content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.security.authentication.plain;
  
  import java.io.IOException;
  import javax.security.auth.callback.Callback;
  import javax.security.auth.callback.CallbackHandler;
  import javax.security.auth.callback.NameCallback;
  import javax.security.auth.callback.PasswordCallback;
  import javax.security.auth.callback.UnsupportedCallbackException;
  
  /**
   * A client side callback to put application provided username/password into SASL transport.
   */
  public final class PlainSaslClientCallbackHandler implements CallbackHandler {
  
    private final String mUserName;
    private final String mPassword;
  
    /**
     * Constructs a new client side callback.
     *
     * @param userName the name of the user
     * @param password the password
     */
    public PlainSaslClientCallbackHandler(String userName, String password) {
      mUserName = userName;
      mPassword = password;
    }
  
    @Override
    public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
      for (Callback callback : callbacks) {
        if (callback instanceof NameCallback) {
          NameCallback nameCallback = (NameCallback) callback;
          nameCallback.setName(mUserName);
        } else if (callback instanceof PasswordCallback) {
          PasswordCallback passCallback = (PasswordCallback) callback;
          passCallback.setPassword(mPassword == null ? null : mPassword.toCharArray());
        } else {
          Class<?> callbackClass = (callback == null) ? null : callback.getClass();
          throw new UnsupportedCallbackException(callback, callbackClass + " is unsupported.");
        }
      }
    }
  }
  