com.github.downgoon.jresty.commons.security.XXTEACodec Maven / Gradle / Ivy
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package com.github.downgoon.jresty.commons.security;
/**
* XXTEA 加密/解密
* */
public class XXTEACodec {
public static byte[] encrypt(byte[] data, byte[] key) {
if (data.length == 0) {
return data;
}
return toByteArray(encrypt(toIntArray(data, true), toIntArray(key, false)), false);
}
public static byte[] decrypt(byte[] data, byte[] key) {
if (data.length == 0) {
return data;
}
return toByteArray(decrypt(toIntArray(data, false), toIntArray(key, false)), true);
}
public static int[] encrypt(int[] v, int[] k) {
int n = v.length - 1;
if (n < 1) {
return v;
}
if (k.length < 4) {
int[] key = new int[4];
System.arraycopy(k, 0, key, 0, k.length);
k = key;
}
int z = v[n], y = v[0], delta = 0x9E3779B9, sum = 0, e;
int p, q = 6 + 52 / (n + 1);
while (q-- > 0) {
sum = sum + delta;
e = sum >>> 2 & 3;
for (p = 0; p < n; p++) {
y = v[p + 1];
z = v[p] += (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
}
y = v[0];
z = v[n] += (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
}
return v;
}
public static int[] decrypt(int[] v, int[] k) {
int n = v.length - 1;
if (n < 1) {
return v;
}
if (k.length < 4) {
int[] key = new int[4];
System.arraycopy(k, 0, key, 0, k.length);
k = key;
}
int z = v[n], y = v[0], delta = 0x9E3779B9, sum, e;
int p, q = 6 + 52 / (n + 1);
sum = q * delta;
while (sum != 0) {
e = sum >>> 2 & 3;
for (p = n; p > 0; p--) {
z = v[p - 1];
y = v[p] -= (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
}
z = v[n];
y = v[0] -= (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
sum = sum - delta;
}
return v;
}
private static int[] toIntArray(byte[] data, boolean includeLength) {
int n = (((data.length & 3) == 0) ? (data.length >>> 2) : ((data.length >>> 2) + 1));
int[] result;
if (includeLength) {
result = new int[n + 1];
result[n] = data.length;
} else {
result = new int[n];
}
n = data.length;
for (int i = 0; i < n; i++) {
result[i >>> 2] |= (0x000000ff & data[i]) << ((i & 3) << 3);
}
return result;
}
private static byte[] toByteArray(int[] data, boolean includeLength) {
int n = data.length << 2;
if (includeLength) {
int m = data[data.length - 1];
if (m > n) {
return null;
} else {
n = m;
}
}
byte[] result = new byte[n];
for (int i = 0; i < n; i++) {
result[i] = (byte) ((data[i >>> 2] >>> ((i & 3) << 3)) & 0xff);
}
return result;
}
}