Question

I am getting this error while trying to digitally sign the PDF document.
passing the two pdfs SOURCEPDF name and DESTINATIONPDF name(digitally SIGNED) pdf name.
after first digital signing on SOURCEPDF i get DESTINATIONPDF .
for second digital signing am using DESTINATIONPDF as a source pdf as well as destination pdf.

Here is my code

try
{
    for(int i=1;i<=signature_Count;i++)
    {
        if(i==1)
        {
            tmpPdfSource=sourcePdfPath;
        }else{
            this.tmpPdfSource=destinationPdfPath;
        }

        int pageNo=Integer.parseInt(ad.readXML(xmlString, rootName,"PageNo-"+i));
        String imageSource=ad.readXML(xmlString, rootName,"ImageSource-"+i);
        float llx=Float.parseFloat(ad.readXML(xmlString, rootName,"llx-"+i));
        float lly=Float.parseFloat(ad.readXML(xmlString, rootName,"lly-"+i));
        float urx=Float.parseFloat(ad.readXML(xmlString, rootName,"urx-"+i));
        float ury=Float.parseFloat(ad.readXML(xmlString, rootName,"ury-"+i));
        String signature=ad.readXML(xmlString, rootName,"SignatureName-"+i);

        File dest = new File(destinationPdfPath);
        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
        ks.load(new Fil eInputStream(certificatePath), keystore_password.toCharArray());
        String alias = (String) ks.aliases().nextElement();
        PrivateKey pk = (PrivateKey) ks.getKey(alias,key_password.toCharArray());
        java.security.cert.Certificate[] chain = ks.getCertificateChain(alias);
        PdfReader reader = new PdfReader(tmpPdfSource);
        stamper = PdfStamper.createSignature(reader,new FileOutputStream(dest), '\0', null, true);
        PdfSignatureAppearance appearance = stamper.getSignatureAppearance();

        appearance.setCrypto(pk, chain, null,PdfSignatureAppearance.SELF_SIGNED);

        if (true)
        {
            appearance.setAcro6Layers(true);
            Image img=Image.getInstance(imageSource);
            appearance.setImage(img);
            appearance.setVisibleSignature(new com.itextpdf.text.Rectangle(llx, lly, urx, ury), pageNo, signature);
        }
    }//for
    stamper.close();
} catch (Exception e) {
    GenericLog gl=new  GenericLog();
    gl.writeWarning("Error Occured in SignPdfDocument ");
    gl.writeError(e);
    e.printStackTrace();
}

please Help me to FIX this error.

Answer 1

I see the method setCrypto() which means you’re not using the latest version of iText; I also see the option PdfSignatureAppearance.SELF_SIGNED which means you’re creating a signature that doesn’t conform with today’s standards anymore.

Would you please do yourself a favor and read the documentation?

Also: you’re using the same file as the source and the destination? That’s impossible. You need at least to create a temporary file or create the file in memory, and then overwrite the existing one.