Hack with Rainbow method: getting the KeyError

I’m trying to find some passwords using the Rainbow method. I have a CSV file containing people’s names and their hashed passwords using SHA-256. I have to retrieve the original passwords which are four-digit numbers [1000-9999].

The CSV file:

danial,99b057c8e3461b97f8d6c461338cf664bc84706b9cc2812daaebf210ea1b9974
elham,85432a9890aa5071733459b423ab2aff9f085f56ddfdb26c8fae0c2a04dce84c

My code:

import hashlib
import csv
    
def hash_password_hack(passwords, new_passwords):
    with open (r'passwords.csv','r', encoding='utf-8') as f:
        reader=csv.reader(f)
        dict1={}
        for row in reader:
            dict1[row[1]]=row[0]
        dict2={}
        for i in range (1000,10000):
            hashed_password=hashlib.sha256(str(i).encode('utf-8'))
            dict2[hashed_password]=i
        for key in dict1:
            with open (r'new_passwords.csv', 'w', newline='') as f1:
                writer=csv.writer(f1)
                password=dict2[key]
                name=dict1[key]
                writer.writerow([name,password])

When I run the code, following error appears:

KeyError: '99b057c8e3461b97f8d6c461338cf664bc84706b9cc2812daaebf210ea1b9974'

As I know, this error appears when the dictionary I try to call doesn’t have that specific key. Since I’ve hashed every number between 1000 and 9999, dict2 has to contain the above key. Why do I get this error, and how can I solve it?

Answer

hashlib.sha256(str(i).encode('utf-8')) returns a HASH object, not the hex hash, so you are keying by object. Instead, you want to use the hexdigest() method to get the hex hash e.g. hashed_password = hashlib.sha256(str(i).encode('utf-8')).hexdigest().