Add a Detached Signature (Separate Key, Header Control)

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Demonstrates the Chilkat Mime.AddDetachedSignaturePk2 method, which creates a detached signature with a separately supplied certificate and private key, and a third argument controlling transfer of the existing message header fields to the new outer entity.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This combines the two variations — certificate and key supplied separately, plus explicit header placement — for the case that needs both. It is the most flexible of the detached-signature methods; choose it when your key material is separate and you also care about where the message headers end up on the signed result.

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bool success = false;

Chilkat.Mime mime = new Chilkat.Mime();
success = mime.SetBodyFromPlainText("This message will be signed.");
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  Load the certificate and its private key separately.
Chilkat.Cert cert = new Chilkat.Cert();
success = cert.LoadFromFile("qa_data/signer.cer");
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();
success = privKey.LoadPemFile("qa_data/signer_privkey.pem");
if (success == false) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

//  Create a detached signature with separately supplied cert and private key, where the 3rd
//  argument controls whether the existing message header fields are transferred to the new outer
//  multipart/signed entity.
bool transferHeaderFields = true;
success = mime.AddDetachedSignaturePk2(cert,privKey,transferHeaderFields);
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

success = mime.SaveMime("qa_output/signed.eml");
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

Debug.WriteLine("Detached signature added (headers transferred).");