Add IDENTIFY CARD (#24)

* ident applet support

* add identify card command

* fix certificate class

* make sure private key is 32 bytes

* don't remove TLV header from signature

* fix typo

* use secure channel if open

lib/src/main/java/im/status/keycard/applet/KeycardCommandSet.java

@@ -20,6 +20,7 @@ public class KeycardCommandSet {
   static final byte INS_INIT = (byte) 0xFE;
   static final byte INS_GET_STATUS = (byte) 0xF2;
   static final byte INS_SET_NDEF = (byte) 0xF3;
+  static final byte INS_IDENTIFY_CARD = (byte) 0x14;
   static final byte INS_VERIFY_PIN = (byte) 0x20;
   static final byte INS_CHANGE_PIN = (byte) 0x21;
   static final byte INS_UNBLOCK_PIN = (byte) 0x22;
@@ -269,6 +270,18 @@ public class KeycardCommandSet {
     secureChannel.unpairOthers(apduChannel);
   }
 
+  /**
+   * Sends an IDENTIFY CARD APDU. The challenge is sent as APDU data as-is. It must be 32 bytes long
+   *
+   * @param challenge the data of the APDU
+   * @return the raw card response
+   * @throws IOException communication error
+   */
+  public APDUResponse identifyCard(byte[] challenge) throws IOException {
+    APDUCommand identifyCard = secureChannel.protectedCommand(0x80, INS_IDENTIFY_CARD, 0, 0, challenge);
+    return secureChannel.transmit(apduChannel, identifyCard);
+  }
+
   /**
    * Sends a GET STATUS APDU. The info byte is the P1 parameter of the command, valid constants are defined in the applet
    * class itself.