Module: Safemode

Defined in:

lib/safemode.rb,
lib/safemode/jail.rb,
lib/safemode/scope.rb,
lib/safemode/parser.rb,
lib/safemode/blankslate.rb,
lib/safemode/core_jails.rb,
lib/safemode/exceptions.rb

Defined Under Namespace

Classes: Blankslate, Box, Error, Jail, NoMethodError, Parser, Scope, SecurityError

Constant Summary

@@default_methods =

these methods are allowed in all classes if they are present

%w( % & * ** + +@ - -@ / < << <= <=> ! != == === > >= >> ^ | ~
eql? equal? new methods is_a? kind_of? nil?
[] []= to_a to_jail to_s inspect to_param not freeze)

@@methods_whitelist =

whitelisted methods for core classes … kind of arbitrary selection

{
  'Array'      => %w(any? assoc at blank? collect collect! compact compact!
                  concat delete delete_at delete_if each each_index empty?
                  fetch fill first flatten flatten! hash include? index
                  indexes indices inject insert join last length map map!
                  nitems pop push present? rassoc reject reject! reverse
                  reverse! reverse_each rindex select shift size slice
                  slice! sort sort! transpose uniq uniq! unshift values_at
                  zip),
   'Bignum'     => %w(abs blank? ceil chr coerce div divmod downto floor hash
                  integer? modulo next nonzero? present? quo remainder round
                  singleton_method_added size step succ times to_f to_i
                  to_int to_s truncate upto zero?),
   'Fixnum'     => %w(abs blank? ceil chr coerce div divmod downto floor id2name
                  integer? modulo modulo next nonzero? present? quo remainder
                  round singleton_method_added size step succ times to_f to_i
                  to_int to_s to_sym truncate upto zero?),
   'Float'      => %w(abs blank? ceil coerce div divmod finite? floor hash
                  infinite? integer? modulo nan? nonzero? present? quo
                  remainder round singleton_method_added step to_f to_i
                  to_int to_s truncate zero?),
   'Hash'       => %w(any? blank? clear delete delete_if each each_key
                  each_pair each_value empty? fetch has_key? has_value?
                  include? index invert key? keys length member? merge merge!
                  present? rec_merge! rehash reject reject! select shift
                  size sort store update value? values values_at),
   'Integer'    => %w(abs blank? ceil chr coerce div divmod downto floor id2name
                  integer? modulo modulo next nonzero? present? quo remainder
                  round singleton_method_added size step succ times to_f to_i
                  to_int to_s to_sym truncate upto zero?),
   'Range'      => %w(any? begin blank? each end exclude_end? first hash
                  include? include_without_range? last member? present?
                  step),
   'String'     => %w(blank? capitalize capitalize! casecmp center chomp chomp!
                  chop chop! concat count crypt delete delete! downcase
                  downcase! dump each_byte each_line empty? end_with?
                  force_encoding gsub gsub! hash hex include? index insert
                  intern iseuc issjis isutf8 kconv length ljust lstrip
                  lstrip! match next next! oct present? reverse reverse!
                  rindex rjust rstrip rstrip! scan size slice slice! split
                  squeeze squeeze! start_with? strip strip! sub sub! succ
                  succ! sum swapcase swapcase! to_f to_i to_str to_sym to_xs
                  toeuc tojis tosjis toutf16 toutf8 tr tr! tr_s tr_s! upcase
                  upcase! upto),
   'Symbol'     => %w(blank? present? to_i to_int),
   'Time'       => %w(blank? _dump asctime ctime day dst? getgm getlocal
                  getutc gmt? gmt_offset gmtime gmtoff hash hour httpdate
                  isdst iso8601 localtime mday min minus_without_duration mon
                  month plus_without_duration present? rfc2822 rfc822 sec
                  strftime succ to_date to_datetime to_f to_i tv_sec tv_usec
                  usec utc utc? utc_offset wday xmlschema yday year zone
                  to_formatted_s),
   'Date'       => %w(ajd amjd asctime blank? ctime cwday cweek cwyear day
                  day_fraction default_inspect downto england gregorian
                  gregorian? hash italy jd julian julian? ld leap? mday
                  minus_without_duration mjd mon month new_start newsg next
                  ns? os? plus_without_duration present? sg start step
                  strftime succ upto wday yday year),
   'DateTime'   => %w(blank? hour min new_offset newof of offset present? sec
                  sec_fraction strftime to_datetime_default_s to_json zone),
   'NilClass'   => %w(blank? duplicable? present? to_f to_i),
   'FalseClass' => %w(blank? duplicable? present?),
   'TrueClass'  => %w(blank? duplicable? present?)
}

@@default_class_methods =

these class methods are allowed on all classes if they are present

%w(name to_jail to_s)

@@class_methods_whitelist =

whitelisted class methods for core classes

{
  'String' => %w(new)
}

Class Method Summary

• .core_classes ⇒ Object
• .core_jail_class_methods(klass) ⇒ Object
• .core_jail_methods(klass) ⇒ Object
• .define_core_jail_classes ⇒ Object
• .define_jail_class(klass) ⇒ Object
• .find_jail_class(klass) ⇒ Object
• .jail(obj) ⇒ Object

Class Method Details

.core_classes ⇒ Object

# File 'lib/safemode/core_jails.rb', line 19

def core_classes
  klasses = [ Array, Float, Hash, Range, String, Symbol, Time, NilClass, FalseClass, TrueClass ]
  klasses << Date if defined? Date
  klasses << DateTime if defined? DateTime
  if RUBY_VERSION >= '2.4.0'
    klasses << Integer
  else
    klasses << Bignum
    klasses << Fixnum
  end
  klasses
end

.core_jail_class_methods(klass) ⇒ Object

# File 'lib/safemode/core_jails.rb', line 36

def core_jail_class_methods(klass)
  @@class_methods_whitelist.fetch(klass.name, []) + (@@default_class_methods & klass.methods.map(&:to_s))
end

.core_jail_methods(klass) ⇒ Object

# File 'lib/safemode/core_jails.rb', line 32

def core_jail_methods(klass)
  @@methods_whitelist.fetch(klass.name, []) + (@@default_methods & klass.instance_methods.map(&:to_s))
end

.define_core_jail_classes ⇒ Object

# File 'lib/safemode/core_jails.rb', line 3

def define_core_jail_classes
  core_classes.each do |klass|
    jail = define_jail_class(klass)
    jail.allow_instance_method *core_jail_methods(klass).uniq
    jail.allow_class_method *core_jail_class_methods(klass).uniq
    jail
  end
end

.define_jail_class(klass) ⇒ Object

# File 'lib/safemode/core_jails.rb', line 12

def define_jail_class(klass)
  unless klass.const_defined?("Jail")
    klass.const_set("Jail", jail = Class.new(Safemode::Jail))
  end
  klass.const_get('Jail')
end

.find_jail_class(klass) ⇒ Object

# File 'lib/safemode.rb', line 30

def find_jail_class(klass)
  while klass != Object
    return klass.const_get('Jail') if klass.const_defined?('Jail')
    klass = klass.superclass
  end
  Jail
end

.jail(obj) ⇒ Object

# File 'lib/safemode.rb', line 26

def jail(obj)
  find_jail_class(obj.is_a?(Class) ? obj : obj.class).new obj
end