1 files changed, 13 insertions, 7 deletions
diff --git a/activesupport/lib/active_support/message_verifier.rb b/activesupport/lib/active_support/message_verifier.rb
index 854029bf83..8419e858c6 100644
--- a/activesupport/lib/active_support/message_verifier.rb
+++ b/activesupport/lib/active_support/message_verifier.rb
@@ -1,6 +1,6 @@
-require 'base64'
-require 'active_support/core_ext/object/blank'
-require 'active_support/security_utils'
+require "base64"
+require "active_support/core_ext/object/blank"
+require "active_support/security_utils"
 
 module ActiveSupport
   # +MessageVerifier+ makes it easy to generate and verify messages which are
@@ -24,13 +24,19 @@ module ActiveSupport
   # hash upon initialization:
   #
   #   @verifier = ActiveSupport::MessageVerifier.new('s3Krit', serializer: YAML)
+  #
+  # +MessageVerifier+ creates HMAC signatures using SHA1 hash algorithm by default.
+  # If you want to use a different hash algorithm, you can change it by providing
+  # `:digest` key as an option while initializing the verifier:
+  #
+  #   @verifier = ActiveSupport::MessageVerifier.new('s3Krit', digest: 'SHA256')
   class MessageVerifier
     class InvalidSignature < StandardError; end
 
     def initialize(secret, options = {})
-      raise ArgumentError, 'Secret should not be nil.' unless secret
+      raise ArgumentError, "Secret should not be nil." unless secret
       @secret = secret
-      @digest = options[:digest] || 'SHA1'
+      @digest = options[:digest] || "SHA1"
       @serializer = options[:serializer] || Marshal
     end
 
@@ -77,7 +83,7 @@ module ActiveSupport
           data = signed_message.split("--".freeze)[0]
           @serializer.load(decode(data))
         rescue ArgumentError => argument_error
-          return if argument_error.message =~ %r{invalid base64}
+          return if argument_error.message.include?("invalid base64")
           raise
         end
       end
@@ -121,7 +127,7 @@ module ActiveSupport
       end
 
       def generate_digest(data)
-        require 'openssl' unless defined?(OpenSSL)
+        require "openssl" unless defined?(OpenSSL)
         OpenSSL::HMAC.hexdigest(OpenSSL::Digest.const_get(@digest).new, @secret, data)
       end
   end