THPDFSignatureInputKind Type

Tells a signature provider whether the request input carries the raw message or a precomputed digest

Declaration

THPDFSignatureInputKind= (
  sikMessage,
  sikDigest
  );

HPDFSignatureProvider

Value	Purpose
`sikMessage`	The request input holds the message bytes themselves; PureEdDSA providers such as Ed25519 and Ed448 require this and hash internally
`sikDigest`	The request input holds an already computed digest; digest-based signers such as RSA and ECDSA require this

Providers reject a request whose input kind does not match their algorithm with spsMalformed, so check the algorithm before filling the request
With sikMessage there is no separate hashing step, which is exactly what PureEdDSA expects; any digest you pass would be signed as opaque data
Use sikDigest when the bytes to hash are already consumed elsewhere, for example while the placeholder digest was computed during signing