Masking Input on Windows

Masking password input with feedback

If an application asks a user for sensitive information from the command line, ideally one should be able to do this:

username = input("Username")
password = input("Password", masked=True)  # error

However, that's not supported. Python offers the getpass module which is like this:

import getpass
password = getpass.getpass("Password")
Password

While this effectively hides the password, I prefer to give feedback on how many characters have been entered (indicated with '*')

Created: 2020-06-20

Updated: 2021-04-29

import msvcrt

def win_getpass(prompt='Password: ', stream=None, placeholder="*"):
    """Prompt for password with echo off, using Windows getch()."""
    for c in prompt:
        msvcrt.putwch(c)
    pw = ""
    while 1:
        c = msvcrt.getwch()
        if c == '\r' or c == '\n':
            break
        if c == '\003':
            raise KeyboardInterrupt
        if c == '\b':
            # User enters the backspace key
            pw = pw[:-1]
            # Move one character left
            msvcrt.putwch('\b')
            # Overwrite placeholder with whitespace
            msvcrt.putwch(' ')
            # Move one character left, again
            msvcrt.putwch('\b')
        else:
            pw = pw + c
            msvcrt.putwch(placeholder)
    msvcrt.putwch('\r')
    msvcrt.putwch('\n')
    return pw

My Notes

Masking Input on Windows