activerecord/lib/active_record/sanitization.rb
# frozen_string_literal: true
module ActiveRecord
module Sanitization
extend ActiveSupport::Concern
module ClassMethods
# Accepts an array of SQL conditions and sanitizes them into a valid
# SQL fragment for a WHERE clause.
#
# sanitize_sql_for_conditions(["name=? and group_id=?", "foo'bar", 4])
# # => "name='foo''bar' and group_id=4"
#
# sanitize_sql_for_conditions(["name=:name and group_id=:group_id", name: "foo'bar", group_id: 4])
# # => "name='foo''bar' and group_id='4'"
#
# sanitize_sql_for_conditions(["name='%s' and group_id='%s'", "foo'bar", 4])
# # => "name='foo''bar' and group_id='4'"
#
# This method will NOT sanitize an SQL string since it won't contain
# any conditions in it and will return the string as is.
#
# sanitize_sql_for_conditions("name='foo''bar' and group_id='4'")
# # => "name='foo''bar' and group_id='4'"
#
# Note that this sanitization method is not schema-aware, hence won't do any type casting
# and will directly use the database adapter's +quote+ method.
# For MySQL specifically this means that numeric parameters will be quoted as strings
# to prevent query manipulation attacks.
#
# sanitize_sql_for_conditions(["role = ?", 0])
# # => "role = '0'"
def sanitize_sql_for_conditions(condition)
return nil if condition.blank?
case condition
when Array; sanitize_sql_array(condition)
else condition
end
end
alias :sanitize_sql :sanitize_sql_for_conditions
# Accepts an array or hash of SQL conditions and sanitizes them into
# a valid SQL fragment for a SET clause.
#
# sanitize_sql_for_assignment(["name=? and group_id=?", nil, 4])
# # => "name=NULL and group_id=4"
#
# sanitize_sql_for_assignment(["name=:name and group_id=:group_id", name: nil, group_id: 4])
# # => "name=NULL and group_id=4"
#
# Post.sanitize_sql_for_assignment({ name: nil, group_id: 4 })
# # => "`posts`.`name` = NULL, `posts`.`group_id` = 4"
#
# This method will NOT sanitize an SQL string since it won't contain
# any conditions in it and will return the string as is.
#
# sanitize_sql_for_assignment("name=NULL and group_id='4'")
# # => "name=NULL and group_id='4'"
#
# Note that this sanitization method is not schema-aware, hence won't do any type casting
# and will directly use the database adapter's +quote+ method.
# For MySQL specifically this means that numeric parameters will be quoted as strings
# to prevent query manipulation attacks.
#
# sanitize_sql_for_assignment(["role = ?", 0])
# # => "role = '0'"
def sanitize_sql_for_assignment(assignments, default_table_name = table_name)
case assignments
when Array; sanitize_sql_array(assignments)
when Hash; sanitize_sql_hash_for_assignment(assignments, default_table_name)
else assignments
end
end
# Accepts an array, or string of SQL conditions and sanitizes
# them into a valid SQL fragment for an ORDER clause.
#
# sanitize_sql_for_order([Arel.sql("field(id, ?)"), [1,3,2]])
# # => "field(id, 1,3,2)"
#
# sanitize_sql_for_order("id ASC")
# # => "id ASC"
def sanitize_sql_for_order(condition)
if condition.is_a?(Array) && condition.first.to_s.include?("?")
disallow_raw_sql!(
[condition.first],
permit: adapter_class.column_name_with_order_matcher
)
# Ensure we aren't dealing with a subclass of String that might
# override methods we use (e.g. Arel::Nodes::SqlLiteral).
if condition.first.kind_of?(String) && !condition.first.instance_of?(String)
condition = [String.new(condition.first), *condition[1..-1]]
end
Arel.sql(sanitize_sql_array(condition))
else
condition
end
end
# Sanitizes a hash of attribute/value pairs into SQL conditions for a SET clause.
#
# sanitize_sql_hash_for_assignment({ status: nil, group_id: 1 }, "posts")
# # => "`posts`.`status` = NULL, `posts`.`group_id` = 1"
def sanitize_sql_hash_for_assignment(attrs, table)
c = connection
attrs.map do |attr, value|
type = type_for_attribute(attr)
value = type.serialize(type.cast(value))
"#{c.quote_table_name_for_assignment(table, attr)} = #{c.quote(value)}"
end.join(", ")
