(self, data, content_encoding="aes128gcm"):
             raise WebPushException("Invalid content encoding specified. "
                                    "Select from " +
                                    json.dumps(self.valid_encodings))
-        if (content_encoding == "aesgcm"):
+        if content_encoding == "aesgcm":
             salt = os.urandom(16)
         # The server key is an ephemeral ECDH key used only for this
         # transaction
         server_key = ec.generate_private_key(ec.SECP256R1, default_backend())
-        crypto_key = base64.urlsafe_b64encode(
-            server_key.public_key().public_numbers().encode_point()
-        ).strip(b'=')
+        crypto_key = server_key.public_key().public_numbers().encode_point()
 
         if isinstance(data, six.string_types):
             data = bytes(data.encode('utf8'))
-
-        encrypted = http_ece.encrypt(
-            data,
-            salt=salt,
-            keyid=crypto_key.decode(),
-            private_key=server_key,
-            dh=self.receiver_key,
-            auth_secret=self.auth_key,
-            version=content_encoding)
-
-        reply = CaseInsensitiveDict({
-            'crypto_key': crypto_key,
-            'body': encrypted,
-        })
-        if salt:
-            reply['salt'] = base64.urlsafe_b64encode(salt).strip(b'=')
+        if content_encoding == "aes128gcm":
+            encrypted = http_ece.encrypt(
+                data,
+                salt=salt,
+                private_key=server_key,
+                dh=self.receiver_key,
+                auth_secret=self.auth_key,
+                version=content_encoding)
+            reply = CaseInsensitiveDict({
+                'body': encrypted
+            })
+        else:
+            crypto_key = base64.urlsafe_b64encode(crypto_key).strip(b'=')
+            encrypted = http_ece.encrypt(
+                data,
+                salt=salt,
+                private_key=server_key,
+                keyid=crypto_key.decode(),
+                dh=self.receiver_key,
+                auth_secret=self.auth_key,
+                version=content_encoding)
+            reply = CaseInsensitiveDict({
+                'crypto_key': crypto_key,
+                'body': encrypted,
+            })
+            if salt:
+                reply['salt'] = base64.urlsafe_b64encode(salt).strip(b'=')
         return reply
 
     def as_curl(self, endpoint, encoded_data, headers):
@@ -236,7 +245,7 @@ def as_curl(self, endpoint, encoded_data, headers):
             data = "--data-binary @encrypted.data"
         if 'content-length' not in headers:
             header_list.append(
-                '-H "content-length: {}" \\ \n'.format(len(data)))
+                '-H "content-length: {}" \\ \n'.format(len(encoded_data)))
         return ("""curl -vX POST {url} \\\n{headers}{data}""".format(
             url=endpoint, headers="".join(header_list), data=data))
 
@@ -272,23 +281,28 @@ def send(self, data=None, headers=None, ttl=0, gcm_key=None, reg_id=None,
         encoded = {}
         headers = CaseInsensitiveDict(headers)
         if data:
-            encoded = self.encode(data)
-            # Append the p256dh to the end of any existing crypto-key
-            crypto_key = headers.get("crypto-key", "")
-            if crypto_key:
-                # due to some confusion by a push service provider, we should
-                # use ';' instead of ',' to append the headers.
-                # see https://github.com/webpush-wg/webpush-encryption/issues/6
-                crypto_key += ';'
-            crypto_key += ("dh=" + encoded["crypto_key"].decode('utf8'))
-            headers.update({
-                'crypto-key': crypto_key,
-                'content-encoding': content_encoding,
-            })
-            if encoded.get('salt'):
+            encoded = self.encode(data, content_encoding)
+            if "crypto_key" in encoded:
+                # Append the p256dh to the end of any existing crypto-key
+                crypto_key = headers.get("crypto-key", "")
+                if crypto_key:
+                    # due to some confusion by a push service provider, we
+                    # should use ';' instead of ',' to append the headers.
+                    # see
+                    # https://github.com/webpush-wg/webpush-encryption/issues/6
+                    crypto_key += ';'
+                crypto_key += (
+                    "dh=" + encoded["crypto_key"].decode('utf8'))
+                headers.update({
+                    'crypto-key': crypto_key
+                })
+            if "salt" in encoded:
                 headers.update({
                     'encryption': "salt=" + encoded['salt'].decode('utf8')
                 })
+            headers.update({
+                'content-encoding': content_encoding,
+            })
         if gcm_key:
             endpoint = 'https://android.googleapis.com/gcm/send'
             reg_ids = []

pywebpush/tests/test_webpush.py

@@ -100,8 +100,10 @@ def test_encode(self):
             if 'salt' in encoded:
                 raw_salt = base64.urlsafe_b64decode(
                     push._repad(encoded['salt']))
-            raw_dh = base64.urlsafe_b64decode(
-                push._repad(encoded['crypto_key']))
+            raw_dh = None
+            if content_encoding != "aes128gcm":
+                raw_dh = base64.urlsafe_b64decode(
+                    push._repad(encoded['crypto_key']))
             raw_auth = base64.urlsafe_b64decode(
                 push._repad(subscription_info['keys']['auth']))
 
@@ -148,7 +150,8 @@ def test_send_vapid(self, mock_post):
             subscription_info=subscription_info,
             data=data,
             vapid_private_key=self.vapid_key,
-            vapid_claims={"sub": "mailto:[email protected]"}
+            vapid_claims={"sub": "mailto:[email protected]"},
+            content_encoding="aesgcm"
         )
         eq_(subscription_info.get('endpoint'), mock_post.call_args[0][0])
         pheaders = mock_post.call_args[1].get('headers')
@@ -167,7 +170,7 @@ def repad(str):
         ckey = pheaders.get('crypto-key')
         ok_('p256ecdsa=' in ckey)
         ok_('dh=' in ckey)
-        eq_(pheaders.get('content-encoding'), 'aes128gcm')
+        eq_(pheaders.get('content-encoding'), 'aesgcm')
 
     @patch.object(WebPusher, "send")
     @patch.object(py_vapid.Vapid, "sign")