diff options
author | Douwe Maan <douwe@gitlab.com> | 2017-06-22 18:33:17 +0300 |
---|---|---|
committer | James Edwards-Jones <jedwardsjones@gitlab.com> | 2017-07-19 15:55:10 +0300 |
commit | 01694c1bd9ed66fbd690a92ab294da37d7f8aa1a (patch) | |
tree | 05f657bcc26c9a50e8135a84f64eaaf11569b018 /lib | |
parent | dd38cff3cfdb7e2006535e177813a71cc339ff18 (diff) |
Merge branch '24570-use-re2-for-user-supplied-regexp-9-3' into 'security-9-3'
24570 use re2 for user supplied regexp 9 3
See merge request !2129
Diffstat (limited to 'lib')
-rw-r--r-- | lib/gitlab/ci/trace/stream.rb | 4 | ||||
-rw-r--r-- | lib/gitlab/route_map.rb | 8 | ||||
-rw-r--r-- | lib/gitlab/untrusted_regexp.rb | 53 |
3 files changed, 61 insertions, 4 deletions
diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb index c4c0623df6c..5d6977106d6 100644 --- a/lib/gitlab/ci/trace/stream.rb +++ b/lib/gitlab/ci/trace/stream.rb @@ -69,12 +69,12 @@ module Gitlab return unless valid? return unless regex - regex = Regexp.new(regex) + regex = Gitlab::UntrustedRegexp.new(regex) match = "" reverse_line do |line| - matches = line.scan(regex) + matches = regex.scan(line) next unless matches.is_a?(Array) next if matches.empty? diff --git a/lib/gitlab/route_map.rb b/lib/gitlab/route_map.rb index 877aa6e6a28..f3952657983 100644 --- a/lib/gitlab/route_map.rb +++ b/lib/gitlab/route_map.rb @@ -18,7 +18,11 @@ module Gitlab mapping = @map.find { |mapping| mapping[:source] === path } return unless mapping - path.sub(mapping[:source], mapping[:public]) + if mapping[:source].is_a?(String) + path.sub(mapping[:source], mapping[:public]) + else + mapping[:source].replace(path, mapping[:public]) + end end private @@ -35,7 +39,7 @@ module Gitlab source_pattern = source_pattern[1...-1].gsub('\/', '/') begin - source_pattern = /\A#{source_pattern}\z/ + source_pattern = Gitlab::UntrustedRegexp.new('\A' + source_pattern + '\z') rescue RegexpError => e raise FormatError, "Route map entry source is not a valid regular expression: #{e}" end diff --git a/lib/gitlab/untrusted_regexp.rb b/lib/gitlab/untrusted_regexp.rb new file mode 100644 index 00000000000..8b43f0053d6 --- /dev/null +++ b/lib/gitlab/untrusted_regexp.rb @@ -0,0 +1,53 @@ +module Gitlab + # An untrusted regular expression is any regexp containing patterns sourced + # from user input. + # + # Ruby's built-in regular expression library allows patterns which complete in + # exponential time, permitting denial-of-service attacks. + # + # Not all regular expression features are available in untrusted regexes, and + # there is a strict limit on total execution time. See the RE2 documentation + # at https://github.com/google/re2/wiki/Syntax for more details. + class UntrustedRegexp + delegate :===, to: :regexp + + def initialize(pattern) + @regexp = RE2::Regexp.new(pattern, log_errors: false) + + raise RegexpError.new(regexp.error) unless regexp.ok? + end + + def replace_all(text, rewrite) + RE2.GlobalReplace(text, regexp, rewrite) + end + + def scan(text) + scan_regexp.scan(text).map do |match| + if regexp.number_of_capturing_groups == 0 + match.first + else + match + end + end + end + + def replace(text, rewrite) + RE2.Replace(text, regexp, rewrite) + end + + private + + attr_reader :regexp + + # RE2 scan operates differently to Ruby scan when there are no capture + # groups, so work around it + def scan_regexp + @scan_regexp ||= + if regexp.number_of_capturing_groups == 0 + RE2::Regexp.new('(' + regexp.source + ')') + else + regexp + end + end + end +end |