title: How to add a password to an existing private key in Java
body: <p>Say I have a previously created private key using openssl, but I've decided not to protect it with a passphrase:</p>
  
  <pre><code>-----BEGIN RSA PRIVATE KEY-----
  BASE64 ENCODED DATA
  -----END RSA PRIVATE KEY-----
  </code></pre>
  
  <p>But then I realised that I want to protect it.</p>
  
  <p>I know how to protect it using openssl, but I have a requirement to do it in Java. Is it possible ?</p>