Extract some logic to a service

app/controllers/casino/auth_tokens_controller.rb

@@ -1,30 +1,13 @@
 class CASino::AuthTokensController < CASino::ApplicationController
-  before_action :validate_auth_token_signature, :validate_auth_token_ticket
-
   def login
-    raise "#{auth_token_data[:username]} logged in successfully"
+    user = validator_service.extract_user
+    redirect_to_login unless user
   end
 
   private
-  def validate_auth_token_signature
-    digest = OpenSSL::Digest::SHA256.new
-    Dir.glob(Rails.root.join('config/auth_token_signers/*.pem')) do |file|
-      key = OpenSSL::PKey::RSA.new File.read(file)
-      if key.verify(digest, auth_token_signature, auth_token)
-        logger.info "Successfully validated auth token signature with #{file}"
-        return true
-      end
-    end
-    logger.info 'Auth token signature is not valid'
-    redirect_to_login
-  end
-
-  def validate_auth_token_ticket
-    unless auth_token_ticket_valid?(auth_token_data[:ticket])
-      redirect_to_login
-    end
+  def validator_service
+    @validator_service ||= CASino::AuthTokenValidatorService.new(auth_token, auth_token_signature)
   end
-
   def redirect_to_login
     redirect_to login_path(service: params[:service])
   end
@@ -38,19 +21,10 @@ def auth_token
   end
 
   def base64_decode(data)
-    return '' if data.nil?
     begin
       Base64.strict_decode64(data)
     rescue
       ''
     end
   end
-
-  def auth_token_data
-    JSON.parse(auth_token).symbolize_keys
-  end
-
-  def auth_token_ticket_valid?(auth_token_ticket)
-    CASino::AuthTokenTicket.consume(auth_token_ticket)
-  end
 end

app/services/casino/auth_token_validator_service.rb

@@ -0,0 +1,41 @@
+class CASino::AuthTokenValidatorService
+  AUTH_TOKEN_SIGNERS_GLOB = Rails.root.join('config/auth_token_signers/*.pem').freeze
+
+  attr_reader :token, :signature
+
+  def initialize(token, signature)
+    @token = token
+    @signature = signature
+  end
+
+  def extract_user
+    return false unless signature_valid?
+    return false unless ticket_valid?
+    raise "#{token_data[:username]} logged in successfully"
+  end
+
+  def token_data
+    begin
+      JSON.parse(token).symbolize_keys
+    rescue
+      {}
+    end
+  end
+
+  private
+  def signature_valid?
+    digest = OpenSSL::Digest::SHA256.new
+    Dir.glob(AUTH_TOKEN_SIGNERS_GLOB) do |file|
+      key = OpenSSL::PKey::RSA.new(File.read(file))
+      if key.verify(digest, signature, token)
+        Rails.logger.info("Successfully validated auth token signature with #{file}")
+        return true
+      end
+    end
+    false
+  end
+
+  def ticket_valid?
+    CASino::AuthTokenTicket.consume(token_data[:ticket])
+  end
+end