(C#) Sign a File to Create a .p7s (Detached Signature)

C# example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

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

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

// Use a digital certificate and private key from a PFX file (.pfx or .p12).
string signingCertSubject = "Acme Inc";
string pfxFilename = "/Users/chilkat/testData/pfx/acme.pfx";
string pfxPassword = "test123";

Chilkat.CertStore certStore = new Chilkat.CertStore();
bool success = certStore.LoadPfxFile(pfxFilename,pfxPassword);
if (success != true) {
    Debug.WriteLine(certStore.LastErrorText);
    return;
}

Chilkat.Cert cert = certStore.FindCertBySubjectCN(signingCertSubject);
if (certStore.LastMethodSuccess == false) {
    Debug.WriteLine("Failed to find certificate by subject common name.");
    return;
}

// Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert);

// We can sign any type of file, creating a .p7s as output:
string inFile = "/Users/chilkat/testData/pdf/sample.pdf";
string sigFile = "/Users/chilkat/testData/p7s/sample.p7s";

success = crypt.CreateP7S(inFile,sigFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);

    return;
}

success = crypt.VerifyP7S(inFile,sigFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);

    return;
}

Debug.WriteLine("Success!");