question: public LtvVerifier ( PdfDocument document ) throws GeneralSecurityException { super ( null ) ; this . document = document ; this . acroForm = PdfAcroForm . getAcroForm ( document , true ) ; this . sgnUtil = new SignatureUtil ( document ) ; List < String > names = sgnUtil . getSignatureNames ( ) ; signatureName = names . get ( names . size ( ) - 1 ) ; this . signDate = DateTimeUtil . getCurrentTimeDate ( ) ; pkcs7 = coversWholeDocument ( ) ; LOGGER . info ( MessageFormat . format ( "Checking {0}signature {1}" , pkcs7 . isTsp ( ) ? "document-level timestamp " : "" , signatureName ) ) ; }
target:  Creates a VerificationData object for a PdfReader