XXTEA加密算法 for C#
时间: 2023-07-12 11:47:50 浏览: 187
XXTEA是一种简单有效的加密算法,下面是C#的实现:
```
using System;
namespace XXTEA
{
class XXTEA
{
private static uint DELTA = 0x9E3779B9;
private static int MX = 16;
private static uint[] ToUIntArray(byte[] data, bool includeLength)
{
int length = data.Length;
int n = (((length & 3) == 0) ? (length >> 2) : ((length >> 2) + 1));
uint[] result;
if (includeLength)
{
result = new uint[n + 1];
result[n] = (uint)length;
}
else
{
result = new uint[n];
}
for (int i = 0; i < length; i++)
{
result[i >> 2] |= (uint)(data[i] << ((i & 3) << 3));
}
return result;
}
private static byte[] ToByteArray(uint[] data, bool includeLength)
{
int n = data.Length << 2;
if (includeLength)
{
int m = (int)data[data.Length - 1];
n -= 4;
if ((m < n - 3) || (m > n))
{
return null;
}
n = m;
}
byte[] result = new byte[n];
for (int i = 0; i < n; i++)
{
result[i] = (byte)(data[i >> 2] >> ((i & 3) << 3));
}
return result;
}
private static uint[] Encrypt(uint[] data, uint[] key)
{
uint[] result = new uint[data.Length];
uint sum = 0;
uint y = data[0];
uint z = data[data.Length - 1];
uint a, b, c, d, e, f, k;
for (int i = 0; i < MX; i++)
{
sum += DELTA;
a = key[i % 4];
b = key[(i + 1) % 4];
c = key[(i + 2) % 4];
d = key[(i + 3) % 4];
e = y >> 5 ^ z << 2;
f = z >> 3 ^ y << 4;
k = sum ^ z ^ e;
y += k ^ a ^ (z << 1 | z >> 31) ;
z += k ^ b ^ (y << 4 | y >> 28) ;
}
result[0] = y;
result[data.Length - 1] = z;
for (int i = 1; i < data.Length - 1; i++)
{
sum += DELTA;
a = key[i % 4];
b = key[(i + 1) % 4];
c = key[(i + 2) % 4];
d = key[(i + 3) % 4];
e = result[i - 1] >> 5 ^ result[i + 1] << 2;
f = result[i + 1] >> 3 ^ result[i - 1] << 4;
k = sum ^ result[i - 1] ^ e;
result[i] = result[i] + (k ^ b ^ (result[i - 1] << 1 | result[i - 1] >> 31)) ;
result[i] = result[i] + (k ^ c ^ (result[i + 1] << 4 | result[i + 1] >> 28)) ;
}
return result;
}
private static uint[] Decrypt(uint[] data, uint[] key)
{
uint[] result = new uint[data.Length];
uint sum = (uint)(DELTA * MX);
uint y = data[0];
uint z = data[data.Length - 1];
uint a, b, c, d, e, f, k;
for (int i = 0; i < MX; i++)
{
k = sum ^ z ^ (y << 1 | y >> 31) ;
z -= k ^ b ^ (y << 4 | y >> 28) ;
y -= k ^ a ^ (z << 1 | z >> 31) ;
sum -= DELTA;
a = key[i % 4];
b = key[(i + 1) % 4];
c = key[(i + 2) % 4];
d = key[(i + 3) % 4];
e = z >> 5 ^ y << 2;
f = y >> 3 ^ z << 4;
}
result[0] = y;
result[data.Length - 1] = z;
for (int i = 1; i < data.Length - 1; i++)
{
sum -= DELTA;
a = key[i % 4];
b = key[(i + 1) % 4];
c = key[(i + 2) % 4];
d = key[(i + 3) % 4];
e = result[i - 1] >> 5 ^ result[i + 1] << 2;
f = result[i + 1] >> 3 ^ result[i - 1] << 4;
k = sum ^ result[i - 1] ^ e;
result[i] = result[i] - (k ^ c ^ (result[i + 1] << 4 | result[i + 1] >> 28)) ;
result[i] = result[i] - (k ^ b ^ (result[i - 1] << 1 | result[i - 1] >> 31)) ;
}
return result;
}
public static byte[] Encrypt(byte[] data, byte[] key)
{
if ((data == null) || (data.Length == 0))
{
return data;
}
uint[] v = ToUIntArray(data, true);
uint[] k = ToUIntArray(key, false);
if (k.Length < 4)
{
uint[] keyTemp = new uint[4];
k.CopyTo(keyTemp, 0);
k = keyTemp;
}
return ToByteArray(Encrypt(v, k), false);
}
public static byte[] Decrypt(byte[] data, byte[] key)
{
if ((data == null) || (data.Length == 0))
{
return data;
}
uint[] v = ToUIntArray(data, false);
uint[] k = ToUIntArray(key, false);
if (k.Length < 4)
{
uint[] keyTemp = new uint[4];
k.CopyTo(keyTemp, 0);
k = keyTemp;
}
return ToByteArray(Decrypt(v, k), true);
}
}
}
```
这里提供了两个方法,一个是加密方法Encrypt,一个是解密方法Decrypt。它们都需要两个参数,一个是要加密或解密的数据,另一个是加密或解密所需要的密钥。注意,加密和解密所使用的密钥必须一致。
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