package org.metricshub.ipmi.core.coding.commands.session;
   
   /*-
    * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
    * IPMI Java Client
    * ჻჻჻჻჻჻
    * Copyright 2023 Verax Systems, MetricsHub
    * ჻჻჻჻჻჻
    * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Lesser General Public License as
   * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Lesser Public License for more details.
   *
   * You should have received a copy of the GNU General Lesser Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-3.0.html>.
   * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
   */
  
  import org.metricshub.ipmi.core.coding.commands.IpmiCommandCoder;
  import org.metricshub.ipmi.core.coding.commands.IpmiVersion;
  import org.metricshub.ipmi.core.coding.commands.ResponseData;
  import org.metricshub.ipmi.core.coding.payload.CompletionCode;
  import org.metricshub.ipmi.core.coding.payload.IpmiPayload;
  import org.metricshub.ipmi.core.coding.payload.PlainMessage;
  import org.metricshub.ipmi.core.coding.payload.lan.IPMIException;
  import org.metricshub.ipmi.core.coding.payload.lan.NetworkFunction;
  import org.metricshub.ipmi.core.coding.protocol.AuthenticationType;
  import org.metricshub.ipmi.core.coding.protocol.IpmiMessage;
  import org.metricshub.ipmi.core.coding.protocol.Ipmiv20Message;
  import org.metricshub.ipmi.core.coding.protocol.PayloadType;
  import org.metricshub.ipmi.core.coding.protocol.encoder.Protocolv20Encoder;
  import org.metricshub.ipmi.core.coding.security.CipherSuite;
  import org.metricshub.ipmi.core.coding.security.ConfidentialityNone;
  import org.metricshub.ipmi.core.coding.security.SecurityConstants;
  import org.metricshub.ipmi.core.common.TypeConverter;
  
  import java.security.InvalidKeyException;
  import java.security.NoSuchAlgorithmException;
  
  /**
   * A wrapper for RMCP+ RAKP3 message and it's response - RAKP4 message.
   */
  public class Rakp3 extends IpmiCommandCoder {
  
      /**
       * Status of the previous message.
       */
      private byte statusCode;
  
      /**
       * The Managed System's Session ID for this session. Must be as returned by
       * the Managed System in the Open Session Response message.
       */
      private int managedSystemSessionId;
  
      private Rakp1 rakp1;
  
      private Rakp1ResponseData rakp1ResponseData;
  
      public void setStatusCode(byte statusCode) {
          this.statusCode = statusCode;
      }
  
      public byte getStatusCode() {
          return statusCode;
      }
  
      public void setManagedSystemSessionId(int managedSystemSessionId) {
          this.managedSystemSessionId = managedSystemSessionId;
      }
  
      public int getManagedSystemSessionId() {
          return managedSystemSessionId;
      }
  
      /**
       * Initiates class for decoding. Sets IPMI version to
       * {@link IpmiVersion#V20} since RAKP1 is a RMCP+ command. Sets
       * Authentication Type to RMCP+.
       *
       * @param cipherSuite
       *            - {@link CipherSuite} containing authentication,
       *            confidentiality and integrity algorithms for this session.
       *            Only authentication algorithm is used at this point of
       *            creating a session.
       * @param rakp1
       *            - RAKP Message 1 sent earlier in the authentification process
       * @param rakp1ResponseData
       *            - RAKP Message 2 received earlier in the authentification
       *            process
       *
       */
      public Rakp3(CipherSuite cipherSuite, Rakp1 rakp1,
             Rakp1ResponseData rakp1ResponseData) {
         super(IpmiVersion.V20, cipherSuite, AuthenticationType.RMCPPlus);
         this.rakp1 = rakp1;
         this.rakp1ResponseData = rakp1ResponseData;
         setCipherSuite(new CipherSuite((byte) 0, cipherSuite
                 .getAuthenticationAlgorithm().getCode(), (byte) 0, (byte) 0));
     }
 
