How would you do the following using Python and Python Flask:

Password Login form - This Python form allows a user to login to a simple web application with a username and password. A file can be used to store the username and password for validated users for this activity. No additional Web application functionality is needed after successful login other than a Greeting of your choice and the ability to update the password in a form.

b. Password update Form - This Python form allows a user to update a user's password after they have successfully logged in.

c. Authentication functions - These Python functions that will check the following NIST SP 800-63B criteria are met upon login or upon password update: SHALL be at least 8 characters in length

SHOULD be no more than 64 characters in length