Java

Add a Detached Signature with a Separate Private Key

Demonstrates the Chilkat Mime.AddDetachedSignaturePk method, which creates a detached signature using a signer certificate and its separately supplied private key. The first argument is the Cert and the second is the PrivateKey.

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: Sometimes the certificate and its private key live apart — a .cer alongside a PEM key file, for instance — rather than bundled in a single PFX. This method pairs them explicitly for signing, whereas AddDetachedSignature expects a Cert that already provides its key. The result is the same multipart/signed message.

Chilkat Java Downloads

Download Chilkat for Java

Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Mime;
import com.chilkatsoft.chilkat2.PrivateKey;

public class ChilkatExample {

    public static void main(String[] args) {
        Mime mime = new Mime();
        try {
            mime.setBodyFromPlainText("This message will be signed.");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Load the certificate and its private key separately.
        Cert cert = new Cert();
        try {
            cert.loadFromFile("qa_data/signer.cer");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        PrivateKey privKey = new PrivateKey();
        try {
            privKey.loadPemFile("qa_data/signer_privkey.pem");

            // Create a detached signature when the certificate and private key are supplied separately.  The
            // 1st argument is the signer certificate and the 2nd is its private key.
            mime.addDetachedSignaturePk(cert, privKey);

            mime.saveMime("qa_output/signed.eml");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Detached signature added.");
    }
}