Asm-3 PicoCTF Challenge

Challenge

Test.S :

asm3:
	<+0>:	push   ebp
	<+1>:	mov    ebp,esp
	<+3>:	xor    eax,eax
	<+5>:	mov    ah,BYTE PTR [ebp+0x9]
	<+8>:	shl    ax,0x10
	<+12>:	sub    al,BYTE PTR [ebp+0xe]
	<+15>:	add    ah,BYTE PTR [ebp+0xf]
	<+18>:	xor    ax,WORD PTR [ebp+0x12]
	<+22>:	nop
	<+23>:	pop    ebp
	<+24>:	ret    

Cleaning The GAS Up

.intel_syntax noprefix
.global asm3

/* Needed To Clean This Up */

asm3:
	push   ebp
	mov    ebp,esp
	xor    eax,eax
	mov    ah,BYTE PTR [ebp+0x9]
	shl    ax,0x10
	sub    al,BYTE PTR [ebp+0xe]
	add    ah,BYTE PTR [ebp+0xf]
	xor    ax,WORD PTR [ebp+0x12]
	nop
	pop    ebp
	ret    

C program to retrieve the flag!

#include <stdio.h>

int asm3(int, int, int);

int main(int argc, char* argv[]) {
  printf("0x%x\n", asm3(0xd2c26416,0xe6cf51f0,0xe54409d5));
  return 0;
}

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