diff options
-rw-r--r-- | lib/psych.rb | 76 | ||||
-rw-r--r-- | lib/psych/class_loader.rb | 4 | ||||
-rw-r--r-- | lib/psych/exception.rb | 4 | ||||
-rw-r--r-- | lib/psych/visitors/yaml_tree.rb | 46 | ||||
-rw-r--r-- | test/psych/test_psych.rb | 57 |
5 files changed, 182 insertions, 5 deletions
diff --git a/lib/psych.rb b/lib/psych.rb index 7c6b8d0..72276d9 100644 --- a/lib/psych.rb +++ b/lib/psych.rb @@ -282,7 +282,8 @@ module Psych # * TrueClass # * FalseClass # * NilClass - # * Numeric + # * Integer + # * Float # * String # * Array # * Hash @@ -513,6 +514,79 @@ module Psych end ### + # call-seq: + # Psych.safe_dump(o) -> string of yaml + # Psych.safe_dump(o, options) -> string of yaml + # Psych.safe_dump(o, io) -> io object passed in + # Psych.safe_dump(o, io, options) -> io object passed in + # + # Safely dump Ruby object +o+ to a YAML string. Optional +options+ may be passed in + # to control the output format. If an IO object is passed in, the YAML will + # be dumped to that IO object. By default, only the following + # classes are allowed to be serialized: + # + # * TrueClass + # * FalseClass + # * NilClass + # * Integer + # * Float + # * String + # * Array + # * Hash + # + # Arbitrary classes can be allowed by adding those classes to the +permitted_classes+ + # keyword argument. They are additive. For example, to allow Date serialization: + # + # Psych.safe_dump(yaml, permitted_classes: [Date]) + # + # Now the Date class can be dumped in addition to the classes listed above. + # + # A Psych::DisallowedClass exception will be raised if the object contains a + # class that isn't in the +permitted_classes+ list. + # + # Currently supported options are: + # + # [<tt>:indentation</tt>] Number of space characters used to indent. + # Acceptable value should be in <tt>0..9</tt> range, + # otherwise option is ignored. + # + # Default: <tt>2</tt>. + # [<tt>:line_width</tt>] Max character to wrap line at. + # + # Default: <tt>0</tt> (meaning "wrap at 81"). + # [<tt>:canonical</tt>] Write "canonical" YAML form (very verbose, yet + # strictly formal). + # + # Default: <tt>false</tt>. + # [<tt>:header</tt>] Write <tt>%YAML [version]</tt> at the beginning of document. + # + # Default: <tt>false</tt>. + # + # Example: + # + # # Dump an array, get back a YAML string + # Psych.safe_dump(['a', 'b']) # => "---\n- a\n- b\n" + # + # # Dump an array to an IO object + # Psych.safe_dump(['a', 'b'], StringIO.new) # => #<StringIO:0x000001009d0890> + # + # # Dump an array with indentation set + # Psych.safe_dump(['a', ['b']], indentation: 3) # => "---\n- a\n- - b\n" + # + # # Dump an array to an IO with indentation set + # Psych.safe_dump(['a', ['b']], StringIO.new, indentation: 3) + def self.safe_dump o, io = nil, options = {} + if Hash === io + options = io + io = nil + end + + visitor = Psych::Visitors::RestrictedYAMLTree.create options + visitor << o + visitor.tree.yaml io, options + end + + ### # Dump a list of objects as separate documents to a document stream. # # Example: diff --git a/lib/psych/class_loader.rb b/lib/psych/class_loader.rb index a5d1a7a..088373c 100644 --- a/lib/psych/class_loader.rb +++ b/lib/psych/class_loader.rb @@ -86,7 +86,7 @@ module Psych if @symbols.include? sym super else - raise DisallowedClass, 'Symbol' + raise DisallowedClass.new('load', 'Symbol') end end @@ -96,7 +96,7 @@ module Psych if @classes.include? klassname super else - raise DisallowedClass, klassname + raise DisallowedClass.new('load', klassname) end