SIM Card Programming

1package com.example.stk;
2
3import javacard.framework.*;
4import sim.toolkit.*;
5
6public class MenuApplet extends Applet implements ToolkitInterface, ToolkitConstants {
7    // Menu items
8    private static final byte ITEM_BALANCE = (byte) 1;
9    private static final byte ITEM_TRANSFER = (byte) 2;
10    private static final byte ITEM_SETTINGS = (byte) 3;
11    
12    // Menu text
13    private static final String MENU_TITLE = "Banking Menu";
14    private static final String[] MENU_ITEMS = {
15        "Check Balance",
16        "Transfer Money",
17        "Settings"
18    };
19    
20    // ToolkitRegistry reference
21    private ToolkitRegistry reg;
22    
23    private MenuApplet() {
24        // Register with the applet
25        register();
26        
27        // Get the toolkit registry
28        reg = ToolkitRegistry.getEntry();
29        
30        // Register for the MENU event
31        reg.setEvent(EVENT_MENU_SELECTION);
32        
33        // Initialize the menu
34        initializeMenu();
35    }
36    
37    public static void install(byte[] bArray, short bOffset, byte bLength) {
38        new MenuApplet();
39    }
40    
41    private void initializeMenu() {
42        // Create the main menu
43        Menu menu = new Menu(MENU_TITLE, (short) 0, (short) MENU_TITLE.length(), (byte) 0);
44        
45        // Add menu items
46        for (byte i = 0; i < MENU_ITEMS.length; i++) {
47            menu.appendItem(MENU_ITEMS[i], (short) 0, (short) MENU_ITEMS[i].length(), (byte) (i + 1), false);
48        }
49        
50        // Register the menu
51        reg.registerMenu(menu);
52    }
53    
54    public void process(APDU apdu) throws ISOException {
55        // Process regular APDUs if needed
56        if (selectingApplet()) {
57            return;
58        }
59        
60        // Other APDU processing...
61    }
62    
63    public void processToolkit(byte event) throws ToolkitException {
64        // Handle menu selection event
65        if (event == EVENT_MENU_SELECTION) {
66            // Get the selected item
67            byte selectedItem = reg.getMenuItemIdentifier();
68            
69            // Handle the selection
70            switch (selectedItem) {
71                case ITEM_BALANCE:
72                    showBalance();
73                    break;
74                case ITEM_TRANSFER:
75                    showTransferMenu();
76                    break;
77                case ITEM_SETTINGS:
78                    showSettings();
79                    break;
80            }
81        }
82    }
83    
84    private void showBalance() {
85        // Create a display text proactive command
86        ProactiveHandler handler = ProactiveHandler.getTheHandler();
87        handler.init(PRO_CMD_DISPLAY_TEXT, (byte) 0x81, DEV_ID_DISPLAY);
88        handler.appendTLV(TAG_TEXT_STRING, (byte) 0x04, "Your balance: $1,250.75");
89        handler.send();
90    }
91    
92    private void showTransferMenu() {
93        // Implementation for transfer menu
94        // ...
95    }
96    
97    private void showSettings() {
98        // Implementation for settings
99        // ...
100    }
101}

1// OTA Message Structure
2+------------------+
3| SMS Header       | Standard SMS header
4+------------------+
5| Command Packet   | Contains the actual OTA command
6|                  |
7| +---------------+|
8| | Security Header|| Contains security parameters
9| +---------------+|
10| | Command Header || Identifies the command type
11| +---------------+|
12| | Command Data  || The actual command data
13| +---------------+|
14+------------------+
15
16// Example of a Remote File Management command
17// (Simplified representation)
18D0 // Command Packet Tag
1981 // Length
2002 // Command Header: Remote File Management
21A4 00 00 02 3F 00 // SELECT command for MF
22B0 00 00 0A // READ BINARY command for 10 bytes