Change cookie key to cookie key suffix

README.md

@@ -310,8 +310,8 @@ You can configure the MfaSession cookie by creating an initializer:
 # The cookie normally expires in 24 hours, you can change this to 1 month
 GoogleAuthenticatorRails.time_until_expiration = 1.month
 
-# You can override the cookie's key, by default this is <class>_mfa_credentials
-GoogleAuthenticatorRails.cookie_key = 'mfa_credentials'
+# You can override the suffix of the cookie's key, by default this is mfa_credentials
+GoogleAuthenticatorRails.cookie_key_suffix = 'mfa_credentials'
 
 # Rails offers a few more cookie options, by default only :httponly is turned on, you can change it to HTTPS only:
 GoogleAuthenticatorRails.cookie_options = { :httponly => true, :secure => true, :domain => :all }

lib/google-authenticator-rails.rb

@@ -29,8 +29,8 @@ module GoogleAuthenticatorRails
   # How long a Session::Persistence cookie should last.
   @@time_until_expiration = 24.hours
 
-  # Name of a Session::Persistence cookie
-  @@cookie_key = nil
+  # Last part of a Session::Persistence cookie's key
+  @@cookie_key_suffix = nil
 
   # Additional configuration passed to a Session::Persistence cookie.
   @@cookie_options = { :httponly => true }
@@ -59,12 +59,12 @@ def self.time_until_expiration=(time_until_expiration)
     @@time_until_expiration = time_until_expiration
   end
 
-  def self.cookie_key
-    @@cookie_key
+  def self.cookie_key_suffix
+    @@cookie_key_suffix
   end
 
-  def self.cookie_key=(key)
-    @@cookie_key = key
+  def self.cookie_key_suffix=(suffix)
+    @@cookie_key_suffix = suffix
   end
 
   def self.cookie_options

lib/google-authenticator-rails/session/persistence.rb

@@ -67,7 +67,8 @@ def create_cookie(token, user_id)
       end
 
       def cookie_key
-        GoogleAuthenticatorRails.cookie_key || "#{klass.to_s.downcase}_mfa_credentials"
+        suffix = "#{GoogleAuthenticatorRails.cookie_key_suffix}" || 'mfa_credentials'
+        "#{klass.to_s.downcase}_#{suffix}"
       end
     end