/*
* 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.mina.proxy.utils;
import java.io.UnsupportedEncodingException;
/**
* ByteUtilities.java - Byte manipulation functions.
*
* @author <a href="http://mina.apache.org">Apache MINA Project</a>
* @since MINA 2.0.0-M3
*/
public class ByteUtilities {
/**
* Returns the integer represented by up to 4 bytes in network byte order.
*
* @param buf the buffer to read the bytes from
* @param start
* @param count
* @return the integer value
*/
public static int networkByteOrderToInt(byte[] buf, int start, int count) {
if (count > 4) {
throw new IllegalArgumentException("Cannot handle more than 4 bytes");
}
int result = 0;
for (int i = 0; i < count; i++) {
result <<= 8;
result |= (buf[start + i] & 0xff);
}
return result;
}
/**
* Encodes an integer into up to 4 bytes in network byte order.
*
* @param num the int to convert to a byte array
* @param count the number of reserved bytes for the write operation
* @return the resulting byte array
*/
public static byte[] intToNetworkByteOrder(int num, int count) {
byte[] buf = new byte[count];
intToNetworkByteOrder(num, buf, 0, count);
return buf;
}
/**
* Encodes an integer into up to 4 bytes in network byte order in the
* supplied buffer starting at <code>start</code> offset and writing
* <code>count</code> bytes.
*
* @param num the int to convert to a byte array
* @param buf the buffer to write the bytes to
* @param start the offset from beginning for the write operation
* @param count the number of reserved bytes for the write operation
*/
public static void intToNetworkByteOrder(int num, byte[] buf, int start, int count) {
if (count > 4) {
throw new IllegalArgumentException("Cannot handle more than 4 bytes");
}
for (int i = count - 1; i >= 0; i--) {
buf[start + i] = (byte) (num & 0xff);
num >>>= 8;
}
}
/**
* Write a 16 bit short as LITTLE_ENDIAN.
*
* @param v the short to write
*/
public final static byte[] writeShort(short v) {
return writeShort(v, new byte[2], 0);
}
/**
* Write a 16 bit short as LITTLE_ENDIAN to
* the given array <code>b</code> at offset <code>offset</code>.
*
* @param v the short to write
* @param b the byte array to write to
* @param offset the offset at which to start writing in the array
*/
public final static byte[] writeShort(short v, byte[] b, int offset) {
b[offset] = (byte) v;
b[offset + 1] = (byte) (v >> 8);
return b;
}
/**
* Write a 32 bit int as LITTLE_ENDIAN.
*
* @param v the int to write
*/
public final static byte[] writeInt(int v) {
return writeInt(v, new byte[4], 0);
}
/**
* Write a 32 bit int as LITTLE_ENDIAN to
* the given array <code>b</code> at offset <code>offset</code>.
*
* @param v the int to write
* @param b the byte array to write to
* @param offset the offset at which to start writing in the array
*/
public final static byte[] writeInt(int v, byte[] b, int offset) {
b[offset] = (byte) v;
b[offset + 1] = (byte) (v >> 8);
b[offset + 2] = (byte) (v >> 16);
b[offset + 3] = (byte) (v >> 24);
return b;
}
/**
* Invert the endianness of words (4 bytes) in the given byte array
* starting at the given offset and repeating length/4 times.
* eg: b0b1b2b3 -> b3b2b1b0
*
* @param b the byte array
* @param offset the offset at which to change word start
* @param length the number of bytes on which to operate
* (should be a multiple of 4)
*/
public final static void changeWordEndianess(byte[] b, int offset, int length) {
byte tmp;
for (int i = offset; i < offset + length; i += 4) {
tmp = b[i];
b[i] = b[i + 3];
b[i + 3] = tmp;
tmp = b[i + 1];
b[i + 1] = b[i + 2];
b[i + 2] = tmp;
}
}
/**
* Invert two bytes in the given byte array starting at the given
* offset and repeating the inversion length/2 times.
