/**
    *
    * 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.hadoop.hbase.security;
  
  import org.apache.commons.codec.binary.Base64;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  import java.util.Map;
  import java.util.TreeMap;
  
  import javax.security.sasl.Sasl;
  
  import org.apache.commons.codec.binary.Base64;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  @InterfaceAudience.Private
  public class SaslUtil {
    private static final Log log = LogFactory.getLog(SaslUtil.class);
    public static final String SASL_DEFAULT_REALM = "default";
    public static final Map<String, String> SASL_PROPS =
        new TreeMap<String, String>();
    public static final int SWITCH_TO_SIMPLE_AUTH = -88;
  
    public static enum QualityOfProtection {
      AUTHENTICATION("auth"),
      INTEGRITY("auth-int"),
      PRIVACY("auth-conf");
  
      public final String saslQop;
  
      private QualityOfProtection(String saslQop) {
        this.saslQop = saslQop;
      }
  
      public String getSaslQop() {
        return saslQop;
      }
    }
  
    /** Splitting fully qualified Kerberos name into parts */
    public static String[] splitKerberosName(String fullName) {
      return fullName.split("[/@]");
    }
  
    static String encodeIdentifier(byte[] identifier) {
      return new String(Base64.encodeBase64(identifier));
    }
  
    static byte[] decodeIdentifier(String identifier) {
      return Base64.decodeBase64(identifier.getBytes());
    }
  
    static char[] encodePassword(byte[] password) {
      return new String(Base64.encodeBase64(password)).toCharArray();
    }
  
    /**
     * Returns {@link org.apache.hadoop.hbase.security.SaslUtil.QualityOfProtection}
     * corresponding to the given {@code stringQop} value. Returns null if value is
     * invalid.
     */
    public static QualityOfProtection getQop(String stringQop) {
      QualityOfProtection qop = null;
      if (QualityOfProtection.AUTHENTICATION.name().toLowerCase().equals(stringQop)
          || QualityOfProtection.AUTHENTICATION.saslQop.equals(stringQop)) {
        qop = QualityOfProtection.AUTHENTICATION;
      } else if (QualityOfProtection.INTEGRITY.name().toLowerCase().equals(stringQop)
          || QualityOfProtection.INTEGRITY.saslQop.equals(stringQop)) {
        qop = QualityOfProtection.INTEGRITY;
      } else if (QualityOfProtection.PRIVACY.name().toLowerCase().equals(stringQop)
          || QualityOfProtection.PRIVACY.saslQop.equals(stringQop)) {
        qop = QualityOfProtection.PRIVACY;
      }
      if (qop == null) {
        throw new IllegalArgumentException("Invalid qop: " +  stringQop
            + ". It must be one of 'authentication', 'integrity', 'privacy'.");
      }
      if (QualityOfProtection.AUTHENTICATION.saslQop.equals(stringQop)
          || QualityOfProtection.INTEGRITY.saslQop.equals(stringQop)
          || QualityOfProtection.PRIVACY.saslQop.equals(stringQop)) {
        log.warn("Use authentication/integrity/privacy as value for rpc protection "
           + "configurations instead of auth/auth-int/auth-conf.");
     }
     return qop;
   }
 
   static void initSaslProperties(String rpcProtection) {
     QualityOfProtection saslQOP = getQop(rpcProtection);
     if (saslQOP == null) {
       saslQOP = QualityOfProtection.AUTHENTICATION;
     }
     SaslUtil.SASL_PROPS.put(Sasl.QOP, saslQOP.getSaslQop());
     SaslUtil.SASL_PROPS.put(Sasl.SERVER_AUTH, "true");
   }
 }