c++ 通过XOR自己实现一个对称分组加密算法

自己编写基于XOR（异或）操作的对称加密和解密的算法实现方法

#include
#include
using namespace std;

#define XOR_BLOCK 8

void PrintHex(const unsigned char* data, int size) {
    for (int i = 0; i < size; ++i) {
        printf("%02x", data[i]);
    }
    printf("\n");
}

int XorCipher(const unsigned char* data, int data_size,
    unsigned char *out,
    const unsigned char *pass,
    int pass_size)
{
    static const char iv[] = "abcdefgh";
    unsigned long long p = *(unsigned long long*)iv;  // 初始化秘钥

    // 处理秘钥并与初始化向量异或
    for (int i = 0; i < pass_size; i += XOR_BLOCK)
    {
        unsigned long long tmp = 0;
        int size = XOR_BLOCK;
        if (pass_size - i < XOR_BLOCK)
        {
            size = pass_size - i;
        }
        memcpy(&tmp, (pass + i), size);
        p = (p ^ tmp);  // 更新p
    }

    // 数据源转换成8字节数据类型
    auto d = (unsigned long long*)data;
    // 输出数据
    auto o = (unsigned long long*) out;
    
    // 数据分组处理
    int i = 0;
    for (; i < data_size / XOR_BLOCK; i++)
    {
        o[i] = (d[i] ^ p);  // XOR异或运算
    }

    // 处理补充数据（不足8字节时）
    int mod = data_size % XOR_BLOCK;
    if (mod != 0)
    {
        unsigned long long tmp = 0;
        memcpy(&tmp, (d + i), mod);
        o[i] = (tmp ^ p);
    }

    return data_size;  // 返回加解密后的数据大小
}

int main(int argc, char* argv[])
{
    unsigned char data[] = "测试加解密数据TEST123测试秘钥";
    unsigned char out[1024] = { 0 };
    unsigned char out2[1024] = { 0 };
    unsigned char pass[] = "12345678";
    int pass_size = strlen((char*)pass);

    int len = XorCipher(data, sizeof(data) - 1, out, pass, pass_size);  // 加密
    cout << "Encrypted size: " << len << " | Encrypted data: ";
    PrintHex(out, len);

    len = XorCipher(out, len, out2, pass, pass_size);  // 解密
    cout << "Decrypted size: " << len << " | Decrypted data: ";
    PrintHex(out2, len);

    return 0;
}

注意，这个示例代码只是简单的异或加解密，而实际生产环境中需要更加安全的算法（如AES）来处理敏感数据。