How to set password for an existing PDF?
Posted on StackOverflow on Dec 2, 2014 by Sreekanth P
It's as simple as this:
public void encryptPdf(String src, String dest) throws IOException, DocumentException { PdfReader reader = new PdfReader(src); PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest)); stamper.setEncryption(USER, OWNER, PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128 | PdfWriter.DO_NOT_ENCRYPT_METADATA); stamper.close(); reader.close(); }
Note that USER and OWNER are of type byte[]. You have different options for the permissions (look for constants starting with ALLOW_) and you can choose from different encryption algorithms.