title: How to Convert a byte array to DSA private key?
body: <p>As a part of project implementation, i have done the following things: 
  1. Generete DSA keys
  2. Encrypt the private key using AES
  3. Save into the file
  4. Open the file and read the encrypted private key
  5. I tried to convert the read value into primary key format but error comes here.
  I am attaching the code of the above steps here : </p>
  
  <pre><code>public class Pgm {
  public static void main(String[] args) { 
  try {
              KeyPairGenerator dsa =  KeyPairGenerator.getInstance("DSA");
              SecureRandom random = new SecureRandom();
              dsa.initialize(1024, random);
              KeyPair keypair = dsa.generateKeyPair();
              PrivateKey privateKey = (PrivateKey) keypair.getPrivate();
              byte[] key = "�u���1Ù�iw&amp;a".getBytes();
              Key aesKey = new SecretKeySpec(key, "AES");
              Cipher cipher = Cipher.getInstance("AES");
              String currentDir = System.getProperty("user.dir"); 
              // encrypt the text
              cipher.init(Cipher.ENCRYPT_MODE, aesKey);
              byte[] abc = privateKey.getEncoded();
  
              byte[] encrypted = cipher.doFinal(abc);
              // System.out.println("len="+encrypted.length());
              File dir=new File(currentDir);
              File private_file=new File(dir,"privatekey.txt");
              if(!private_file.exists()){
                  private_file.createNewFile();
              }
              FileOutputStream fileos = new FileOutputStream(private_file); 
              ObjectOutputStream objectos = new ObjectOutputStream(fileos);
              objectos.writeObject(encrypted);
              objectos.close();
              fileos.close();
  
              File file_private = new File(dir,"privatekey.txt");
              FileInputStream fileo = new FileInputStream(file_private); 
              ObjectInputStream objos = new ObjectInputStream(fileo);
              Object obj = objos.readObject();
              byte[] encrypted1= (byte[] )obj;
              cipher.init(Cipher.DECRYPT_MODE, aesKey);
              String decrypted = new String(cipher.doFinal(encrypted1));
              if (decrypted.equals(new String(abc)))
                 System.out.println("true");
              else
                 System.out.println("false");
              Signature tosign = Signature.getInstance("DSA");
              byte[] val =  decrypted.getBytes();
              PrivateKey privatekey1 = (PrivateKey)val;
              tosign.initSign(privatekey1);   
  
        }
        catch(Exception e)
        {
              e.printStackTrace();
        }
    }
  </code></pre>
  
  <p>}</p>
  
  <p>'
       <code>PrivateKey privatekey1 = (PrivateKey)val;</code></p>
  
  <p>shows the error as  inconvertible types </p>