算法难度：⭐⭐⭐
爆破难度：⭐
信息收集
运行情况：
查壳与脱壳：
无壳
调试分析
直接IDA打开，找到窗口函数，0x111，3eb分支：
首先是获取输入的两个值
然后这里使用UserName计算了一个数组出来
然后就是计算比较环节，这里很奇怪，这里把数组的地址转成十进制，变成字符串，然后去计算校验码，合着刚刚算的一大堆没用是吧！！！
校验码的计算：
首先是第一段循环：循环100h次，计算一个数组，数组有100h字节
然后是第二段循环：
给eax赋初值FFFFFFFFh，然后取一个字节，和ff异或，然后eax右移8位，和数组中的一个4字节异或
emmm，256个成员的数组，全F的初值，每次循环位移8位，这不就是CRC32算法嘛
注册机
程序跑起来之后，在生成crc32的数组之后断下来，复制出来直接用，就不用再手动计算数组了
注册码生成算法：
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
unsigned char arr1[8] = {
0x63, 0x72, 0x61, 0x63, 0x6B, 0x6D, 0x65, 0x00
};
unsigned char arr2[67] = {
0x36, 0x35, 0x37, 0x75, 0x74, 0x68, 0x75, 0x74, 0x64, 0x75, 0x65, 0x68, 0x64, 0x68, 0x64, 0x68,
0x64, 0x2C, 0x6C, 0x6A, 0x68, 0x67, 0x73, 0x34, 0x73, 0x67, 0x66, 0x34, 0x73, 0x35, 0x73, 0x35,
0x67, 0x73, 0x35, 0x73, 0x67, 0x35, 0x67, 0x34, 0x35, 0x73, 0x34, 0x67, 0x35, 0x64, 0x67, 0x79,
0x73, 0x68, 0x73, 0x74, 0x65, 0x5D, 0x5B, 0x67, 0x66, 0x5D, 0x66, 0x67, 0x5D, 0x66, 0x5D, 0x64,
0x5D, 0x00, 0x00
};
//------------------------------------------------------------
//----------- Created with 010 Editor -----------
//------ www.sweetscape.com/010editor/ ------
//
// File : Untitled1
// Address : 0 (0x0)
// Size : 1024 (0x400)
//------------------------------------------------------------
unsigned char hexData[1024] = {
0x00, 0x00, 0x00, 0x00, 0x96, 0x30, 0x07, 0x77, 0x2C, 0x61, 0x0E, 0xEE, 0xBA, 0x51, 0x09, 0x99,
0x19, 0xC4, 0x6D, 0x07, 0x8F, 0xF4, 0x6A, 0x70, 0x35, 0xA5, 0x63, 0xE9, 0xA3, 0x95, 0x64, 0x9E,
0x32, 0x88, 0xDB, 0x0E, 0xA4, 0xB8, 0xDC, 0x79, 0x1E, 0xE9, 0xD5, 0xE0, 0x88, 0xD9, 0xD2, 0x97,
0x2B, 0x4C, 0xB6, 0x09, 0xBD, 0x7C, 0xB1, 0x7E, 0x07, 0x2D, 0xB8, 0xE7, 0x91, 0x1D, 0xBF, 0x90,
0x64, 0x10, 0xB7, 0x1D, 0xF2, 0x20, 0xB0, 0x6A, 0x48, 0x71, 0xB9, 0xF3, 0xDE, 0x41, 0xBE, 0x84,
0x7D, 0xD4, 0xDA, 0x1A, 0xEB, 0xE4, 0xDD, 0x6D, 0x51, 0xB5, 0xD4, 0xF4, 0xC7, 0x85, 0xD3, 0x83,
0x56, 0x98, 0x6C, 0x13, 0xC0, 0xA8, 0x6B, 0x64, 0x7A, 0xF9, 0x62, 0xFD, 0xEC, 0xC9, 0x65, 0x8A,
0x4F, 0x5C, 0x01, 0x14, 0xD9, 0x6C, 0x06, 0x63, 0x63, 0x3D, 0x0F, 0xFA, 0xF5, 0x0D, 0x08, 0x8D,
