An Emacs minor mode to hide sensitive information in buffers (passwords) using overlays.

This is not a replacement for a real password manager. Emacs already provides an implementation of the Secret Service API (Gnome Keyring client): secrets.el

But there may be situation when you have to deal with passwords in plain text files. You can further increase security by using GPG: http://blog.bogosity.se/2011/01/12/managing-passwords-using-gnupg-git-and-emacs/

(require 'password-mode)
(add-hook 'text-mode-hook 'password-mode)

There is a prefix regexp used to find the text before the password:

(defcustom password-mode-password-prefix-regexs
  '("Password:\s+" "Passwort:\s+"))

There is also a regexp used to find the actual password:

(defcustom password-mode-password-regex
  "\\([[:graph:]]*\\)"

When you try to changes a password (hidden by the overlay) an Emacs password prompt is invoked to read the actual password.

Use (password-mode-copy-as-kill) to copy the next password to the kill-ring.