gt:         byte[] challengeBytes = getChallenge();
context: /* jcifs smb client library in Java
   * Copyright (C) 2002  "Michael B. Allen" <jcifs at samba dot org>
   *                 "Eric Glass" <jcifs at samba dot org>
   *
   * This library 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 2.1 of the License, or (at your option) any later version.
   *
   * This library 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package jcifs.ntlmssp;
  
  
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import jcifs.CIFSContext;
  
  
  /**
   * Represents an NTLMSSP Type-2 message.
   */
  public class Type2Message extends NtlmMessage {
  
      private static final Logger log = LoggerFactory.getLogger(Type2Message.class);
  
      private byte[] challenge;
      private String target;
      private byte[] context;
      private byte[] targetInformation;
  
      private static final Map<String, byte[]> TARGET_INFO_CACHE = new HashMap<>();
  
  
      private static byte[] getDefaultTargetInfo ( CIFSContext tc ) {
          String domain = tc.getConfig().getDefaultDomain();
          byte[] ti = TARGET_INFO_CACHE.get(domain);
          if ( ti != null ) {
              return ti;
          }
  
          ti = makeTargetInfo(tc, domain);
          TARGET_INFO_CACHE.put(domain, ti);
          return ti;
      }
  
  
      /**
       * @param domain
       * @param domainLength
       * @param server
       * @return
       */
      private static byte[] makeTargetInfo ( CIFSContext tc, String domainStr ) {
          byte[] domain = new byte[0];
          if ( domainStr != null ) {
              try {
                  domain = domainStr.getBytes(UNI_ENCODING);
              }
              catch ( IOException ex ) {
                  log.debug("Failed to get domain bytes", ex);
              }
          }
          int domainLength = domain.length;
          byte[] server = new byte[0];
          String host = tc.getNameServiceClient().getLocalHost().getHostName();
          if ( host != null ) {
              try {
                  server = host.getBytes(UNI_ENCODING);
              }
              catch ( IOException ex ) {
                  log.debug("Failed to get host bytes", ex);
              }
          }
          int serverLength = server.length;
          byte[] targetInfo = new byte[ ( domainLength > 0 ? domainLength + 4 : 0 ) + ( serverLength > 0 ? serverLength + 4 : 0 ) + 4];
          int offset = 0;
          if ( domainLength > 0 ) {
              writeUShort(targetInfo, offset, 2);
              offset += 2;
              writeUShort(targetInfo, offset, domainLength);
              offset += 2;
              System.arraycopy(domain, 0, targetInfo, offset, domainLength);
              offset += domainLength;
          }
          if ( serverLength > 0 ) {
              writeUShort(targetInfo, offset, 1);
              offset += 2;
              writeUShort(targetInfo, offset, serverLength);
              offset += 2;
              System.arraycopy(server, 0, targetInfo, offset, serverLength);
          }
          return targetInfo;
      }
  
  
      /**
       * Creates a Type-2 message using default values from the current
       * environment.
       * 
       * @param tc
       *            context to use
       */
      public Type2Message ( CIFSContext tc ) {
          this(tc, getDefaultFlags(tc), null, null);
      }
  
  
      /**
       * Creates a Type-2 message in response to the given Type-1 message
       * using default values from the current environment.
       * 
       * @param tc
       *            context to use
       * @param type1
       *            The Type-1 message which this represents a response to.
       */
      public Type2Message ( CIFSContext tc, Type1Message type1 ) {
          this(tc, type1, null, null);
      }
  
  
      /**
       * Creates a Type-2 message in response to the given Type-1 message.
       * 
       * @param tc
       *            context to use
       * @param type1
       *            The Type-1 message which this represents a response to.
       * @param challenge
       *            The challenge from the domain controller/server.
       * @param target
       *            The authentication target.
       */
      public Type2Message ( CIFSContext tc, Type1Message type1, byte[] challenge, String target ) {
          this(
              tc,
              getDefaultFlags(tc, type1),
              challenge,
              ( type1 != null && target == null && type1.getFlag(NTLMSSP_REQUEST_TARGET) ) ? tc.getConfig().getDefaultDomain() : target);
      }
  
  
      /**
       * Creates a Type-2 message with the specified parameters.
       * 
       * @param tc
       *            context to use
       * @param flags
       *            The flags to apply to this message.
       * @param challenge
       *            The challenge from the domain controller/server.
       * @param target
       *            The authentication target.
       */
      public Type2Message ( CIFSContext tc, int flags, byte[] challenge, String target ) {
          setFlags(flags);
          setChallenge(challenge);
          setTarget(target);
          if ( target != null ) {
              setTargetInformation(getDefaultTargetInfo(tc));
          }
      }
  
  
      /**
       * Creates a Type-2 message using the given raw Type-2 material.
       *
       * @param material
       *            The raw Type-2 material used to construct this message.
       * @throws IOException
       *             If an error occurs while parsing the material.
       */
      public Type2Message ( byte[] material ) throws IOException {
          parse(material);
      }
  
  
      /**
       * Returns the default flags for a generic Type-2 message in the
       * current environment.
       * 
       * @param tc
       *            context to use
       * @return An <code>int</code> containing the default flags.
       */
      public static int getDefaultFlags ( CIFSContext tc ) {
          return NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_VERSION
                  | ( tc.getConfig().isUseUnicode() ? NTLMSSP_NEGOTIATE_UNICODE : NTLMSSP_NEGOTIATE_OEM );
      }
  
