session-android/src/org/thoughtcrime/securesms/util/Hex.java
2014-11-12 15:42:43 -08:00

139 lines
3.9 KiB
Java

/**
* Copyright (C) 2011 Whisper Systems
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.thoughtcrime.securesms.util;
import java.io.IOException;
/**
* Utility for generating hex dumps.
*/
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 toStringCondensed(byte[] bytes) {
StringBuffer buf = new StringBuffer();
for (int i=0;i<bytes.length;i++) {
appendHexChar(buf, bytes[i]);
}
return buf.toString();
}
public static byte[] fromStringCondensed(String encoded) throws IOException {
final char[] data = encoded.toCharArray();
final int len = data.length;
if ((len & 0x01) != 0) {
throw new IOException("Odd number of characters.");
}
final byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++) {
int f = Character.digit(data[j], 16) << 4;
j++;
f = f | Character.digit(data[j], 16);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
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]);
}
}