/usr/lib/ruby/ is in liboauth-ruby1.8 0.4.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/1.8/
/usr/lib/ruby/1.8/digest/
/usr/lib/ruby/1.8/digest/hmac.rb
/usr/lib/ruby/1.8/oauth/
/usr/lib/ruby/1.8/oauth.rb
/usr/lib/ruby/1.8/oauth/cli.rb
/usr/lib/ruby/1.8/oauth/client/
/usr/lib/ruby/1.8/oauth/client.rb
/usr/lib/ruby/1.8/oauth/client/action_controller_request.rb
/usr/lib/ruby/1.8/oauth/client/em_http.rb
/usr/lib/ruby/1.8/oauth/client/helper.rb
/usr/lib/ruby/1.8/oauth/client/net_http.rb
/usr/lib/ruby/1.8/oauth/consumer.rb
/usr/lib/ruby/1.8/oauth/core_ext.rb
/usr/lib/ruby/1.8/oauth/errors/
/usr/lib/ruby/1.8/oauth/errors.rb
/usr/lib/ruby/1.8/oauth/errors/error.rb
/usr/lib/ruby/1.8/oauth/errors/problem.rb
/usr/lib/ruby/1.8/oauth/errors/unauthorized.rb
/usr/lib/ruby/1.8/oauth/helper.rb
/usr/lib/ruby/1.8/oauth/oauth.rb
/usr/lib/ruby/1.8/oauth/oauth_test_helper.rb
/usr/lib/ruby/1.8/oauth/request_proxy/
/usr/lib/ruby/1.8/oauth/request_proxy.rb
/usr/lib/ruby/1.8/oauth/request_proxy/action_controller_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/base.rb
/usr/lib/ruby/1.8/oauth/request_proxy/curb_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/em_http_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/jabber_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/mock_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/net_http.rb
/usr/lib/ruby/1.8/oauth/request_proxy/rack_request.rb
/usr/lib/ruby/1.8/oauth/request_proxy/typhoeus_request.rb
/usr/lib/ruby/1.8/oauth/server.rb
/usr/lib/ruby/1.8/oauth/signature/
/usr/lib/ruby/1.8/oauth/signature.rb
/usr/lib/ruby/1.8/oauth/signature/base.rb
/usr/lib/ruby/1.8/oauth/signature/hmac/
/usr/lib/ruby/1.8/oauth/signature/hmac/base.rb
/usr/lib/ruby/1.8/oauth/signature/hmac/md5.rb
/usr/lib/ruby/1.8/oauth/signature/hmac/rmd160.rb
/usr/lib/ruby/1.8/oauth/signature/hmac/sha1.rb
/usr/lib/ruby/1.8/oauth/signature/hmac/sha2.rb
/usr/lib/ruby/1.8/oauth/signature/md5.rb
/usr/lib/ruby/1.8/oauth/signature/plaintext.rb
/usr/lib/ruby/1.8/oauth/signature/rsa/
/usr/lib/ruby/1.8/oauth/signature/rsa/sha1.rb
/usr/lib/ruby/1.8/oauth/signature/sha1.rb
/usr/lib/ruby/1.8/oauth/token.rb
/usr/lib/ruby/1.8/oauth/tokens/
/usr/lib/ruby/1.8/oauth/tokens/access_token.rb
/usr/lib/ruby/1.8/oauth/tokens/consumer_token.rb
/usr/lib/ruby/1.8/oauth/tokens/request_token.rb
/usr/lib/ruby/1.8/oauth/tokens/server_token.rb
/usr/lib/ruby/1.8/oauth/tokens/token.rb