module ActiveModel::SecurePassword::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.

Additionally, a XXX_challenge attribute is created. When set to a value other than nil, it will validate against the currently persisted password. This validation relies on dirty tracking, as provided by ActiveModel::Dirty; if dirty tracking methods are not defined, this validation will fail.

All of the above validations can be omitted by passing validations: false as an argument. This allows complete customizability of validation behavior.

Finally, a password reset token that’s valid for 15 minutes after issue is automatically configured when reset_token is set to true (which it is by default) and the object reponds to generates_token_for (which Active Records do).

To use has_secure_password, add bcrypt (~> 3.1.7) to your Gemfile:

gem "bcrypt", "~> 3.1.7"

Examples

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 = "vr00m"
user.save                                                      # => false, confirmation doesn't match
user.password_confirmation = "vr00m"
user.save                                                      # => true

user.authenticate("notright")                                  # => false
user.authenticate("vr00m")                                     # => user
User.find_by(name: "david")&.authenticate("notright")          # => false
User.find_by(name: "david")&.authenticate("vr00m")             # => user

user.recovery_password = "42password"
user.recovery_password_digest                                  # => "$2a$04$iOfhwahFymCs5weB3BNH/uXkTG65HR.qpW.bNhEjFP3ftli3o5DQC"
user.save                                                      # => true

user.authenticate_recovery_password("42password")              # => user

user.update(password: "pwn3d", password_challenge: "")         # => false, challenge doesn't authenticate
user.update(password: "nohack4u", password_challenge: "vr00m") # => true

user.authenticate("vr00m")                                     # => false, old password
user.authenticate("nohack4u")                                  # => user

Conditionally requiring a password

class Account
  include ActiveModel::SecurePassword

  attr_accessor :is_guest, :password_digest

  has_secure_password

  def errors
    super.tap { |errors| errors.delete(:password, :blank) if is_guest }
  end
end

account = Account.new
account.valid? # => false, password required

account.is_guest = true
account.valid? # => true

Using the password reset token

user = User.create!(name: "david", password: "123", password_confirmation: "123")
token = user.password_reset_token
User.find_by_password_reset_token(token) # returns user

# 16 minutes later...
User.find_by_password_reset_token(token) # returns nil

# raises ActiveSupport::MessageVerifier::InvalidSignature since the token is expired
User.find_by_password_reset_token!(token)