THPDFHeadlessDocument.AddSignatureValidationEvidence

function AddSignatureValidationEvidence(SignatureIndex: Integer;
  const Evidence: THPDFHeadlessLTVEvidence;
  const Options: THPDFHeadlessLTVOptions): THPDFHeadlessLTVResult;

Authenticates the selected signed signature and its revocation evidence, then prepares a DSS and VRI incremental update in the loaded document

SignatureIndex selects a zero-based signed signature, rather than a form-field index; TrustedCAFile must contain explicit PEM trust roots

The signature content digest, signer signature and chain, and the required timestamp are verified against the original PDF ByteRanges before any document graph mutation

Evidence supplies complete DER OCSP responses or issuer CRLs covering all non-anchor signer and TSA chain certificates; optional DER certificates supplement chain construction

Call SaveToFile with a distinct output path after success; the original signed revision stays intact and newly generated AES evidence streams remain encrypted

Document and evidence cancellation tokens must match when both are provided; document limits constrain evidence limits, generated stream sizes, object counts and remaining incremental output bytes

Encrypted sources require document modification permission or owner authentication; invalid evidence, denied permissions, exhausted budgets and cancellation leave the graph unchanged

See Native signature validation evidence for validation scope and archival limitations