https://openjdk.java.net/ 
/*
 * Copyright (c) 2005, 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
 * questions.
 */

package sun.security.jgss;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.EOFException;
import sun.security.util.*;


Utilities for processing GSS Tokens.

/**
 * Utilities for processing GSS Tokens.
 *
 */

public abstract class GSSToken {

    
Copies an integer value to a byte array in little endian form.

Params:
  • value – the integer value to write
  • array – the byte array into which the integer must be copied. It
is assumed that the array will be large enough to hold the 4 bytes of
the integer.
/**
     * Copies an integer value to a byte array in little endian form.
     * @param value the integer value to write
     * @param array the byte array into which the integer must be copied. It
     * is assumed that the array will be large enough to hold the 4 bytes of
     * the integer.
     */
    public static final void writeLittleEndian(int value, byte[] array) {
        writeLittleEndian(value, array, 0);
    }

    
Copies an integer value to a byte array in little endian form.

Params:
  • value – the integer value to write
  • array – the byte array into which the integer must be copied. It
is assumed that the array will be large enough to hold the 4 bytes of
the integer.
  • pos – the position at which to start writing
/**
     * Copies an integer value to a byte array in little endian form.
     * @param value the integer value to write
     * @param array the byte array into which the integer must be copied. It
     * is assumed that the array will be large enough to hold the 4 bytes of
     * the integer.
     * @param pos the position at which to start writing
     */
    public static final void writeLittleEndian(int value, byte[] array,
                                               int pos) {
        array[pos++] = (byte)(value);
        array[pos++] = (byte)((value>>>8));
        array[pos++] = (byte)((value>>>16));
        array[pos++] = (byte)((value>>>24));
    }

    public static final void writeBigEndian(int value, byte[] array) {
        writeBigEndian(value, array, 0);
    }

    public static final void writeBigEndian(int value, byte[] array,
                                               int pos) {
        array[pos++] = (byte)((value>>>24));
        array[pos++] = (byte)((value>>>16));
        array[pos++] = (byte)((value>>>8));
        array[pos++] = (byte)(value);
    }

    
Reads an integer value from a byte array in little endian form. This
method allows the reading of two byte values as well as four bytes
values both of which are needed in the Kerberos v5 GSS-API mechanism.

Params:
  • data – the array containing the bytes of the integer value
  • pos – the offset in the array
@sizethe number of bytes to read from the array.
Returns:the integer value
/**
     * Reads an integer value from a byte array in little endian form. This
     * method allows the reading of two byte values as well as four bytes
     * values both of which are needed in the Kerberos v5 GSS-API mechanism.
     *
     * @param data the array containing the bytes of the integer value
     * @param pos the offset in the array
     * @size the number of bytes to read from the array.
     * @return the integer value
     */
    public static final int readLittleEndian(byte[] data, int pos, int size) {
        int retVal = 0;
        int shifter = 0;
        while (size > 0) {
            retVal += (data[pos] & 0xff) << shifter;
            shifter += 8;
            pos++;
            size--;
        }
        return retVal;
    }

    public static final int readBigEndian(byte[] data, int pos, int size) {
        int retVal = 0;
        int shifter = (size-1)*8;
        while (size > 0) {
            retVal += (data[pos] & 0xff) << shifter;
            shifter -= 8;
            pos++;
            size--;
        }
        return retVal;
    }

    
Writes a two byte integer value to a OutputStream.

Params:
  • val – the integer value. It will lose the high-order two bytes.
  • os – the OutputStream to write to
Throws:
  • IOException – if an error occurs while writing to the OutputStream
/**
     * Writes a two byte integer value to a OutputStream.
     *
     * @param val the integer value. It will lose the high-order two bytes.
     * @param os the OutputStream to write to
     * @throws IOException if an error occurs while writing to the OutputStream
     */
    public static final void writeInt(int val, OutputStream os)
        throws IOException {
        os.write(val>>>8);
        os.write(val);
    }

    
Writes a two byte integer value to a byte array.