     /**
      * Initiates class for encoding and decoding. Sets IPMI version to
      * {@link IpmiVersion#V20} since RAKP1 is a RMCP+ command. Sets
      * Authentication Type to RMCP+.
      *
      * @param statusCode
      *            - Status of the previous message.
      * @param managedSystemSessionId
      *            - The Managed System�s Session ID for this session. Must be as
      *            returned by the Managed System in the Open Session Response
      *            message.
      * @param cipherSuite
      *            - {@link CipherSuite} containing authentication,
      *            confidentiality and integrity algorithms for this session.
      *            Only authentication algorithm is used at this point of
      *            creating a session.
      * @param rakp1
      *            - RAKP Message 1 sent earlier in the authentification process
      * @param rakp1ResponseData
      *            - RAKP Message 2 received earlier in the authentification
      *            process
      */
     public Rakp3(byte statusCode, int managedSystemSessionId,
             CipherSuite cipherSuite, Rakp1 rakp1,
             Rakp1ResponseData rakp1ResponseData) {
         super(IpmiVersion.V20, cipherSuite, AuthenticationType.RMCPPlus);
         setStatusCode(statusCode);
         setManagedSystemSessionId(managedSystemSessionId);
         this.rakp1 = rakp1;
         this.rakp1ResponseData = rakp1ResponseData;
         setCipherSuite(new CipherSuite((byte) 0, cipherSuite
                 .getAuthenticationAlgorithm().getCode(), (byte) 0, (byte) 0));
     }
 
     @Override
     public IpmiMessage encodePayload(int messageSequenceNumber, int sessionSequenceNumber, int sessionId)
             throws NoSuchAlgorithmException, InvalidKeyException {
 
         if (sessionId != 0) {
             throw new IllegalArgumentException("Session ID must be 0");
         }
 
         Ipmiv20Message message = new Ipmiv20Message(new ConfidentialityNone());
 
         message.setPayloadType(PayloadType.Rakp3);
         message.setSessionID(0);
         message.setSessionSequenceNumber(0);
         message.setAuthenticationType(getAuthenticationType());
         message.setPayloadAuthenticated(getCipherSuite()
                 .getIntegrityAlgorithm().getCode() != SecurityConstants.IA_NONE);
         message.setPayloadEncrypted(false);
 
         message.setPayload(preparePayload(messageSequenceNumber));
 
         message.setAuthCode(getCipherSuite()
                 .getIntegrityAlgorithm()
                 .generateAuthCode(
                         message.getIntegrityAlgorithmBase(new Protocolv20Encoder())));
 
         return message;
     }
 
     @Override
     protected IpmiPayload preparePayload(int sequenceNumber)
             throws NoSuchAlgorithmException, InvalidKeyException {
         byte[] payload = new byte[8];
 
         payload[0] = TypeConverter.intToByte(sequenceNumber); // message
                                                                     // tag
 
         payload[1] = getStatusCode(); // last message status code
 
         payload[2] = 0; // reserved
         payload[3] = 0; // reserved
 
         byte[] manSesId = TypeConverter
                 .intToLittleEndianByteArray(getManagedSystemSessionId());
 
         System.arraycopy(manSesId, 0, payload, 4, 4); // managed system session
                                                         // id
 
         byte[] exchangeAuthCode = getCipherSuite().getAuthenticationAlgorithm()
                 .getKeyExchangeAuthenticationCode(
                         prepareKeyExchangeAuthenticationCodeBase(rakp1,
                                 rakp1ResponseData), rakp1.getPassword());
 
         byte[] result = null;
 
         if (exchangeAuthCode != null) {
             result = new byte[8 + exchangeAuthCode.length];
             System.arraycopy(exchangeAuthCode, 0, result, 8,
                     exchangeAuthCode.length);
         } else {
             result = new byte[8];
         }
 
