1	# frozen_string_literal: true
2
3	module ActiveRecord
4	module Sanitization
5	extend ActiveSupport::Concern
6
7	module ClassMethods
8	private
9
10	# Accepts an array or string of SQL conditions and sanitizes
11	# them into a valid SQL fragment for a WHERE clause.
12	#
13	# sanitize_sql_for_conditions(["name=? and group_id=?", "foo'bar", 4])
14	# # => "name='foo''bar' and group_id=4"
15	#
16	# sanitize_sql_for_conditions(["name=:name and group_id=:group_id", name: "foo'bar", group_id: 4])
17	# # => "name='foo''bar' and group_id='4'"
18	#
19	# sanitize_sql_for_conditions(["name='%s' and group_id='%s'", "foo'bar", 4])
20	# # => "name='foo''bar' and group_id='4'"
21	#
22	# sanitize_sql_for_conditions("name='foo''bar' and group_id='4'")
23	# # => "name='foo''bar' and group_id='4'"
24	def sanitize_sql_for_conditions(condition) # :doc:
25	return nil if condition.blank?
26
27	case condition
28	when Array; sanitize_sql_array(condition)
29	else condition
30	end
31	end
32	alias :sanitize_sql :sanitize_sql_for_conditions
33
34	# Accepts an array, hash, or string of SQL conditions and sanitizes
35	# them into a valid SQL fragment for a SET clause.
36	#
37	# sanitize_sql_for_assignment(["name=? and group_id=?", nil, 4])
38	# # => "name=NULL and group_id=4"
39	#
40	# sanitize_sql_for_assignment(["name=:name and group_id=:group_id", name: nil, group_id: 4])
41	# # => "name=NULL and group_id=4"
42	#
43	# Post.send(:sanitize_sql_for_assignment, { name: nil, group_id: 4 })
44	# # => "`posts`.`name` = NULL, `posts`.`group_id` = 4"
45	#
46	# sanitize_sql_for_assignment("name=NULL and group_id='4'")
47	# # => "name=NULL and group_id='4'"
48	def sanitize_sql_for_assignment(assignments, default_table_name = table_name) # :doc:
49	case assignments
50	when Array; sanitize_sql_array(assignments)
51	when Hash; sanitize_sql_hash_for_assignment(assignments, default_table_name)
52	else assignments
53	end
54	end
55
56	# Accepts an array, or string of SQL conditions and sanitizes
57	# them into a valid SQL fragment for an ORDER clause.
58	#
59	# sanitize_sql_for_order(["field(id, ?)", [1,3,2]])
60	# # => "field(id, 1,3,2)"
61	#
62	# sanitize_sql_for_order("id ASC")
63	# # => "id ASC"
64	def sanitize_sql_for_order(condition) # :doc:
65	if condition.is_a?(Array) && condition.first.to_s.include?("?")
66	enforce_raw_sql_whitelist([condition.first],
67	whitelist: AttributeMethods::ClassMethods::COLUMN_NAME_ORDER_WHITELIST
68	)
69
70	# Ensure we aren't dealing with a subclass of String that might
71	# override methods we use (eg. Arel::Nodes::SqlLiteral).
72	if condition.first.kind_of?(String) && !condition.first.instance_of?(String)
73	condition = [String.new(condition.first), *condition[1..-1]]
74	end
75
76	Arel.sql(sanitize_sql_array(condition))
77	else
78	condition
79	end
80	end
81
82	# Accepts a hash of SQL conditions and replaces those attributes
83	# that correspond to a {#composed_of}[rdoc-ref:Aggregations::ClassMethods#composed_of]
84	# relationship with their expanded aggregate attribute values.
85	#
86	# Given:
87	#
88	# class Person < ActiveRecord::Base
89	# composed_of :address, class_name: "Address",
90	# mapping: [%w(address_street street), %w(address_city city)]
91	# end
92	#
93	# Then:
94	#
95	# { address: Address.new("813 abc st.", "chicago") }
96	# # => { address_street: "813 abc st.", address_city: "chicago" }
97	def expand_hash_conditions_for_aggregates(attrs) # :doc:
98	expanded_attrs = {}
99	attrs.each do |attr, value|
100	if aggregation = reflect_on_aggregation(attr.to_sym)
101	mapping = aggregation.mapping
102	mapping.each do |field_attr, aggregate_attr|
103	if mapping.size == 1 && !value.respond_to?(aggregate_attr)
104	expanded_attrs[field_attr] = value
105	else
106	expanded_attrs[field_attr] = value.send(aggregate_attr)
107	end
108	end
109	else
110	expanded_attrs[attr] = value
111	end
112	end
113	expanded_attrs
114	end
115
116	# Sanitizes a hash of attribute/value pairs into SQL conditions for a SET clause.
