Problems With DES...

Question

Hi. I posted a message previously about DES ands it output but the response didn't help my situation. I want to be able to input 8bytes into the DES and get 8 bytes out. I found another post about inputting 8bytes into the DES and getting 8bytes out, but when I did implement it, it still didn't work.
Here is what my code looks like now:
MAC.java:
===============
// Create key
KeyGenerator vgen = KeyGenerator.getInstance ("DES");
vgen.init (56);
SecretKey key = vgen.generateKey();
// Create encrypter/decrypter class
DesEncrypter encrypter = new DesEncrypter(key);
// Encrypt
String encrypted = encrypter.encrypt("aaaaaaaa");
================================================
DesEncrypter.java
===============
// Create cipher
Cipher ecipher;
// Constructor
DesEncrypter(SecretKey key) {
try {   
ecipher = Cipher.getInstance("DES/OFB8/NoPadding");
// Initial Vector
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
byte bytes[] = new byte[8];
sr.nextBytes(bytes);
ecipher.init(Cipher.ENCRYPT_MODE, key, sr);
// All catch blocks have been purposly left out!
// Encrypt method
public String encrypt(String str) {
try {
// Encode the string into bytes using utf-8
byte[] utf8 = str.getBytes("UTF8");
// Encrypt
byte[] enc = ecipher.doFinal(utf8);
// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);
// All catch blocks have been purposly left out!
================================================
Does anyone know why DES is still outputting 8bytes?

Answer 1

Hi. I posted a message previously about DES ands it
output but the response didn't help my situation. I
want to be able to input 8bytes into the DES and get 8
bytes out. I found another post about inputting 8bytes
into the DES and getting 8bytes out, but when I did
implement it, it still didn't work.
// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);Base64 encoding expands the original by 4/3rds - it's the way Base64 works. So, DES is taking in eight bytes and producing eight bytes, which is expanding to 12 bytes as a result of Base64.
There is no "fix" available - it's the way the algorithms work.
Grant