[feature] authentication classes and tests

4 files changed, 226 insertions, 11 deletions

diff --git a/src/leap/bitmask/core/_web.py b/src/leap/bitmask/core/_web.py
index 1cbba196..c0c041ee 100644
--- a/src/leap/bitmask/core/_web.py
+++ b/src/leap/bitmask/core/_web.py
@@ -23,14 +23,18 @@ import json
 import os
 import pkg_resources
 
-from twisted.internet import reactor
 from twisted.application import service
 
 from twisted.internet import endpoints
-from twisted.web.resource import Resource
+from twisted.cred import portal, checkers, credentials, error as credError
+from twisted.internet import reactor, defer
+from twisted.logger import Logger
+from twisted.web.guard import HTTPAuthSessionWrapper, BasicCredentialFactory
+from twisted.web.resource import IResource, Resource
 from twisted.web.server import Site, NOT_DONE_YET
 from twisted.web.static import File
-from twisted.logger import Logger
+
+from zope.interface import implementer
 
 from leap.bitmask.util import here
 from leap.bitmask.core.dispatcher import CommandDispatcher
@@ -49,6 +53,90 @@ except Exception:
 log = Logger()
 
 
+class TokenCredentialFactory(BasicCredentialFactory):
+    scheme = 'token'
+
+
+@implementer(checkers.ICredentialsChecker)
+class TokenDictChecker:
+
+    credentialInterfaces = (credentials.IUsernamePassword,
+                            credentials.IUsernameHashedPassword)
+
+    def __init__(self, tokens):
+        "tokens: a dict-like object mapping usernames to session-tokens"
+        self.tokens = tokens 
+
+    def requestAvatarId(self, credentials):
+        username = credentials.username
+        if username in self.tokens:
+            if credentials.checkPassword(self.tokens[username]):
+                return defer.succeed(username)
+            else:
+                return defer.fail(
+                    credError.UnauthorizedLogin("Bad session token"))
+        else:
+            return defer.fail(
+                credError.UnauthorizedLogin("No such user"))
+
+
+@implementer(portal.IRealm)
+class HttpPasswordRealm(object):
+
+    def __init__(self, resource):
+        self.resource = resource
+
+    def requestAvatar(self, user, mind, *interfaces):
+        if IResource in interfaces:
+            # the resource is passed on regardless of user
+            return (IResource, self.resource, lambda: None)
+        raise NotImplementedError()
+
+
+@implementer(IResource)
+class WhitelistHTTPAuthSessionWrapper(HTTPAuthSessionWrapper):
+
+    """
+    Wrap a portal, enforcing supported header-based authentication schemes.
+    It doesn't apply the enforcement to routes included in a whitelist.
+    """
+
+    # TODO extend this to inspect the data -- so that we pass a tuple
+    # with the action
+
+    whitelist = (None,)
+
+    def __init__(self, *args, **kw):
+        self.whitelist = kw.pop('whitelist', tuple())
+        super(WhitelistHTTPAuthSessionWrapper, self).__init__(
+            *args, **kw)
+
+    def getChildWithDefault(self, path, request):
+        if request.path in self.whitelist:
+            return self
+        return HTTPAuthSessionWrapper.getChildWithDefault(self, path, request)
+
+    def render(self, request):
+        if request.path in self.whitelist:
+            _res = self._portal.realm.resource
+            return _res.render(request)
+        return HTTPAuthSessionWrapper.render(self, request)
+
+
+
+def protectedResourceFactory(resource, passwords, whitelist):
+    realm = HttpPasswordRealm(resource)
+    # TODO this should have the per-site tokens.
+    # can put it inside the API Resource object.
+    checker = PasswordDictChecker(passwords)
+    resource_portal = portal.Portal(realm, [checker])
+    credentialFactory = TokenCredentialFactory('localhost')
+    protected_resource = WhitelistHTTPAuthSessionWrapper(
+        resource_portal, [credentialFactory],
+        whitelist=whitelist)
+    return protected_resource
+
+
 class HTTPDispatcherService(service.Service):
 
