| /* |
| * 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.shiro.codec; |
| |
| /** |
| * <a href="http://en.wikipedia.org/wiki/Hexadecimal">Hexadecimal</a> encoder and decoder. |
| * <p/> |
| * This class was borrowed from Apache Commons Codec SVN repository (rev. {@code 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 Shiro user to depend on the commons-codec.jar |
| * <p/> |
| * As per the Apache 2.0 license, the original copyright notice and all author and copyright information have |
| * remained in tact. |
| * |
| * @see <a href="http://en.wikipedia.org/wiki/Hexadecimal">Wikipedia: Hexadecimal</a> |
| * @since 0.9 |
| */ |
| 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' |
| }; |
| |
| /** |
| * Encodes the specified byte array to a character array and then returns that character array |
| * as a String. |
| * |
| * @param bytes the byte array to Hex-encode. |
| * @return A String representation of the resultant hex-encoded char array. |
| */ |
| 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 hexadecimal 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 hexadecimal 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 hexadecimal 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 hexadecimal 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); |
| } |
| |
| /** |
| * Converts the specified Hex-encoded String into a raw byte array. This is a |
| * convenience method that merely delegates to {@link #decode(char[])} using the |
| * argument's hex.toCharArray() value. |
| * |
| * @param hex a Hex-encoded String. |
| * @return A byte array containing binary data decoded from the supplied String's char array. |
| */ |
| public static byte[] decode(String hex) { |
| return decode(hex.toCharArray()); |
| } |
| |
| /** |
| * Converts an array of characters representing hexadecimal 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 hexadecimal 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 character " + ch + " at index " + index); |
| } |
| return digit; |
| } |
| |
| |
| } |