RSA - creating key pair, encrypting and decrypting helpers

rsa.rb

# -*- encoding : utf-8 -*-

require 'openssl' 

module RSA
  
  def self.create_keys( priv = "rsa_key", pub = "#{priv}.pub", bits = 1024 )
    private_key = OpenSSL::PKey::RSA.new( bits )
    File.open( priv, "wb+" ) { |fp| fp << private_key.to_s }
    File.open( pub,  "wb+" ) { |fp| fp << private_key.public_key.to_s }
    private_key
  end
  
  def self.create_keys_in_memory( bits = 1024 )
    private_key = OpenSSL::PKey::RSA.new( bits )
    [private_key.public_key.to_s, private_key.to_s]
  end
  
  def self.encrypt( text, key )
    RSA::Key.new( key ).encrypt( text )
  end
  
  def self.decrypt( text, key )
    RSA::Key.new( key ).decrypt( text )
  end
  
  class Key
    def initialize( data )
      @public = ( data =~ /^-----BEGIN (RSA|DSA) PRIVATE KEY-----$/ ).nil?
      @key = OpenSSL::PKey::RSA.new( data )
    end
    
    def self.from_file( filename )
      self.new( File.read( filename ) )
    end
    
    def encrypt( text )
      Base64.encode64( @key.send("#{key_type}_encrypt", text ) )
    end
    
    def decrypt( text )
      @key.send( "#{key_type}_decrypt", Base64.decode64( text ) )
    end
    
    def private?
      !@public
    end
    
    def public?
      @public
    end
    
    def key_type
      public?  ?  :public  :  :private
    end
  end
  
end