63 lines
2.0 KiB
Ruby
63 lines
2.0 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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class UntrustedRegexp
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# This class implements support for Ruby syntax of regexps
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# and converts that to RE2 representation:
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# /<regexp>/<flags>
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class RubySyntax
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PATTERN = %r{^/(?<regexp>.*)/(?<flags>[ismU]*)$}.freeze
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# Checks if pattern matches a regexp pattern
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# but does not enforce it's validity
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def self.matches_syntax?(pattern)
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pattern.is_a?(String) && pattern.match(PATTERN).present?
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end
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# The regexp can match the pattern `/.../`, but may not be fabricatable:
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# it can be invalid or incomplete: `/match ( string/`
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def self.valid?(pattern, fallback: false)
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!!self.fabricate(pattern, fallback: fallback)
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end
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def self.fabricate(pattern, fallback: false)
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self.fabricate!(pattern, fallback: fallback)
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rescue RegexpError
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nil
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end
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def self.fabricate!(pattern, fallback: false)
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raise RegexpError, 'Pattern is not string!' unless pattern.is_a?(String)
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matches = pattern.match(PATTERN)
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raise RegexpError, 'Invalid regular expression!' if matches.nil?
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begin
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create_untrusted_regexp(matches[:regexp], matches[:flags])
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rescue RegexpError
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raise unless fallback &&
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Feature.enabled?(:allow_unsafe_ruby_regexp, default_enabled: false)
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create_ruby_regexp(matches[:regexp], matches[:flags])
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end
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end
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def self.create_untrusted_regexp(pattern, flags)
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pattern.prepend("(?#{flags})") if flags.present?
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UntrustedRegexp.new(pattern, multiline: false)
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end
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private_class_method :create_untrusted_regexp
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def self.create_ruby_regexp(pattern, flags)
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options = 0
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options += Regexp::IGNORECASE if flags&.include?('i')
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options += Regexp::MULTILINE if flags&.include?('m')
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Regexp.new(pattern, options)
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end
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private_class_method :create_ruby_regexp
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end
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end
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end
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