/*
    * 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.token;
  
  import javax.crypto.SecretKey;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  import java.util.Arrays;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.io.WritableUtils;
  
  /**
   * Represents a secret key used for signing and verifying authentication tokens
   * by {@link AuthenticationTokenSecretManager}.
   */
  @InterfaceAudience.Private
  public class AuthenticationKey implements Writable {
    private int id;
    private long expirationDate;
    private SecretKey secret;
  
    public AuthenticationKey() {
      // for Writable
    }
  
    public AuthenticationKey(int keyId, long expirationDate, SecretKey key) {
      this.id = keyId;
      this.expirationDate = expirationDate;
      this.secret = key;
    }
  
    public int getKeyId() {
      return id;
    }
  
    public long getExpiration() {
      return expirationDate;
    }
  
    public void setExpiration(long timestamp) {
      expirationDate = timestamp;
    }
  
    SecretKey getKey() {
      return secret;
    }
  
    @Override
    public int hashCode() {
      int result = id;
      result = 31 * result + (int) (expirationDate ^ (expirationDate >>> 32));
      result = 31 * result + ((secret == null) ? 0 : Arrays.hashCode(secret.getEncoded()));
      return result;
    }
  
    @Override
    public boolean equals(Object obj) {
      if (obj == null || !(obj instanceof AuthenticationKey)) {
        return false;
      }
      AuthenticationKey other = (AuthenticationKey)obj;
      return id == other.getKeyId() &&
          expirationDate == other.getExpiration() &&
          (secret == null ? other.getKey() == null :
              other.getKey() != null &&
                  Bytes.equals(secret.getEncoded(), other.getKey().getEncoded()));       
    }
  
    @Override
    public String toString() {
      StringBuilder buf = new StringBuilder();
      buf.append("AuthenticationKey[ ")
         .append("id=").append(id)
         .append(", expiration=").append(expirationDate)
         .append(" ]");
      return buf.toString();
    }
  
   @Override
   public void write(DataOutput out) throws IOException {
     WritableUtils.writeVInt(out, id);
     WritableUtils.writeVLong(out, expirationDate);
     if (secret == null) {
       WritableUtils.writeVInt(out, -1);
     } else {
       byte[] keyBytes = secret.getEncoded();
       WritableUtils.writeVInt(out, keyBytes.length);
       out.write(keyBytes);
     }
   }
 
   @Override
   public void readFields(DataInput in) throws IOException {
     id = WritableUtils.readVInt(in);
     expirationDate = WritableUtils.readVLong(in);
     int keyLength = WritableUtils.readVInt(in);
     if (keyLength < 0) {
       secret = null;
     } else {
       byte[] keyBytes = new byte[keyLength];
       in.readFully(keyBytes);
       secret = AuthenticationTokenSecretManager.createSecretKey(keyBytes);
     }
   }
 }