0xC8, 0x20, 0x6E, 0x3B, 0x5E, 0x10, 0x69, 0x4C, 0xE4, 0x41, 0x60, 0xD5, 0x72, 0x71, 0x67, 0xA2,
0xD1, 0xE4, 0x03, 0x3C, 0x47, 0xD4, 0x04, 0x4B, 0xFD, 0x85, 0x0D, 0xD2, 0x6B, 0xB5, 0x0A, 0xA5,
0xFA, 0xA8, 0xB5, 0x35, 0x6C, 0x98, 0xB2, 0x42, 0xD6, 0xC9, 0xBB, 0xDB, 0x40, 0xF9, 0xBC, 0xAC,
0xE3, 0x6C, 0xD8, 0x32, 0x75, 0x5C, 0xDF, 0x45, 0xCF, 0x0D, 0xD6, 0xDC, 0x59, 0x3D, 0xD1, 0xAB,
0xAC, 0x30, 0xD9, 0x26, 0x3A, 0x00, 0xDE, 0x51, 0x80, 0x51, 0xD7, 0xC8, 0x16, 0x61, 0xD0, 0xBF,
0xB5, 0xF4, 0xB4, 0x21, 0x23, 0xC4, 0xB3, 0x56, 0x99, 0x95, 0xBA, 0xCF, 0x0F, 0xA5, 0xBD, 0xB8,
0x9E, 0xB8, 0x02, 0x28, 0x08, 0x88, 0x05, 0x5F, 0xB2, 0xD9, 0x0C, 0xC6, 0x24, 0xE9, 0x0B, 0xB1,
0x87, 0x7C, 0x6F, 0x2F, 0x11, 0x4C, 0x68, 0x58, 0xAB, 0x1D, 0x61, 0xC1, 0x3D, 0x2D, 0x66, 0xB6,
0x90, 0x41, 0xDC, 0x76, 0x06, 0x71, 0xDB, 0x01, 0xBC, 0x20, 0xD2, 0x98, 0x2A, 0x10, 0xD5, 0xEF,
0x89, 0x85, 0xB1, 0x71, 0x1F, 0xB5, 0xB6, 0x06, 0xA5, 0xE4, 0xBF, 0x9F, 0x33, 0xD4, 0xB8, 0xE8,
0xA2, 0xC9, 0x07, 0x78, 0x34, 0xF9, 0x00, 0x0F, 0x8E, 0xA8, 0x09, 0x96, 0x18, 0x98, 0x0E, 0xE1,
0xBB, 0x0D, 0x6A, 0x7F, 0x2D, 0x3D, 0x6D, 0x08, 0x97, 0x6C, 0x64, 0x91, 0x01, 0x5C, 0x63, 0xE6,
0xF4, 0x51, 0x6B, 0x6B, 0x62, 0x61, 0x6C, 0x1C, 0xD8, 0x30, 0x65, 0x85, 0x4E, 0x00, 0x62, 0xF2,
0xED, 0x95, 0x06, 0x6C, 0x7B, 0xA5, 0x01, 0x1B, 0xC1, 0xF4, 0x08, 0x82, 0x57, 0xC4, 0x0F, 0xF5,
0xC6, 0xD9, 0xB0, 0x65, 0x50, 0xE9, 0xB7, 0x12, 0xEA, 0xB8, 0xBE, 0x8B, 0x7C, 0x88, 0xB9, 0xFC,
0xDF, 0x1D, 0xDD, 0x62, 0x49, 0x2D, 0xDA, 0x15, 0xF3, 0x7C, 0xD3, 0x8C, 0x65, 0x4C, 0xD4, 0xFB,
0x58, 0x61, 0xB2, 0x4D, 0xCE, 0x51, 0xB5, 0x3A, 0x74, 0x00, 0xBC, 0xA3, 0xE2, 0x30, 0xBB, 0xD4,
0x41, 0xA5, 0xDF, 0x4A, 0xD7, 0x95, 0xD8, 0x3D, 0x6D, 0xC4, 0xD1, 0xA4, 0xFB, 0xF4, 0xD6, 0xD3,
0x6A, 0xE9, 0x69, 0x43, 0xFC, 0xD9, 0x6E, 0x34, 0x46, 0x88, 0x67, 0xAD, 0xD0, 0xB8, 0x60, 0xDA,
0x73, 0x2D, 0x04, 0x44, 0xE5, 0x1D, 0x03, 0x33, 0x5F, 0x4C, 0x0A, 0xAA, 0xC9, 0x7C, 0x0D, 0xDD,
0x3C, 0x71, 0x05, 0x50, 0xAA, 0x41, 0x02, 0x27, 0x10, 0x10, 0x0B, 0xBE, 0x86, 0x20, 0x0C, 0xC9,