  
      /**
       * Returns the default flags for a Type-2 message created in response
       * to the given Type-1 message in the current environment.
       * 
       * @param tc
       *            context to use
       * @param type1
       *            request message
       *
       * @return An <code>int</code> containing the default flags.
       */
      public static int getDefaultFlags ( CIFSContext tc, Type1Message type1 ) {
          if ( type1 == null )
              return getDefaultFlags(tc);
          int flags = NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_VERSION;
          int type1Flags = type1.getFlags();
          flags |= ( ( type1Flags & NTLMSSP_NEGOTIATE_UNICODE ) != 0 ) ? NTLMSSP_NEGOTIATE_UNICODE : NTLMSSP_NEGOTIATE_OEM;
          if ( ( type1Flags & NTLMSSP_REQUEST_TARGET ) != 0 ) {
              String domain = tc.getConfig().getDefaultDomain();
              if ( domain != null ) {
                  flags |= NTLMSSP_REQUEST_TARGET | NTLMSSP_TARGET_TYPE_DOMAIN;
              }
          }
          return flags;
      }
  
  
      /**
       * Returns the challenge for this message.
       *
       * @return A <code>byte[]</code> containing the challenge.
       */
      public byte[] getChallenge () {
          return this.challenge;
      }
  
  
      /**
       * Sets the challenge for this message.
       *
       * @param challenge
       *            The challenge from the domain controller/server.
       */
      public void setChallenge ( byte[] challenge ) {
          this.challenge = challenge;
      }
  
  
      /**
       * Returns the authentication target.
       *
       * @return A <code>String</code> containing the authentication target.
       */
      public String getTarget () {
          return this.target;
      }
  
  
      /**
       * Sets the authentication target.
       *
       * @param target
       *            The authentication target.
       */
      public void setTarget ( String target ) {
          this.target = target;
      }
  
  
      /**
       * Returns the target information block.
       *
       * @return A <code>byte[]</code> containing the target information block.
       *         The target information block is used by the client to create an
       *         NTLMv2 response.
       */
      public byte[] getTargetInformation () {
          return this.targetInformation;
      }
  
  
      /**
       * Sets the target information block.
       * The target information block is used by the client to create
       * an NTLMv2 response.
       * 
       * @param targetInformation
       *            The target information block.
       */
      public void setTargetInformation ( byte[] targetInformation ) {
          this.targetInformation = targetInformation;
      }
  
  
      /**
       * Returns the local security context.
       *
       * @return A <code>byte[]</code> containing the local security
       *         context. This is used by the client to negotiate local
       *         authentication.
       */
      public byte[] getContext () {
          return this.context;
      }
  
  
      /**
       * Sets the local security context. This is used by the client
       * to negotiate local authentication.
       *
       * @param context
       *            The local security context.
       */
      public void setContext ( byte[] context ) {
          this.context = context;
      }
  
  
      @Override
      public byte[] toByteArray () throws IOException {
          int size = 48;
          int flags = getFlags();
          String targetName = getTarget();
          byte[] targetInformationBytes = getTargetInformation();
          byte[] targetBytes = new byte[0];
  
          if ( getFlag(NTLMSSP_REQUEST_TARGET) ) {
              if ( targetName != null && targetName.length() != 0 ) {
                  targetBytes = ( flags & NTLMSSP_NEGOTIATE_UNICODE ) != 0 ? targetName.getBytes(UNI_ENCODING)
                          : targetName.toUpperCase().getBytes(getOEMEncoding());
                  size += targetBytes.length;
              }
              else {
                  flags &= ( 0xffffffff ^ NTLMSSP_REQUEST_TARGET );
              }
          }
  
          if ( targetInformationBytes != null ) {
              size += targetInformationBytes.length;
              flags |= NTLMSSP_NEGOTIATE_TARGET_INFO;
          }
  
          if ( getFlag(NTLMSSP_NEGOTIATE_VERSION) ) {
              size += 8;
          }
  
          byte[] type2 = new byte[size];
          int pos = 0;
  
          System.arraycopy(NTLMSSP_SIGNATURE, 0, type2, pos, NTLMSSP_SIGNATURE.length);
          pos += NTLMSSP_SIGNATURE.length;
  
          writeULong(type2, pos, NTLMSSP_TYPE2);
          pos += 4;
  
          // TargetNameFields
          int targetNameOff = writeSecurityBuffer(type2, pos, targetBytes);
          pos += 8;
  
          writeULong(type2, pos, flags);
          pos += 4;
  
          // ServerChallenge
          byte[] challengeBytes = getChallenge();
          System.arraycopy(challengeBytes != null ? challengeBytes : new byte[8], 0, type2, pos, 8);
          pos += 8;
  
          // Reserved
          byte[] contextBytes = getContext();
          System.arraycopy(contextBytes != null ? contextBytes : new byte[8], 0, type2, pos, 8);
          pos += 8;
  
          // TargetInfoFields
          int targetInfoOff = writeSecurityBuffer(type2, pos, targetInformationBytes);
          pos += 8;
  
          if ( getFlag(NTLMSSP_NEGOTIATE_VERSION) ) {
              System.arraycopy(NTLMSSP_VERSION, 0, type2, pos, NTLMSSP_VERSION.length);
              pos += NTLMSSP_VERSION.length;
          }
  
          pos += writeSecurityBufferContent(type2, pos, targetNameOff, targetBytes);
          pos += writeSecurityBufferContent(type2, pos, targetInfoOff, targetInformationBytes);
  
          return type2;
      }
  
  
      @Override
      public String toString () {
          String targetString = getTarget();
  