Methods
A
H
Included Modules
Class Public methods
attributes_protected_by_default()

Source: show | on GitHub 

    # File activemodel/lib/active_model/secure_password.rb, line 48
48:           def self.attributes_protected_by_default
49:             super + ['password_digest']
50:           end
Instance Public methods
has_secure_password()

Adds methods to set and authenticate against a BCrypt password. This mechanism requires you to have a password_digest attribute.

Validations for presence of password, confirmation of password (using a “password_confirmation“ attribute) are automatically added. You can add more validations by hand if need be.

You need to add bcrypt-ruby (~> 3.0.0) to Gemfile to use has_secure_password: 

  gem 'bcrypt-ruby', '~> 3.0.0'

Example using Active Record (which automatically includes ActiveModel::SecurePassword): 

  # Schema: User(name:string, password_digest:string)
  class User < ActiveRecord::Base
    has_secure_password
  end

  user = User.new(:name => "david", :password => "", :password_confirmation => "nomatch")
  user.save                                                      # => false, password required
  user.password = "mUc3m00RsqyRe"
  user.save                                                      # => false, confirmation doesn't match
  user.password_confirmation = "mUc3m00RsqyRe"
  user.save                                                      # => true
  user.authenticate("notright")                                  # => false
  user.authenticate("mUc3m00RsqyRe")                             # => user
  User.find_by_name("david").try(:authenticate, "notright")      # => nil
  User.find_by_name("david").try(:authenticate, "mUc3m00RsqyRe") # => user

Source: show | on GitHub 

    # File activemodel/lib/active_model/secure_password.rb, line 34
34:       def has_secure_password
35:         # Load bcrypt-ruby only when has_secure_password is used.
36:         # This is to avoid ActiveModel (and by extension the entire framework) being dependent on a binary library.
37:         gem 'bcrypt-ruby', '~> 3.0.0'
38:         require 'bcrypt'
39: 
40:         attr_reader :password
41: 
42:         validates_confirmation_of :password
43:         validates_presence_of     :password_digest
44: 
45:         include InstanceMethodsOnActivation
46: 
47:         if respond_to?(:attributes_protected_by_default)
48:           def self.attributes_protected_by_default
49:             super + ['password_digest']
50:           end
51:         end
52:       end