实验吧 defcamp r200.bak 反汇编

链接:http://www.shiyanbar.com/ctf/2020

下面是反汇编的源码:

#include <stdio.h>
#include<stdlib.h>

typedef struct list
{
    int num;
    char ch;
    char no_use[3];
    struct list *next;
} list;

list *global = NULL;

int exe(char *str)
{
    int i;          
    int j;          
    int temp;     
    list *p_list; 
    int src[6];

    int dst[] = {5, 2, 7, 2, 5, 6}; 

    for (i = 0; i <= 5; ++i)
    {
        p_list = global;
        temp = 0;
        while (p_list != NULL)
        {
            if (p_list->ch == str[i])
            {
                temp = p_list->num;
                break;
            }
            p_list = p_list->next;
        }
        src[i] = temp;
    }
    for (j = 0; j <= 5; ++j)
    {
        if (src[j] != dst[j])
        {
            return 1;
        }
    }
    return 0;
}

int main()
{
    char buf[16];
    int i;
    for (i = 1; i <= 10; ++i)
    {
        list *temp = (list *)malloc(sizeof(list));
        temp->num = i;
        temp->ch = i + 109;
        temp->next = global;
        global = temp;
    }

    printf("Enter the password: ");
    if (!fgets(buf, 7, stdin))
    {
        return 0;
    }

    if (exe(buf))
    {
        puts("Incorrect password!");
    }
    else
    {
        puts("Nice!");
    }
}

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