Re: Simple encryption/decryption

From:
Mark Space <markspace@sbc.global.net>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 23 Mar 2009 18:03:57 -0700
Message-ID:
<8kWxl.2697$im1.2275@nlpi061.nbdc.sbc.com>
Arne Vajh?j wrote:

Mark Space wrote:

I'm not seeing a good answer to this. In particular, the
SecretKeyFactory.getInstance( "ARCFOUR" ) method returns an error. I
don't see a simple way to use RC4 without this call succeeding.
Anyone got a solution?


    private Cipher rc4;
    private SecretKey rc4key;
    public RC4(String key) {
        try {
            rc4 = Cipher.getInstance("RC4");
            rc4key = new SecretKeySpec(key.getBytes(), "RC4");
        } catch(Exception e) {
            e.printStackTrace();
        }
    }

works fine for me.


Thanks for that, I'll play around with it. I read the docs and thought
I was supposed to use a SecretKeyFactory. The SecretKeySpec class
looked like something else (a "specification" for the key).

Just for reference, the following fails on line 34 (marked):

public class Encryption {

     Cipher c;
     public Encryption( String password )
             throws NoSuchAlgorithmException,
             NoSuchPaddingException,
             InvalidKeySpecException,
             InvalidKeyException
     {
         c = Cipher.getInstance( "RC4" );
         char[] passChars = new char[password.length()];
         password.getChars( 0, passChars.length, passChars, 0 );
         // line 34 below
         SecretKeyFactory skf = SecretKeyFactory.getInstance( "ARCFOUR" );
         SecretKey sk = skf.generateSecret( new PBEKeySpec( passChars ) );
         c.init( Cipher.ENCRYPT_MODE, sk );
     }

     public static void main ( String... args )
             throws Exception
     {
         System.out.println( new Encryption("password1234") );
     }
}

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