/*
    * 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.shardingsphere.db.protocol.postgresql.packet.handshake.authentication;
  
  import lombok.RequiredArgsConstructor;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.identifier.PostgreSQLIdentifierPacket;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.identifier.PostgreSQLIdentifierTag;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.identifier.PostgreSQLMessagePacketType;
  import org.apache.shardingsphere.db.protocol.postgresql.payload.PostgreSQLPacketPayload;
  
  /**
   * MD5 password authentication (backend) packet for PostgreSQL.
   */
  @RequiredArgsConstructor
  public final class PostgreSQLMD5PasswordAuthenticationPacket extends PostgreSQLIdentifierPacket {
      
      private static final int AUTH_REQ_MD5 = 5;
      
      private final byte[] md5Salt;
      
      @Override
      protected void write(final PostgreSQLPacketPayload payload) {
          payload.writeInt4(AUTH_REQ_MD5);
          payload.writeBytes(md5Salt);
      }
      
      @Override
      public PostgreSQLIdentifierTag getIdentifier() {
          return PostgreSQLMessagePacketType.AUTHENTICATION_REQUEST;
      }
  }