fix extended APDUs

The extended APDU feature flag is still helpful to maintain
backwards compatibility in OpenSC.

src/xyz/wendland/javacard/pki/isoapplet/IsoApplet.java

@@ -116,6 +116,7 @@ public class IsoApplet extends Applet implements ExtendedLength {
  private static final byte STATE_OPERATIONAL_DEACTIVATED = (byte) 0x04; // Applet usage is deactivated. (Unused at the moment.)
  private static final byte STATE_TERMINATED = (byte) 0x0C; // Applet usage is terminated. (Unused at the moment.)
 
+ private static final byte API_FEATURE_EXT_APDU = (byte) 0x01;
  private static final byte API_FEATURE_SECURE_RANDOM = (byte) 0x02;
  private static final byte API_FEATURE_ECC = (byte) 0x04;
  private static final byte API_FEATURE_RSA_SHA256_PSS = (byte) 0x08;
@@ -156,7 +157,7 @@ public static void install(byte[] bArray, short bOffset, byte bLength) {
  * \brief Only this class's install method should create the applet object.
  */
  protected IsoApplet() {
- api_features = 0;
+ api_features = API_FEATURE_EXT_APDU;
  pin = new OwnerPIN(PIN_MAX_TRIES, PIN_MAX_LENGTH);
  fs = new IsoFileSystem();