roaming in a small space
Baby RE
Show us your basic skills! (P.S. There are 4 ways to solve this, are you willing to try them all?)
kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ file baby
baby: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=25adc53b89f781335a27bf1b81f5c4cb74581022, for GNU/Linux 3.2.0, not stripped
kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ ./baby
Insert key:
HTB{B4BY_R3V_TH4TS_EZ}
Try again later.
kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ strings baby
HTB{B4BYH
R3V_TH4H TS_Ef []A\A]A^A
Dont run strings
on this challenge, that is not the way!!!!
Insert key:
abcde122313
Try again later.
kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ ./baby
Insert key:
abcde122313
HTB{B4BY_R3V_TH4TS_EZ}
ghidra
undefined8 main(void)
{
int iVar1;
undefined8 local_48;
undefined8 local_40;
undefined4 local_38;
undefined2 local_34;
char local_28 [24];
char *local_10;
local_10 = "Dont run `strings` on this challenge, that is not the way!!!!";
puts("Insert key: ");
fgets(local_28,0x14,stdin);
iVar1 = strcmp(local_28,"abcde122313\n");
if (iVar1 == 0) {
local_48 = 0x594234427b425448;
local_40 = 0x3448545f5633525f;
local_38 = 0x455f5354;
local_34 = 0x7d5a;
puts((char *)&local_48);
}
else {
puts("Try again later.");
}
return 0;
}
kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ unhex 594234427b425448
YB4B{BTHkali@kali:~/0.htb/challenges/Reversing/Baby_RE$ unhex 3448545f5633525f
4HT_V3R_kali@kali:~/0.htb/challenges/Reversing/Baby_RE$ unhex 455f5354
E_STkali@kali:~/0.htb/challenges/Reversing/Baby_RE$ unhex 7d5a
}Zkali@kali:~/0.htb/challenges/Reversing/Baby_RE$
}E_ST4HT_V3R_YB4B{BTH
gdb ida radare2 r2:
ida
mov rax, 594234427B425448h
mov rdx, 3448545F5633525Fh
mov qword ptr [rbp+var_40], rax
mov [rbp+var_38], rdx
mov [rbp+var_30], 455F5354h
mov [rbp+var_2C], 7D5Ah
lea rax, [rbp+var_40]
mov rdi, rax ; s
call _puts
jmp short loc_11E6
gdb
0x00000000000011a3 <+78>: movabs rax,0x594234427b425448
0x00000000000011ad <+88>: movabs rdx,0x3448545f5633525f
0x00000000000011b7 <+98>: mov QWORD PTR [rbp-0x40],rax
0x00000000000011bb <+102>: mov QWORD PTR [rbp-0x38],rdx
0x00000000000011bf <+106>: mov DWORD PTR [rbp-0x30],0x455f5354
0x00000000000011c6 <+113>: mov WORD PTR [rbp-0x2c],0x7d5a
0x00000000000011cc <+119>: lea rax,[rbp-0x40]
0x00000000000011d0 <+123>: mov rdi,rax
0x00000000000011d3 <+126>: call 0x1030 <puts@plt>
0x00000000000011d8 <+131>: jmp 0x11e6 <main+145>
0x00000000000011da <+133>: lea rdi,[rip+0xe7f] # 0x2060
0x00000000000011e1 <+140>: call 0x1030 <puts@plt>
0x00000000000011e6 <+145>: mov eax,0x0
r2/cutter
0x000011a3 48b84854427b. movabs rax, 0x594234427b425448 ; 'HTB{B4BY'
│ │ 0x000011ad 48ba5f523356. movabs rdx, 0x3448545f5633525f ; '_R3V_TH4'
│ │ 0x000011b7 488945c0 mov qword [s], rax
│ │ 0x000011bb 488955c8 mov qword [var_38h], rdx
│ │ 0x000011bf c745d054535f. mov dword [var_30h], 0x455f5354 ; 'TS_E'
│ │ 0x000011c6 66c745d45a7d mov word [var_2ch], 0x7d5a ; 'Z}'
│ │ 0x000011cc 488d45c0 lea rax, [s]
│ │ 0x000011d0 4889c7 mov rdi, rax ; const char *s
│ │ 0x000011d3 e858feffff call sym.imp.puts ; int puts(const char *s)
│ ┌──< 0x000011d8 eb0c jmp 0x11e6