新手破解练习Crackme160之064 - execution

1. 暴力破解, OD关键字搜索定位到关键跳0040DB9C , nop掉 进入成功分支, 保存, 搞定~

2. 正常破解, 向上找到方法入口0040D8F0, 开始单步调试, 算法分析:
   1). 输入转大写
   2). 每一位ascii值 - 0x40
   3). 再 * 0x82
   4). 再 + edi低4位
   5) 再 + 16次 0x50
   以上每步操作完都是低4位操作并判断是否变负数了, 得及时转换回正数, 代码如下, keygen.c

#include <stdio.h>
#include "string.h"

int main() {
	char user[20] = {0};
	printf("请输入用户名: ");
	scanf("%s", user);
	int len = strlen(user);
	int eax = 1, edi = 0;
	for(int i=0; i<len; i++){
		if((user[i] >= 'a') && (user[i] <= 'z')) { user[i] -= 0x20; } //转大写 
		eax = (user[i] - 0x40) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax * 0x82) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + (edi & 0xFFFF)) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF; //下面加16次0x50 
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		eax = (eax + 0x50) & 0xFFFF;
		if(eax < 0) { eax *= -1; }
		edi = eax;
	}
	
 	printf("系列号为: %d\n\n按任意键继续~", edi);
 	getchar();getchar();
    return 0;
}

这是160个软件part1
这是160个软件part2

1~160每个破解过程,在吾爱破解论坛都有高手破解过了,也有整理好现成的, 我这边主要就是自己动手操作的过程,与他们的不太一样
附上高手们的连接: 点击前往查看
使用的工具连接(工具有点多有点大,可以先下OD,其它的后面慢慢下) 点击前往下载

新人入门教程"玩玩破解，写给新人看" 点击前往查看
我就是从这里开始的,对我这样的小白感觉超级友好~

下面是我的OD的界面布局,我觉得这4个是最常用的界面,其它的我基本上没用到~