Image Sealing with composefs
Composefs achieves whole-filesystem integrity verification through image sealing: a single cryptographic digest authenticates an entire filesystem, covering both file contents and metadata (directory structure, permissions, ownership, symlinks, and xattrs). Background: the problem composefs solves fs-verity can verify the contents of individual files, but it cannot verify filesystem metadata: directory structure, permissions, ownership, symlink targets, or xattrs. dm-verity can verify entire block devices, but requires a fixed partition layout and prevents content deduplication across images. ...