#
#--
# Ronin - A Ruby platform designed for information security and data
# exploration tasks.
#
# Copyright (c) 2006-2009 Hal Brodigan (postmodern.mod3 at gmail.com)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#++
#

require 'ronin/arch'

require 'base64'

class String

  #
  # Packs the integer using the specified _arch_ and the given
  # _address_length_. The _address_length_ will default to the address
  # length of the _arch_.
  #
  #   0x41.pack(Arch('i686')) # => "A\000\000\000"
  #
  #   0x41.pack(Arch('ppc'),2) # => "\000A"
  #
  def depack(arch,address_length=arch.address_length)
    integer = 0x0

    if arch.endian=='little'
      address_length.times do |i|
        if self[i]
          integer = (integer | (self[i] << (i*8)))
        end
      end
    elsif arch.endian=='big'
      address_length.times do |i|
        if self[i]
          integer = (integer | (self[i] << ((address_length-i-1)*8)))
        end
      end
    end

    return integer
  end

  #
  # XOR encodes the string using the specified _key_.
  #
  def xor(key)
    encoded = ''

    each_byte { |b| encoded << (b ^ key).chr }
    return encoded
  end

  #
  # Returns the base64 encoded form of the string.
  #
  def base64_encode
    Base64.encode64(self)
  end

  #
  # Returns the base64 decoded form of the string.
  #
  def base64_decode
    Base64.decode64(self)
  end

end