117	#
118	# sanitize_sql_hash_for_assignment({ status: nil, group_id: 1 }, "posts")
119	# # => "`posts`.`status` = NULL, `posts`.`group_id` = 1"
120	def sanitize_sql_hash_for_assignment(attrs, table) # :doc:
121	c = connection
122	attrs.map do |attr, value|
123	type = type_for_attribute(attr.to_s)
124	value = type.serialize(type.cast(value))
125	"#{c.quote_table_name_for_assignment(table, attr)} = #{c.quote(value)}"
126	end.join(", ")
127	end
128
129	# Sanitizes a +string+ so that it is safe to use within an SQL
130	# LIKE statement. This method uses +escape_character+ to escape all occurrences of "\", "_" and "%".
131	#
132	# sanitize_sql_like("100%")
133	# # => "100\\%"
134	#
135	# sanitize_sql_like("snake_cased_string")
136	# # => "snake\\_cased\\_string"
137	#
138	# sanitize_sql_like("100%", "!")
139	# # => "100!%"
140	#
141	# sanitize_sql_like("snake_cased_string", "!")
142	# # => "snake!_cased!_string"
143	def sanitize_sql_like(string, escape_character = "\\") # :doc:
144	pattern = Regexp.union(escape_character, "%", "_")
145	string.gsub(pattern) { |x| [escape_character, x].join }
146	end
147
148	# Accepts an array of conditions. The array has each value
149	# sanitized and interpolated into the SQL statement.
150	#
151	# sanitize_sql_array(["name=? and group_id=?", "foo'bar", 4])
152	# # => "name='foo''bar' and group_id=4"
153	#
154	# sanitize_sql_array(["name=:name and group_id=:group_id", name: "foo'bar", group_id: 4])
155	# # => "name='foo''bar' and group_id=4"
156	#
157	# sanitize_sql_array(["name='%s' and group_id='%s'", "foo'bar", 4])
158	# # => "name='foo''bar' and group_id='4'"
159	def sanitize_sql_array(ary) # :doc:
160	statement, *values = ary
161	if values.first.is_a?(Hash) && /:\w+/.match?(statement)
162	replace_named_bind_variables(statement, values.first)
163	elsif statement.include?("?")
164	replace_bind_variables(statement, values)
165	elsif statement.blank?
166	statement
167	else
168	statement % values.collect { |value| connection.quote_string(value.to_s) }
169	end
170	end
171
172	def replace_bind_variables(statement, values)
173	raise_if_bind_arity_mismatch(statement, statement.count("?"), values.size)
174	bound = values.dup
175	c = connection
176	statement.gsub(/\?/) do
177	replace_bind_variable(bound.shift, c)
178	end
179	end
180
181	def replace_bind_variable(value, c = connection)
182	if ActiveRecord::Relation === value
183	value.to_sql
184	else
185	quote_bound_value(value, c)
186	end
187	end
188
189	def replace_named_bind_variables(statement, bind_vars)
190	statement.gsub(/(:?):([a-zA-Z]\w*)/) do |match|
191	if $1 == ":" # skip postgresql casts
192	match # return the whole match
193	elsif bind_vars.include?(match = $2.to_sym)
194	replace_bind_variable(bind_vars[match])
195	else
196	raise PreparedStatementInvalid, "missing value for :#{match} in #{statement}"
197	end
198	end
199	end
200
201	def quote_bound_value(value, c = connection)
202	if value.respond_to?(:map) && !value.acts_like?(:string)
203	if value.respond_to?(:empty?) && value.empty?
204	c.quote(nil)
205	else
206	value.map { |v| c.quote(v) }.join(",")
207	end
208	else
209	c.quote(value)
210	end
211	end
212
213	def raise_if_bind_arity_mismatch(statement, expected, provided)
214	unless expected == provided
215	raise PreparedStatementInvalid, "wrong number of bind variables (#{provided} for #{expected}) in: #{statement}"
216	end
217	end
218	end
219	end
220	end