| /* |
| * Copyright (C) 2021 The Android Open Source Project |
| * |
| * 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 com.android.net.module.util; |
| |
| import androidx.annotation.Nullable; |
| |
| /** |
| * Hex utility functions. |
| * |
| * @hide |
| */ |
| public class HexDump { |
| private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 'A', 'B', 'C', 'D', 'E', 'F' }; |
| private static final char[] HEX_LOWER_CASE_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', |
| '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; |
| |
| /** |
| * Dump the hex string corresponding to the specified byte array. |
| * |
| * @param array byte array to be dumped. |
| */ |
| public static String dumpHexString(@Nullable byte[] array) { |
| if (array == null) return "(null)"; |
| return dumpHexString(array, 0, array.length); |
| } |
| |
| /** |
| * Dump the hex string corresponding to the specified byte array. |
| * |
| * @param array byte array to be dumped. |
| * @param offset the offset in array where dump should start. |
| * @param length the length of bytes to be dumped. |
| */ |
| public static String dumpHexString(@Nullable byte[] array, int offset, int length) { |
| if (array == null) return "(null)"; |
| StringBuilder result = new StringBuilder(); |
| |
| byte[] line = new byte[16]; |
| int lineIndex = 0; |
| |
| result.append("\n0x"); |
| result.append(toHexString(offset)); |
| |
| for (int i = offset; i < offset + length; i++) { |
| if (lineIndex == 16) { |
| result.append(" "); |
| |
| for (int j = 0; j < 16; j++) { |
| if (line[j] > ' ' && line[j] < '~') { |
| result.append(new String(line, j, 1)); |
| } else { |
| result.append("."); |
| } |
| } |
| |
| result.append("\n0x"); |
| result.append(toHexString(i)); |
| lineIndex = 0; |
| } |
| |
| byte b = array[i]; |
| result.append(" "); |
| result.append(HEX_DIGITS[(b >>> 4) & 0x0F]); |
| result.append(HEX_DIGITS[b & 0x0F]); |
| |
| line[lineIndex++] = b; |
| } |
| |
| if (lineIndex != 16) { |
| int count = (16 - lineIndex) * 3; |
| count++; |
| for (int i = 0; i < count; i++) { |
| result.append(" "); |
| } |
| |
| for (int i = 0; i < lineIndex; i++) { |
| if (line[i] > ' ' && line[i] < '~') { |
| result.append(new String(line, i, 1)); |
| } else { |
| result.append("."); |
| } |
| } |
| } |
| |
| return result.toString(); |
| } |
| |
| /** |
| * Convert a byte to an uppercase hex string. |
| * |
| * @param b the byte to be converted. |
| */ |
| public static String toHexString(byte b) { |
| return toHexString(toByteArray(b)); |
| } |
| |
| /** |
| * Convert a byte array to an uppercase hex string. |
| * |
| * @param array the byte array to be converted. |
| */ |
| public static String toHexString(byte[] array) { |
| return toHexString(array, 0, array.length, true); |
| } |
| |
| /** |
| * Convert a byte array to a hex string. |
| * |
| * @param array the byte array to be converted. |
| * @param upperCase whether the converted hex string should be uppercase or not. |
| */ |
| public static String toHexString(byte[] array, boolean upperCase) { |
| return toHexString(array, 0, array.length, upperCase); |
| } |
| |
| /** |
| * Convert a byte array to hex string. |
| * |
| * @param array the byte array to be converted. |
| * @param offset the offset in array where conversion should start. |
| * @param length the length of bytes to be converted. |
| */ |
| public static String toHexString(byte[] array, int offset, int length) { |
| return toHexString(array, offset, length, true); |
| } |
| |
| /** |
| * Convert a byte array to hex string. |
| * |
| * @param array the byte array to be converted. |
| * @param offset the offset in array where conversion should start. |
| * @param length the length of bytes to be converted. |
| * @param upperCase whether the converted hex string should be uppercase or not. |
| */ |
| public static String toHexString(byte[] array, int offset, int length, boolean upperCase) { |
| char[] digits = upperCase ? HEX_DIGITS : HEX_LOWER_CASE_DIGITS; |
| char[] buf = new char[length * 2]; |
| |
| int bufIndex = 0; |
| for (int i = offset; i < offset + length; i++) { |
| byte b = array[i]; |
| buf[bufIndex++] = digits[(b >>> 4) & 0x0F]; |
| buf[bufIndex++] = digits[b & 0x0F]; |
| } |
| |
| return new String(buf); |
| } |
| |
| /** |
| * Convert an integer to hex string. |
| * |
| * @param i the integer to be converted. |
| */ |
| public static String toHexString(int i) { |
| return toHexString(toByteArray(i)); |
| } |
| |
| /** |
| * Convert a byte to byte array. |
| * |
| * @param b the byte to be converted. |
| */ |
| public static byte[] toByteArray(byte b) { |
| byte[] array = new byte[1]; |
| array[0] = b; |
| return array; |
| } |
| |
| /** |
| * Convert an integer to byte array. |
| * |
| * @param i the integer to be converted. |
| */ |
| public static byte[] toByteArray(int i) { |
| byte[] array = new byte[4]; |
| |
| array[3] = (byte) (i & 0xFF); |
| array[2] = (byte) ((i >> 8) & 0xFF); |
| array[1] = (byte) ((i >> 16) & 0xFF); |
| array[0] = (byte) ((i >> 24) & 0xFF); |
| |
| return array; |
| } |
| |
| private static int toByte(char c) { |
| if (c >= '0' && c <= '9') return (c - '0'); |
| if (c >= 'A' && c <= 'F') return (c - 'A' + 10); |
| if (c >= 'a' && c <= 'f') return (c - 'a' + 10); |
| |
| throw new RuntimeException("Invalid hex char '" + c + "'"); |
| } |
| |
| /** |
| * Convert a hex string to a byte array. |
| * |
| * @param hexString the string to be converted. |
| */ |
| public static byte[] hexStringToByteArray(String hexString) { |
| int length = hexString.length(); |
| byte[] buffer = new byte[length / 2]; |
| |
| for (int i = 0; i < length; i += 2) { |
| buffer[i / 2] = |
| (byte) ((toByte(hexString.charAt(i)) << 4) | toByte(hexString.charAt(i + 1))); |
| } |
| |
| return buffer; |
| } |
| |
| /** |
| * Convert a byte to hex string and append it to StringBuilder. |
| * |
| * @param sb StringBuilder instance. |
| * @param b the byte to be converted. |
| * @param upperCase whether the converted hex string should be uppercase or not. |
| */ |
| public static StringBuilder appendByteAsHex(StringBuilder sb, byte b, boolean upperCase) { |
| char[] digits = upperCase ? HEX_DIGITS : HEX_LOWER_CASE_DIGITS; |
| sb.append(digits[(b >> 4) & 0xf]); |
| sb.append(digits[b & 0xf]); |
| return sb; |
| } |
| } |