verify_signature

org.nsgoods/nsgoods-workbench-mcp · Verify this server

Offline EIP-191 verify of a signed nsgoods response. Identifies the service from the manifest (or the optional `service` arg), strips exactly that service's post-sign fields, canonicalises (JCS, both ASCII modes), recovers the signer and checks it against the published manifest signers. Reproduction-attestation (JCS/byte-length) and envelope (signer/signature, components) shapes are reported as unsupported_shape, not verified here. Refusals carry a distinct status: malformed_signature (signature is not a 65-byte 0x-prefixed hex string), schema_rejected (the body carries a signed_by/signature pair but fails the required field shape for every service the claimed signer covers; recovery was not attempted, checked is false, reasons lists the failed candidates), signature_mismatch (well-formed but recovers a different address than signed_by under every candidate service recipe of this signer), no_flat_recipe (signed_by is a manifest signer but every service it covers uses an envelope shape, so there is no flat recipe to check; recovery was not attempted, checked is false), unknown_signer (signed_by is not a manifest signer; recovery was not attempted, checked is false), unsupported_shape, or the no-signed_by/signature-pair case. checked is true only when EIP-191 recovery actually ran; every other refusal reports checked false.