
Password policy
==========================================
This module provides a way to specify a certain level of password
complexity (aka. "password hardening") for user passwords on a
system by defining a password policy.

A password policy can be defined with a set of constraints which
must be met before a user password change will be accepted. Each
constraint has a parameter allowing for the minimum number of valid
conditions which must be met before the constraint is satisfied.

Example: an uppercase constraint (with a parameter of 2) and a
digit constraint (with a parameter of 4) means that a user password
must have at least 2 uppercase letters and at least 4 digits for it
to be accepted.

Current constraints include:

  * Digit constraint
  * Letter constraint
  * Letter/Digit constraint (Alphanumeric)
  * Length constraint
  * Uppercase constraint
  * Lowercase constraint
  * Punctuation constraint
  * Character types constraint (allows the administrator to set the minimum
    number of character types required, but without actually dictating which
    ones must be used.  Example - Windows requires any 3 (user's choice) of
    uppercase, lowercase, numbers, or punctuation.
  * History constraint (checks hashed password against a
    collection of users previous hashed passwords looking for
    recent duplicates)
  * Username constraint

The module also implements configurable password expiration features:

  * When a password is not changed for a certain amount of time the user will
    be forced to change their password on next login.
  * Optionally, the user will also be blocked upon password expiration.
  * Expiration of passwords can begin after expiration time from enabling
    the policy or immediately all users with passwords older than expiration
    time will be blocked (retroactive behavior).
  * Expiration notifications (warnings) are mailed to the users several times
    (configurable) before the password expires.
  * Warning e-mail message's subject and body are configurable.

Limitations
==========================================
Password policies only apply to passwords set via user forms in the web
interface. Passwords changed by other means (Drush, web services, etc.) will
not be subject to password policy constraints. Please see the following issue
if you would like to contribute to removing this limitation:

	https://www.drupal.org/node/2451159

Security note
==========================================
Enforcing tough policy is only good from a technical standpoint. You are 
likely to end up with a situation where the users write down their super
secure and super impossible to remember passwords. Help texts on how can
you memorize such things (like shifting a word one row up the keyboard
and so on). You should have separate company policy that deters users from
writing passwords on a Post-it on the backside of their keyboard.

Consider a company policy to use strong password generator tools like
http://supergenpass.com/ or 1Password on MacOS.

Credits
==========================================
Drupal 4.7 version was written by David Ayre <drupal at ayre dot ca>
Refactored and maintained by Miglius Alaburda <miglius at gmail dot com>
Sponsored by Bryght, SPAWAR, McDean
