EMAIL COOKIE AUTHENTICATION
---------------------------

NickServ can use email authentication for various things, offloading
some human support.  If email cookies are enabled, each handle can
have an associated email address (if they're not enabled, current
email addresses are preserved, but not displayed or used.)  If email
cookies are disabled, the rest of this section does not apply.

Cookies (10-character case-sensitive alphanumeric strings; they are
base64-encoded random numbers) are used for the following things:

- Handle activation.  When a new handle is registered, its password is
  set to an unusable string.  A cookie is sent to that email address,
  and can later be used to auth and change the password (as for
  forgotten password changes, below).

- Changing email addresses.  When an authed user requests that their
  email address be changed, half of the cookie is sent to each; both
  halves must be presented to complete the change.

- Allowauth (in addition to the normal staff allowauth command).  A
  cookie is sent to the handle's address, and if the user responds
  with that cookie, they are allowauth'ed.

- Changing forgotten passwords.  A user may request a cookie be sent
  to their email address; this will allow them to auth and change
  their password.

The following limitations apply:

- Only one cookie will be issued per handle at a time.  The current
  cookie must be used or time out before another one is issued.

- Cookies time out after a configurable amount of time (defaults to 24
  hours).

- Only one un-activated handle is allowed per email address.

The following commands are provided (overriding non-cookie commands of
the same name, if there is overlap):

- REGISTER <handle> <password> [<email_addr>]
  - Registers the handle.  If email address provided, emails user with
    a cookie that allows them to activate their handle.  Otherwise,
    sets password to what they request.
- SET EMAIL <new_email>
  - Mails cookie to new email address (if one already exists, mails
    half to new, half to old).
- AUTHCOOKIE <handle>
  - Emails cookie for authentication.
- RESETPASS <handle> <newpass>
  - Begins password reset process for a handle.
- COOKIE [<handle>] <cookie>
  - If handle's cookie type is REGSTER, activates a handle that was
    registered using REGISTER, setting handle's password to what is
    specified.
  - If handle's cookie type is EMAIL_CHANGE, changes email address.
  - If handle's cookie type is PASSWORD_CHANGE, changes password.
  - If handle's cookie type is ALLOWAUTH, allows user to auth if
    password matches.