Rating: 0

-compiled binary no header or tables

used r2 to decompile and debug.
```

[0x01002059]> pdf
/ (fcn) entry0 68
| entry0 ();
| 0x01002004 58 pop eax
| 0x01002005 3c02 cmp al, 2 ; 2 CHECKS IF THERE IS A ARGUMENT
| ,=< 0x01002007 740b je 0x1002014
| | ; CODE XREF from entry0 (0x100205d)
| .--> 0x01002009 b37f mov bl, 0x7f ; 127
| :| 0x0100200b 31c0 xor eax, eax 0
| :| 0x0100200d 40 inc eax 1 == exit
| :| 0x0100200e cd80 int 0x80 syscall
| :| 0x01002010 0200 add al, byte [eax]
| :| 0x01002012 0300 add eax, dword [eax]
| :| ; CODE XREF from entry0 (0x1002007)
| :`-> 0x01002014 b420 mov ah, 0x20 ; 32 or space
| :,=< 0x01002016 eb16 jmp 0x100202e
..
| :| ; CODE XREF from entry0 (0x1002016)
| :`-> 0x0100202e 31c9 xor ecx, ecx ;
| : 0x01002030 bb00200001 mov ebx, map.home_m42d_Desktop_CTFs_akbar_Native_native.rwx ; 0x1002000
| : 0x01002035 5e pop esi ; (path)
| : 0x01002036 5e pop esi ; (arguments)
| : 0x01002037 eb01 jmp 0x100203a ; a NOP is a NOP
| : 0x0100203a 204b0a and byte [ebx + 0xa], cl
| : ; CODE XREF from entry0 (0x100205b)
| :.-> 0x0100203d 56 push esi ; arg pointer back on stack
| :: 0x0100203e 53 push ebx ; push pointer to beginning of file on stack
| :: 0x0100203f 01ce add esi, ecx ;
| :: 0x01002041 01cb add ebx, ecx ; add counter2 to file pointer
| :: 0x01002043 31d2 xor edx, edx ;
| :: 0x01002045 30c0 xor al, al ;
| :: ; CODE XREF from entry0 (0x100204f)
| .---> 0x01002047 0203 add al, byte [ebx] ; add byte that filepointer points to to al
| ::: 0x01002049 00e3 add bl, ah ; move file pointer 32 bytes
| ::: 0x0100204b 42 inc edx ; counter2++
| ::: 0x0100204c 83fa04 cmp edx, 4 ;
| `===< 0x0100204f 75f6 jne 0x1002047 ; so this loop happens 4 times
| :: 0x01002051 5b pop ebx ;
| :: 0x01002052 3206 xor al, byte [esi] ; xor the value of that calculated with the byte counter
| :: 0x01002054 08430a or byte [ebx + 0xa], al ; OR het resultaat met wat filepointer + 10
| :: 0x01002057 5e pop esi ; reset file pointer to start of file
| :: 0x01002058 41 inc ecx ; counter++
| :: ;-- eip:
| :: 0x01002059 b 38e1 cmp cl, ah ; counter == 0x20
| :`=< 0x0100205b 75e0 jne 0x100203d ;
\ `==< 0x0100205d ebaa jmp 0x1002009 ;

```

python script to extract flag.

```
f = open("native", "r")
b = f.read()
m = ""
for p in range(0,32):
m += chr(int(hex(ord(b[p])+ord(b[p+0x20])+ord(b[p+0x40])+ord(b[p+0x60]))[-2:],16))
print m
```

FLAG{tiny_f1f_analysis_is__real}