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-rw-r--r--ext/psych/lib/psych.rb76
-rw-r--r--ext/psych/lib/psych/class_loader.rb4
-rw-r--r--ext/psych/lib/psych/exception.rb4
-rw-r--r--ext/psych/lib/psych/visitors/yaml_tree.rb46
-rw-r--r--test/psych/test_psych.rb57
5 files changed, 182 insertions, 5 deletions
diff --git a/ext/psych/lib/psych.rb b/ext/psych/lib/psych.rb
index 6205061d0b5..1efe8d5f620 100644
--- a/ext/psych/lib/psych.rb
+++ b/ext/psych/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/ext/psych/lib/psych/class_loader.rb b/ext/psych/lib/psych/class_loader.rb
index a5d1a7a4a92..088373cd669 100644
--- a/ext/psych/lib/psych/class_loader.rb
+++ b/ext/psych/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/ext/psych/lib/psych/exception.rb b/ext/psych/lib/psych/exception.rb
index fac0c42b9fb..f473b95a3bb 100644
--- a/ext/psych/lib/psych/exception.rb
+++ b/ext/psych/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/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index bf7c0bb8ca9..05748dd81cb 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/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 256ed9110cf..c9d39c5810a 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