1 files changed, 40 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/secure_token.rb b/activerecord/lib/active_record/secure_token.rb
new file mode 100644
index 0000000000..bcdb33901b
--- /dev/null
+++ b/activerecord/lib/active_record/secure_token.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module SecureToken
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      # Example using #has_secure_token
+      #
+      #   # Schema: User(token:string, auth_token:string)
+      #   class User < ActiveRecord::Base
+      #     has_secure_token
+      #     has_secure_token :auth_token
+      #   end
+      #
+      #   user = User.new
+      #   user.save
+      #   user.token # => "pX27zsMN2ViQKta1bGfLmVJE"
+      #   user.auth_token # => "77TMHrHJFvFDwodq8w7Ev2m7"
+      #   user.regenerate_token # => true
+      #   user.regenerate_auth_token # => true
+      #
+      # <tt>SecureRandom::base58</tt> is used to generate the 24-character unique token, so collisions are highly unlikely.
+      #
+      # Note that it's still possible to generate a race condition in the database in the same way that
+      # {validates_uniqueness_of}[rdoc-ref:Validations::ClassMethods#validates_uniqueness_of] can.
+      # You're encouraged to add a unique index in the database to deal with this even more unlikely scenario.
+      def has_secure_token(attribute = :token)
+        # Load securerandom only when has_secure_token is used.
+        require "active_support/core_ext/securerandom"
+        define_method("regenerate_#{attribute}") { update! attribute => self.class.generate_unique_secure_token }
+        before_create { send("#{attribute}=", self.class.generate_unique_secure_token) unless send("#{attribute}?") }
+      end
+
+      def generate_unique_secure_token
+        SecureRandom.base58(24)
+      end
+    end
+  end
+end