From b4b3d51f33c7623d312f289252dd7bbb8f58bbe6 Mon Sep 17 00:00:00 2001 From: Unrud Date: Thu, 24 Dec 2015 12:37:11 +0100 Subject: [PATCH] Convert paths safely to file system paths With the old implementation on Windows a path like "/c:/file/ignore" got converted to "c:\file" and allowed access to files outside of FOLDER --- radicale/pathutils.py | 37 +++++++++++++++++++++++++++- radicale/storage/filesystem.py | 35 ++++++++++++++------------ radicale/storage/multifilesystem.py | 38 +++++++++++++++++------------ 3 files changed, 77 insertions(+), 33 deletions(-) diff --git a/radicale/pathutils.py b/radicale/pathutils.py index 5a0e0c8..c3e623b 100644 --- a/radicale/pathutils.py +++ b/radicale/pathutils.py @@ -20,8 +20,11 @@ Helper functions for working with paths """ +import os import posixpath +from . import log + def sanitize_path(path): """Make absolute (with leading slash) to prevent access to other data. @@ -34,4 +37,36 @@ def sanitize_path(path): continue new_path = posixpath.join(new_path, part) trailing_slash = "" if new_path.endswith("/") else trailing_slash - return new_path + trailing_slash \ No newline at end of file + return new_path + trailing_slash + + +def is_safe_filesystem_path_component(path): + """Checks if path is a single component of a local filesystem path + and is safe to join""" + if not path: + return False + drive, _ = os.path.splitdrive(path) + if drive: + return False + head, _ = os.path.split(path) + if head: + return False + if path in (os.curdir, os.pardir): + return False + return True + + +def path_to_filesystem(path, base_folder): + """Converts path to a local filesystem path relative to base_folder + in a secure manner or raises ValueError.""" + sane_path = sanitize_path(path).strip("/") + safe_path = base_folder + if not sane_path: + return safe_path + for part in sane_path.split("/"): + if not is_safe_filesystem_path_component(part): + log.LOGGER.debug("Can't translate path safely to filesystem: %s", + path) + raise ValueError("Unsafe path") + safe_path = os.path.join(safe_path, part) + return safe_path \ No newline at end of file diff --git a/radicale/storage/filesystem.py b/radicale/storage/filesystem.py index a45e8eb..b3e06d2 100644 --- a/radicale/storage/filesystem.py +++ b/radicale/storage/filesystem.py @@ -28,7 +28,8 @@ import json import time import sys from contextlib import contextmanager -from .. import config, ical + +from .. import config, ical, pathutils FOLDER = os.path.expanduser(config.get("storage", "filesystem_folder")) @@ -63,41 +64,41 @@ def open(path, mode="r"): class Collection(ical.Collection): """Collection stored in a flat ical file.""" @property - def _path(self): + def _filesystem_path(self): """Absolute path of the file at local ``path``.""" - return os.path.join(FOLDER, self.path.replace("/", os.sep)) + return pathutils.path_to_filesystem(self.path, FOLDER) @property def _props_path(self): """Absolute path of the file storing the collection properties.""" - return self._path + ".props" + return self._filesystem_path + ".props" def _create_dirs(self): """Create folder storing the collection if absent.""" - if not os.path.exists(os.path.dirname(self._path)): - os.makedirs(os.path.dirname(self._path)) + if not os.path.exists(os.path.dirname(self._filesystem_path)): + os.makedirs(os.path.dirname(self._filesystem_path)) def save(self, text): self._create_dirs() - with open(self._path, "w") as fd: + with open(self._filesystem_path, "w") as fd: fd.write(text) def delete(self): - os.remove(self._path) + os.remove(self._filesystem_path) os.remove(self._props_path) @property def text(self): try: - with open(self._path) as fd: + with open(self._filesystem_path) as fd: return fd.read() except IOError: return "" @classmethod def children(cls, path): - abs_path = os.path.join(FOLDER, path.replace("/", os.sep)) - _, directories, files = next(os.walk(abs_path)) + filesystem_path = pathutils.path_to_filesystem(path, FOLDER) + _, directories, files = next(os.walk(filesystem_path)) for filename in directories + files: