From f5cddf0224a5e33b0f69096c0889c2248673ee42 Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Sun, 10 Apr 2022 20:58:59 +0200
Subject: [PATCH] load_key: no key is same as empty key, fixes #6441

when migrating from repokey to keyfile, we just store an empty key into the repo config,
because we do not have a "delete key" RPC api. thus, empty key means "there is no key".

here we fix load_key, so that it does not behave differently for no key and empty key:
in both cases, it just returns an empty value.

additionally, we strip the value we get from the config, so whitespace does not matter.

All callers now check for the repokey not being empty, otherwise RepoKeyNotFoundError
is raised.
---
 src/borg/crypto/key.py        | 12 ++++++++----
 src/borg/crypto/keymanager.py |  9 +++++++--
 src/borg/repository.py        |  2 +-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/borg/crypto/key.py b/src/borg/crypto/key.py
index 9fe2ad9ac..879f85c88 100644
--- a/src/borg/crypto/key.py
+++ b/src/borg/crypto/key.py
@@ -617,11 +617,11 @@ class FlexiKey:
             raise KeyfileNotFoundError(self.repository._location.canonical_path(), get_keys_dir())
         elif self.STORAGE == KeyBlobStorage.REPO:
             loc = self.repository._location.canonical_path()
-            try:
-                self.repository.load_key()
-                return loc
-            except configparser.NoOptionError:
+            key = self.repository.load_key()
+            if not key:
+                # if we got an empty key, it means there is no key.
                 raise RepoKeyNotFoundError(loc) from None
+            return loc
         else:
             raise TypeError('Unsupported borg key storage type')
 
@@ -681,6 +681,10 @@ class FlexiKey:
             # what we get in target is just a repo location, but we already have the repo obj:
             target = self.repository
             key_data = target.load_key()
+            if not key_data:
+                # if we got an empty key, it means there is no key.
+                loc = target._location.canonical_path()
+                raise RepoKeyNotFoundError(loc) from None
             key_data = key_data.decode('utf-8')  # remote repo: msgpack issue #99, getting bytes
         else:
             raise TypeError('Unsupported borg key storage type')
diff --git a/src/borg/crypto/keymanager.py b/src/borg/crypto/keymanager.py
index 32dd39c04..2d41c3022 100644
--- a/src/borg/crypto/keymanager.py
+++ b/src/borg/crypto/keymanager.py
@@ -7,7 +7,7 @@ from hashlib import sha256
 from ..helpers import Manifest, NoManifestError, Error, yes, bin_to_hex, dash_open
 from ..repository import Repository
 
-from .key import KeyfileKey, KeyfileNotFoundError, KeyBlobStorage, identify_key
+from .key import KeyfileKey, KeyfileNotFoundError, RepoKeyNotFoundError, KeyBlobStorage, identify_key
 
 
 class UnencryptedRepo(Error):
@@ -56,7 +56,12 @@ class KeyManager:
                 self.keyblob = ''.join(fd.readlines()[1:])
 
         elif self.keyblob_storage == KeyBlobStorage.REPO:
-            self.keyblob = self.repository.load_key().decode()
+            key_data = self.repository.load_key().decode()
+            if not key_data:
+                # if we got an empty key, it means there is no key.
+                loc = self.repository._location.canonical_path()
+                raise RepoKeyNotFoundError(loc) from None
+            self.keyblob = key_data
 
     def store_keyblob(self, args):
         if self.keyblob_storage == KeyBlobStorage.KEYFILE:
diff --git a/src/borg/repository.py b/src/borg/repository.py
index 59129bec9..50c68a750 100644
--- a/src/borg/repository.py
+++ b/src/borg/repository.py
@@ -343,7 +343,7 @@ class Repository:
         self.save_config(self.path, self.config)
 
     def load_key(self):
-        keydata = self.config.get('repository', 'key')
+        keydata = self.config.get('repository', 'key', fallback='').strip()
         # note: if we return an empty string, it means there is no repo key
         return keydata.encode('utf-8')  # remote repo: msgpack issue #99, returning bytes