From 8a15bd7927e2b8956bb1f4d062423e471e473ccf Mon Sep 17 00:00:00 2001
From: Alex Zorin <alex@zorin.id.au>
Date: Thu, 21 May 2020 22:58:40 +1000
Subject: [PATCH 1/2] renewal: disregard acme-v01 in renewal configs

Fixes #7979
---
 certbot/certbot/_internal/constants.py |  2 ++
 certbot/certbot/_internal/renewal.py   | 17 +++++++++++++++--
 certbot/tests/renewal_test.py          |  8 ++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/certbot/certbot/_internal/constants.py b/certbot/certbot/_internal/constants.py
index 9a2220e0b..af6531fe8 100644
--- a/certbot/certbot/_internal/constants.py
+++ b/certbot/certbot/_internal/constants.py
@@ -120,6 +120,8 @@ CLI_DEFAULTS = dict(
 )
 STAGING_URI = "https://acme-staging-v02.api.letsencrypt.org/directory"
 
+V1_URI = "https://acme-v01.api.letsencrypt.org/directory"
+
 # The set of reasons for revoking a certificate is defined in RFC 5280 in
 # section 5.3.1. The reasons that users are allowed to submit are restricted to
 # those accepted by the ACME server implementation. They are listed in
diff --git a/certbot/certbot/_internal/renewal.py b/certbot/certbot/_internal/renewal.py
index fd23b0d18..47244052a 100644
--- a/certbot/certbot/_internal/renewal.py
+++ b/certbot/certbot/_internal/renewal.py
@@ -19,6 +19,7 @@ from certbot import errors
 from certbot import interfaces
 from certbot import util
 from certbot._internal import cli
+from certbot._internal import constants
 from certbot._internal import hooks
 from certbot._internal import storage
 from certbot._internal import updater
@@ -243,16 +244,28 @@ def _restore_int(name, value):
         raise errors.Error("Expected a numeric value for {0}".format(name))
 
 
-def _restore_str(unused_name, value):
+def _restore_str(name, value):
     """Restores a string key-value pair from a renewal config file.
 
-    :param str unused_name: option name
+    :param str name: option name
     :param str value: option value
 
     :returns: converted option value to be stored in the runtime config
     :rtype: str or None
 
     """
+    # Previous to v0.5.0, Certbot always stored the `server` URL in the renewal config,
+    # resulting in configs which explicitly use the deprecated ACMEv1 URL, today
+    # preventing an automatic transition to the default modern ACME URL.
+    # (https://github.com/certbot/certbot/issues/7978#issuecomment-625442870)
+    # As a mitigation, this function reinterprets the value of the `server` parameter if
+    # necessary, replacing the ACMEv1 URL with the default ACME URL. It is still possible
+    # to override this choice with the explicit `--server` CLI flag.
+    if name == "server" and value == constants.V1_URI:
+        logger.info("Using server %s instead of legacy %s",
+                    constants.CLI_DEFAULTS["server"], value)
+        return constants.CLI_DEFAULTS["server"]
+
     return None if value == "None" else value
 
 
diff --git a/certbot/tests/renewal_test.py b/certbot/tests/renewal_test.py
index 1fc54b42e..83796cd4f 100644
--- a/certbot/tests/renewal_test.py
+++ b/certbot/tests/renewal_test.py
@@ -110,6 +110,14 @@ class RestoreRequiredConfigElementsTest(test_util.ConfigTestCase):
         self.assertRaises(
             errors.Error, self._call, self.config, renewalparams)
 
+    @mock.patch('certbot._internal.renewal.cli.set_by_cli')
+    def test_ancient_server_renewal_conf(self, mock_set_by_cli):
+        from certbot._internal import constants
+        self.config.server = None
+        mock_set_by_cli.return_value = False
+        self._call(self.config, {'server': constants.V1_URI})
+        self.assertEqual(self.config.server, constants.CLI_DEFAULTS['server'])
+
 
 if __name__ == "__main__":
     unittest.main()  # pragma: no cover

From bebcad0588c50e671bd2f53074c38b28ac8a4917 Mon Sep 17 00:00:00 2001
From: Erica Portnoy <ebportnoy@gmail.com>
Date: Thu, 4 Jun 2020 15:57:34 -0700
Subject: [PATCH 2/2] update changelog

---
 certbot/CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/certbot/CHANGELOG.md b/certbot/CHANGELOG.md
index b7a71ff9f..e119b66b1 100644
--- a/certbot/CHANGELOG.md
+++ b/certbot/CHANGELOG.md
@@ -11,6 +11,8 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 ### Changed
 
 * Allow session tickets to be disabled in Apache when mod_ssl is statically linked.
+* Read acmev1 Let's Encrypt server URL from renewal config as acmev2 URL to prepare
+  for impending acmev1 deprecation.
 
 ### Fixed