| /* |
| * 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.apache.catalina.util; |
| |
| import java.io.ByteArrayOutputStream; |
| |
| /** |
| * Library of utility methods useful in dealing with converting byte arrays |
| * to and from strings of hexadecimal digits. |
| * |
| * Note: this package has been stripped of its localization capabilities, |
| * to lessen library dependencies and increase portability. |
| * - ARJ, 4/04 |
| * |
| * @author Craig R. McClanahan |
| * @since 2.3 |
| */ |
| |
| public final class HexUtils |
| { |
| // Code from Ajp11, from Apache's JServ |
| |
| // Table for HEX to DEC byte translation |
| static final int[] DEC = |
| { |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 00, 01, 02, 03, 04, 05, 06, 07, 8, 9, -1, -1, -1, -1, -1, -1, |
| -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| }; |
| |
| /** |
| * Convert a String of hexadecimal digits into the corresponding |
| * byte array by encoding each two hexadecimal digits as a byte. |
| * |
| * @param digits Hexadecimal digits representation |
| * |
| * @exception IllegalArgumentException if an invalid hexadecimal digit |
| * is found, or the input string contains an odd number of hexadecimal |
| * digits |
| */ |
| public static byte[] convert(String digits) |
| { |
| |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(); |
| for (int i = 0; i < digits.length(); i += 2) |
| { |
| char c1 = digits.charAt(i); |
| if ((i+1) >= digits.length()) |
| throw new IllegalArgumentException |
| ("Odd number of hexadecimal digits"); |
| char c2 = digits.charAt(i + 1); |
| byte b = 0; |
| if ((c1 >= '0') && (c1 <= '9')) |
| b += (c1 - '0') * 16; |
| else if ((c1 >= 'a') && (c1 <= 'f')) |
| b += (c1 - 'a' + 10) * 16; |
| else if ((c1 >= 'A') && (c1 <= 'F')) |
| b += (c1 - 'A' + 10) * 16; |
| else |
| throw new IllegalArgumentException |
| ("Bad hexadecimal digit"); |
| if ((c2 >= '0') && (c2 <= '9')) |
| b += c2 - '0'; |
| else if ((c2 >= 'a') && (c2 <= 'f')) |
| b += c2 - 'a' + 10; |
| else if ((c2 >= 'A') && (c2 <= 'F')) |
| b += c2 - 'A' + 10; |
| else |
| throw new IllegalArgumentException |
| ("Bad hexadecimal digit"); |
| baos.write(b); |
| } |
| return baos.toByteArray(); |
| |
| } |
| |
| |
| /** |
| * Convert a byte array into a printable format containing a |
| * String of hexadecimal digit characters (two per byte). |
| * |
| * @param bytes Byte array representation |
| */ |
| public static String convert(byte[] bytes) |
| { |
| |
| StringBuffer sb = new StringBuffer(bytes.length * 2); |
| for (int i = 0; i < bytes.length; i++) |
| { |
| sb.append(convertDigit(bytes[i] >> 4)); |
| sb.append(convertDigit(bytes[i] & 0x0f)); |
| } |
| return sb.toString(); |
| |
| } |
| |
| /** |
| * Convert 4 hex digits to an int, and return the number of converted |
| * bytes. |
| * |
| * @param hex Byte array containing exactly four hexadecimal digits |
| * |
| * @exception IllegalArgumentException if an invalid hexadecimal digit |
| * is included |
| */ |
| public static int convert2Int( byte[] hex ) |
| { |
| // Code from Ajp11, from Apache's JServ |
| |
| // assert b.length==4 |
| // assert valid data |
| int len; |
| if(hex.length < 4 ) return 0; |
| if( DEC[hex[0]]<0 ) |
| throw new IllegalArgumentException("Bad hexadecimal digit"); |
| len = DEC[hex[0]]; |
| len = len << 4; |
| if( DEC[hex[1]]<0 ) |
| throw new IllegalArgumentException("Bad hexadecimal digit"); |
| len += DEC[hex[1]]; |
| len = len << 4; |
| if( DEC[hex[2]]<0 ) |
| throw new IllegalArgumentException("Bad hexadecimal digit"); |
| len += DEC[hex[2]]; |
| len = len << 4; |
| if( DEC[hex[3]]<0 ) |
| throw new IllegalArgumentException("Bad hexadecimal digit"); |
| len += DEC[hex[3]]; |
| return len; |
| } |
| |
| /** |
| * [Private] Convert the specified value (0 .. 15) to the corresponding |
| * hexadecimal digit. |
| * |
| * @param value Value to be converted |
| */ |
| private static char convertDigit(int value) |
| { |
| |
| value &= 0x0f; |
| if (value >= 10) |
| { |
| return (char) (value - 10 + 'a'); |
| } |
| return (char) (value + '0'); |
| } |
| |
| } |