feat: update to http-ece 0.6.4 (with draft-06 support)

use new "content_type" argument to specify either "aesgcm" (draft-01)
or "aes128gcm" (draft-04).

NOTE: Not all clients yet support Draft-04.

closes #33

Author: jrconlin

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 0.7.0 (2017-02-14)
+feat: update to http-ece 0.7.0 (with draft-06 support)
+feat: Allow empty payloads for send()
+feat: Add python3 classfiers & python3.6 travis tests
+feat: Add README.rst
+bug: change long to int to support python3
+
 ## 0.4.0 (2016-06-05)
 feat: make python 2.7 / 3.5 polyglot
 

README.md

@@ -1,4 +1,7 @@
 [![Build_Status](https://travis-ci.org/jrconlin/pywebpush.svg?branch=master)](https://travis-ci.org/jrconlin/pywebpush)
+[![Requirements
+Status](https://requires.io/github/web-push-libs/pywebpush/requirements.svg?branch=master)]
+
 
 # Webpush Data encryption library for Python
 

pywebpush/__init__.py

@@ -82,6 +82,11 @@ class WebPusher:
 
     """
     subscription_info = {}
+    valid_encodings = [
+        # "aesgcm128",  # this is draft-0, but DO NOT USE.
+        "aesgcm",  # draft-httpbis-encryption-encoding-01
+        "aes128gcm"  # draft-httpbis-encryption-encoding-04
+    ]
 
     def __init__(self, subscription_info):
         """Initialize using the info provided by the client PushSubscription
@@ -113,16 +118,28 @@ def _repad(self, data):
         """Add base64 padding to the end of a string, if required"""
         return data + b"===="[:len(data) % 4]
 
-    def encode(self, data):
+    def encode(self, data, content_encoding="aesgcm"):
         """Encrypt the data.
 
         :param data: A serialized block of byte data (String, JSON, bit array,
             etc.) Make sure that whatever you send, your client knows how
             to understand it.
+        :type data: str
+        :param content_encoding: The content_encoding type to use to encrypt
+            the data. Defaults to draft-01 "aesgcm". Latest draft-04 is
+            "aes128gcm", however not all clients may be able to use this
+            format.
+        :type content_encoding: enum("aesgcm", "aes128gcm")
 
         """
         # Salt is a random 16 byte array.
-        salt = os.urandom(16)
+        salt = None
+        if content_encoding not in self.valid_encodings:
+            raise WebPushException("Invalid content encoding specified. "
+                                   "Select from " +
+                                   json.dumps(self.valid_encodings))
+        if (content_encoding == "aesgcm"):
+            salt = os.urandom(16)
         # The server key is an ephemeral ECDH key used only for this
         # transaction
         server_key = pyelliptic.ECC(curve="prime256v1")
@@ -133,26 +150,31 @@ def encode(self, data):
         if isinstance(data, six.string_types):
             data = bytes(data.encode('utf8'))
 
+        key_id = server_key_id.decode('utf8')
         # http_ece requires that these both be set BEFORE encrypt or
         # decrypt is called if you specify the key as "dh".
-        http_ece.keys[server_key_id] = server_key
-        http_ece.labels[server_key_id] = "P-256"
+        http_ece.keys[key_id] = server_key
+        http_ece.labels[key_id] = "P-256"
 
         encrypted = http_ece.encrypt(
             data,
             salt=salt,
-            keyid=server_key_id,
+            keyid=key_id,
             dh=self.receiver_key,
-            authSecret=self.auth_key)
+            authSecret=self.auth_key,
+            version=content_encoding)
 
-        return CaseInsensitiveDict({
+        reply = CaseInsensitiveDict({
             'crypto_key': base64.urlsafe_b64encode(
                 server_key.get_pubkey()).strip(b'='),
-            'salt': base64.urlsafe_b64encode(salt).strip(b'='),
             'body': encrypted,
         })
+        if salt:
+            reply['salt'] = base64.urlsafe_b64encode(salt).strip(b'=')
+        return reply
 
-    def send(self, data=None, headers=None, ttl=0, gcm_key=None, reg_id=None):
+    def send(self, data=None, headers=None, ttl=0, gcm_key=None, reg_id=None,
+             content_encoding="aesgcm"):
         """Encode and send the data to the Push Service.
 
         :param data: A serialized block of data (see encode() ).

pywebpush/tests/test_webpush.py

@@ -65,32 +65,44 @@ def test_init(self):
         eq_(push.auth_key, b'\x93\xc2U\xea\xc8\xddn\x10"\xd6}\xff,0K\xbc')
 
     def test_encode(self):
+        for content_encoding in ["aesgcm", "aes128gcm"]:
+            recv_key = pyelliptic.ECC(curve="prime256v1")
+            subscription_info = self._gen_subscription_info(recv_key)
+            data = "Mary had a little lamb, with some nice mint jelly"
+            push = WebPusher(subscription_info)
+            encoded = push.encode(data, content_encoding=content_encoding)
+            keyid = base64.urlsafe_b64encode(recv_key.get_pubkey()[1:])
+            http_ece.keys[keyid] = recv_key
+            http_ece.labels[keyid] = 'P-256'
+            # Convert these b64 strings into their raw, binary form.
+            raw_salt = None
+            if 'salt' in encoded:
+                raw_salt = base64.urlsafe_b64decode(
+                    push._repad(encoded['salt']))
+            raw_dh = base64.urlsafe_b64decode(
+                push._repad(encoded['crypto_key']))
+            raw_auth = base64.urlsafe_b64decode(
+                push._repad(subscription_info['keys']['auth']))
+
+            decoded = http_ece.decrypt(
+                encoded['body'],
+                salt=raw_salt,
+                dh=raw_dh,
+                keyid=keyid,
+                authSecret=raw_auth,
+                version=content_encoding
+                )
+            eq_(decoded.decode('utf8'), data)
+
+    def test_bad_content_encoding(self):
         recv_key = pyelliptic.ECC(curve="prime256v1")
         subscription_info = self._gen_subscription_info(recv_key)
         data = "Mary had a little lamb, with some nice mint jelly"
         push = WebPusher(subscription_info)
-        encoded = push.encode(data)
-
-        keyid = base64.urlsafe_b64encode(recv_key.get_pubkey()[1:])
-
-        http_ece.keys[keyid] = recv_key
-        http_ece.labels[keyid] = 'P-256'
-
-        # Convert these b64 strings into their raw, binary form.
-        raw_salt = base64.urlsafe_b64decode(push._repad(encoded['salt']))
-        raw_dh = base64.urlsafe_b64decode(push._repad(encoded['crypto_key']))
-        raw_auth = base64.urlsafe_b64decode(
-            push._repad(subscription_info['keys']['auth']))
-
-        decoded = http_ece.decrypt(
-            encoded['body'],
-            salt=raw_salt,
-            dh=raw_dh,
-            keyid=keyid,
-            authSecret=raw_auth,
-            )
-
-        eq_(decoded.decode('utf8'), data)
+        self.assertRaises(WebPushException,
+                          push.encode,
+                          data,
+                          content_encoding="aesgcm128")
 
     @patch("requests.post")
     def test_send(self, mock_post):

setup.py

@@ -3,7 +3,7 @@
 
 from setuptools import find_packages, setup
 
-__version__ = "0.6.3"
+__version__ = "0.7.0"
 
 
 def read_from(file):