PPTX DOCX XLSX PDF ODP
Aspose.PDF  for .NET
PDF

Add digital signature in PDF using via C#

Native and high performance PDF document digital signature generation and verification using server-side Aspose.PDF for .NET APIs, without the use of any software including Adobe PDF - C#.

How to add Digitally Sign to PDF File Using .NET Library

In order to add digital signature in PDF file, we’ll use Aspose.PDF for .NET API which is a feature-rich, powerful and easy to use document manipulation API for net platform. Open NuGet package manager, search for Aspose.PDF and install. You may also use the following command from the Package Manager Console.

Package Manager Console Command


            PM > Install-Package Aspose.PDF
        

Add Digitally Sign to PDF via C#

You need Aspose.PDF for .NET to try the code in your environment.

  1. Load the PDF with an instance of Document.
  2. Load all the PDF files with full path.
  3. Set the style of text like font, font size, color etc.
  4. Save PDF file, You will get the document with signature inserted.
  5. To verify the validity of the signature use PdfFileSignature.VerifySigned() method.

System Requirements

Just make sure that you have the following prerequisites.

  • Microsoft Windows or a compatible OS with .NET Framework, .NET Core, and PHP, VBScript, Delphi, C++ via COM Interop.
  • Development environment like Microsoft Visual Studio.
  • Aspose.PDF for .NET DLL referenced in your project.
 

Add Electronic Signature to a PDF File using - C#.

public static void SignDocument()
{
    string inFile = System.IO.Path.Combine(_dataDir,"DigitallySign.pdf");
    string outFile = System.IO.Path.Combine(_dataDir,"DigitallySign_out.pdf");
    using (Document document = new Document(inFile))
    {
        using (PdfFileSignature signature = new PdfFileSignature(document))
        {
            PKCS7 pkcs = new PKCS7(@"C:\Keys\test.pfx", "Pa$$w0rd2020"); // Use PKCS7/PKCS7Detached objects
            signature.Sign(1, true, new System.Drawing.Rectangle(300, 100, 400, 200),pkcs);
            // Save output PDF file
            signature.Save(outFile);
        }
    }
}
 

About Aspose.PDF for C# API

Aspose.PDF API can be used for PDF document manipulation and parsing within applications. One can create, modify, compress, secure, print or save PDF to TXT, HTML, PCL, XFA, XML, XPS, EPUB, TEX, Images and more formats. Aspose.PDF is a standalone API and it does not depend on any software including Adobe Acrobat.

Online PDF eSignature Live Demos