discourse/lib/auth/authenticator.rb

# this class is used by the user and omniauth controllers, it controls how
#  an authentication system interacts with our database and middleware

class Auth::Authenticator
  def name
    raise NotImplementedError
  end

  def enabled?
    raise NotImplementedError
  end

  # run once the user has completed authentication on the third party system. Should return an instance of Auth::Result.
  # If the user has requested to connect an existing account then `existing_account` will be set
  def after_authenticate(auth_options, existing_account: nil)
    raise NotImplementedError
  end

  # can be used to hook in after the authentication process
  #  to ensure records exist for the provider in the db
  #  this MUST be implemented for authenticators that do not
  #  trust email
  def after_create_account(user, auth)
    # not required
  end

  # hook used for registering omniauth middleware,
  #  without this we can not authenticate
  def register_middleware(omniauth)
    raise NotImplementedError
  end

  # return a string describing the connected account
  #  for a given user (typically email address). Used to list
  #  connected accounts under the user's preferences. Empty string
  #  indicates not connected
  def description_for_user(user)
    ""
  end

  # can authorisation for this provider be revoked?
  def can_revoke?
    false
  end

  # can exising discourse users connect this provider to their accounts
  def can_connect_existing_user?
    false
  end

  # optionally implement the ability for users to revoke
  #  their link with this authenticator.
  # should ideally contact the third party to fully revoke
  #  permissions. If this fails, return :remote_failed.
  # skip remote if skip_remote == true
  def revoke(user, skip_remote: false)
    raise NotImplementedError
  end
end