Bump c2pa from 0.88.0 to 0.91.1

[dependabot]

Bumps c2pa from 0.88.0 to 0.91.1.

Changelog

Sourced from c2pa's changelog.

0.91.1

26 September 2026

Added

• Implement pdf manifest writing (backport #2666) (#2700)

Fixed

• Ignore unreferenced claims when reconciling validation statuses (backport #2686) (#2735)
• Validate live OCSP responder certs at current time and complete claim verification on revocation (backport #2688) (#2724)
• Skip only the real C2PA jumb box in JPEG XL box hashing (backport #2695) (#2723)
• CAWG identity assertion mismatch reporting (backport #2713) (#2719)
• Reject invalid RSA public exponents in certificate profiles (CAI-13156) (backport #2712) (#2718)
• Bump id3 to 1.17.2 to cap decompressed ID3v2 frame size (backport #2699) (#2716)
• Check values to avoid underflow in identity flows (backport #2697) (#2711)
• Bound cumulative TIFF IFD entry byte counts to file size (backport #2669) (#2706)
• Reject oversized XMP instead of panicking on JPEG APP1 write (backport #2687) (#2705)
• Harden against integer underflow attacks in XMP trailer parsing (backport #2670) (#2704)

0.91.0

21 September 2026

Breaking changes

• c2pa-raw-crypto split (#2231) — SigningAlg, RawSigner, RawSignerError, RawSignatureValidationError, and the built-in OpenSSL / rust_native_crypto implementations have moved out of c2pa::crypto::raw_signature (now removed) into the separate c2pa-raw-crypto crate. Continue importing these types from the crate root (c2pa::SigningAlg, etc.), which still re-exports them; code that referenced c2pa::crypto::raw_signature::* directly needs updated import paths, and code that needs lower-level access to the raw-signing primitives should depend on c2pa-raw-crypto directly.
• verify_after_sign now defaults to true (#2277) — Settings::verify.verify_after_sign previously defaulted to false in release builds. Builder-created manifests are now re-verified immediately after signing by default, adding a small amount of work per sign in exchange for catching a malformed manifest before it leaves the process. If you relied on the old default, set verify_after_sign = false explicitly.
• Trust-list settings restructured for multiple named trust lists (#2545) — the top-level cawg_trust settings section is gone. C2PA claim-generator, CAWG, and TSA trust configuration now live together under trust.anchors, an array of { trust_uri, trust_kind, trust_anchors, trust_config, allowed_list, trusted_ica_issuers } entries distinguished by trust_kind (e.g. "manifest"), replacing the old single trust.trust_anchors / trust.trust_config / trust.user_anchors / trust.allowed_list fields. A new soft_binding.soft_binding_algorithms setting was also added. If you configure trust via Settings JSON/TOML, update it to the new trust.anchors[] shape — see https://github.com/contentauth/c2pa-rs/blob/c2pa-v0.91.1/docs/context-settings.md for the current schema.
• CAWG X.509 identity assertions use CAWG-specific status codes (#2516) — per CAWG identity assertion spec v1.3 §8.2.2, X.509 identity signature validation now emits cawg.x509.* status codes (e.g. cawg.x509.credential.trusted, cawg.x509.signature.mismatch, cawg.x509.signature.validated) instead of reusing the C2PA claim-signature codes (signingCredential.trusted, claimSignature.mismatch, etc.). Code that inspects ValidationResults or log items for the old codes on this path needs to check for the new cawg.x509.* codes instead.
• CAWG ICA issuers must be explicitly trusted (#2209) — the new trusted_ica_issuers list (part of trust.anchors[], see above) defaults to empty, so no CAWG claims-aggregation issuer is trusted until you list it explicitly; a previously-accepted, unlisted issuer now fails with cawg.ica.untrusted_issuer. Also, CawgValidator is no longer a unit struct: replace &CawgValidator {} with CawgValidator::new(&context) or CawgValidator::default().
• HTTP redirects to non-public hosts are rejected by default (#2433) — fetching a remote manifest, OCSP response, timestamp, or did:web document now validates every redirect hop, not just the initial request, and rejects a hop that resolves to a non-globally-routable address (loopback, RFC1918, link-local/cloud-metadata, etc.) with HttpResolverError::RedirectTargetDisallowed. If your deployment legitimately redirects through an internal host, set core.allow_redirects = false to disable redirect-following, or adjust core.allowed_network_hosts.
• C2PA 2.4 validation rules (#2578) — validation of soft-binding and metadata assertions is relaxed, and Cloud Data / External Reference assertions are validated without fetching, per the C2PA 2.4 spec. This mostly loosens prior rejections; if your code or test fixtures depended on the stricter 2.3-era validation failing for these assertion types, re-check them.
• SVG handler no longer accepts generic XML (#2311) — the SVG asset handler's generic XML fallback is gone. An XML-based format now needs its own specific handler per the C2PA spec's manifest-placement rules (see the new plain-text (#2494) and experimental structured-text (#2283) handlers added in this release); a document that previously round-tripped through the generic SVG/XML path may need a different asset handler.

[!NOTE] This release also carries roughly 70 #[deprecated] items accumulated on main since the last breaking-changes train. None of them are removed in 0.91.0, but per our deprecation policy, the next breaking-changes release — planned for mid-November 2026 — will delete every API still marked deprecated at that point. If your build emits deprecation warnings from c2pa, plan to migrate before that release ships.

Added

• Implement remote signing for CAWG X.509 identity assertions (#2635)
• Add native plain-text asset handler (A.8) (#2494)
• Credential-holder identity signer in the C API (#2603)
• Clean up asset_io, rename things, share common code, and add private registry through Context (#2491)
• Add ZIP support (+ EPUB, Office Open XML, Open Document, and OpenXPS) and Collection Data Hash assertion (#499)
• Add related assertions field and validation to c2pa.actions (#2446)
• Add digital source type field to ingredient (#2447)
• Add support for general boxes hash exclusions (#2513)
• [breaking] Update for C2PA 2.3 spec (#2545)
• (crjson) Implement isUpdateManifest and isCompressedManifest fields (#2185)
• Add Error::AssertionEncoding error source to error message (#2544)

... (truncated)

Commits

• b979441 chore: release v0.91.1 (#2703)
• 3012d72 fix: Ignore unreferenced claims when reconciling validation statuses (backpor...
• 99d867e fix: Validate live OCSP responder certs at current time and complete claim ve...
• d8c72fd ci: Sequence release-plz publish and PR jobs (backport #2698) (#2707)
• 1f9cba9 build: release-plz respects release_commits (fixes #2229) (backport #2658...
• 41ddd7f fix: Skip only the real C2PA jumb box in JPEG XL box hashing (backport #2695)...
• 27bf4e3 fix: CAWG identity assertion mismatch reporting (backport #2713) (#2719)
• 0df0d95 fix: Reject invalid RSA public exponents in certificate profiles (CAI-13156) ...
• bff02c5 fix: bump id3 to 1.17.2 to cap decompressed ID3v2 frame size (backport #2699)...
• be15a42 fix: Check values to avoid underflow in identity flows (backport #2697) (#2711)
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