Exact

Exact Union RegExp

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Transaction Science ae4ce533d7 wai: a C2PA Manifest Store bound to a stored WAI1 or WAI2 envelope, and to the receipt that delivered it ... A .wai file can now be a C2PA asset without changing an envelope byte. extensions/c2pa-binding.md registers the record `wai.asset.c2pa`: a C2PA Manifest Store served beside the object at <cid>.c2pa (application/c2pa, C2PA 2.4 §11.4 and §15.5.3.1; an object's response may name it with Link rel="c2pa-manifest", §15.5.3.2), never inside it, so the object's content hash, its receipts and its head proof stay as they were. http-delivery §8.9 gives the location. The store is live provenance's profile (JUMBF layout, claim, EdDSA COSE claim signature, X.509 chain) with three assertions: c2pa.hash.data over every byte of the envelope with no exclusions and an empty pad (§18.5); c2pa.actions.v2 with the source type the signer states; and science.transaction.wai.envelope, which names the envelope's content hash, its capabilities (a WAI2's in table order) and the JWP group receipt it was delivered under, by link hash (also the name of its rcpt/ file), with that receipt's publisher key. The receipt must be in the labelled payload, whose link hash covers its parent. The manifest identifier is derived from the envelope, the receipt and the claim signer's certificate. A verifier checks the claim and chain (live-provenance §11.2 steps 1-6), the assertions, the identifier, the data hash, the content hash and capabilities, the receipt's link hash, signature and publisher, and the envelope's object receipt under it: seventeen reasons, each with its C2PA §15 code where C2PA gives one. The reference is the c2pa_envelope module of wai-rs (feature c2pa_envelope; writer c2pa_envelope::sign); the corpus is live-conformance/c2pa-envelope/ (stores bound to a WAI1 and to a WAI2 of one picture at two sizes, 27 negatives covering every reason), written from fixed seeds by wai_c2pa_envelope_vectors; c2pa_live_verify.py, the second implementation, now also verifies it: 29 vectors agree, 26 of 26 mutated copies are refused and 17 of 17 weakened verifiers are caught. Fourteen faults planted in the reference (each check of the verification skipped in turn, a legacy receipt, bytes after the envelope, a padded data hash, the identifier without its signer) each fail its tests. The C2PA Rust library (c2pa 0.91.7) reads both good stores beside their envelopes as Trusted with assertion.dataHash.match, and reports assertion.dataHash.mismatch when one envelope byte changes. Co-Authored-By: Claude Opus 5.5 <[email protected]>		2026-11-09 10:50:25 -05:00
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store.c2pa	wai: a C2PA Manifest Store bound to a stored WAI1 or WAI2 envelope, and to the receipt that delivered it	2026-11-09 10:50:25 -05:00