Params:
  • val – the integer value. It will lose the high-order two bytes.
  • dest – the byte array to write to
  • pos – the offset to start writing to
/**
     * Writes a two byte integer value to a byte array.
     *
     * @param val the integer value. It will lose the high-order two bytes.
     * @param dest the byte array to write to
     * @param pos the offset to start writing to
     */
    public static final int writeInt(int val, byte[] dest, int pos) {
        dest[pos++] = (byte)(val>>>8);
        dest[pos++] = (byte)val;
        return pos;
    }

    
Reads a two byte integer value from an InputStream.

Params:
  • is – the InputStream to read from
Throws:
  • IOException – if some errors occurs while reading the integer
bytes.
@returnsthe integer value
/**
     * Reads a two byte integer value from an InputStream.
     *
     * @param is the InputStream to read from
     * @returns the integer value
     * @throws IOException if some errors occurs while reading the integer
     * bytes.
     */
    public static final int readInt(InputStream is) throws IOException {
        return (((0xFF & is.read()) << 8)
                 | (0xFF & is.read()));
    }

    
Reads a two byte integer value from a byte array.

Params:
  • src – the byte arra to read from
  • pos – the offset to start reading from
@returnsthe integer value
/**
     * Reads a two byte integer value from a byte array.
     *
     * @param src the byte arra to read from
     * @param pos the offset to start reading from
     * @returns the integer value
     */
    public static final int readInt(byte[] src, int pos) {
        return ((0xFF & src[pos])<<8 | (0xFF & src[pos+1]));
    }

    
Blocks till the required number of bytes have been read from the
input stream.

Params:
  • is – the InputStream to read from
  • buffer – the buffer to store the bytes into
Throws:
@paramthrows EOFException if EOF is reached before all bytes are
read.
/**
     * Blocks till the required number of bytes have been read from the
     * input stream.
     *
     * @param is the InputStream to read from
     * @param buffer the buffer to store the bytes into
     * @param throws EOFException if EOF is reached before all bytes are
     * read.
     * @throws IOException is an error occurs while reading
     */
    public static final void readFully(InputStream is, byte[] buffer)
        throws IOException {
        readFully(is, buffer, 0, buffer.length);
    }

    
Blocks till the required number of bytes have been read from the
input stream.

Params:
  • is – the InputStream to read from
  • buffer – the buffer to store the bytes into
  • offset – the offset to start storing at
  • len – the number of bytes to read
Throws:
@paramthrows EOFException if EOF is reached before all bytes are
read.
/**
     * Blocks till the required number of bytes have been read from the
     * input stream.
     *
     * @param is the InputStream to read from
     * @param buffer the buffer to store the bytes into
     * @param offset the offset to start storing at
     * @param len the number of bytes to read
     * @param throws EOFException if EOF is reached before all bytes are
     * read.
     * @throws IOException is an error occurs while reading
     */
    public static final void readFully(InputStream is,
                                       byte[] buffer, int offset, int len)
        throws IOException {
        int temp;
        while (len > 0) {
            temp = is.read(buffer, offset, len);
            if (temp == -1)
                throw new EOFException("Cannot read all "
                                       + len
                                       + " bytes needed to form this token!");
            offset += temp;
            len -= temp;
        }
    }

    public static final void debug(String str) {
        System.err.print(str);
    }

    public static final  String getHexBytes(byte[] bytes) {
        return getHexBytes(bytes, 0, bytes.length);
    }

    public static final  String getHexBytes(byte[] bytes, int len) {
        return getHexBytes(bytes, 0, len);
    }

    public static final String getHexBytes(byte[] bytes, int pos, int len) {
        StringBuffer sb = new StringBuffer();
        for (int i = pos; i < (pos+len); i++) {
            int b1 = (bytes[i]>>4) & 0x0f;
            int b2 = bytes[i] & 0x0f;

            sb.append(Integer.toHexString(b1));
            sb.append(Integer.toHexString(b2));
            sb.append(' ');
        }
        return sb.toString();
    }

}