package im.status.keycard.io;

import java.io.IOException;

/**
 * A channel to transcieve ISO7816-4 APDUs.
 */
public interface CardChannel {
  /**
   * Sends the given C-APDU and returns an R-APDU.
   *
   * @param cmd the command to send
   * @return the card response
   * @throws IOException communication error
   */
  APDUResponse send(APDUCommand cmd) throws IOException;

  /**
   * True if connected, false otherwise
   * @return true if connected, false otherwise
   */
  boolean isConnected();

  /**
   * Returns the iteration count for deriving the pairing key from the pairing password. The default is 50000 and is
   * should only be changed for devices where the PBKDF2 is calculated on-board and the resource do not permit a
   * high iteration count. If a lower count is used other security mechanism should be used to prevent brute force
   * attacks.
   *
   * @return the iteration count
   */
  default int pairingPasswordPBKDF2IterationCount() {
    return 50000;
  }
}