(.NET Core C#) PKCS11 Sign PDF using Certificate and Private Key on Smart Card / USB Token

See more PKCS11 Examples

Sample code showing how to use PKCS11 to sign a PDF with a certificate and private key stored on a smart card or USB token.

Note: This example requires Chilkat v9.5.0.96 or later.

Chilkat .NET Downloads Chilkat .NET Assemblies Chilkat for .NET Core Chilkat for Mono

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

Chilkat.Pkcs11 pkcs11 = new Chilkat.Pkcs11();

pkcs11.SharedLibPath = "C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS1164.dll";
string pin = "0000";
int userType = 1;

// Establish a PKCS11 logged-on session using the driver (.so, .dylib, or .dll) as specified in the SharedLibPath above.
bool success = pkcs11.QuickSession(userType,pin);
if (success == false) {
    Debug.WriteLine(pkcs11.LastErrorText);
    return;
}

// Get the certificate (on the smart card) that has a private key.
// There are other ways to locate a certificate on the HSM.
// This example assumes there is a single certificate w/ private key.
Chilkat.Cert cert = new Chilkat.Cert();
success = pkcs11.FindCert("privateKey","",cert);
if (success == true) {
    Debug.WriteLine("Cert with private key: " + cert.SubjectCN);
}
else {
    Debug.WriteLine("No certificates having a private key were found.");
    success = pkcs11.CloseSession();
    return;
}

// --------------------------------------------------------------------------
// At this point, we have the cert to be used for signing.
// Our PDF signing code is the same as for a cert obtained from any other source..

Chilkat.Pdf pdf = new Chilkat.Pdf();

// Load a PDF to be signed.
success = pdf.LoadFile("qa_data/pdf/hello.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    success = pkcs11.CloseSession();
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();

json.UpdateInt("page",1);
json.UpdateString("appearance.y","top");
json.UpdateString("appearance.x","left");
json.UpdateString("appearance.fontScale","10.0");
json.UpdateString("signingAlgorithm","pss");
json.UpdateString("hashAlgorithm","sha256");

int i = 0;
json.I = i;
json.UpdateString("appearance.text[i]","Digitaly signed by: Xyz Widgets, Inc.");
i = i + 1;
json.I = i;
json.UpdateString("appearance.text[i]","current_dt");
i = i + 1;
json.I = i;
json.UpdateString("appearance.text[i]","blah blah blah");

// The certificate is internally linked to the Pkcs11 object, which is currently in an authenticated session.
success = pdf.SetSigningCert(cert);

success = pdf.SignPdf(json,"qa_output/out.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    success = pkcs11.CloseSession();
    return;
}

// --------------------------------------------------------------------------

// Revert to an unauthenticated session by calling Logout.
success = pkcs11.Logout();
if (success == false) {
    Debug.WriteLine(pkcs11.LastErrorText);
    success = pkcs11.CloseSession();
    return;
}

// When finished, close the session.
// It is important to close the session (memory leaks will occur if the session is not properly closed).
success = pkcs11.CloseSession();
if (success == false) {
    Debug.WriteLine(pkcs11.LastErrorText);
    return;
}

Debug.WriteLine("Success.");