title: Use "javax.crypto" library in a .JAR file
body: <p>At the beginning of the code of my java application, one class is called to decrypt resources (text files and images) using <code>javax.crypto</code> 
  (These resources were encrypted in the same way).</p>
  
  <p>In Eclipse, the application works well and resources are decrypted. But when I export it to a runnable .JAR file, nothing happens when I try to launch it. I added "jce.jar" library as an "External JAR" in my Build Path, but it still didn't work.</p>
  
  <p>Here is the imports of my "Decrypt" class :</p>
  
  <pre><code>import javax.crypto.Cipher;
  import javax.crypto.CipherOutputStream;
  import javax.crypto.SecretKey;
  import javax.crypto.SecretKeyFactory;
  import javax.crypto.spec.DESKeySpec;
  </code></pre>
  
  <p>I usually use "Proguard" to obfuscate my JAR files, and when I launched it for this project, it showed : </p>
  
  <blockquote>
    <p>-Warning : library class <code>javax.security.auth.kerberos.KerberosKey</code> extends or implements program class <code>javax.crypto.SecretKey</code></p>
    
    <p>-Warning : library class <code>javax.security.auth.kerberos.KeyImpl</code> extends or implements program class <code>javax.crypto.SecretKey</code></p>
    
    <p>-Warning : there were 2 intances of library classes depending on program classes. You must avoid such dependencies, since the program classes will be processed, while the library classes will remain unchanged.</p>
  </blockquote>
  
  <p>What are those classes, and how can I make my runnable JAR works ?</p>
  
  <hr>
  
  <p><strong>EDIT</strong></p>
  
  <p>Okay, I think I found one problem, caused by the way I determine paths of my encrypted and decrypted resources. But I don't know if it's the only problem I have, so I created another post !</p>
  
  <p>(Link : <a href="https://stackoverflow.com/questions/38442653/paths-and-url-for-ressources-in-a-jar-file">Paths and URL for ressources in a .JAR file</a>)</p>