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# frozen_string_literal: true
module ActiveModel
module SecurePassword
extend ActiveSupport::Concern
# BCrypt hash function can handle maximum 72 bytes, and if we pass
# password of length more than 72 bytes it ignores extra characters.
# Hence need to put a restriction on password length.
MAX_PASSWORD_LENGTH_ALLOWED = 72
class << self
attr_accessor :min_cost # :nodoc:
end
self.min_cost = false
module ClassMethods
# Adds methods to set and authenticate against a BCrypt password.
# This mechanism requires you to have a +XXX_digest+ attribute.
# Where +XXX+ is the attribute name of your desired password.
#
# The following validations are added automatically:
# * Password must be present on creation
# * Password length should be less than or equal to 72 bytes
# * Confirmation of password (using a +XXX_confirmation+ attribute)
#
# If confirmation validation is not needed, simply leave out the
# value for +XXX_confirmation+ (i.e. don't provide a form field for
# it). When this attribute has a +nil+ value, the validation will not be
# triggered.
#
# For further customizability, it is possible to suppress the default
# validations by passing <tt>validations: false</tt> as an argument.
#
# Add bcrypt (~> 3.1.7) to Gemfile to use #has_secure_password:
#
# gem 'bcrypt', '~> 3.1.7'
#
# Example using Active Record (which automatically includes ActiveModel::SecurePassword):
#
# # Schema: User(name:string, password_digest:string, recovery_password_digest:string)
# class User < ActiveRecord::Base
# has_secure_password
# has_secure_password :recovery_password, validations: false
# 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.recovery_password = "42password"
# user.recovery_password_digest # => "$2a$04$iOfhwahFymCs5weB3BNH/uXkTG65HR.qpW.bNhEjFP3ftli3o5DQC"
# user.save # => true
# user.authenticate('notright') # => false
# user.authenticate('mUc3m00RsqyRe') # => user
# user.authenticate_recovery_password('42password') # => user
# User.find_by(name: 'david').try(:authenticate, 'notright') # => false
# User.find_by(name: 'david').try(:authenticate, 'mUc3m00RsqyRe') # => user
def has_secure_password(attribute = :password, validations: true)
# Load bcrypt gem only when has_secure_password is used.
# This is to avoid ActiveModel (and by extension the entire framework)
# being dependent on a binary library.
begin
require "bcrypt"
rescue LoadError
$stderr.puts "You don't have bcrypt installed in your application. Please add it to your Gemfile and run bundle install"
raise
end
attr_reader attribute
define_method("#{attribute}=") do |unencrypted_password|
if unencrypted_password.nil?
self.send("#{attribute}_digest=", nil)
elsif !unencrypted_password.empty?
instance_variable_set("@#{attribute}", unencrypted_password)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine.cost
self.send("#{attribute}_digest=", BCrypt::Password.create(unencrypted_password, cost: cost))
end
end
define_method("#{attribute}_confirmation=") do |unencrypted_password|
instance_variable_set("@#{attribute}_confirmation", unencrypted_password)
end
# Returns +self+ if the password is correct, otherwise +false+.
#
# class User < ActiveRecord::Base
# has_secure_password validations: false
# end
#
# user = User.new(name: 'david', password: 'mUc3m00RsqyRe')
# user.save
# user.authenticate_password('notright') # => false
# user.authenticate_password('mUc3m00RsqyRe') # => user
define_method("authenticate_#{attribute}") do |unencrypted_password|
attribute_digest = send("#{attribute}_digest")
BCrypt::Password.new(attribute_digest).is_password?(unencrypted_password) && self
end
alias_method :authenticate, :authenticate_password if attribute == :password
if validations
include ActiveModel::Validations
# This ensures the model has a password by checking whether the password_digest
# is present, so that this works with both new and existing records. However,
# when there is an error, the message is added to the password attribute instead
# so that the error message will make sense to the end-user.
validate do |record|
record.errors.add(attribute, :blank) unless record.send("#{attribute}_digest").present?
end
validates_length_of attribute, maximum: ActiveModel::SecurePassword::MAX_PASSWORD_LENGTH_ALLOWED
validates_confirmation_of attribute, allow_blank: true
end
end
end
end
end