Use a password as a key

Question

hi,
I am working with some code which encrypts data being sent to streams. I currently initialise the instance in the following way.
SecretKey key = KeyGenerator.getInstance("DES").generateKey();
STStreamEncryptor encrypter = new STStreamEncryptor(key);
Here's the constructor for the STStreamEncryptor class......
public STStreamEncryptor(SecretKey key) {
// Create an 8-byte initialization vector
byte[] iv = new byte[]{
(byte)0x8E, 0x12, 0x39, (byte)0x9C,
0x07, 0x72, 0x6F, 0x5A
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
try {
ecipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
dcipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
// CBC requires an initialization vector
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
} catch (java.security.InvalidAlgorithmParameterException e) {
} catch (javax.crypto.NoSuchPaddingException e) {
} catch (java.security.NoSuchAlgorithmException e) {
} catch (java.security.InvalidKeyException e) {
What I want to do is to be able to use a password or phrase as the encryption key instead of generating the key. Can anyone help??
Thanks
Steve

Answer 1

hi,
I've used this class but it throws a number of exceptions. For example when I run the first encryption and decryption on a string it works fine. But when I try to encrypt and decrypt the next string I get an exception, IllegalBlockSizeException: Input length (with padding) not multiple of 8 bytes. Any ideas what the problem is??
Thanks
Steve