Methods
Instance Public methods
authenticate_by(attributes)
Given a set of attributes, finds a record using the non-password attributes, and then authenticates that record using the password attributes. Returns the record if authentication succeeds; otherwise, returns nil.
Regardless of whether a record is found, authenticate_by will cryptographically digest the given password attributes. This behavior helps mitigate timing-based enumeration attacks, wherein an attacker can determine if a passworded record exists even without knowing the password.
Raises an ArgumentError if the set of attributes doesn’t contain at least one password and one non-password attribute.
Examples
class User < ActiveRecord::Base
has_secure_password
end
User.create(name: "John Doe", email: "jdoe@example.com", password: "abc123")
User.authenticate_by(email: "jdoe@example.com", password: "abc123").name # => "John Doe" (in 373.4ms)
User.authenticate_by(email: "jdoe@example.com", password: "wrong") # => nil (in 373.9ms)
User.authenticate_by(email: "wrong@example.com", password: "abc123") # => nil (in 373.6ms)
User.authenticate_by(email: "jdoe@example.com", password: nil) # => nil (no queries executed)
User.authenticate_by(email: "jdoe@example.com", password: "") # => nil (no queries executed)
User.authenticate_by(email: "jdoe@example.com") # => ArgumentError
User.authenticate_by(password: "abc123") # => ArgumentError
📝 Source code
# File activerecord/lib/active_record/secure_password.rb, line 41
def authenticate_by(attributes)
passwords, identifiers = attributes.to_h.partition do |name, value|
!has_attribute?(name) && has_attribute?("#{name}_digest")
end.map(&:to_h)
raise ArgumentError, "One or more password arguments are required" if passwords.empty?
raise ArgumentError, "One or more finder arguments are required" if identifiers.empty?
return if passwords.any? { |name, value| value.nil? || value.empty? }
if record = find_by(identifiers)
record if passwords.count { |name, value| record.public_send(:"authenticate_#{name}", value) } == passwords.size
else
new(passwords)
nil
end
end