How to have password echoed as asterisks

I’m trying make a login window where a user is prompted to enter their Username and Password, although when the password is entered I am looking for asterisks to be printed, like common password entry (i.e. – Sekr3t is echo’d as: * * * * * *).

Here’s the code I have so far, and I can’t figure out why it doesn’t echo asterisks:

import msvcrt
import sys

def login(prompt = '> '):
   write = sys.stdout.write
   
   for x in prompt:
       msvcrt.putch(x)
   passw = ""
   
   while 1:
       x = msvcrt.getch()
       if x == 'r' or x == 'n':
           break
       if x == 'b':
           # position of my error
           passw = passw[:-1]
       else:
           write('*')
           passw = passw + x
   msvcrt.putch('r')
   msvcrt.putch('n')
   return passw

Any help would be appreciated.

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

You should be able to erase an asterisk by writing the characters x08 x08. The x08 will move the cursor back one position, the space will overwrite the asterisk, then the last x08 will move the cursor back again, putting it in the correct position to write the next *.

I don’t know off the top of my head how to determine when a backspace is typed, but you can do that easily: just add something like print repr(x) after you’ve called x = msvcrt.getch(), then start your program and hit backspace.

Method 2

I think this way is very simple and effective

import sys
import msvcrt

passwor = ''
while True:
    x = msvcrt.getch()
    if x == 'r':
        break
    sys.stdout.write('*')
    passwor +=x

print 'n'+passwor

Method 3

I did all this years ago… in Shell…

For ideas on improving it further…
https://antofthy.gitlab.io/info/crypto/passwd_askpass_stars.txt

Final script with many bells and whistles and still evolving
https://antofthy.gitlab.io/software/#askpass_stars

Note that you really should not include this directly in your program, but make it a password helper, so that many programs can use it. EG: set a program using an environment variable (like TTY_ASKPASS) or other configuration.

See https://stackoverflow.com/a/67327327/701532

By doing this you are not limiting the user to what YOU provide, but allowing the password to be sourced from other places. “ssh” and even “sudo” also does this.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0