0x25, 0xB5, 0x68, 0x57, 0xB3, 0x85, 0x6F, 0x20, 0x09, 0xD4, 0x66, 0xB9, 0x9F, 0xE4, 0x61, 0xCE,
0x0E, 0xF9, 0xDE, 0x5E, 0x98, 0xC9, 0xD9, 0x29, 0x22, 0x98, 0xD0, 0xB0, 0xB4, 0xA8, 0xD7, 0xC7,
0x17, 0x3D, 0xB3, 0x59, 0x81, 0x0D, 0xB4, 0x2E, 0x3B, 0x5C, 0xBD, 0xB7, 0xAD, 0x6C, 0xBA, 0xC0,
0x20, 0x83, 0xB8, 0xED, 0xB6, 0xB3, 0xBF, 0x9A, 0x0C, 0xE2, 0xB6, 0x03, 0x9A, 0xD2, 0xB1, 0x74,
0x39, 0x47, 0xD5, 0xEA, 0xAF, 0x77, 0xD2, 0x9D, 0x15, 0x26, 0xDB, 0x04, 0x83, 0x16, 0xDC, 0x73,
0x12, 0x0B, 0x63, 0xE3, 0x84, 0x3B, 0x64, 0x94, 0x3E, 0x6A, 0x6D, 0x0D, 0xA8, 0x5A, 0x6A, 0x7A,
0x0B, 0xCF, 0x0E, 0xE4, 0x9D, 0xFF, 0x09, 0x93, 0x27, 0xAE, 0x00, 0x0A, 0xB1, 0x9E, 0x07, 0x7D,
0x44, 0x93, 0x0F, 0xF0, 0xD2, 0xA3, 0x08, 0x87, 0x68, 0xF2, 0x01, 0x1E, 0xFE, 0xC2, 0x06, 0x69,
0x5D, 0x57, 0x62, 0xF7, 0xCB, 0x67, 0x65, 0x80, 0x71, 0x36, 0x6C, 0x19, 0xE7, 0x06, 0x6B, 0x6E,
0x76, 0x1B, 0xD4, 0xFE, 0xE0, 0x2B, 0xD3, 0x89, 0x5A, 0x7A, 0xDA, 0x10, 0xCC, 0x4A, 0xDD, 0x67,
0x6F, 0xDF, 0xB9, 0xF9, 0xF9, 0xEF, 0xBE, 0x8E, 0x43, 0xBE, 0xB7, 0x17, 0xD5, 0x8E, 0xB0, 0x60,
0xE8, 0xA3, 0xD6, 0xD6, 0x7E, 0x93, 0xD1, 0xA1, 0xC4, 0xC2, 0xD8, 0x38, 0x52, 0xF2, 0xDF, 0x4F,
0xF1, 0x67, 0xBB, 0xD1, 0x67, 0x57, 0xBC, 0xA6, 0xDD, 0x06, 0xB5, 0x3F, 0x4B, 0x36, 0xB2, 0x48,
0xDA, 0x2B, 0x0D, 0xD8, 0x4C, 0x1B, 0x0A, 0xAF, 0xF6, 0x4A, 0x03, 0x36, 0x60, 0x7A, 0x04, 0x41,
0xC3, 0xEF, 0x60, 0xDF, 0x55, 0xDF, 0x67, 0xA8, 0xEF, 0x8E, 0x6E, 0x31, 0x79, 0xBE, 0x69, 0x46,
0x8C, 0xB3, 0x61, 0xCB, 0x1A, 0x83, 0x66, 0xBC, 0xA0, 0xD2, 0x6F, 0x25, 0x36, 0xE2, 0x68, 0x52,
0x95, 0x77, 0x0C, 0xCC, 0x03, 0x47, 0x0B, 0xBB, 0xB9, 0x16, 0x02, 0x22, 0x2F, 0x26, 0x05, 0x55,
0xBE, 0x3B, 0xBA, 0xC5, 0x28, 0x0B, 0xBD, 0xB2, 0x92, 0x5A, 0xB4, 0x2B, 0x04, 0x6A, 0xB3, 0x5C,
0xA7, 0xFF, 0xD7, 0xC2, 0x31, 0xCF, 0xD0, 0xB5, 0x8B, 0x9E, 0xD9, 0x2C, 0x1D, 0xAE, 0xDE, 0x5B,
0xB0, 0xC2, 0x64, 0x9B, 0x26, 0xF2, 0x63, 0xEC, 0x9C, 0xA3, 0x6A, 0x75, 0x0A, 0x93, 0x6D, 0x02,
0xA9, 0x06, 0x09, 0x9C, 0x3F, 0x36, 0x0E, 0xEB, 0x85, 0x67, 0x07, 0x72, 0x13, 0x57, 0x00, 0x05,
