Timing Attack for 4 digits password

Timing Attack for 4 digits password

"""
The function check_password(password) is used by a safe with 4-digits passwords, and is 
susceptible to timing attacks. More specifically, it takes it around 0.1 seconds to check 
one digit – so brute-forcing all the possible combinations will take around 1,500 hours. 
Can you implement a way to crack its password in less than a minute?
"""

import time
import sys # ignore

sys.path.insert(0,'.') # ignore
from pswd import real_password

def check_password(password): # Don't change it
    if len(password) != len(real_password):
        return False
    for x, y in zip(password, real_password):
        time.sleep(0.1) # Simulates the wait time of the safe's mechanism
        if int(x) != int(y):
            return False
    return True

def crack_password():
    password = ""
    inp = ""
    # loop for every element in the password, in this case there are 4 elements in the password
    # before running this cracking code, we need to find how many elements does the password composed of
    for turn in range(4):
        print("- - -" + str(turn) + "- - -" )
        # loop for finding the correct char
        for char in "0123456789":
            inp = password + char
            inp += "0"*(4-len(inp))
            print(inp)

            t1 = int(round(time.time() * 1000))
            if (not check_password(inp)):
                # this will work for every char for each turn of the password untill the last turn of the loop inside the check_password() function
                t2 = int(round(time.time() * 1000))
                elapsedTime = round((t2 - t1)/100) * 100 # in order to get round milliseconds elapsed

                if( elapsedTime > 100*(turn+1) ):
                    print(str(turn+1) + " th digit: " + char + ">>>" +str(elapsedTime))
                    password += char
                    break
            else:
                # This else work when the last correct char is found. Therefore, last char will be added here and break the for loop
                password += char
                print("All password: " + password)
                break

        inp = ""
    return password

# this function is not used, I used times (*) functionaly istead of this, for example: "0"*(4-len(inp))
def printCustomNumberOfChar(char, count):
    var = ""
    for e in range(count):
        var += char
    return var