content: /**
   * Copyright (c) 2018-2019, Mihai Emil Andronache
   * All rights reserved.
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 1)Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   * 2)Redistributions in binary form must reproduce the above copyright notice,
   * this list of conditions and the following disclaimer in the documentation
   * and/or other materials provided with the distribution.
   * 3)Neither the name of docker-java-api nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  package com.amihaiemil.docker;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Base64;
  import java.util.function.Supplier;
  import javax.json.Json;
  
  /**
   * An {@link Auth} holding an Identity token.
   * <p>
   * Identity tokens are obtained after validating your {@link Credentials}
   * with a registry. However, the docker engine is capable of obtaining this
   * token transparently if you just provide {@link Credentials}.
   * <p>
   * {@link IdentityToken} is useful for cases when you have already obtained
   * a token from a previous session and you wish to reuse it.
   *
   * @author George Aristy (george.aristy@gmail.com)
   * @see <a href="https://docs.docker.com/engine/api/v1.35/#section/Authentication">Authentication</a>
   * @see <a href="https://docs.docker.com/registry/spec/auth/token/">Token Authentication Specification</a>
   * @see <a href="https://docs.docker.com/engine/api/v1.35/#operation/SystemAuth">Check auth configuration</a>
   * @version $Id: 6f47263326adf13ef6319144e8acb69f050333b5 $
   * @since 0.0.4
   */
  public final class IdentityToken implements Auth {
      /**
       * Base64-encoded JSON structure holding the identity token. 
       */
      private final Supplier<String> value;
  
      /**
       * Ctor.
       * @param value The token's value
       */
      public IdentityToken(final String value) {
          this.value = () -> Base64.getEncoder().encodeToString(
              Json.createObjectBuilder().add("identitytoken", value)
                  .build().toString()
                  .getBytes(StandardCharsets.UTF_8)
          );
      }
  
      @Override
      public String headerName() {
          return "X-Registry-Auth";
      }
  
      @Override
      public String encoded() {
          return this.value.get();
      }
  }
  