Iterative Digital signing of the PDF document Leave feedback

GroupDocs.Signature provides DigitalSignOptions class to specify different amount of settings for Digital signature

• digital certificate (file on local disk CertificateFilePath or stream CertificateStream) (required)
• password of digital certificate Password (required)
• digital signature details (Reason, Contact, Location)

Here are the steps to add Digital signature into document with GroupDocs.Signature:

• Define the paths for the input PDF file, the digital certificates, and specify the output path where the signed documents will be saved.
• Create a new instance of the Signature class and pass the source document path as a constructor parameter.
• Instantiate the DigitalSignOptions object with the required certificate and its password, and configure additional properties such as reason, contact, location, and position.
• Call the Sign method of Signature class instance and pass DigitalSignOptions to it.
• After signing, update the document path for the next iteration.
• Analyze the SignResult to check the newly created signatures if needed.
• Iterate through each certificate, repeating the above steps for each one.

This example demonstrates how to iteratively sign a PDF document with multiple digital certificates. See SignResult

string filePath = "sample.pdf";
string fileName = Path.GetFileName(filePath);

string[] certificatePaths = new string[] { "certificate1.pfx", "certificate2.pfx" };

string outputFilePath = Path.Combine("output folder path", "SignWithDigitalIterative", fileName);
int iteration = 1;
string documentFile = filePath;

foreach (var certificatePath in certificatePaths)
{
    using (Signature signature = new Signature(documentFile))
    {
        DigitalSignOptions options = new DigitalSignOptions(certificatePath)
        {
            Password = "1234567890", // Certificate password
            Reason = $"Approved-{iteration}", // Digital certificate details
            Contact = $"John{iteration} Smith{iteration}",
            Location = $"Location-{iteration}",
            AllPages = true, // Sign all pages
            Left = 10 + 100 * (iteration - 1),
            Top = 10 + 100 * (iteration - 1),
            Width = 160,
            Height = 80,
            Margin = new Padding() { Bottom = 10, Right = 10 }
        };

        SignResult signResult = signature.Sign(outputFilePath, options);
        documentFile = outputFilePath;
        Console.WriteLine($"\nSource document signed successfully {iteration++}-time with {signResult.Succeeded.Count} signature(s).\nFile saved at {outputFilePath}.");
    }
}

You may easily run the code above and see the feature in action in our GitHub examples:

• GroupDocs.Signature for .NET examples, plugins, and showcase
• GroupDocs.Signature for Java examples, plugins, and showcase
• Document Signature for .NET MVC UI Example
• Document Signature for .NET App WebForms UI Example
• Document Signature for Java App Dropwizard UI Example
• Document Signature for Java Spring UI Example

Along with the full-featured .NET library, we provide simple but powerful free online apps.

To sign PDF, Word, Excel, PowerPoint, and other documents you can use the online apps from the GroupDocs.Signature App Product Family.