class PCO::URL::Encryption::Chunk

Public Class Methods

new(bytes) click to toggle source
# File lib/pco/url/encryption.rb, line 38
def initialize(bytes)
  @bytes = bytes
end

Public Instance Methods

decode() click to toggle source
# File lib/pco/url/encryption.rb, line 42
def decode # rubocop:disable Metrics/AbcSize
  bytes = @bytes.take_while { |c| c != 61 } # strip padding
  bytes = bytes.find_all { |b| !TABLE.index(b.chr).nil? } # remove invalid characters
  n = (bytes.length * 5.0 / 8.0).floor
  p = bytes.length < 8 ? 5 - (n * 8) % 5 : 0
  c = bytes.inject(0) { |m, o| (m << 5) + TABLE.index(o.chr) } >> p
  (0..(n - 1)).to_a.reverse.collect { |i| ((c >> i * 8) & 0xff).chr }
end
encode() click to toggle source
# File lib/pco/url/encryption.rb, line 51
def encode # rubocop:disable Metrics/AbcSize
  n = (@bytes.length * 8.0 / 5.0).ceil
  p = n < 8 ? 5 - (@bytes.length * 8) % 5 : 0
  c = @bytes.inject(0) { |m, o| (m << 8) + o } << p
  [
    (0..(n - 1)).to_a.reverse.collect { |i| TABLE[(c >> i * 5) & 0x1f].chr },
    ("=" * (8 - n))
  ]
end