How to Limit Logins in Python Code

Python programs allow users to log in using log-in credentials. In order to avoid hacking, you should instill some sort of log-in limit to avoid brute force attacks, which are characterized by hackers entering multiple passwords until they find the correct one. In this case, set aside a log-in logfile to track the amount of user log-in attempts throughout a certain time period.

Instructions

1. Create a log script:

   >>>def logIn(name, passwd):
   . . . /*checks database for user name and information*/
   . . .

2. Read from the log script, which contains the information for log-in attempts. This should occur prior to any queries to the database:

   >>>def logIn(name, passwd):
   . . . f = open('/var/log/login.txt')
   . . . contents = f.read()

3. Check log-in attempts by searching for the index of the name and reading the line. This file assumes that the log file will follow a format in which each line represents a user and is formatted as "username = login_attempts." For example, if Bob tried to log in twice, his line would read "Bob = 2."

   . . . contents = f.read()
   . . . index = contents.find(name)
   . . . while content[index] != ' ':
   . . . index += 1
   . . . index += 2
   . . . attempts = contents[index]

4. If a user makes more log-in attempts than allowed, deny access. If not, add one to attempts and store in file. In this example, the limit of log-in attempts is four:

   . . . if attempts == '4':
   . . . print 'Too many attempts, aborting...'
   . . . return
   . . . else:
   . . . /*query database for login credentials*/

5. Add a log-in attempt to the list:

   . . . x = int(content[index])
   . . . x += 1
   . . . content[index] = str(x)

References

• Python: Input and Output