text: /*
   * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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 Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
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   */
  
  package sun.security.jgss.krb5;
  
  import org.ietf.jgss.*;
  import sun.security.jgss.*;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.IOException;
  import java.io.ByteArrayOutputStream;
  import java.util.Arrays;
  import sun.security.krb5.Confounder;
  
  /**
   * This class represents the new format of GSS tokens, as specified in RFC
   * 4121, emitted by the GSSContext.wrap() call. It is a MessageToken except
   * that it also contains plaintext or encrypted data at the end. A WrapToken
   * has certain other rules that are peculiar to it and different from a
   * MICToken, which is another type of MessageToken. All data in a WrapToken is
   * prepended by a random confounder of 16 bytes. Thus, all application data
   * is replaced by (confounder || data || tokenHeader || checksum).
   *
   * @author Seema Malkani
   */
  class WrapToken_v2 extends MessageToken_v2 {
  
      // Accessed by CipherHelper
      byte[] confounder = null;
  
      private final boolean privacy;
  
      /**
       * Constructs a WrapToken from token bytes obtained from the
       * peer.
       * @param context the mechanism context associated with this
       * token
       * @param tokenBytes the bytes of the token
       * @param tokenOffset the offset of the token
       * @param tokenLen the length of the token
       * @param prop the MessageProp into which characteristics of the
       * parsed token will be stored.
       * @throws GSSException if the token is defective
       */
      public WrapToken_v2(Krb5Context context,
                       byte[] tokenBytes, int tokenOffset, int tokenLen,
                       MessageProp prop)  throws GSSException {
  
          super(Krb5Token.WRAP_ID_v2, context,
                tokenBytes, tokenOffset, tokenLen, prop);
          this.privacy = prop.getPrivacy();
      }
  
      /**
       * Constructs a WrapToken from token bytes read on the fly from
       * an InputStream.
       * @param context the mechanism context associated with this
       * token
       * @param is the InputStream containing the token bytes
       * @param prop the MessageProp into which characteristics of the
       * parsed token will be stored.
       * @throws GSSException if the token is defective or if there is
       * a problem reading from the InputStream
       */
      public WrapToken_v2(Krb5Context context,
                       InputStream is, MessageProp prop)
          throws GSSException {
  
          super(Krb5Token.WRAP_ID_v2, context, is, prop);
          this.privacy = prop.getPrivacy();
      }
  
      /**
       * Obtains the application data that was transmitted in this
       * WrapToken.
       * @return a byte array containing the application data
       * @throws GSSException if an error occurs while decrypting any
       * cipher text and checking for validity
       */
      public byte[] getData() throws GSSException {
  
          byte[] temp = new byte[tokenDataLen];
          int len = getData(temp, 0);
          return Arrays.copyOf(temp, len);
      }
  
      /**
       * Obtains the application data that was transmitted in this
       * WrapToken, writing it into an application provided output
       * array.
       * @param dataBuf the output buffer into which the data must be
       * written
       * @param dataBufOffset the offset at which to write the data
       * @return the size of the data written
       * @throws GSSException if an error occurs while decrypting any
       * cipher text and checking for validity
       */
      public int getData(byte[] dataBuf, int dataBufOffset)
          throws GSSException {
  
          // debug("WrapToken cons: data is token is [" +
          //      getHexBytes(tokenBytes, tokenOffset, tokenLen) + "]\n");
  
          // Do decryption if this token was privacy protected.
          if (privacy) {
  
              // decrypt data
              cipherHelper.decryptData(this, tokenData, 0, tokenDataLen,
                                  dataBuf, dataBufOffset, getKeyUsage());
  
              return tokenDataLen - CONFOUNDER_SIZE -
                  TOKEN_HEADER_SIZE - cipherHelper.getChecksumLength();
          } else {
  
              // Token data is in cleartext
              // debug("\t\tNo encryption was performed by peer.\n");
  
              // data
              int data_length = tokenDataLen - cipherHelper.getChecksumLength();
              System.arraycopy(tokenData, 0,
                               dataBuf, dataBufOffset,
                               data_length);
              // debug("\t\tData is: " + getHexBytes(dataBuf, data_length));
  
              /*
               * Make sure checksum is not corrupt
               */
              if (!verifySign(dataBuf, dataBufOffset, data_length)) {
                  throw new GSSException(GSSException.BAD_MIC, -1,
                           "Corrupt checksum in Wrap token");
              }
              return data_length;
          }
      }
  
      /**
       * Writes a WrapToken_v2 object
       */
      public WrapToken_v2(Krb5Context context, MessageProp prop,
                       byte[] dataBytes, int dataOffset, int dataLen)
              throws GSSException {
  
          super(Krb5Token.WRAP_ID_v2, context);
  
          confounder = Confounder.bytes(CONFOUNDER_SIZE);
  
          // debug("\nWrapToken cons: data to wrap is [" +
          // getHexBytes(confounder) + " " +
          // getHexBytes(dataBytes, dataOffset, dataLen) + "]\n");
  
          genSignAndSeqNumber(prop, dataBytes, dataOffset, dataLen);
  
          /*
           * If the application decides to ask for privacy when the context
           * did not negotiate for it, do not provide it. The peer might not
           * have support for it. The app will realize this with a call to
           * pop.getPrivacy() after wrap().
           */
          if (!context.getConfState())
              prop.setPrivacy(false);
  
          privacy = prop.getPrivacy();
  
          if (!privacy) {
              // Wrap Tokens (without confidentiality) =
              // { 16 byte token_header | plaintext | 12-byte HMAC }
              // where HMAC is on { plaintext | token_header }
  
              tokenData = new byte[dataLen + checksum.length];
              System.arraycopy(dataBytes, dataOffset, tokenData, 0, dataLen);
              System.arraycopy(checksum, 0, tokenData, dataLen, checksum.length);
          } else {
              // Wrap Tokens (with confidentiality) =
              // { 16 byte token_header |
              // Encrypt(16-byte confounder | plaintext | token_header) |
              // 12-byte HMAC }
  
              tokenData = cipherHelper.encryptData(this, confounder, getTokenHeader(),
                  dataBytes, dataOffset, dataLen, getKeyUsage());
          }
      }
  
      public void encode(OutputStream os) throws IOException {
          encodeHeader(os);
          os.write(tokenData);
      }
  
      public byte[] encode() throws IOException {
          ByteArrayOutputStream bos = new ByteArrayOutputStream(
                  MessageToken_v2.TOKEN_HEADER_SIZE + tokenData.length);
          encode(bos);
          return bos.toByteArray();
      }
  
      public int encode(byte[] outToken, int offset) throws IOException {
          byte[] token = encode();
          System.arraycopy(token, 0, outToken, offset, token.length);
          return token.length;
      }
  
      // This implementation is way to conservative. And it certainly
      // doesn't return the maximum limit.
      static int getSizeLimit(int qop, boolean confReq, int maxTokenSize,
          CipherHelper ch) throws GSSException {
          return (GSSHeader.getMaxMechTokenSize(OID, maxTokenSize) -
                  (TOKEN_HEADER_SIZE + ch.getChecksumLength() + CONFOUNDER_SIZE)
                  - 8 /* safety */);
      }
  }
  