(Mono C#) Sign a File to Create a .p7m File (using a PFX)

Mono C# 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 .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.

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 = crypt.CreateP7M(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!");