diff options
Diffstat (limited to 'cloudinit/ssh_util.py')
| -rw-r--r-- | cloudinit/ssh_util.py | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/cloudinit/ssh_util.py b/cloudinit/ssh_util.py index b8a3c8f7..9ccadf09 100644 --- a/cloudinit/ssh_util.py +++ b/cloudinit/ssh_util.py @@ -321,23 +321,48 @@ def check_create_path(username, filename, strictmodes): home_folder = os.path.dirname(user_pwent.pw_dir) for directory in directories: parent_folder += "/" + directory - if home_folder.startswith(parent_folder): + + # security check, disallow symlinks in the AuthorizedKeysFile path. + if os.path.islink(parent_folder): + LOG.debug( + "Invalid directory. Symlink exists in path: %s", + parent_folder) + return False + + if os.path.isfile(parent_folder): + LOG.debug( + "Invalid directory. File exists in path: %s", + parent_folder) + return False + + if (home_folder.startswith(parent_folder) or + parent_folder == user_pwent.pw_dir): continue - if not os.path.isdir(parent_folder): + if not os.path.exists(parent_folder): # directory does not exist, and permission so far are good: # create the directory, and make it accessible by everyone # but owned by root, as it might be used by many users. with util.SeLinuxGuard(parent_folder): - os.makedirs(parent_folder, mode=0o755, exist_ok=True) - util.chownbyid(parent_folder, root_pwent.pw_uid, - root_pwent.pw_gid) + mode = 0o755 + uid = root_pwent.pw_uid + gid = root_pwent.pw_gid + if parent_folder.startswith(user_pwent.pw_dir): + mode = 0o700 + uid = user_pwent.pw_uid + gid = user_pwent.pw_gid + os.makedirs(parent_folder, mode=mode, exist_ok=True) + util.chownbyid(parent_folder, uid, gid) permissions = check_permissions(username, parent_folder, filename, False, strictmodes) if not permissions: return False + if os.path.islink(filename) or os.path.isdir(filename): + LOG.debug("%s is not a file!", filename) + return False + # check the file if not os.path.exists(filename): # if file does not exist: we need to create it, since the |