Android™
Android™
Add an S/MIME Detached Signature
See more MIME Examples
Demonstrates the Chilkat Mime.AddDetachedSignature method, which creates an S/MIME detached signature. The only argument is the signing Cert, which must have access to its private key. On success the entity becomes a multipart/signed with the content and a separate signature part.
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: A detached signature (
multipart/signed) keeps the original content readable alongside a separate signature part — so recipients whose software does not understand S/MIME still see the message, they just cannot verify it. That backward compatibility makes detached the usual choice for signed email. The signer proves authorship with a certificate that carries its private key.Chilkat Android™ Downloads
// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;
import android.app.Activity;
import com.chilkatsoft.*;
import android.widget.TextView;
import android.os.Bundle;
public class SimpleActivity extends Activity {
private static final String TAG = "Chilkat";
// Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
boolean success = false;
CkMime mime = new CkMime();
success = mime.SetBodyFromPlainText("This message will be signed.");
if (success == false) {
Log.i(TAG, mime.lastErrorText());
return;
}
// Load the signing certificate (which must have access to its private key) from a PFX file.
// The PFX password should come from a secure source rather than being hard-coded.
String pfxPassword = "myPfxPassword";
CkCert cert = new CkCert();
success = cert.LoadPfxFile("qa_data/signer.pfx",pfxPassword);
if (success == false) {
Log.i(TAG, cert.lastErrorText());
return;
}
// Create an S/MIME detached signature. The object becomes a multipart/signed entity with the
// original content and a separate signature part.
success = mime.AddDetachedSignature(cert);
if (success == false) {
Log.i(TAG, mime.lastErrorText());
return;
}
success = mime.SaveMime("qa_output/signed.eml");
if (success == false) {
Log.i(TAG, mime.lastErrorText());
return;
}
Log.i(TAG, "Detached signature added.");
}
static {
System.loadLibrary("chilkat");
// Note: If the incorrect library name is passed to System.loadLibrary,
// then you will see the following error message at application startup:
//"The application <your-application-name> has stopped unexpectedly. Please try again."
}
}