rel_filename = posixpath.join(path, filename) if cls.is_node(rel_filename) or cls.is_leaf(rel_filename): @@ -105,17 +106,19 @@ class Collection(ical.Collection): @classmethod def is_node(cls, path): - abs_path = os.path.join(FOLDER, path.replace("/", os.sep)) - return os.path.isdir(abs_path) + filesystem_path = pathutils.path_to_filesystem(path, FOLDER) + return os.path.isdir(filesystem_path) @classmethod def is_leaf(cls, path): - abs_path = os.path.join(FOLDER, path.replace("/", os.sep)) - return os.path.isfile(abs_path) and not abs_path.endswith(".props") + filesystem_path = pathutils.path_to_filesystem(path, FOLDER) + return (os.path.isfile(filesystem_path) and not + filesystem_path.endswith(".props")) @property def last_modified(self): - modification_time = time.gmtime(os.path.getmtime(self._path)) + modification_time = \ + time.gmtime(os.path.getmtime(self._filesystem_path)) return time.strftime("%a, %d %b %Y %H:%M:%S +0000", modification_time) @property diff --git a/radicale/storage/multifilesystem.py b/radicale/storage/multifilesystem.py index 30f8c2d..fe5637d 100644 --- a/radicale/storage/multifilesystem.py +++ b/radicale/storage/multifilesystem.py @@ -30,13 +30,14 @@ import sys from . import filesystem from .. import ical from .. import log +from .. import pathutils class Collection(filesystem.Collection): """Collection stored in several files per calendar.""" def _create_dirs(self): - if not os.path.exists(self._path): - os.makedirs(self._path) + if not os.path.exists(self._filesystem_path): + os.makedirs(self._filesystem_path) @property def headers(self): @@ -52,17 +53,18 @@ class Collection(filesystem.Collection): name = ( component.name if sys.version_info[0] >= 3 else component.name.encode(filesystem.FILESYSTEM_ENCODING)) - path = os.path.join(self._path, name) - with filesystem.open(path, "w") as fd: + filesystem_path = os.path.join(self._filesystem_path, name) + with filesystem.open(filesystem_path, "w") as fd: fd.write(text) def delete(self): - shutil.rmtree(self._path) + shutil.rmtree(self._filesystem_path) os.remove(self._props_path) def remove(self, name): - if os.path.exists(os.path.join(self._path, name)): - os.remove(os.path.join(self._path, name)) + filesystem_path = os.path.join(self._filesystem_path, name) + if os.path.exists(filesystem_path): + os.remove(filesystem_path) @property def text(self): @@ -70,14 +72,14 @@ class Collection(filesystem.Collection): ical.Timezone, ical.Event, ical.Todo, ical.Journal, ical.Card) items = set() try: - filenames = os.listdir(self._path) + filenames = os.listdir(self._filesystem_path) except (OSError, IOError) as e: log.LOGGER.info('Error while reading collection %r: %r' - % (self._path, e)) + % (self._filesystem_path, e)) return "" for filename in filenames: - path = os.path.join(self._path, filename) + path = os.path.join(self._filesystem_path, filename) try: with filesystem.open(path) as fd: items.update(self._parse(fd.read(), components)) @@ -90,17 +92,21 @@ class Collection(filesystem.Collection): @classmethod def is_node(cls, path): - path = os.path.join(filesystem.FOLDER, path.replace("/", os.sep)) - return os.path.isdir(path) and not os.path.exists(path + ".props") + filesystem_path = pathutils.path_to_filesystem(path, + filesystem.FOLDER) + return (os.path.isdir(filesystem_path) and + not os.path.exists(filesystem_path + ".props")) @classmethod def is_leaf(cls, path): - path = os.path.join(filesystem.FOLDER, path.replace("/", os.sep)) - return os.path.isdir(path) and os.path.exists(path + ".props") + filesystem_path = pathutils.path_to_filesystem(path, + filesystem.FOLDER) + return (os.path.isdir(filesystem_path) and + os.path.exists(path + ".props")) @property def last_modified(self): last = max([ - os.path.getmtime(os.path.join(self._path, filename)) - for filename in os.listdir(self._path)] or [0]) + os.path.getmtime(os.path.join(self._filesystem_path, filename)) + for filename in os.listdir(self._filesystem_path)] or [0]) return time.strftime("%a, %d %b %Y %H:%M:%S +0000", time.gmtime(last))