/*

• Copyright (C) 2018-2021 Confidential Technologies GmbH

• You can purchase a commercial license at https://hwsecurity.dev.

• Buying such a license is mandatory as soon as you develop commercial

• activities involving this program without disclosing the source code

• of your own applications.

• This program is free software: you can redistribute it and/or modify

• it under the terms of the GNU General Public License as published by

• the Free Software Foundation, either version 3 of the License, or

• (at your option) any later version.

• This program is distributed in the hope that it will be useful,

• but WITHOUT ANY WARRANTY; without even the implied warranty of

• MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

• GNU General Public License for more details.

• You should have received a copy of the GNU General Public License

• along with this program. If not, see <http://www.gnu.org/licenses/ .>
  */

package de.cotech.hw;

import java.io.IOException;

import androidx.annotation.AnyThread;
import androidx.annotation.WorkerThread;

import de.cotech.hw.internal.transport.SecurityKeyInfo.TransportType;
import de.cotech.hw.internal.transport.Transport;

/**

• An abstract connected Security Key.

• Concrete instances of this class, such as FidoSecurityKey, PivSecurityKey, or OpenPgpSecurityKey,

• offer methods to interact with the connected Security Key and applet.

• @see SecurityKeyCallback

• @see SecurityKeyManager#registerCallback
  */
  @SuppressWarnings({ "WeakerAccess", "unused" }) // public API
  public abstract class SecurityKey {
  protected final SecurityKeyManagerConfig config;
  protected final Transport transport;

  public SecurityKey(SecurityKeyManagerConfig config, Transport transport) {
  this.config = config;
  this.transport = transport;
  }

  /**

  • This method checks if communication with the security key is still available by sending a no-op ping command.

  • <p>

  • This is useful especially for security keys connected via NFC, since the connection status as tracked by the

  • operating system sometimes has a delay of up to two seconds.

  • <p>

  • This method directly performs IO with the security token, and should therefore not be called on the UI thread.
    */
    @WorkerThread
    public void checkConnectionOrThrow() throws IOException {
    if (!transport.ping()) {
    throw new IOException("Transport no longer connected!");
    }
    }

  /**

  • @return true if the underlying transport is NFC.
    */
    @AnyThread
    public boolean isTransportNfc() {
    return transport.getTransportType() == TransportType.NFC;
    }

  /**

  • @return true if the underlying transport is USB.
    */
    @AnyThread
    public boolean isTransportUsb() {
    return transport.getTransportType() == TransportType.USB_CCID || transport.getTransportType() == TransportType.USB_CTAPHID;
    }

  /**

  • @return true if the underlying transport is persistently connected.
    */
    @AnyThread
    public boolean isPersistentlyConnected() {
    return transport.isPersistentConnectionAllowed();
    }

  /**

  • Releases the Security Key as well as the underlying transport.
    */
    public void release() {
    transport.release();
    }
    }