Hey everyone:

I'm trying to use the JCE to encrypt and then decrypt some text. 
Ultimately I want to be able to store an encrypted password in a file 
and retrieve it later to be used in an application. The problem I'm 
having is that the values I'm getting back are not the same values. ie, 
the decrypted byte array is not the same as the original byte array.

Here is my code:

     code:


public class Test {

     public static void main(String[] args) {

         try{

         String keyStr= "This is a test key to use for testing" ;
         DESKeySpec keySpec = new DESKeySpec(keyStr.getBytes());
         SecretKeyFactory keyFac = SecretKeyFactory.getInstance("DES");
         SecretKey sKey = keyFac.generateSecret(keySpec);

         Cipher c1 = Cipher.getInstance("DES/ECB/PKCS5Padding");
         c1.init(Cipher.ENCRYPT_MODE, sKey);

         byte[] bPW = "testPassword".getBytes();
         byte[] ciphertext = c1.doFinal(bPW);

         System.out.println("secret key: " + sKey.getEncoded());
         System.out.println("cipher text: " + ciphertext);

         c1.init(Cipher.DECRYPT_MODE, sKey);
         System.out.println("original text: " + bPW);
         byte[] decipheredtext = c1.doFinal(ciphertext);
         System.out.println("plain text: " + decipheredtext);

     } catch (Exception e){
         System.out.println(e.getMessage());
     }
}
}

I am an absolute newbie as far as encryption so I may be completely off 
in my implementation and/or making a really stupid mistake, so if anyone 
can help I'd appreciate it. My next question would be can I store the 
key in a file and would it be secure? Meaning, I've got all these 
encrypted passwords in a file now I need to get them and decrypt them so 
I'll need to get the key from somewhere. Or would it be better to 
generate the key from a string in the code each time, then the key isn't 
available but the original string would be if they decompile the code. 
Any suggestions, tips, pointers, or shoves in the right direction would 
be great.

Thanks

Dave

You are printing the objects rather than their values. The cipher should 
  construct a new byte array containing the same bytes (a different 
object with the same content).

Additionally, you should specify an encdoing (how to convert characters 
into bytes), e.g. UTF-8. Try something like

....
byte[] bPW = "testPassword".getBytes("UTF-8");
....

System.out.println("original text:" + new String(bPW, "UTF-8");
....
System.out.println("decrypted text:" + new String(decipheredtext, "UTF-8"));

Hope it works now
Jan.

Dave Vick wrote:
> Hey everyone:
> 
> I'm trying to use the JCE to encrypt and then decrypt some text. 
> Ultimately I want to be able to store an encrypted password in a file 
> and retrieve it later to be used in an application. The problem I'm 
> having is that the values I'm getting back are not the same values. ie, 
> the decrypted byte array is not the same as the original byte array.
> 
> Here is my code:
> 
>     code:
> 
> 
> public class Test {
> 
>     public static void main(String[] args) {
> 
>         try{
> 
>         String keyStr= "This is a test key to use for testing" ;
>         DESKeySpec keySpec = new DESKeySpec(keyStr.getBytes());
>         SecretKeyFactory keyFac = SecretKeyFactory.getInstance("DES");
>         SecretKey sKey = keyFac.generateSecret(keySpec);
> 
>         Cipher c1 = Cipher.getInstance("DES/ECB/PKCS5Padding");
>         c1.init(Cipher.ENCRYPT_MODE, sKey);
> 
>         byte[] bPW = "testPassword".getBytes();
>         byte[] ciphertext = c1.doFinal(bPW);
> 
>         System.out.println("secret key: " + sKey.getEncoded());
>         System.out.println("cipher text: " + ciphertext);
> 
>         c1.init(Cipher.DECRYPT_MODE, sKey);
>         System.out.println("original text: " + bPW);
>         byte[] decipheredtext = c1.doFinal(ciphertext);
>         System.out.println("plain text: " + decipheredtext);
> 
>     } catch (Exception e){
>         System.out.println(e.getMessage());
>     }
> }
> }
> 
> I am an absolute newbie as far as encryption so I may be completely off 
> in my implementation and/or making a really stupid mistake, so if anyone 
> can help I'd appreciate it. My next question would be can I store the 
> key in a file and would it be secure? Meaning, I've got all these 
> encrypted passwords in a file now I need to get them and decrypt them so 
> I'll need to get the key from somewhere. Or would it be better to 
> generate the key from a string in the code each time, then the key isn't 
> available but the original string would be if they decompile the code. 
> Any suggestions, tips, pointers, or shoves in the right direction would 
> be great.
> 
> Thanks
> 
> Dave
> 

Jan:

That was perfect, it works great now. Thanks for your help, I was fairly 
sure it was something simple. Thanks also for the encoding tip too.

Dave