Get the signature state. Use this function to find out if the document is still identical to the signed document, or has been updated since signed, or has been tampered with. If the state is ss_unsupported_signature or ss_invalid_certificate, getErrorMessage() will provide additional information. Use verifyCertificateChain() to find out if you can trust the identity of the signer. If the return value is #ss_document_extended for a PDF document, you should call getModificationState() to get additional information.

public SignatureState getState()