0x82, 0x4A, 0xBF, 0x95, 0x14, 0x7A, 0xB8, 0xE2, 0xAE, 0x2B, 0xB1, 0x7B, 0x38, 0x1B, 0xB6, 0x0C,
0x9B, 0x8E, 0xD2, 0x92, 0x0D, 0xBE, 0xD5, 0xE5, 0xB7, 0xEF, 0xDC, 0x7C, 0x21, 0xDF, 0xDB, 0x0B,
0xD4, 0xD2, 0xD3, 0x86, 0x42, 0xE2, 0xD4, 0xF1, 0xF8, 0xB3, 0xDD, 0x68, 0x6E, 0x83, 0xDA, 0x1F,
0xCD, 0x16, 0xBE, 0x81, 0x5B, 0x26, 0xB9, 0xF6, 0xE1, 0x77, 0xB0, 0x6F, 0x77, 0x47, 0xB7, 0x18,
0xE6, 0x5A, 0x08, 0x88, 0x70, 0x6A, 0x0F, 0xFF, 0xCA, 0x3B, 0x06, 0x66, 0x5C, 0x0B, 0x01, 0x11,
0xFF, 0x9E, 0x65, 0x8F, 0x69, 0xAE, 0x62, 0xF8, 0xD3, 0xFF, 0x6B, 0x61, 0x45, 0xCF, 0x6C, 0x16,
0x78, 0xE2, 0x0A, 0xA0, 0xEE, 0xD2, 0x0D, 0xD7, 0x54, 0x83, 0x04, 0x4E, 0xC2, 0xB3, 0x03, 0x39,
0x61, 0x26, 0x67, 0xA7, 0xF7, 0x16, 0x60, 0xD0, 0x4D, 0x47, 0x69, 0x49, 0xDB, 0x77, 0x6E, 0x3E,
0x4A, 0x6A, 0xD1, 0xAE, 0xDC, 0x5A, 0xD6, 0xD9, 0x66, 0x0B, 0xDF, 0x40, 0xF0, 0x3B, 0xD8, 0x37,
0x53, 0xAE, 0xBC, 0xA9, 0xC5, 0x9E, 0xBB, 0xDE, 0x7F, 0xCF, 0xB2, 0x47, 0xE9, 0xFF, 0xB5, 0x30,
0x1C, 0xF2, 0xBD, 0xBD, 0x8A, 0xC2, 0xBA, 0xCA, 0x30, 0x93, 0xB3, 0x53, 0xA6, 0xA3, 0xB4, 0x24,
0x05, 0x36, 0xD0, 0xBA, 0x93, 0x06, 0xD7, 0xCD, 0x29, 0x57, 0xDE, 0x54, 0xBF, 0x67, 0xD9, 0x23,
0x2E, 0x7A, 0x66, 0xB3, 0xB8, 0x4A, 0x61, 0xC4, 0x02, 0x1B, 0x68, 0x5D, 0x94, 0x2B, 0x6F, 0x2A,
0x37, 0xBE, 0x0B, 0xB4, 0xA1, 0x8E, 0x0C, 0xC3, 0x1B, 0xDF, 0x05, 0x5A, 0x8D, 0xEF, 0x02, 0x2D
};
int main()
{
char name[100] = { 0 };
std::cin >> name;
int len = strlen("plmm: 0xAAAAAAAA");
// 没用！！！！
//char str[100] = { 0 };
//for (size_t i = 0; i < 6; i++)
//{
// char tmp = arr1[i] & arr2[i];
// name[i] = tmp;
// name[i] &= arr1[i];
// name[i] ^= arr2[i];
// name[i] += i;
// str[i] = name[i];
//}
const char* str1 = "4339744";
unsigned int eax = 0xFFFFFFFF;
for (int i = 0; i < 6; i++)
{
unsigned char edx = str1[i];
edx ^= eax;
eax >>= 8;
eax ^= *(unsigned int*)(hexData +edx*4);
}
eax ^= 0xffffffff;
char check_code[100] = { 0 };
sprintf(check_code,"plmm: 0x%08X",eax);
std::cout << check_code;
}
效果：
总结
应该是代码写错了，按理说应该是用Name生成一个数组，然后用生成的这个数组计算crc，程序员写成了用生成数组的地址计算crc，一下子变成硬编码了