/usr/share/go-1.6/src/crypto/md5/ is in golang-1.6-src 1.6.1-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/go-1.6/src/crypto/md5/example_test.go
/usr/share/go-1.6/src/crypto/md5/gen.go
/usr/share/go-1.6/src/crypto/md5/md5.go
/usr/share/go-1.6/src/crypto/md5/md5_test.go
/usr/share/go-1.6/src/crypto/md5/md5block.go
/usr/share/go-1.6/src/crypto/md5/md5block_386.s
/usr/share/go-1.6/src/crypto/md5/md5block_amd64.s
/usr/share/go-1.6/src/crypto/md5/md5block_amd64p32.s
/usr/share/go-1.6/src/crypto/md5/md5block_arm.s
/usr/share/go-1.6/src/crypto/md5/md5block_decl.go
/usr/share/go-1.6/src/crypto/md5/md5block_generic.go
/usr/share/go-1.6/src/crypto/md5/md5block_s390x.s