flame.c

//
// This file was generated by the Retargetable Decompiler
// Website: https://retdec.com
// Copyright (c) 2016 Retargetable Decompiler <info@retdec.com>
//

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// --------------------- Global Variables ---------------------

char * g1; // 0x1007899c

// ------------------------ Functions -------------------------

// Address range: 0x1000078c - 0x100009bf
int main(int argc, char ** argv) {
    int32_t v1; // bp-432
    v1 = &v1;
    int32_t v2;
    memcpy((char *)&v2, (char *)&g1, 140);
    puts("*************************************");
    puts("*                                   *");
    puts("*   HITCON CTF 2016 Flag Verifier   *");
    puts("*                                   *");
    puts("*************************************");
    printf("Check your flag before submission: ");
    int32_t str;
    scanf("%s", &str);
    if (strlen((char *)&str) != 35) {
        // 0x10000964
        puts("Your flag is incorrect :(");
        // branch -> 0x10000974
        // 0x10000974
        return 0;
    }
    // 0x1000084c
    srandom(0x1e61);
    int32_t v3;
    int32_t v4 = &v3; // 0x10000874_0
    int32_t v5 = 0;
    // branch -> 0x10000860
    int32_t v6;
    while (true) {
        uint32_t v7 = rand() % 0x1000; // 0x10000868
        int32_t * v8 = (int32_t *)(v4 - 384 + 4 * v5); // 0x10000880_0
        *v8 = v7;
        unsigned char v9 = *(char *)(v5 + (int32_t)&str); // 0x100008ac
        *v8 = (int32_t)v9 ^ v7;
        if (v5 > 33) {
            v6 = 0;
            // break -> 0x100008f4
            break;
        }
        v5++;
        // continue -> 0x10000860
    }
    while (true) {
        int32_t v10 = 4 * v6 + v4; // 0x10000900
        if (*(int32_t *)(v10 - 244) == *(int32_t *)(v10 - 384)) {
            // 0x10000938
            if (v6 > 33) {
                // break -> 0x10000944
                break;
            }
            v6++;
            // continue -> 0x100008f4
            continue;
        }
    }
    // 0x10000944
    puts("Good job!! now you can submit your flag :)");
    // branch -> 0x10000974
    // 0x10000974
    return 0;
}

// --------------- Statically Linked Functions ----------------

// void * memcpy(void * restrict dest, const void * restrict src, size_t n);
// int printf(const char * restrict format, ...);
// int puts(const char * s);
// int rand(void);
// int scanf(const char * restrict format, ...);
// void srandom(unsigned int seed);
// size_t strlen(const char * s);

// --------------------- Meta-Information ---------------------

// Detected compiler/packer: gcc (5.4.0)
// Detected functions: 1
// Decompiler release: v2.2.1 (2016-09-07)
// Decompilation date: 2016-10-08 12:26:09