Android™

Get the SMTP or POP3 Server's TLS Certificate

Demonstrates the Chilkat MailMan.GetServerCert method, which gets the digital certificate presented by the SMTP or POP3 server for the current SSL/TLS connection and stores it in a Cert object. Pass true for the SMTP server's certificate or false for the POP3 server's. This example connects to the SMTP server and prints the certificate's subject and issuer.

Background: During a TLS handshake the server presents a certificate proving its identity, and the client validates it against trusted authorities. Retrieving that certificate lets you inspect it yourself — checking the subject, issuer, or expiration for auditing, logging, or certificate-pinning style checks. It must be called while a TLS connection is established, since the certificate belongs to that specific session.

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Android™

// 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;

    //  Demonstrates the MailMan.GetServerCert method, which gets the digital certificate
    //  presented by the SMTP or POP3 server for the current SSL/TLS connection.  Pass true for
    //  the SMTP server's certificate, or false for the POP3 server's certificate.

    CkMailMan mailman = new CkMailMan();

    //  Configure the SMTP server connection.
    mailman.put_SmtpHost("smtp.example.com");
    mailman.put_SmtpPort(465);
    mailman.put_SmtpSsl(true);
    mailman.put_SmtpUsername("user@example.com");
    mailman.put_SmtpPassword("myPassword");

    //  Establish the TLS connection.
    success = mailman.SmtpConnect();
    if (success == false) {
        Log.i(TAG, mailman.lastErrorText());
        return;
        }

    //  Get the certificate the SMTP server presented (useSmtp = true).
    CkCert cert = new CkCert();
    success = mailman.GetServerCert(true,cert);
    if (success == false) {
        Log.i(TAG, mailman.lastErrorText());
        return;
        }

    Log.i(TAG, "Server certificate subject (CN): " + cert.subjectCN());
    Log.i(TAG, "Issued by: " + cert.issuerCN());

    success = mailman.CloseSmtpConnection();
    if (success == false) {
        Log.i(TAG, mailman.lastErrorText());
        return;
        }


  }

  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."
  }
}