Make CI refs matching to to use UntrustedRegexp

This makes ref validation to use always `UntrustedRegexp`.
This also splits the existing RubySyntax into separate
class.

2 files changed, 8 insertions, 14 deletions

diff --git a/lib/gitlab/config/entry/legacy_validation_helpers.rb b/lib/gitlab/config/entry/legacy_validation_helpers.rb
index d3ab5625743..0a629075302 100644
--- a/lib/gitlab/config/entry/legacy_validation_helpers.rb
+++ b/lib/gitlab/config/entry/legacy_validation_helpers.rb
@@ -45,17 +45,15 @@ module Gitlab
         end
 
         def validate_regexp(value)
-          !value.nil? && Regexp.new(value.to_s) && true
-        rescue RegexpError, TypeError
-          false
+          Gitlab::UntrustedRegexp::RubySyntax.valid?(value)
         end
 
         def validate_string_or_regexp(value)
           return true if value.is_a?(Symbol)
           return false unless value.is_a?(String)
 
-          if value.first == '/' && value.last == '/'
-            validate_regexp(value[1...-1])
+          if Gitlab::UntrustedRegexp::RubySyntax.matches_syntax?(value)
+            validate_regexp(value)
           else
             true
           end
diff --git a/lib/gitlab/config/entry/validators.rb b/lib/gitlab/config/entry/validators.rb
index 25bfa50f829..d348e11b753 100644
--- a/lib/gitlab/config/entry/validators.rb
+++ b/lib/gitlab/config/entry/validators.rb
@@ -120,17 +120,13 @@ module Gitlab
 
           private
 
-          def look_like_regexp?(value)
-            value.is_a?(String) && value.start_with?('/') &&
-              value.end_with?('/')
+          def matches_syntax?(value)
+            Gitlab::UntrustedRegexp::RubySyntax.matches_syntax?(value)
           end
 
           def validate_regexp(value)
-            look_like_regexp?(value) &&
-              Regexp.new(value.to_s[1...-1]) &&
-              true
-          rescue RegexpError
-            false
+            matches_syntax?(value) &&
+              Gitlab::UntrustedRegexp::RubySyntax.valid?(value)
           end
         end
 
@@ -149,7 +145,7 @@ module Gitlab
 
           def validate_string_or_regexp(value)
             return false unless value.is_a?(String)
-            return validate_regexp(value) if look_like_regexp?(value)
+            return validate_regexp(value) if matches_syntax?(value)
 
             true
           end