com.wavemaker.commons.util.SystemUtils Maven / Gradle / Ivy
/**
* Copyright (C) 2020 WaveMaker, Inc.
*
* 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.wavemaker.commons.util;
/**
* @author Simon Toens
*/
public abstract class SystemUtils {
private static final byte[] KEY = { 12, 7, 28, 127, 97, 69, 77, 122, 11 };
private static final String ENCRYPTED_PREFIX = "wm_-+";
private static final String ENCRYPTED_SUFFIX = "==wm-_";
private SystemUtils() {
}
public static String encrypt(String s) {
s = ENCRYPTED_PREFIX + s + ENCRYPTED_SUFFIX;
StringBuilder rtn = new StringBuilder(s.length());
byte[] bytes = s.getBytes();
for (int i = 0; i < bytes.length; i++) {
rtn.append(encrypt(bytes[i], KEY[i % KEY.length]));
}
return rtn.toString();
}
public static String encryptIfNotEncrypted(String s) {
return isEncrypted(s) ? s : encrypt(s);
}
public static String decrypt(String s) {
return decrypt(s, true);
}
public static String decryptIfEncrypted(String s) {
return isEncrypted(s) ? decrypt(s) : s;
}
private static String decrypt(String s, boolean removeMarkers) {
byte[] rtn = new byte[s.length() / 2];
int j = 0;
for (int i = 0; i < s.length(); i += 2) {
String hex = s.substring(i, i + 2);
rtn[j] = (byte) (Integer.parseInt(hex, 16) ^ KEY[j % KEY.length]);
j++;
}
String d = new String(rtn);
if (removeMarkers && hasMarkers(d)) {
return d.substring(ENCRYPTED_PREFIX.length(), d.length() - ENCRYPTED_SUFFIX.length());
}
return d;
}
public static boolean isEncrypted(String s) {
if (s == null) {
return false;
}
try {
String d = decrypt(s, false);
return hasMarkers(d);
} catch (RuntimeException ex) {
return false;
}
}
private static boolean hasMarkers(String s) {
return s.startsWith(ENCRYPTED_PREFIX) && s.endsWith(ENCRYPTED_SUFFIX);
}
private static String encrypt(byte b, byte key) {
b = (byte) (b ^ key);
String rtn = Integer.toHexString(b);
if (rtn.length() == 1) {
rtn = "0" + rtn;
}
return rtn;
}
/**
* Converts byte array to long, assuming the bytes are unsigned.
*/
public static long getUnsignedValue(byte[] bytes) {
long rtn = 0;
for (int i = 0; i < bytes.length; i++) {
byte b = bytes[i];
boolean isSignBitSet = (b & 128) == 128;
if (isSignBitSet) {
// unset sign bit before 'or'ing with rtn
b = (byte) (b & 127);
}
rtn |= b;
if (isSignBitSet) {
// add 'sign' bit as regular bit
rtn |= 128;
}
if (i < bytes.length - 1) {
rtn <<= 8; // 8 because unsigned
}
}
return rtn;
}
public static Throwable getRootException(Throwable th) {
while (th.getCause() != null) {
th = th.getCause();
}
return th;
}
/**
* Get the native line separator.
*
* @return The property line.separator as a String.
*/
public static String getLineBreak() {
return System.lineSeparator();
}
}