How to search for Digital signatures

GroupDocs.Signature offers an ability to findΒ Digital signatures that are applied to document and returns its digital signature certificate.
Please follow these steps to search for DigitalΒ signatures within the document:

This example shows how to search for Digital signature in the document and analyze digital signature certificate.

            using (Signature signature = new Signature("spreadsheet.xlsx"))
            {
                // search for signatures in document
                List<DigitalSignature> signatures = signature.Search<DigitalSignature>(SignatureType.Digital);

                Console.WriteLine("\nSource document contains following signatures.");
                foreach (var digitalSignature in signatures)
                {
                    Console.WriteLine("Digital signature found from {0} with validation flag {1}. Certificate SN {2}",
                    digitalSignature.SignTime, digitalSignature.IsValid, digitalSignature.Certificate?.SerialNumber);
                }
            }

Advanced Usage Topics

To learn more about document eSign features, please refer to theΒ advanced usage section.

More resources

GitHub Examples

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

Free Online Apps

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.