| /* |
| * 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.directory.shared.asn1; |
| |
| |
| import org.apache.directory.shared.i18n.I18n; |
| |
| |
| /** |
| * Hex encoder and decoder. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class Hex implements BinaryEncoder, BinaryDecoder |
| { |
| /** 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' }; |
| |
| |
| /** |
| * 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 DecoderException Thrown if an odd number or illegal of characters is supplied |
| */ |
| public static byte[] decodeHex( char[] data ) throws DecoderException |
| { |
| int len = data.length; |
| |
| if ( ( len & 0x01 ) != 0 ) |
| { |
| throw new DecoderException( I18n.err( I18n.ERR_00013_ODD_NUM_OF_CHARS ) ); |
| } |
| |
| 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 |= 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 DecoderException Thrown if ch is an illegal hex character |
| */ |
| private static int toDigit( char ch, int index ) throws DecoderException |
| { |
| int digit = Character.digit( ch, 16 ); |
| |
| if ( digit == -1 ) |
| { |
| throw new DecoderException( I18n.err( I18n.ERR_00014_ILLEGAL_HEX_CHAR, ch, index ) ); |
| } |
| |
| return digit; |
| } |
| |
| |
| /** |
| * 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 a byte[] to convert to Hex characters |
| * @return A char[] containing hexidecimal characters |
| */ |
| public static char[] encodeHex( 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 DecoderException Thrown if an odd number of characters is supplied to this |
| * function |
| * @see #decodeHex(char[]) |
| */ |
| public byte[] decode( byte[] array ) throws DecoderException |
| { |
| return decodeHex( new String( array ).toCharArray() ); |
| } |
| |
| |
| /** |
| * Converts a String or 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 String or 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 object A String or, an array of character bytes containing |
| * hexadecimal digits |
| * @return A byte array containing binary data decoded from the supplied |
| * byte array (representing characters). |
| * @throws DecoderException Thrown if an odd number of characters is supplied to this |
| * function or the object is not a String or char[] |
| * @see #decodeHex(char[]) |
| */ |
| public Object decode( Object object ) throws DecoderException |
| { |
| try |
| { |
| char[] charArray = null; |
| |
| if ( object instanceof String ) |
| { |
| charArray = ( ( String ) object ).toCharArray(); |
| } |
| else |
| { |
| charArray = ( char[] ) object; |
| } |
| |
| return decodeHex( charArray ); |
| } |
| catch ( ClassCastException e ) |
| { |
| throw new DecoderException( e.getMessage() ); |
| } |
| } |
| |
| |
| /** |
| * Converts an array of bytes into an array of bytes for the 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 array a byte[] to convert to Hex characters |
| * @return A byte[] containing the bytes of the hexidecimal characters |
| * @see #encodeHex(byte[]) |
| */ |
| public byte[] encode( byte[] array ) |
| { |
| return new String( encodeHex( array ) ).getBytes(); |
| } |
| |
| |
| /** |
| * Converts a String or 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 String or array, as it |
| * takes two characters to represent any given byte. |
| * |
| * @param object a String, or byte[] to convert to Hex characters |
| * @return A char[] containing hexidecimal characters |
| * @throws org.apache.directory.shared.asn1.EncoderException Thrown if the given object is not a String or byte[] |
| * @see #encodeHex(byte[]) |
| */ |
| public Object encode( Object object ) throws EncoderException |
| { |
| try |
| { |
| byte[] byteArray = null; |
| |
| if ( object instanceof String ) |
| { |
| byteArray = ( ( String ) object ).getBytes(); |
| } |
| else |
| { |
| byteArray = ( byte[] ) object; |
| } |
| |
| return encodeHex( byteArray ); |
| } |
| catch ( ClassCastException e ) |
| { |
| throw new EncoderException( e.getMessage() ); |
| } |
| } |
| } |