1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /**
  25  * Utility class containing conversions between strings, arrays, and numeric
  26  * values.
  27  */
  28 
  29 import java.math.BigInteger;
  30 
  31 public class Convert {
  32 
  33     public static String byteArrayToHexString(byte[] arr) {
  34         StringBuilder result = new StringBuilder();
  35         for (int i = 0; i < arr.length; ++i) {
  36             byte curVal = arr[i];
  37             result.append(Character.forDigit(curVal >> 4 & 0xF, 16));
  38             result.append(Character.forDigit(curVal & 0xF, 16));
  39         }
  40         return result.toString();
  41     }
  42 
  43     public static byte[] byteToByteArray(byte v, int length) {
  44         byte[] result = new byte[length];
  45         result[0] = v;
  46         return result;
  47     }
  48 
  49     public static byte[] hexStringToByteArray(String str) {
  50         byte[] result = new byte[str.length() / 2];
  51         for (int i = 0; i < result.length; i++) {
  52             result[i] = (byte) Character.digit(str.charAt(2 * i), 16);
  53             result[i] <<= 4;
  54             result[i] += Character.digit(str.charAt(2 * i + 1), 16);
  55         }
  56         return result;
  57     }
  58 
  59     public static
  60     BigInteger hexStringToBigInteger(boolean clearHighBit, String str) {
  61         BigInteger result = BigInteger.ZERO;
  62         for (int i = 0; i < str.length() / 2; i++) {
  63             int curVal = Character.digit(str.charAt(2 * i), 16);
  64             curVal <<= 4;
  65             curVal += Character.digit(str.charAt(2 * i + 1), 16);
  66             if (clearHighBit && i == str.length() / 2 - 1) {
  67                 curVal &= 0x7F;
  68             }
  69             result = result.add(BigInteger.valueOf(curVal).shiftLeft(8 * i));
  70         }
  71         return result;
  72     }
  73 }
  74 
  75