Rating:

# multidimensional (140 solves, 442 points)

## Description:
It's time to break through portals and get multidimensional! Can you cross through all 3 (or 4?) dimensions?

[Multidimensional.java](Multidimensional.java)

## Solution:
This challenge takes our input and does a bunch of manipulation and checks if it equals hey_since_when_was_time_a_dimension?. So all we have to do is reverse the functions and apply them to the checked string to get the flag. A lot of it was just copying the function and changing a couple things to make it do the opposite of the orginal file.

**Script:**
java
public class Solve {
private static char[][] arr = new char[6][6];
public static void main(String[] args) {
int[][] t = {{8, 65, -18, -21, -15, 55},
{8, 48, 57, 63, -13, 5},
{16, -5, -26, 54, -7, -2},
{48, 49, 65, 57, 2, 10},
{9, -2, -1, -9, -11, -10},
{56, 53, 18, 42, -28, 5}};
String connolly = "hey_since_when_was_time_a_dimension?";
System.out.println("Start: ");
for (int x = 0; x < 6; x++) {
for (int y = 0; y < 6; y++) {
arr[x][y] = connolly.charAt(6 * x + y);
}
}
printArr(arr);
System.out.println("\nreversing time");
//reverse time
for (int j = 0; j < arr[0].length; j++) {
for (int i = 0; i < arr.length; i++) {
arr[i][j] -= t[j][i];
}
}
printArr(arr);
System.out.println("\nreversing space");
revSpace(35);
printArr(arr);
//reversing plane
System.out.println("\nreversing plane");
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
arr[i][j] -= i + 6 - j;
}
}
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
char temp = arr[i][j];
arr[i][j] = arr[5 - j][i];
arr[5 - j][i] = arr[5 - i][5 - j];
arr[5 - i][5 - j] = arr[j][5 -i];
arr[j][5 -i] = temp;

}
}
printArr(arr);

//reverse line
System.out.println("\nreversing line");
char[][] newArr = new char[arr.length][arr[0].length];
for (int i = 0; i < arr.length; i++) {
for (int j = 0; j < arr[0].length; j++) {
int p = i - 1, q = j - 1, f = 0;
boolean row = i % 2 == 0;
boolean col = j % 2 == 0;
if (row) {
p = i + 1;
f++;
} else
f--;
if (col) {
q = j + 1;
f++;
} else
f--;
newArr[i][j] = (char) (arr[p][q] - f);
}
}
arr = newArr;
printArr(arr);
String ans = "";
for (int i = 0; i < 36; i++) {
ans += arr[i % 6][i / 6];
}
System.out.println(ans);
}
public static void revSpace(int n) {
arr[(35 - n) / 6][(35 - n) % 6] += (n / 6) + (n % 6);
if (n != 0) {
n--;
revSpace(n);
}
}
public static void printArr(char[][] array) {
for (int x = 0; x < 6; x++) {
for (int y = 0; y < 6; y++) {
System.out.print(array[x][y] + " ");
}
System.out.println("");
}
}

}

## Flag:
flag{th3_g4t3w4y_b3t233n_d1m3n510n5}

Original writeup (https://github.com/BASHing-thru-challenges/HSCTF-2021-Writeups/tree/main/rev/multidimensional).