/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/ is in ruby-net-ssh 1:3.0.1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/abstract.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/md5.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/md5_96.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/none.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/ripemd160.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha1.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha1_96.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha2_256.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha2_256_96.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha2_512.rb
/usr/lib/ruby/vendor_ruby/net/ssh/transport/hmac/sha2_512_96.rb