Add Digital Signatures to PDFs

How to Add Visible Digital Signature to PDF

The following steps and C# sample code illustrate adding a visible digital signature to a PDF using DynamicPDF Core Suite for .NET.

Steps for Adding a Visible Digital Signature to a PDF Document

1. Create a Document object.
2. Create a Page object.
3. Create a Signature object and set its properties in the constructor.
4. Add the Signature object to the Page object.
5. Add the Page object to the Document object.
6. Create a Certificate object and set its properties.
7. Sign the document with the Visible Digital Signature field name.
8. Save the PDF document.

Sample Code - C#

Document document = new Document();
Page page = new Page(PageSize.Letter);        
Signature signature = new Signature("SigField", 10, 10, 250, 100);
page.Elements.Add(signature);
document.Pages.Add(page);
Certificate certificate = new Certificate("JohnDoe.pfx", "password");
document.Sign("SigField", certificate);
document.Draw("Output.pdf");        

How to Add Invisible Digital Signature to PDF

The following steps and C# sample code add an invisible Digital Signature to a PDF document using DynamicPDF Core Suite for .NET.

Steps for Adding an Invisible Digital Signature to a PDF Document

1. Create a Document object.
2. Create a Page object.
3. Add the Page instance to the Document instance.
4. Create a Certificate object and set its properties.
5. Sign the document with a non-existent field name and the Certificate.
6. Save the PDF document.

Sample Code - C#

Document document = new Document();
Page page = new Page();
document.Pages.Add(page);
Certificate certificate = new Certificate(@"JohnDoe.pfx", "password");
document.Sign("NonExistingField", certificate);
document.Draw("Output.pdf");         

GitHub Project

Examples are provided in C# and VB.NET. Clone or view the example project at GitHub. This example code is contained in the following examples.

• C# - CertificateExample.cs
• VB.NET - CertificateExample.vb

Getting Started

Get started easily by installing DynamicPDF Core Suite for .NET through NuGet or manually. Then, refer to the documentation for more information on using and purchasing.

NuGet Package

The easiest way to install DynamicPDF Core Suite is by obtaining the NuGet package using Visual Studio's Package Manager. You can also obtain the NuGet package by downloading it directly. Refer to the installation documentation for more information.

DynamicPDF Core Suite Information

DynamicPDF Core Suite for .NET combines creating, merging, and visual report creation into one powerful product for creating PDF documents. It is ideal for anyone who needs to generate PDF documents or reports or work with existing PDFs in their applications. With a free Evaluation Edition to try and with flexible and royalty-free licensing options, why not start using DynamicPDF Core Suite for .NET today!

• DynamicPDF Core Suite for .NET Product Page
• DynamicPDF Core Suite for .NET Documentation

More Information on Digital Signatures

• Refer to the Digital Signing and Certifying documentation topic, or
• Chapter 14, Securing PDF Documents, in the book DynamicPDF Core Suite for .NET by Example available on GitHub.

Available on Other Platforms

DynamicPDF Core Suite is also available for the Java and COM/ActiveX platforms. Refer to the respective product pages for more details.

• DynamicPDF Generator
  • Java - DynamicPDF Generator for Java
  • COM/ActiveX - DynamicPDF Generator for COM/ActiveX
• DynamicPDF Merger
  • Java - DynamicPDF Merger for Java
  • COM/ActiveX - DynamicPDF Merger for COM/ActiveX