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++)
                                        var pdfStreamNew = new MemoryStream();

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

                                        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)


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  • 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.

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