Get rid of pretty_bad_protocol monkey-patching

And just implement them in the code directly now. We still set
the `USERNAME` environment variable via encryption.py since there's
not really a logical place for it in pretty_bad_protocol.

Fixes #6807.

securedrop/encryption.py

@@ -13,41 +13,8 @@
 if typing.TYPE_CHECKING:
     from source_user import SourceUser
 
-
-def _monkey_patch_username_in_env() -> None:
-    # To fix https://github.com/freedomofpress/securedrop/issues/78
-    os.environ["USERNAME"] = "www-data"
-
-
-def _monkey_patch_unknown_status_message() -> None:
-    # To fix https://github.com/isislovecruft/python-gnupg/issues/250 with Focal gnupg
-    gnupg._parsers.Verify.TRUST_LEVELS["DECRYPTION_COMPLIANCE_MODE"] = 23
-
-
-def _monkey_patch_delete_handle_status() -> None:
-    # To fix https://github.com/freedomofpress/securedrop/issues/4294
-    def _updated_handle_status(self: gnupg._parsers.DeleteResult, key: str, value: str) -> None:
-        """
-        Parse a status code from the attached GnuPG process.
-        :raises: :exc:`~exceptions.ValueError` if the status message is unknown.
-        """
-        if key in ("DELETE_PROBLEM", "KEY_CONSIDERED"):
-            self.status = self.problem_reason.get(value, "Unknown error: %r" % value)
-        elif key in ("PINENTRY_LAUNCHED"):
-            self.status = key.replace("_", " ").lower()
-        else:
-            raise ValueError("Unknown status message: %r" % key)
-
-    gnupg._parsers.DeleteResult._handle_status = _updated_handle_status
-
-
-def _setup_monkey_patches_for_gnupg() -> None:
-    _monkey_patch_username_in_env()
-    _monkey_patch_unknown_status_message()
-    _monkey_patch_delete_handle_status()
-
-
-_setup_monkey_patches_for_gnupg()
+# To fix https://github.com/freedomofpress/securedrop/issues/78
+os.environ["USERNAME"] = "www-data"
 
 
 class GpgKeyNotFoundError(Exception):

securedrop/pretty_bad_protocol/_parsers.py

@@ -1082,12 +1082,14 @@ def __str__(self):  # type: ignore[no-untyped-def] # noqa
     }
 
     def _handle_status(self, key, value):  # type: ignore[no-untyped-def] # noqa
-        """Parse a status code from the attached GnuPG process.
-
+        """
+        Parse a status code from the attached GnuPG process.
         :raises: :exc:`~exceptions.ValueError` if the status message is unknown.
         """
         if key in ("DELETE_PROBLEM", "KEY_CONSIDERED"):
             self.status = self.problem_reason.get(value, "Unknown error: %r" % value)
+        elif key in ("PINENTRY_LAUNCHED"):
+            self.status = key.replace("_", " ").lower()
         else:
             raise ValueError("Unknown status message: %r" % key)
 
@@ -1487,13 +1489,16 @@ class Verify:
     TRUST_MARGINAL = 2
     TRUST_FULLY = 3
     TRUST_ULTIMATE = 4
+    DECRYPTION_COMPLIANCE_MODE = 23
 
     TRUST_LEVELS = {
         "TRUST_UNDEFINED": TRUST_UNDEFINED,
         "TRUST_NEVER": TRUST_NEVER,
         "TRUST_MARGINAL": TRUST_MARGINAL,
         "TRUST_FULLY": TRUST_FULLY,
         "TRUST_ULTIMATE": TRUST_ULTIMATE,
+        # To fix https://github.com/isislovecruft/python-gnupg/issues/250 with Focal gnupg
+        "DECRYPTION_COMPLIANCE_MODE": DECRYPTION_COMPLIANCE_MODE,
     }
 
     def __init__(self, gpg):  # type: ignore[no-untyped-def] # noqa