Java Mail S/MIME Transport

When this library is added to a project you may configure a Java Mail session to use the smtp+smime or smtps+smime protocol to have the transport sign outgoing mail with a mail certificate stored in a Java keystore (JKS) file.

Installation

From Maven

Add the following as a dependency in your pom.xml

<dependency>
    <groupId>edu.iu.uits</groupId>
    <artifactId>javamail-smime-transport</artifactId>
    <version><!-- latest version --></version>
</dependency>

You can find the latest version in Maven Central.

Configuration

The following properties need to be set to configure the Java mail session

Property	Description
mail.transport.protocol	Special protocol to use: smtp+smime or smtps+smime
mail.keystore.file	Keystore file containing certificate
mail.keystore.password	Password for keystore file
mail.keystore.<email address>.password	Password for email address alias in keystore

If you omit the mail.keystore.<email address>.password configuration, the process will look for an alias in the keystore that matches the email "from" address and use the keystore password

Examples

Java Mail

// example class
class Mailer {
    
    Session mailSession;
    
    public Mailer(String smtpHost, String smtpPort, String username, String password) {
        properties.put("mail.transport.protocol", "smtp+smime");
        properties.put("mail.smtp+smime.host",  smtpHost);
        properties.put("mail.smtp+smime.port", smtpPort);
        properties.put("mail.smtp+smime.auth", "true");
        properties.put("mail.smtp+smime.starttls.enable", "true");
        
        mailSession = Session.getInstance(properties, new javax.mail.Authenticator() {
          protected PasswordAuthentication getPasswordAuthentication() {
             return new PasswordAuthentication(username, password);
          }
       });        
    }
    
    public void mail(String fromAddress, String toAddress, String subject, String text) {
        MimeMessage message = new MimeMessage(mailSession);
        message.setFrom(new InternetAddress(fromAddress));
        message.addRecipient(Message.RecipientType.TO, new InternetAddress(toAddress));
        message.setSubject(subject);
        message.setText(text);
        Transport.send(message);        
    }
}

Spring Mail

# application.yml
spring.mail:
  protocol: smtp+smime
  host: <smtp-host>
  port: <smtp-port>
  properties.mail:
    keystore:
      file: <path-to-keystore>
    smtp+smime.starttls.enable: true

class Mailer {
    
    @Autowired
    private MailSender mailSender;
    
    public void mail(String fromAddress, String toAddress, String subject, String text) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(fromAddress);
        message.setTo(toAddress);
        message.setSubject(subject);
        message.setText(text);
        mailSender.send(message);        
    }    
}

Testing Configuration

Unit Tests

The unit tests (under src/test can run without configuration).

Integration Tests

The integration tests (under src/it) require the following configuration:

A properties file whose default location is /opt/j2ee/security/kr//opt/j2ee/security/kr/rice-keystore.properties. This location can be overridden with a KEYSTORE_PROPERTY_FILE_PATH environment variable.

The properties file should have keystore.file and keystore.password entries as well as at least one email address mapped to its certificate password. For example:

keystore.file=/path/to/keystore.jks
keystore.password=73cur3P@ssw0rd
foo@example.com=p@ssw0rd4al1as

Adding license headers

Each source file in this project needs to include the standard license header at the top of the file. This header can be added automatically by running the following:

mvn license:update-file-header

When a pull request is submitted the license headers will be verified and we will not be able to merge pull requests with files which lack this header.