         System.arraycopy(payload, 0, result, 0, 8);
 
         return new PlainMessage(result);
     }
 
     /**
      * @return byte array holding prepared base for calculating
      *         KeyExchangeAuthenticationCode for RAKP Message 3
      */
     private byte[] prepareKeyExchangeAuthenticationCodeBase(Rakp1 rakp1,
             Rakp1ResponseData responseData) {
         int length = 22;
         if (rakp1.getUsername() != null) {
             length += rakp1.getUsername().length();
         }
         byte[] keac = new byte[length];
 
         System.arraycopy(responseData.getManagedSystemRandomNumber(), 0, keac,
                 0, 16);
 
         System.arraycopy(TypeConverter.intToLittleEndianByteArray(responseData
                 .getRemoteConsoleSessionId()), 0, keac, 16, 4);
 
         keac[20] = TypeConverter.intToByte(encodePrivilegeLevel(rakp1
                 .getRequestedMaximumPrivilegeLevel()) | 0x10);
 
         if (rakp1.getUsername() != null) {
             keac[21] = TypeConverter.intToByte(rakp1.getUsername().length());
             if (rakp1.getUsername().length() > 0) {
                 System.arraycopy(rakp1.getUsername().getBytes(), 0, keac, 22,
                         rakp1.getUsername().length());
             }
         } else {
             keac[21] = 0;
         }
 
         return keac;
     }
 
     @Override
     public byte getCommandCode() {
         return 0;
     }
 
     @Override
     public NetworkFunction getNetworkFunction() {
         return null;
     }
 
     @Override
     public ResponseData getResponseData(IpmiMessage message) throws IPMIException, InvalidKeyException, NoSuchAlgorithmException {
 
         if (!isCommandResponse(message)) {
             throw new IllegalArgumentException("This is not RAKP 4 message!");
         }
 
         byte[] payload = message.getPayload().getPayloadData();
 
         Rakp3ResponseData data = new Rakp3ResponseData();
 
         data.setMessageTag(payload[0]);
 
         data.setStatusCode(payload[1]);
 
         if (payload[1] != 0) {
             throw new IPMIException(CompletionCode.parseInt(TypeConverter
                     .byteToInt(payload[1])));
         }
 
         if (payload.length < 8) {
             throw new IllegalArgumentException("Invalid payload length");
         }
 
         byte[] buffer = new byte[4];
 
         System.arraycopy(payload, 4, buffer, 0, 4);
 
         data.setConsoleSessionId(TypeConverter
                 .littleEndianByteArrayToInt(buffer));
 
         byte[] integrityCheck = null;
 
         if (payload.length > 8) {
             integrityCheck = new byte[getCipherSuite()
                     .getAuthenticationAlgorithm().getIntegrityCheckBaseLength()];
             System.arraycopy(payload, 8, integrityCheck, 0, getCipherSuite()
                     .getAuthenticationAlgorithm().getIntegrityCheckBaseLength());
         }
 
         if (!getCipherSuite().getAuthenticationAlgorithm().doIntegrityCheck(
                 prepareIntegrityCheckBase(rakp1, rakp1ResponseData),
                 integrityCheck, rakp1.calculateSik(rakp1ResponseData))) {
             throw new IllegalArgumentException("Integrity check failed");
         }
 
         return data;
     }
 
     /**
      * @return byte array holding prepared base for calculating Integrity Check
      */
     private byte[] prepareIntegrityCheckBase(Rakp1 rakp1,
             Rakp1ResponseData responseData) {
         byte[] icb = new byte[36];
 
         System.arraycopy(rakp1.getConsoleRandomNumber(), 0, icb, 0, 16);
 
         System.arraycopy(TypeConverter.intToLittleEndianByteArray(rakp1
                 .getManagedSystemSessionId()), 0, icb, 16, 4);
 
         System.arraycopy(responseData.getManagedSystemGuid(), 0, icb, 20, 16);
 
         return icb;
     }
 
     @Override
     public boolean isCommandResponse(IpmiMessage message) {
         return message instanceof Ipmiv20Message && ((Ipmiv20Message) message).getPayloadType() == PayloadType.Rakp4;
     }
 
 }