Check if a password has been pwned with the Pwned Passwords V2 API

pwned.rb

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

puts "The 5-character prefix of the password's SHA-1 hash will be sent."
puts "For details, see https://www.troyhunt.com/ive-just-launched-pwned-passwords-version-2/"
print 'Password (hidden): '
password = $stdin.noecho(&:gets).strip
puts

hash = Digest::SHA1.hexdigest(password).upcase
prefix = hash[0...5]

url = "https://api.pwnedpasswords.com/range/#{prefix}"
print "Requesting #{url}. Continue (y/n)? "

if $stdin.gets.strip.downcase[0] != 'y'
  puts 'Canceled.'
  exit
end

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