add APDUWrapper class and test

app/src/main/java/im/status/applet_installer_test/appletinstaller/APDUWrapper.java

@@ -0,0 +1,43 @@
+package im.status.applet_installer_test.appletinstaller;
+
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.NoSuchPaddingException;
+
+public class APDUWrapper {
+    private byte[] macKeyData;
+
+    public APDUWrapper(byte[] macKeyData) {
+        this.macKeyData = macKeyData;
+    }
+
+    public APDUCommand wrap(APDUCommand cmd) {
+        try {
+            int cla = (cmd.getCla() | 0x04) & 0xff;
+            byte[] data = cmd.getData();
+
+            ByteArrayOutputStream macData = new ByteArrayOutputStream();
+            macData.write(cla);
+            macData.write(cmd.getIns());
+            macData.write(cmd.getP1());
+            macData.write(cmd.getP2());
+            macData.write(data.length + 8);
+            macData.write(data);
+
+            byte[] mac = Crypto.macFull3des(this.macKeyData, Crypto.appendDESPadding(macData.toByteArray()), Crypto.NullBytes8);
+            byte[] newData = new byte[data.length + mac.length];
+            System.arraycopy(data, 0, newData, 0, data.length );
+            System.arraycopy(mac, 0, newData, data.length, mac.length );
+
+            APDUCommand wrapped = new APDUCommand(cla, cmd.getIns(), cmd.getP1(), cmd.getP2(), newData);
+
+            return wrapped;
+        } catch (IOException e) {
+            throw new RuntimeException("error wrapping APDU command.", e);
+        }
+    }
+}

app/src/test/java/im/status/applet_installer_test/appletinstaller/APDUWrapperTest.java

@@ -0,0 +1,22 @@
+package im.status.applet_installer_test.appletinstaller;
+
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.*;
+
+public class APDUWrapperTest {
+    @Test
+    public void wrap() throws IOException {
+        byte[] macKeyData = HexUtils.hexStringToByteArray("904BA06BCE3037710556BE4057D1493C");
+        byte[] data = HexUtils.hexStringToByteArray("7af26ab1ba32b84f");
+
+        APDUCommand cmd = new APDUCommand(0x84, 0x82, 0x01, 0x00, data);
+        APDUWrapper w = new APDUWrapper(macKeyData);
+        APDUCommand wrapped = w.wrap(cmd);
+        byte[] result = wrapped.serialize();
+        String expected = "84820100107AF26AB1BA32B84FFE949381C7BC316C00";
+        assertEquals(expected, HexUtils.byteArrayToHexString(result));
+    }
+}