#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ give_shell();
int /*<<< orphan*/ puts(char *);
int /*<<< orphan*/ scanf(char *, char *);
scalar_t__ strcmp(char *, char *);
void vuln() {
  char password[16];
  puts("What is the password: ");
  scanf("%s", password);
  if (strcmp(password, "31337h4x") == 0) {
    puts("Correct password!");
    give_shell();
  } else {
    puts("Incorrect password!");
  }
}


x86 assembly (clang, -O0):
<vuln>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
lea    0xeb1(%rip),%rdi
call   1030 <puts@plt>
lea    -0x10(%rbp),%rsi
lea    0xeb8(%rip),%rdi
call   1060 <scanf@plt>
lea    -0x10(%rbp),%rdi
lea    0xeab(%rip),%rsi
call   1040 <strcmp@plt>
cmp    $0x0,%rax
jne    1196 <vuln+0x56>
lea    0xe9e(%rip),%rdi
call   1030 <puts@plt>
mov    $0x0,%al
call   1050 <give_shell@plt>
jmp    11a2 <vuln+0x62>
lea    0xe98(%rip),%rdi
call   1030 <puts@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<vuln>:
push   %rbx
sub    $0x10,%rsp
lea    0xeb4(%rip),%rdi
call   1030 <puts@plt>
lea    0xebf(%rip),%rdi
mov    %rsp,%rbx
mov    %rbx,%rsi
call   1060 <scanf@plt>
lea    0xeb0(%rip),%rsi
mov    %rbx,%rdi
call   1040 <strcmp@plt>
test   %rax,%rax
je     1185 <vuln+0x45>
lea    0xeb7(%rip),%rdi
call   1030 <puts@plt>
jmp    1198 <vuln+0x58>
lea    0xe97(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
call   1050 <give_shell@plt>
add    $0x10,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [23 x i8] c"What is the password: \00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [9 x i8] c"31337h4x\00"
@.str.3 = [18 x i8] c"Correct password!\00"
@.str.4 = [20 x i8] c"Incorrect password!\00"
define void @vuln() {
%1 = alloca [16 x i8]
%2 = call i32 @puts(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0))
%3 = getelementptr inbounds [16 x i8], [16 x i8]* %1, i64 0, i64 0
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %3)
%5 = getelementptr inbounds [16 x i8], [16 x i8]* %1, i64 0, i64 0
%6 = call i64 @strcmp(i8* %5, i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0))
%7 = icmp eq i64 %6, 0
br i1 %7, label %8, label %11
8: ; preds = %0
%9 = call i32 @puts(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.3, i64 0, i64 0))
%10 = call i32 (...) @give_shell()
br label %13
11: ; preds = %0
%12 = call i32 @puts(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.4, i64 0, i64 0))
br label %13
13: ; preds = %11, %8
ret void
}

LLVM IR (-O2):
@.str = [23 x i8] c"What is the password: \00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [9 x i8] c"31337h4x\00"
@.str.3 = [18 x i8] c"Correct password!\00"
@.str.4 = [20 x i8] c"Incorrect password!\00"
define void @vuln() {
%1 = alloca [16 x i8]
%2 = getelementptr inbounds [16 x i8], [16 x i8]* %1, i64 0, i64 0
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %2)
%5 = call i64 @strcmp(i8* %2, i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0))
%6 = icmp eq i64 %5, 0
br i1 %6, label %7, label %10
7: ; preds = %0
%8 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([18 x i8], [18 x i8]* @.str.3, i64 0, i64 0))
%9 = call i32 (...) @give_shell()
br label %12
10: ; preds = %0
%11 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 x i8]* @.str.4, i64 0, i64 0))
br label %12
12: ; preds = %10, %7
ret void
}