So, I've heard you're kinda new to reverse-engineering ?

Basically, in almost every challenge you'll be provided a binary hiding a secret.
Your goal is generally to break the secret checking function in order to recover the flag.
For this you'll need to understand the assembly code and write back the corresponding C code if you need to (or you can do it in real-time if you're not human).

To make it easier, i'll give you the flag checking function only and your task will be to recover which input returns 1.
I advise you to do some research about x86 ISA and x86 linux calling convention first.

Good luck !


0000000000001139 <check_secret>:
    1139:       55                      push   rbp
    113a:       48 89 e5                mov    rbp,rsp
    113d:       48 89 7d e8             mov    QWORD PTR [rbp-0x18],rdi
    1141:       48 8b 45 e8             mov    rax,QWORD PTR [rbp-0x18]
    1145:       48 89 45 f8             mov    QWORD PTR [rbp-0x8],rax
    1149:       48 8b 45 f8             mov    rax,QWORD PTR [rbp-0x8]
    114d:       8b 00                   mov    eax,DWORD PTR [rax]
    114f:       35 40 20 5b 7f          xor    eax,0x7f5b2040
    1154:       89 45 f0                mov    DWORD PTR [rbp-0x10],eax
    1157:       48 8b 45 f8             mov    rax,QWORD PTR [rbp-0x8]
    115b:       48 83 c0 04             add    rax,0x4
    115f:       8b 00                   mov    eax,DWORD PTR [rax]
    1161:       35 53 23 59 76          xor    eax,0x76592353
    1166:       89 45 f4                mov    DWORD PTR [rbp-0xc],eax
    1169:       81 7d f0 37 13 37 13    cmp    DWORD PTR [rbp-0x10],0x13371337
    1170:       75 10                   jne    1182 <check_secret+0x49>
    1172:       81 7d f4 37 13 37 13    cmp    DWORD PTR [rbp-0xc],0x13371337
    1179:       75 07                   jne    1182 <check_secret+0x49>
    117b:       b8 01 00 00 00          mov    eax,0x1
    1180:       eb 05                   jmp    1187 <check_secret+0x4e>
    1182:       b8 00 00 00 00          mov    eax,0x0
    1187:       5d                      pop    rbp
    1188:       c3                      ret