A really simple Ruby script to check password pwnage (because https://github.com/philnash/pwned isn't simple enough)

pwned

#!/usr/bin/env ruby
# Checks whether passwords have been pwned

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'excon'
end

require 'csv'
require 'digest'

PP = Excon.new('https://api.pwnedpasswords.com', persistent: true)

def check_password(password)
  password.chomp!
  hash = Digest::SHA1.hexdigest(password)
  prefix = hash.slice!(0..4)
  key = "#{hash.upcase}:"

  rows = PP.get(path: "/range/#{prefix}").body.lines
  result = rows.bsearch { |r| r >= key }
  return unless result&.start_with? key

  count = result.split(':').last.to_i
  puts "#{password}:#{count}"
end

# Read a firefox exported logins.csv
if ARGV.first == '--ff'
  ARGV.shift
  CSV.foreach(ARGV.shift, headers: true) { |r| check_password r['password'] }
# Iterate any files specified on the command line; or stdin
else
  ARGF.each_line { |p| check_password p }
end

Updated to add:

• Inline bundler for a nicer http client
• Swap to excon for persistent connection
• Binary search for faster checking of retrieved pages
• Ability to read from exported firefox CSV file