| /* |
| * Copyright 2005-2008 Les Hazlewood and original authors |
| * |
| * Licensed 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.jsecurity.codec; |
| |
| /** |
| * Hex encoder and decoder. |
| * |
| * <p>This class was borrowed from Apache Commons Codec SVN repository (rev. 560660 ) with modifications |
| * to enable Hex conversion without a full dependency on Commons Codec. We didn't want to reinvent the wheel of |
| * great work they've done, but also didn't want to force every JSecurity user to depend on the commons-codec.jar</p> |
| * |
| * <p>As per the Apache 2.0 license, the original copyright notice and all author and copyright information have |
| * remained in tact.</p> |
| * |
| * @since 1.1 |
| * @author Apache Software Foundation |
| * @author Les Hazlewood |
| */ |
| public class Hex { |
| |
| /** |
| * Used to build output as Hex |
| */ |
| private static final char[] DIGITS = { |
| '0', '1', '2', '3', '4', '5', '6', '7', |
| '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' |
| }; |
| |
| public static String encodeToString( byte[] bytes ) { |
| char[] encodedChars = encode( bytes ); |
| return new String( encodedChars ); |
| } |
| |
| /** |
| * Converts an array of bytes into an array of characters representing the hexidecimal values of each byte in order. |
| * The returned array will be double the length of the passed array, as it takes two characters to represent any |
| * given byte. |
| * |
| * @param data byte[] to convert to Hex characters |
| * @return A char[] containing hexidecimal characters |
| */ |
| public static char[] encode(byte[] data) { |
| |
| int l = data.length; |
| |
| char[] out = new char[l << 1]; |
| |
| // two characters form the hex value. |
| for (int i = 0, j = 0; i < l; i++) { |
| out[j++] = DIGITS[(0xF0 & data[i]) >>> 4 ]; |
| out[j++] = DIGITS[ 0x0F & data[i] ]; |
| } |
| |
| return out; |
| } |
| |
| /** |
| * Converts an array of character bytes representing hexidecimal values into an |
| * array of bytes of those same values. The returned array will be half the |
| * length of the passed array, as it takes two characters to represent any |
| * given byte. An exception is thrown if the passed char array has an odd |
| * number of elements. |
| * |
| * @param array An array of character bytes containing hexidecimal digits |
| * @return A byte array containing binary data decoded from |
| * the supplied byte array (representing characters). |
| * @throws IllegalArgumentException Thrown if an odd number of characters is supplied |
| * to this function |
| * @see #decode(char[]) |
| */ |
| public static byte[] decode(byte[] array) throws IllegalArgumentException { |
| String s = CodecSupport.toString(array); |
| return decode(s); |
| } |
| |
| public static byte[] decode( String hex ) { |
| return decode( hex.toCharArray() ); |
| } |
| |
| /** |
| * Converts an array of characters representing hexidecimal values into an |
| * array of bytes of those same values. The returned array will be half the |
| * length of the passed array, as it takes two characters to represent any |
| * given byte. An exception is thrown if the passed char array has an odd |
| * number of elements. |
| * |
| * @param data An array of characters containing hexidecimal digits |
| * @return A byte array containing binary data decoded from |
| * the supplied char array. |
| * @throws IllegalArgumentException if an odd number or illegal of characters |
| * is supplied |
| */ |
| public static byte[] decode(char[] data) throws IllegalArgumentException { |
| |
| int len = data.length; |
| |
| if ((len & 0x01) != 0) { |
| throw new IllegalArgumentException("Odd number of characters."); |
| } |
| |
| byte[] out = new byte[len >> 1]; |
| |
| // two characters form the hex value. |
| for (int i = 0, j = 0; j < len; i++) { |
| int f = toDigit(data[j], j) << 4; |
| j++; |
| f = f | toDigit(data[j], j); |
| j++; |
| out[i] = (byte) (f & 0xFF); |
| } |
| |
| return out; |
| } |
| |
| /** |
| * Converts a hexadecimal character to an integer. |
| * |
| * @param ch A character to convert to an integer digit |
| * @param index The index of the character in the source |
| * @return An integer |
| * @throws IllegalArgumentException if ch is an illegal hex character |
| */ |
| protected static int toDigit(char ch, int index) throws IllegalArgumentException { |
| int digit = Character.digit(ch, 16); |
| if (digit == -1) { |
| throw new IllegalArgumentException("Illegal hexadecimal charcter " + ch + " at index " + index); |
| } |
| return digit; |
| } |
| |
| |
| } |