Strip comments before sending keys to gitlab-shell

Avoid issues with text encoding by not sending out non-7-bit ASCII
text.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22167

1 files changed, 11 insertions, 2 deletions

diff --git a/lib/gitlab/backend/shell.rb b/lib/gitlab/backend/shell.rb
index c412249a01e..79eac66b364 100644
--- a/lib/gitlab/backend/shell.rb
+++ b/lib/gitlab/backend/shell.rb
@@ -6,7 +6,12 @@ module Gitlab
 
     KeyAdder = Struct.new(:io) do
       def add_key(id, key)
-        key.gsub!(/[[:space:]]+/, ' ').strip!
+        key = Gitlab::Shell.strip_key(key)
+        # Newline and tab are part of the 'protocol' used to transmit id+key to the other end
+        if key.include?("\t") || key.include?("\n")
+          raise Error.new("Invalid key: #{key.inspect}")
+        end
+
         io.puts("#{id}\t#{key}")
       end
     end
@@ -16,6 +21,10 @@ module Gitlab
         @version_required ||= File.read(Rails.root.
                                         join('GITLAB_SHELL_VERSION')).strip
       end
+
+      def strip_key(key)
+        key.split(/ /)[0, 2].join(' ')
+      end
     end
 
     # Init new repository
@@ -107,7 +116,7 @@ module Gitlab
     #
     def add_key(key_id, key_content)
       Gitlab::Utils.system_silent([gitlab_shell_keys_path,
-                                   'add-key', key_id, key_content])
+                                   'add-key', key_id, self.class.strip_key(key_content)])
     end
 
     # Batch-add keys to authorized_keys