Fix Lint/DeprecatedOpenSSLConstant auto-correction of OpenSSL::Cipher to use lower case

CHANGELOG.md

@@ -9,6 +9,7 @@
 * [#8257](https://github.com/rubocop-hq/rubocop/issues/8257): Fix an error for `Style/BisectedAttrAccessor` when using `attr_reader` and `attr_writer` with splat arguments. ([@fatkodima][])
 * [#8239](https://github.com/rubocop-hq/rubocop/pull/8239): Don't load `.rubocop.yml` from personal folders to check for exclusions if given a custom configuration file. ([@deivid-rodriguez][])
 * [#8256](https://github.com/rubocop-hq/rubocop/issues/8256): Fix an error for `--auto-gen-config` when running a cop who do not support auto-correction. ([@koic][])
+* [#8262](https://github.com/rubocop-hq/rubocop/pull/8262): Fix `Lint/DeprecatedOpenSSLConstant` auto-correction of `OpenSSL::Cipher` to use lower case, as some Linux-based systems do not accept upper cased cipher names. ([@bdewater][])
 
 ## 0.87.0 (2020-07-06)
 

docs/modules/ROOT/pages/cops_lint.adoc

@@ -507,7 +507,7 @@ instead.
 OpenSSL::Cipher::AES.new(128, :GCM)
 
 # good
-OpenSSL::Cipher.new('AES-128-GCM')
+OpenSSL::Cipher.new('aes-128-gcm')
 ----
 
 [source,ruby]

lib/rubocop/cop/lint/deprecated_open_ssl_constant.rb

@@ -15,7 +15,7 @@ module Lint
       #   OpenSSL::Cipher::AES.new(128, :GCM)
       #
       #   # good
-      #   OpenSSL::Cipher.new('AES-128-GCM')
+      #   OpenSSL::Cipher.new('aes-128-gcm')
       #
       # @example
       #
@@ -127,9 +127,9 @@ def replacement_args(node)
         end
 
         def build_cipher_arguments(node, algorithm_name)
-          algorithm_parts = algorithm_name.split('-')
-          size_and_mode = sanitize_arguments(node.arguments)
-          "'#{(algorithm_parts + size_and_mode + ['CBC']).take(3).join('-')}'"
+          algorithm_parts = algorithm_name.downcase.split('-')
+          size_and_mode = sanitize_arguments(node.arguments).map(&:downcase)
+          "'#{(algorithm_parts + size_and_mode + ['cbc']).take(3).join('-')}'"
         end
       end
     end

spec/rubocop/cop/lint/deprecated_open_ssl_constant_spec.rb

@@ -8,61 +8,61 @@
   it 'registers an offense with cipher constant and two arguments and corrects' do
     expect_offense(<<~RUBY)
       OpenSSL::Cipher::AES.new(128, :GCM)
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('AES-128-GCM')` instead of `OpenSSL::Cipher::AES.new(128, :GCM)`.
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('aes-128-gcm')` instead of `OpenSSL::Cipher::AES.new(128, :GCM)`.
     RUBY
 
     expect_correction(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-GCM')
+      OpenSSL::Cipher.new('aes-128-gcm')
     RUBY
   end
 
   it 'registers an offense with cipher constant and one argument and corrects' do
     expect_offense(<<~RUBY)
       OpenSSL::Cipher::AES.new('128-GCM')
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('AES-128-GCM')` instead of `OpenSSL::Cipher::AES.new('128-GCM')`.
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('aes-128-gcm')` instead of `OpenSSL::Cipher::AES.new('128-GCM')`.
     RUBY
 
     expect_correction(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-GCM')
+      OpenSSL::Cipher.new('aes-128-gcm')
     RUBY
   end
 
   it 'registers an offense with cipher constant and double quoted string argument and corrects' do
     expect_offense(<<~RUBY)
       OpenSSL::Cipher::AES128.new("GCM")
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('AES-128-GCM')` instead of `OpenSSL::Cipher::AES128.new("GCM")`.
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('aes-128-gcm')` instead of `OpenSSL::Cipher::AES128.new("GCM")`.
     RUBY
 
     expect_correction(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-GCM')
+      OpenSSL::Cipher.new('aes-128-gcm')
     RUBY
   end
 
   it 'registers an offense with AES + blocksize constant and mode argument and corrects' do
     expect_offense(<<~RUBY)
       OpenSSL::Cipher::AES128.new(:GCM)
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('AES-128-GCM')` instead of `OpenSSL::Cipher::AES128.new(:GCM)`.
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('aes-128-gcm')` instead of `OpenSSL::Cipher::AES128.new(:GCM)`.
     RUBY
 
     expect_correction(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-GCM')
+      OpenSSL::Cipher.new('aes-128-gcm')
     RUBY
   end
 
   it 'registers an offense with AES + blocksize constant and corrects' do
     expect_offense(<<~RUBY)
       OpenSSL::Cipher::AES128.new
-      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('AES-128-CBC')` instead of `OpenSSL::Cipher::AES128.new`.
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `OpenSSL::Cipher.new('aes-128-cbc')` instead of `OpenSSL::Cipher::AES128.new`.
     RUBY
 
     expect_correction(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-CBC')
+      OpenSSL::Cipher.new('aes-128-cbc')
     RUBY
   end
 
   it 'does not register an offense when using cipher with a string' do
     expect_no_offenses(<<~RUBY)
-      OpenSSL::Cipher.new('AES-128-GCM')
+      OpenSSL::Cipher.new('aes-128-gcm')
     RUBY
   end