System::Security::Cryptography file enc/dec

enc-b.rb

require 'System'
require 'pp'

include System
include System::Text
include System::Security::Cryptography


class CredentialStore
  def initialize(file)
    @file = file
    @rijndaelAlg = Rijndael.create
    pp @rijndaelAlg.Key
    pp @rijndaelAlg.IV
  end

  def write(data)
    #Create or open the specified file.
    fStream = System::IO::File.open(@file, System::IO::FileMode.open_or_create)

    #Create a new Rijndael object.
    rijndaelAlg = Rijndael.create

    # Create a CryptoStream using the FileStream 
    # and the passed key and initialization vector (IV).
    cStream = CryptoStream.new(fStream, 
                          rijndaelAlg.CreateEncryptor(@rijndaelAlg.Key, @rijndaelAlg.IV),
                          CryptoStreamMode.Write)

    #Create a StreamWriter using the CryptoStream.
    sWriter = System::IO::StreamWriter.new(cStream)

    sWriter.write_line(data)

    sWriter.Close()
    cStream.Close()
    fStream.Close()
  end

  def read()
    #Create or open the specified file.
    fStream = System::IO::File.open(@file, System::IO::FileMode.open)

    #Create a new Rijndael object.
    rijndaelAlg = Rijndael.create

    # Create a CryptoStream using the FileStream 
    # and the passed key and initialization vector (IV).
    cStream = CryptoStream.new(fStream, 
                          rijndaelAlg.CreateDecryptor(@rijndaelAlg.Key, @rijndaelAlg.IV),
                          CryptoStreamMode.Read)

    #Create a StreamWriter using the CryptoStream.
    sReader = System::IO::StreamReader.new(cStream)

    d = sReader.read_line()
    sReader.Close()
    cStream.Close()
    fStream.Close()

    return d
  end
end

cs = CredentialStore.new("foo.dat")
cs.write("encrypted")
puts cs.read