Add support to OIDC auth

Fix for the `TypeError: Incorrect padding` error
Adding test with "mocked" variables

Persist the new token (refresh token) and add a not-ssl-verification for the refresh token call (i didn't find a way to pass the certificate to OAuth2Session

fixing the refresh-token problem (ssl certificate) and saving returning the new refresh-token

Fix test

fixing  coding style errors

Fixing test update-pep8

Fix test_oidc_with_refresh error

Author: ltamaster

config/kube_config.py

@@ -15,13 +15,17 @@
 import atexit
 import base64
 import datetime
+import json
 import os
 import tempfile
 
 import google.auth
 import google.auth.transport.requests
+import oauthlib.oauth2
 import urllib3
 import yaml
+from requests_oauthlib import OAuth2Session
+from six import PY3
 
 from kubernetes.client import ApiClient, Configuration
 
@@ -169,14 +173,17 @@ def _load_authentication(self):
             1. GCP auth-provider
             2. token_data
             3. token field (point to a token file)
-            4. username/password
+            4. oidc auth-provider
+            5. username/password
         """
         if not self._user:
             return
         if self._load_gcp_token():
             return
         if self._load_user_token():
             return
+        if self._load_oid_token():
+            return
         self._load_user_pass_token()
 
     def _load_gcp_token(self):
@@ -208,6 +215,100 @@ def _refresh_gcp_token(self):
         if self._config_persister:
             self._config_persister(self._config.value)
 
+    def _load_oid_token(self):
+        if 'auth-provider' not in self._user:
+            return
+        provider = self._user['auth-provider']
+
+        if 'name' not in provider or 'config' not in provider:
+            return
+
+        if provider['name'] != 'oidc':
+            return
+
+        parts = provider['config']['id-token'].split('.')
+
+        if len(parts) != 3:  # Not a valid JWT
+            return None
+
+        if PY3:
+            jwt_attributes = json.loads(
+                base64.b64decode(parts[1]).decode('utf-8')
+            )
+        else:
+            jwt_attributes = json.loads(
+                base64.b64decode(parts[1] + "==")
+            )
+
+        expire = jwt_attributes.get('exp')
+
+        if ((expire is not None) and
+            (_is_expired(datetime.datetime.fromtimestamp(expire,
+                                                         tz=UTC)))):
+            self._refresh_oidc(provider)
+
+            if self._config_persister:
+                self._config_persister(self._config.value)
+
+        self.token = "Bearer %s" % provider['config']['id-token']
+
+        return self.token
+
+    def _refresh_oidc(self, provider):
+        ca_cert = tempfile.NamedTemporaryFile(delete=True)
+
+        if PY3:
+            cert = base64.b64decode(
+                provider['config']['idp-certificate-authority-data']
+            ).decode('utf-8')
+        else:
+            cert = base64.b64decode(
+                provider['config']['idp-certificate-authority-data'] + "=="
+            )
+
+        with open(ca_cert.name, 'w') as fh:
+            fh.write(cert)
+
+        config = Configuration()
+        config.ssl_ca_cert = ca_cert.name
+
+        client = ApiClient(configuration=config)
+
+        response = client.request(
+            method="GET",
+            url="%s/.well-known/openid-configuration"
+            % provider['config']['idp-issuer-url']
+        )
+
+        if response.status != 200:
+            return
+
+        response = json.loads(response.data)
+
+        request = OAuth2Session(
+            client_id=provider['config']['client-id'],
+            token=provider['config']['refresh-token'],
+            auto_refresh_kwargs={
+                'client_id': provider['config']['client-id'],
+                'client_secret': provider['config']['client-secret']
+            },
+            auto_refresh_url=response['token_endpoint']
+        )
+
+        try:
+            refresh = request.refresh_token(
+                token_url=response['token_endpoint'],
+                refresh_token=provider['config']['refresh-token'],
+                auth=(provider['config']['client-id'],
+                      provider['config']['client-secret']),
+                verify=ca_cert.name
+            )
+        except oauthlib.oauth2.rfc6749.errors.InvalidClientIdError:
+            return
+
+        provider['config'].value['id-token'] = refresh['id_token']
+        provider['config'].value['refresh-token'] = refresh['refresh_token']
+
     def _load_user_token(self):
         token = FileOrData(
             self._user, 'tokenFile', 'token',

config/kube_config_test.py

@@ -14,11 +14,13 @@
 
 import base64
 import datetime
+import json
 import os
 import shutil
 import tempfile
 import unittest
 
