Check an entire list of passwords against the Pwned Passwords V2 API

pwned.rb

#!/usr/bin/env ruby

require 'io/console'
require 'open-uri'
require 'digest'

IO.foreach("passwords.txt") do |line|
	password = line.strip
	hash = Digest::SHA1.hexdigest(password).upcase
	prefix = hash[0...5]

	url = "https://api.pwnedpasswords.com/range/#{prefix}"

	pwned = open(url) do |response|
	  Hash[response.each_line.map { |line|
	    suffix, count = line.strip.split(':')
	    [(prefix + suffix).upcase, count.to_i]
	  }]
	end

	count = pwned[hash]
	print "Password #{password} with SHA-1 hash #{hash} "
	if count
	  puts "has been pwned. Seen #{count} time#{count == 1 ? '' : 's'}."
	else
	  puts "has not been pwned."
	end
end