Must staple: check for OCSP support (#9226)

* Must staple: check for OCSP support

* Expand error message

* s/Must Staple/Must-Staple

* Broaden the term webserver

* Improve error message

certbot/CHANGELOG.md

@@ -13,6 +13,10 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 * Dropped 32 bit support for the Windows beta installer
 * Windows beta installer is now distributed as "certbot-beta-installer-win_amd64.exe".
   Users of the Windows beta should uninstall the old version before running this.
+* Added a check whether OCSP stapling is supported by the installer when requesting a
+  certificate with the `run` subcommand in combination with the `--must-staple` option.
+  If the installer does not support OCSP and the `--must-staple` option is used, Certbot
+  will raise an error and quit.
 
 ### Fixed
 

certbot/certbot/_internal/main.py

@@ -1394,6 +1394,20 @@ def run(config: configuration.NamespaceConfig,
     except errors.PluginSelectionError as e:
         return str(e)
 
+    if config.must_staple and installer and "staple-ocsp" not in installer.supported_enhancements():
+        raise errors.NotSupportedError(
+            "Must-Staple extension requested, but OCSP stapling is not supported by the selected "
+            f"installer ({config.installer})\n\n"
+            "You can either:\n"
+            " * remove the --must-staple option from the command line and obtain a certificate "
+            "without the Must-Staple extension, or;\n"
+            " * use the `certonly` subcommand and manually install the certificate into the  "
+            "intended service (e.g. webserver). You must also then manually enable OCSP stapling, "
+            "as it is required for certificates with the Must-Staple extension to "
+            "function properly.\n"
+            " * choose a different installer plugin (such as --nginx or --apache), if possible."
+        )
+
     # Preflight check for enhancement support by the selected installer
     if not enhancements.are_supported(config, installer):
         raise errors.NotSupportedError("One ore more of the requested enhancements "

certbot/certbot/configuration.py

@@ -120,7 +120,7 @@ class NamespaceConfig:
 
     @property
     def must_staple(self) -> bool:
-        """Adds the OCSP Must Staple extension to the certificate.
+        """Adds the OCSP Must-Staple extension to the certificate.
 
         Autoconfigures OCSP Stapling for supported setups
         (Apache version >= 2.3.3 ).

certbot/certbot/crypto_util.py

@@ -143,7 +143,7 @@ def generate_csr(privkey: util.Key, names: Union[List[str], Set[str]], path: str
     :type privkey: :class:`certbot.util.Key`
     :param set names: `str` names to include in the CSR
     :param str path: Certificate save directory.
-    :param bool must_staple: If true, include the TLS Feature extension "OCSP Must Staple"
+    :param bool must_staple: If true, include the TLS Feature extension "OCSP Must-Staple"
     :param bool strict_permissions: If true and path exists, an exception is raised if
         the directory doesn't have 0755 permissions or isn't owned by the current user.
 

certbot/tests/main_test.py

@@ -197,6 +197,15 @@ class RunTest(test_util.ConfigTestCase):
         # The final success message shouldn't be shown
         self.mock_success_installation.assert_not_called()
 
+    @mock.patch('certbot._internal.main.plug_sel.choose_configurator_plugins')
+    def test_run_must_staple_not_supported(self, mock_choose):
+        mock_choose.return_value = (null.Installer(self.config, "null"), None)
+        plugins = disco.PluginsRegistry.find_all()
+        self.config.must_staple = True
+        self.assertRaises(errors.NotSupportedError,
+                          main.run,
+                          self.config, plugins)
+
 class CertonlyTest(unittest.TestCase):
     """Tests for certbot._internal.main.certonly."""