+import mock
 import yaml
 from six import PY3
 
@@ -67,6 +69,17 @@ def _raise_exception(st):
 TEST_CLIENT_CERT_BASE64 = _base64(TEST_CLIENT_CERT)
 
 
+TEST_OIDC_TOKEN = "test-oidc-token"
+TEST_OIDC_INFO = "{\"name\": \"test\"}"
+TEST_OIDC_BASE = _base64(TEST_OIDC_TOKEN) + "." + _base64(TEST_OIDC_INFO)
+TEST_OIDC_LOGIN = TEST_OIDC_BASE + "." + TEST_CLIENT_CERT_BASE64
+TEST_OIDC_TOKEN = "Bearer %s" % TEST_OIDC_LOGIN
+TEST_OIDC_EXP = "{\"name\": \"test\",\"exp\": 536457600}"
+TEST_OIDC_EXP_BASE = _base64(TEST_OIDC_TOKEN) + "." + _base64(TEST_OIDC_EXP)
+TEST_OIDC_EXPIRED_LOGIN = TEST_OIDC_EXP_BASE + "." + TEST_CLIENT_CERT_BASE64
+TEST_OIDC_CA = _base64(TEST_CERTIFICATE_AUTH)
+
+
 class BaseTestCase(unittest.TestCase):
 
     def setUp(self):
@@ -317,6 +330,20 @@ class TestKubeConfigLoader(BaseTestCase):
                     "user": "expired_gcp"
                 }
             },
+            {
+                "name": "oidc",
+                "context": {
+                    "cluster": "default",
+                    "user": "oidc"
+                }
+            },
+            {
+                "name": "expired_oidc",
+                "context": {
+                    "cluster": "default",
+                    "user": "expired_oidc"
+                }
+            },
             {
                 "name": "user_pass",
                 "context": {
@@ -434,6 +461,33 @@ class TestKubeConfigLoader(BaseTestCase):
                     "password": TEST_PASSWORD,  # should be ignored
                 }
             },
+            {
+                "name": "oidc",
+                "user": {
+                    "auth-provider": {
+                        "name": "oidc",
+                        "config": {
+                            "id-token": TEST_OIDC_LOGIN
+                        }
+                    }
+                }
+            },
+            {
+                "name": "expired_oidc",
+                "user": {
+                    "auth-provider": {
+                        "name": "oidc",
+                        "config": {
+                            "client-id": "tectonic-kubectl",
+                            "client-secret": "FAKE_SECRET",
+                            "id-token": TEST_OIDC_EXPIRED_LOGIN,
+                            "idp-certificate-authority-data": TEST_OIDC_CA,
+                            "idp-issuer-url": "https://example.org/identity",
+                            "refresh-token": "lucWJjEhlxZW01cXI3YmVlcYnpxNGhzk"
+                        }
+                    }
+                }
+            },
             {
                 "name": "user_pass",
                 "user": {
@@ -528,6 +582,39 @@ def cred(): return None
         self.assertEqual(BEARER_TOKEN_FORMAT % TEST_ANOTHER_DATA_BASE64,
                          loader.token)
 
+    def test_oidc_no_refresh(self):
+        loader = KubeConfigLoader(
+            config_dict=self.TEST_KUBE_CONFIG,
+            active_context="oidc",
+        )
+        self.assertTrue(loader._load_oid_token())
+        self.assertEqual(TEST_OIDC_TOKEN, loader.token)
+
+    @mock.patch('kubernetes.config.kube_config.OAuth2Session.refresh_token')
+    @mock.patch('kubernetes.config.kube_config.ApiClient.request')
+    def test_oidc_with_refresh(self, mock_ApiClient, mock_OAuth2Session):
+        mock_response = mock.MagicMock()
+        type(mock_response).status = mock.PropertyMock(
+            return_value=200
+        )
+        type(mock_response).data = mock.PropertyMock(
+            return_value=json.dumps({
+                "token_endpoint": "https://example.org/identity/token"
+            })
+        )
+
+        mock_ApiClient.return_value = mock_response
+
+        mock_OAuth2Session.return_value = {"id_token": "abc123",
+                                           "refresh_token": "newtoken123"}
+
+        loader = KubeConfigLoader(
+            config_dict=self.TEST_KUBE_CONFIG,
+            active_context="expired_oidc",
+        )
+        self.assertTrue(loader._load_oid_token())
+        self.assertEqual("Bearer abc123", loader.token)
+
     def test_user_pass(self):
         expected = FakeConfig(host=TEST_HOST, token=TEST_BASIC_TOKEN)
         actual = FakeConfig()