Digitally sign PDF document - Aspose.PDF - unknown signature

Programming in C#.NET.

If I upload pdf file with digital signature using aspose, error occurs as shown below.

source info :
(fileStream is memory stream of pdf file with digital signature.)

Aspose.Pdf.Document pdfDocTemp = new Aspose.Pdf.Document(fileStream);

                                        Aspose.Pdf.Document pdfDoc = new Aspose.Pdf.Document();
                                        
                                        int tempPagecnt = pdfDocTemp.Pages.Count;
                                        for (int tempPageCount = 1; tempPageCount <= tempPagecnt; tempPageCount++)
                                        {
                                            pdfDoc.Pages.Add(pdfDocTemp.Pages[tempPageCount]);
                                        }
                                        var pdfStreamNew = new MemoryStream();
                                        pdfDocTemp.Save(pdfStreamNew);

                                        blob = blobContainer.GetBlobReference(companyId + "\\" + loanId + "\\" + fileName + "." + fileExt);
                                        blob.DeleteIfExists();
                                        blob.UploadFromStream(pdfStreamNew);

                                        Stream tempMemoryStream = new MemoryStream();

error info :

Signature validity is UNKOWN.

  • The document has not been modified since this signature was applied.
  • The signer`s identity is unknown because it has not been included in your list of trusted certificates and none of its parent certificates are truested certificates.

Screenshot 2022-03-30 133253.png (24.0 KB)

@Lay_Kim

To ensure a timely and accurate response, please attach the following resources here for testing:

  • Your input PDF.
  • Please attach the output PDF that shows the undesired behavior.
  • Please create a standalone console application (source code without compilation errors) that helps us to reproduce your problem on our end and attach it here for testing.

As soon as you get these pieces of information ready, we will start investigation into your issue and provide you more information. Thanks for your cooperation.

PS: To attach these resources, please zip and upload them.