Support custom encoding for basic auth credentials

This introduces BasicAuthEx namedtuple which acts as like as BasicAuth
one with single exception as it handles encoding as third argument.

RFC2617, section 2 (HTTP Authentication) defines basic-credentials:

    basic-credentials = base64-user-pass
    base64-user-pass  = <base64 encoding of user-pass,
                         except not limited to 76 char/line>
    user-pass         = userid ":" password
    userid            = *<TEXT excluding ":">
    password          = *TEXT

RFC 2616, section 2.1 defines TEXT to have ISO-8859-1 encoding
(aka latin1):

    The TEXT rule is only used for descriptive field contents and values
    that are not intended to be interpreted by the message parser. Words
    of *TEXT MAY contain characters from character sets other than
    ISO-8859-1 only when encoded according to the rules of RFC 2047.

In fact, I know no Basic Auth implementation which respects RFC 2047
for Basic Auth.

However, the truth of the real world is that the most major browsers
are already uses UTF-8 instead of ISO-8859-1 for the credentials as
like as any modern web services which allows non-ASCII login/password.

Also, there is the RFC draft which aims to handle the case when
credentials will optionally get always encoded with UTF-8:
http://tools.ietf.org/html/draft-ietf-httpauth-basicauth-update-01

While we should strictly follow common standards, we also need to handle
real world use cases. This change allows that and makes aiohttp ready
for further Basic Auth scheme standard update.

aiohttp/client.py

@@ -1,6 +1,6 @@
 """HTTP Client for asyncio."""
 
-__all__ = ['request', 'HttpClient', 'BasicAuth']
+__all__ = ['request', 'HttpClient', 'BasicAuth', 'BasicAuthEx']
 
 import asyncio
 import base64
@@ -30,6 +30,8 @@
 HTTPS_PORT = 443
 
 BasicAuth = collections.namedtuple('BasicAuth', ['login', 'password'])
+BasicAuthEx = collections.namedtuple('BasicAuthEx',
+                                     ['login', 'password', 'encoding'])
 
 
 @asyncio.coroutine
@@ -354,17 +356,22 @@ def update_auth(self, auth):
         if auth is None:
             return
 
-        if not isinstance(auth, BasicAuth):
+        if not isinstance(auth, (BasicAuth, BasicAuthEx)):
             warnings.warn(
-                'BasicAuth() tuple is required instead ', DeprecationWarning)
+                'BasicAuth() or BasicAuthEx() tuple is required instead ',
+                DeprecationWarning)
 
-        basic_login, basic_passwd = auth
+        if isinstance(auth, BasicAuthEx):
+            basic_login, basic_passwd, encoding = auth
+        else:
+            basic_login, basic_passwd = auth
+            encoding = 'latin1'
 
         if basic_login is not None and basic_passwd is not None:
             self.headers['AUTHORIZATION'] = 'Basic %s' % (
                 base64.b64encode(
-                    ('%s:%s' % (basic_login, basic_passwd)).encode('latin1'))
-                .strip().decode('latin1'))
+                    ('%s:%s' % (basic_login, basic_passwd)).encode(encoding))
+                .strip().decode(encoding))
         elif basic_login is not None or basic_passwd is not None:
             raise ValueError("HTTP Auth login or password is missing")
 

aiohttp/connector.py

@@ -12,7 +12,7 @@
 
 from .errors import HttpProxyError
 from .errors import ProxyConnectionError
-from .client import ClientRequest, BasicAuth
+from .client import ClientRequest, BasicAuth, BasicAuthEx
 
 
 class Connection(object):
@@ -285,8 +285,10 @@ def __init__(self, proxy, *args, proxy_auth=None, **kwargs):
         self._proxy_auth = proxy_auth
         assert proxy.startswith('http://'), (
             "Only http proxy supported", proxy)
-        assert proxy_auth is None or isinstance(proxy_auth, BasicAuth), (
-            "proxy_auth must be None or BasicAuth() tuple", proxy_auth)
+        assert (proxy_auth is None
+                or isinstance(proxy_auth, (BasicAuth, BasicAuthEx))), \
+            ("proxy_auth must be None, BasicAuth() or BasicAuthEx() tuple",
+             proxy_auth)
 
     @property
     def proxy(self):

tests/test_client.py

@@ -395,6 +395,13 @@ def test_basic_auth(self):
         self.assertIn('AUTHORIZATION', req.headers)
         self.assertEqual('Basic bmtpbToxMjM0', req.headers['AUTHORIZATION'])
 
+    def test_basic_auth_utf8(self):
+        req = ClientRequest('get', 'http://python.org',
+                            auth=aiohttp.BasicAuthEx('nkim', 'секрет', 'utf-8'))
+        self.assertIn('AUTHORIZATION', req.headers)
+        self.assertEqual('Basic bmtpbTrRgdC10LrRgNC10YI=',
+                         req.headers['AUTHORIZATION'])
+
     def test_basic_auth_tuple_deprecated(self):
         req = ClientRequest('get', 'http://python.org', auth=('nkim', '1234'))
         self.assertIn('AUTHORIZATION', req.headers)

tests/test_connector.py

@@ -426,6 +426,14 @@ def test_auth(self, ClientRequestMock):
             auth=aiohttp.BasicAuth('user', 'pass'),
             loop=unittest.mock.ANY, headers=unittest.mock.ANY)
 
+    @unittest.mock.patch('aiohttp.connector.ClientRequest')
+    def test_auth_utf8(self, ClientRequestMock):
+        proxy_req = ClientRequest(
+            'GET', 'http://proxy.example.com',
+            auth=aiohttp.BasicAuthEx('юзер', 'пасс', 'utf-8'))
+        ClientRequestMock.return_value = proxy_req
+        self.assertIn('AUTHORIZATION', proxy_req.headers)
+
     @unittest.mock.patch('aiohttp.connector.ClientRequest')
     def test_auth_from_url(self, ClientRequestMock):
         proxy_req = ClientRequest('GET', 'http://user:pass@proxy.example.com')