Allow 0.0.0.0 for api interface

For a host to be able to access the daemon running inside a docker
container the damon needs to be listening to 0.0.0.0

- move the API_INTERFACE setting to the adjustablesettings
- check the port matches as well as the interface

lbrynet/conf.py

@@ -170,7 +170,12 @@ ENVIRONMENT = Env(
     #
     # TODO: writing json on the cmd line is a pain, come up with a nicer
     # parser for this data structure. (maybe MAX_KEY_FEE=USD:25
-    max_key_fee=(json.loads, {'USD': {'amount': 25.0, 'address': ''}})
+    max_key_fee=(json.loads, {'USD': {'amount': 25.0, 'address': ''}}),
+    # Changing this value is not-advised as it could potentially
+    # expose the lbrynet daemon to the outside world which would
+    # give an attacker access to your wallet and you could lose
+    # all of your credits.
+    API_INTERFACE=(str, "localhost"),
 )
 
 
@@ -205,7 +210,6 @@ class ApplicationSettings(Settings):
         self.LOG_FILE_NAME = "lbrynet.log"
         self.LOG_POST_URL = "https://lbry.io/log-upload"        
         self.CRYPTSD_FILE_EXTENSION = ".cryptsd"
-        self.API_INTERFACE = "localhost"
         self.API_ADDRESS = "lbryapi"
         self.ICON_PATH = "icons" if platform is WINDOWS else "app.icns"
         self.APP_NAME = "LBRY"

lbrynet/lbrynet_daemon/auth/server.py

@@ -1,4 +1,6 @@
 import logging
+import urlparse
+
 from decimal import Decimal
 from zope.interface import implements
 from twisted.web import server, resource
@@ -219,16 +221,37 @@ class AuthJSONRPCServer(AuthorizedBase):
         request.finish()
 
     def _check_headers(self, request):
-        origin = request.getHeader("Origin")
-        referer = request.getHeader("Referer")
-        if origin not in [None, settings.ORIGIN]:
-            log.warning("Attempted api call from %s", origin)
-            return False
-        if referer is not None and not referer.startswith(settings.REFERER):
-            log.warning("Attempted api call from %s", referer)
+        return (
+            self._check_header_source(request, 'Origin') and
+            self._check_header_source(request, 'Referer'))
+
+    def _check_header_source(self, request, header):
+        """Check if the source of the request is allowed based on the header value."""
+        source = request.getHeader(header)
+        if not self._check_source_of_request(source):
+            log.warning("Attempted api call from invalid %s: %s", header, source)
             return False
         return True
 
+    def _check_source_of_request(self, source):
+        if source is None:
+            return True
+        if settings.API_INTERFACE == '0.0.0.0':
+            return True
+        server, port = self.get_server_port(source)
+        return (
+            server == settings.API_INTERFACE and
+            port == settings.api_port)
+
+    def get_server_port(self, origin):
+        parsed = urlparse.urlparse(origin)
+        server_port = parsed.netloc.split(':')
+        assert len(server_port) <= 2
+        if len(server_port) == 2:
+            return server_port[0], int(server_port[1])
+        else:
+            return server_port[0], 80
+
     def _check_function_path(self, function_path):
         if function_path not in self.callable_methods:
             log.warning("Unknown method: %s", function_path)

tests/unit/lbrynet_daemon/auth/test_server.py

@@ -0,0 +1,61 @@
+import mock
+import requests
+from twisted.trial import unittest
+
+from lbrynet import conf
+from lbrynet.lbrynet_daemon.auth import server
+
+
+class AuthJSONRPCServerTest(unittest.TestCase):
+    # TODO: move to using a base class for tests
+    # and add useful general utilities like this
+    # onto it.
+    def setUp(self):
+        self.server = server.AuthJSONRPCServer(False)
+
+    def _set_setting(self, attr, value):
+        original = getattr(conf.settings, attr)
+        setattr(conf.settings, attr, value)
+        self.addCleanup(lambda: setattr(conf.settings, attr, original))
+
+    def test_get_server_port(self):
+        self.assertSequenceEqual(
+            ('example.com', 80), self.server.get_server_port('http://example.com'))
+        self.assertSequenceEqual(
+            ('example.com', 1234), self.server.get_server_port('http://example.com:1234'))
+
+    def test_foreign_origin_is_rejected(self):
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://example.com')
+        self.assertFalse(self.server._check_header_source(request, 'Origin'))
+
+    def test_wrong_port_is_rejected(self):
+        self._set_setting('api_port', 1234)
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://localhost:9999')
+        self.assertFalse(self.server._check_header_source(request, 'Origin'))
+
+    def test_matching_origin_is_allowed(self):
+        self._set_setting('API_INTERFACE', 'example.com')
+        self._set_setting('api_port', 1234)
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://example.com:1234')
+        self.assertTrue(self.server._check_header_source(request, 'Origin'))
+
+    def test_any_origin_is_allowed(self):
+        self._set_setting('API_INTERFACE', '0.0.0.0')
+        self._set_setting('api_port', 80)
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://example.com')
+        self.assertTrue(self.server._check_header_source(request, 'Origin'))
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://another-example.com')
+        self.assertTrue(self.server._check_header_source(request, 'Origin'))
+
+    def test_matching_referer_is_allowed(self):
+        self._set_setting('API_INTERFACE', 'the_api')
+        self._set_setting('api_port', 1111)
+        request = mock.Mock(['getHeader'])
+        request.getHeader = mock.Mock(return_value='http://the_api:1111?settings')
+        self.assertTrue(self.server._check_header_source(request, 'Referer'))
+        request.getHeader.assert_called_with('Referer')