Remove metadata from ZIP archives

ZIP archive and member metadata

A ZIP can carry archive and entry comments, names, paths, timestamps and system attributes. Each contained file has its own content and possible metadata. Read the archive findings and member manifest separately; clearing the outer container does not establish the privacy of every image, document or unfamiliar file inside.

• Archive/entry comments, names/paths and modification times
• Extra fields, host and permission attributes
• Entries, nesting, encryption and integrity records

ZIP metadata changes and entry renaming

The supported path processes assessed archive metadata and separately assesses supported members. Sensitive entry names can be renamed, while comments, times or attributes receive reported transformations. Review the resulting paths and each member's disposition. An unsupported or unassessed file cannot receive a clean-content claim from the outer archive's result.

Retained ZIP structure and member content

The assessed regular-file and directory structure retains entry integrity, with supported members governed by their own processing results. An unsupported member's bytes can be preserved with an explicit status. That preservation cannot confer an overall verified clean result. Check every member before the authorised person approves the disclosure pack.

• Assessed regular-file and directory structure, with entry integrity checked.
• Supported member content governed by that member's processing result.
• Unsupported member bytes can remain with an explicit status; this does not establish an overall verified clean result.

ZIP format and member limits

The path covers single-volume, non-ZIP64 archives with unencrypted Store or Deflate entries and portable ASCII or UTF-8 regular-file or directory paths. Multipart archives, symlinks, invalid or colliding paths and unsupported compression are rejected. Entry, expansion and nesting policies are bounded, and unresolved member content cannot inherit archive clearance.

• Only single-volume, non-ZIP64 archives with unencrypted Store or Deflate entries are assessed.
• Paths must be portable ASCII or UTF-8 and refer to regular files or directories.
• Multipart or encrypted archives, symlinks, unsafe or colliding paths and unsupported compression are rejected.
• Entry count, expansion, compression-ratio and nesting policies are bounded.
• Unsupported, unassessed or failed members prevent authoritative evidence for all contained files; archive clearance cannot establish their content is clean.