title: Creating a custom RSA key from String
body: <p>How can I create a custom RSA key from a <code>String</code>? Assume I have a string key which is like a password.</p>
  
  <pre><code>String key = md5("testing");
  </code></pre>
  
  <p>Is there any way to create a private key using the key and derive a public key from the generated private key using RSA?</p>
  
  <p>I am aware it's best practice to use a symmetric key when you have a specific <code>String</code> however I would like to know if it is possible to do this with RSA and how?</p>