(Android™) IMAP Download and Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkImap imap = new CkImap();

    // Connect to an IMAP server.
    // Use TLS
    imap.put_Ssl(true);
    imap.put_Port(993);
    boolean success = imap.Connect("imap.someMailServer.com");
    if (success != true) {
        Log.i(TAG, imap.lastErrorText());
        return;
        }

    success = imap.Login("myLogin","myPassword");
    if (success != true) {
        Log.i(TAG, imap.lastErrorText());
        return;
        }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox");
    if (success != true) {
        Log.i(TAG, imap.lastErrorText());
        return;
        }

    // We can choose to fetch UIDs or sequence numbers.
    boolean fetchUids = true;

    // Get the message IDs of all the emails in the mailbox
    CkMessageSet messageSet = imap.Search("ALL",fetchUids);
    if (imap.get_LastMethodSuccess() != true) {
        Log.i(TAG, imap.lastErrorText());
        return;
        }

    // Scan for emails with attachments, and save the attachments
    // to a sub-directory.
    int i = 0;
    while (i < messageSet.get_Count()) {

        String uid = messageSet.GetId(i);
        Log.i(TAG, "uid: " + uid);

        CkEmail email = imap.FetchSingle(uid,true);

        // The security layers of signed and/or encrypted emails
        // are automatically "unwrapped" when loaded into
        // a Chilkat email object.
        // An application only needs to check to see if an email
        // was received signed or encrypted, and then examine
        // the success/failure.  For example:
        if (email.get_ReceivedSigned() == true) {

            Log.i(TAG, "This email was signed.");

            // Check to see if the signatures were verified.
            if (email.get_SignaturesValid() == true) {
                Log.i(TAG, "Digital signature(s) verified.");

                Log.i(TAG, "Signer: " + email.signedBy());

                // The certificate used for signing may be obtained
                // by calling email.GetSignedByCert.
                CkCert cert = email.GetSignedByCert();
                if (email.get_LastMethodSuccess() != true) {
                    Log.i(TAG, "Failed to get signing certificate object.");
                    }
                else {
                    Log.i(TAG, "Signing cert: " + cert.subjectCN());

                    }

                }
            else {
                Log.i(TAG, "Digital signature verification failed.");
                }

            }

        i = i + 1;
        }

    // Disconnect from the IMAP server.
    success = imap.Disconnect();


  }

  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."
  }
}