From ab0b111af0843234143f9d2167200b1df032e4b1 Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Tue, 16 Jan 2024 23:24:25 +0100
Subject: [PATCH] give clean error msg for invalid nonce file, see #7967

this is a fwd port from 1.4-maint. as we don't have nonce files
any more in master, only the generally useful stuff has been ported.

- add Error / ErrorWithTraceback exception classes to RPC layer.
- add hex_to_bin helper
---
 src/borg/helpers/__init__.py    |  2 +-
 src/borg/helpers/parseformat.py | 15 +++++++++++++--
 src/borg/remote.py              |  8 ++++++--
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/borg/helpers/__init__.py b/src/borg/helpers/__init__.py
index 0f4f98e51..82364613d 100644
--- a/src/borg/helpers/__init__.py
+++ b/src/borg/helpers/__init__.py
@@ -25,7 +25,7 @@
 from .fs import HardLinkManager
 from .misc import sysinfo, log_multi, consume
 from .misc import ChunkIteratorFileWrapper, open_item, chunkit, iter_separated, ErrorIgnoringTextIOWrapper
-from .parseformat import bin_to_hex, safe_encode, safe_decode
+from .parseformat import bin_to_hex, hex_to_bin, safe_encode, safe_decode
 from .parseformat import text_to_json, binary_to_json, remove_surrogates, join_cmd
 from .parseformat import eval_escapes, decode_dict, positive_int_validator, interval
 from .parseformat import PathSpec, SortBySpec, ChunkerParams, FilesCacheMode, partial_format, DatetimeWrapper
diff --git a/src/borg/helpers/parseformat.py b/src/borg/helpers/parseformat.py
index e5752d34a..c82769730 100644
--- a/src/borg/helpers/parseformat.py
+++ b/src/borg/helpers/parseformat.py
@@ -1,6 +1,7 @@
 import abc
 import argparse
 import base64
+import binascii
 import hashlib
 import json
 import os
@@ -10,7 +11,6 @@
 import stat
 import uuid
 from typing import Dict, Set, Tuple, ClassVar, Any, TYPE_CHECKING, Literal
-from binascii import hexlify
 from collections import Counter, OrderedDict
 from datetime import datetime, timezone
 from functools import partial
@@ -33,7 +33,18 @@
 
 
 def bin_to_hex(binary):
-    return hexlify(binary).decode("ascii")
+    return binascii.hexlify(binary).decode("ascii")
+
+
+def hex_to_bin(hex, length=None):
+    try:
+        binary = binascii.unhexlify(hex)
+        binary_len = len(binary)
+        if length is not None and binary_len != length:
+            raise ValueError(f"Expected {length} bytes ({2 * length} hex digits), got {binary_len} bytes.")
+    except binascii.Error as e:
+        raise ValueError(str(e)) from None
+    return binary
 
 
 def safe_decode(s, coding="utf-8", errors="surrogateescape"):
diff --git a/src/borg/remote.py b/src/borg/remote.py
index 5d9cb1af9..0aa636220 100644
--- a/src/borg/remote.py
+++ b/src/borg/remote.py
@@ -21,7 +21,7 @@
 from . import __version__
 from .compress import Compressor
 from .constants import *  # NOQA
-from .helpers import Error, IntegrityError
+from .helpers import Error, ErrorWithTraceback, IntegrityError
 from .helpers import bin_to_hex
 from .helpers import get_limited_unpacker
 from .helpers import replace_placeholders
@@ -766,7 +766,11 @@ def handle_error(unpacked):
             error = unpacked["exception_class"]
             args = unpacked["exception_args"]
 
-            if error == "DoesNotExist":
+            if error == "Error":
+                raise Error(args[0])
+            elif error == "ErrorWithTraceback":
+                raise ErrorWithTraceback(args[0])
+            elif error == "DoesNotExist":
                 raise Repository.DoesNotExist(self.location.processed)
             elif error == "AlreadyExists":
                 raise Repository.AlreadyExists(self.location.processed)