The voices… I need them silenced. Use these runes to turn their screams into meaningless mumbles.

flag format: itu{$program_output}

What to do?

rewrite thingy in c run program get output paste in flag

how?

we get:

section .data
    str db "intheendiwastheonlyoneleftstandinginthefieldaloneandpowerlessbutasiassembledmylastwordsicarriedintothefiremylastpunchfilledwithsoul", 0
    newline db 10

section .text
    global main
    extern putchar

main:
    push    rbp
    mov     rbp, rsp
    mov     r12d, 3
    
loop_start:
    movzx   edi, BYTE [str + r12]
    test    edi, edi
    je      loop_end
    call    putchar
    add     r12d, 4
    jmp     loop_start
    
loop_end:
    mov     edi, 10
    call    putchar
    xor     eax, eax
    mov     rsp, rbp
    pop     rbp
    ret

So lets break it down.

String Setup The str variable holds a null-terminated string.

char str[] = "intheendiwastheonlyoneleftstandinginthefieldaloneandpowerlessbutasiassembledmylastwordsicarriedintothefiremylastpunchfilledwithsoul";

Start Index r12d is set to 3, so the program starts from the 4th character (ix from 0).

int i = 3;

Loop

  • movzx edi, BYTE [str + r12] Load character from str[r12].
  • test edi, edi + je If character is 0 (null terminator), exit loop.
  • call putchar Print the character.
  • add r12d, 4 Move 4 characters ahead.
  • jmp Repeat.
    for (int i = 3; str[i] != ''; i += 4) {
        putchar(str[i]);
    }

End After the loop, it prints a newline (10) and returns 0.

    putchar('\n');
    return 0;

All together:

int main() {
    char str[] = "intheendiwastheonlyoneleftstandinginthefieldaloneandpowerlessbutasiassembledmylastwordsicarriedintothefiremylastpunchfilledwithsoul";
    
    for (int i = 3; str[i] != ''; i += 4) {
        putchar(str[i]);
    }

    putchar('\n');
    return 0;
}