(.NET Core C#) A3 Certificate Sign PDF to pdf.p7s

Demonstrates how to use an A3/A4 certificate on a smartcard or hardware token to convert a PDF into a .p7s file that contains the PDF within a PKCS7 signature (the .p7s format).

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

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

Chilkat.Cert cert = new Chilkat.Cert();

// If the smartcard or token requires a PIN, we can set it here to avoid the dialog...
cert.SmartCardPin = "000000";

bool success = cert.LoadFromSmartcard("");
if (success != true) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

// Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// The CadesEnabled property applies to all methods that create PKCS7 signatures. 
// To create a CAdES-BES signature, set this property equal to true. 
crypt.CadesEnabled = true;

crypt.HashAlgorithm = "sha256";

// We can sign any type of file, creating a .p7s as output.
// The .p7s contains the signature and also embeds the data of the file that is signed.
string inFile = "qa_data/pdf/sample.pdf";
string p7sFile = "qa_output/sample.pdf.p7s";

// Create the CAdES-BES attached signature, which contains the original data.
// Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
// is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
// is NOT contained within the signature.  We want the data to be contained in the signature, therefore
// we call CreateP7M even though we are naming our output file .p7s.
success = crypt.CreateP7M(inFile,p7sFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Verify the .p7s file and extract the original file from the .p7s. 
string extractedToFilePath = "qa_output/sample.pdf";
success = crypt.VerifyP7M(p7sFile,extractedToFilePath);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine("Success!");