(Android™) IMAP Download and Verify Signed MIME

Downloads the unmodified MIME of a digitally signed email, saves the .p7s signature (and other MIME parts), then loads the email into a Chilkat email object (which unwraps the S/MIME and verifies the signature) and then saves attachments (if the MIME parts were not already saved).

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;
        }

    // Download the 1st email (as MIME) in the Inbox by sequence number.
    CkStringBuilder sbMime = new CkStringBuilder();
    success = imap.FetchSingleAsMimeSb(1,false,sbMime);
    if (success != true) {
        Log.i(TAG, imap.lastErrorText());
        return;
        }

    // Load it into a MIME object and check to see if it is signed
    CkMime mime = new CkMime();
    mime.LoadMimeSb(sbMime);
    boolean alreadySavedParts = false;
    if (mime.ContainsSignedParts() == true) {

        // This will save the .p7s and other parts...
        CkStringArray sa = mime.ExtractPartsToFiles("qa_output");
        if (mime.get_LastMethodSuccess() == true) {
            int numFiles = sa.get_Count();
            int i = 0;
            while (i < numFiles) {
                Log.i(TAG, "Created: " + sa.getString(i));
                i = i + 1;
                }

            alreadySavedParts = true;
            }

        }

    // Load the MIME into an Email object.  This unwraps the security layers and verifies signatures.
    CkEmail email = new CkEmail();
    email.SetFromMimeSb(sbMime);

    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.");
        }

    if (alreadySavedParts != true) {
        email.SaveAllAttachments("qa_output");
        }


  }

  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."
  }
}