(C# UWP/WinRT) Sign a File to Create a .p7m File (using a PFX)

C# UWP/WinRT example to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// 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 = null;
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 .p7m as output:
string inFile = "/Users/chilkat/testData/pdf/sample.pdf";
string outputFile = "/Users/chilkat/testData/p7m/sample.pdf.p7m";
success = await crypt.CreateP7MAsync(inFile,outputFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);

    return;
}

// Verify and restore the original file:
success = crypt.SetVerifyCert(cert);

inFile = outputFile;
outputFile = "/Users/chilkat/testData/pdf/restored.pdf";

success = crypt.VerifyP7M(inFile,outputFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);

    return;
}

Debug.WriteLine("Success!");