Merge pull request #95 from merefield/improve_safe_ruby

Improve safe ruby

lib/discourse_chatbot/safe_ruby/lib/constant_whitelist.rb

@@ -1,15 +1,16 @@
 # frozen_string_literal: true
-
-ALLOWED_CONSTANTS= [
-  :Object, :Module, :Class, :BasicObject, :Kernel, :NilClass, :NIL, :Data, :TrueClass, :TRUE, :FalseClass, :FALSE, :Encoding, 
-  :Comparable, :Enumerable, :String, :Symbol, :Exception, :SystemExit, :SignalException, :Interrupt, :StandardError, :TypeError,
-  :ArgumentError, :IndexError, :KeyError, :RangeError, :ScriptError, :SyntaxError, :LoadError, :NotImplementedError, :NameError,
-  :NoMethodError, :RuntimeError, :SecurityError, :NoMemoryError, :EncodingError, :SystemCallError, :Errno, :ZeroDivisionError,
-  :FloatDomainError, :Numeric, :Integer, :Fixnum, :Float, :Bignum, :Array, :Hash,  :Struct, :RegexpError, :Regexp,
-  :MatchData, :Marshal, :Range, :IOError, :EOFError, :IO, :STDIN, :STDOUT, :STDERR, :Time, :Random,
-  :Signal, :Proc, :LocalJumpError, :SystemStackError, :Method, :UnboundMethod, :Binding, :Math, :Enumerator,
-  :StopIteration, :RubyVM, :Thread, :TOPLEVEL_BINDING, :ThreadGroup, :Mutex, :ThreadError, :Fiber, :FiberError, :Rational, :Complex,
-  :RUBY_VERSION, :RUBY_RELEASE_DATE, :RUBY_PLATFORM, :RUBY_PATCHLEVEL, :RUBY_REVISION, :RUBY_DESCRIPTION, :RUBY_COPYRIGHT, :RUBY_ENGINE,
-  :TracePoint, :ARGV, :Gem, :RbConfig, :Config, :CROSS_COMPILING, :Date, :ConditionVariable, :Queue, :SizedQueue, :MonitorMixin, :Monitor,
-  :Exception2MessageMapper, :IRB, :RubyToken, :RubyLex, :Readline, :RUBYGEMS_ACTIVATION_MONITOR
-]
+class SafeRuby
+  ALLOWED_CONSTANTS= [
+    :Object, :Module, :Class, :BasicObject, :Kernel, :NilClass, :NIL, :Data, :TrueClass, :TRUE, :FalseClass, :FALSE, :Encoding, 
+    :Comparable, :Enumerable, :String, :Symbol, :Exception, :SystemExit, :SignalException, :Interrupt, :StandardError, :TypeError,
+    :ArgumentError, :IndexError, :KeyError, :RangeError, :ScriptError, :SyntaxError, :LoadError, :NotImplementedError, :NameError,
+    :NoMethodError, :RuntimeError, :SecurityError, :NoMemoryError, :EncodingError, :SystemCallError, :Errno, :ZeroDivisionError,
+    :FloatDomainError, :Numeric, :Integer, :Fixnum, :Float, :Bignum, :Array, :Hash,  :Struct, :RegexpError, :Regexp,
+    :MatchData, :Marshal, :Range, :IOError, :EOFError, :IO, :STDIN, :STDOUT, :STDERR, :Time, :Random,
+    :Signal, :Proc, :LocalJumpError, :SystemStackError, :Method, :UnboundMethod, :Binding, :Math, :Enumerator,
+    :StopIteration, :RubyVM, :Thread, :TOPLEVEL_BINDING, :ThreadGroup, :Mutex, :ThreadError, :Fiber, :FiberError, :Rational, :Complex,
+    :RUBY_VERSION, :RUBY_RELEASE_DATE, :RUBY_PLATFORM, :RUBY_PATCHLEVEL, :RUBY_REVISION, :RUBY_DESCRIPTION, :RUBY_COPYRIGHT, :RUBY_ENGINE,
+    :TracePoint, :ARGV, :Gem, :RbConfig, :Config, :CROSS_COMPILING, :Date, :ConditionVariable, :Queue, :SizedQueue, :MonitorMixin, :Monitor,
+    :Exception2MessageMapper, :IRB, :RubyToken, :RubyLex, :Readline, :RUBYGEMS_ACTIVATION_MONITOR
+  ]
+end

