pwned.rb

require 'digest'
require 'net/http'

password = ARGV[0] || 'Password'
hashed_password = Digest::SHA1.hexdigest password

# SHA1 hashes will be 40 characters long
prefix = hashed_password[0, 5].to_s.upcase  # Get the first 5 characters
suffix = hashed_password[5..-1].to_s.upcase # Get the remaining 35 characters

puts "checking pwnedpasswords.com for: #{password}"
uri = URI("https://api.pwnedpasswords.com/range/#{prefix}")
res = Net::HTTP.get(uri)

puts res.split("\n").find { |pwned_password|
  pwned_password.start_with? suffix
}