Entry paths

safe_components: checking an entry’s path before extracting it, so an archive cannot write outside the directory it is extracted into.

Source: runtime/archive/path.pep

safe_components

safe_components(path: String): String[]?

Splits the path of an archive entry into its components, or gives none when extracting it could write outside the target directory (“zip slip”): an absolute path, a .. component, a \ or a : (which Windows would read as a separator or a drive letter). Empty and . components are left out, so a//./b/ gives a and b.

TarReader.extract checks every entry with it, and so does the zip package; a reader of another archive format should too.

Parameters

• path — the entry’s path as stored, with / between components

Returns

• the components to join onto the target directory, or none for an unsafe path

Example

import archive;

assert(archive.safe_components("docs/./readme.md").value().count == 2, "safe");
assert(archive.safe_components("../etc/passwd").is_empty(), "climbs out");
assert(archive.safe_components("C:/Windows").is_empty(), "a drive");