end
# Sanitizes a +string+ so that it is safe to use within an SQL
# LIKE statement. This method uses +escape_character+ to escape all
# occurrences of itself, "_" and "%".
#
# sanitize_sql_like("100% true!")
# # => "100\\% true!"
#
# sanitize_sql_like("snake_cased_string")
# # => "snake\\_cased\\_string"
#
# sanitize_sql_like("100% true!", "!")
# # => "100!% true!!"
#
# sanitize_sql_like("snake_cased_string", "!")
# # => "snake!_cased!_string"
def sanitize_sql_like(string, escape_character = "\\")
if string.include?(escape_character) && escape_character != "%" && escape_character != "_"
string = string.gsub(escape_character, '\0\0')
end
string.gsub(/(?=[%_])/, escape_character)
end
# Accepts an array of conditions. The array has each value
# sanitized and interpolated into the SQL statement. If using named bind
# variables in SQL statements where a colon is required verbatim use a
# backslash to escape.
#
# sanitize_sql_array(["name=? and group_id=?", "foo'bar", 4])
# # => "name='foo''bar' and group_id=4"
#
# sanitize_sql_array(["name=:name and group_id=:group_id", name: "foo'bar", group_id: 4])
# # => "name='foo''bar' and group_id=4"
#
# sanitize_sql_array(["TO_TIMESTAMP(:date, 'YYYY/MM/DD HH12\\:MI\\:SS')", date: "foo"])
# # => "TO_TIMESTAMP('foo', 'YYYY/MM/DD HH12:MI:SS')"
#
# sanitize_sql_array(["name='%s' and group_id='%s'", "foo'bar", 4])
# # => "name='foo''bar' and group_id='4'"
#
# Note that this sanitization method is not schema-aware, hence won't do any type casting
# and will directly use the database adapter's +quote+ method.
# For MySQL specifically this means that numeric parameters will be quoted as strings
# to prevent query manipulation attacks.
#
# sanitize_sql_array(["role = ?", 0])
# # => "role = '0'"
def sanitize_sql_array(ary)
statement, *values = ary
if values.first.is_a?(Hash) && /:\w+/.match?(statement)
with_connection do |c|
replace_named_bind_variables(c, statement, values.first)
end
elsif statement.include?("?")
with_connection do |c|
replace_bind_variables(c, statement, values)
end
elsif statement.blank?
statement
else
with_connection do |c|
statement % values.collect { |value| c.quote_string(value.to_s) }
end
end
end
def disallow_raw_sql!(args, permit: adapter_class.column_name_matcher) # :nodoc:
unexpected = nil
args.each do |arg|
next if arg.is_a?(Symbol) || Arel.arel_node?(arg) || permit.match?(arg.to_s.strip)
(unexpected ||= []) << arg
end
if unexpected
raise(ActiveRecord::UnknownAttributeReference,
"Dangerous query method (method whose arguments are used as raw " \
"SQL) called with non-attribute argument(s): " \
"#{unexpected.map(&:inspect).join(", ")}." \
"This method should not be called with user-provided values, such as request " \
"parameters or model attributes. Known-safe values can be passed " \
"by wrapping them in Arel.sql()."
)
end
end
private
def replace_bind_variables(connection, statement, values)
raise_if_bind_arity_mismatch(statement, statement.count("?"), values.size)
bound = values.dup
statement.gsub(/\?/) do
replace_bind_variable(connection, bound.shift)
end
end
def replace_bind_variable(connection, value)
if ActiveRecord::Relation === value
value.to_sql
else
quote_bound_value(connection, value)
end
end
def replace_named_bind_variables(connection, statement, bind_vars)
statement.gsub(/([:\\]?):([a-zA-Z]\w*)/) do |match|
if $1 == ":" # skip PostgreSQL casts
match # return the whole match
elsif $1 == "\\" # escaped literal colon
match[1..-1] # return match with escaping backlash char removed
elsif bind_vars.include?(match = $2.to_sym)
replace_bind_variable(connection, bind_vars[match])
else
raise PreparedStatementInvalid, "missing value for :#{match} in #{statement}"
end
end
end
def quote_bound_value(connection, value)
if value.respond_to?(:map) && !value.acts_like?(:string)
values = value.map { |v| v.respond_to?(:id_for_database) ? v.id_for_database : v }
if values.empty?
connection.quote(connection.cast_bound_value(nil))
else
values.map! { |v| connection.quote(connection.cast_bound_value(v)) }.join(",")
end
else
value = value.id_for_database if value.respond_to?(:id_for_database)
connection.quote(connection.cast_bound_value(value))
end
end
def raise_if_bind_arity_mismatch(statement, expected, provided)
unless expected == provided
raise PreparedStatementInvalid, "wrong number of bind variables (#{provided} for #{expected}) in: #{statement}"
end
end
end
end
end