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/*
Wireless Java 2nd edition
Jonathan Knudsen
Publisher: Apress
ISBN: 1590590775
*/
import java.io.*;
import java.util.Random;
import javax.microedition.io.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.SHA1Digest;
public class PasswordMIDlet extends MIDlet implements CommandListener, Runnable {
private Display mDisplay;
private Form mForm;
private TextField mUserField, mPasswordField;
private Random mRandom;
public void startApp() {
mDisplay = Display.getDisplay(this);
mRandom = new Random(System.currentTimeMillis());
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);
// Create the GET URL. The hex encoded message digest value is
// included as a parameter.
URLBuilder ub = new URLBuilder(getAppProperty("PasswordMIDlet-URL"));
ub.addParameter("user", user);
ub.addParameter("timestamp",
new String(HexCodec.bytesToHex(timestampBytes)));
ub.addParameter("random",
new String(HexCodec.bytesToHex(randomBytes)));
ub.addParameter("digest",
new String(HexCodec.bytesToHex(digestValue)));
String url = ub.toString();
try {
// Query the server and retrieve the response.
HttpConnection hc = (HttpConnection)Connector.open(url);
InputStream in = hc.openInputStream();
int length = (int)hc.getLength();
byte[] raw = new byte[length];
in.read(raw);
String response = new String(raw);
Alert a = new Alert("Response", response, null, null);
a.setTimeout(Alert.FOREVER);
mDisplay.setCurrent(a, mForm);
in.close();
hc.close();
}
catch (IOException ioe) {
Alert a = new Alert("Exception", ioe.toString(), null, null);
a.setTimeout(Alert.FOREVER);
mDisplay.setCurrent(a, mForm);
}
}
private byte[] getBytes(long x) {
byte[] bytes = new byte[8];
for (int i = 0; i < 8; i++)
bytes[i] = (byte)(x >> ((7 - i) * 8));
return bytes;
}
public void pauseApp() { }
public void destroyApp(boolean unconditional) { }
}
class URLBuilder {
private StringBuffer mBuffer;
private boolean mHasParameters;
public URLBuilder(String base) {
mBuffer = new StringBuffer(base);
mHasParameters = false;
}
public void addParameter(String name, String value) {
// Append a separator.
if (mHasParameters == false) {
mBuffer.append('?');
mHasParameters = true;
}
else
mBuffer.append('&');
// Now tack on the name and value pair. These should
// really be URL encoded (see java.net.URLEncoder in
// J2SE) but this class appends the name and value
// as is, for simplicity. Names or values with spaces
// or other special characters will not work correctly.
mBuffer.append(name);
mBuffer.append('=');
mBuffer.append(value);
}
public String toString() {
return mBuffer.toString();
}
}
class HexCodec {
private static final char[] kDigits = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f'
} ;
public static char[] bytesToHex(byte[] raw) {
int length = raw.length;
char[] hex = new char[length * 2];
for (int i = 0; i < length; i++) {
int value = (raw[i] + 256) % 256;
int highIndex = value >> 4;
int lowIndex = value & 0x0f;
hex[i * 2 + 0] = kDigits[highIndex];
hex[i * 2 + 1] = kDigits[lowIndex];
}
return hex;
}
public static byte[] hexToBytes(char[] hex) {
int length = hex.length / 2;
byte[] raw = new byte[length];
for (int i = 0; i < length; i++) {
int high = Character.digit(hex[i * 2], 16);
int low = Character.digit(hex[i * 2 + 1], 16);
int value = (high << 4) | low;
if (value > 127) value -= 256;
raw[i] = (byte)value;
}
return raw;
}
public static byte[] hexToBytes(String hex) {
return hexToBytes(hex.toCharArray());
}
}
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