我使用iText创建和加密pdf

                    string inputfile = "input file path";
                    string outfile = "outfile file path";
                    using (Stream output = new FileStream(outfile, FileMode.Create, FileAccess.Write, FileShare.None))
                    {
                        PdfReader reader = new PdfReader(inputfile);             
                        Dictionary<string, string> newInfo = new Dictionary<string, string>();
                        newInfo.Add("Title", "Title");
                        newInfo.Add("Subject", "Subject");
                        newInfo.Add("Keywords", "Keywords");
                        newInfo.Add("Creator", "Creator");
                        newInfo.Add("Author", "Author");
                        newInfo.Add("CustomInfo", "CustomeInformationCanStoreHere");                           
                        PdfEncryptor.Encrypt(reader,output,true,"*****","*****",PdfWriter.DO_NOT_ENCRYPT_METADATA, newInfo);
                    }

我已经加密PDF文件使用上述代码(密码和设置选项为PdfWriter.DO_NOT_ENCRYPT_METADATA)

作为选项建议(DO_NOT_ENCRYPT_METADATA)我不希望元数据被加密，但它仍然加密元数据，如标题，主题，作者，关键词信息..

上面的代码有什么遗漏吗?

public void manipulatePdf(string source, string destination) {
        PdfReader reader = new PdfReader(source);
        Stream output = new FileStream(destination, FileMode.Create, FileAccess.Write, FileShare.None);
        PdfStamper stamper = new PdfStamper(reader, output);
        Dictionary<string, string> newInfo = new Dictionary<string, string>();
        newInfo.Add("Title", "Title");
        newInfo.Add("Subject", "Subject");
        newInfo.Add("Keywords", "Keywords");
        newInfo.Add("Creator", "Creator");
        newInfo.Add("Author", "Author");
        newInfo.Add("CustomInfo", "CustomeInformationCanStoreHere");
        stamper.MoreInfo = newInfo;             
        MemoryStream outStream = new MemoryStream();
        XmpWriter xmpw = new XmpWriter(outStream,newInfo);            
        stamper.XmpMetadata = outStream.ToArray();            
        byte[] password = Encoding.ASCII.GetBytes("password");            
        stamper.SetEncryption(password, password, PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128 | PdfWriter.DO_NOT_ENCRYPT_METADATA);
        xmpw.Close();
        stamper.Close();
        reader.Close();
    }