Add tracking of certain important user actions. These events include:
* Logins
* Logouts
* Failed login attempts
* Account creations
* Account deletions
* Password reset requests
* Password changes
* Email address changes
This is similar to the mod actions log, except for account activity
related to a single user.
The information tracked includes the user, the event type (login,
logout, etc), the timestamp, the user's IP address, IP geolocation
information, the user's browser user agent, and the user's session ID
from their session cookie. This information is visible to mods only.
This is done with three models. The UserEvent model tracks the event
type (login, logout, password change, etc) and the user. The UserEvent
is tied to a UserSession, which contains the user's IP address and
browser metadata. Finally, the IpGeolocation model contains the
geolocation information for IPs, including the city, country, ISP, and
whether the IP is a proxy.
This tracking will be used for a few purposes:
* Letting users view their account history, to detect things like logins
from unrecognized IPs, failed logins attempts, password changes, etc.
* Rate limiting failed login attempts.
* Detecting sockpuppet accounts using their login history.
* Detecting unauthorized account sharing.
* Make authentication methods into User instance methods instead of
class methods.
* Fix API key authentication to use a secure string comparison. Fixes a
hypothetical (unlikely to be exploitable) timing attack.
* Move login logic from SessionCreator to SessionLoader.
Remove the "Remember" checkbox from the login page. Make session cookies
permanent instead. Phase out legacy `user_name` and `password_hash` cookies.
Previously a user's session cookies would be cleared whenever they
closed their browser window, which would log them out of the site. To
work around this, when the "Remember" box was checked on the login page
(which it was by default), the user's name and password hash (!) would
be stored in separate permanent cookies, which would be used to
automatically log the user back in when their session cookies were
cleared. We can avoid all of this just by making the session cookies
themselves permanent.
* Allow both xml and json authentication in sessions controller.
* Raise an exception if a login attempt fails so that a) we return a
proper error for json/xml requests and b) failed login attempts get
reported to NewRelic (for monitoring abuse).
