Question

Write a Python (3) program to simulate** a buffer overflow (this is a new script, not part of the intranet assignment), then implement input validation to prevent it. There are two parts to this assignment:

1) The program should display a welcome message and prompt the user for a username. Create a simulated buffer overflow condition by allowing a user to input more data than the size of the allocated memory (causing the program to crash).

2) Implement input validation to mitigate the simulated overflow vulnerability. Check that the username entered has a minimum length of 8 characters and a maximum of 25 characters. If the user enters a username length outside those limits, return an error message and prompt the user to re-enter the username.

Please submit two python files (one for part 1, and another for part 2) associated with your assignment, as well as instructions for testing your programs (README.txt).

if it need a input.txt, please help me to create one,

Answer 1

Part 1: Following is the program which raises the exception.

print('Welcome User')
username = input('Enter the name: ')
if len(username) > 25:
    raise Exception('The character length should be less than 25')

Following is the snippet of the output

Part 2: For this part, we need to raise the exception as well as handle the same.

Following is the code for the same.

print('Welcome User')
done_input = False
while not done_input:
    username = input('Enter the username: ')
    try:
        if len(username) < 8 or len(username) > 25:
            raise Exception()
        else:
            done_input = True
    except:
        print('Username length should be between 8 and 25')
print('Welcome ' + str(username))

Friend, If you have any doubts in understanding do let me know in the comment section. I will be happy to help you further.
Thanks