feat: Regional twr header in the access token (#546)

Co-authored-by: Elise Shanholtz <eshanholtz@twilio.com>

Author: charliesantos

tests/unit/jwt/test_access_token.py

@@ -54,6 +54,18 @@ def test_empty_grants(self):
         self._validate_claims(decoded_token.payload)
         assert_equal({}, decoded_token.payload['grants'])
 
+    def test_region(self):
+        scat = AccessToken(ACCOUNT_SID, SIGNING_KEY_SID, 'secret', region='foo')
+        token = scat.to_jwt()
+        decoded_token = AccessToken.from_jwt(token, 'secret')
+        assert_equal(decoded_token.headers['twr'], 'foo')
+
+    def test_empty_region(self):
+        scat = AccessToken(ACCOUNT_SID, SIGNING_KEY_SID, 'secret')
+        token = scat.to_jwt()
+        decoded_token = AccessToken.from_jwt(token, 'secret')
+        self.assertRaises(KeyError, lambda: decoded_token.headers['twr'])
+
     def test_nbf(self):
         now = int(time.mktime(datetime.now().timetuple()))
         scat = AccessToken(ACCOUNT_SID, SIGNING_KEY_SID, 'secret', nbf=now)

twilio/jwt/access_token/__init__.py

@@ -21,14 +21,15 @@ def __str__(self):
 class AccessToken(Jwt):
     """Access Token containing one or more AccessTokenGrants used to access Twilio Resources"""
     def __init__(self, account_sid, signing_key_sid, secret, grants=None,
-                 identity=None, nbf=Jwt.GENERATE, ttl=3600, valid_until=None):
+                 identity=None, nbf=Jwt.GENERATE, ttl=3600, valid_until=None, region=None):
         grants = grants or []
         if any(not isinstance(g, AccessTokenGrant) for g in grants):
             raise ValueError('Grants must be instances of AccessTokenGrant.')
 
         self.account_sid = account_sid
         self.signing_key_sid = signing_key_sid
         self.identity = identity
+        self.region = region
         self.grants = grants
         super(AccessToken, self).__init__(
             secret_key=secret,
@@ -47,9 +48,12 @@ def add_grant(self, grant):
         self.grants.append(grant)
 
     def _generate_headers(self):
-        return {
+        headers = {
             'cty': 'twilio-fpa;v=1'
         }
+        if self.region and isinstance(self.region, str):
+            headers['twr'] = self.region
+        return headers
 
     def _generate_payload(self):
         now = int(time.time())