lib/discourse_chatbot/safe_ruby/lib/make_safe_code.rb

@@ -1,53 +1,54 @@
 # frozen_string_literal: true
+class SafeRuby
+  MAKE_SAFE_CODE = <<-STRING
+  def keep_singleton_methods(klass, singleton_methods)
+    klass = Object.const_get(klass)
+    singleton_methods = singleton_methods.map(&:to_sym)
+    undef_methods = (klass.singleton_methods - singleton_methods)
 
-MAKE_SAFE_CODE = <<-STRING
-def keep_singleton_methods(klass, singleton_methods)
-  klass = Object.const_get(klass)
-  singleton_methods = singleton_methods.map(&:to_sym)
-  undef_methods = (klass.singleton_methods - singleton_methods)
+    undef_methods.each do |method|
+      klass.singleton_class.send(:undef_method, method)
+    end
 
-  undef_methods.each do |method|
-    klass.singleton_class.send(:undef_method, method)
   end
 
-end
+  def keep_methods(klass, methods)
+    klass = Object.const_get(klass)
+    methods = methods.map(&:to_sym)
+    undef_methods = (klass.methods(false) - methods)
+    undef_methods.each do |method|
+      klass.send(:undef_method, method)
+    end
+  end
 
-def keep_methods(klass, methods)
-  klass = Object.const_get(klass)
-  methods = methods.map(&:to_sym)
-  undef_methods = (klass.methods(false) - methods)
-  undef_methods.each do |method|
-    klass.send(:undef_method, method)
+  def clean_constants
+    (Object.constants - #{ALLOWED_CONSTANTS}).each do |const|
+      Object.send(:remove_const, const) if defined?(const)
+    end
   end
-end
 
-def clean_constants
-  (Object.constants - #{ALLOWED_CONSTANTS}).each do |const|
-    Object.send(:remove_const, const) if defined?(const)
+  keep_singleton_methods(:Kernel, #{KERNEL_S_METHODS})
+  keep_singleton_methods(:Symbol, #{SYMBOL_S_METHODS})
+  keep_singleton_methods(:String, #{STRING_S_METHODS})
+  keep_singleton_methods(:IO, #{IO_S_METHODS})
+
+  keep_methods(:Kernel, #{KERNEL_METHODS})
+  keep_methods(:NilClass, #{NILCLASS_METHODS})
+  keep_methods(:TrueClass, #{TRUECLASS_METHODS})
+  keep_methods(:FalseClass, #{FALSECLASS_METHODS})
+  keep_methods(:Enumerable, #{ENUMERABLE_METHODS})
+  keep_methods(:String, #{STRING_METHODS})
+  Kernel.class_eval do
+  def `(*args)
+    raise NoMethodError, "` is unavailable"
   end
-end
 
-keep_singleton_methods(:Kernel, #{KERNEL_S_METHODS})
-keep_singleton_methods(:Symbol, #{SYMBOL_S_METHODS})
-keep_singleton_methods(:String, #{STRING_S_METHODS})
-keep_singleton_methods(:IO, #{IO_S_METHODS})
-
-keep_methods(:Kernel, #{KERNEL_METHODS})
-keep_methods(:NilClass, #{NILCLASS_METHODS})
-keep_methods(:TrueClass, #{TRUECLASS_METHODS})
-keep_methods(:FalseClass, #{FALSECLASS_METHODS})
-keep_methods(:Enumerable, #{ENUMERABLE_METHODS})
-keep_methods(:String, #{STRING_METHODS})
-Kernel.class_eval do
- def `(*args)
-   raise NoMethodError, "` is unavailable"
- end
-
- def system(*args)
-   raise NoMethodError, "system is unavailable"
- end
-end
+  def system(*args)
+    raise NoMethodError, "system is unavailable"
+  end
+  end
 
-clean_constants
+  clean_constants
 
-STRING
+  STRING
+end