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PDF Signatures


The details of how to implement and use the digital signature capability for PDF files can be found in the SDK’s sample application.

The directory "pdf_sign" contains example implementations of the classes required for signing. The code contains details of how each class works for an application developer to follow.

SampleSignerFactory is the digital signature factory, which creates instances of SampleSigner and SampleVerifier

SampleSigner handles the signing process.

SampleVerifier verifies the validity of a signature.

SampleCertificateStore provides access to your own X509 certificate store. This example contains three hard-coded certificates.

SampleCertificatePicker presents a dialog for choosing which certificate to use for signing.

SampleCertificateViewer presents a certificate viewer dialog, similar to the SampleCertificatePicker dialog, in order to show details of the certificate used for signing.

During app initialization, an application developer registers a signer factory with the SDK. This example is from the sample app:

val mSignerFactory:SampleSignerFactory? = SampleSignerFactory.getInstance()

if (mSignerFactory != null) {
final SampleSignerFactory mSignerFactory = SampleSignerFactory.getInstance();

if (mSignerFactory != null) {

Or, you can can enable a default implementation by registering an instance of NUIDefaultSignerFactory.