Security and DES keys

[Jason Bock]

I'm trying to generate a DES key, but the key length I get back is 8 and I
thought it should be 56. Here's my code:

import java.io.*;
import java.util.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;

// assume pwd is equal to something like "javapassword"
MessageDigest messagedigest = MessageDigest.getInstance("SHA");
System.out.println("MessageDigest algorithm made via SHA algorithm...");
messagedigest.update(pwd.getBytes());
String msgDigest = new String(messagedigest.digest());
System.out.println("Message digest complete, length is " + (new
Integer(msgDigest.getBytes().length)) );

DESKeySpec dks = new DESKeySpec(msgDigest.getBytes());
System.out.println("DESKeySpec complete...");
SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
System.out.println("SecretKeyFactory complete...");
SecretKey key = skf.generateSecret(dks);
System.out.println("Key generation is complete, length is " + (new
Integer(key.getEncoded().length)) );

What happens is that the SHA hash works (I have to duplicate this in Windows
via the CryptoAPI and I've verified that the two hash values are equal).
However, the key length always ends up being 8, when the documentation
states that key lengths should be 56. What ends up happening is that the
first 8 bytes match between my Windows and Java code, but after that nothing
matches.

How do I remedy this in my Java code?

Thanks,

Jason Bock

[Jason Bock]

Shoot me. 8 bytes = 56 bits. Argh!

Jason

"Jason Bock" <jrbock@execpc.com> wrote in message
news:38cd59d6$1@news.devx.com...
> I'm trying to generate a DES key, but the key length I get back is 8 and I
> thought it should be 56. Here's my code:
>
> import java.io.*;
> import java.util.*;
> import java.security.*;
> import javax.crypto.*;
> import javax.crypto.spec.*;
>
> // assume pwd is equal to something like "javapassword"
> MessageDigest messagedigest = MessageDigest.getInstance("SHA");
> System.out.println("MessageDigest algorithm made via SHA algorithm...");
> messagedigest.update(pwd.getBytes());
> String msgDigest = new String(messagedigest.digest());
> System.out.println("Message digest complete, length is " + (new
> Integer(msgDigest.getBytes().length)) );
>
> DESKeySpec dks = new DESKeySpec(msgDigest.getBytes());
> System.out.println("DESKeySpec complete...");
> SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
> System.out.println("SecretKeyFactory complete...");
> SecretKey key = skf.generateSecret(dks);
> System.out.println("Key generation is complete, length is " + (new
> Integer(key.getEncoded().length)) );
>
> What happens is that the SHA hash works (I have to duplicate this in
Windows
> via the CryptoAPI and I've verified that the two hash values are equal).
> However, the key length always ends up being 8, when the documentation
> states that key lengths should be 56. What ends up happening is that the
> first 8 bytes match between my Windows and Java code, but after that
nothing
> matches.
>
> How do I remedy this in my Java code?
>
> Thanks,
>
> Jason Bock
>
>

[Jason Bock]

Jason Bock <jrbock@execpc.com> wrote in message
news:38cd5e00@news.devx.com...
> Shoot me. 8 bytes = 56 bits. Argh!
>
> Jason

Shoot me again! I meant that the 8 bytes in the key = 64 bits, but the key
is the 56 bit key.