Protecting Network Data - Beginning J2ME: From Novice to Professional - page 343

if (mForm == null) {
mForm = new Form("Login");
mUserField = new TextField("Name", "jonathan", 32, 0);
mPasswordField = new TextField("Password", "happy8", 32, 0);
mForm.append(mUserField);
mForm.append(mPasswordField);
mForm.addCommand(new Command("Exit", Command.EXIT, 0));
mForm.addCommand(new Command("Login", Command.SCREEN, 0));
mForm.setCommandListener(this);
}
mDisplay.setCurrent(mForm);
}
public void commandAction(Command c, Displayable s) {
if (c.getCommandType() == Command.EXIT) notifyDestroyed();
else {
Form waitForm = new Form("Connecting...");
mDisplay.setCurrent(waitForm);
Thread t = new Thread(this);
t.start();
}
}
public void run() {
// Gather the values we'll need.
long timestamp = System.currentTimeMillis();
long randomNumber = mRandom.nextLong();
String user = mUserField.getString();
byte[] userBytes = user.getBytes();
byte[] timestampBytes = getBytes(timestamp);
byte[] randomBytes = getBytes(randomNumber);
String password = mPasswordField.getString();
byte[] passwordBytes = password.getBytes();
// Create the message digest.
Digest digest = new SHA1Digest();
// Calculate the digest value.
digest.update(userBytes, 0, userBytes.length);
digest.update(timestampBytes, 0, timestampBytes.length);
digest.update(randomBytes, 0, randomBytes.length);
digest.update(passwordBytes, 0, passwordBytes.length);
byte[] digestValue = new byte[digest.getDigestSize()];
digest.doFinal(digestValue, 0);