class Net::IMAP::SASL::Authenticators

Registry for SASL authenticators

Registered authenticators must respond to #new or #call (e.g. a class or a proc), receiving any credentials and options and returning an authenticator instance. The returned object represents a single authentication exchange and must not be reused for multiple authentication attempts.

An authenticator instance object must respond to #process, receiving the server’s challenge and returning the client’s response. Optionally, it may also respond to #initial_response? and #done?. When #initial_response? returns true, #process may be called the first time with nil. When #done? returns false, the exchange is incomplete and an exception should be raised if the exchange terminates prematurely.

See the source for PlainAuthenticator, XOAuth2Authenticator, and ScramSHA1Authenticator for examples.

Public Class Methods

new(use_defaults: true, use_deprecated: true) click to toggle source

Create a new Authenticators registry.

This class is usually not instantiated directly. Use SASL.authenticators to reuse the default global registry.

When use_defaults is false, the registry will start empty. When use_deprecated is false, deprecated authenticators will not be included with the defaults.

# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 32
def initialize(use_defaults: true, use_deprecated: true)
  @authenticators = {}
  return unless use_defaults
  add_authenticator "Anonymous"
  add_authenticator "External"
  add_authenticator "OAuthBearer"
  add_authenticator "Plain"
  add_authenticator "Scram-SHA-1"
  add_authenticator "Scram-SHA-256"
  add_authenticator "XOAuth2"
  return unless use_deprecated
  add_authenticator "Login"      # deprecated
  add_authenticator "Cram-MD5"   # deprecated
  add_authenticator "Digest-MD5" # deprecated

Public Instance Methods

add_authenticator(mechanism) click to toggle source
add_authenticator(mechanism, authenticator_class)
add_authenticator(mechanism, authenticator_proc)

Registers an authenticator for authenticator to use. mechanism is the name of the SASL mechanism implemented by authenticator_class (for instance, "PLAIN").

If mechanism refers to an existing authenticator, the old authenticator will be replaced.

When only a single argument is given, the authenticator class will be lazily loaded from Net::IMAP::SASL::#{name}Authenticator (case is preserved and non-alphanumeric characters are removed..

# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 67
def add_authenticator(name, authenticator = nil)
  key =, ?-)
  authenticator ||= begin
    class_name = "#{name.gsub(/[^a-zA-Z0-9]/, "")}Authenticator".to_sym
    auth_class = nil
    ->(*creds, **props, &block) {
      auth_class ||= Net::IMAP::SASL.const_get(class_name)*creds, **props, &block)
  @authenticators[key] = authenticator
authenticator(mechanism, ...) → auth_session click to toggle source

Builds an authenticator instance using the authenticator registered to mechanism. The returned object represents a single authentication exchange and must not be reused for multiple authentication attempts.

All arguments (except mechanism) are forwarded to the registered authenticator’s #new or #call method. Each authenticator must document its own arguments.


This method is intended for internal use by connection protocol code only. Protocol client users should see refer to their client’s documentation, e.g. Net::IMAP#authenticate.

# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 107
def authenticator(mechanism, ...)
  key =, ?-)
  auth = @authenticators.fetch(key) do
    raise ArgumentError, 'unknown auth type - "%s"' % key
  auth.respond_to?(:new) ? :
Also aliased as: new
mechanism?(name) click to toggle source
# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 86
def mechanism?(name)
  key =, ?-)
names() click to toggle source

Returns the names of all registered SASL mechanisms.

# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 49
def names; @authenticators.keys end
new(mechanism, ...)
Alias for: authenticator
remove_authenticator(name) click to toggle source

Removes the authenticator registered for name

# File net-imap-0.4.9/lib/net/imap/sasl/authenticators.rb, line 81
def remove_authenticator(name)
  key =, ?-)