end end diff --git a/lib/psych/exception.rb b/lib/psych/exception.rb index fac0c42..f473b95 100644 --- a/lib/psych/exception.rb +++ b/lib/psych/exception.rb @@ -7,8 +7,8 @@ module Psych end class DisallowedClass < Exception - def initialize klass_name - super "Tried to load unspecified class: #{klass_name}" + def initialize action, klass_name + super "Tried to #{action} unspecified class: #{klass_name}" end end end diff --git a/lib/psych/visitors/yaml_tree.rb b/lib/psych/visitors/yaml_tree.rb index bf7c0bb..05748dd 100644 --- a/lib/psych/visitors/yaml_tree.rb +++ b/lib/psych/visitors/yaml_tree.rb @@ -535,5 +535,51 @@ module Psych end end end + + class RestrictedYAMLTree < YAMLTree + DEFAULT_PERMITTED_CLASSES = { + TrueClass => true, + FalseClass => true, + NilClass => true, + Integer => true, + Float => true, + String => true, + Array => true, + Hash => true, + }.compare_by_identity.freeze + + def initialize emitter, ss, options + super + @permitted_classes = DEFAULT_PERMITTED_CLASSES.dup + Array(options[:permitted_classes]).each do |klass| + @permitted_classes[klass] = true + end + @permitted_symbols = {}.compare_by_identity + Array(options[:permitted_symbols]).each do |symbol| + @permitted_symbols[symbol] = true + end + @aliases = options.fetch(:aliases, false) + end + + def accept target + if !@aliases && @st.key?(target) + raise BadAlias, "Tried to dump an aliased object" + end + + unless @permitted_classes[target.class] + raise DisallowedClass.new('dump', target.class.name || target.class.inspect) + end + + super + end + + def visit_Symbol sym + unless @permitted_symbols[sym] + raise DisallowedClass.new('dump', "Symbol(#{sym.inspect})") + end + + super + end + end end end diff --git a/test/psych/test_psych.rb b/test/psych/test_psych.rb index 256ed91..c9d39c5 100644 --- a/test/psych/test_psych.rb +++ b/test/psych/test_psych.rb @@ -381,4 +381,61 @@ hoge: result = Psych.safe_load(yaml, symbolize_names: true) assert_equal result, { foo: { bar: "baz", 1 => 2 }, hoge: [{ fuga: "piyo" }] } end + + def test_safe_dump_defaults + yaml = <<-eoyml +--- +array: +- 1 +float: 13.12 +booleans: +- true +- false +eoyml + + payload = YAML.safe_dump({ + "array" => [1], + "float" => 13.12, + "booleans" => [true, false], + }) + assert_equal yaml, payload + end + + def test_safe_dump_unpermitted_class + error = assert_raises Psych::DisallowedClass do + YAML.safe_dump(Object.new) + end + assert_equal "Tried to dump unspecified class: Object", error.message + + hash_subclass = Class.new(Hash) + error = assert_raises Psych::DisallowedClass do + YAML.safe_dump(hash_subclass.new) + end + assert_equal "Tried to dump unspecified class: #{hash_subclass.inspect}", error.message + end + + def test_safe_dump_extra_permitted_classes + assert_equal "--- !ruby/object {}\n", YAML.safe_dump(Object.new, permitted_classes: [Object]) + end + + def test_safe_dump_symbols + error = assert_raises Psych::DisallowedClass do + YAML.safe_dump(:foo, permitted_classes: [Symbol]) + end + assert_equal "Tried to dump unspecified class: Symbol(:foo)", error.message + + assert_equal "--- :foo\n", YAML.safe_dump(:foo, permitted_classes: [Symbol], permitted_symbols: [:foo]) + end + + def test_safe_dump_aliases + x = [] + x << x + error = assert_raises Psych::BadAlias do + YAML.safe_dump(x) + end + assert_equal "Tried to dump an aliased object", error.message + + assert_equal "--- &1\n" + "- *1\n", YAML.safe_dump(x, aliases: true) + end + end |