java - iTextPdf setEncryption 没有权限

Question

我正在使用这样的密码加密 pdf:

public static void main(String[] args) throws DocumentException, MalformedURLException, IOException {
    Document document = new Document();
    PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("zrsz.pdf"));
    writer.setEncryption("ownerPass".getBytes(), "userPass".getBytes(), PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128);
        writer.createXmpMetadata();
        document.open();
        document.add(new Paragraph("This is create PDF with Password demo."));
    document.close();
    System.out.println("Done");
   }

但我找不到向此 setEncryption 方法提供“无权限”参数的方法:

public void setEncryption(byte[] userPassword,
                          byte[] ownerPassword,
                          int permissions,
                          int encryptionType)

这可能吗？我想将对该文件的访问限制在最低限度。我只是用它来读取 secret 数据。

提前致谢!

Answer 1

根据手册，您可以使用以下所有内容作为 Docs说

Sets the encryption options for this document. The userPassword and the ownerPassword can be null or have zero length. In this case the ownerPassword is replaced by a random string. The open permissions for the document can be AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations, AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting

使用用户密码打开文档时允许执行上述所有操作。因此，您有一个安全措施，只有输入有效凭据(密码)的用户才能操作它。