xxtea_uint

在引用和引用[3]中提到，xxtea_uint是指待加密/解密的32位数据块的类型。在XXTEA算法中，加密和解密过程都是对32位数据块数组中的每个元素进行操作，因此xxtea_uint被定义为32位的无符号整数类型。在引用的示例代码中，加密和解密函数xxtea_encrypt和xxtea_decrypt的参数中都使用了xxtea_uint类型的数据块数组。<span class="em">1</span><span class="em">2</span><span class="em">3</span>

相关问题

xxtea 单片机C语言

以下是XXTEA算法的单片机C语言实现示例：

#include <stdint.h>
#include <string.h>

void xxtea_encode(uint32_t *v, uint32_t len, uint32_t *key) {
    uint32_t i, v0, v1, sum = 0, delta = 0x9E3779B9;
    uint32_t k[4];
    memcpy(k, key, 16);
    for (i = 0; i < len; i++) {
        v0 = v[i];
        v1 = v[(i + 1) % len];
        sum += delta;
        v0 += ((v1 << 4) + k[0]) ^ (v1 + sum) ^ ((v1 >> 5) + k[1]);
        v1 += ((v0 << 4) + k[2]) ^ (v0 + sum) ^ ((v0 >> 5) + k[3]);
        v[i] = v0;
        v[(i + 1) % len] = v1;
    }
}

void xxtea_decode(uint32_t *v, uint32_t len, uint32_t *key) {
    uint32_t i, v0, v1, sum = 0xC6EF3720, delta = 0x9E3779B9;
    uint32_t k[4];
    memcpy(k, key, 16);
    for (i = len - 1; i > 0; i--) {
        v1 = v[i];
        v0 = v[(i - 1) % len];
        v1 -= ((v0 << 4) + k[2]) ^ (v0 + sum) ^ ((v0 >> 5) + k[3]);
        v0 -= ((v1 << 4) + k[0]) ^ (v1 + sum) ^ ((v1 >> 5) + k[1]);
        sum -= delta;
        v[i] = v1;
        v[(i - 1) % len] = v0;
    }
}

此代码实现了XXTEA算法的加密和解密操作，其中 `xxtea_encode` 函数用于加密操作，`xxtea_decode` 函数用于解密操作，两个函数的参数分别为：待加密/解密数据的指针 `v`，数据长度 `len`，密钥的指针 `key`。在使用时，需要将待加密/解密的数据转换为 `uint32_t` 类型的数组，且数据长度必须是 `uint32_t` 类型的整数倍。

XXTEA加密算法 for C#

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。