     """
@@ -58,11 +146,16 @@ class HTTPDispatcherService(service.Service):
 
     If the package ``leap.bitmask_js`` is found in the import path, we'll serve
     the whole JS UI in the root resource too (under the ``public`` path).
-    
+
     If that package cannot be found, we'll serve just the javascript wrapper
     around the REST API.
     """
 
+    API_WHITELIST = (
+        '/API/bonafide/user',
+    )
+
+
     def __init__(self, core, port=7070, debug=False, onion=False):
         self._core = core
         self.port = port
@@ -71,6 +164,7 @@ class HTTPDispatcherService(service.Service):
         self.uri = ''
 
     def startService(self):
+        # TODO refactor this, too long----------------------------------------
         if HAS_WEB_UI:
             webdir = os.path.abspath(
                 pkg_resources.resource_filename('leap.bitmask_js', 'public'))
@@ -83,18 +177,27 @@ class HTTPDispatcherService(service.Service):
                 here(), '..', '..', '..',
                 'ui', 'app', 'lib', 'bitmask.js')
             jsapi = File(os.path.abspath(jspath))
+
         root = File(webdir)
 
+        # TODO move this to the tests...
+        DUMMY_PASS = {'user1': 'pass'}
+
         api = Api(CommandDispatcher(self._core))
-        root.putChild(u'API', api)
+        protected_api = protectedResourceFactory(
+            api, DUMMY_PASS, self.API_WHITELIST)
+        root.putChild(u'API', protected_api)
+
+        if not HAS_WEB_UI:
+            root.putChild('bitmask.js', jsapi)
 
         # TODO --- pass requestFactory for header authentication
+        # so that we remove the setting of the cookie.
+
+        # http://www.tsheffler.com/blog/2011/09/22/twisted-learning-about-cred-and-basicdigest-authentication/#Digest_Authentication
         factory = Site(root)
         self.site = factory
 
-        if not HAS_WEB_UI:
-            root.putChild('bitmask.js', jsapi)
-
         if self.onion:
             try:
                 import txtorcon
@@ -102,13 +205,13 @@ class HTTPDispatcherService(service.Service):
                 log.error('onion is enabled, but could not find txtorcon')
                 return
             self._start_onion_service(factory)
-
         else:
             interface = '127.0.0.1'
             endpoint = endpoints.TCP4ServerEndpoint(
                 reactor, self.port, interface=interface)
             self.uri = 'https://%s:%s' % (interface, self.port)
             endpoint.listen(factory)
+
         # TODO this should be set in a callback to the listen call
         self.running = True
 
diff --git a/src/leap/bitmask/core/dispatcher.py b/src/leap/bitmask/core/dispatcher.py
index 11a319fc..59003906 100644
--- a/src/leap/bitmask/core/dispatcher.py
+++ b/src/leap/bitmask/core/dispatcher.py
@@ -43,6 +43,7 @@ class SubCommand(object):
     __metaclass__ = APICommand
 
     def dispatch(self, service, *parts, **kw):
+        subcmd = ''
         try:
             subcmd = parts[1]
             _method = getattr(self, 'do_' + subcmd.upper(), None)
@@ -402,7 +403,7 @@ class CommandDispatcher(object):
         return d
 
     def do_WEBUI(self, *parts):
-        subcmd = parts[1]
+        subcmd = parts[1] if parts and len(parts) > 1 else None
         dispatch = self.subcommand_webui.dispatch
 
         if subcmd == 'enable':
diff --git a/src/leap/bitmask/core/service.py b/src/leap/bitmask/core/service.py
index 9fde7889..cba6f8d9 100644
--- a/src/leap/bitmask/core/service.py
+++ b/src/leap/bitmask/core/service.py
@@ -51,6 +51,12 @@ else:
 
 class BitmaskBackend(configurable.ConfigurableService):
 
+    """
+    The Bitmask Core Backend Service.
+    Here is where the multiple service tree gets composed.
+    This is passed to the command dispatcher.
+    """
+
     def __init__(self, basedir=configurable.DEFAULT_BASEDIR):
 
         configurable.ConfigurableService.__init__(self, basedir)
@@ -217,7 +223,7 @@ class BitmaskBackend(configurable.ConfigurableService):
 class BackendCommands(object):
 
