22018,

1/1101

해킹잘하고싶다

http://없음

lob 연습할 때 도움되는 자료 (직접 만들었음)

http://www.hackerschool.org/HS_Boards/zboard.php?id=Free_Board&no=37877 [복사]

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

#define MAX_LEN 256

// Convert input string like "\\x31\\xc0..." into actual byte array
int decode_shellcode(const char *input, unsigned char *output) {
    int len = strlen(input);
    int out_idx = 0;

    for (int i = 0; i < len;) {
        // Check for "\xNN" pattern
        if (input[i] == '\\' && input[i+1] == 'x' &&
            isxdigit(input[i+2]) && isxdigit(input[i+3])) {
            char hex[3] = { input[i+2], input[i+3], '\0' };
            output[out_idx++] = (unsigned char)strtol(hex, NULL, 16);
            i += 4;
        } else {
            return -1; // Invalid format
        }
    }
    return out_idx; // Number of bytes converted
}

int main(void)
{
    char your_answer[MAX_LEN];
    char *shellcode_25bytes = "\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e"
                               "\x89\xe3\x50\x53\x89\xe1\x31\xd2\xb0\x0b\xcd\x80";

    unsigned char decoded_input[MAX_LEN];

    while (1) {
        // Prompt user for shellcode input
        printf("Enter the shellcode('q' to exit) : ");
        fgets(your_answer, MAX_LEN, stdin);
        your_answer[strcspn(your_answer, "\n")] = '\0';  // Remove newline character

        // Exit if input is "q"
        if (strcmp(your_answer, "q") == 0) {
            exit(0);
        }

        // Decode input into raw bytes
        int decoded_len = decode_shellcode(your_answer, decoded_input);

        if (decoded_len < 0) {
            printf("Invalid format. Use \\xNN format.\n");
            continue;
        }

        // Compare decoded input with actual shellcode
        if (decoded_len == strlen(shellcode_25bytes) &&
            memcmp(decoded_input, shellcode_25bytes, decoded_len) == 0) {
            printf("correct!!!\n");
            break;
        } else {
            printf("fail...\n");
        }
    }

    return 0;
}

Hit : 1622 Date : 2025/05/07 06:30