* eg: b0b1 -> b1b0
*
* @param b the byte array
* @param offset the offset at which to change word start
* @param length the number of bytes on which to operate
* (should be a multiple of 2)
*/
public final static void changeByteEndianess(byte[] b, int offset, int length) {
byte tmp;
for (int i = offset; i < offset + length; i += 2) {
tmp = b[i];
b[i] = b[i + 1];
b[i + 1] = tmp;
}
}
/**
* Converts an OEM string as defined in NTLM protocol (eg ASCII charset)
* to a byte array.
*
* @param s the string to convert
* @return the result byte array
* @throws UnsupportedEncodingException if the string is not an OEM string
*/
public final static byte[] getOEMStringAsByteArray(String s) throws UnsupportedEncodingException {
return s.getBytes("ASCII");
}
/**
* Converts an UTF-16LE string as defined in NTLM protocol to a byte array.
*
* @param s the string to convert
* @return the result byte array
* @throws UnsupportedEncodingException if the string is not an UTF-16LE string
*/
public final static byte[] getUTFStringAsByteArray(String s) throws UnsupportedEncodingException {
return s.getBytes("UTF-16LE");
}
/**
* Encodes the string to a byte array using UTF-16LE or the ASCII charset
* in function of the <code>useUnicode</code> argument.
*
* @param s the string to encode
* @param useUnicode if true then string is encoded to UTF-16LE
* otherwise to ASCII
* @return the encoded string as a byte array
* @throws UnsupportedEncodingException if encoding fails
*/
public final static byte[] encodeString(String s, boolean useUnicode) throws UnsupportedEncodingException {
if (useUnicode) {
return getUTFStringAsByteArray(s);
}
return getOEMStringAsByteArray(s);
}
/**
* Returns a hexadecimal representation of the given byte array.
*
* @param bytes the array to output to an hex string
* @return the hex representation as a string
*/
public static String asHex(byte[] bytes) {
return asHex(bytes, null);
}
/**
* Returns a hexadecimal representation of the given byte array.
*
* @param bytes the array to output to an hex string
* @param separator the separator to use between each byte in the output
* string. If null no char is inserted between each byte value.
* @return the hex representation as a string
*/
public static String asHex(byte[] bytes, String separator) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
String code = Integer.toHexString(bytes[i] & 0xFF);
if ((bytes[i] & 0xFF) < 16) {
sb.append('0');
}
sb.append(code);
if (separator != null && i < bytes.length - 1) {
sb.append(separator);
}
}
return sb.toString();
}
/**
* Converts a hex string representation to a byte array.
*
* @param hex the string holding the hex values
* @return the resulting byte array
*/
public static byte[] asByteArray(String hex) {
byte[] bts = new byte[hex.length() / 2];
for (int i = 0; i < bts.length; i++) {
bts[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
}
return bts;
}
/**
* Reads an int from 4 bytes of the given array at offset 0.
*
* @param b the byte array to read
* @return the integer value
*/
public static final int makeIntFromByte4(byte[] b) {
return makeIntFromByte4(b, 0);
}
/**
* Reads an int from 4 bytes of the given array at the given offset.
*
* @param b the byte array to read
* @param offset the offset at which to start
* @return the int value
*/
public static final int makeIntFromByte4(byte[] b, int offset) {
return b[offset] << 24 | (b[offset + 1] & 0xff) << 16 | (b[offset + 2] & 0xff) << 8 | (b[offset + 3] & 0xff);
}
/**
* Reads an int from 2 bytes of the given array at offset 0.
*
* @param b the byte array to read
* @return the int value
*/
public static final int makeIntFromByte2(byte[] b) {
return makeIntFromByte2(b, 0);
}
/**
* Reads an int from 2 bytes of the given array at the given offset.
*
* @param b the byte array to read
* @param offset the offset at which to start
* @return the int value
*/
public static final int makeIntFromByte2(byte[] b, int offset) {
return (b[offset] & 0xff) << 8 | (b[offset + 1] & 0xff);
}
/**
* Returns true if the flag <code>testFlag</code> is set in the
* <code>flags</code> flagset.
*
* @param flagSet the flagset to test
* @param testFlag the flag we search the presence of
* @return true if testFlag is present in the flagset, false otherwise.
*/
public final static boolean isFlagSet(int flagSet, int testFlag) {
return (flagSet & testFlag) > 0;
}
}