     """
-    General commands for the BitmaskBackend Core Service.
+    General Commands for the BitmaskBackend Core Service.
     """
 
     def __init__(self, core):
diff --git a/tests/unit/core/test_web_api.py b/tests/unit/core/test_web_api.py
new file mode 100644
index 00000000..f440417f
--- /dev/null
+++ b/tests/unit/core/test_web_api.py
@@ -0,0 +1,105 @@
+import base64
+
+from twisted.cred import portal
+from twisted.trial import unittest
+from twisted.web.test.test_web import DummyRequest
+from twisted.web import resource
+
+from leap.bitmask.core import _web
+
+
+def b64encode(s):
+    return base64.b64encode(s).strip()
+
+
+class APIMixin:
+    """
+    L{TestCase} mixin class which defines a number of tests for
+    L{basic.BasicCredentialFactory}.  Because this mixin defines C{setUp}, it
+    must be inherited before L{TestCase}.
+    """
+    def setUp(self):
+        self.request = self.makeRequest()
+
+        api = AuthTestResource()
+        self.realm = _web.HttpPasswordRealm(api)
+        tokens = {'testuser': 'token'}
+        checker = _web.TokenDictChecker(tokens)
+        self.portal = portal.Portal(self.realm, [checker])
+
+    def makeRequest(self, method=b'GET', clientAddress=None):
+        """
+        Create a request object to be passed to
+        TokenCredentialFactory.decode along with a response value.
+        Override this in a subclass.
+        """
+        raise NotImplementedError("%r did not implement makeRequest" % (
+                                  self.__class__,))
+
+
+class WhitelistedResourceTests(APIMixin, unittest.TestCase):
+
+    def makeRequest(self, method=b'GET', clientAddress=None, path='/'):
+        """
+        Create a L{DummyRequest} (change me to create a
+        L{twisted.web.http.Request} instead).
+        """
+        request = DummyRequest(b'/')
+        request.method = method
+        request.client = clientAddress
+        request.path = path
+        return request
+
+    def test_render_returns_unauthorized_by_default(self):
+        """
+        By default, a Whitelisted resource renders with a 401 response code and
+        a I{WWW-Authenticate} header and puts a simple unauthorized message
+        into the response body.
+        """
+        protected = _web.WhitelistHTTPAuthSessionWrapper(
+            self.portal,
+            [_web.TokenCredentialFactory('localhost')])
+        request = self.makeRequest(method='POST', path='/')
+        request.render(protected)
+        assert request.responseCode == 401
+
+        auth_header = request.responseHeaders.getRawHeaders(
+            b'www-authenticate')
+        assert auth_header == [b'token realm="localhost"']
+        assert b'Unauthorized' == b''.join(request.written)
+
+    def test_whitelisted_resource_does_render(self):
+        protected = _web.WhitelistHTTPAuthSessionWrapper(
+            self.portal,
+            [_web.TokenCredentialFactory('localhost')],
+            whitelist=['/whitelisted'])
+        request = self.makeRequest(method='GET', path='/whitelisted')
+        request.render(protected)
+        assert b'dummyGET' == b''.join(request.written)
+
+    def test_good_token_authenticates(self):
+        protected = _web.WhitelistHTTPAuthSessionWrapper(
+            self.portal,
+            [_web.TokenCredentialFactory('localhost')],
+            whitelist=[])
+        request = self.makeRequest(method='GET', path='/')
+        authorization = b64encode(b'testuser:token')
+        request.requestHeaders.addRawHeader(b'authorization',
+                                            b'Token ' + authorization)
+        request.render(protected)
+        assert b'dummyGET' == b''.join(request.written)
+
+    def test_session_does_not_use_cookies(self):
+        # TODO
+        pass
+
+
+class AuthTestResource(resource.Resource):
+
+    isLeaf = True
+
+    def render_GET(self, request):
+        return "dummyGET"
+
+    def render_POST(self, request):
+        return "dummyPOST"