Added digest_class configuration option

lib/active_support/cache/dalli_store.rb

@@ -345,7 +345,7 @@ def namespaced_key(key, options)
         namespace = options[:namespace] if options
         prefix = namespace.is_a?(Proc) ? namespace.call : namespace
         key = "#{prefix}:#{key}" if prefix
-        key = "#{key[0, 213]}:md5:#{::Digest::MD5.hexdigest(key)}" if key && key.size > 250
+        key = "#{key[0, 213]}:md5:#{@options[:digest_class].hexdigest(key)}" if key && key.size > 250
         key
       end
       alias :normalize_key :namespaced_key

lib/dalli/client.rb

@@ -29,8 +29,10 @@ class Client
     # - :serializer - defaults to Marshal
     # - :compressor - defaults to zlib
     # - :cache_nils - defaults to false, if true Dalli will not treat cached nil values as 'not found' for #fetch operations.
+    # - :digest_class - defaults to Digest::MD5, allows you to pass in an object that responds to the hexdigest method, useful for injecting a FIPS compliant hash object.
     #
     def initialize(servers=nil, options={})
+      options[:digest_class] = ::Digest::MD5 unless options[:digest_class]
       @servers = normalize_servers(servers || ENV["MEMCACHE_SERVERS"] || '127.0.0.1:11211')
       @options = normalize_options(options)
       @ring = nil
@@ -351,7 +353,9 @@ def ring
             server_options[:password] = uri.password
             s = "#{uri.host}:#{uri.port}"
           end
-          Dalli::Server.new(s, @options.merge(server_options))
+          options = @options.dup.merge(server_options)
+          options.delete(:digest_class)
+          Dalli::Server.new(s, options)
         end, @options
       )
     end
@@ -379,7 +383,7 @@ def validate_key(key)
       key = key_with_namespace(key)
       if key.length > 250
         max_length_before_namespace = 212 - (namespace || '').size
-        key = "#{key[0, max_length_before_namespace]}:md5:#{Digest::MD5.hexdigest(key)}"
+        key = "#{key[0, max_length_before_namespace]}:md5:#{@options[:digest_class].hexdigest(key)}"
       end
       return key
     end
@@ -407,6 +411,9 @@ def normalize_options(opts)
       rescue NoMethodError
         raise ArgumentError, "cannot convert :expires_in => #{opts[:expires_in].inspect} to an integer"
       end
+      unless opts[:digest_class].respond_to? :hexdigest
+        raise ArgumentError, "The digest_class object must respond to the hexdigest method"
+      end
       opts
     end
 

test/test_active_support.rb

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 require 'connection_pool'
+require 'openssl'
 
 class MockUser
   def cache_key
@@ -50,6 +51,17 @@ def self.it_with_and_without_local_cache(message, &block)
       with_cache :expires_in => 5.minutes, :frob => 'baz' do
         assert_equal 'baz', @dalli.options[:frob]
       end
+
+      with_cache :expires_in => 5.minutes, :digest_class => OpenSSL::Digest::SHA1 do
+        assert_equal OpenSSL::Digest::SHA1, @dalli.options[:digest_class]
+      end
+    end
+
+    it 'uses valid digest_class option' do
+      with_cache :expires_in => 5.minutes, :digest_class => OpenSSL::Digest::SHA1 do
+        dvalue = @dalli.fetch('a_key') { 123 }
+        assert_equal 123, dvalue
+      end
     end
 
     it_with_and_without_local_cache 'allow mute and silence' do

test/test_dalli.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 require_relative 'helper'
+require 'openssl'
 
 describe 'Dalli' do
   describe 'options parsing' do
@@ -33,6 +34,12 @@
       assert_equal "wunderschoen", dc.send(:namespace)
       dc.close
     end
+
+    it 'raises error with invalid digest_class' do
+      assert_raises ArgumentError do
+        Dalli::Client.new('foo', {:expires_in => 10, :digest_class => Object })
+      end
+    end
   end
 
   describe 'key validation' do
@@ -529,7 +536,7 @@
         dc.close
         dc = nil
 
-        dc = Dalli::Client.new("localhost:#{port}")
+        dc = Dalli::Client.new("localhost:#{port}", :digest_class => ::OpenSSL::Digest::SHA1)
 
         assert op_addset_succeeds(dc.set('456', 'xyz', 0, :raw => true))