#!/usr/bin/env ruby -w
#
# Generates Sub-Resource Integrity hashes for external resources in HTML.
# See https://infosec.mozilla.org/guidelines/web_security#subresource-integrity
# 


url = ARGV.shift.to_s
unless url =~ %r{^https?://}
  $stderr.puts "usage: sri-integrity <url>"
  exit 1
end

hash = `curl -s '#{url}' | openssl dgst -sha384 -binary | openssl base64 -A`
if $?.success?
  puts hash
else
  exit 1
end