/** * Copyright (C) 2013 Open WhisperSystems * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.whispersystems.textsecuregcm.util; /** * Utility for generating hex dumps a la hexl-mode in emacs. */ public class Hex { private final static int HEX_DIGITS_START = 10; private final static int ASCII_TEXT_START = HEX_DIGITS_START + (16*2 + (16/2)); final static String EOL = System.getProperty("line.separator"); private final static char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; public static String toString(byte[] bytes) { return toString(bytes, 0, bytes.length); } public static String toString(byte[] bytes, int offset, int length) { StringBuffer buf = new StringBuffer(); for (int i = 0; i < length; i++) { appendHexChar(buf, bytes[offset + i]); buf.append(' '); } return buf.toString(); } public static String dump(byte[] bytes) { return dump(bytes, 0, bytes.length); } public static String dump(byte[] bytes, int offset, int length) { StringBuffer buf = new StringBuffer(); int lines = ((length - 1) / 16) + 1; int lineOffset; int lineLength; for (int i = 0; i < lines; i++) { lineOffset = (i * 16) + offset; lineLength = Math.min(16, (length - (i * 16))); appendDumpLine(buf, i, bytes, lineOffset, lineLength); buf.append(EOL); } return buf.toString(); } private static void appendDumpLine(StringBuffer buf, int line, byte[] bytes, int lineOffset, int lineLength) { buf.append(HEX_DIGITS[(line >> 28) & 0xf]); buf.append(HEX_DIGITS[(line >> 24) & 0xf]); buf.append(HEX_DIGITS[(line >> 20) & 0xf]); buf.append(HEX_DIGITS[(line >> 16) & 0xf]); buf.append(HEX_DIGITS[(line >> 12) & 0xf]); buf.append(HEX_DIGITS[(line >> 8) & 0xf]); buf.append(HEX_DIGITS[(line >> 4) & 0xf]); buf.append(HEX_DIGITS[(line ) & 0xf]); buf.append(": "); for (int i = 0; i < 16; i++) { int idx = i + lineOffset; if (i < lineLength) { int b = bytes[idx]; appendHexChar(buf, b); } else { buf.append(" "); } if ((i % 2) == 1) { buf.append(' '); } } for (int i = 0; i < 16 && i < lineLength; i++) { int idx = i + lineOffset; int b = bytes[idx]; if (b >= 0x20 && b <= 0x7e) { buf.append((char)b); } else { buf.append('.'); } } } private static void appendHexChar(StringBuffer buf, int b) { buf.append(HEX_DIGITS[(b >> 4) & 0xf]); buf.append(HEX_DIGITS[b & 0xf]); } }