• Add built-in Argon2 support for has_secure_password.

  has_secure_password now supports Argon2 as a built-in algorithm:

  class User < ActiveRecord::Base
    has_secure_password algorithm: :argon2
  end

  To use Argon2, add gem "argon2", "~> 2.3" to your Gemfile.

  Argon2 has no password length limit, unlike BCrypt's 72-byte restriction.

  Justin Bull, Guillermo Iguaran

• Add ActiveModel::SecurePassword.register_algorithm to register new algorithms for has_secure_password by symbol:

  ActiveModel::SecurePassword.register_algorithm can be used to register new algorithms:

  ActiveModel::SecurePassword.register_algorithm :custom_password, CustomPassword

  class User < ActiveRecord::Base
    has_secure_password algorithm: :custom_password
  end

  BCrypt is pre-registered as :bcrypt in the algorithms registry.

  Justin Bull, Guillermo Iguaran

• has_secure_password can support different password hashing algorithms (if defined) using the :algorithm option:

  class CustomPassword
    def hash_password(unencrypted_password)
      CustomHashingLibrary.create(unencrypted_password)
    end
  
    def verify_password(password, digest)
      CustomHashingLibrary.verify(password, digest)
    end
  
    def password_salt(digest)
      CustomHashingLibrary.salt(digest)
    end
  
    def validate(record, attribute)
      # ...
    end
  
    def algorithm_name
      :custom
    end
  end

  class User < ActiveRecord::Base
    has_secure_password algorithm: CustomPassword.new
  end

  Justin Bull, Lucas Mazza

• Allow passing method name or proc to allow_nil and allow_blank

  class EnrollmentForm
    include ActiveModel::Validations
  
    attr_accessor :course
  
    validates :course,
              inclusion: { in: :open_courses },
              allow_nil: :saving_progress?
  end

  Richard Lynch

• Add error type support arguments to ActiveModel::Errors#messages_for and ActiveModel::Errors#full_messages_for

  person = Person.create()
  person.errors.full_messages_for(:name, :invalid)
  # => ["Name is invalid"]
  
  person.errors.messages_for(:name, :invalid)
  # => ["is invalid"]

  Eugene Bezludny

• Make ActiveModel::Serializers::JSON#from_json compatible with #assign_attributes

  Sean Doyle

Please check [8-1-stable]) for previous changes.