content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.celeborn.common.network.sasl;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Base64;
  import java.util.Map;
  
  import javax.security.sasl.Sasl;
  
  import com.google.common.base.Preconditions;
  import com.google.common.collect.ImmutableMap;
  
  import org.apache.celeborn.common.network.sasl.anonymous.AnonymousSaslProvider;
  
  public class SaslUtils {
    static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
  
    /** Sasl Mechanisms */
    public static final String DIGEST_MD5 = "DIGEST-MD5";
  
    public static final String ANONYMOUS = "ANONYMOUS";
  
    /** Quality of protection value that does not include encryption. */
    static final String QOP_AUTH = "auth";
  
    static final String DEFAULT_REALM = "default";
  
    public static final Map<String, String> DEFAULT_SASL_CLIENT_PROPS =
        ImmutableMap.<String, String>builder().put(Sasl.QOP, QOP_AUTH).build();
  
    static final Map<String, String> DEFAULT_SASL_SERVER_PROPS =
        ImmutableMap.<String, String>builder()
            .put(Sasl.SERVER_AUTH, "true")
            .put(Sasl.QOP, QOP_AUTH)
            .build();
  
    /* Encode a byte[] identifier as a Base64-encoded string. */
    static String encodeIdentifier(String identifier) {
      Preconditions.checkNotNull(identifier, "User cannot be null if SASL is enabled");
      return Base64.getEncoder().encodeToString(identifier.getBytes(StandardCharsets.UTF_8));
    }
  
    static String decodeIdentifier(String identifier) {
      Preconditions.checkNotNull(identifier, "User cannot be null if SASL is enabled");
      return new String(
          Base64.getDecoder().decode(identifier.getBytes(StandardCharsets.UTF_8)),
          StandardCharsets.UTF_8);
    }
  
    /** Encode a password as a base64-encoded char[] array. */
    static char[] encodePassword(String password) {
      Preconditions.checkNotNull(password, "Password cannot be null if SASL is enabled");
      return Base64.getEncoder()
          .encodeToString(password.getBytes(StandardCharsets.UTF_8))
          .toCharArray();
    }
  
    static void initializeSaslProviders() {
      AnonymousSaslProvider.initializeIfNeeded();
    }
  }
  