awshare

Publish an artifact, and fetch it back verified.

awshare bundles a directory into a tar.gz plus a small JSON manifest naming its digest, its size and the files inside it. A consumer fetches the manifest first and can decide, before opening anything, whether the archive is the one that was published.

pip install awshare            # stdlib only
pip install "awshare[seal]"    # adds provenance via awseal

awshare publish ./my-adapter --out ./dist --seal
awshare fetch ./dist/my-adapter.awshare.json --dest ./here --key <publisher-key>

It pairs with awseal; it does not replace it

awshare — are these the bytes that were published?   (integrity)
awseal  — who published them?                        (provenance)

A digest cannot answer the second, because whoever produced the bytes also produced the digest. publish --seal seals the directory before archiving, so the seal travels inside the artifact and one download answers both. Unsealed publishes say so on every run rather than letting a clean-looking pass be mistaken for provenance.

Exit codes are three answers, not two

0   verified
1   checked, and it failed      (digest mismatch, wrong publisher, bad seal)
2   could not check at all      (missing archive, unknown manifest version)

Collapsing 1 and 2 is how "I could not check this" becomes "it checked out". This package's own CLI got it wrong first: an artifact from the wrong publisher — definitively judged and definitively rejected — exited 2, the code reserved for not being able to tell.

What it refuses

• Path traversal, in four flavours, because each defeats the previous defence: .. segments, absolute paths (Path("/a") / "/etc/passwd" is /etc/passwd), Windows drive-relative names, and symlinks inside the destination that only escape after resolve().
• Non-regular archive members. A symlink in a tarball passes every check applied to its name and points anywhere once created.
• Unbounded expansion. A small download that expands without limit fills the disk long before anyone reads a log line.
• An empty tree. It would fetch and verify perfectly while containing nothing.
• Contents that disagree with the manifest, even when the digest matches — that is a manifest describing a different set of files to the one it names, which is worse than corruption because every integrity check passes.

Archives normalise uid, gid and mtime, so two builds of identical content produce identical bytes and a content-addressed store does not treat them as different artifacts.

Licence

Apache-2.0.