Rev-AmateursCTF2023-Volcano
- DIE
1 | |
sub.c
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103#include <stdio.h>
#include <stdbool.h>
int sub_1209(int x) {
int v3;
v3 = 0;
while(x){
++v3;
x /= 10;
}
return v3;
}
int sub_124D(int x) {
int v3 = 0;
while (x){
v3 += x % 10;
x /= 10;
}
return v3;
}
int sub_1430(int a, int b, int c) {
int v5;
int v6 = 1;
v5 = a % c;
while (b){
if ((b&1)!=0)
v6 = v5 * v6%c;
b >>= 1;
v5 = v5 * v5 % c;
}
return v6;
}
bool isbear(unsigned int bear){
if ((bear & 1) != 0)
return false;
if ((bear % 3) !=2)
return false;
if ((bear % 5) != 1)
return false;
if ((bear % 7) == 3)
return bear % 0x6D == 55;
return false;
}
bool isvol(unsigned int v){
unsigned int result;
result = 0;
while (v){
result += v & 1;
v >>= 1;
}
return result > 0x10 && result <= 0x1A;
}
int main() {
int v9;
int v10 = 4919;
int volcano;
int bear;
printf("Finding numbers that satisfy the conditions...\n");
for (unsigned int bear = 0; bear < 1000000; bear++) {
if (isbear(bear)) {
for (unsigned int volcano = 0; volcano < 1000000; volcano++) {
if (isvol(volcano) &&
sub_1209(volcano) == sub_1209(bear) &&
sub_124D(volcano) == sub_124D(bear)) {
for (v9 = 3; v9 < 1000000; v9 += 2) {
if (v9 != 1 &&
sub_1430(v10, volcano, v9) == sub_1430(v10, bear, v9)) {
printf("Found a number that satisfies the conditions: %d\n", v9);
printf("bear: %u, volcano: %u\n", bear, volcano);
return 0;
}
}
}
}
}
}
return 0;
}
FLAG
1
amateursCTF{yep_th0se_l00k_th3_s4me_to_m3!_:clueless:}
Rev-AmateursCTF2023-Volcano
https://luoming1995125.github.io/2023/07/27/Rev-AmateursCTF2023-Volcano/