The author doesn't indicate what version of Go they were attempting to use, but in the last two years, Go has seen many improvements by their very active dev te

The author doesn't indicate what version of Go they were attempting to use, but in the last two years, Go has seen many improvements by their very active dev team. Notably, there were several changes to crypto in 1.5: https://golang.org/doc/go1.5#minor_library_changes https://golang.org/doc/go1.5#minor_library_changes 1.6: https://golang.org/doc/go1.6#minor_library_changes https://golang.org/doc/go1.6#minor_library_changes and 1.7: https://golang.org/doc/go1.7#minor_library_changes https://golang.org/doc/go1.7#minor_library_changes