Remove tls-sni in compatibility tests (#6854)

* Reconfigure compatibility tests to use http challenge

* Correct simple test

* Add a fake DNS resolution for HTTP simple_verify

* Debug

* More subtle approach: we monkey patch urllib3 to fake a dns resolution to the target IP, allowing every host header to be preserved.

* Private package

* Relaxed permissions on certbot temp working dir

* Move the fake DNS logic in compatibility test, to avoid degrading the acme coverage

* Fix lint

* Update certbot-compatibility-test/certbot_compatibility_test/configurators/common.py

Co-Authored-By: adferrand <adferrand@users.noreply.github.com>

certbot-compatibility-test/certbot_compatibility_test/configurators/common.py

@@ -23,6 +23,9 @@ def add_parser_arguments(cls, parser):
     def __init__(self, args):
         """Initializes the plugin with the given command line args"""
         self._temp_dir = tempfile.mkdtemp()
+        # tempfile.mkdtemp() creates folders with too restrictive permissions to be accessible
+        # to an Apache worker, leading to HTTP challenge failures. Let's fix that.
+        os.chmod(self._temp_dir, 0o755)
         self.le_config = util.create_le_config(self._temp_dir)
         config_dir = util.extract_configs(args.configs, self._temp_dir)
         self._configs = [

certbot-compatibility-test/certbot_compatibility_test/test_driver.py

@@ -1,12 +1,14 @@
 """Tests Certbot plugins against different server configurations."""
 import argparse
+import contextlib
 import filecmp
 import logging
 import os
 import shutil
 import tempfile
 import time
 import sys
+from urllib3.util import connection
 
 import OpenSSL
 
@@ -64,18 +66,19 @@ def test_authenticator(plugin, config, temp_dir):
                 "Plugin failed to complete %s for %s in %s",
                 type(achalls[i]), achalls[i].domain, config)
             success = False
-        elif isinstance(responses[i], challenges.TLSSNI01Response):
-            verified = responses[i].simple_verify(achalls[i].chall,
-                                                  achalls[i].domain,
-                                                  util.JWK.public_key(),
-                                                  host="127.0.0.1",
-                                                  port=plugin.https_port)
+        elif isinstance(responses[i], challenges.HTTP01Response):
+            # We fake the DNS resolution to ensure that any domain is resolved
+            # to the local HTTP server setup for the compatibility tests
+            with _fake_dns_resolution("127.0.0.1"):
+                verified = responses[i].simple_verify(
+                    achalls[i].chall, achalls[i].domain,
+                    util.JWK.public_key(), port=plugin.http_port)
             if verified:
                 logger.info(
-                    "tls-sni-01 verification for %s succeeded", achalls[i].domain)
+                    "http-01 verification for %s succeeded", achalls[i].domain)
             else:
                 logger.error(
-                    "**** tls-sni-01 verification for %s in %s failed",
+                    "**** http-01 verification for %s in %s failed",
                     achalls[i].domain, config)
                 success = False
 
@@ -102,9 +105,9 @@ def _create_achalls(plugin):
     for domain in names:
         prefs = plugin.get_chall_pref(domain)
         for chall_type in prefs:
-            if chall_type == challenges.TLSSNI01:
-                chall = challenges.TLSSNI01(
-                    token=os.urandom(challenges.TLSSNI01.TOKEN_SIZE))
+            if chall_type == challenges.HTTP01:
+                chall = challenges.HTTP01(
+                    token=os.urandom(challenges.HTTP01.TOKEN_SIZE))
                 challb = acme_util.chall_to_challb(
                     chall, messages.STATUS_PENDING)
                 achall = achallenges.KeyAuthorizationAnnotatedChallenge(
@@ -369,5 +372,21 @@ def main():
         sys.exit(1)
 
 
+@contextlib.contextmanager
+def _fake_dns_resolution(resolved_ip):
+    """Monkey patch urllib3 to make any hostname be resolved to the provided IP"""
+    _original_create_connection = connection.create_connection
+
+    def _patched_create_connection(address, *args, **kwargs):
+        _, port = address
+        return _original_create_connection((resolved_ip, port), *args, **kwargs)
+
+    try:
+        connection.create_connection = _patched_create_connection
+        yield
+    finally:
+        connection.create_connection = _original_create_connection
+
+
 if __name__ == "__main__":
     main()