DataProofsDotnet.Legacy 2.0.0

dataproofs-dotnet

Securing mechanisms for documents and credentials in .NET — the single home for both proof families defined by the W3C and IETF securing-mechanism landscape.

All cryptography routes through NetCrypto; all multiformats (multibase, multicodec, Multikey) and JCS through NetCid. Keys held in a NetCrypto IKeyStore are never exported — signing accepts an ISigner or key-store alias, and JWE ECDH key agreement accepts an opaque IEcdhKey, never raw private bytes.

Getting started

git clone https://github.com/moisesja/dataproofs-dotnet.git
cd dataproofs-dotnet
dotnet build DataProofsDotnet.sln
dotnet test DataProofsDotnet.sln

Runnable, narrated examples for every feature live under samples/ — each doubles as a CI smoke test. Start with samples/README.md.

RDFC canonicalization fails closed on data loss

JSON-LD processing drops what it cannot turn into RDF, and whatever it drops is not signed. So the RDFC suites (eddsa-rdfc-2022, ecdsa-rdfc-2019, bbs-2023, and the Legacy RDFC variant) refuse such input instead of signing less than the document says (VC Data Integrity 1.0 §2.4.3):

• Creating a proof throws ProofGenerationException with an inner JsonLdDataLossException.
• Verification fails with DATA_LOSS_DETECTION_ERROR. A Legacy suite reports that code only when constructed with LegacyVariantVerification.ConstructedVariantOnly. By default it also tries the JCS variant, and it reports PROOF_VERIFICATION_ERROR or PROOF_TRANSFORMATION_ERROR.

Typical causes:

• A term no @context defines. credentials/v2 has no @vocab. Define your terms, or list https://www.w3.org/ns/credentials/undefined-terms/v2 last, as VCDM 2.0 §5.2 requires. The offline loader bundles that context.
• Proof terms no @context defines. A credentials/v1 document also needs https://w3id.org/security/data-integrity/v2. The Legacy RDFC variant needs https://w3id.org/security/suites/ed25519-2020/v1. Both are bundled.
• An IRI that is not well formed. Examples: ?filter[id]=1, a second #, a space, a relative IRI.
• An IRI the canonical form would respell. Examples: /a/../b, %41, HTTPS://HOST, :443. Relative IRIs resolved against an @base are respelled too, so they are refused.
• Distinct IRIs dotNetRDF treats as one. Example: https://host next to https://host/. Their statements would merge.
• A boolean or number with @direction. dotNetRDF types it as an XSD literal and drops the direction.

A string's base direction is carried, not refused. {"@value":"x","@language":"ar","@direction":"rtl"} is signed as "x"^^<https://www.w3.org/ns/i18n#ar_rtl>, the JSON-LD 1.1 rdfDirection: i18n-datatype representation that the reference Data Integrity implementations (jsonld-signatures and the cryptosuites built on it) sign with; the Data Integrity specifications name none. Flipping the direction breaks the proof. A verifier whose JSON-LD processor drops direction, the JSON-LD default, does not verify these proofs, as it does not verify theirs. The canonical form is byte-identical with jsonld.js for the VCDM 2.0 value-object shapes. The CHANGELOG lists the three differences on its side; the one to know is that jsonld.js drops a context-level default @direction from a credentials/v2 credential, so write the direction on the value object.

RDFC uses a local corrected copy of dotNetRDF's canonicalizer for tied blank nodes (dotnetrdf/dotnetrdf#917), with work/depth guards and Unicode code-point ordering. The committed 1,870-case corpus matches rdf-canonize 5.0.0; that implementation's UTF-16 ordering nevertheless differs from the standard when supplementary characters compete with U+E000–U+FFFF characters. This library follows the standard in that case, so those proofs do not cross-verify with that version. The CHANGELOG explains the affected old proofs and issuer-driven reissuance requirements.

An RDFC or bbs-2023 proof verifies only if the proof options the library reads (expires, domain, challenge, proofPurpose, …) are what the issuer signed, whatever @context says. That does not reach what the library does not read: @context is not signed, so an application acting on a document claim or an unmodeled proof member must pin its contexts.

ProofVerificationOptions.KnownContexts is a URI allowlist, not content authentication. Use it with approved immutable offline contexts or a loader that checks approved hashes of context content and its dependencies. Validate any stricter context-order/nesting profile separately. See the BBS service admission example for concrete request/shape/proof/concurrency limits; the library's canonicalizer work budget does not cover JSON-LD expansion or native BBS verification.

Native AOT and trimming

All six packages declare IsAotCompatible: they build with zero trim, single-file and AOT analyzer warnings, and every System.Text.Json (de)serialization uses source-generated metadata, so they work in trimmed and native-AOT applications and in .NET 10 file-based apps. CI job ac-12 runs tasks/aot-smoke, which exercises every package, under JIT, with reflection-based serialization disabled, as a file-based app and as a native-AOT binary, and requires byte-identical output from all four. As a consumer:

• DataProofsJsonOptions.Default serializes the library's own types through source-generated metadata in every host. For your types it falls back to reflection only where the host enables it. In a trimmed or AOT application, or any project with PublishAot, register them in your own JsonSerializerContext.
• DataIntegrityProof can be listed in your own context directly ([JsonSerializable(typeof(DataIntegrityProof))]); its previousProof converter is public for that reason.
• Publishing Rdfc, Legacy or the DI package with native AOT surfaces warnings from Newtonsoft.Json, dotNetRdf.Core's dependency, for dynamic support the RDFC path never reaches (IL2104/IL3053). Under TreatWarningsAsErrors they fail the publish; to keep them visible but not fatal, add <WarningsNotAsErrors>$(WarningsNotAsErrors);IL2104;IL3053</WarningsNotAsErrors>. That makes every dependency's collapsed trim/AOT warnings non-fatal, not only Newtonsoft.Json's, so check that each IL2104/IL3053 in your publish log names Newtonsoft.Json and nothing else. Core, Jose and Cose produce no IL warnings.

Design documents

• dataproofs-concept.md — vision and decisions log (binding)
• dataproofs-prd.md — requirements; the main source of truth
• CONTRIBUTING.md · SECURITY.md · CHANGELOG.md

License

Apache-2.0. See LICENSE.